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Sample records for borate glasses doped

  1. Spectroscopic studies of tantalum doped borate glasses

    NASA Astrophysics Data System (ADS)

    Sharada, M.; Suresh Babu, D.

    2012-10-01

    Glasses with formula 30Li2O 60B2O3xTa2O5 (10-x) Bi2O3 for x=0, 2, 4, 6 and 8 were prepared via normal melt quenching technique and characterized by refractive index and MDSC. Refractive index (?) and glass transition temperature (Tg) are found to increase with increase in dopant concentration. Impedance spectra of the samples were recorded in the frequency range 100 Hz-5 MHz in the temperature range 175-275 C. The plots are typical of those recorded for disordered systems. Conductivities and relaxation times are found to follow Arrhenius type of relation and activation energies are calculated. Optical absorption spectra were recorded in the wavelength range 200-900 nm range from which cutoff wavelength (?c) and optical band gap energy (Eg) are evaluated. ?c is found to decrease while Eg to increase with increase in composition. FTIR spectra of the samples were recorded in the frequency range 400-1500 cm-1 which exhibit characteristic bands corresponding to BO3, BO4 stretching vibrations and BO bending vibration. Tightening of the structure is indicated by increase in the vibration of BO3 at the cost of BO4 for 8 mol% of Ta2O5. This is in support of the highest value of Tg for this sample among the series. Raman spectra of the samples were recorded in the frequency range 200-1200 cm-1. With successive addition of Ta2O5, increase in the vibration of Ta-O groups TaO6 groups to be responsible for observed increase in ? and Tg. An attempt is made to prepare tantalum doped borate glasses and study them by spectroscopic techniques.

  2. Devitfrification Properties Of Bismuth Borate Glasses Doped With Trivalent Ions

    SciTech Connect

    Khanna, Atul; Bajaj, Anu

    2010-12-01

    Bismuth borate glasses and crystalline phases have outstanding luminescent and nonlinear optical properties; therefore there is lot of interest in their preparation and characterization. In this study we report the crystallization properties of bismuth borate glasses doped with trivalent ions. Glasses of the composition: xBi{sub 2}O{sub 3}-(100-x)B{sub 2}O{sub 3} (x = 20, 25, 30, 37.5, 40, 50, 60 and 66 mol %) and 40Bi{sub 2}O{sub 3}-1Tv{sub 2}O{sub 3}-59B{sub 2}O{sub 3}(where Tv = Al, Nd and Eu) were prepared by melt quench technique and devitrified by heat treatment above their glass transition temperatures for several hours. The crystalline phases produced were characterized by FTIR absorption spectroscopy, DTA and X-ray diffraction. Bi{sub 3}B{sub 5}O{sub 12} was found to be the predominant phase in all crystallized samples containing Bi{sub 2}O{sub 3} concentration of {<=}40 mol %, at higher Bi{sub 2}O{sub 3} concentration, we observed the formation of Bi{sub 4}B{sub 2}O{sub 9} phase. Glasses with Bi{sub 2}O{sub 3} concentration of {<=}37.5 mol % produced Bi{sub 2}B{sub 8}O{sub 15} phase on crystallization. The metastable BiBO{sub 3}-I phase was formed by short duration heat treatment (less than 5 hours) of the initial glass sample. Doping with rare earth ions like Eu{sup 3+} and Nd{sup 3+} promotes the formation of BiBO{sub 3}-II phase while Al{sup 3+} doping suppresses it.

  3. Synthesis and structural studies of praseodymium doped silver borate glasses

    SciTech Connect

    Jagadeesha Gowda, G. V.; Eraiah, B.

    2013-02-05

    Praseodymium doped silver borate glasses with nominal composition xPr{sub 6}O{sub 11}-(25-x)Ag{sub 2}O-75B{sub 2}O{sub 3} (x=0, 1, 2, 3, 4, 5) were prepared by melt quench technique. XRD pattern shows that there is no sharp peak it confirms the amorphous nature of the present glasses. The glass transition temperature (T{sub g}) of this glass system have been studied using the Matac MBS-8000 Digital Signal Processing and Conventional Thermal Analysis (DTA) method. The T{sub g} of these glasses increases with increase in concentration of Pr{sub 6}O{sub 11} except at 0.2 mol%, T{sub g} value is lower. {sup 11}B MAS-NMR shows the presence of sharp peak around 0.306 ppm. Chemical shift of these glasses decreases with mol% of rare earth oxide. FTIR spectra recorded in the region of 400 to 4000 cm{sup -1}. This studies revealed that the progressive addition Ag{sub 2}O and Pr{sub 6}O{sub 11} leads to modification of B{sub 2}O{sub 3} into BO{sub 4} groups. Raman measurements of these glasses support the proposed interpretations of the experimental results.

  4. Photoluminescent temperature sensor based on borate and phosphate glasses doped with copper clusters

    NASA Astrophysics Data System (ADS)

    Babkina, Anastasiia N.; Shirshnev, Pavel S.; Nikonorov, Nikolay V.; Sidorov, Alexander I.; Kolobkova, Elena V.

    2015-05-01

    The research of the luminescent properties of the inorganic glasses doped with copper molecular clusters that can be used as a sensitive medium of the temperature sensors is presented. The luminescent spectra of the borate and phosphate glasses in the temperature range 77-623 K are examined. The big luminescent thermochromism for borate glasses is observed: from 293K to 623K the luminescent band shift is found out to be 110nm.

  5. Tunable luminescence of Dy3+ single-doped and Dy3+/Tm3+ co-doped tungsten borate glasses

    NASA Astrophysics Data System (ADS)

    Hu, J.; Gong, X. H.; Chen, Y. J.; Huang, J. H.; Lin, Y. F.; Luo, Z. D.; Huang, Y. D.

    2014-12-01

    RE3+ (RE3+ = Tm3+, Dy3+) ion single and co-doped tungsten borate glasses for white light emitting diodes (LEDs) were prepared by melt quenching method. Emission and excitation spectra of the glasses were measured. The color of luminescence can be tuned by changing the composition of glass matrix or the concentrations of Tm3+ and Dy3+ ions. White light emission can be achieved from 0.5Dy3+ single-doped 15WO3-25La2O3-60B2O3 and 0.4Tm3+/1.5Dy3+ co-doped 50WO3-25La2O3-25B2O3 glasses. In addition, energy transfers between Tm3+ and Dy3+ were also analyzed. The Dy3+/Tm3+ co-doped tungsten borate glasses may be potential candidates for white LED application.

  6. Dosimetric properties of dysprosium doped lithium borate glass irradiated by 6 MV photons

    NASA Astrophysics Data System (ADS)

    Ab Rasid, A.; Wagiran, H.; Hashim, S.; Ibrahim, Z.; Ali, H.

    2015-07-01

    Undoped and dysprosium doped lithium borate glass system with empirical formula (70-x) B2O3-30 Li2O-(x) Dy2O3 (x=0.1, 0.3, 0.5, 0.7, 1.0 mol%) were prepared using the melt-quenching technique. The dosimetric measurements were performed by irradiating the samples to 6 MV photon beam using linear accelerator (LINAC) over a dose range of 0.5-5.0 Gy. The glass series of dysprosium doped lithium borate glass produced the best thermoluminescence (TL) glow curve with the highest intensity peak from sample with 1.0 mol% Dy2O3 concentration. Minimum detectable dose was detected at 2.24 mGy, good linearity of regression coefficient, high reproducibility and high sensitivity compared to the undoped glass are from 1.0 mol% dysprosium doped lithium borate glass. The results indicated that the series of dysprosium doped lithium glasses have a great potential to be considered as a thermoluminescence dosimetry (TLD).

  7. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions

    NASA Astrophysics Data System (ADS)

    Sathish, K.; Thirumaran, S.

    2015-08-01

    The present work describes the glass samples of composition (x% V2O5-(80-x)% B2O3-20% Na2CO3) VBS glass system and (x% MnO2-(80-x)% B2O3-20% Na2CO3) in MBS glass system with mol% ranging from x = 3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V2O5 doped glass system, (VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO2 doped glass system (VBS glass system). The present study critically observes the doping of V2O5 with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO2. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO3 or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na2CO3, V2O5 and MnO2 contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs.

  8. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions.

    PubMed

    Sathish, K; Thirumaran, S

    2015-08-01

    The present work describes the glass samples of composition (x% V₂O₅-(80-x)% B₂O₃-20% Na₂CO₃) VBS glass system and (x%MnO₂-(80-x)% B₂O₃-20% Na₂CO₃) in MBS glass system with mol% ranging from x=3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V₂O₅ doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO₂ doped glass system (VBS glass system). The present study critically observes the doping of V₂O₅ with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO₂. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO₃ or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na₂CO₃, V₂O₅ and MnO₂ contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs. PMID:25841150

  9. Effects of varying base glass composition on the optical properties of lead borate glasses doped with rare earth ions

    NASA Astrophysics Data System (ADS)

    Heidorn, William D.

    Rare Earth (RE) doped lead borate glasses are expected to exhibit a compositional dependence in their optical properties due to the changes induced by variations in the structure of the base glass with increasing lead oxide content. A series of lead borate glasses with the composition xPbO:(99.5 - x)B2O 3 (x = 29.5 to 69.5 in steps of 10 mol%) doped with 0.5 mol% Sm2O3, Er2O3, and Ho2O3 were prepared using the melt quench technique followed by 3 hours of annealing near the glass transition temperature. Optical absorption and fluorescence spectra of these RE doped lead borate glasses were analyzed using Judd-Ofelt theory. The compositional dependence of Judd-Ofelt intensity parameters, O t (t = 2, 4, 6), were determined and were then used to calculate the radiative transition probability of the excited states, the total radiative transition probability, branching ratios, and radiative lifetime of the glasses. From the fluorescence spectra the stimulated emission cross section, and Stark splitting of the excited states were calculated as a function of glass composition. A fourth set of samples with composition xPbO:(99 - x)B2O 3(x = 29 to 69 in steps of 10 mol%) co-doped with 0.5 mol% Er2 O3 and Ho2O3 were also prepared and the effects of co-doping on the absorption and fluorescence were analyzed. In all the glass systems studied, it was found that the optical properties are strongly influenced by structural changes arising from compositional variation. Er3+ transitions exhibit large stimulated cross section suggesting the possible utilization of these materials in laser applications. Keywords: Lead and bismuth borate glasses, fluorescence, optical absorption, Sm3+, Ho3+, Er3+ ions, Judd-Ofelt intensity parameters, stimulated emission cross section.

  10. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    NASA Astrophysics Data System (ADS)

    Omar, R. S.; Wagiran, H.; Saeed, M. A.

    2016-01-01

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B2O3 - 20 CaO - 10 MgO-(y) Dy2O3 with 0.05 mol % ≤ y ≤ 0.7 mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy2O3 concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  11. Optical spectroscopy of Dy3+ doped borate glasses for luminescence applications

    NASA Astrophysics Data System (ADS)

    Venkata Rao, K.; Babu, S.; Venkataiah, G.; Ratnakaram, Y. C.

    2015-08-01

    Dy3+ ion embedded in (50 - x)B2O3-20PbO-15MgF2-15NaCl-xDy2O3(x = 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0 mol%) borate glasses are prepared and investigated using Differential Thermal Analysis (DTA), X-ray Diffractometer (XRD), Raman spectra, optical absorption and photoluminescence (PL) as function of different concentrations. Thermal stability of borate glass has been calculated from DTA profiles. The amorphous nature of glass matrix is confirmed by XRD. Based on Raman spectra, the functional groups that are present in the glass matrices have been analyzed. Based on the Judd-Ofelt theory, three spectral intensity parameters Ωλ (λ = 2, 4, 6) are calculated from absorption spectra. These parameters are used to determine radiative transition probabilities (AR), radiative lifetimes (τR) and branching ratios (βR) of Dy3+ transitions from the excited state manifolds to corresponding lower laying multiplet manifolds. PL spectra show two intense and one weak band due to 4F9/2 → 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions respectively. For these transitions luminescence properties are studied. With the increase in the concentration of Dy3+ ions, intensity increases up to 0.8 mol% and then concentration quenching is observed. This is (0.8 mol%) the optimized concentration for the present prepared glasses. Lifetimes (τexp) are calculated for all the glass matrices from decay curve analysis. Spectroscopic and luminescence properties at 0.8 mol% doped dysprosium ion are compared with other reported glass matrices. From the above analysis suggest that 0.8 mol% of Dy3+ doped borate glasses can be useful for yellow lighting applications in the visible spectral region.

  12. Spectroscopic investigations on Pr+ and Nd+ doped strontium-lithium-bismuth borate glasses.

    PubMed

    Rajesh, D; Balakrishna, A; Seshadri, M; Ratnakaram, Y C

    2012-11-01

    Spectroscopic investigations on different concentrations (0.1, 0.5, 1.0, 1.5 and 2.0mol%) of Pr(3+) and Nd(3+) doped strontium lithium bismuth borate glasses have been done. X-ray diffraction, SEM with EDS, absorption and luminescence spectra were recorded for all the glass matrices and analyzed. X-ray diffraction profiles and SEM images conformed amorphous nature of investigated glass samples. EDS spectra of host glass and Pr(3+)doped glass matrices gave information about the chemical composition of glass samples. From the absorption spectra of Pr(3+) and Nd(3+) ions, Judd-Ofelt (J-O) intensity parameters (?(?),?=2, 4 and 6) have been calculated and compared with other glass matrices. The emission characteristics such as radiative lifetimes (?(R)), measured and calculated branching ratios (?) and stimulated emission cross-sections (?(P)) have been obtained for the observed emission transitions of Pr(3+) and Nd(3+) ions in the above glass matrix for all the concentrations. From the emission spectra of Pr(3+) and Nd(3+) doped glass matrices, the effect of concentration on the quenching of intensity of (1)D(2)?(3)H(4) transition of Pr(3+) ion and (4)F(3/2)?(4)I(9/2), (4)I(11/2) and (4)I(13/2) transitions of Nd(3+) have been studied and discussed. PMID:22925972

  13. Three-dimensional optical memory using photoluminescence change in Sm-doped sodium borate glass

    SciTech Connect

    Lim, Jinhyong; Lee, Myeongkyu; Kim, Eunkyoung

    2005-05-09

    The feasibility of three-dimensional (3D) optical memory has been demonstrated by utilizing the photoluminescence (PL) spectrum change in a Sm-doped fluoride glass [K. Miura, J. Qiu, S. Fujiwara, S. Sakasuchi, and K. Hirao, Appl. Phys. Lett. 80 2263 (2002)]. We here report on a femtosecond laser-induced PL change in a Sm-doped sodium borate glass that is easier to synthesize and its potential application to 3D memory. Irradiation with a femtosecond pulsed laser (800 nm, 1 kHz, 100 fs) induced a PL peak near 682 nm, resulting from the photoreduction of the Sm ions. A multilayer pattern (bit size=1 {mu}m,layer separation=8 {mu}m) formed by femtosecond laser irradiation was read out by a reflection-type fluorescent confocal microscope, which detected the emission at 682 nm as a signal. High-contrast pattern images were obtained without crosstalk.

  14. Elastic properties of silver borate glasses doped with praseodymium oxide

    SciTech Connect

    Gowda, G. V. Jagadeesha; Eraiah, B.

    2014-04-24

    A series of glasses xPr{sub 6}O{sub 11−}(35−x) Ag{sub 2}O−65B{sub 2}O{sub 3} with x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol % were synthesized by melt quenching technique. Longitudinal and shear ultrasonic velocity were measured at 5 MHz frequency and at room temperature. Elastic moduli, Poisson's ratio and Debye temperature have been calculated from the measured density and ultrasonic velocity at room temperature. The experimental results indicate that the elastic constants depend upon the composition of the glasses. The role of the Pr{sub 6}O{sub 11} inside the glass network was discussed.

  15. Optical Properties of Alkaline Earth Ions Doped Bismuth Borate Glasses

    SciTech Connect

    Kundu, Virender; Dhiman, R. L.; Maan, A. S.; Goyal, D. R.

    2011-07-15

    The optical properties of glasses with composition xLi{sub 2}O(30-x)Bi{sub 2}O{sub 3}-70B{sub 2}O{sub 3}; x = 0, 5, 10, 15 and 20 mol %, prepared by normal melt quench technique were investigated by means of UV-VIS measurement. It was observed that the optical band gap of the present glass system decreases with increasing Li{sub 2}O content up to 15 mol%, and with further increase in lithium oxide content i.e. x>15 mol% the optical band gap increases. It was also observed that the present glass system behaves as an indirect band gap semiconductor.

  16. Optical properties of Nd3+ doped bismuth zinc borate glasses.

    PubMed

    Shanmugavelu, B; Venkatramu, V; Ravi Kanth Kumar, V V

    2014-03-25

    Glasses with compositions of (100-x) (Bi2ZnOB2O6) -x Nd2O3 (where x=0.1, 0.3, 0.5, 1 and 2 mol%) were prepared by melt quenching method and characterized through optical absorption, emission and decay curve measurements. Optical absorption spectra have been analyzed using Judd-Ofelt theory. The emission spectra exhibit three peaks at 919, 1063 and 1337 nm corresponding to (4)F3/2 to (4)I9/2, (4)I11/2 and (4)I13/2 transitions in the near infrared region. The emission intensity of the (4)F3/2 to (4)I11/2 transition increases with increase of Nd(3+) concentration up to 1 mol% and then concentration quenching is observed for 2 mol% of Nd(3+) concentration. The lifetimes for the (4)F3/2 level are found to decrease with increase in Nd2O3 concentration in the glasses. The decay curves of the glass up to 0.3 mol% of Nd(3+) exhibit single exponential nature and thereafter the curves become nonexponential nature (0.5, 1 and 2 mol%). The nonexponential curve has been fitted to the Inokuti-Hirayama model to understand the nature of energy transfer process. PMID:24326260

  17. Optical and structural properties of lithium sodium borate glasses doped Dy3+ ions

    NASA Astrophysics Data System (ADS)

    Dawaud, Raghda Saeif Eddin Said; Hashim, Suhairul; Alajerami, Yasser Saleh Mustafa; Mhareb, M. H. A.; Tamchek, N.

    2014-10-01

    Absorption and emission spectra of lithium sodium borate glass doped with different concentrations of Dy3+ have been reported. The concentration of Dy3+ was varied from 0.3 to 1.3 mol%. The amorphous nature of the prepared samples was confirmed by the X-ray Diffraction (XRD). Fourier transforms infrared (FTIR) spectra, and other significant physical properties (energy band gap, density, ion concentration, molar volume, Polaron radius and inter-nuclear distance) have been analyzed in the light of the different oxidation states of the co-dopant ions. The absorption spectrum showed nine peaks with hypersensitive transition corresponding to 6F11/2 + 6H9/2 at 1256 nm. As a result of 380 nm excitation wavelength, the luminescence spectra showed two characteristic bands at 479 nm and 587 nm. These absorption bands were attributed to 6P15/2 ? 6H15/2 and 6P15/2 ? 6H13/2 transitions of trivalent Dy3+ ions. The current study indicates that Dy doped lithium sodium borate glasses are attractive for solid-state laser applications.

  18. Optical studies of Sm³⁺ ions doped zinc alumino bismuth borate glasses.

    PubMed

    Swapna, K; Mahamuda, Sk; Srinivasa Rao, A; Shakya, S; Sasikala, T; Haranath, D; Vijaya Prakash, G

    2014-05-01

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of samarium (Sm(3+)) ions were prepared by using melt quenching technique and characterized for their lasing potentialities in visible region by using the techniques such as optical absorption, emission and emission decay measurements. Radiative properties for various fluorescent levels of Sm(3+) ions were estimated from absorption spectral information using Judd-Ofelt (JO) analysis. The emission spectra and con-focal photoluminescence images obtained by 410 nm laser excitation demonstrates very distinct and intense orange-red emission for all the doped glasses. The suitable concentration of Sm(3+) ions in these glasses to act as an efficient lasing material has been discussed by measuring the emission cross-section and branching ratios for the emission transitions. The quantum efficiencies were also been estimated from emission decay measurements recorded for the (4)G5/2 level of Sm(3+) ions. From the measured emission cross-sections, branching ratios, strong photoluminescence features and CIE chromaticity coordinates, it was found that 1 mol% of Sm(3+) ions doped ZnAlBiB glasses are most suitable for the development of visible orange-red lasers. PMID:24530709

  19. The Preparation and Characterization of Nd2O3 Doped Borate Glass

    NASA Astrophysics Data System (ADS)

    Razali, Wan Aizuddin Wan; Kasim, Azman; Mohamed, Ruziana

    2010-07-01

    The Nd3+ doped borate glass of Nd2O3-MgO-ZnO-B2O3 glass system is successfully been prepared by melt-quenched technique. Batches of 15g were prepared from certified reagent grades of B2O3 (99.95% purity), MgO (97%), ZnO (98% purity), and Nd2O3 (99.99%). The measured glass densities are found varies from 5683.2 kgm-3 to 5724.0 kgm-3. The increment in density implies that an addition of Nd2O3 with higher atomic masses than B2O3 tend to increase the packing density of the glass structures since the atomic masses of B2O3 and Nd2O3 are 69.62 and 336.42 respectively. From the density values obtained, the molar volume of glasses was calculated. From the results, it is found that the molar volume of these glasses decreases slightly from 22.50 cm3 to 27.54 cm3 with respect to Nd2O3 content.

  20. Spectroscopic Study on Eu3+ Doped Borate Glasses Containing Ag Nanoparticles and Ag Aggregates.

    PubMed

    Fu, Shaobo; Zheng, Hui; Zhang, Jinsu; Li, Xiangping; Sun, Jiashi; Hua, Ruinian; Dong, Bin; Xia, Haiping; Chen, Baojiu

    2015-01-01

    Transparent Eu(3+)-doped borate glasses containing Ag nanoparticles and Ag aggregates with composition (40 - x) CaO-59.5B2O3-0.5Eu2O3-xAgNO3 were prepared by a simple one-step melt-quenching technique. The X-ray diffraction (XRD) patterns of the glasses reveal amorphous structural properties and no diffraction peaks belonging to metal Ag particles. Ag particles and Ag aggregates were observed from the absorption spectra. Effective energy transfers from the Ag aggregates to the Eu3+ ions were observed in the excitation spectra from monitoring the intrinsic emission of Eu3+x .5D0 --> 7F2. The glasses with higher Ag content can be effectively excited by light in a wide wavelength region, indicating that these glasses have potential application in the solid state lighting driven by semiconductor light emitting diodes (LEDs). The emission spectra of the samples with higher Ag contents exhibit plenteous spectral components covering the full visible region from violet to red, thus indicating that these glass materials possess an excellent and tunable color rendering index. The color coordinates for all the glass samples were calculated by using the intensity-corrected emission spectra and the standard data issued by the CIE (Commission International de l' Eclairage) in 1931. It was found that the color coordinates for most samples with higher Ag contents fall into the white region in the color space. PMID:26328363

  1. The Preparation and Characterization of Nd{sub 2}O{sub 3} Doped Borate Glass

    SciTech Connect

    Razali, Wan Aizuddin Wan; Kasim, Azman; Mohamed, Ruziana

    2010-07-07

    The Nd{sup 3+} doped borate glass of Nd{sub 2}O{sub 3}-MgO-ZnO-B{sub 2}O{sub 3} glass system is successfully been prepared by melt-quenched technique. Batches of 15g were prepared from certified reagent grades of B{sub 2}O{sub 3}(99.95% purity), MgO (97%), ZnO (98% purity), and Nd{sub 2}O{sub 3}(99.99%). The measured glass densities are found varies from 5683.2 kgm{sup -3} to 5724.0 kgm{sup -3}. The increment in density implies that an addition of Nd{sub 2}O{sub 3} with higher atomic masses than B{sub 2}O{sub 3} tend to increase the packing density of the glass structures since the atomic masses of B{sub 2}O{sub 3} and Nd{sub 2}O{sub 3} are 69.62 and 336.42 respectively. From the density values obtained, the molar volume of glasses was calculated. From the results, it is found that the molar volume of these glasses decreases slightly from 22.50 cm{sup 3} to 27.54 cm{sup 3} with respect to Nd{sub 2}O{sub 3} content.

  2. Thermoluminescence Response of Copper-Doped Potassium Borate Glass Subjected to 6 Megavolt X-Ray Irradiation

    NASA Astrophysics Data System (ADS)

    Hossain, I.; Shekaili, N. K.; Wagiran, H.

    2015-03-01

    This study addresses the characteristics of Cu-doped and undoped potassium borate glass for use as ionizing radiation dosimeters by investigating and comparing the thermoluminescence responses, linearity, sensitivity and dose response s of the two types of glasses. A number of samples based on xK 2 CO 3 + (100 - x)H 3 BO 3 , where 10 ≤ x ≤ 30 mol.%, have been prepared using a melt quenching technique. The amorphous phases were identified using X-ray diffraction (XRD). The undoped potassium borate samples 20K 2 CO 3 + 80H 3 BO 3 (mol.%) and Cu-doped (0.5 mol.%) samples were placed in a solid phantom apparatus and irradiated with in X-ray tube under 6 MV accelerating voltage with doses ranging from 0.5 to 4.0 Gy. This beam was produced by the Primus MLC 3339 linear accelerator (LINAC) available at Hospital Sultan Ismail, Johor Bahru, Malaysia. The results clearly show the superiority of Cu-doped glass in terms of response and sensitivity to producing luminescence over undoped potassium borate glass. The sensitivity of Cu-doped glass is 6.75 times greater than that of undoped glass.

  3. Optical absorption and heating rate dependent glass transition in vanadyl doped calcium oxy-chloride borate glasses

    NASA Astrophysics Data System (ADS)

    Dahiya, M. S.; Khasa, S.; Agarwal, A.

    2015-04-01

    Some important results pertaining to optical and thermal properties of vanadyl doped oxy-halide glasses in the chemical composition CaCl2-CaO-B2O3 are discussed. These glasses have been prepared by conventional melt quench technique. From X-ray diffraction (XRD) profiles the amorphous nature of the doped glasses has been confirmed. The electronic polarizability is calculated and found to increase with increase in chloride content. The optical absorption spectra have been recorded in the frequency range of 200-3200 nm. Recorded spectra are analyzed to evaluate cut-off wavelength (λcut-off), optical band gap (Eg), band tailing (B), Urbach energy (ΔE) and refractive index (n). Thermal analysis has been carried out for the prepared glasses at three different heating rates viz. 5, 10 and 20 °C/min. The glass transition temperature (Tg) along with thermal activation energy (Ea) corresponding to each heating rate are evaluated from differential scanning calorimetry (DSC) thermographs. It is found that Ea decrease and Tg increase with increase in heating rate. The variation in Tg is also observed with the substitution of calcium chloride in place of calcium oxide. The increasing and higher values of Ea suggest that prepared glasses have good thermal stability. Variation in Tg and Eg suggests that Cl- anions enter into the voids of borate network at low concentrations (<5.0%) and contribute to the network formation at high concentration (>5.0%).

  4. Optical properties of lithium magnesium borate glasses doped with Dy3+ and Sm3+ ions

    NASA Astrophysics Data System (ADS)

    Alajerami, Yasser Saleh Mustafa; Hashim, Suhairul; Wan Hassan, Wan Muhamad Saridan; Termizi Ramli, Ahmad; Kasim, Azman

    2012-07-01

    Several studies showed the interesting properties of trivalent lanthanide ions when doped in various types of glasses. Optical and physical properties of lithium magnesium borate glasses doped with Dy3+ then with Sm3+ ions were determined by measuring their absorption and luminescence spectra in the visible region. The absorption spectra of Dy3+ showed eight absorption bands with hypersensitive transition at 1265 nm (6H15/2?6F11/2-6H9/2) and three PL emission bands at 588 nm (4F9/2?6H15/2), 660 nm (4F9/2?6H13/2) and 775 nm (4F9/2?6H11/2). Regarding the Sm3+, nine absorption bands were observed with hypersensitive transition at 1237 nm (6H5/2-6F7/2); the PL spectrum showed four prominent peaks at 4G5/2?6H5/2 (yellow color), 4G5/2?6H7/2 (bright orange color), 4G5/2?6H9/2 (orange reddish color) and 4G5/2?6H11/2 (red color), respectively. Finally, a series of physical parameters such as the oscillator strengths, refractive index, ions concentration, Polaron radius and other parameters were calculated for each dopant.

  5. Structural and optical properties of lithium sodium borate glasses doped with Sm3+ ions

    NASA Astrophysics Data System (ADS)

    Dawaud, R. S. E. S.; Hashim, S.; Alajerami, Y. S. M.; Mhareb, M. H. A.; Maqableh, M. M.; Tamchek, N.

    2014-07-01

    Absorption and emission spectra of Sm3+ doped lithium sodium borate (LNB) have been reported. The samples were prepared by the melt-quenching technique and characterized by X-ray diffraction (XRD), diffraction thermal analysis (DTA), Fourier transforms infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM). From the thermo-grams spectrum, glass transition (Tg), crystallization (Tc) and melting temperatures (Tm) have been evaluated. Direct and indirect optical band gaps have been calculated based on the glasses UV absorption spectra. These glasses have shown strong nine absorption bands with hypersensitive transition at 1221 nm (6H5/2?4H3/2) and five emission bands for the transition at 4I7/2?6H13/2 (green color), 4I7/2?6H7/2 (orange color), 4I7/2?6H9/2 (orange color), 4I7/2?6H11/2 (red color) and 4I7/2?6H13/2 (red color) with performing an excitation of 400 nm. The oscillator strengths, refractive index, ions concentration, polaron radius and other parameters have been calculated for each dopant.

  6. Ho3+-doped strontium-aluminium-bismuth-borate glasses for green light emission.

    PubMed

    Rajesh, D; Dhamodhara Naidu, M; Ratnakaram, Y C; Balakrishna, A

    2014-11-01

    Strontium-aluminium-bismuth-borate glasses (SAlBiB) doped with different concentrations of Ho(3+) were prepared using conventional melt quenching technique and their structural and optical properties investigated. X-ray diffraction and scanning electron microscopy analysis were used to study the structural properties. Optical properties were studied by measuring the optical absorption and visible luminescence spectra. The Judd-Ofelt (J-O) theory was applied to evaluate J-O intensity parameters, Ω(λ) (λ = 2, 4 and 6). Using J-O intensity parameters, radiative properties such as spontaneous transition probabilities (A(R)), branching ratios (β(R)) and radiative lifetimes (τ(R)) were determined. From the emission spectra, a strong green emission nearly at 549 nm corresponding to the transition, (5)S2 ((5)F4)→(5)I(8) was observed. Emission peak positions (λ(P)), effective bandwidths (Δλ(eff)) and stimulated emission cross-sections (σ(p)) were calculated for the observed emission transitions, (5)F3 →(5)I(8), (5)S2((5)F4)→(5)I(8) and (5)F5 →(5)I(8) of Ho(3+) in all the glass matrices. Chromaticity color coordinates were calculated using the emission spectra. The experimental results suggest that SAlBiB glass matrix with 1.5 mol% of Ho(3+) has better emission properties. PMID:24519914

  7. Thermoluminescence properties of the Cu-doped lithium potassium borate glass.

    PubMed

    Aboud, Haydar; Wagiran, H; Hussin, R; Ali, Hassan; Alajerami, Yasser; Saeed, M A

    2014-08-01

    Characteristics of lithium potassium borate glasses with various copper concentrations are reported. The glasses were prepared by the melt quenching method and irradiated with photons to doses in the 0.5-4.0 Gy range. Glowing curves, dose response curves, reproducibility of the response, dose threshold, thermal fading and optical bleaching were studied. PMID:24681645

  8. Random lasing in Eu3+ doped borate glass-ceramic embedded with Ag nanoparticles under direct three-photon excitation

    NASA Astrophysics Data System (ADS)

    Xu, Xuhui; Zhang, Wenfei; Jin, Limin; Qiu, Jianbei; Yu, Siu Fung

    2015-10-01

    We report the observation of random lasing from Eu3+ doped borate glass ceramic films embedded with Ag nanoparticles through three-photon absorption at room temperature. Under 1179 nm ultrashort femtosecond pulse excitation, discrete sharp peaks with linewidth ~0.4 nm emerge randomly from a broad emission band with peak wavelength at ~612 nm. In addition, the number of sharp peaks increases with the increase of excitation power. We also show that the emission spectrum varies with different observation angles and the corresponding lasing threshold is dependent on the excitation area. Hence, we verify unambiguously that the Eu3+ doped borate glass ceramic film supports random lasing action via three-photon absorption excitation. In addition, Ag nanoparticles, which act as light scatterers, allow the formation of random microcavities inside the bulk film.

  9. Effect of 3d-transition metal doping on the shielding behavior of barium borate glasses: a spectroscopic study.

    PubMed

    ElBatal, H A; Abdelghany, A M; Ghoneim, N A; ElBatal, F H

    2014-12-10

    UV-visible and FT infrared spectra were measured for prepared samples before and after gamma irradiation. Base undoped barium borate glass of the basic composition (BaO 40%-B2O3 60mol.%) reveals strong charge transfer UV absorption bands which are related to unavoidable trace iron impurities (Fe(3+)) within the chemical raw materials. 3d transition metal (TM)-doped glasses exhibit extra characteristic absorption bands due to each TM in its specific valence or coordinate state. The optical spectra show that TM ions favor generally the presence in the high valence or tetrahedral coordination state in barium borate host glass. Infrared absorption bands of all prepared glasses reveal the appearance of both triangular BO3 units and tetrahedral BO4 units within their characteristic vibrational modes and the TM-ions cause minor effects because of the low doping level introduced (0.2%). Gamma irradiation of the undoped barium borate glass increases the intensity of the UV absorption together with the generation of an induced broad visible band at about 580nm. These changes are correlated with suggested photochemical reactions of trace iron impurities together with the generation of positive hole center (BHC or OHC) within the visible region through generated electrons and positive holes during the irradiation process. PMID:24983922

  10. Waveguides and nonlinear index of refraction of borate glass doped with transition metals

    NASA Astrophysics Data System (ADS)

    Almeida, Juliana M. P.; Fonseca, Ruben D.; De Boni, Leonardo; Diniz, Andre Rosa S.; Hernandes, Antonio C.; Ferreira, Paulo H. D.; Mendonca, Cleber R.

    2015-04-01

    The ability to write 3D waveguides by femtosecond laser micromachining and the nonlinear refractive index (n2) spectrum of a new borate glass matrix, containing zinc and lead oxides - (BZP) have been investigated. The transparent matrix was doped with transition metals (CdCl2, Fe2O3, MnO2 and CoO) in order to introduce electronic transitions in visible spectrum, aiming to evaluate their influence on the waveguides and n2 spectrum. We observed that n2 is approximately constant from 600 to 1500 nm, exhibiting an average value of 4.5 × 10-20 m2/W, which is about twice larger than the one for fused silica. The waveguide profile is influenced by the self-focusing effect of the matrix owing to its positive nonlinear index of refraction in the wavelength used for micromachining. A decrease in the waveguide loss of approximately four times was observed for the sample doped with Fe in comparison to the other ones, which may be associated with the change in the optical gap energy.

  11. Optical properties of Lead bismuth borate glasses doped with neodymium oxide.

    PubMed

    Farouk, M; Abd El-Maboud, A; Ibrahim, M; Ratep, A; Kashif, I

    2015-10-01

    Neodymium doped Lead bismuth borate glasses with the composition of 25PbO-25Bi2O3-50B2O3:xNd2O3, where x=0.5, 1, 1.5 and 2 mol%, have been prepared by melt quenching technique. The behavior of the density and molar volume allows concluding that, addition of Nd2O3 leads to the formation of non-bridging oxygen. Rare earth ion parameters have been calculated and studied. The optical band gap (Eg), and band tails (Ee) were determined. Judd-Ofelt theory for the intensity analysis of induced electric dipole transitions has been applied to the measured oscillator strengths of the absorption bands to determine the three phenomenological intensity parameters Ω2, Ω4 and Ω6 for glass. It was observed that the deviation parameters, rms, was found to be 0.56:0.58(×10(-6)). The estimated Judd-Ofelt parameters were found to be Nd2O3concentration dependent. The hypersensitive transition, (4)I9/2→(4)G5/2+(2)G7/2, is closely related to Ω2 parameter. PMID:25965518

  12. Broad-spectrum antibacterial properties of metal-ion doped borate bioactive glasses for clinical applications

    NASA Astrophysics Data System (ADS)

    Ottomeyer, Megan

    Bioactive glasses with antimicrobial properties can be implemented as coatings on medical devices and implants, as well as a treatment for tissue repair and prevention of common hospital-acquired infections such as MRSA. A borate-containing glass, B3, is also undergoing clinical trials to assess wound-healing properties. The sensitivities of various bacteria to B3, B3-Ag, B3-Ga, and B3-I bioactive glasses were tested. In addition, the mechanism of action for the glasses was studied by spectroscopic enzyme kinetics experiments, Live-Dead staining fluorescence microscopy, and luminescence assays using two gene fusion strains of Escherichia coli. It was found that gram-positive bacteria were more sensitive to all four glasses than gram negative bacteria, and that a single mechanism of action for the glasses is unlikely, as the rates of catalysis for metabolic enzymes as well as membrane permeability were altered after glass exposure.

  13. One-photon band gap engineering of borate glass doped with ZnO for photonics applications

    SciTech Connect

    Abdel-Baki, Manal; Abdel-Wahab, Fathy A.; El-Diasty, Fouad

    2012-04-01

    Lithium tungsten borate glass of the composition (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0 {<=}x{<=} 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B{sub 2}O{sub 3} by ZnO.

  14. The structural, optical and magnetic parameter of manganese doped strontium zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Sumalatha, B.; Omkaram, I.; Rajavardhana Rao, T.; Linga Raju, Ch.

    2013-02-01

    Glasses with composition 10SrO:(30-x)ZnO:60B2O3:xMnO, 0?x?0.9 (all compositions in wt%) have been prepared and investigated by X-ray diffraction, EPR, Optical absorption and FT-IR spectroscopic techniques. The XRD pattern of all the glasses confirmed the formation of an amorphous structure. The EPR spectra of all glass samples exhibit resonance signals at g?2.0 with a sextet of hyperfine lines. The spin concentration (N) and temperature dependence of EPR signals were studied for Mn2+ ions in strontium zinc borate glass samples. The zero-field splitting parameter D has been evaluated from the intensities of the allowed hyperfine lines. The paramagnetic susceptibility (?) was calculated from EPR data at different temperatures and the Curie temperature (?p) was calculated from the 1/? verses T graph. The optical absorption spectra exhibit a single broad band near 470 nm and this has been attributed to the spin-allowed 5Eg?5T2g transition of Mn3+ ions in octahedral symmetry. The theoretical optical basicity (?th) of these glasses have also been evaluated. The FTIR studies show BO3 and BO4 structural units in strontium zinc borate glasses.

  15. Extended X-ray Absorption Fine Structure (EXAFS) Analysis of Zirconium-Doped Lithium Silicate/Borate Glass-Ceramics

    NASA Astrophysics Data System (ADS)

    Yoo, Changhyeon; Marasinghe, Kanishka; Segre, Carlo; Brow, Richard K.

    2015-03-01

    Results of Zr K-edge Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy analysis of a series of Zr-doped (~ 3-10 mol% Zr and atomic ratio Li/Si ~ 0.8) lithium silicate glass ceramics (ZLS) and their parent glasses and a series of Zr-doped (~ 2-6 mol% Zr and atomic ratio Li/B ~ 0.25-0.18) lithium borate (ZLB) glasses are presented. Immediate coordination environment of all ZLS samples, i.e. the parent glasses and glass ceramics prepared via two different techniques, are remarkably similar. This observation suggests that zirconium ions may remain in the glass phase during nucleation and crystallization process. In contrast, immediate coordination environment of ZLB glasses appear to change markedly with the Zr concentration. These results also suggest that the structural role of Zr ions in ZLS and ZLB glasses may be significantly different. Details of analysis and results will be presented. Support was provised by NSF (UND) and DoE (argonne Natl. Lab).

  16. Thermoluminescence dosimetry properties and kinetic parameters of lithium potassium borate glass co-doped with titanium and magnesium oxides.

    PubMed

    Hashim, S; Alajerami, Y S M; Ramli, A T; Ghoshal, S K; Saleh, M A; Abdul Kadir, A B; Saripan, M I; Alzimami, K; Bradley, D A; Mhareb, M H A

    2014-09-01

    Lithium potassium borate (LKB) glasses co-doped with TiO2 and MgO were prepared using the melt quenching technique. The glasses were cut into transparent chips and exposed to gamma rays of (60)Co to study their thermoluminescence (TL) properties. The TL glow curve of the Ti-doped material featured a single prominent peak at 230 °C. Additional incorporation of MgO as a co-activator enhanced the TL intensity threefold. LKB:Ti,Mg is a low-Z material (Z(eff)=8.89) with slow signal fading. Its radiation sensitivity is 12 times lower that the sensitivity of TLD-100. The dose response is linear at doses up to 10(3) Gy. The trap parameters, such as the kinetics order, activation energy, and frequency factor, which are related to the glow peak, were determined using TolAnal software. PMID:24929526

  17. Photon Interaction Parameters for Some Borate Glasses

    SciTech Connect

    Mann, Nisha; Kaur, Updesh; Singh, Tejbir; Sharma, J. K.; Singh, Parjit S.

    2010-11-06

    Some photon interaction parameters of dosimetric interest such as mass attenuation coefficients, effective atomic number, electron density and KERMA relative to air have been computed in the wide energy range from 1 keV to 100 GeV for some borate glasses viz. barium-lead borate, bismuth-borate, calcium-strontium borate, lead borate and zinc-borate glass. It has been observed that lead borate glass and barium-lead borate glass have maximum values of mass attenuation coefficient, effective atomic number and KERMA relative to air. Hence, these borate glasses are suitable as gamma ray shielding material, packing of radioactive sources etc.

  18. Precipitation of ZnO in Al 2O 3-doped zinc borate glass ceramics

    NASA Astrophysics Data System (ADS)

    Masai, Hirokazu; Ueno, Takahiro; Takahashi, Yoshihiro; Fujiwara, Takumi

    2011-10-01

    Crystallization behavior of the oxide semiconductor ZnO in zinc borate glass was investigated. The precipitated crystalline phase of glass ceramics containing a small amount of Al 2O 3 was α-Zn 3B 2O 6 whereas that of the glass ceramics containing a large amount of Al 2O 3 was ZnO. It was found that the c-oriented precipitation of ZnO in a glass ceramic was brought about by the in-plane crystal growth of needle-like ZnO crystallites along the a-axis. Amount of Al 2O 3 that can make glass network affected the coordination state of B 2O 3 in the glass, and a three-coordinated BO 3 unit was preferentially formed in the glass containing a higher amount of Al 2O 3. The present results suggest that crystallization of ZnO from multi-component glass is dominated by the local coordination state of the mother glass.

  19. Role of oxygen on the optical properties of borate glass doped with ZnO

    SciTech Connect

    Abdel-Baki, Manal; El-Diasty, Fouad

    2011-10-15

    Lithium tungsten borate glass (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0{<=}x{<=}0.1 mol%) is prepared by the melt quenching technique for photonic applications. Small relative values of ZnO are used to improve the glass optical dispersion and to probe as well the role of oxygen electronic polarizability on its optical characteristics. The spectroscopic properties of the glass are determined in a wide spectrum range (200-2500 nm) using a Fresnel-based spectrophotometric technique. Based on the Lorentz-Lorenz theory, as ZnO content increases on the expense of B{sub 2}O{sub 3} the glass molar polarizability increased due to an enhanced unshared oxide ion 2p electron density, which increases ionicity of the chemical bonds of glass. The role of oxide ion polarizability is explained in accordance with advanced measures and theories such as optical basicity, O 1s binding energy, the outer most cation binding energy in Yamashita-Kurosawa's interionic interaction parameter and Sun's average single bond strength. FT-IR measurements confirm an increase in bridging oxygen bonds, as a result of replacement of ZnO by B{sub 2}O{sub 3}, which increase the UV glass transmission window and transmittance. - Graphical abstract: O1s, Yamashita-Kurosawa's parameter and average single bond strength of charge overlapping between electronic shells are used to explain enhanced oxide ion 2p electron density, which increases refractive index of glasses. Highlights: > New borate glass for photonic application is prepared. > The dispersion property of the glass is effectively controlled using small amounts of ZnO. > ZnO is used to probe the glass structure and investigate the role of oxygen on the obtained optical properties of the glasses. > Modern theories are used to explain enhanced unshared oxide ion 2p electron density, which increases ionicity of chemical bonds of the glass.

  20. Visible red, NIR and Mid-IR emission studies of Ho3+ doped Zinc Alumino Bismuth Borate glasses

    NASA Astrophysics Data System (ADS)

    Mahamuda, Sk.; Swapna, K.; Packiyaraj, P.; Srinivasa Rao, A.; Vijaya Prakash, G.

    2013-12-01

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Holmium were prepared by conventional melt quenching technique. The glassy nature of these glasses has been confirmed through the XRD spectral measurements. The FTIR spectra recorded for undoped glass revealed the information related to the functional groups involved in the host glass. Optical absorption, excitation and photoluminescence spectra of these glasses have been recorded at room temperature. The Judd-Ofelt theory has been applied successfully to characterize the absorption spectra of the ZnAlBiB glasses. From this theory various radiative properties such as radiative transition probability (AR), radiative lifetimes (?R), branching ratios (?R) and spectroscopic quality factor (?) for the prominent emission levels 5F5 ? 5I7, 5F5 ? 5I8 and 5I7 ? 5I8 have been evaluated. The photoluminescence spectra revealed the quenching of luminescence intensity beyond 1.0 mol% of Ho3+ ion concentration in ZnAlBiB glasses. To investigate the lasing potentiality of 5F5 ? 5I7, 5F5 ? 5I8 and 5I7 ? 5I8 transitions, the effective band width (??p) and the stimulated emission cross-section (?se) were determined. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for visible red laser emission in principle.

  1. Contribution of Eu ions on the precipitation of silver nanoparticles in Ag-Eu co-doped borate glasses

    SciTech Connect

    Jiao, Qing; Qiu, Jianbei; Zhou, Dacheng; Xu, Xuhui

    2014-03-01

    Graphical abstract: - Highlights: • Silver nanoparticles are precipitated from the borate glasses during the melting process without any further heat treatment. • The reduction of Eu{sup 3+} ions to Eu{sup 2+} ions is presented in this material. • The intensity of Ag{sup +} luminescence. • The introduction of Eu ions accelerated the reaction between Eu{sup 2+} ions and silver ions inducing the silver clusters formation. - Abstract: Ag{sup +} doped sodium borate glasses with different Eu ions concentration were prepared by the melt-quenching method. The absorption at about 410 nm which was caused by the surface plasmon resonance (SPR) of Ag nanoparticles (NPs) is promoted with increasing of Eu ions concentration. Meanwhile, the luminescent spectra showed that the emission intensity of Ag{sup +} decreased while that of the Ag aggregates increased simultaneously. The results indicated that the Ag ions intend to form the high-polymeric state such as Ag aggregates and nanoparticles with increasing of europium ions. Owing to the self-reduction of Eu{sup 3+} to Eu{sup 2+} in our glass system, it revealed that Ag{sup +} has been reduced by the neighboring Eu{sup 2+} which leads to the formation of Ag aggregates and the precipitation of Ag NPs in the matrix. In addition, energy transfer (ET) process from Ag{sup +}/Ag aggregates to the Eu{sup 3+} was investigated for the enhancement of Eu{sup 3+} luminescence.

  2. FTIR studies of some vanadyl ion doped calcium oxychloride borate glasses

    NASA Astrophysics Data System (ADS)

    Khasa, S.; Dahiya, M. S.; Agarwal, A.

    2013-06-01

    The borate glass system with composition xCaCl2ṡ(30-x)ṡCaOṡ70B2O3+2mol% of V2O5(x = 0,0.02,0.05,0.07,0.10,0.12,0.15,0.20,0.25,0.30) has been prepared with the traditional melt-quenching technique. The FTIR study has been carried out using Perkin Elmer Frontier FTIR with ATR accessory in the mid IR range. The density, molar theoretical optical basicity is calculated so as to determine the structure and covalency in the glass network so formed. The spectra reveal absence of boroxol ring and presence of absorption bands corresponding to the combined contributions of tri and tetra borate stretching vibrations. This confirms the network modifier nature of magnesium chloride. The increasing basicity reveals decrease in the covalence nature of oxygen and octahedral enhancement in the vanadyl ion nature as we replace the CaO content with CaCl2. The increase in molar volume may be due to the increase in openness of the network structure.

  3. Identification of ε-Fe2O3 nano-phase in borate glasses doped with Fe and Gd

    NASA Astrophysics Data System (ADS)

    Ivanova, O. S.; Ivantsov, R. D.; Edelman, I. S.; Petrakovskaja, E. A.; Velikanov, D. A.; Zubavichus, Y. V.; Zaikovskii, V. I.; Stepanov, S. A.

    2016-03-01

    A new type of magnetic nanoparticles was revealed in borate glasses co-doped with low contents of iron and gadolinium. Structure and magnetic properties of the particles differ essentially from that of the α-Fe2O3, γ-Fe2O3, or Fe3O4 nanoparticles which were detected earlier in similar glass matrices. Transmission electron microscopy including STEM-HAADF and EDX, synchrotron radiation-based XRD, static magnetic measurements, magnetic circular dichroism, and electron magnetic resonance studies allow referring the nanoparticles to the iron oxide phase-ε-Fe2O3. Analysis of the data set has shown that it is Gd atoms that govern the process of nanoparticles' nucleation and its incorporation into the particles in different proportions can be used to adjust their magnetic and magneto-optical characteristics.

  4. Spectroscopic properties and luminescence behaviour of europium doped lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Anjaiah, J.; Laxmikanth, C.; Veeraiah, N.

    2014-12-01

    Li2O-MO-B2O3 (MO=ZnO, CaO and CdO) glasses doped with europium are prepared by using the melt quenching technique to study their absorption and luminescence properties to understand their lasing potentialities. The XRD pattern of the glasses confirmed the amorphous nature and the IR spectra reveal the presence of BO3 and BO4 units in the glass network. Judd-Ofelt intensity parameters Ωλ (λ=2, 4, 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. The J-O parameters have been used to calculate transition probabilities (A), lifetime (τR), branching ratios (βR) and stimulated emission cross-section (σP) for the 5D0→7FJ (J=1-4) transitions of the Eu3+ ions. The decay from the 5D0 level of Eu3+ ions in these glasses has been measured and analysed. Branching ratios and stimulated emission cross-sections measured for all these glasses show that the 5D0→7F1 transition under investigation has the potential for laser applications. The high stimulated emission cross-section and branching ratios from the present glasses suggests their potential for infra red lasers. The study of the thermoluminescence is also carried out and the data suggests that the CdBEu glass is suitable for thermoluminescence emission output among the three Eu3+ doped glasses.

  5. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide.

    PubMed

    Mhareb, M H A; Hashim, S; Ghoshal, S K; Alajerami, Y S M; Saleh, M A; Razak, N A B; Azizan, S A B

    2015-12-01

    We report the impact of dysprosium (Dy(3+) ) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+) . An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg ), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2 O-MgO-B2 O3 radiation dosimeters. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25828828

  6. Effect of Bi2O3 on spectroscopic and structural properties of Er3+ doped cadmium bismuth borate glasses.

    PubMed

    Sanghi, S; Pal, I; Agarwal, A; Aggarwal, M P

    2011-12-01

    Glasses with composition 20CdOxBi(2)O(3)(79.5-x)B(2)O(3) (15?x?35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters ?(?) (?=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (?(R)), branching ratios (?(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (?(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)?(4)I(15/2) at 1.506 ?m in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication. PMID:21890402

  7. Effect of co-doped SnO{sub 2} nanoparticles on photoluminescence of cu-doped potassium lithium borate glass

    SciTech Connect

    Namma, Haydar Aboud; Wagiran, H.; Hussin, R.; Ariwahjoedi, B.

    2012-09-26

    The SnO{sub 2} co-doped lithium potassium borate glasses doped with 0.05, 0.10, 0.25 and 0.50 mol% of Cu were synthesized by the melt quenching technique. The SnO{sub 2} co-dope was added to the compounds in the amounts of 0.05, 0.10, and 0.20 mol%. The photoluminescent spectrum for different concentrations of copper was studied. It was observed that the intensity of blue emission (450, 490 nm) varies with concentration mol%. In addition, with different concentration of SnO{sub 2} to 0.10 mol% Cu, the influence of the luminescence has been observed to enhance intensity and shifted to blue and red (490, 535 nm) emissions.

  8. Degradable borate glass polyalkenoate cements.

    PubMed

    Shen, L; Coughlan, A; Towler, M; Hall, M

    2014-04-01

    Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag2O-Na2O-CaO-SrO-ZnO-TiO2-B2O3 were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO2 (7.5 mol %) tended to have longer working times and shorter setting times. Dissolution behavior of the four model GPC formulations was evaluated by measuring ion release profiles as a function of time. All four GPC formulations showed evidence of incongruent dissolution behavior when considering the relative release profiles of sodium and boron, although the exact dissolution profile of the glass was presumably obscured by the polymeric cement matrix. Compression testing was undertaken to evaluate cement strength over time during immersion in water. The cements containing the borate glass with 7.5 mol % TiO2 had the highest initial compressive strength, ranging between 20 and 30 MPa. No beneficial aging effect was observed-instead, the strength of all four model GPC formulations was found to degrade with time. PMID:24435528

  9. Luminescent properties of lithium-phosphate-borate glasses doped with Tb3+/ Eu3+ ions

    NASA Astrophysics Data System (ADS)

    Valiev, D. T.; Stepanov, S. A.; Cong, Liu

    2016-02-01

    The luminescence of Li2O-B2O3-P2O5-CaF2 scintillation glass doped Tb3+, Eu3+ under different types of excitation sources are investigated. Changing the europium concentration of 0.5 to 1 wt% leads changes in luminescence intensity of Tb3+ ions. The luminescence spectrum of the Tb3+ ions are depend on the concentration of Eu3+. It was found, that the luminescence decay kinetics of terbium ion in the band 543 nm depending on the concentration of europium and from type of excitation. The difference in the nature of the luminescence decay kinetics of glasses under pulsed photo- and electronic excitation discussed.

  10. Random lasing in Eu³⁺ doped borate glass-ceramic embedded with Ag nanoparticles under direct three-photon excitation.

    PubMed

    Xu, Xuhui; Zhang, Wenfei; Jin, Limin; Qiu, Jianbei; Yu, Siu Fung

    2015-10-21

    We report the observation of random lasing from Eu(3+) doped borate glass ceramic films embedded with Ag nanoparticles through three-photon absorption at room temperature. Under 1179 nm ultrashort femtosecond pulse excitation, discrete sharp peaks with linewidth ∼0.4 nm emerge randomly from a broad emission band with peak wavelength at ∼612 nm. In addition, the number of sharp peaks increases with the increase of excitation power. We also show that the emission spectrum varies with different observation angles and the corresponding lasing threshold is dependent on the excitation area. Hence, we verify unambiguously that the Eu(3+) doped borate glass ceramic film supports random lasing action via three-photon absorption excitation. In addition, Ag nanoparticles, which act as light scatterers, allow the formation of random microcavities inside the bulk film. PMID:26377118

  11. Optical and FTIR structural studies of CoO-doped sodium borate, sodium silicate and sodium phosphate glasses and effects of gamma irradiation-a comparative study

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; ElBatal, F. H.; ElBatal, H. A.; EzzElDin, F. M.

    2014-09-01

    Undoped and CoO-doped three binary glass systems, namely sodium borate, sodium silicate and sodium phosphate glasses were prepared by the melt annealing technique. Combined optical and FTIR spectral studies were carried out for the prepared samples before and after being subjected to a gamma dose of 8 Mrad (8 × 104 Gy). Optical spectra of the undoped samples before irradiation reveal strong UV absorption varying in depth with the type of glass and such strong UV spectra are related to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of these three basic glasses. CoO-doped (0.25%) glasses show additional visible absorption spectra which are related to the existence of cobalt in the divalent state (Co)2+ ions which are present in two coordination states, namely the octahedral and tetrahedral forms. The broad visible band of Co2+ ions shows in some instances obvious splitting to three component peaks. Gamma irradiation on undoped glasses causes obvious induced UV-visible bands and their extension depends on the type of glass system. Irradiation of CoO-doped glasses causes an obvious increase of absorption within the visible region. Infrared absorption spectra of the undoped three basic glasses reveal IR vibrational bands which are characteristics to the three specific characteristic structural building units within the borate, silicate and phosphate glasses. The introduction of CoO with the doping level causes minor variations of the IR spectra because of the low doping content together with the presence of cobalt ions in structural modifying sites. Gamma irradiation is observed to cause limited changes within the intensities of some bands in the IR spectra which are attributed to changes in bond lengths and/or bond angles of the structural building units by the irradiation process.

  12. Er3+-doped strontium lithium bismuth borate glasses for broadband 1.5 μm emission - optical properties

    NASA Astrophysics Data System (ADS)

    Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

    2013-02-01

    Strontium lithium bismuth borate glasses (SLBiB) doped with various concentrations of Er3+ were prepared using conventional melt quench technique and investigated their optical properties. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction and SEM analysis. Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra at room temperature. Judd-Ofelt (J-O) theory has been applied for the f.f transitions of Er3+ ions to evaluate J-O intensity parameters, Ωλ (λ = 2, 4 and 6). Using the J-O intensity parameters, radiative properties such as transition probabilities (AR), branching ratios (β) and radiative lifetimes (τ) are estimated for certain transitions. From the emission spectra, peak emission-cross sections (σp) and products of stimulated emission cross-section and full width at half maximum (σp×FWHM) were calculated for the observed emission transition, 4I13/2→4I15/2.

  13. Physical, structural and spectroscopic investigations of Sm3+ doped ZnO mixed alkali borate glass

    NASA Astrophysics Data System (ADS)

    Sailaja, B.; Joyce Stella, R.; Thirumala Rao, G.; Jaya Raja, B.; Pushpa Manjari, V.; Ravikumar, R. V. S. S. N.

    2015-09-01

    Glass of 20ZnO-15 Li2O-15 Na2O-49.9 B2O3 doped with 0.1 mol% of Sm3+ (ZLNB) was prepared by the melt quenching technique. Physical properties were studied and analysed. The XRD studies confirm the amorphous nature of sample. The FT-IR spectral investigation discloses the BO3, BO4 groups, H and OH bonds. Optical absorption and emission spectra were recorded and characterized. Judd-Ofelt theory was applied to f ↔ f transitions to evaluate Judd-Ofelt intensity parameters (Ωλ). The oscillator strengths and bonding parameters were determined from absorption spectra. The trend observed was Ω4 > Ω6 > Ω2. High value of Ω4 reveals higher rigidity and covalency around the Sm3+ ion. Low value of Ω2 implies ionic nature of ligands and site symmetry around Sm3+ ion. luminescence data and Judd-Ofelt parameters Ωλ (λ = 2, 4, and 6) were used to evaluate various radiative probabilities like spontaneous radiative emission probabilities (AR), radiative lifetime (τR) and branching ratios (βR) stimulated emission cross section (σe) and CIE colour coordinates were measured, CCT temperature evaluated and the values were used to ascertain potential laser transitions at the optimum mixed alkali effect observed for the glass sample prepared. The preparedness of the material as the efficient laser active material is examined.

  14. Glass composition and excitation wavelength dependence of the luminescence of Eu{sup 3+} doped lead borate glass

    SciTech Connect

    Wen Hongli; Duan, Chang-Kui; Jia Guohua; Tanner, Peter A.; Brik, Mikhail G.

    2011-08-01

    This work explores the relationship between the bandwidth of luminescence spectral features and their relative intensities, using glasses doped with europium, Eu{sup 3+}, over a wide composition range. Glasses of composition (B{sub 2}O{sub 3}){sub 70}(PbO){sub 29}(0.5Eu{sub 2}O{sub 3}){sub 1} and (B{sub 2}O{sub 3}){sub z}(PbO){sub 99.6-z}(0.5Eu{sub 2}O{sub 3}){sub 0.4}, (z = 20, 30, 40, 60, 70), were prepared by the melting-quenching technique. Variable-wavelength measurements by the prism-coupling method enabled interpolation of refractive index at selected wavelengths. Diffuse reflectance spectra confirmed the incorporation of Eu{sup 3+} into the glass, and scanning electron microscopy displayed that this was in a homogeneous manner. Vibrational spectra showed a change in boron coordination from BO{sub 3} to BO{sub 4} units with increase of PbO content in the glass. Multi-wavelength excited luminescence spectra were recorded for the glasses at temperatures down to 10 K and qualitative interpretations of spectral differences with change of B{sub 2}O{sub 3} content are given. The quantitative analysis of {sup 5}D{sub 0} luminescence intensity-bandwidth relations showed that although samples with higher boron content closely exhibit a simple proportional relationship with band intensity ratios, as expected from theory, the expression needs to be slightly modified for those with low boron content. The Judd-Ofelt intensity analysis of the {sup 5}D{sub 0} emission spectra under laser excitations at low temperature gives {Omega}{sub 2} values within the range from (3.9-6.5) x 10{sup -20} cm{sup 2}, and {Omega}{sub 4} in the range from (4.1-7.0) x 10{sup -20} cm{sup 2}, for different values of z. However, no clear monotonic relation was found between the parameter values and composition. The Judd-Ofelt parameters are compared with those from other systems doped with Eu{sup 3+} and are found to lie in the normal ranges for Eu{sup 3+}-doped glasses. The comparison of parameter values derived from the 10 K spectra with those from room temperature spectra for our glasses, which are fairly constant for different compositions, shows that site selection occurs at low temperature.

  15. Spectroscopy and energy transfer in lead borate glasses doubly doped with Dy(3)(+)-Tb(3+) and Tb(3)(+)-Eu(3+) ions.

    PubMed

    Pisarska, Joanna; Kos, Agnieszka; Pisarski, Wojciech A

    2014-08-14

    Lead borate glasses doubly doped with Dy(3)(+)-Tb(3+) and Tb(3+)-Eu(3+) were investigated using optical spectroscopy. Luminescence spectra of rare earths were detected under various excitation wavelengths. The main green emission band due to (5)D4→(7)F5 transition of Tb(3+) is observed under excitation of Dy(3+), whereas the main red emission band related to (5)D0→(7)F2 transition of Eu(3+) is successfully observed under direct excitation of Tb(3+). In both cases, the energy transfer processes from Dy(3+) to Tb(3+) and from Tb(3+) to Eu(3+) in lead borate glasses occur through a nonradiative processes with efficiencies up to 16% and 18%, respectively. The presence of energy transfer process was also confirmed by excitation spectra measurements. PMID:24824577

  16. Crystallization of lithium borate glasses

    NASA Technical Reports Server (NTRS)

    Goktas, A. A.; Neilson, G. F.; Weinberg, M. C.

    1992-01-01

    The glass-forming ability and crystallization behavior of lithium borate compositions, in the diborate-to-metaborate-range, were studied. In particular, the nature and sequence of formation of crystalline phases and the tendency toward devitrification were investigated as functions of temperature, thermal history and batch composition. It was found that the sequence of crystalline phase formation was sensitive to all of the three latter factors, and it was observed that under certain conditions metastable defect structures of the metaborate can appear.

  17. Structural study and DC conductivity of vanadyl doped zinc lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Seema, Khasa, S.; Dahiya, M. S.; Yadav, Arti; Agarwal, A.; Dahiya, S.

    2015-06-01

    Glasses with composition xZnOṡ(30 - x)ṡLi2Oṡ70B2O3 containing 2 mol% of V2O5 (x = 0, 2, 5, 7 and 10) were prepared by standard melt-quench technique. The amorphous nature of the glass samples was confirmed by using x-ray diffraction. The structural changes in these glasses have been investigated by employing IR spectroscopy in the mid-IR range. The infrared spectroscopic analysis confirms the presence of both triangular and tetraheldral coordinated boron units and absence of boroxol ring. It also shows that metal-oxide vibrations are present which are due to the bonding of lithium and zinc ions with oxygen. The dc conductivity was measured in the temperature range 353-523 K. The dc conductivity results show that conductivity decreases and activation energy increases when Li2O is replaced by ZnO, keeping the concentration of B2O3 constant. Decrease in conductivity and increase in activation energy shows that addition of ZnO to the glass matrix shows a "blocking effect" on the overall mobility of alkali ions, but at higher concentration the hopping effect was also observed.

  18. Structural and physical properties of vanadium doped copper bismuth borate glasses

    SciTech Connect

    Dhiman, R. L.; Kundu, Virender Singh; Arora, Susheel; Maan, A. S.

    2013-02-05

    The structural and physical properties of xCuO(30-x)Bi{sub 2}O{sub 3}-70B{sub 2}O{sub 3}; x= 0, 5, 10, 15, 20 and 25 mol % with 2 mol %V{sub 2}O{sub 5} glasses prepared by normal melt quench technique have been investigated by means of FT-IR and physical measurement techniques. With the addition of copper oxide (x{<=} 10 mol%), the frequency bands in the higher region shift towards lower wave number, suggest the conversion of BO{sub 3} to BO{sub 4} structural units, which in turn give rise to the formation of Non Bridging Oxygen's (NBOs). For further increase in CuO (i.e. for x{>=} 10 mol %), the frequency bands shift towards higher wave number, indicate the formation of Bridging Oxygen's (BOs). The FTIR analysis reveals that the present glass system is based on the BiO{sub 3} pyramidal, BiO{sub 6} octahedral units and also on BO{sub 3} and BO{sub 4} structural units. The systematic variation in density and molar volume in these glasses indicates the effect of CuO substitution.

  19. Wound dressings composed of copper-doped borate bioactive glass microfibers stimulate angiogenesis and heal full-thickness skin defects in a rodent model.

    PubMed

    Zhao, Shichang; Li, Le; Wang, Hui; Zhang, Yadong; Cheng, Xiangguo; Zhou, Nai; Rahaman, Mohamed N; Liu, Zhongtang; Huang, Wenhai; Zhang, Changqing

    2015-01-01

    There is a need for better wound dressings that possess the requisite angiogenic capacity for rapid in situ healing of full-thickness skin wounds. Borate bioactive glass microfibers are showing a remarkable ability to heal soft tissue wounds but little is known about the process and mechanisms of healing. In the present study, wound dressings composed of borate bioactive glass microfibers (diameter = 0.4-1.2 μm; composition 6Na2O, 8K2O, 8MgO, 22CaO, 54B2O3, 2P2O5; mol%) doped with 0-3.0 wt.% CuO were created and evaluated in vitro and in vivo. When immersed in simulated body fluid, the fibers degraded and converted to hydroxyapatite within ∼7 days, releasing ions such as Ca, B and Cu into the medium. In vitro cell culture showed that the ionic dissolution product of the fibers was not toxic to human umbilical vein endothelial cells (HUVECs) and fibroblasts, promoted HUVEC migration, tubule formation and secretion of vascular endothelial growth factor (VEGF), and stimulated the expression of angiogenic-related genes of the fibroblasts. When used to treat full-thickness skin defects in rodents, the Cu-doped fibers (3.0 wt.% CuO) showed a significantly better capacity to stimulate angiogenesis than the undoped fibers and the untreated defects (control) at 7 and 14 days post-surgery. The defects treated with the Cu-doped and undoped fibers showed improved collagen deposition, maturity and orientation when compared to the untreated defects, the improvement shown by the Cu-doped fibers was not markedly better than the undoped fibers at 14 days post-surgery. These results indicate that the Cu-doped borate glass microfibers have a promising capacity to stimulate angiogenesis and heal full-thickness skin defects. They also provide valuable data for understanding the role of the microfibers in healing soft tissue wounds. PMID:25890736

  20. [Ce3⁺/Tb3⁺ Doped Alkaline-Earth Borate Glasses Employed in Enhanced Solar Cells].

    PubMed

    Yang, Peng; Zhao, Xin; Wang, Zhi-qiang; Lin, Hai

    2015-12-01

    Ce³⁺ and Tb³⁺ doped alkaline earth borate (LKZBSB) glasses and the photoluminescence properties of glass system have been fabricated and investigated, and the observed violet and green fluorescences are originated from Ce³⁺ and Tb³⁺ emit- ting centers, respectively. Four emission bands peaked at 487, 543, 586 and 621 nm are attributed to the emission transitions ⁵D₄-->⁷F₆, ⁵D₄-->⁷F₅, ⁵D₄-->⁷F₄ and ⁵D₄-->⁷F₃ of Tb³⁺, respectively, and consists of a broad emission band peaking at 389 nm attributed to 5d--4ƒ electric dipole allowed transition of Ce³⁺. With the introduction of Ce³⁺, the effective excitation wavelength range of Tb³⁺ in LKZBSB glasses are remarkably expanded, and the enhanced factor of green fluorescence of Tb³⁺ in Ce³⁺/Tb³⁺ co-doped LKZBSB glasses is up to 73 times in medium-wavelength ultraviolet (UVB) excitation region, compared with that in Tb³⁺ single-doped case. The results show that the conversion from ultraviolet (UV) radiation to visible light is efficient in Ce³⁺/ Tb³⁺ doped LKZBSB glasses, demonstrating that the glasses have potential values in developing enhanced solar cell as a conver- sion layer. PMID:26964196

  1. Cooperative luminescence sensitisation and spontaneous Raman scattering in a borate glass doped with Pr{sup 3+} and Nd{sup 3+} ions

    SciTech Connect

    Chanturiya, G F; Kutaladze, L M; Tatarashvili, R A; Shchegolikhin, Aleksandr N

    2004-04-30

    Cooperative sensitisation of luminescence of Nd{sup 3+} ions at the {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 13/2}, {sup 4}I{sub 9/2} transitions by Pr{sup 3+} ions was observed in a borate glass doped with Pr{sup 3+}-Nd{sup 3+} ion pairs. The luminescence was excited by a 800-mW, 1.064-{mu}m Nd{sup 3+}:YAG laser. Simultaneously, spontaneous Raman scattering was observed in glasses containing Pr{sup 3+}-Nd{sup 3+} ion pairs or only Pr{sup 3+} ions. The Stokes shift from the 9398-cm{sup -1} excitation line is 794 cm{sup -1}. The mechanism of nonradiative energy transfer is discussed. (laser applications and other topics in quantum electronics)

  2. Regulation of structure rigidity for improvement of the thermal stability of near-infrared luminescence in Bi-doped borate glasses.

    PubMed

    Guo, Qiangbing; Xu, Beibei; Tan, Dezhi; Wang, Juechen; Zheng, Shuhong; Jiang, Wei; Qiu, Jianrong; Zhou, Shifeng

    2013-11-18

    The effect of heat-treatment on the near-infrared (NIR) luminescence properties was studied in Bi-doped borate glasses. The luminescence intensity generally decreases with the increase of temperature, and the thermal stability can be improved by nearly 4.5 times with addition of 5 mol% La2O3. Collaborative studies by using steady photoluminescence (PL) and photoluminescence excitation (PLE) spectra, luminescence decay curve, differential thermal analysis (DTA), Raman spectra and X-ray diffraction (XRD) indicate that the luminescence decrement is associated with the agglomeration of Bi active centers during heat-treatment. The improvement of the thermal stability of NIR luminescence with the addition of La2O3 is benefited from the enhancement of structure rigidity due to the strong cationic field strength of La3+. The results not only provide valuable guidance for suppressing performance degradation of Bi-doped glass during fiber drawing process, but also present an effective way to control the luminescence properties of main group elements in glasses from the perspective of glass structure. PMID:24514300

  3. Comparative study of ion conducting pathways in borate glasses

    SciTech Connect

    Hall, Andreas; Swenson, Jan; Adams, Stefan

    2006-11-01

    The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity.

  4. Er{sup 3+}-doped strontium lithium bismuth borate glasses for broadband 1.5 {mu}m emission - optical properties

    SciTech Connect

    Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

    2013-02-05

    Strontium lithium bismuth borate glasses (SLBiB) doped with various concentrations of Er{sup 3+} were prepared using conventional melt quench technique and investigated their optical properties. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction and SEM analysis. Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra at room temperature. Judd-Ofelt (J-O) theory has been applied for the f.f transitions of Er{sup 3+} ions to evaluate J-O intensity parameters, {Omega}{lambda} ({lambda} = 2, 4 and 6). Using the J-O intensity parameters, radiative properties such as transition probabilities (A{sub R}), branching ratios ({beta}) and radiative lifetimes ({tau}) are estimated for certain transitions. From the emission spectra, peak emission-cross sections ({sigma}{sub p}) and products of stimulated emission cross-section and full width at half maximum ({sigma}{sub p} Multiplication-Sign FWHM) were calculated for the observed emission transition, {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2}.

  5. Effect of WO 3 on the spectroscopic properties in Er 3+/Yb 3+ co-doped bismuth-borate glasses

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Zhou, Yaxun; Dai, Shixun; Xu, Tiefeng; Nie, Qiuhua

    2007-11-01

    The spectroscopic properties of Er 3+/Yb 3+ co-doped Bi 2O 3-B 2O 3-WO 3 (BBW) glasses were analyzed and discussed. The effect of WO 3 content on the absorption spectra, the Judd-Ofelt parameters Ω t ( t=2, 4, 6), emission spectra and the lifetime of the 4I 13/2 level and the quantum efficiency of Er 3+: 4I 13/2→ 4I 15/2 transition were also investigated. With the substitution of WO 3 for B 2O 3, the measured lifetime of the 4I 13/2 level and the quantum efficiency of Er 3+: 4I 13/2→ 4I 15/2 transition increase from 0.98 to 1.31 ms and from 38.2% to 49.2%, respectively. The effective width of emission band and the emission cross-section both decrease slightly. And the emission spectra is analyzed via the different curve ( σe- σa) of BBW glasses, the influence of OH - is also discussed.

  6. Borates

    USGS Publications Warehouse

    Angulo, M.A.

    2011-01-01

    The article discusses the latest developments in the borates industry, particularly in the U.S., as of June 2011. It claims that the biggest economically feasible deposits of borates are seen in the U.S.' Mojave Desert, the Alpide belt in southern Asia and the Andean belt of South America. Turkish state-owned mining firm Eti Maden AS reported that borates were mainly used in the manufacture of glass, ceramics, fertilizer and detergent in 2009.

  7. Interfacial reactions between titanium and borate glass

    SciTech Connect

    Brow, R.K.; Saha, S.K.; Goldstein, J.I.

    1992-12-31

    Interfacial reactions between melts of several borate glasses and titanium have been investigated by analytical scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). A thin titanium boride interfacial layer is detected by XPS after short (30 minutes) thermal treatments. ASEM analyses after longer thermal treatments (8--120 hours) reveal boron-rich interfacial layers and boride precipitates in the Ti side of the interface.

  8. Towards modeling gadolinium-lead-borate glasses

    SciTech Connect

    Rada, S.; Ristoiu, T.; Rada, M.; Coroiu, I.; Maties, V.; Culea, E.

    2010-01-15

    Infrared spectra of gadolinium-lead-borate glasses of the xGd{sub 2}O{sub 3}.(100 - x)[3B{sub 2}O{sub 3}.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd{sub 2}O{sub 3}.(1 - x)[3B{sub 2}O{sub 3}.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd{sub 2}O{sub 3} causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO{sub 4}] units into trigonal [BO{sub 3}] units. Then, gadolinium ions have affinity towards [BO{sub 3}] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO{sub 3}] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B{sub 2}O{sub 3}.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  9. Variation of photoluminescence features in Pr3+ doped lithium-fluoro-borate glass by changing different modifier oxides (MgO, CaO, CdO and PbO)-Judd-Ofelt theory application

    NASA Astrophysics Data System (ADS)

    Balakrishna, A.; Rajesh, D.; Babu, S.; Ratnakaram, Y. C.

    2015-06-01

    Pr3+ (1.0 mol%) doped different modifier oxide based six lithium-fluoro-borate glasses with chemical composition of 49Li2B4O7-20BaF2-10NaF-20MO (where M= Mg, Ca, Cd and Pb), 49Li2B4O7-20BaF2-10NaF-10MgO-10CaO and 49Li2B4O7-20BaF2-10NaF-10CdO-10PbO were prepared by conventional melt quenching technique. Judd-Ofelt theory has been applied for evaluating the Judd-Ofelt intensity parameters for Pr3+ ion in these glass compositions and are in turn to used to predict radiative properties such as radiative transition probabilities (AT), branching ratios (β) and stimulated emission cross-section (σP). Stimulated emission cross-section (σp) of prominent emission transitions, 3P0→3H4 and 1D2→3H4 of Pr3+ ion in all lithium-fluoro-borate glasses were calculated. Among all the emission transitions, 3P0→3H4 posseses higher branching ratio and stimulated emission cross-section in Mg-Ca glass, which leads to the best laser excitation at 487 nm wavelength.

  10. Angiogenic effects of borate glass microfibers in a rodent model.

    PubMed

    Lin, Yinan; Brown, Roger F; Jung, Steven B; Day, Delbert E

    2014-12-01

    The primary objective of this research was to evaluate the use of bioactive borate-based glass microfibers for angiogenesis in soft tissue repair applications. The effect of these fibers on growth of capillaries and small blood vessels was compared to that of 45S5 silica glass microfibers and sham implant controls. Compressed mats of three types of glass microfibers were implanted subcutaneously in rats and tissues surrounding the implant sites histologically evaluated 2-4 weeks post surgery. Bioactive borate glass 13-93B3 supplemented with 0.4 wt % copper promoted extensive angiogenesis as compared to silica glass microfibers and sham control tissues. The angiogenic responses suggest the copper-containing 13-93B3 microfibers may be effective for treating chronic soft tissue wounds. A second objective was to assess the possible systemic cytotoxicity of dissolved borate ions and other materials released from implanted borate glass microfibers. Cytotoxicity was assessed via histological evaluation of kidney tissue collected from animals 4 weeks after subcutaneously implanting high amounts of the borate glass microfibers. The evaluation of the kidney tissue from these animals showed no evidence of chronic histopathological changes in the kidney. The overall results indicate the borate glass microfibers are safe and effective for soft tissue applications. PMID:24677635

  11. Spectroscopic analysis of Ho3+ transitions in different modifier oxide based lithium-fluoro-borate glasses

    NASA Astrophysics Data System (ADS)

    Balakrishna, A.; Rajesh, D.; Ratnakaram, Y. C.

    2014-10-01

    In recent investigations it was observed that the presence of different structural groups in borate glasses was favorable for spectroscopic investigations of rare earth doped borate glasses. Consequent to these observations, the heavy metal fluoride glasses doped with Ho3+ ions received much attention due to their wide transparency in the ultraviolet to infrared region. Keeping these observations in view, the present paper makes an attempt to present spectral investigations of Ho3+ doped lithium-fluoro-borate glasses of the compositions Li2B4O7-BaF2-NaF-MO (where M=Mg, Ca, Cd and Pb), Li2B4O7-BaF2-NaF-MgO-CaO and Li2B4O7-BaF2-NaF-CdO-PbO. These rare earth doped glasses were synthesized by melt quenching technique and an investigation was carried out to observe the structural (SEM and FT-IR) and optical (absorption and luminescence) properties. The paper also aims at the determination of three phenomenological Judd-Ofelt intensity parameters and special attention was paid to study the emission properties by employing the J-O intensity parameters. The visible emission spectra of Ho3+ ion in different lithium-fluoro-borate glasses were recorded by exciting the samples at 409 nm. The results revealed that among all the glass matrices, cadmium glass matrix have shown higher stimulated emission cross-section, which indicates that this is a good lasing material at this wavelength and highly useful for laser excitation.

  12. CADMIUM-RARE EARTH BORATE GLASS AS REACTOR CONTROL MATERIAL

    DOEpatents

    Ploetz, G.L.; Ray, W.E.

    1958-11-01

    A reactor control rod fabricated from a cadmiumrare earth-borate glass is presented. The rare earth component of this glass is selected from among those rare earths having large neutron capture cross sections, such as samarium, gadolinium or europium. Partlcles of this glass are then dispersed in a metal matrix by standard powder metallurgy techniques.

  13. Impact of vanadium ions in barium borate glass

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; Hammad, Ahmed H.

    2015-02-01

    Combined optical and infrared spectral measurements of prepared barium borate glasses containing different concentrations of V2O5 were carried out. Vanadium containing glasses exhibit extended UV-visible (UV/Vis.) bands when compared with base binary borate glass. UV/Vis. spectrum shows the presence of an unsymmetrical strong UV broad band centered at 214 nm attributed to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of such glass. The calculated direct and indirect optical band gaps are found to decrease with increasing the vanadium content (2.9:137 for indirect and 3.99:2.01 for direct transition). This change was discussed in terms of structural changes in the glass network. Infrared absorption spectra of the glasses reveal the appearance of both triangular and tetrahedral borate units. Electron spin resonance analyses indicate the presence of unpaired species in sufficient quantity to be identified and to confirm the spectral data.

  14. Interpretation of the IR spectra of alkali borate glasses

    SciTech Connect

    Chekhovskii, V.G.

    1985-11-01

    This paper describes methods of interpretation of the IR spectra of alkali borate glasses. In view of the difficulties which are encountered in a strict interpretation of the IR spectra of crystalline oxygen-containing compounds with complex anions, semiempirical methods of interpretation are commonly used. The existence of glasses of groups with an atomic (ionic) arrangement close to that in the crystalline compounds makes it possible to a certain extent to use the spectra of crystalline compounds in the interpretation of the IR spectra of glasses. The alkali borate glass systems were chosen for this study because the information on their structure is the most detailed by comparison with other borate glasses. IR spectrospcopy showed that the spectral regions in which fundamental asymmetrical stretching vibrations in BO/sub 3/ and BO/sub 4/ polyhedra occur, in most cases, are fairly clearly defined independently of the combined or separate presence of these polyhedra. It is proposed that the bands in the IR spectra of sodium and lithium borate glasses be assigned to vibrations mostly localized on specific fragments of polyborate groups present in the glasses. The data from IR spectroscopy confirms that tetraborate groups are present in lithium borate glasses.

  15. Synthesis and characterization of rare-earth doped SrBi{sub 2}Nb{sub 2}O{sub 9} phase in lithium borate based nanocrystallized glasses

    SciTech Connect

    Harihara Venkataraman, B.; Fujiwara, Takumi; Komatsu, Takayuki

    2009-06-15

    Glass composites comprising of un-doped and samarium-doped SrBi{sub 2}Nb{sub 2}O{sub 9} nanocrystallites are fabricated in the glass system 16.66SrO-16.66[(1-x)Bi{sub 2}O{sub 3}-xSm{sub 2}O{sub 3}]-16.66Nb{sub 2}O{sub 5}-50Li{sub 2}B{sub 4}O{sub 7} (0<=x<=0.5, in mol%) via the melt quenching technique. The glassy nature of the as-quenched samples is established by differential thermal analyses. Transmission electron microscopic studies reveal the presence of about 15 nm sized spherical crystallites of the fluorite-like SrBi{sub 1.9}Sm{sub 0.1}Nb{sub 2}O{sub 9} phase in the samples heat treated at 530 deg. C. The formation of layered perovskite-type un-doped and samarium-doped SrBi{sub 2}Nb{sub 2}O{sub 9} nanocrystallites with an orthorhombic structure through the intermediate fluorite phase is confirmed by X-ray powder diffraction and micro-Raman spectroscopic studies. The influence of samarium doping on the lattice parameters, lattice distortions, and the Raman peak positions of SrBi{sub 2}Nb{sub 2}O{sub 9} perovskite phase is clarified. The dielectric constants of the perovskite SrBi{sub 2}Nb{sub 2}O{sub 9} and SrBi{sub 1.9}Sm{sub 0.1}Nb{sub 2}O{sub 9} nanocrystals are relatively larger than those of the corresponding fluorite-like phase and the precursor glass. - Graphical Abstract: This figure shows the XRD patterns at room temperature for the as-quenched and heat treated samples in Sm{sub 2}O{sub 3}-doped (x=0.1) glass. Based on these results, it is concluded that the formation of samarium-doped perovskite SBN phase takes place via an intermediate fluorite-like phase in the crystallization of this glass.

  16. [Effect of Eu ions on the Ag nanoparticles precipitation and their optical properties in borate glasses].

    PubMed

    Liu, Zhi-liang; Jiao, Qing; Qiu, Jian-bei

    2014-08-01

    Eu-Ag co-doped borate glasses were prepared by the high temperature solid method in the present work. Absorption and emission spectra were employed to investigate the precipitation of Ag nanoparticles, which is influenced by the network form B2O3 and the co-doped Eu ions. It was found in the absorption spectra of Eu-Ag co-doped sample that a broad band centered at about 410 nm emerged and their intensity decreased with the increase in the BZ 03 concentration. Meanwhile, under the excitation of 340 nm, a broad emission band was observed in the wavelength range of 350-600 nm, which belongs to the blue-green light of Ag aggregates. The intensity of the Ag aggregates presented an increasing tendency with the increase in the B2O3 contents. The weak characteristic emission of Ag aggregates and Eu3+ was observed respectively in their singly doped samples. It is concluded that both their emissions get significant enhancement when Eu ions and Ag ions are used for co-doping the sample. In addition, the increased absorption of Ag nanoparticles was detected with the increase in the Eu ions concentration. Herein, the mechanism behind Eu3+ contribution to the precipitation of Ag nanoparticles is discussed in detail. The luminescence properties of borate glasses can be controlled by the microstructure of the borate glasses. Therefore, the white emission can be realized by the adjustment of glass structure and Eu ions concentration, owing to the red light from Eu3+ : (5)D0-->(7)Fj electronic transition and the blue-green light form the broad emission of Ag aggregates. The borate glasses are expected to be the candidates for the light-emission diode (LED) luminescent materials. PMID:25474935

  17. [Effect of Eu ions on the Ag nanoparticles precipitation and their optical properties in borate glasses].

    PubMed

    Liu, Zhi-liang; Jiao, Qing; Qiu, Jian-bei

    2014-08-01

    Eu-Ag co-doped borate glasses were prepared by the high temperature solid method in the present work. Absorption and emission spectra were employed to investigate the precipitation of Ag nanoparticles, which is influenced by the network form B2O3 and the co-doped Eu ions. It was found in the absorption spectra of Eu-Ag co-doped sample that a broad band centered at about 410 nm emerged and their intensity decreased with the increase in the BZ 03 concentration. Meanwhile, under the excitation of 340 nm, a broad emission band was observed in the wavelength range of 350-600 nm, which belongs to the blue-green light of Ag aggregates. The intensity of the Ag aggregates presented an increasing tendency with the increase in the B2O3 contents. The weak characteristic emission of Ag aggregates and Eu3+ was observed respectively in their singly doped samples. It is concluded that both their emissions get significant enhancement when Eu ions and Ag ions are used for co-doping the sample. In addition, the increased absorption of Ag nanoparticles was detected with the increase in the Eu ions concentration. Herein, the mechanism behind Eu3+ contribution to the precipitation of Ag nanoparticles is discussed in detail. The luminescence properties of borate glasses can be controlled by the microstructure of the borate glasses. Therefore, the white emission can be realized by the adjustment of glass structure and Eu ions concentration, owing to the red light from Eu3+ : (5)D0-->(7)Fj electronic transition and the blue-green light form the broad emission of Ag aggregates. The borate glasses are expected to be the candidates for the light-emission diode (LED) luminescent materials. PMID:25508714

  18. Topological phases in Ba-Borate glasses

    NASA Astrophysics Data System (ADS)

    Holbrook, Chad; Czaja, Andrew; Boolchand, Punit

    2015-03-01

    Twelve compositions in the (BaO)x(B2O3)100-x pseudo binary, in the 15% Borates2. Modes near 808 cm-1, 770 cm-1, 740 cm-1 and 705 cm-1 are observed, and identified with breathing modes of pure and mixed rings from characteristic structural groupings2. These preliminary results suggest that glasses at x <24% are in the stressed-rigid phase, in the 24% 30% in the flexible phase. Supported by NSF Grant DMR 08-53957.

  19. Spectroscopic studies of lead halo borate glasses

    NASA Astrophysics Data System (ADS)

    Sekhar, K. Chandra; Hameed, Abdul; Chary, M. Narasimha; Shareefuddin, Md.

    2015-06-01

    Glasses in the system xPbF2-(30-x) PbO-69B2O3-1CuO (x=5, 10, 15, 20, & 25 mole %) were prepared by melt quenching method and they are characterized by XRD to confirm the glassy nature. Electron Paramagnetic Resonance (EPR) studies at room temperature in the X-band frequencies and FTIR studies on prepared glass systems were reported. The non-linear variation of spin-Hamiltonian parameters with PbF2 content indicated the change in the ligand field strength around Cu2+ ions in the host glass. The ground state of Cu2+ ions in the glass is designated as dx2-y2 orbital (2B1g) while the observed symmetry around it is tetragonally distorted octahedral. The molecular orbital coefficients α2, β2 and β12 are evaluated for Cu2+ doped samples. From the FTIR studies it was observed that the glass made up of BO3 and BO4 units.

  20. Coordination and valence state of transition metal ions in alkali-borate glasses

    NASA Astrophysics Data System (ADS)

    Terczy?ska-Madej, A.; Cholewa-Kowalska, K.; ??czka, M.

    2011-10-01

    Borate glasses of the 20R 2O80B 2O 3 type, where R = Li, Na and K, were colored by doping with transition metal ions (Co, Ni, Cr and Mn). The glasses were obtained by melting at the temperature of 1150 C. For these glasses optical absorption in UV-VIS-NIR range were recorded. Analysis of the spectra allows to be determined the coordination and oxidation states of the doping transition metal ions. Changes of their coordination or oxidation are presented as a function of the optical basicity ? after Duffy. Cobalt and nickel are present in examined borate glasses as divalent ions (Co 2+, Ni 2+) in octahedral coordination mainly, but the tetrahedral coordination state of cobalt is also possible. Chromium and manganese are present in the borate glasses in various oxidation state, though Cr 3+ and Mn 3+ ions in the octahedral coordination are probably dominant. A decrease of the electronegativity of the modifiers (Li ? Na ? K) and an increase of the glass matrix basicity cause a shift of the oxidation/reduction equilibrium towards higher valences of the transition metals (Cr 6+, Mn 3+).

  1. Barium-borate-flyash glasses: As radiation shielding materials

    NASA Astrophysics Data System (ADS)

    Singh, Sukhpal; Kumar, Ashok; Singh, Devinder; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The attenuation coefficients of barium-borate-flyash glasses have been measured for ?-ray photon energies of 356, 662, 1173 and 1332 keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3. Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free path (mfp), effective atomic number and electron density. Good agreements have been observed between experimental and theoretical values of these parameters. From the studies of the obtained results it is reported here that from the shielding point of view the barium-borate-flyash glasses are better shields to ?-radiations in comparison to the standard radiation shielding concretes and also to the ordinary barium-borate glasses.

  2. A crystallographic guide to the structure of borate glasses

    SciTech Connect

    Wright, A.C.; Vedishcheva, N.M.; Shakhmatkin, B.A.

    1997-12-31

    Borate glasses are an enigma in that there is now increasing evidence that their structures are dominated by superstructural units, which comprise well defined arrangements of the basic BO{sub 3} and BO{sub 4} structural units, with no internal degrees of freedom in the form of variable bond or torsion angles. In the present paper, it is shown that considerable insight into the structure of borate glasses can be gained from a study of the corresponding crystalline polymorphs. A simple, model is proposed to predict the fraction, x{sub 4}, of 4-fold coordinated boron atoms in vitreous borate networks and the topological criteria for the formation of such networks are discussed, taking into account the degrees of freedom necessary for conventional glass formation.

  3. Thermographic investigation of luminescent barium borate glasses for white-LED applications

    NASA Astrophysics Data System (ADS)

    Wagner, Florian; Nolte, Peter W.; Steudel, Franziska; Schweizer, Stefan

    2015-05-01

    A method to analyze the heat generation in luminescent barium borate glasses under continuous optical excitation is presented. The heat development is monitored by infrared thermography. Experimental surface temperature data are used as input for the differential heat equation to evaluate the volumetric heat rate from the spatial and temporal development of the temperature distribution. Having determined the volumetric heat rate in the glass, the heat generation under optical excitation can be estimated without further knowledge of optical parameters. Experiments on barium borate glasses with different doping levels are performed. For comparison, the heat generation is also estimated on the basis of optical parameters only to confirm the accuracy and validity of the presented method via infrared thermography. The experimentally determined total heat generation is in good agreement with those calculated from optical properties.

  4. Strontium borate glass: potential biomaterial for bone regeneration

    PubMed Central

    Pan, H. B.; Zhao, X. L.; Zhang, X.; Zhang, K. B.; Li, L. C.; Li, Z. Y.; Lam, W. M.; Lu, W. W.; Wang, D. P.; Huang, W. H.; Lin, K. L.; Chang, J.

    2010-01-01

    Boron plays important roles in many life processes including embryogenesis, bone growth and maintenance, immune function and psychomotor skills. Thus, the delivery of boron by the degradation of borate glass is of special interest in biomedical applications. However, the cytotoxicity of borate glass which arises with the rapid release of boron has to be carefully considered. In this study, it was found that the incorporation of strontium into borate glass can not only moderate the rapid release of boron, but also induce the adhesion of osteoblast-like cells, SaOS-2, thus significantly increasing the cyto-compatibility of borate glass. The formation of multilayers of apatite with porous structure indicates that complete degradation is optimistic, and the spread of SaOS-2 covered by apatite to form a sandwich structure may induce bone-like tissue formation at earlier stages. Therefore, such novel strontium-incorporated borosilicate may act as a new generation of biomaterial for bone regeneration, which not only renders boron as a nutritious element for bone health, but also delivers strontium to stimulate formation of new bones. PMID:20031984

  5. High-temperature relaxation spectra of borate glasses

    SciTech Connect

    Lomovskoi, V.A.; Bartenev, G.M.

    1993-07-01

    A critical analysis of a method for calculating the spectrum characteristics of mechanical relaxation in glass melts is given. The analysis of changes in the spectrum characteristics (in the Kohlrausch function approximation) for B{sub 2}O{sub 3} and sodium borate glasses within a broad temperature and frequency range allows us to ascertain the specific features of these changes due to structural factors.

  6. Impact of vanadium ions in barium borate glass.

    PubMed

    Abdelghany, A M; Hammad, Ahmed H

    2015-02-25

    Combined optical and infrared spectral measurements of prepared barium borate glasses containing different concentrations of V2O5 were carried out. Vanadium containing glasses exhibit extended UV-visible (UV/Vis.) bands when compared with base binary borate glass. UV/Vis. spectrum shows the presence of an unsymmetrical strong UV broad band centered at 214 nm attributed to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of such glass. The calculated direct and indirect optical band gaps are found to decrease with increasing the vanadium content (2.9:137 for indirect and 3.99:2.01 for direct transition). This change was discussed in terms of structural changes in the glass network. Infrared absorption spectra of the glasses reveal the appearance of both triangular and tetrahedral borate units. Electron spin resonance analyses indicate the presence of unpaired species in sufficient quantity to be identified and to confirm the spectral data. PMID:25194319

  7. The leaching behavior of borate waste glass SL-1

    SciTech Connect

    Sheng, J.; Luo, S.; Tang, B.

    1999-11-01

    Vitrification is an attractive approach for treatment of the borate waste from nuclear power plants. SL-1 glass is a suitable borosilicate glass form to solidify the borate waste containing relatively high quantities of B and Na. The leaching behavior of SL-1 glass in deionized water has been investigated. Compared to the HLW-glass, the network structure of SL-1 glass is weak. It was found that the ion-exchange reactions dominated the glass corrosion process with water in low temperature leading conditions. The ion-exchange and network hydrolysis reactions together controlled the glass dissolution in high temperature leaching conditions. There was a peak in leach rate at about 70 C and a valley at about 100 C. The surface layer thickness was about 25 {micro}m. Na was almost totally depleted in the surface layer. At low temperature, the glass corrosion increases with leaching time. The glass corrosion remains about constant with leaching time at 90 C. The surface layer formed at 90 C is protective, which is less porous than the surface layer formed at 40 and 70 C.

  8. The leaching behavior of borate waste glass SL-1

    SciTech Connect

    Sheng, J. ); Luo, S.; Tang, B. )

    1999-01-01

    Vitrification is an attractive approach for treatment of the borate waste from nuclear power plants. SL-1 glass is a suitable borosilicate glass form to solidify the borate waste containing relatively high quantities of B and Na. The leaching behavior of SL-1 glass in deionized water has been investigated. Compared to the HLW-glass, the network structure of SL-1 glass is weak. It was found that the ion-exchange reactions dominated the glass corrosion process with water in low temperature leading conditions. The ion-exchange and network hydrolysis reactions together controlled the glass dissolution in high temperature leaching conditions. There was a peak in leach rate at about 70 C and a valley at about 100 C. The surface layer thickness was about 25 [micro]m. Na was almost totally depleted in the surface layer. At low temperature, the glass corrosion increases with leaching time. The glass corrosion remains about constant with leaching time at 90 C. The surface layer formed at 90 C is protective, which is less porous than the surface layer formed at 40 and 70 C.

  9. FTIR of binary lead borate glass: Structural investigation

    NASA Astrophysics Data System (ADS)

    Othman, H. A.; Elkholy, H. S.; Hager, I. Z.

    2016-02-01

    The glass samples were prepared according to the following formula: (100-x) B2O3 - x PbO, where x = 20-80 mol% by melt quenching method. The density of the prepared samples was measured and molar volume was calculated. IR spectra were measured for the prepared samples to investigate the glass structure. The IR spectra were deconvoluted using curves of Gaussian shape at approximately the same frequencies. The deconvoluted data were used to study the effect of PbO content on all the structural borate groups. Some structural parameters such as density, packing density, bond length and bond force constant were theoretically calculated and were compared to the obtained experimental results. Deviation between the experimental and theoretically calculated parameters reflects the dual role of PbO content on the network of borate glass.

  10. Crystal nucleation in lithium borate glass

    NASA Technical Reports Server (NTRS)

    Smith, Gary L.; Neilson, George F.; Weinberg, Michael C.

    1988-01-01

    Crystal nucleation measurements were made on three lithium borate compositions in the vicinity of Li2O-2Br2O3. All nucleation measurements were performed at 500 C. Certain aspects of the nucleation behavior indicated (tentatively) that it proceeded by a homogeneous mechanism. The steady state nucleation rate was observed to have the largest value when the Li2O concentration was slightly in excess of the diborate composition. The change in nucleation rate with composition is controlled by the variation of viscosity as well as the change in free energy with composition. The variation of nucleation rate is explained qualitatively in these terms.

  11. Optical properties of down-shifting barium borate glass for CdTe solar cells

    NASA Astrophysics Data System (ADS)

    Loos, Sebastian; Steudel, Franziska; Ahrens, Bernd; Schweizer, Stefan

    2015-03-01

    CdTe thin film solar cells have a poor response in the ultraviolet and blue spectral range, mainly due to absorption and thermalization losses in the CdS buffer layer. To overcome this efficiency drop in the short wavelength range trivalent rare-earth doped barium borate glass is investigated for its potential as frequency down-shifting cover glass on top of the cell. The glass is doped with either Tb3+ or Eu3+ up to a level of 2.5 at.% leading to strong absorption in the ultraviolet/blue spectral range. Tb3+ shows intense emission bands in the green spectral range while Eu3+ emits in the orange/red spectral range. Based on rare-earth absorption and luminescence quantum efficiency the possible gain in short-circuit current density is calculated.

  12. Laser spectroscopy of Nd 3+ and Dy 3+ ions in lead borate glasses

    NASA Astrophysics Data System (ADS)

    Pisarska, Joanna; Pisarski, Wojciech A.; Ryba-Romanowski, Witold

    2010-07-01

    The spectroscopic and laser properties of Nd 3+ and Dy 3+ ions in lead borate glass were studied. Luminescence spectra recorded in the near-infrared and visible ranges correspond to 4F 3/2- 4I J/2 ( J=9, 11, 13) transitions of Nd 3+ and 4F 9/2- 6H J/2 ( J=11, 13, 15) transitions of Dy 3+, respectively. Luminescence decay curves were analyzed as a function of activator concentration. Luminescence quenching is observed, which is due to Ln-Ln interaction increasing. Several spectroscopic parameters relevant to laser potential of Ln 3+ ions (Ln=Nd, Dy) in lead borate glass were determined. The relatively large values of the quantum efficiency and the room-temperature emission cross-section for the 4F 3/2- 4I 11/2 transition of Nd 3+ at 1061 nm and the 4F 9/2- 6H 13/2 transition of Dy 3+ at 573 nm imply that Ln-doped lead borate glasses can be considered as promising solid-state materials for laser applications.

  13. Effect of copper oxide on structure and physical properties of lithium lead borate glasses

    NASA Astrophysics Data System (ADS)

    Kashif, I.; Ratep, A.

    2015-09-01

    Copper-doped Lead lithium borate glass samples with the composition of (35- x) Pb3O4- xCuO-65Li2B4O7, where x = 5, 10, 15 or 20 mol%, have been prepared by melt quenching technique. Glass-forming ability, density, electrical conductivity, magnetic susceptibility and structural properties of lead lithium borate glasses have been investigated. IR spectroscopic data show that the copper ions play the role of glass modifier. Addition of CuO influences BO3 ↔ BO4 conversion. Density is expressed in terms of the structural modifications that take place in glass matrix. The increase in Tg reflects an increase in bond strength, and samples obtain more rigid glass structure. Electrical conductivity and magnetic susceptibility χ data show a variable behavior with the increase in the copper content in two valance states Cu+ and Cu+2. In addition, optical properties depend on the change of the role of copper ions in the samples' structure. Optical energy band gap E opt and Urbach energy E tail are determined. The increase in E opt and UV cutoff with an increase in CuO content is due to the decrease in non-bridging oxygen concentration. The decrease in E tail at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. These samples are suitable for the green light longpass filters.

  14. XRD and FTIR studies the effect of heat treatment and doping the transition metal oxide on LiNbO3 and LiNb3O8 nano-crystallite phases in lithium borate glass system

    NASA Astrophysics Data System (ADS)

    Kashif, Ismail; Soliman, Ashia A.; Sakr, Elham M.; Ratep, Asmaa

    2013-09-01

    Glasses of various compositions in the system 90 Li2B4O7sbnd 10 Nb2O5 mixed with T.M ions (where T.M is the transition metal) were prepared by quenching technique. Heat-treatment of the parent glasses was performed at 540, 570 and 620 C, for 5 and 16 h. The glass structure evolution during the controlled crystallization was examined by XRD and FT-IR spectroscopy analysis. The crystalline phases present in the glass ceramics were identified via X-ray diffraction as a function of heat treatment. The FT-IR data propose for these glasses and heat-treated glass network structures mainly built by: di-, tri-, tetra-, penta-and ortho-borate groups. It was found that the quantitative evolution of these various borate species in the glass structures is influenced by the transition metal. A detailed discussion relating to the N4 evolution with the T.M content was made.

  15. XRD and FTIR studies the effect of heat treatment and doping the transition metal oxide on LiNbO3 and LiNb3O8 nano-crystallite phases in lithium borate glass system.

    PubMed

    Kashif, Ismail; Soliman, Ashia A; Sakr, Elham M; Ratep, Asmaa

    2013-09-01

    Glasses of various compositions in the system 90 Li2B4O7-10 Nb2O5 mixed with T.M ions (where T.M is the transition metal) were prepared by quenching technique. Heat-treatment of the parent glasses was performed at 540, 570 and 620 °C, for 5 and 16 h. The glass structure evolution during the controlled crystallization was examined by XRD and FT-IR spectroscopy analysis. The crystalline phases present in the glass ceramics were identified via X-ray diffraction as a function of heat treatment. The FT-IR data propose for these glasses and heat-treated glass network structures mainly built by: di-, tri-, tetra-, penta-and ortho-borate groups. It was found that the quantitative evolution of these various borate species in the glass structures is influenced by the transition metal. A detailed discussion relating to the N4 evolution with the T.M content was made. PMID:23708372

  16. Photoluminescence of a Te4+ center in zinc borate glass.

    PubMed

    Masai, Hirokazu; Yamada, Yasuhiro; Okumura, Shun; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-10-01

    Photoluminescent (PL) properties related to Te(4+) species in zinc borate glasses are examined. Broad emission was observed by the excitation of the PL excitation peak of Te(4+) present at the optical absorption edge. The emission intensity of Te(4+) in 5TeO(2)-50ZnO-45B(2)O(3) glass was thermally quenched in a temperature region over 100 K, suggesting that concentration quenching preferentially occurred. The lifetime of the emission was approximately 2.5 μs, which is characteristic of relaxation from the triplet excitation state of an ns(2)-type center. PMID:24081051

  17. Third order nonlinear optical properties of bismuth zinc borate glasses

    SciTech Connect

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V.; Kuladeep, R.; Narayana Rao, D.

    2013-12-28

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi{sub 2}O{sub 3}-30ZnO-(70-x) B{sub 2}O{sub 3} (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σ{sub e}) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

  18. Raman and Infrared Spectroscopy of Yttrium Aluminum Borate Glasses and Glass-ceramics

    NASA Technical Reports Server (NTRS)

    Bradley, J.; Brooks, M.; Crenshaw, T.; Morris, A.; Chattopadhyay, K.; Morgan, S.

    1998-01-01

    Raman spectra of glasses and glass-ceramics in the Y2O3-Al2O3-B2O3 system are reported. Glasses with B2O3 contents ranging from 40 to 60 mole percent were prepared by melting 20 g of the appropriate oxide or carbonate powders in alumina crucibles at 1400 C for 45 minutes. Subsequent heat treatments of the glasses at temperatures ranging from 600 to 800 C were performed in order to induce nucleation and crystallization. It was found that Na2CO3 added to the melt served as a nucleating agent and resulted in uniform bulk crystallization. The Raman spectra of the glasses are interpreted primarily in terms of vibrations of boron - oxygen structural groups. Comparison of the Raman spectra of the glass-ceramic samples with spectra of aluminate and borate crystalline materials reveal that these glasses crystallize primarily as yttrium aluminum borate, YAl3(BO3)4.

  19. Optical and FT Infrared spectral studies of vanadium ions in cadmium borate glass and effects of gamma irradiation.

    PubMed

    AbdelAziz, T D; EzzElDin, F M; El Batal, H A; Abdelghany, A M

    2014-10-15

    Combined optical and infrared absorption spectra of V2O5-doped cadmium borate glasses were investigated before and after gamma irradiation with a dose of 8 Mrad (=8×10(4) Gy). The undoped base cadmium borate glass reveals a spectrum consisting of strong charge transfer UV absorption bands which are related to the presence of unavoidable contaminated trace iron impurities (mainly Fe(3+)). The V2O5-doped glasses reveal an extra band at 380nm and the high V2O5-content glass also shows a further band at about 420nm. The observed optical spectrum indicates the presence of vanadium ions mainly in the pentavalent state (d(0) configuration). The surplus band at 420nm shows that some trivalent vanadium ions are identified at high V2O5 content. The optical spectra of the glasses after gamma irradiation show small decrease of the intensity of the UV absorption which are interpreted by assuming the transformation of some Fe(3+) ions by photochemical reactions with the presence of high content (45mol%) of heavy massive CdO causing some shielding behavior. FT infrared absorption spectra of the glasses show vibrational bands due to collective presence of triangular and tetrahedral borate groups in their specific wavenumbers. The FTIR spectra are observed to be slightly affected by both the V2O5-dopants being present in modifying low percent or gamma irradiation due to the presence of high content heavy CdO. PMID:24840491

  20. Structure-property relations in lanthanide borate glasses

    NASA Technical Reports Server (NTRS)

    Chakraborty, I. N.; Day, D. E.; Lapp, J. C.; Shelby, J. E.

    1985-01-01

    Glass formation in the system Ln2O3-B2O3 (Ln = Nd, Sm) was studied. Glasses could be formed in the range from 0 to 28 mol pct rare-earth oxide (Ln2O3), but liquid immiscibility in these systems limits the range of homogeneous glasses to 0 to 1.5 and 25 to 28 mol pct Ln2O3. The infrared spectra indicate that the rare-earth-rich glasses are structurally similar to rare-earth metaborates (LnB3O6) which contain (B3O6)-infinity chains. The variation in density, transformation temperature, thermal expansion coefficient, and transformation-range viscosity of these glasses with the size of the rare-earth ion is discussed. Glasses near the metaborate composition have a transformation temperature of about 700 C, which is high for binary borate glasses. Glasses could not be formed in the systems Eu2O3-, Gd2O3-, Ho2O3-, and Er2O3-B2O3, even by quenching at 1300 C/s. The sudden lack of glass formation in the system Ln2O3-B2O3 with Ln(3+) ions smaller than Sm(3+) is explained on the basis of the size effect of the Ln(3+) ion on the stability of (B3O6)-infinity chains in these metaborates.

  1. Luminescence properties of Sm{sup 3+} impurities in strontium lithium bismuth borate glasses

    SciTech Connect

    Rajesh, D.; Ratnakaram, Y. C.; Seshadri, M.; Balakrishna, A.

    2012-06-05

    In the present work, different concentrations of Sm{sup 3+}-doped strontium lithium bismuth borate glasses (SLBiB) were prepared by melt quench technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction and SEM analysis. Using the J-O intensity parameters, emission and decay measurements various radiative properties are studied. The nature of decay curves of {sup 4}G{sub 5/2} level for different Sm{sup 3+} ion concentrations in SLBiB glasses has been analyzed. The intensities of observed emission peaks and measured lifetimes decrease with the increase of Sm{sup 3+} ion concentration which may be due to energy transfer between excited Sm{sup 3+} ions through cross-relaxations and resonant energy channels.

  2. Relationship between Eu{sup 3+} reduction and glass polymeric structure in Al{sub 2}O{sub 3}-modified borate glasses under air atmosphere

    SciTech Connect

    Jiao, Qing; Yu, Xue; Xu, Xuhui; Zhou, Dacheng; Qiu, Jianbei

    2013-06-15

    The reduction of Eu{sup 3+} to Eu{sup 2+} is realized efficiently in Eu{sub 2}O{sub 3}-doped borate glasses prepared under air condition by melting-quenching method. Luminescent spectra show an increasing tendency of Eu{sup 2+} emission with increasing Al{sub 2}O{sub 3} concentration in B{sub 2}O{sub 3}–Na{sub 2}O glasses. It is interesting that significant enhancement appeared of Eu{sup 2+} luminescence in the Al{sub 2}O{sub 3}-rich sample comparing to the samples of Al{sub 2}O{sub 3} less than 6 mol%. FTIR and Raman scattering measurements indicated that some new vibration modes assigned to the low-polymerized structure groups decomposed from the slight Al{sub 2}O{sub 3} dopant samples. These results demonstrated that the polymerization of the glass structure decreased with increasing incorporation of Al{sub 2}O{sub 3} into the borate glasses, linking to the efficiency of Eu{sup 3+} self-reduction in air at high temperature. - graphical abstract: A novel europium valence reduction phenomenon occurred in Al{sub 2}O{sub 3} modified borate glasses, FTIR and Raman measurements revealed that high polymeric groups were destroyed to low polymery structures with Al{sub 2}O{sub 3} addition. - Highlights: • The efficient reduction of Eu{sup 3+} to Eu{sup 2+} is observed in the B{sub 2}O{sub 3}–Na{sub 2}O glasses. • Eu{sup 2+} luminescence is significant enhanced in the Al{sub 2}O{sub 3}-rich glasses. • The introduction of Al{sub 2}O{sub 3} changed the network structure of the borate glasses. • High polymeric borate groups in the glass matrix may be destroyed to the lower ones.

  3. Synthesis and studies on microhardness of alkali zinc borate glasses

    SciTech Connect

    Subhashini, Bhattacharya, Soumalya Shashikala, H. D. Udayashankar, N. K.

    2014-04-24

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi{sub 2}O+yNa{sub 2}O+80B{sub 2}O{sub 3} (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li{sub 2}O and Na{sub 2}O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO{sub 4/2}){sup −} into (BO{sub 3/2}){sup −}. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  4. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

    PubMed

    Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. PMID:26117744

  5. Molecular dynamics simulation of alkali borate glass using coordination dependent potential

    SciTech Connect

    Park, B.; Cormack, A.N.

    1997-12-31

    The structure of sodium borate glass was investigated by molecular dynamics simulation using coordination dependent potential model. The simulated alkali borate glass consists of basic units, BO{sub 3} triangle, BO{sub 4} tetrahedra and structural groups such as boroxol ring and triborate units. The coordination of boron is converted from 3 to 4 by adding alkali oxide.

  6. Borates

    USGS Publications Warehouse

    Crangle, R.D., Jr.

    2013-01-01

    Four minerals represent 90 percent of the borates used by industry worldwide — the sodium borates (tincal and kernite), calcium borate (colemanite) and the sodium-calcium borate (ulexite). Borax is a white crystalline substance, chemically known as sodium tetraborate decahydrate, and is found naturally as the mineral tincal. Boric acid is a colorless crystalline solid sold in technical, national formulary and special quality grades as granules or powder and marketed most often as anhydrous boric acid. Deposits of borates are associated with volcanic activity and arid climates, with the largest economically viable deposits located in the Mojave Desert of the United States near Boron, CA, the Alpide belt in southern Asia and the Andean belt of South America.

  7. Ultrasonic relaxations, anharmonicity, and fragility in lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Carini, Giovanni; Carini, Giuseppe; D'Angelo, Giovanna; Tripodo, Gaspare; Bartolotta, Antonio; Salvato, Gabriele

    2005-07-01

    The attenuation and velocity of ultrasonic waves of frequencies in the range of 10to70MHz have been measured in (Li2O)x(B2O3)1-x borate glasses as a function of temperature between 1.5 and 300K . Two distinct features characterize the attenuation behavior: (i) a plateau at temperatures below 10K , (ii) a broad high-temperature peak. The former feature is interpreted in terms of the phonon-assisted relaxation of two level systems and the latter by assuming the existence of a distribution of thermally activated relaxing centers. The spectral density of two-level systems results to be independent on the alkali oxide content, while the density of relaxing particles decreases with increasing lithium ion concentration supporting their association to the triangular BO?3 units building up the borate skeleton ( O?=oxygen atom bridging between two network-forming ions, i.e., boron ions). The comparison between the number densities of two-level systems and of relaxing particles indicates that only a small fraction of the locally mobile defects are subjected to tunneling motions. At temperatures below 100K the sound velocity is mainly governed by the relaxation contribution, while above 100K it is regulated by the vibrational anharmonicity and shows a nearly linear temperature dependence, whose slope strongly depends on the concentration of network modifier ions ( Li+ ions). The determination of the average thermal Grneisen parameters permits us also to disclose the existence of a distinct correlation between anharmonicity and fragility of lithium borate glasses: a growing fragility is predictive of an increasing anharmonicity.

  8. Ytterbium-doped borate fluoride laser crystals and lasers

    DOEpatents

    Schaffers, K.I.; DeLoach, L.D.; Payne, S.A.; Keszler, D.A.

    1997-10-14

    A new class of solid state laser crystals and lasers are formed from Yb-doped borate fluoride host crystals. The general formula for the host crystals is MM{prime}(BO{sub 3})F, where M, M{prime} are monovalent, divalent aria trivalent metal cations. A particular embodiment of the invention is Yb-doped BaCaBO{sub 3}F (Yb:BCBF). BCBF and some of the related derivative crystals are capable of nonlinear frequency conversion, whereby the fundamental of the laser is converted to a longer or shorter wavelength. In this way, these new crystals can simultaneously serve as self-frequency doubling crystals and laser materials within the laser resonator. 6 figs.

  9. Ytterbium-doped borate fluoride laser crystals and lasers

    DOEpatents

    Schaffers, Kathleen I.; DeLoach, Laura D.; Payne, Stephen A.; Keszler, Douglas A.

    1997-01-01

    A new class of solid state laser crystals and lasers are formed from Yb-doped borate fluoride host crystals. The general formula for the host crystals is MM'(BO.sub.3)F, where M, M' are monovalent, divalent aria trivalent metal cations. A particular embodiment of the invention is Yb-doped BaCaBO.sub.3 F (Yb:BCBF). BCBF and some of the related derivative crystals are capable of nonlinear frequency conversion, whereby the fundamental of the laser is converted to a longer or shorter wavelength. In this way, these new crystals can simultaneously serve as self-frequency doubling crystals and laser materials within the laser resonator.

  10. Narrow Energy Gap between Triplet and Singlet Excited States of Sn2+ in Borate Glass

    PubMed Central

    Masai, Hirokazu; Yamada, Yasuhiro; Suzuki, Yuto; Teramura, Kentaro; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-01-01

    Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns2-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn2+-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors. PMID:24345869

  11. Narrow energy gap between triplet and singlet excited states of Sn2+ in borate glass.

    PubMed

    Masai, Hirokazu; Yamada, Yasuhiro; Suzuki, Yuto; Teramura, Kentaro; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-01-01

    Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns(2)-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn(2+)-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors. PMID:24345869

  12. Narrow Energy Gap between Triplet and Singlet Excited States of Sn2+ in Borate Glass

    NASA Astrophysics Data System (ADS)

    Masai, Hirokazu; Yamada, Yasuhiro; Suzuki, Yuto; Teramura, Kentaro; Kanemitsu, Yoshihiko; Yoko, Toshinobu

    2013-12-01

    Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and formability. However, photoluminescence dynamics of ns2-type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn2+-doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1-S0 transition and a slower T1-S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors.

  13. Interpretation of IR spectra for lithium and sodium borate glasses

    SciTech Connect

    Chekhovskii, V.G.

    1994-05-01

    In the boron-oxygen groupings of crystalline and vitreous borates, such as triborate, tetraborate, and pentaborate, where B{sup III}-O(B{sup III}) and B{sup III}-O(B{sup IV}) bonds are present at the same time, one may arbitrarily single out groups of atoms with such bonds, similar to pyroborate and chain metaborate groupings in terms of structure and in the predominant localization of vibrations. From an analysis of what is known about the origin of bands in the IR spectra of the glasses investigated over the entire range of their compositions, may attribute the 1150-1300 cm{sup -1} bands mainly to the stretching vibrations of atoms in groups with B{sup III}-O(B{sup III}) bonds and, in glasses low in B{sub 2}O{sub 3}, also in BO{sup 3-}{sub 3} groups; in the 1300-1500 cm{sup -1} range, this holds for groups with B{sup III}-O(B{sup IV}) and/or B{sup III}-O{sup -} bonds.

  14. Impact of Nd3+ ions on physical and optical properties of Lithium Magnesium Borate glass

    NASA Astrophysics Data System (ADS)

    Mhareb, M. H. A.; Hashim, S.; Ghoshal, S. K.; Alajerami, Y. S. M.; Saleh, M. A.; Dawaud, R. S.; Razak, N. A. B.; Azizan, S. A. B.

    2014-11-01

    Enhancing the up-conversion efficiency of borate glass via optimized doping of rare earth ions is an ever-ending quest in lasing glass. Neodymium (Nd3+) doped Lithium Magnesium Borate (LMB) glasses are prepared using the melt-quenching method. X-ray diffraction (XRD), Fourier transformed infrared (FTIR), UV-Vis-NIR absorption and Photoluminescence (PL) spectroscopic characterizations are made to examine the influence of Nd3+ concentration on physical properties and optical properties. Nd3+ contents dependent density, molar volume, refractive index, ion concentration, Polaron radius, inter nuclear distance, field strength, energy band gap and oscillator strength are calculated. XRD patterns confirm the amorphous nature of all glasses and the FTIR spectra reveal the presence of BO3 and BO4 functional groups. UV-Vis-IR spectra exhibit ten prominent bands centered at 871, 799, 741, 677, 625, 580, 522, 468, 426, 349 nm corresponding to the transitions from the ground state to 4F3/2, (4F5/2 + 2H9/2), (4F7/2 + 4S3/2), 4F9/2, 2H11/2, (4G5/2 + 2G7/2), (2K13/2 + 4G7/2 + 4G9/2), (2G9/2 + 2D3/2 + 2P3/2), (2P1/2 + 2D5/2), (4D3/2 + 4D5/2) excited states, respectively. A hyper-sensitive transition related to (4G5/2 + 2G7/2) level is evidenced at 580 nm. The room temperature up-conversion emission spectra at 800 nm excitation displays three peaks centered at 660, 610 and 540 nm. Glass with 0.5 mol% of Nd3+ showing an emission enhancement by a factor to two is attributed to the energy transfer between Mg2+ and Nd3+ ions. Our results suggest that these glasses can be nominated for solid state lasers and other photonic devices.

  15. Composition-structure-properties relationship of strontium borate glasses for medical applications.

    PubMed

    Hasan, Muhammad S; Werner-Zwanziger, Ulrike; Boyd, Daniel

    2015-07-01

    We have synthesized TiO2 doped strontium borate glasses, 70B2O3-(30-x)SrO-xTiO2 and 70B2 O3 -20SrO(10-x)Na2 O-xTiO2 . The composition dependence of glass structure, density, thermal properties, durability, and cytotoxicity of degradation products was studied. Digesting the glass in mineral acid and detecting the concentrations of various ions using an ICP provided the actual compositions that were 5-8% deviated from the theoretical values. The structure was investigated by means of (11)B magic angle spinning (MAS) NMR spectroscopy. DSC analyses provided the thermal properties and the degradation rates were measured by measuring the weight loss of glass disc-samples in phosphate buffered saline at 37°C in vitro. Finally, the MTT assay was used to analyze the cytotoxicity of the degradation products. The structural analysis revealed that replacing TiO2 for SrO or Na2 O increased the BO3/BO4 ratio suggesting the network-forming role of TiO2 . Thermal properties, density, and degradation rates also followed the structural changes. Varying SrO content predominantly controlled the degradation rates, which in turn controlled the ion release kinetics. A reasonable control (2-25% mass loss in 21 days) over mass loss was achieved in current study. Even though, very high concentrations (up to 5500 ppm B, and 1200 ppm Sr) of ions were released from the ternary glass compositions that saturated the degradation media in 7 days, the degradation products from ternary glass system was found noncytotoxic. However, quaternary glasses demonstrated negative affect on cell viability due to very high (7000 ppm) Na ion concentration. All the glasses investigated in current study are deemed fast degrading with further control over degradation rates, release kinetics desirable. PMID:25366812

  16. Antiquenching effect of modifying cations on samarium clustering: Physical, structural and luminescent behavior of heavy metal borate glass systems

    NASA Astrophysics Data System (ADS)

    Kaur, Simranpreet; Kaur, Parvinder; Pal Singh, Gurinder; Kumar, Sunil; Singh, D. P.

    2015-09-01

    In this paper an attempt has been made to correlate the structural modifications and luminescence efficiencies by changing the environment of the glass network by modifying oxides. Sm3+ doped lead borate (SPB) and lead cadmium alumino borate (SCPB) glasses have been fabricated by melt quench technique at high temperature. The glass samples are characterized by XRD, FTIR, optical absorptions, fluorescence and density measurements. The effect of Sm3+ ion and glass host interaction on the emission spectra has been discussed in the view of the ionicity and covalency of hosts. The ratio of the intensities of electric to magnetic dipole emissions are calculated by varying both the concentration of the Sm3+ ion and the composition of the glass matrix. The XRD profile of all the glasses confirms their amorphous nature and FTIR spectrum shows the presence of BO3 and BO4 groups. These glasses have shown strong absorption bands in the visible (VIS and NIR) region and emit strong orange red wavelengths when excited by ultraviolet light. The concentration quenching has been noticed and ascribed to energy transfer through cross-relaxation between Sm3+ ions. Shifting of UV absorption edge towards longer wavelength with addition of Sm2O3 concentration has been observed. Incorporation of Al2O3 and CdO in 2nd glass system is responsible for strong effect on luminescence of the present glass system. Based on these results, an attempt has been made to throw some light on the relationship between the structural modifications and luminescence efficiencies in two different glass hosts as a laser active medium in the visible region. Moreover the optical basicity values were theoretically determined along with covalent behavior of two glass systems.

  17. Effects of copper on the preparation and characterization of Na-Ca-P borate glasses

    NASA Astrophysics Data System (ADS)

    Shailajha, S.; Geetha, K.; Vasantharani, P.; Sheik Abdul Kadhar, S. P.

    2015-03-01

    Glasses in the system Na2O-CaO-B2O3-P2O5: CuO have been prepared by melt quenching at 1200 °C and rapidly cooling at room temperature. The structural, optical and thermal properties have been investigated using X-ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform infrared (FTIR) spectroscopy, high resolution scanning electron microscopy (HRSEM) with energy dispersive X-ray (EDX) spectroscopy and high resolution transmission electron microscope (HRTEM) with energy dispersive X-ray (EDAX). The amorphous and crystalline nature of these samples was verified by XRD. Glass transition, crystallization and thermal stability were determined by TG-DTA investigations. Direct optical energy band gaps before and after doping with different percents of copper oxide were evaluated from 4.81 eV to 2.99 eV indicated the role of copper in the glassy matrix by UV spectra. FTIR spectrum reveals characteristic absorption bands due to various groups of triangular and tetrahedral borate network. Due to the amorphous nature, the particles like agglomerates on the glass surface were investigated by the HRSEM analysis. The crystalline nature of the samples in XRD is confirmed by SAED pattern using HRTEM.

  18. Effects of copper on the preparation and characterization of Na-Ca-P borate glasses.

    PubMed

    Shailajha, S; Geetha, K; Vasantharani, P; Sheik Abdul Kadhar, S P

    2015-03-01

    Glasses in the system Na2O-CaO-B2O3-P2O5: CuO have been prepared by melt quenching at 1200°C and rapidly cooling at room temperature. The structural, optical and thermal properties have been investigated using X-ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform infrared (FTIR) spectroscopy, high resolution scanning electron microscopy (HRSEM) with energy dispersive X-ray (EDX) spectroscopy and high resolution transmission electron microscope (HRTEM) with energy dispersive X-ray (EDAX). The amorphous and crystalline nature of these samples was verified by XRD. Glass transition, crystallization and thermal stability were determined by TG-DTA investigations. Direct optical energy band gaps before and after doping with different percents of copper oxide were evaluated from 4.81eV to 2.99eV indicated the role of copper in the glassy matrix by UV spectra. FTIR spectrum reveals characteristic absorption bands due to various groups of triangular and tetrahedral borate network. Due to the amorphous nature, the particles like agglomerates on the glass surface were investigated by the HRSEM analysis. The crystalline nature of the samples in XRD is confirmed by SAED pattern using HRTEM. PMID:25605593

  19. EPR and optical absorption studies of Cu{sup 2+} ions in alkaline earth alumino borate glasses

    SciTech Connect

    Ramesh Kumar, V.; Rao, J.L. . E-mail: jlrao46@yahoo.co.in; Gopal, N.O.

    2005-08-11

    Electron paramagnetic resonance (EPR) and optical absorption spectra of Cu{sup 2+} ions in alkaline earth alumino borate glasses doped with different concentrations of CuO have been studied. The EPR spectra of all the glasses exhibit the resonance signals, characteristic of Cu{sup 2+} ions present in axially elongated octahedral sites. The number of spins participating in the resonance has been calculated as a function of temperature for calcium alumino borate (CaAB) glass doped with 0.1 mol% of CuO. From the EPR data, the paramagnetic susceptibility ({chi}) was calculated at different temperatures (T) and from the 1/{chi}-T graph, the Curie temperature of the glass has been evaluated. The optical absorption spectra of all the glasses show a single broad band, which has been assigned to the {sup 2}B{sub 1g} {yields} {sup 2}B{sub 2g} transition of the Cu{sup 2+} ions. The variation in the intensity of optical absorption with the ionic radius of the alkaline earth ion has been explained based on the Coulombic forces. By correlating the EPR and optical absorption spectral data, the nature of the in-plane {sigma} bonding between Cu{sup 2+} ion and the ligands is estimated. From the fundamental ultraviolet absorption edges of the glasses, the optical energy gap (E {sub opt}) and the Urbach energy ({delta}E) are evaluated. The variation in E {sub opt} and {delta}E is explained based on the number of defect centers in the glass.

  20. Effect of bioactive borate glass microstructure on bone regeneration, angiogenesis, and hydroxyapatite conversion in a rat calvarial defect model.

    PubMed

    Bi, Lianxiang; Rahaman, Mohamed N; Day, Delbert E; Brown, Zackary; Samujh, Christopher; Liu, Xin; Mohammadkhah, Ali; Dusevich, Vladimir; Eick, J David; Bonewald, Lynda F

    2013-08-01

    Borate bioactive glasses are biocompatible and enhance new bone formation, but the effect of their microstructure on bone regeneration has received little attention. In this study scaffolds of borate bioactive glass (1393B3) with three different microstructures (trabecular, fibrous, and oriented) were compared for their capacity to regenerate bone in a rat calvarial defect model. 12weeks post-implantation the amount of new bone, mineralization, and blood vessel area in the scaffolds were evaluated using histomorphometric analysis and scanning electron microscopy. The amount of new bone formed was 33%, 23%, and 15%, respectively, of the total defect area for the trabecular, oriented, and fibrous microstructures. In comparison, the percent new bone formed in implants composed of silicate 45S5 bioactive glass particles (250-300μm) was 19%. Doping the borate glass with copper (0.4 wt.% CuO) had little effect on bone regeneration in the trabecular and oriented scaffolds, but significantly enhanced bone regeneration in the fibrous scaffolds (from 15 to 33%). The scaffolds were completely converted to hydroxyapatite within the 12week implantation. The amount of hydroxyapatite formed, 22%, 35%, and 48%, respectively, for the trabecular, oriented, and fibrous scaffolds, increased with increasing volume fraction of glass in the as-fabricated scaffold. Blood vessels infiltrated into all the scaffolds, but the trabecular scaffolds had a higher average blood vessel area compared with the oriented and fibrous scaffolds. While all three scaffold microstructures were effective in supporting bone regeneration, the trabecular scaffolds supported more bone formation and may be more promising in bone repair. PMID:23643606

  1. The preparation and characterization of a lithium borate glass prepared by the gel technique

    NASA Technical Reports Server (NTRS)

    Weinberg, M. C.; Neilson, G. F.; Smith, G. L.; Dunn, B.; Moore, G. S.; Mackenzie, J. D.

    1985-01-01

    The preparation of an amorphous lithium borate gel by the metal organic procedure is described. In addition, a preliminary evaluation of the behavior of the gel upon heating is given. In particular the crystallization tendency of the gel is studied with the aid of DTA and X-ray diffraction, and the structural changes in the gel are monitored with the aid of IR spectroscopy. The glass produced from the lithium borate gel is compared to both the gel precursor material and a glass of similar composition prepared by conventional techniques. Specifically, the relevant water contents, crystallization behavior, and structural features are contrasted.

  2. Heat capacity, glass transition temperature, size of cooperatively rearranging regions, and network connectivity of sodium silicate and alkali borate glasses

    SciTech Connect

    Borisova, N.V.; Ushakov, V.M.; Shultz, M.M.

    1994-07-01

    The radius of cooperatively rearranging domains at the glass transition in sodium silicate glasses and the number of bridging oxygen atoms in these domains are assessed within the framework of the kinetic theory of thermal fluctuations. The tendencies of the heat capacity, T{sub g}, and the cooperative rearrangement scale with the alkali oxide concentration in sodium silicate and alkali borate glasses are compared. The points of similarity and distinctions between them are revealed.

  3. Ultrasonic and Thermal Properties of Borate and Phosphate Glasses Containing Bismuth and Lead

    SciTech Connect

    Aziz, Sidek Hj. Abd.; Ahmad, Hamezan; Wahab, Zaidan A.; Sulaiman, Zainal Abidin; Talib, Zainal Abidin; Shaari, A. Halim; Senin, H. B.

    2007-05-09

    Systematic series of (B2O3,P2O5)-Bi2O3-PbO glasses have been successfully prepared by using the rapid quenching technique in which each oxide content changes for every series on the basis of its weight percentage. Their amorphous natures were confirmed earlier by the x-ray diffraction technique. The experimental results show that the density of both glasses, determined by using the Archimedes principle, increases with the glass modifier content. This is due to the replacement of Bi2O3 and PbO in the borate and phosphate glassy networks. The molar volume for borate glass increases with the addition of bismuth and lead oxides, but a reverse trend occurs for the phosphate glass. The longitudinal and shear ultrasound velocities, determined by the MBS 8000 system, of both lead bismuth borate and phosphate glasses show a decreasing trend as more PbO and Bi2O3 are added to the glass system. The increase in PbO/Bi2O3 content was probably related to the progressive increase in the concentration of non-bridging oxygen (NBOs). Thermal studies of the glass, using the Labsys DTA-Setaram machine, show that the value of the glass transition temperature (Tg) is closely related to the chemical bond in the system. In lead bismuth borate glasses, the addition of more Pb2+ and Bi3+ results in a more dominant ionic bond character in the system and hence decreases Tg of the sample. However, in lead bismuth phosphate glasses, the addition of Pb2+ and Bi3+ not only failed to weaken the covalent character in P-O-P bonds, but strengthened it further, leading to an increment in the values of Tg.

  4. In vitro evaluation of cytotoxicity of silver-containing borate bioactive glass.

    PubMed

    Luo, Shi-Hua; Xiao, Wei; Wei, Xiao-Juan; Jia, Wei-Tao; Zhang, Chang-Qing; Huang, Wen-Hai; Jin, Dong-Xu; Rahaman, Mohamed N; Day, Delbert E

    2010-11-01

    The cytotoxicity of silver-containing borate bioactive glass was evaluated in vitro from the response of osteoblastic and fibroblastic cells in media containing the dissolution products of the glass. Glass frits containing 0-2 weight percent (wt %) Ag were prepared by a conventional melting and quenching process. The amount of Ag dissolved from the glass into a simulated body fluid (SBF), measured using atomic emission spectroscopy, increased rapidly within the first 48 h, but slowed considerably at longer times. Structural and microchemical analysis showed that the formation of a hydroxyapatite-like layer on the glass surface within 14 days of immersion in the SBF. The response of MC3T3-E1 and L929 cells to the dissolution products of the glass was evaluated using SEM observation of cell morphology, and assays of MTT hydrolysis, lactate dehydrogenase release, and alkaline phosphatase activity after incubation for up to 48 h. Cytotoxic effects were found for the borate glass containing 2 wt % Ag, but not for 0.75 and 1 wt % Ag. This borate glass containing up to ∼1 wt % Ag could provide a coating material for bacterial inhibition and enhanced bioactivity of orthopaedic implant materials such as titanium. PMID:20878930

  5. Radiation damage of alkali borate glasses for application in safe nuclear waste disposal

    NASA Astrophysics Data System (ADS)

    Baccaro, S.; Catallo, N.; Cemmi, A.; Sharma, G.

    2011-01-01

    The Electron Paramagnetic Resonance technique has been used to study the time decay of paramagnetic species induced by gamma irradiation and the radiation hardness of different alkali borate glasses for their application in safe nuclear waste disposal. Glasses with different composition have been prepared by conventional melt-quenching. Glass compositions have been chosen to elucidate the role of different alkali cations and of aluminium oxide on the borate glass network. The paramagnetic states detected in these glasses have been attributed, according to the literature, to the formation of hole centers associated with threefold coordinated boron. The results indicate that the time decay trend of the different glasses is slow and that the constant decay does not appear related to the chemical composition. Moreover, the undesired strong fading of the radiation-induced signal during the first 24 h after irradiation, observable in silicate glasses has not been detected. Although no species detectable by a X band spectrometer have been generated, the interaction of lithium borate glasses with air seem to accelerate the system decay rate. Annealing was finally performed and optimized, investigating the correlation between the chemical composition and the radiation damage recovery.

  6. Evaluation of borate bioactive glass scaffolds with different pore sizes in a rat subcutaneous implantation model.

    PubMed

    Deliormanli, Aylin M; Liu, Xin; Rahaman, Mohamed N

    2014-01-01

    Borate bioactive glass has been shown to convert faster and more completely to hydroxyapatite and enhance new bone formation in vivo when compared to silicate bioactive glass (such as 45S5 and 13-93 bioactive glass). In this work, the effects of the borate glass microstructure on its conversion to hydroxyapatite (HA) in vitro and its ability to support tissue ingrowth in a rat subcutaneous implantation model were investigated. Bioactive borate glass scaffolds, designated 13-93B3, with a grid-like microstructure and pore widths of 300, 600, and 900 µm were prepared by a robocasting technique. The scaffolds were implanted subcutaneously for 4 weeks in Sprague Dawley rats. Silicate 13-93 glass scaffolds with the same microstructure were used as the control. The conversion of the scaffolds to HA was studied as a function of immersion time in a simulated body fluid. Histology and scanning electron microscopy were used to evaluate conversion of the bioactive glass implants to hydroxyapatite, as well as tissue ingrowth and blood vessel formation in the implants. The pore size of the scaffolds was found to have little effect on tissue infiltration and angiogenesis after the 4-week implantation. PMID:23241965

  7. Effects of borate-based bioactive glass on neuron viability and neurite extension.

    PubMed

    Marquardt, Laura M; Day, Delbert; Sakiyama-Elbert, Shelly E; Harkins, Amy B

    2014-08-01

    Bioactive glasses have recently been shown to promote regeneration of soft tissues by positively influencing tissue remodeling during wound healing. We were interested to determine whether bioactive glasses have the potential for use in the treatment of peripheral nerve injury. In these experiments, degradable bioactive borate glass was fabricated into rods and microfibers. To study the compatibility with neurons, embryonic chick dorsal root ganglia (DRG) were cultured with different forms of bioactive borate glass. Cell viability was measured with no media exchange (static condition) or routine media exchange (transient condition). Neurite extension was measured within fibrin scaffolds with embedded glass microfibers or aligned rod sheets. Mixed cultures of neurons, glia, and fibroblasts growing in static conditions with glass rods and microfibers resulted in decreased cell viability. However, the percentage of neurons compared with all cell types increased by the end of the culture protocol compared with culture without glass. Furthermore, bioactive glass and fibrin composite scaffolds promoted neurite extension similar to that of control fibrin scaffolds, suggesting that glass does not have a significant detrimental effect on neuronal health. Aligned glass scaffolds guided neurite extension in an oriented manner. Together these findings suggest that bioactive glass can provide alignment to support directed axon growth. PMID:24027222

  8. Concentration Effect of Sm3+ Ions on Structural and Luminescence Properties of Lithium Borate Glasses

    NASA Astrophysics Data System (ADS)

    Ramteke, D. D.; Ganvir, V. Y.; Munishwar, S. R.; Gedam, R. S.

    Sm3+ containing lithium borate glasses successfully prepared and their physical and spectroscopic properties were analyzed. Addition of Sm3+ ions increases the density of glasses due to creation of BO-4 units. The absorption spectra of Sm3+ containing glasses show number of transition peaks as compared to base glass. Tau's method is employed to find the optical energy band gap of glasses. The value of optical energy band gap decreases with increase in Sm3+ content which is explained on the basis of structural changes. From the excitation spectra it is clear that these glasses can be easily excited by UV and near UV light. On excitation these glasses show strong emission at 598 nm which corresponds to 4G5/2→6H7/2 transition. Luminescence results indicate that these glasses can be further modified for LED applications.

  9. The effect of composition on the viscosity, crystallization and dissolution of simple borate glasses and compositional design of borate based bioactive glasses

    NASA Astrophysics Data System (ADS)

    Goetschius, Kathryn Lynn

    Borate glasses have recently been developed for a variety of medical applications, but much less is known about their structures and properties than more common silicate glasses. Melt properties and crystallization tendency for compositions in the Na2O-CaO-B2O3 system were characterized using differential thermal analysis and viscosity measurements. Characteristic viscosity (isokom) temperatures varied with the ratio between the modifier content (Na2O+CaO) and B2O3, particularly at lower temperatures, consistent with the changes in the relative concentrations of tetrahedral borons in the glass structure. Similar glasses were used to study dissolution processes in water. These alkali-alkaline earth glasses dissolve congruently and follow linear dissolution kinetics. The dissolution rates were dependent on the glass structure, with slower rates associated with greater fractions of four-coordinated boron. For glasses with a fixed alkaline earth identity, the dissolution rates increased in the order Liglasses with a constant alkali identity, the dissolution rates increased in the order Caborate-based bioactive compositions for specific applications. Melt viscosity, thermal expansion coefficient, liquidus temperature and crystallization tendency were determined, as were dissolution rates in simulated body fluid (SBF).

  10. Compositional dependence of Judd-Ofelt parameters in silicate, borate, and phosphate glasses

    SciTech Connect

    Takebe, Hiromichi; Nageno, Yoshikazu; Morinaga, Kenji

    1995-05-01

    Judd-Ofelt parameters {Omega}{sub t} with t = 2, 4, 6 for the rare-earth ions Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Ho{sup 3+}, Er{sup 3+}, and Tm{sup 3+} in alkali and/or alkaline-earth silicate, borate, and phosphate glasses have been determined. The variations of {Omega}{sub t} with the number of 4{line_integral} electrons of the rare-earth ions are demonstrated, and factors affecting the Judd-Ofelt parameters {Omega}{sub 6} are discussed. The intensity parameter {Omega}{sub 6} depends on the ionic packing ratio of the glass host by changing modifier type in silicate and borate glasses, and it is independent of that in a series of borate glasses as a function of modifier content and phosphate glasses. The peak wavenumber of the transitions whose intensities are determined mainly by the {Omega}{sub 6} < {parallel}U{sup (6)}{parallel}>{sup 2} term-where <{parallel}U{sup (6)}{parallel}> is one of the reduced matrix elements--shift systematically with the values of {Omega}{sub 6} for all the rare-earth ions.

  11. The effect of MgO on the optical properties of lithium sodium borate doped with Cu+ ions

    NASA Astrophysics Data System (ADS)

    Alajerami, Yasser Saleh Mustafa; Hashim, Suhairul; Hassan, Wan Muhamad Saridan Wan; Ramli, Ahmad Termizi; Saleh, Muneer Aziz

    2013-04-01

    The current work presented the photoluminescence (PL) properties of a new glass system, which are reported for the first time. Based on the attractive properties of borate glass, a mixture of boric acid (70-x mol %) modified with lithium (20 mol %) and sodium carbonate (10 mol %) was prepared. The current study illustrated the effect of dopant and co-dopant techniques on the lithium sodium borate (LNB). Firstly, 0.1 mol % of copper ions doped with LNB was excited at 610 nm. The emission spectrum showed two prominent peaks in the violet region (403 and 440 nm). Then, we remarked the effect of adding different concentration of MgO on the optical properties of LNB. The results showed the great effect of magnesium oxide on the PL intensities (enhanced more than two times). Moreover, an obvious shifting has been defined toward the blue region (440 → 475 nm). The up-conversion optical properties were observed in all emission spectra. This enhancement is contributed to the energy transfer from MgO ions to monovalent Cu+ ion. It is well known that magnesium oxide alone generates weak emission intensity, but during this increment the MgO act as an activator (co-doped) for Cu+ ions. Finally, energy band gap, density, ion concentration, molar volume, Polaron radius and inter-nuclear distance all were measured for the current samples. The current samples were subjected to XRD for amorphous confirmation and IR for glass characterization before and after dopants addition. Finally, some of significant physical and optical parameters were also calculated.

  12. Effect of SnO addition on optical absorption of bismuth borate glass and photocatalytic property of the crystallized glass

    SciTech Connect

    Masai, Hirokazu; Fujiwara, Takumi; Mori, Hiroshi

    2008-04-07

    We have found that an addition of SnO in a bismuth-borate glass, CaO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-TiO{sub 2}, decreases the optical absorption coefficient in the visible region, in which selective crystallization of TiO{sub 2} was observed after heat treatment. Since selective crystallization of TiO{sub 2} was also attained in the SnO-containing glass, the transparency of TiO{sub 2} crystallized glass can be improved independently of selective crystallization of TiO{sub 2}. We have also demonstrated that the rutile-nanocrystallized glass with SnO addition shows a higher photocatalytic activity than the glass without SnO, indicating that this crystallized glass has a large potential for application as transparent photocatalytic materials.

  13. Treatment of osteomyelitis and repair of bone defect by degradable bioactive borate glass releasing vancomycin.

    PubMed

    Xie, Zongping; Liu, Xin; Jia, Weitao; Zhang, Changqing; Huang, Wenhai; Wang, Jianqiang

    2009-10-15

    The effectiveness of a degradable and bioactive borate glass has been compared with the clinically used calcium sulfate in the treatment of osteomyelitis of rabbits, as a carrier for vancomycin. The bone infections were induced in the tibias of 65 rabbits by injecting methicillin-resistant Staphylococcus aureus (MRSA). After 3 weeks, these rabbits were distributed into 4 groups and treated by debridement. Pure borate glass (BG), vancomycin-loaded calcium sulfate (VCS) and vancomycin-loaded borate glass (VBG) were implanted into the infection sites of groups 2 to 4 respectively. After 8 weeks, the effectiveness of treatment was assessed radiographically, bacteriologically, and histopathologically. The results showed that the negative rates of MRSA examination for rabbits were 36.36%, 18.18%, 73.33% and 81.25% respectively for groups 1 to 4. Significant differences were observed radiographically, bacteriologically, and histopathologically between groups 1 and 4, groups 2 and 3, and between groups 2 and 4. The best result of treatment was observed in group 4. Radiographically, VBG was found to be mostly reabsorbed and replaced by lots of new bones, whereas, VCS was completely reabsorbed and replaced by modest new bones. Histopathologically, there were lots of newly formed bones around VBG without any foreign body response, and only modest new bones around VCS with obvious foreign body response. VBG proved to have excellent biocompatibility and to be very effective in eradicating osteomyelitis and simultaneously stimulating bone regeneration, avoiding the disadvantages of VCS. PMID:19545593

  14. Complex Heat Capacity of Lithium Borate Glasses Studied by Modulated DSC

    NASA Astrophysics Data System (ADS)

    Matsuda, Yu; Matsui, Chihiro; Ike, Yuji; Kodama, Masao; Kojima, Seiji

    2006-05-01

    Complex heat capacity, Cp* = Cp' - iCp?, of lithium borate glasses Li2O?(1-x)B2O3 (x = 0.00 - 0.33) has been investigated by Modulated DSC (MDSC). We have successfully observed the frequency dependent Cp* by MDSC in the frequency range 0.01 to 0.1 Hz, and the average relaxation time of glass transition has been determined as a function of temperature. Moreover, the composition dependence of the thermal properties has been investigated. The calorimetric glass transition temperatures become higher with the increase of concentration of Li2O and show the board maximum around x = 0.26-0.28. The width of glass transition region becomes narrower as Li2O increases. These results relate to the change of the fragility of the system. It has been proven that the complex heat capacity spectroscopy by MDSC is a powerful tool to investigate the glass transition phenomena.

  15. Structure and dissolution investigation of calcium-bismuth-borate glasses and vitroceramics containing silver.

    PubMed

    Simon, V; Spinu, M; Stefan, R

    2007-03-01

    Quaternary Ag(2)O-CaO-Bi(2)O(3)-B(2)O(3) glasses and glassceramics are investigated with regard to release behaviour and local structure. The dissolution behaviour in water and physiological serum shows that the cations are released rapidly or gradually and points out a multi-step process, generally characterised by higher rates in water than in physiological serum. The structural effect of silver addition to bismuth-borate glasses is observed from infrared spectroscopic data. The antibacterial activity of the investigated samples was tested on six bacterial media. PMID:17334702

  16. Study of Electrical Conductivity and Dielectric Behaviour of Molybdenum containing Bismuth Borate Glasses

    NASA Astrophysics Data System (ADS)

    Kishore, N.; Sanjay; Agarwal, A.; Dahiya, Sanjay; Pal, Inder

    2015-02-01

    Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenching technique. The samples have been characterized by X-ray diffraction and scanning electron microscopy. Frequency and temperature dependent conductivity measurements have been carried out in the range of 20Hz to 1MHz and in the temperature range of 373K to 623K respectively. The frequency dependent conductivity has been studied using both conductivity and modulus formalisms. The dielectric permittivity (ε' and ε"), electrical modulus (M*) and dielectric loss were also studied of the prepared glasses. The values of ε' and ε'' are found to decrease with increase in frequency.

  17. Role of electron transfer in Ce3+ sensitized Yb3+ luminescence in borate glass

    NASA Astrophysics Data System (ADS)

    Sontakke, Atul D.; Ueda, Jumpei; Katayama, Yumiko; Zhuang, Yixi; Dorenbos, Pieter; Tanabe, Setsuhisa

    2015-01-01

    In a Ce3+-Yb3+ system, two mechanisms are proposed so far namely, the quantum cutting mechanism and the electron transfer mechanism explaining Yb3+ infrared luminescence under Ce3+ excitation. Among them, the quantum cutting mechanism, where one Ce3+ photon (ultraviolet/blue) gives rise to two Yb3+ photons (near infrared) is widely sought for because of its huge potential in enhancing the solar cell efficiency. In present study on Ce3+-Yb3+ codoped borate glasses, Ce3+ sensitized Yb3+ luminescence at ˜1 μm have been observed on Ce3+ 5d state excitation. However, the intensity of sensitized Yb3+ luminescence is found to be very weak compared to the strong quenching occurred in Ce3+ luminescence in Yb3+ codoped glasses. Moreover, the absolute luminescence quantum yield also showed a decreasing trend with Yb3+ codoping in the glasses. The overall behavior of the luminescence properties and the quantum yield is strongly contradicting with the quantum cutting phenomenon. The results are attributed to the energetically favorable electron transfer interactions followed by Ce3+-Yb3+ ⇌ Ce4+-Yb2+ inter-valence charge transfer and successfully explained using the absolute electron binding energies of dopant ions in the studied borate glass. Finally, an attempt has been presented to generalize the electron transfer mechanism among opposite oxidation/reduction property dopant ions using the vacuum referred electron binding energy (VRBE) scheme for lanthanide series.

  18. Effect of Sm{sub 2}O{sub 3} addition on electrical and optical properties of lithium borate glasses

    SciTech Connect

    Gedam, R. S.; Ramteke, D. D.

    2012-06-05

    The electrical and optical property of lithium borate glasses was investigated. It is observed that conductivity decreases while density and refractive index increases with the addition of Sm{sub 2}O{sub 3}. Radiation length of glasses was determined and it is observed that radiation length decreases with the addition of Sm{sub 2}O{sub 3}.

  19. Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives.

    PubMed

    Abdelghany, A M; Ouis, M A; Azooz, M A; ElBatal, H A; El-Bassyouni, G T

    2016-01-01

    Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680cm(-1) after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content. PMID:26204506

  20. Role of SrO on the bioactivity behavior of some ternary borate glasses and their glass ceramic derivatives

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; Ouis, M. A.; Azooz, M. A.; ElBatal, H. A.; El-Bassyouni, G. T.

    2016-01-01

    Borate glasses containing SrO substituting both CaO and NaO were prepared and characterized for their bioactivity or bone bonding ability. Glass ceramic derivatives were prepared by thermal heat treatment process. FTIR, XRD and SEM measurements for the prepared glass and glass-ceramics before and after immersion in sodium phosphate solution for one and two weeks were carried out. The appearance of two IR peaks within the range 550-680 cm-1 after immersion in phosphate solution indicates the formation of hydroxyapatite or equivalent Sr phosphate layer. X-ray diffraction data agree with the FTIR spectral analysis. The solubility test was carried out for both glasses and glass ceramics derivatives in the same phosphate solution. The introduction of SrO increases the solubility for both glasses and glass ceramics and this is assumed to be due to the formation of Sr phosphate which is more soluble than calcium phosphate (hydroxyapatite). SEM images reveal varying changes in the surfaces of glass ceramics after immersion according to the SrO content.

  1. Studies on the effect of Li{sub 2}SO{sub 4} on the structure of lithium borate glasses

    SciTech Connect

    Ganguli, M.; Rao, K.J.

    1999-02-11

    Thermal and spectroscopic investigations have been carried out on a number of glasses with a wide range of compositions in the pseudoternary glass system, Li{sub 2}SO{sub 4}-Li{sub 2}O-B{sub 2}O{sub 3}, to understand the role of sulfate ions in modifying the borate glass structure. Both nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic results indicate that four-coordinate boron atoms are retained in the glass structure to a greater extent in sulfate-containing glasses than in pure lithium borate glasses. There seems to be some evidence for the existence of sulfoborate-type units in Raman spectra in the region of 800--960 cm{sup {minus}1}. These conclusions are supported by the observed behavior of glass transition temperatures and molar volumes. The possibility of formation of sulfoborate-type units is discussed from bonding and thermodynamic points of view.

  2. Synthesis and characterization of cerium- and gallium-containing borate bioactive glass scaffolds for bone tissue engineering.

    PubMed

    Deliormanlı, Aylin M

    2015-02-01

    Bioactive glasses are widely used in biomedical applications due to their ability to bond to bone and even to soft tissues. In this study, borate based (13-93B3) bioactive glass powders containing up to 5 wt% Ce2O3 and Ga2O3 were prepared by the melt quench technique. Cerium (Ce+3) and gallium (Ga+3) were chosen because of their low toxicity associated with bacteriostatic properties. Bioactive glass scaffolds were fabricated using the polymer foam replication method. In vitro degradation and bioactivity of the scaffolds were evaluated in SBF under static conditions. Results revealed that the cerium- and gallium-containing borate glasses have much lower degradation rates compared to the bare borate glass 13-93B3. In spite of the increased chemical durability, substituted glasses exhibited a good in vitro bioactive response except when the Ce2O3 content was 5 wt%. Taking into account the high in vitro hydroxyapatite forming ability, borate glass scaffolds containing Ce+3 and Ga+3 therapeutic ions are promising candidates for bone tissue engineering applications. PMID:25631259

  3. Spectroscopic properties of Pr3+ ions embedded in lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Ramteke, D. D.; Swart, H. C.; Gedam, R. S.

    2016-01-01

    A series of lithium borate glasses with different Pr3+ contents were prepared by the melt quench technique to explore the new material for solid state light applications. We found that the addition of Pr3+ ions in the glass matrix has a profound effect on the properties of the glasses. The presence of Pr3+ ions in the glass matrix created various absorption bands compared to the base glass. These bands were due to the ground state (3H4) of the Pr3+ to the various excited states. Optical energy band gap was calculated by Tauc's method which showed a decreasing trend with an increase in the Pr3+ content. This might be due to structural changes when the glass structure became rigid due to the Pr3+ ions and this was confirmed by the density results. Rigidity of the glass structure was further confirmed by the Fourier transformed infrared results. The excitation spectra showed bands at 3H4→3P2, 3P1 and 3P0 nm. The 3H4→3P2 band was used to study the unresolved 1D2→3H4 and 3P0→3H6 transitions of the Pr3+ ions.

  4. Molecular Dynamics Simulation of Lead Borate and Related Glasses in Multicomponent Systems for Low Melting Vitrification of Nuclear Wastes

    NASA Astrophysics Data System (ADS)

    Kato, S.; Sakida, S.; Benino, Y.; Nanba, T.

    2011-03-01

    Glasses based on lead oxide have excellent properties in general such as low melting point, high chemical durability and high stability of glassy form, which are suitable for the preservation of volatile nuclear wastes in a permanent vitrified form. In order to confirm the long-term performance of lead borate based glasses it is necessary to establish dissolution and diffusion processes based on a reliable model of the glass structure. In the present study molecular dynamics (MD) simulation of lead borate based glasses was carried out introducing a dummy negative point charge to reproduce asymmetric PbOn units. Parameters for the dummy charge were optimized based on the comparison between calculated radial distribution function and experimental one. Asymmetric coordination around Pb, for example trigonal bipyramid, was successfully reproduced in the MD simulated binary and ternary glass models. The simple model using the dummy charge was confirmed to be valid for further simulations of multicomponent glasses containing nuclear wastes and heavy elements.

  5. Self-frequency-doubling of ultrafast laser inscribed neodymium doped yttrium aluminum borate waveguides

    NASA Astrophysics Data System (ADS)

    Dong, Ningning; Martínez de Mendivil, J.; Cantelar, E.; Lifante, G.; Vázquez de Aldana, J.; Torchia, G. A.; Chen, Feng; Jaque, Daniel

    2011-05-01

    Buried channel optical waveguides, supporting orthogonal polarizations, have been fabricated in a neodymium doped yttrium aluminum borate nonlinear laser crystal by ultrafast laser inscription following the so-called "double line" approach. Confocal fluorescence and second harmonic imaging experiments have revealed that the original fluorescence and nonlinear properties have been not deteriorated by the waveguide inscription procedure. Preliminary laser experiments have shown the ability of the fabricated structures for green laser light generation under 808 nm optical pumping by self-frequency-doubling of the 1.06 μm laser line of neodymium ions.

  6. Evaluation of injectable strontium-containing borate bioactive glass cement with enhanced osteogenic capacity in a critical-sized rabbit femoral condyle defect model.

    PubMed

    Zhang, Yadong; Cui, Xu; Zhao, Shichang; Wang, Hui; Rahaman, Mohamed N; Liu, Zhongtang; Huang, Wenhai; Zhang, Changqing

    2015-02-01

    The development of a new generation of injectable bone cements that are bioactive and have enhanced osteogenic capacity for rapid osseointegration is receiving considerable interest. In this study, a novel injectable cement (designated Sr-BBG) composed of strontium-doped borate bioactive glass particles and a chitosan-based bonding phase was prepared and evaluated in vitro and in vivo. The bioactive glass provided the benefits of bioactivity, conversion to hydroxyapatite, and the ability to stimulate osteogenesis, while the chitosan provided a cohesive biocompatible and biodegradable bonding phase. The Sr-BBG cement showed the ability to set in situ (initial setting time = 11.6 ± 1.2 min) and a compressive strength of 19 ± 1 MPa. The Sr-BBG cement enhanced the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro when compared to a similar cement (BBG) composed of chitosan-bonded borate bioactive glass particles without Sr. Microcomputed tomography and histology of critical-sized rabbit femoral condyle defects implanted with the cements showed the osteogenic capacity of the Sr-BBG cement. New bone was observed at different distances from the Sr-BBG implants within eight weeks. The bone-implant contact index was significantly higher for the Sr-BBG implant than it was for the BBG implant. Together, the results indicate that this Sr-BBG cement is a promising implant for healing irregularly shaped bone defects using minimally invasive surgery. PMID:25591177

  7. Spectroscopic properties of Pr3+ and Er3+ ions in lead-free borate glasses modified by BaF2

    NASA Astrophysics Data System (ADS)

    Pisarska, Joanna; Pisarski, Wojciech A.; Dorosz, Dominik; Dorosz, Jan

    2015-09-01

    Lead-free oxyfluoride borate glasses singly doped with Pr3+ and Er3+ were prepared and next investigated using absorption and luminescence spectroscopy. In the studied glass system, barium oxide was substituted by BaF2. Two luminescence bands of Pr3+ located at visible spectral region are observed, which correspond to 3P0-3H4 (blue) and 1D2-3H4 (reddish orange) transitions, respectively. The luminescence bands due to 1D2-3H4 transition of Pr3+ are shifted to shorter wavelengths, when BaO was substituted by BaF2. Near-infrared luminescence spectra of Er3+ ions in lead-free borate glasses modified by BaF2 correspond to 4I13/2-4I15/2 transition. Their spectral linewidths increase with increasing BaF2 concentration. The changes in measured lifetimes of rare earth ions are well correlated with the bonding parameters calculated from the optical absorption spectra.

  8. Gentamicin-Loaded Borate Bioactive Glass Eradicates Osteomyelitis Due to Escherichia coli in a Rabbit Model

    PubMed Central

    Xie, Zongping; Cui, Xu; Zhao, Cunju; Huang, Wenhai; Wang, Jianqiang

    2013-01-01

    The treatment of osteomyelitis induced by Gram-negative bacilli is rarely reported in the literature. This study established a rabbit tibia model of osteomyelitis induced by the Gram-negative bacillus Escherichia coli. Using this model, pellets composed of a chitosan-bonded mixture of borate bioactive glass and gentamicin were evaluated in vitro and in vivo for the treatment of osteomyelitis induced by Escherichia coli. Our results showed that the pellets in phosphate-buffered saline released gentamicin continuously over 26 days. Without the simultaneous use of a systemic antibiotic, the implantation of the gentamicin-loaded pellets into the osteomyelitis region of the tibia resulted in the eradication of 81.82% of infections, as determined by microbiological, histological and radiographic evaluation, and supported the ingrowth of new bone into the tibia defects after 6 weeks of implantation. The results indicate that the gentamicin-loaded borate bioactive glass implant, combining sustained drug release with the ability to support new bone formation, could provide a method for treating osteomyelitis induced by Gram-negative bacilli. PMID:23629702

  9. Gentamicin-loaded borate bioactive glass eradicates osteomyelitis due to Escherichia coli in a rabbit model.

    PubMed

    Xie, Zongping; Cui, Xu; Zhao, Cunju; Huang, Wenhai; Wang, Jianqiang; Zhang, Changqing

    2013-07-01

    The treatment of osteomyelitis induced by Gram-negative bacilli is rarely reported in the literature. This study established a rabbit tibia model of osteomyelitis induced by the Gram-negative bacillus Escherichia coli. Using this model, pellets composed of a chitosan-bonded mixture of borate bioactive glass and gentamicin were evaluated in vitro and in vivo for the treatment of osteomyelitis induced by Escherichia coli. Our results showed that the pellets in phosphate-buffered saline released gentamicin continuously over 26 days. Without the simultaneous use of a systemic antibiotic, the implantation of the gentamicin-loaded pellets into the osteomyelitis region of the tibia resulted in the eradication of 81.82% of infections, as determined by microbiological, histological and radiographic evaluation, and supported the ingrowth of new bone into the tibia defects after 6 weeks of implantation. The results indicate that the gentamicin-loaded borate bioactive glass implant, combining sustained drug release with the ability to support new bone formation, could provide a method for treating osteomyelitis induced by Gram-negative bacilli. PMID:23629702

  10. In vivo and in vitro studies of borate based glass micro-fibers for dermal repairing.

    PubMed

    Zhou, Jie; Wang, Hui; Zhao, Shichang; Zhou, Nai; Li, Le; Huang, Wenhai; Wang, Deping; Zhang, Changqing

    2016-03-01

    Full-thickness skin defects represent urgent clinical problem nowadays. Wound dressing materials are hotly needed to induce dermal reconstruction or to treat serious skin defects. In this study, the borate bioactive glass (BG) micro-fibers were fabricated and compared with the traditional material 45S5 Bioglass(®) (SiG) micro-fibers. The morphology, biodegradation and bioactivity of BG and SiG micro-fibers were investigated in vitro. The wound size reduction and angiogenic effects of BG and SiG micro-fibers were evaluated by the rat full-thickness skin defect model and Microfil technique in vivo. Results indicated that the BG micro-fibers showed thinner fiber diameter (1μm) and better bioactivity than the SiG micro-fibers did. The ionic extracts of BG and SiG micro-fibers were not toxic to human umbilical vein endothelial cells (HUVECs). In vivo, the BG micro-fiber wound dressings obviously enhanced the formation of blood vessel, and resulted in a much faster wound size reduction than the SiG micro-fibers, or than the control groups, after 9days application. The good skin defect reconstruction ability of BG micro-fibers contributed to the B element in the composition, which results in the better bioactivity and angiogenesis. As shown above, the novel bioactive borate glass micro-fibers are expected to provide a promising therapeutic alternative for dermal reconstruction or skin defect repair. PMID:26706550

  11. Effect of TeO 2 on the elastic moduli of sodium borate glasses

    NASA Astrophysics Data System (ADS)

    Saddeek, Yasser B.; Latif, Lamia. Abd El

    2004-05-01

    Sodium borate glass containing tellurite as Te xNa 2-2 xB 4-4 xO 7-5 x with x=0, 0.05, 0.15, 0.25 and 0.35 have been prepared by rapid quenching. Ultrasonic velocity (both longitudinal and shear) measurements have been made using a transducer operated at the fundamental frequency of 4 MHz at room temperature. The density was measured by the conventional Archimedes method. The elastic moduli, the Debye temperature, Poisson's ratio, and the parameters derived from the Makishima-Mackenzie model and the bond compression model have been obtained as a function of TeO 2 content. The monotonic decrease in the velocities and the elastic moduli, and the increase in the ring diameter and the ratio Kbc/ Ke as a function of TeO 2 modifier content reveals the loose packing structure, which is attributed to the increase in the molar volume and the reduction in the vibrations of the borate lattice. The observed results confirm that the addition of TeO 2 changes the rigid character of Na 2B 4O 7 to a matrix of ionic behaviour bonds (NBOs). This is due to the creation of more and more discontinuities and defects in the glasses, thus breaking down the borax structure.

  12. UV-VIS-NIR spectral optical properties of silver iodide borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Di Marco, G.; Torrisi, L.; Branca, C.; Carini, G.; Wanderlingh, U.; D'Angelo, G.

    2014-04-01

    We present a study of optical properties of a series of silver iodide borate glasses(AgI)x(Ag2OB2O3)1-xby UV-VIS-NIR spectroscopy. The results show an increased absorbance in the whole analysed spectral range when the AgI concentration is augmented. In particular, the enhanced intensity of the wavelength band at 400-500 nm with silver iodine content suggests that this band arises from plasmon-related absorption, describing the formation of silver nanoparticles. With respect to this study, our results could motivate novel target designs consisting of ternary silver boron based bulk glasses for generating resonant absorption of laser light by plasma.

  13. In vitro bioactivity, cytocompatibility, and antibiotic release profile of gentamicin sulfate-loaded borate bioactive glass/chitosan composites.

    PubMed

    Cui, Xu; Gu, Yifei; Li, Le; Wang, Hui; Xie, Zhongping; Luo, Shihua; Zhou, Nai; Huang, Wenhai; Rahaman, Mohamed N

    2013-10-01

    Borate bioactive glass-based composites have been attracting interest recently as an osteoconductive carrier material for local antibiotic delivery. In the present study, composites composed of borate bioactive glass particles bonded with a chitosan matrix were prepared and evaluated in vitro as a carrier for gentamicin sulfate. The bioactivity, degradation, drug release profile, and compressive strength of the composite carrier system were studied as a function of immersion time in phosphate-buffered saline at 37 °C. The cytocompatibility of the gentamicin sulfate-loaded composite carrier was evaluated using assays of cell proliferation and alkaline phosphatase activity of osteogenic MC3T3-E1 cells. Sustained release of gentamicin sulfate occurred over ~28 days in PBS, while the bioactive glass converted continuously to hydroxyapatite. The compressive strength of the composite loaded with gentamicin sulfate decreased from the as-fabricated value of 24 ± 3 MPa to ~8 MPa after immersion for 14 days in PBS. Extracts of the soluble ionic products of the borate glass/chitosan composites enhanced the proliferation and alkaline phosphatase activity of MC3T3-E1 cells. These results indicate that the gentamicin sulfate-loaded composite composed of chitosan-bonded borate bioactive glass particles could be useful clinically as an osteoconductive carrier material for treating bone infection. PMID:23820937

  14. Complex Heat Capacity of Lithium Borate Glasses Studied by Modulated DSC

    SciTech Connect

    Matsuda, Yu; Ike, Yuji; Matsui, Chihiro; Kodama, Masao; Kojima, Seiji

    2006-05-05

    Complex heat capacity, C{sub p}* = C{sub p}' - iC{sub p}'', of lithium borate glasses Li2O{center_dot}(1-x)B2O3 (x = 0.00 - 0.33) has been investigated by Modulated DSC (MDSC). We have successfully observed the frequency dependent C{sub p}* by MDSC in the frequency range 0.01 to 0.1 Hz, and the average relaxation time of glass transition has been determined as a function of temperature. Moreover, the composition dependence of the thermal properties has been investigated. The calorimetric glass transition temperatures become higher with the increase of concentration of Li2O and show the board maximum around x = 0.26-0.28. The width of glass transition region becomes narrower as Li2O increases. These results relate to the change of the fragility of the system. It has been proven that the complex heat capacity spectroscopy by MDSC is a powerful tool to investigate the glass transition phenomena.

  15. Specific features of the optical properties of potassium-aluminum borate glasses with copper chloride nanocrystals at high temperatures

    NASA Astrophysics Data System (ADS)

    Shirshnev, P. S.; Babkina, A. N.; Tsekhomskii, V. A.; Nikonorov, N. V.

    2015-09-01

    It is shown that heating of potassium-aluminum borate glasses with CuCl nanocrystals above 80°C leads to the disappearance of exciton absorption peaks, whereas cooling below 50°C gives rise to these peaks. These effects are related, respectively, to the melting of nanocrystals and crystallization of nanophase.

  16. A novel injectable borate bioactive glass cement for local delivery of vancomycin to cure osteomyelitis and regenerate bone.

    PubMed

    Cui, Xu; Zhao, Cunju; Gu, Yifei; Li, Le; Wang, Hui; Huang, Wenhai; Zhou, Nai; Wang, Deping; Zhu, Yi; Xu, Jun; Luo, Shihua; Zhang, Changqing; Rahaman, Mohamed N

    2014-03-01

    Osteomyelitis (bone infection) is often difficult to cure. The commonly-used treatment of surgical debridement to remove the infected bone combined with prolonged systemic and local antibiotic treatment has limitations. In the present study, an injectable borate bioactive glass cement was developed as a carrier for the antibiotic vancomycin, characterized in vitro, and evaluated for its capacity to cure osteomyelitis in a rabbit tibial model. The cement (initial setting time = 5.8 ± 0.6 min; compressive strength = 25.6 ± 0.3 MPa) released vancomycin over ~25 days in phosphate-buffered saline, during which time the borate glass converted to hydroxyapatite (HA). When implanted in rabbit tibial defects infected with methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis, the vancomycin-loaded cement converted to HA and supported new bone formation in the defects within 8 weeks. Osteomyelitis was cured in 87 % of the defects implanted with the vancomycin-loaded borate glass cement, compared to 71 % for the defects implanted with vancomycin-loaded calcium sulfate cement. The injectable borate bioactive glass cement developed in this study is a promising treatment for curing osteomyelitis and for regenerating bone in the defects following cure of the infection. PMID:24477872

  17. A Novel Injectable Borate Bioactive Glass Cement as an Antibiotic Delivery Vehicle for Treating Osteomyelitis

    PubMed Central

    Cui, Xu; Gu, Yi-Fei; Jia, Wei-Tao; Rahaman, Mohamed N.; Wang, Yang; Huang, Wen-Hai; Zhang, Chang-Qing

    2014-01-01

    Background A novel injectable cement composed of chitosan-bonded borate bioactive glass (BG) particles was evaluated as a carrier for local delivery of vancomycin in the treatment of osteomyelitis in a rabbit tibial model. Materials and Methods The setting time, injectability, and compressive strength of the borate BG cement, and the release profile of vancomycin from the cement were measured in vitro. The capacity of the vancomycin-loaded BG cement to eradicate methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in rabbit tibiae in vivo was evaluated and compared with that for a vancomycin-loaded calcium sulfate (CS) cement and for intravenous injection of vancomycin. Results The BG cement had an injectability of >90% during the first 3 minutes after mixing, hardened within 30 minutes and, after hardening, had a compressive strength of 18±2 MPa. Vancomycin was released from the BG cement into phosphate-buffered saline for up to 36 days, and the cumulative amount of vancomycin released was 86% of the amount initially loaded into the cement. In comparison, vancomycin was released from the CS cement for up 28 days and the cumulative amount released was 89%. Two months post-surgery, radiography and microbiological tests showed that the BG and CS cements had a better ability to eradicate osteomyelitis when compared to intravenous injection of vancomycin, but there was no significant difference between the BG and CS cements in eradicating the infection. Histological examination showed that the BG cement was biocompatible and had a good capacity for regenerating bone in the tibial defects. Conclusions These results indicate that borate BG cement is a promising material both as an injectable carrier for vancomycin in the eradication of osteomyelitis and as an osteoconductive matrix to regenerate bone after the infection is cured. PMID:24427311

  18. Optical Absorption Spectra of Sodium Borate Cobalt Doped Glasses

    SciTech Connect

    Elokr, M. M.; Hassan, M. A.; Yaseen, A. M.; Elokr, R.

    2007-02-14

    Glassy system: xNa2O-(100-x-y)B2O3-yCo3O4 has been prepared by conventional melt quenching technique. Optical absorption spectra have been obtained in the range 300 - 2500 nm at room temperature. An absorption edge was observed in the near UV range, the analysis of which reveals that indirect transition is the dominant absorption mechanism. All prepared samples exhibit blue color, indicating that the Co ions are acted upon by tetrahedral ligand field. Obtained spectra were used to estimate some ligand field parameters.

  19. Effect of R(3+) ions on the structure and properties of lanthanum borate glasses

    NASA Technical Reports Server (NTRS)

    Chakraborty, I. N.; Day, D. E.

    1985-01-01

    The present investigation of glass formation in the (mole percent) systems 25La2O3 (x)R2O3 (75-x)B2O3, where R = Al, Ga, and (25-x)La2O3 (x)Ln2O3 75B2O3, where Ln = Gd, Er, Y, notes that up to 25 mol pct Al2O3 or Ga2O3 can be substituted for B2O3, while no more than about 5 mol pct Ln2O3, substituted for La2O3, caused macro-phase separation. The substitution of either R2O3 or Ln2O3 in the lanthanum borate system changes the separation distance between adjacent B3O6 chains. The effect of this structural change on the molar volume, transformation temperature, thermal expansion coefficient, and transformation-range viscosity is discussed.

  20. Femtosecond laser induced coordination transformation and migration of ions in sodium borate glasses

    SciTech Connect

    Liu Yin; Zhu Bin; Wang Li; Qiu Jianrong; Dai Ye; Ma Hongliang

    2008-03-24

    We report on the coordination transformation of B{sup 3+} ions and migration of Na{sup +} and O{sup 2-} ions in sodium borate glasses, induced by 250 kHz, 800 nm femtosecond laser irradiation. Micro-Raman spectra show that the ratio of the integrated intensity of the two peaks at 806 and 774 cm{sup -1} decreases at first and then increases with increasing distance from the center of the laser modified zone. Electron dispersive x-ray spectra show that a portion of Na{sup +} and O{sup 2-} ions migrate from the vicinity of focal point after the femtosecond laser irradiation. A possible mechanism is proposed to explain the observed phenomena.

  1. B K-Edge XANES of Superstructural Units in Borate Glasses

    SciTech Connect

    Sipr, O.; Simunek, A.; Rocca, F.

    2007-02-02

    The potential of x-ray absorption near-edge structure (XANES) spectroscopy for studying medium range order in borate glasses is assessed by theoretical modelling of the spectra. B K edge XANES is calculated in case that B atoms are located in isolated BO3 and BO4 units and in case that B atom are located in superstructural units of 9-15 atoms. It is found that boroxol ring and diborate and ditriborate superstructural units give rise to spectra which differ from spectra obtained by a mere superposition of spectra of isolated BO3 and BO4 units. On the other hand, spectra of pentaborate and triborate units do not differ significantly from spectra of isolated BO3 and BO4.

  2. Combination of platelet-rich plasma with degradable bioactive borate glass for segmental bone defect repair.

    PubMed

    Zhang, Ya-Dong; Wang, Gang; Sun, Yan; Zhang, Chang-Qing

    2011-02-01

    Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor significantly improves bone repair. In this study, a strategy combining degradable bioactive borate glass (BG) scaffolds with platelet-rich plasma (PRP) was tested. The bone defect was filled with BG alone, BG combined with autologous PRP or left empty. Bone formation was analyzed at 4, 8 and 12 weeks using both histology and radiology. The PRP treated group yielded better bone formation than the pure BG scaffold as determined by both histology and microcomputer tomography after 12 weeks. In conclusion, PRP improved bone healing in a diaphyseal rabbit model on BG. The combination of PRP and BG may be an effective approach to repair critical defects. PMID:21473456

  3. Optical properties of cerium doped oxyfluoroborate glass.

    PubMed

    Bahadur, A; Dwivedi, Y; Rai, S B

    2013-06-01

    Cerium doped oxyfluoroborate glasses have been prepared and its spectroscopic properties have been discussed. It is found that the absorption edge shifts towards the lower energy side for the higher concentration of cerium dopant. Optical band gap for these glasses have been calculated and it is found that the number of non-bridging oxygen increases with cerium content. The emission spectra of these glasses have been recorded using UV laser radiations (266 and 355 nm) and it is observed that these glasses show bright blue emission. On the basis of excitation and emission spectra we have reported the existence of at least two different emission centers of Ce(3+)ions. PMID:23583876

  4. New high capacity cathode materials for rechargeable Li-ion batteries: vanadate-borate glasses.

    PubMed

    Afyon, Semih; Krumeich, Frank; Mensing, Christian; Borgschulte, Andreas; Nesper, Reinhard

    2014-01-01

    V2O5 based materials are attractive cathode alternatives due to the many oxidation state switches of vanadium bringing about a high theoretical specific capacity. However, significant capacity losses are eminent for crystalline V2O5 phases related to the irreversible phase transformations and/or vanadium dissolution starting from the first discharge cycle. These problems can be circumvented if amorphous or glassy vanadium oxide phases are employed. Here, we demonstrate vanadate-borate glasses as high capacity cathode materials for rechargeable Li-ion batteries for the first time. The composite electrodes of V2O5 - LiBO(2) glass with reduced graphite oxide (RGO) deliver specific energies around 1000 Wh/kg and retain high specific capacities in the range of ~ 300 mAh/g for the first 100 cycles. V2O5 - LiBO(2) glasses are considered as promising cathode materials for rechargeable Li-ion batteries fabricated through rather simple and cost-efficient methods. PMID:25408200

  5. Polytypic modifications in heavily Tb and Eu doped gadolinium aluminum borate crystals

    NASA Astrophysics Data System (ADS)

    Beregi, E.; Saj, I.; Lengyel, K.; Bombicz, P.; Czugler, M.; Fldvri, I.

    2012-07-01

    The evidence of a new polytypic phase was demonstrated in double doped gadolinium aluminum borate (GAB) crystals grown by the high temperature top seeded solution growth (HTTSSG) method. The structures of the rhombohedral and the new monoclinic phases in the Eu0.02Tb0.12Gd0.86Al3(BO3)4 and Eu0.18Tb0.19Gd0.63Al3(BO3)4 compositions were determined by single crystal and powder X-ray diffraction methods. The monoclinic crystals with different compositions have identical structures with space group C2/c. It was concluded that the starting crystallization temperature was the dominant factor in formation of the rhombohedral and monoclinic phases. The crystals with non-centrosymmetric rhombohedral structure (R32) may possess similar compositions as the previous ones but their starting crystallization temperature was lower.

  6. Structural and scintillation properties of new Ce 3+-doped alumino-borate

    NASA Astrophysics Data System (ADS)

    Aloui-Lebbou, O.; Goutaudier, C.; Kubota, S.; Dujardin, C.; Cohen-Adad, M. Th.; Pdrini, C.; Florian, P.; Massiot, D.

    2001-02-01

    The compound LuAl 3(BO 3) 4 doped with Ce 3+ ions has been synthesized and investigated for the first time. It was compared with analogous Y and Gd alumino-borates. All materials have been prepared in the form of polycrystalline powders by solid state reaction. These three compounds have a trigonal structure with a R32 space group and the symmetry of each aluminium, lanthanide and boron site have been confirmed by MAS-NMR experiments. Main structural, thermal and fluorescence properties are given. The results show that in these compounds there are two sites of Ce 3+ and in the ultra violet range (maximum at 340 and 365 nm) Ce 3+ exhibits a 25 ns fluorescence. An extra-emission is observed in the low energy range. It could be originated from non-regular sites (aluminium and/or interstitial sites).

  7. Optical Properties of Cerium Doped Lutetium Borates : Characterization of Novel Scintillators

    NASA Astrophysics Data System (ADS)

    Salley, G. M.; Happek, U.; Yen, W. M.; Berdahl, P.; Derenzo, S. E.; Lewis, C.; Moses, W. W.; Perry, D.; Weber, M. J.

    1997-03-01

    In the search for fast, dense scintillator materials, cerium activated crystals attract special attention. Here we report on the characterization of a novel scintillator: lutetium borate (LuBO_3:Ce^3+). The synthesis of the scintillator involves firing of the starting materials in air, and depending on the thermal history of the synthesis, a calcite and a vaterite phase of the material can be obtained. We present the scintillation, absorption, and photoexcitation spectra of the two phases as well as time resolved measurements of the scintillation decay and compare the results with those of other cerium doped hosts. Finally, we report about our efforts to grow single crystals of the novel material, using laser heated pedestal growth technique.

  8. Czochralski growth of six Yb-doped double borate and silicate laser materials

    NASA Astrophysics Data System (ADS)

    Haumesser, Paul-Henri; Gaum, Romain; Benitez, Jean-Marie; Viana, Bruno; Ferrand, Bernard; Aka, Grard; Vivien, Daniel

    2001-11-01

    New Yb-doped oxides have been grown by the Czochralski method. They include borates such as Ca 3Y 2(BO 3) 4 (CYB), Ca 3Gd 2(BO 3) 4 (CaGB), Sr 3Y(BO 3) 3 (SrYBO) and Ba 3Lu(BO 3) 3 (BLuB) as well as the silicates Y 2SiO 5 (YSO), Ca 2Al 2SiO 7 (CAS) and SrY 4(SiO 4) 3O (SYS). Successful Czochralski growth is reported for the first time in the case of SrYBO. Scattering center free CAS single crystals were obtained as well. Spectroscopic evaluation reveals that all those materials should be suitable for diode pumping at 980 nm due to broad absorption lines, and operate in a quasi-3-level scheme with large crystal-field splitting of the Yb ground state manifold.

  9. On the Electron Paramagnetic Resonance Studies in Mixed Alkali Borate Glasses

    SciTech Connect

    Padmaja, G.; Reddy, T. Goverdhan; Kistaiah, P.

    2011-10-20

    Mixed alkali effect in oxide based glasses is one of the current research activity and studies on the behavior of spectroscopic parameters in these systems are quite important to understand the basic nature of this phenomenon. EPR studies of mixed alkali glasses Li{sub 2}O-K{sub 2}O-ZnO-B{sub 2}O{sub 3} doped with Fe{sup 3+} and Mn{sup 2+} were carried out at room temperature. The EPR spectra show typical resonances of d{sup 5} system (Fe{sup 3+} and Mn{sup 2+}) in all the measured glass specimens. Evaluated hyperfine constant, number of paramagnetic centers and paramagnetic susceptibility values show deviation from the linearity with the progressive substitution of the Li ion with K in glass network.

  10. Magnetic behavior of erbium-zinc-borate glasses and glass ceramics

    SciTech Connect

    Borodi, G.; Pascuta, P.; Bosca, M.; Pop, V.; Stefan, R.; Tetean, R.; Radulescu, D.

    2013-11-13

    Glasses of the system (Er{sub 2}O{sub 3}){sub x}⋅(B{sub 2}O{sub 3}){sub (60−x)}⋅(ZnO){sub 40} (3 ≤ x ≤ 15 mol%) were prepared by conventional melt quenching and subsequently converted to glass ceramics by heat treatment of glass samples at 860 °C for 2 h. The magnetic behaviour of the studied glasses and glass ceramics were investigated using a vibrating sample magnetometer (VSM) and a Faraday-type magnetic balance. Magnetic data show that erbium ions are involved in negative superexchange interactions in all the investigated samples, being antiferromagnetically coupled. For all studied samples the experimental values obtained for the effective magnetic moments are lower than the value corresponding to free Er{sup 3+} ions and decrease with the increasing of Er{sub 2}O{sub 3} content. The decrease is more pronounced in heat treated samples than untreated ones.

  11. Experimental insights on the electron transfer and energy transfer processes between Ce3+-Yb3+ and Ce3+-Tb3+ in borate glass

    NASA Astrophysics Data System (ADS)

    Sontakke, Atul D.; Ueda, Jumpei; Katayama, Yumiko; Dorenbos, Pieter; Tanabe, Setsuhisa

    2015-03-01

    A facile method to describe the electron transfer and energy transfer processes among lanthanide ions is presented based on the temperature dependent donor luminescence decay kinetics. The electron transfer process in Ce3+-Yb3+ exhibits a steady rise with temperature, whereas the Ce3+-Tb3+ energy transfer remains nearly unaffected. This feature has been investigated using the rate equation modeling and a methodology for the quantitative estimation of interaction parameters is presented. Moreover, the overall consequences of electron transfer and energy transfer process on donor-acceptor luminescence behavior, quantum efficiency, and donor luminescence decay kinetics are discussed in borate glass host. The results in this study propose a straight forward approach to distinguish the electron transfer and energy transfer processes between lanthanide ions in dielectric hosts, which is highly advantageous in view of the recent developments on lanthanide doped materials for spectral conversion, persistent luminescence, and related applications.

  12. Spectroscopic analysis of a novel Nd3+-activated barium borate glass for broadband laser amplification

    NASA Astrophysics Data System (ADS)

    Vázquez, G. V.; Muñoz H., G.; Camarillo, I.; Falcony, C.; Caldiño, U.; Lira, A.

    2015-08-01

    Spectroscopic parameters of a novel Nd3+-activated barium borate (BBONd) glass have been analyzed for broadband laser amplification. The Judd-Ofelt (JO) intensity parameters were determined through a systematic analysis of the absorption spectrum of Nd3+ ions in the BBONd glass. High values of the JO intensity parameters reveal a great centro-symmetrical loss of the Nd3+ sites and high covalency degree of the ligand field. The very high Ω6 intensity parameter value makes evident both a great structural distortion of the Nd3+ sites and a strong electron-phonon coupling between Nd3+ and free OH- ions, which is consistent with the phonon energy maximum (3442.1 cm-1) recorded by Raman spectroscopy. This strong electron-phonon coupling favors high effective bandwidth and gain bandwidth values of the laser emission (4F3/2 → 4I11/2) of Nd3+ ions. The electric-dipole oscillator strengths of all the Nd3+ absorption transitions, and in particular that of the hypersensitive transition (4I9/2 → 4G5/2), are enhanced by this great structural distortion of the host. Broadband laser amplification of the 4F3/2 → 4I11/2 emission (1062 nm) of Nd3+ ions in the BBONd glass pumped at 805 nm (4I9/2 → 4F5/2 + 2H9/2) is evaluated through the main fluorescent parameters in competition with non-radiative processes. In general, the BBONd glass exhibits spectroscopic parameters comparable with those reported in the literature for broadband laser amplification into the IR region.

  13. The Development of Doped Radiosensitive Glass

    SciTech Connect

    Bradley, D. A.; Okoya, O. O.; Hugtenburg, R. P.; Hashim, Suhairul; Ramli, A. T.; Wagiran, H.; Yusoff, A. L.; Hassan, A. Aziz Mat

    2007-05-09

    For a range of industrial and medical situations there exists need for sensitive, robust high spatial resolution systems for radiation measurements. Our overall focus is on the development of doped silica-glass thermoluminescent dosimeters (TLD) with a view towards improving upon the thermoluminescence (TL) yield of commercially produced optical fibers. In baseline studies of the latter, as detailed herein, measurements have been conducted using Ge-doped communication fibers, employing sources of irradiation including bremsstrahlung x-rays (produced by a nominal accelerating potential of 50 kVp), alpha particles from an 241Am source (predominant emission 5.486 MeV) and protons of energy 2.5 MeV provided by an ion beam source. Present studies, also including elemental analysis via the PIXE and RBS techniques, permit comparison with higher TL yield doped glasses previously made by this group via the sol-gel technique and characterized in part using a range of synchrotron techniques.

  14. Comparisons in Neutron Detection, as modeled by MCNPX, in Li-6 Glass, HE-3, BF-3, and Borated PVT

    SciTech Connect

    Lawrence Lakeotes, Craig Marianno

    2009-04-03

    With the potential shortage of He-3 being reported by venders, it is important to consider other materials for neutron detection. Traditional neutron detectors are composed of BF-3 and He-3. Recently Li-6 Glass and borated PVT have been presented as possible replacements. This work will compare the relative detection efficiencies and consider other factors to determine the most appropriate neutron detection material.

  15. Bone regeneration in rat calvarial defects implanted with fibrous scaffolds composed of a mixture of silicate and borate bioactive glasses.

    PubMed

    Gu, Yifei; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E

    2013-11-01

    Previous studies have evaluated the capacity of porous scaffolds composed of a single bioactive glass to regenerate bone. In the present study, scaffolds composed of a mixture of two different bioactive glasses (silicate 13-93 and borate 13-93B3) were created and evaluated for their response to osteogenic MLO-A5 cells in vitro and their capacity to regenerate bone in rat calvarial defects in vivo. The scaffolds, which have similar microstructures (porosity=58-67%) and contain 0, 25, 50 and 100 wt.% 13-93B3 glass, were fabricated by thermally bonding randomly oriented short fibers. The silicate 13-93 scaffolds showed a better capacity to support cell proliferation and alkaline phosphatase activity than the scaffolds containing borate 13-93B3 fibers. The amount of new bone formed in the defects implanted with the 13-93 scaffolds at 12 weeks was 31%, compared to values of 25, 17 and 20%, respectively, for the scaffolds containing 25, 50 and 100% 13-93B3 glass. The amount of new bone formed in the 13-93 scaffolds was significantly higher than in the scaffolds containing 50 and 100% 13-93B3 glass. While the 13-93 fibers were only partially converted to hydroxyapatite at 12 weeks, the 13-93B3 fibers were fully converted and formed a tubular morphology. Scaffolds composed of an optimized mixture of silicate and borate bioactive glasses could provide the requisite architecture to guide bone regeneration combined with a controllable degradation rate that could be beneficial for bone and tissue healing. PMID:23827095

  16. Low loss photonic components in high index bismuth borate glass by femtosecond laser direct writing.

    PubMed

    Yang, Weijia; Corbari, Costantino; Kazansky, Peter G; Sakaguchi, Koichi; Carvalho, Isabel C S

    2008-09-29

    Single mode, low loss waveguides were fabricated in high index bismuth borate glass by femtosecond laser direct writing. A specific set of writing parameters leading to waveguides perfectly mode matched to standard single-mode fibers at 1.55 microm with an overall insertion loss of approximately 1 dB and with propagation loss below 0.2 dB/cm was identified. Photonic components such as Y-splitters and directional couplers were also demonstrated. A close agreement between their performances and theoretical predictions based upon the characterization of the waveguide properties is shown. Finally, the nonlinear refractive index of the waveguides has been measured to be 6.6 x 10(-15) cm(2)/W by analyzing self-phase modulation of the propagating femtosecond laser pulse at the wavelength of 1.46 microm. Broadening of the transmitted light source as large as 500 nm was demonstrated through a waveguide with the length of 1.8 cm. PMID:18825261

  17. Structural and morphological transformations of BaTiO3 nanocrystals in thin layers of borate oxide glasses

    NASA Astrophysics Data System (ADS)

    Kedrov, V. V.; Shmyt'ko, I. M.

    2015-02-01

    The influence of thin layers (2-15 μm) of some oxide glass melts on BaTiO3 nanocrystallites has been investigated using X-ray diffractometry and scanning electron microscopy. It has been shown that lead borate and sodium borate glass melts bring about the dissolution of BaTiO3 nanocrystallites and the subsequent crystallization in glasses of lead titanate PbTiO3 and sodium titanate Na2TiO3, respectively. It has been found that thin layers of melts of these glasses have a strong orientation effect on crystallites of the PbTiO3 and Na2TiO3 compounds newly synthesized from barium titanate. The orientation effect exerted by these glass layers results in the formation of a pronounced texture of the perovskite crystallites with the texture axes oriented along the [100] and [001] directions parallel to the surface normal of the substrate for lead titanate and the orientation of the planes of the film surface for the sodium titanium oxide.

  18. Non-bridging oxygens in borate glasses: characterization by 11B and 17O MAS and 3QMAS NMR.

    PubMed

    Stebbins, J F; Zhao, P; Kroeker, S

    2000-05-01

    The concentrations of non-bridging oxygens (NBO) in oxide glasses has major effects on their properties and on those of their precursor glass melts. In borate and borosilicate glasses, the presence of NBO bonded to boron has generally been inferred from 11B NMR spectra and mass balance considerations. Here we report the direct observation of such NBO using 17O MAS and 3QMAS techniques, and compare estimates of their populations with those derived from high-resolution 11B MAS spectra. For the latter, two independent methods are used, based on the ratios of trigonal to tetrahedral boron and on the concentrations of trigonal boron sites with large quadrupolar asymmetry parameters. We include data on crystalline sodium pyroborate (Na4B2O5) and sodium metaborate (NaBO2), and several sodium and barium borate glasses. 17O chemical shifts and quadrupolar coupling constants for NBO bonded to boron vary considerably depending on their coordination environment. In borosilicates, peaks for this species may be hidden by overlap with B-O-Si or Si-O-Si resonances. PMID:10811425

  19. Characterization of the glass-to-vitroceramic transition in yttrium aluminum borate laser glasses using solid state NMR.

    PubMed

    Deters, Heinz; Eckert, Hellmut

    2012-02-01

    The crystallization of laser glasses in the system (Y(2)O(3))(0.2){((Al(2)O(3))(x))(B(2)O(3))(0.8-x)} (0.15 ≤ x ≤ 0.40) doped with 0.5 mol% of ytterbium oxide has been investigated by x-ray powder diffraction, and various solid state NMR techniques. The crystallization process has been analyzed in a quantitative fashion by high-resolution solid state (11)B, (27)Al, and (89)Y NMR spectroscopy as well as (11)B{(27)Al} and (27)Al{(11)B} rotational echo double resonance (REDOR) experiments. The homogeneous glasses undergo major phase segregation processes resulting in crystalline Al(5)BO(9) (historically denoted as Al(18)B(4)O(33)), YBO(3), crystalline YAl(3)(BO(3))(4), residual glassy B(2)O(3), and an additional yet not identified crystalline phase ("X-phase"). PMID:22244244

  20. LITHIUM-7, BORON-10, BORON-11, and OXYGEN-17 Nuclear Magnetic Resonance Studies of Lithium Borate Glasses and Related Compounds.

    NASA Astrophysics Data System (ADS)

    Feller, Steven Allen

    1980-06-01

    Nuclear Magnetic Resonance (NMR) studies of lithium borate glasses employing the two stable isotopes of boron, B('10) and B('11), were used in the formulation of a consistent structural model throughout the glass-forming region. The ideas of Krogh-Moe were used in which the glasses are viewed as mixtures of units found in corresponding crystalline compounds. For low-alkali oxide content glasses the results are in good agreement with those obtained by Jellison and Bray in sodium borate glasses. These glasses are viewed as being mixtures of boroxol, tetraborate and diborate units. Intermediate-alkali oxide content glasses satisfy a model proposed in this thesis in which diborate and tetraborate units are destroyed to form loose N('4) and metaborate units. For high-alkali oxide content glasses the results are in good agreement with a model proposed by Yun and Yun and Bray in which loose N('4), metaborate, pyroborate and orthoborate units exist. Li(,2)O, enriched in O('17), was synthesized in such a way that H(,2)O enriched to 54% O('17) was efficiently transferred into Li(,2)O. It is hypothesized that the synthesis of Li(,2)O enriched in O('17) as well as the synthesis of the other alkali oxides (e.g. Na(,2)O, K(,2)O, Rb(,2)O and Cs(,2)O) will greatly enlarge the range of O('17) NMR studies of glasses and related compounds. Li('7) and O('17) NMR studies of Li(,2)O revealed structureless derivative spectra of linewidths 9.9 gauss and 5.8 gauss, respectively. These experimental results were compared to a second-moment calculation of the linewidths using the anti-fluorite crystal structure for Li(,2)O. O('17) NMR studies of two lithium borate compounds, lithium metaborate (Li(,2)O(.)B(,2)O(,3)) and lithium orthoborate (3Li(,2)O(.)B(,2)O(,3)) were used to identify the quadrupole parameters of bridging and non-bridging oxygen atoms. These results, in conjunction with B('11) NMR results from these compounds, were used to determine charge densities associated with the boron and oxygen atoms by means of the simplifying approximations of Townes and Dailey.

  1. Electronic polarizability and interaction parameter of gadolinium tungsten borate glasses with high WO{sub 3} content

    SciTech Connect

    Taki, Yukina; Shinozaki, Kenji; Honma, Tsuyoshi; Dimitrov, Vesselin; Komatsu, Takayuki

    2014-12-15

    Glasses with the compositions of 25Gd{sub 2}O{sub 3}–xWO{sub 3}–(75−x)B{sub 2}O{sub 3} with x=25–65 were prepared by using a conventional melt quenching method, and their electronic polarizabilities, optical basicities Λ(n{sub o}), and interaction parameters A(n{sub o}) were estimated from density and refractive index measurements in order to clarify the feature of electronic polarizability and bonding states in the glasses with high WO{sub 3} contents. The optical basicity of the glasses increases monotonously with the substitution of WO{sub 3} for B{sub 2}O{sub 3}, and contrary the interaction parameter decreases monotonously with increasing WO{sub 3} content. A good linear correlation was observed between Λ(n{sub o}) and A(n{sub o}) and between the glass transition temperature and A(n{sub o}). It was proposed that Gd{sub 2}O{sub 3} oxide belongs to the category of basic oxide with a value of A(n{sub o})=0.044 Å{sup −3} as similar to WO{sub 3}. The relationship between the glass formation and electronic polarizability in the glasses was discussed, and it was proposed that the glasses with high WO{sub 3} and Gd{sub 2}O{sub 3} contents would be a floppy network system consisting of mainly basic oxides. - Graphical abstract: This figure shows the correlation between the optical basicity and interaction parameter in borate-based glasses. The data obtained in the present study for Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses are locating in the correlation line for other borate glasses. These results shown in Fig. 8 clearly demonstrate that Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses having a wide range of optical basicity and interaction parameter are regarded as glasses consisting of acidic and basic oxides. - Highlights: • Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses with high WO{sub 3} contents were prepared. • Electronic polarizability and interaction parameter were estimated. • Optical basicity increases monotonously with increasing WO{sub 3} content. • Interaction parameter decreases monotonously with increasing WO{sub 3} content. • Glasses with high WO{sub 3}contents is regarded as a floppy network system.

  2. Thermal lensing effects in ?-doped ? luminescent glass

    NASA Astrophysics Data System (ADS)

    Alvarez, E. R.; Camarillo, I. G.; Castao, E. T.; Muoz, A. F.; Clark, A. B.; Taheri, B.

    1996-07-01

    Optical absorption, photoluminescence and fluorescence decay time of 0953-8984/8/30/013/img10 in a 0953-8984/8/30/013/img11 glass were measured in the 400 - 800 nm range. Under continuous (CW) laser excitation the characteristics of thermal lensing (TL) were measured at room temperature, under resonant and non-resonant conditions. Our results are analysed based on a theoretical model for CW laser induced thermal lensing under a gaussian-beam approximation. The effects of the power input and the response time for TL are explained in terms of the thermal properties of the glass host, for non-resonant excitation, and in terms of the coupling of rare earth ions to the local vibrations for resonant excitations. We also report, for the first time, the observation of laser induced permanent changes in the refractive index of bulk rare earth doped oxide glasses, under non-resonant excitation conditions.

  3. Characterisation of Erbium Doped Phosphate Glass

    SciTech Connect

    Rasid, A. A.; Rohani, M. S.; Sahar, M. R.; Kasim, A.

    2010-03-11

    A series of erbium doped phosphate glass has been successfully fabricated, and the determination of their density and luminescence properties has been carried out. It is particularly interesting to study the effect of modifying oxides to the properties of the glass. The glass density reduces with the increasing content of Na{sub 2}O. The emission spectra from luminescence spectroscopy resolved six emission peaks from the excitation wavelength of 336.8 nm (3.69 eV). The emission of {sup 4}F{sub 7/2} gives two emission peaks, where the peak near 482 nm shows a higher intensity and the peak near 491 nm gives a weak emission spectra.

  4. The effect of semiconducting CdSe and ZnSe nanoparticles on the fluorescence of Sm3+ in lead borate glasses

    NASA Astrophysics Data System (ADS)

    Mallur, Saisudha; Fatokun, Stephen; Babu, P. K.

    2015-03-01

    We studied the fluorescence spectra of Sm3+ doped lead borate glasses containing zinc selenide (ZnSe) and cadmium selenide (CdSe) nanoparticles with the following compositions (x PbO: 96.5-x B2O3:0.5 Sm2O3:3ZnSe/CdSe, x =36.5 and 56.5 mol%). These glass samples are prepared using the melt-quenching technique. Each sample is annealed just below the glass transition temperature at 400°C for 3 hrs and 6 hrs. We have chosen PbO-B2O3 glasses to incorporate Sm3+ ions because they have large glass forming region, high refractive index, and good physical and thermal stability. Fluorescence spectra of these samples are obtained with the excitation wavelength at 477 nm. Four fluorescence transitions are observed at 563 nm, 598 nm, 646 nm and 708 nm. The transition at 646 nm is found to be a hypersensitive transition that strongly depends on the covalency of the Sm-O bond and the asymmetry of the crystal field at Sm site. The 646 nm/598 nm fluorescence intensity ratio has been studied for different annealing times and PbO concentration for both ZnSe and CdSe samples. The presence of CdSe nanoparticles is seen to produce the greatest influence on the fluorescence intensity ratio. This could be due to the size of the CdSe nanoparticles and covalency of the Sm-O bond.

  5. Copper oxide content dependence of crystallization behavior, glass forming ability, glass stability and fragility of lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Soliman, A. A.; Kashif, I.

    2010-01-01

    Differential thermal analysis (DTA) and X-ray diffraction (XRD) have been employed to investigate the copper oxide content dependence of the glass transition temperatures data, activation energy for the glass transition Et, glass stability GS, fragility index Fi, the glass-forming ability (GFA) and crystallization behavior of {(100- x) mol% Li 2B 4O 7- x mol% CuO} glass samples, where x=0-40 mol% CuO. From the dependence of the glass transition temperature Tg on the heating rate β, the fragility, Fi, and the activation energy, Et, have been calculated. It is seen that Fi and Et are attained their minimum values at 0glass-forming ability and the supercooled liquid region SCL. Thermal stability has been monitored through the calculation of the temperature difference T x- Tg, SCL region and the GS. The GFA has been investigated on the basis of Hrubÿ parameter KH, which is a strong indicator of GFA, and the relaxation time. Results of GFA are in good agreement with the fragility index, Fi, calculations indicating that {90Li 2B 4O 7·10CuO} is the best glass former. The stronger glass forming ability has decreasing the fragility index. XRD result indicates that no fully amorphous samples but a mixture of crystalline and amorphous phases are formed in the samples containing x>25 mol% CuO and below it composed of glassy phase. Increasing the CuO content above 25 mol% helps the crystallization process, and thus promotes a distinct SCL region. XRD suggests the presence of micro-crystallites of remaining residual amorphous matrix by increasing the CuO content.

  6. Teicoplanin-loaded borate bioactive glass implants for treating chronic bone infection in a rabbit tibia osteomyelitis model.

    PubMed

    Zhang, Xin; Jia, Weitao; Gu, Yifei; Xiao, Wei; Liu, Xin; Wang, Deping; Zhang, Changqing; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E; Zhou, Nai

    2010-08-01

    The treatment of chronic osteomyelitis (bone infection) remains a clinical challenge. In this work, pellets composed of a chitosan-bonded mixture of borate bioactive glass particles (<50microm) and teicoplanin powder (antibiotic), were evaluated in vitro and in vivo for treating chronic osteomyelitis induced by methicillin-resistant Staphylococcus aureus (MRSA) in a rabbit model. When immersed in phosphate-buffered saline, the pellets showed sustained release of teicoplanin over 20-30 days, while the bioactive glass converted to hydroxyapatite (HA) within 7 days, eventually forming a porous HA structure. Implantation of the teicoplanin-loaded pellets in a rabbit tibia osteomyelitis model resulted in the detection of teicoplanin in the blood for about 9 days. The implants converted to a bone-like HA graft, and supported the ingrowth of new bone into the tibia defects within 12 weeks of implantation. Microbiological, histological and scanning electron microscopy techniques showed that the implants provided a cure for the bone infection. The results indicate that the teicoplanin-loaded borate bioactive glass implant, combining sustained drug release with the ability to support new bone ingrowth, could provide a method for treating chronic osteomyelitis. PMID:20434766

  7. Structure of Alkali Borate Glasses at High Pressure: B and Li K-Edge Inelastic X-Ray Scattering Study

    SciTech Connect

    Lee, Sung Keun; Eng, Peter J.; Mao, Ho-kwang; Meng, Yue; Shu, Jinfu

    2008-06-16

    We report the first in situ boron K-edge inelastic x-ray scattering (IXS) spectra for alkali borate glasses (Li{sub 2}B{sub 4}O{sub 7}) at high pressure up to 30 GPa where pressure-induced coordination transformation from three-coordinated to four-coordinated boron was directly probed. Coordination transformation (reversible upon decompression) begins around 5 GPa and the fraction of four-coordinated boron increases with pressure from about 50% (at 1 atm) to more than 95% (at 30 GPa) with multiple densification mechanisms, evidenced by three distinct pressure ranges for (d{sup [4]}B/dP){sub T}. The lithium K-edge IXS spectrum for Li-borate glasses at 5 GPa shows IXS features similar to that at 1 atm, suggesting that the Li environment does not change much with pressure up to 5 GPa. These results provide improved understanding of the structure of low-z glass at high pressure.

  8. Defect formation of gamma irradiated MoO3-doped borophosphate glasses.

    PubMed

    Abdelghany, A M; Ouis, M A; Azooz, M A; Ellbatal, H A

    2013-10-01

    Borophosphate glasses of the basic composition (50P2O5, 30B2O3, 20Na2O mol%) containing different doping molybdenum oxide percents (0.16-0.98) were prepared by melting and annealing method. Infrared and UV-visible absorption spectroscopic measurements before and after gamma irradiation were carried out. The base undoped borophosphate glass reveals strong UV absorption bands but with no visible bands and these UV bands are related to unavoidable trace iron impurities contaminated within the raw materials used for the preparation of this glass. The introduction of MoO3 (in doping ratio) into this glass produces an additional UV band and a broad visible band and their intensities increase with the MoO3 content. These additional bands are related to both Mo(6+) and Mo(5+) ions. The base undoped borophosphate glass shows retardation effect towards gamma irradiation. Gamma irradiation produces marked changes in the UV-visible spectra of Mo-O3-doped glasses. Such changes can be related to the production of induced defects from photochemical reactions and the generation of positive holes. Infrared absorption spectrum of the undoped borophosphate glass reveals complex vibrational bands due to the presence of both phosphate groups beside borate groups with triangular and tetrahedrally coordinated units. The introduction of MoO3 causes some limited variations in the FTIR spectra. Gamma irradiation produces minor changes in the intensities of some IR bands. Such changes are related to the changes in the bond angles and/or bond lengths of few structural groups upon irradiation while the main structural groups remain unchanged in their number and position. PMID:23800775

  9. Optical properties of Er(3+)-doped oxyfluoride glasses.

    PubMed

    Feng, Li; Wu, Yinsu

    2016-02-15

    Er(3+)-singly doped and Er(3+)/Yb(3+)-codoped 50SiO2-(50-x)BaF2-xZnF2(SBZx) oxyfluoride glasses are prepared and the optical properties of Er(3+)-singly doped glasses are investigated by using the Judd-Ofelt theory. Bright green and red upconversion luminescence of Er(3+)/Yb(3+)-codoped glasses is obtained under 980nm excitation. Furthermore, factors affecting this phenomenon such as glass composition, doping concentration of Er(3+) and Yb(3+) ions, and pump power are discussed in details. PMID:26613336

  10. Optical properties of Er3 +-doped oxyfluoride glasses

    NASA Astrophysics Data System (ADS)

    Feng, Li; Wu, Yinsu

    2016-02-01

    Er3 +-singly doped and Er3 +/Yb3 +-codoped 50SiO2-(50 - x)BaF2-xZnF2(SBZx) oxyfluoride glasses are prepared and the optical properties of Er3 +-singly doped glasses are investigated by using the Judd-Ofelt theory. Bright green and red upconversion luminescence of Er3 +/Yb3 +-codoped glasses is obtained under 980 nm excitation. Furthermore, factors affecting this phenomenon such as glass composition, doping concentration of Er3 + and Yb3 + ions, and pump power are discussed in details.

  11. Role of electron transfer in Ce{sup 3+} sensitized Yb{sup 3+} luminescence in borate glass

    SciTech Connect

    Sontakke, Atul D. Katayama, Yumiko; Zhuang, Yixi; Tanabe, Setsuhisa; Ueda, Jumpei; Dorenbos, Pieter

    2015-01-07

    In a Ce{sup 3+}-Yb{sup 3+} system, two mechanisms are proposed so far namely, the quantum cutting mechanism and the electron transfer mechanism explaining Yb{sup 3+} infrared luminescence under Ce{sup 3+} excitation. Among them, the quantum cutting mechanism, where one Ce{sup 3+} photon (ultraviolet/blue) gives rise to two Yb{sup 3+} photons (near infrared) is widely sought for because of its huge potential in enhancing the solar cell efficiency. In present study on Ce{sup 3+}-Yb{sup 3+} codoped borate glasses, Ce{sup 3+} sensitized Yb{sup 3+} luminescence at ∼1 μm have been observed on Ce{sup 3+} 5d state excitation. However, the intensity of sensitized Yb{sup 3+} luminescence is found to be very weak compared to the strong quenching occurred in Ce{sup 3+} luminescence in Yb{sup 3+} codoped glasses. Moreover, the absolute luminescence quantum yield also showed a decreasing trend with Yb{sup 3+} codoping in the glasses. The overall behavior of the luminescence properties and the quantum yield is strongly contradicting with the quantum cutting phenomenon. The results are attributed to the energetically favorable electron transfer interactions followed by Ce{sup 3+}-Yb{sup 3+} ⇌ Ce{sup 4+}-Yb{sup 2+} inter-valence charge transfer and successfully explained using the absolute electron binding energies of dopant ions in the studied borate glass. Finally, an attempt has been presented to generalize the electron transfer mechanism among opposite oxidation/reduction property dopant ions using the vacuum referred electron binding energy (VRBE) scheme for lanthanide series.

  12. Effect of Co(2+) and Ni(2+)-doped zinc borate nano crystalline powders by co-precipitation method.

    PubMed

    Shim, Jaesool; Venkata Reddy, Ch; Sarma, G V S S; Narayana Murthy, P; Ravikumar, R V S S N

    2015-05-01

    A simple co-precipitation method has been used for the synthesis of Co(2+) and Ni(2+)-doped zinc borate nanopowders. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV/Vis absorption, Scanning electron microscope (SEM) with EDS and photoluminescence (PL) spectroscopies techniques has been employed for their characterization. Powder X-ray diffraction data reveals that the crystal structure belongs to monoclinic for both as-prepared samples. SEM images showed surface morphology of the prepared samples. Optical absorption spectra showed the characteristic bands of doped ions in octahedral site symmetry. From the optical absorption data crystal field and inter-electronic repulsion parameters are evaluated. The FT-IR spectra showed the characteristic vibrational bands related to ZnO, BO3 and BO4 molecules. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions. PMID:25706597

  13. Effect of Co2+ and Ni2+-doped zinc borate nano crystalline powders by co-precipitation method

    NASA Astrophysics Data System (ADS)

    Shim, Jaesool; Venkata Reddy, Ch.; Sarma, G. V. S. S.; Narayana Murthy, P.; Ravikumar, R. V. S. S. N.

    2015-05-01

    A simple co-precipitation method has been used for the synthesis of Co2+ and Ni2+-doped zinc borate nanopowders. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV/Vis absorption, Scanning electron microscope (SEM) with EDS and photoluminescence (PL) spectroscopies techniques has been employed for their characterization. Powder X-ray diffraction data reveals that the crystal structure belongs to monoclinic for both as-prepared samples. SEM images showed surface morphology of the prepared samples. Optical absorption spectra showed the characteristic bands of doped ions in octahedral site symmetry. From the optical absorption data crystal field and inter-electronic repulsion parameters are evaluated. The FT-IR spectra showed the characteristic vibrational bands related to ZnO, BO3 and BO4 molecules. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions.

  14. IR luminescence in bismuth-doped germanate glasses and fibres

    SciTech Connect

    Pynenkov, A A; Firstov, Sergei V; Panov, A A; Firstova, E G; Nishchev, K N; Bufetov, Igor' A; Dianov, Evgenii M

    2013-02-28

    We have studied the optical properties of lightly bismuth doped ({<=}0.002 mol %) germanate glasses prepared in an alumina crucible. The glasses are shown to contain bismuth-related active centres that have been identified previously only in bismuth-doped fibres produced by MCVD. With increasing bismuth concentration in the glasses, their luminescence spectra change markedly, which is attributable to interaction between individual bismuth centres. (optical fibres)

  15. Effect of B2O3 on luminescence of erbium doped tellurite glasses.

    PubMed

    Shen, Xiang; Nie, Qiuhua; Xu, Tiefeng; Dai, Shixun; Wang, Xunsi

    2007-02-01

    The B2O3 was introduced into the Er3+ doped TeO2-ZnO-Na2O glass to increase the phonon energy of the host. The effect of B2O3 on the non-radiative rate of the 4I11/2-->4I13/2 transition of Er3+, the lifetime of the 4I11/2 and 4I13/2 levels, the green and red upconversion emissions intensity, and the 4I13/2-->4I15/2 emission intensity was discussed. The results show that the phonon energy of boro-tellurite glass is close to that of germanate glass and is quite smaller than that of borate glass. The lifetime of 4I11/2 level and the upconversion emissions decrease with increasing B2O3 concentration. The higher OH group concentration presented in the boro-tellurite glass may shorten the lifetime of 4I13/2 level and also reduce the quantum efficiency of 4I13/2-->4I15/2 emission. The future dehydrating procedures are suggested to enhance the efficiency of amplification at 1.5 microm band. PMID:16843711

  16. Influence of modifier oxides on spectroscopic properties of Sm3+ doped lithium fluoroborate glass

    NASA Astrophysics Data System (ADS)

    Ratnakaram, Y. C.; Balakrishna, A.; Rajesh, D.; Seshadri, M.

    2012-11-01

    Sm3+ doped lithium fluoro-borate glasses with different modifier oxides (Li2B4O7-BaF2-NaF-MO where M = Mg, Ca, Cd and Pb) and combinations of modifier oxides (Li2B4O7-BaF2-NaF-MgO+CaO, Li2B4O7-BaF2-NaF-CdO+PbO) were prepared by means of melt quenching method. These samples were characterized by XRD, FTIR, optical absorption and fluorescence techniques at room temperature. The XRD profiles of all the glasses confirm their amorphous nature and the FTIR spectra reveal the presence of BO3 and BO4 units along with the strong OH- groups in the glass matrices. The influence of modifier oxides on Judd-Ofelt (J-O) intensity parameters and intensity of the emission lines are reported. Judd-Ofelt theory is used to study the spectral properties and to calculate the radiative transition probabilities (AT), branching ratios (βR), integrated absorption cross sections (Σ) and radiative lifetimes (τR) for certain spectral transitions. From the emission spectral analysis, emission cross-sections (σP) are calculated for the four emission transitions, 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 of Sm3+ ion in different lithium fluoro-borate glasses. Among the four transitions, it is observed that the transition 4G5/2 → 6H7/2 has higher emission cross-section (σP) in all the glass matrices, except in Mg, Cd and Mg-Ca glass matrices. The non-exponential nature of the luminescence decay curves of 4G5/2 level of Sm3+ doped glass matrices are also reported.

  17. Effect of pyrophosphate ions on the conversion of calciumlithiumborate glass to hydroxyapatite in aqueous phosphate solution

    PubMed Central

    Fu, Hailuo; Day, Delbert E.; Huang, Wenhai

    2010-01-01

    The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calciumlithiumborate glass to HA was investigated. Particles of the glass (150355 m) were immersed for up to 28 days in 0.25 M K2HPO4 solution containing 00.1 M K4P2O7. The kinetics of degradation of the glass particles and their conversion to HA were monitored by measuring the weight loss of the particles and the ionic concentration of the solution. The structure and composition of the conversion products were analyzed using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. For K4P2O7 concentrations of up to 0.01 M, the glass particles converted to HA, but the time for complete conversion increased from 2 days (no K4P2O7) to 10 days (0.01 M K4P2O7). When the K4P2O7 concentration was increased to 0.1 M, the product consisted of an amorphous calcium phosphate material, which eventually crystallized to a pyrophosphate product (predominantly K2CaP2O7 and Ca2P2O7). The consequences of the results for the formation of HA materials and devices by the glass conversion route are discussed. PMID:20680413

  18. Effect of zinc-borate glass addition on the thermal properties of the cordierite/Al2O3 composites containing nano-sized spinel crystal.

    PubMed

    Jo, Sinae; Kang, Seunggu

    2013-11-01

    Low-melting zinc-borate glass was added to the cordierite/Al2O3 composite in order to improve the sintering facility of Al2O3 and formation of nano-sized spinel crystal of high thermal conductivity. Increasing the ZnO/B2O3 ratio in the zinc-borate glass increased the ZnAl2O4 spinel and decreased the Al4B2O9 crystal peak intensities in X-ray diffraction pattern. The XRD peak intensities of the ZnAl2O4 spinel and Al4B2O9 crystals in the specimen containing 10 wt% zinc-borate glass (10G series) are higher than that of the specimen containing 5 wt% zinc-borate glass (5G series). The microstructures of most 10G series specimens had the flower-shaped crystal which was composed of 50 nm wide and 250 nm long needle-like crystals and identified as ZnAl2O4 spinel phase. The thermal conductivity of the 10G series specimen was higher than that of the 5G series in any ZnO/B2O3 ratio due to the formation of plenty of nano-sized ZnAl2O4 spinel of high thermal conductivity. Particularly, the thermal conductivity of the cordierite/Al2O3 composite containing 10 wt% zinc-borate glass of ZnO/B2O3 weight ratio = 1.5 was 3.8 W/Km which is much higher than that of the published value (3.0 W/Km). PMID:24245313

  19. Excited state absorption in Mn2+ doped phosphate glass

    NASA Astrophysics Data System (ADS)

    Jethwa, J.; Schfer, F. P.; Reisfeld, R.

    1990-03-01

    The possibility of obtaining laser action from Mn2+ doped glass has been investigated. The excited state absorption at the expected laser wavelength was measured and explains the unsuccessful attempts to obtain laser action.

  20. Photon-conversion and sensitization evaluation of Eu3+ in a borate glass system.

    PubMed

    Tian, Y M; Shen, L F; Pun, E Y B; Lin, H

    2016-02-20

    Photon conversion is exhibited in a borate (LKZBSB) glass system containing Eu3+, and the enhanced characteristic emissions of Eu3+ with the codoping of Ce3+ have been verified. A large Judd-Ofelt intensity parameter Ω2 of Eu3+ indicates a high asymmetrical and strong covalent environment around rare-earth (RE) ions in LKZBSB glasses and spontaneous emission probability and a maximum emission cross section of the dominant D50→F27 transition were derived to be 370  s-1 and 1.28×10-21  cm2, respectively, revealing the potential UV→visible photon-conversion capacity of Eu3+. Absolutely quantitative evaluation illustrates that Eu3+ is a favorable photon-conversion center to achieve high photon-conversion efficiency. The addition of Ce3+ is beneficial to realizing effective red emission of Eu3+, which possesses commercial value by decreasing the dopant of expensive europium compounds. As an expectation, this photon-conversion LKZBSB glass system can promote the development of a photon downconversion layer for solar cells, which are particularly used in outer space with intense UV radiation. PMID:26906599

  1. Bioactive borate glass scaffolds: in vitro and in vivo evaluation for use as a drug delivery system in the treatment of bone infection.

    PubMed

    Liu, Xin; Xie, Zongping; Zhang, Changqing; Pan, Haobo; Rahaman, Mohamed N; Zhang, Xin; Fu, Qiang; Huang, Wenhai

    2010-02-01

    The objective of this work was to evaluate borate bioactive glass scaffolds (with a composition in the system Na(2)O-K(2)O-MgO-CaO-B(2)O(3)-P(2)O(5)) as devices for the release of the drug Vancomycin in the treatment of bone infection. A solution of ammonium phosphate, with or without dissolved Vancomycin, was used to bond borate glass particles into the shape of pellets. The in vitro degradation of the pellets and their conversion to a hydroxyapatite-type material in a simulated body fluid (SBF) were investigated using weight loss measurements, chemical analysis, X-ray diffraction, and scanning electron microscopy. The results showed that greater than 90% of the glass in the scaffolds degraded within 1 week, to form poorly crystallized hydroxyapatite (HA). Pellets loaded with Vancomycin provided controlled release of the drug over 4 days. Vancomycin-loaded scaffolds were implanted into the right tibiae of rabbits infected with osteomyelitis. The efficacy of the treatment was assessed using microbiological examination and histology. The HA formed in the scaffolds in vivo, resulting from the conversion of the glass, served as structure to support the growth of new bone and blood vessels. The results in this work indicate that bioactive borate glass could provide a promising biodegradable and bioactive material for use as both a drug delivery system and a scaffold for bone repair. PMID:19830527

  2. Structural and optical properties of Dy3+ doped Aluminofluoroborophosphate glasses for white light applications

    NASA Astrophysics Data System (ADS)

    Vijayakumar, M.; Mahesvaran, K.; Patel, Dinesh K.; Arunkumar, S.; Marimuthu, K.

    2014-11-01

    Dy3+ doped Aluminofluoroborophosphate glasses (BPAxD) have been prepared following conventional melt quenching technique and their structural and optical properties were explored through XRD, FTIR, optical absorption, excitation, emission and decay measurements. The coexistence of BO3 groups in borate rich domain and BO4 groups in phosphate rich domain have been confirmed through vibrational energy analysis. Negative bonding parameter (?) values indicate that, the metal-ligand environment in the prepared glasses is of ionic in nature. The oscillator strength and the luminescent intensity ?? (? = 2, 4 and 6) parameters are calculated using Judd-Ofelt theory. The radiative properties such as transition probability (A), stimulated emission cross-section (?pE) and branching ratios (?) have been calculated using JO intensity parameters and compared with the reported Dy3+ doped glasses. Concentration effect on Y/B intensity ratios and the CIE chromaticity coordinates were calculated for the generation of white light from the luminescence spectra. The color purity and the correlated color temperature were also calculated and the results are discussed in the present work. The decay of the 4F9/2 excited level is found to be single exponential for lower concentration and become non-exponential for higher concentration. The non-exponential behavior arises due to the efficient energy transfer between the Dy3+ ions through various non-radiative relaxation channels and the decay of the 4F9/2 excited level have been analyzed with IH model. Among the prepared glasses, BPA0.5D glass exhibits higher ?pE, ?R, ?pE?pE, ?pE??eff and ? values for the 6H13/2 emission band which in turn specifies its suitability for white LEDs, laser applications and optical amplifiers.

  3. Probing and modeling of pressure-induced coordination transformation in borate glasses: Inelastic x-ray scattering study at high pressure

    SciTech Connect

    Lee, Sung Keun; Eng, Peter J.; Mao, Ho-kwang; Shu, Jinfu

    2009-01-15

    Here, we report on the in situ synchrotron inelastic x-ray scattering spectra of Na-borate glasses at high pressure up to 25 GPa. The pressure-induced boron coordination transformation from {sup [3]}B to {sup [4]}B is linear with pressure characterized by a single value of ({partial_derivative}{sup [3]}B/{partial_derivative}P){sub T}. Previous studies of Li-borate and pure-borate glasses show a nonlinear transformation with multiple ({partial_derivative}{sup [3]}B/{partial_derivative}P){sub T} values for different pressure ranges, revealing the important role cation field strength plays in densification and pressure-induced structural changes. Considering the distribution of the energy difference beween low- and high-pressure states ({Delta}{var_epsilon}) in the energy landscape and the variance of the ratio {Delta}{var_epsilon} to its pressure gradient ({partial_derivative}{Delta}{var_epsilon}/{partial_derivative}P){sub T} as a measure of network flexibility with pressure, an amorphous system with a large variance in {Delta}{var_epsilon} at 1 atm and/or a small ({partial_derivative}{Delta}{var_epsilon}/{partial_derivative}P){sub T} may undergo a gradual coordination transformation (e.g., Na borates). In contrast, a system with the opposite behavior (e.g., Li borates) undergoes an abrupt coordination transformation. The results and concepts of this study thus can shed light on opportunities to study the effect of composition on the nature of densification in low-z oxide and other archetypal glasses and melts.

  4. Gamma rays interaction with copper doped lithium phosphate glasses

    NASA Astrophysics Data System (ADS)

    ElBatal, Hatem A.; ElMandouh, Zeinab E.; Zayed, Hamdia A.; Marzouk, Samir Y.; Elkomy, Gihan M.; Hosny, Ahmed

    2013-12-01

    Undoped and copper-doped lithium phosphate glasses were prepared. CuO-doped glasses possess characteristic greenish color which deepens with the increase of CuO content. Experimental optical absorption spectra of the undoped lithium phosphate glasses reveal strong ultraviolet absorption bands and no visible bands are observed. These strong UV bands are assumed to originate from unavoidable trace iron ions contamination within the chemicals used for the preparation of the glass. The optical absorption spectra of the CuO-doped phosphate glasses reveal the same UV absorption as observed in the undoped samples beside an extra broad visible absorption band which splits to some component peaks. Such visible spectra are related to the presence of divalent copper (Cu2+) ions in distorted octahedral coordination. Gamma irradiation of the undoped sample produces induced defects generated through the liberation of pairs of electrons and positive holes. CuO-doped glasses show some shielding behavior towards successive gamma irradiation especially at high CuO contents. FTIR absorption spectra of the studied glasses indicate the appearance of characteristic vibrational bands due to phosphate groups. Gamma irradiation causes minor effects on the FTIR spectra, but the bands due to water molecules are strongly affected by gamma irradiation because of loose bonding within the glass network.

  5. Experimental insights on the electron transfer and energy transfer processes between Ce{sup 3+}-Yb{sup 3+} and Ce{sup 3+}-Tb{sup 3+} in borate glass

    SciTech Connect

    Sontakke, Atul D. Katayama, Yumiko; Tanabe, Setsuhisa; Ueda, Jumpei; Dorenbos, Pieter

    2015-03-30

    A facile method to describe the electron transfer and energy transfer processes among lanthanide ions is presented based on the temperature dependent donor luminescence decay kinetics. The electron transfer process in Ce{sup 3+}-Yb{sup 3+} exhibits a steady rise with temperature, whereas the Ce{sup 3+}-Tb{sup 3+} energy transfer remains nearly unaffected. This feature has been investigated using the rate equation modeling and a methodology for the quantitative estimation of interaction parameters is presented. Moreover, the overall consequences of electron transfer and energy transfer process on donor-acceptor luminescence behavior, quantum efficiency, and donor luminescence decay kinetics are discussed in borate glass host. The results in this study propose a straight forward approach to distinguish the electron transfer and energy transfer processes between lanthanide ions in dielectric hosts, which is highly advantageous in view of the recent developments on lanthanide doped materials for spectral conversion, persistent luminescence, and related applications.

  6. Optical and infrared absorption spectra of 3d transition metal ions-doped sodium borophosphate glasses and effect of gamma irradiation.

    PubMed

    Abdelghany, A M; ElBatal, F H; Azooz, M A; Ouis, M A; ElBatal, H A

    2012-12-01

    Undoped and transition metals (3d TM) doped sodium borophosphate glasses were prepared. UV-visible absorption spectra were measured in the region 200-900nm before and after gamma irradiation. Experimental optical data indicate that the undoped sodium borophosphate glass reveals before irradiation strong and broad UV absorption and no visible bands could be identified. Such UV absorption is related to the presence of unavoidable trace iron impurities within the raw materials used for preparation of this base borophosphate glass. The TMs-doped glasses show absorption bands within the UV and/or visible regions which are characteristic to each respective TM ion in addition to the UV absorption observed from the host base glass. Infrared absorption spectra of the undoped and TMs-doped glasses reveal complex FTIR consisting of extended characteristic vibrational bands which are specific for phosphate groups as a main constituent but with the sharing of some vibrations due to the borate groups. This criterion was investigated and approved using DAT (deconvolution analysis technique). The effects of different TMs ions on the FTIR spectra are very limited due to the low doping level (0.2%) introduced in the glass composition. Gamma irradiation causes minor effect on the FTIR spectra specifically the decrease of intensities of some bands. Such behavior is related to the change of bond angles and/or bond lengths of some structural building units upon gamma irradiation. PMID:22995547

  7. Optical absorption and fluorescence properties of Er{sup 3+}/Yb{sup 3+} codoped lead bismuth alumina borate glasses

    SciTech Connect

    Goud, K. Krishna Murthy Reddy, M. Chandra Shekhar Rao, B. Appa

    2014-04-24

    Lead bismuth alumina borate glasses codoped with Er{sup 3+}/Yb{sup 3+} were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω{sub 2}, Ω{sub 4} and Ω{sub 6} parameters. Radiative properties like branching ratio β{sub r} and the radiative life time τ{sub R} have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+} respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb{sup 3+} and Er{sup 3+}.

  8. Structural, dielectric and optical properties of lithium borate-bismuth tungstate glass-ceramics

    SciTech Connect

    Murugan, G.S.; Varma, K.B.R.

    1999-12-01

    Glasses in the system (1 {minus} x)Li{sub 2}B{sub 4}O{sub 7}-xBi{sub 2}WO{sub 6} (0.1 {le} x {le} 0.35) were prepared by spat quenching technique. Powder X-ray diffraction (XRD) and differential thermal analysis (DTA) were employed to characterize the as-quenched glasses. High-resolution transmission electron microscopy (HR-TEM) revealed the presence of fine, nearly spherical crystallites of Bi{sub 2}WO{sub 6} varying from 1.5 to 20 nm in size, depending on x in the as-quenched glasses. The glasses (corresponding to x = 0.3) heat-treated at 723 K for 6 h gave rise to a clear crystalline phase of Bi{sub 2}WO{sub 6} embedded in the Li{sub 2}B{sub 4}O{sub 7} glass matrix, as observed by X-ray studies. The dielectric constants of the as-quenched glasses as well as the glass-ceramics decreased with increase in frequency (40Hz--100 kHz) at 300 K, and the value obtained for the glass-ceramic (x = 0.2) is in agreement with the values predicted using Maxwell's model and the logarithmic mixture rule. The dielectric constants for both the as-quenched glass and the glass-ceramic increased with increase in temperature (300--873 K) and exhibited anomalies close to the onset of the crystallization temperature of the host glass matrix. The optical transmission properties of these glass-ceramics were found to be compositional dependant.

  9. Effect of mixed transition metal ions on DC conductivity in lithium bismuth borate glasses

    NASA Astrophysics Data System (ADS)

    Khasa, S.; Yadav, Arti; Dahiya, M. S.; Seema, Ashima, Agarwal, A.

    2015-06-01

    The DC conductivities of glasses having composition x(2NiO.V2O5).(30-x)Li2O.20Bi2O3.50B2O3 (with x=0, 2, 5, 7 and 10, i.e. NVLBB glasses) and glass samples having composition 7NiO.23 Li2O.20Bi2O3.50B2O3 and 7V2O5.23Li2O.20Bi2O3.50B2O3 (NLBB and VLBB respectively) are investigated as a function of temperature. Conductivity for glasses containing higher percentage of lithium ions is predominantly ionic and in glasses containing higher percentage of transition metal (TM) ions is predominantly electronic. The observed increase in conductivity with x and peak-like behavior at x=7 in NVLBB glasses due to competitive transport of small polaron contributing to a significant structural change in NVLBB glasses. Variation of molar volume and density was also observed with x. In NVLBB glasses, as x increases density increases except a slight decrease at x=7. Also density increases in NLBB whereas in case of VLBB it decreases in comparison to NVLBB1 glass composition. Mott's small polaron hopping (SPH) model has been applied to analyze the high temperature conductivity data and activation energy.

  10. Composition and concentration dependence of spectroscopic properties of Nd 3+-doped tellurite and metaborate glasses

    NASA Astrophysics Data System (ADS)

    Jyothi, L.; Venkatramu, V.; Babu, P.; Jayasankar, C. K.; Bettinelli, M.; Mariotto, G.; Speghini, A.

    2011-04-01

    The spectroscopic properties of tellurite glasses of composition (in mol%) TNKNd: (70 - x)TeO 2-15Nb 2O 5-15K 2O- xNd 2O 3 ( x = 0.1, 1.0, 1.5, 2.0 and 2.5) and TNLNd10: 69TeO 2-15Nb 2O 5-15Li 2O-1.0Nd 2O 3 and lithium metaborate glass of composition LBNNd10: 89LiBO 2-10Nb 2O 5-1.0Nd 2O 3 have been investigated using absorption and emission spectra and decay curve analysis. An energy level analysis has been carried out considering the experimental energy positions of the absorption and emission bands, using the free-ion Hamiltonian model. The spectral intensities have been calculated by using the Judd-Ofelt theory and in turn the radiative properties such as radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes have been estimated. The decay curves at the lower concentrations are exponential while they show a non-exponential behavior at higher concentrations (?1.0 mol%) due to energy transfer processes. The effective lifetimes for the 4F 3/2 level are found to decrease with increase in Nd 2O 3 concentration for all the glasses under investigation. The non-exponential decay curves have been well-fitted to the Yokota-Tanimoto model with S = 6, indicating that the nature of energy transfer is of dipole-dipole type and energy migration also plays an important role. The results obtained have been compared with Nd 3+-doped phosphate, fluorophosphate, lead borate, tellurite, germanate and silicate glasses and Nd 3+-doped YAG ceramic and Ca 2Nb 2O 7 crystals.

  11. Structural and luminescence behavior of Er(3+) ions doped Barium tellurofluoroborate glasses.

    PubMed

    Annapoorani, K; Maheshvaran, K; Arunkumar, S; Suriya Murthy, N; Marimuthu, K

    2015-01-25

    Er(3+) doped Barium tellurofluoroborate glasses (BTFBxE) with the chemical composition (30-x)TeO2+30B2O3+20BaO+20BaF+xEr2O3 (where x=0.01, 0.05, 0.1, 0.5, 1.0 and 2.0 in wt%) were prepared following the melt quenching technique. The different vibrational modes of borates and tellurites in the prepared glasses were explored through FTIR and Raman spectra. The optical absorption spectra have been used to determine the ionic/covalent nature of the metal-ligand bond in the prepared glasses with the help of Nephelauxetic ratio (β) and bonding parameter (δ) studies. The optical band gap of direct and indirect allowed transitions were determined from Tauc's plot and the variations of band gap energy with structural arrangements were discussed. The Urbach energy values were determined and the relatively lower values of the Urbach's energy reveal the minimal degree of disorderness in the prepared glasses. The oscillator strengths (fexp and fcal) and Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6) were calculated with the application of JO theory and the trends of the JO intensity parameters are found to be Ω2>Ω6>Ω4 for all the prepared glasses with a minimum variation in Ω2 intensity parameter values. A bright green emission was observed from the (2)H11/2+(4)S3/2→ (4)I15/2 transition and the radiative properties such as transition probability (A), stimulated emission cross-section (σP(E)), branching ratio (βr) and radiative lifetime (τ) were calculated using the JO parameters. The suitability of the prepared glasses for the fabrication of photonic devices were also discussed and reported in the present work. PMID:25173526

  12. Structural and luminescence behavior of Er3+ ions doped Barium tellurofluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Annapoorani, K.; Maheshvaran, K.; Arunkumar, S.; Suriya Murthy, N.; Marimuthu, K.

    2015-01-01

    Er3+ doped Barium tellurofluoroborate glasses (BTFBxE) with the chemical composition (30 - x)TeO2 + 30B2O3 + 20BaO + 20BaF + xEr2O3 (where x = 0.01, 0.05, 0.1, 0.5, 1.0 and 2.0 in wt%) were prepared following the melt quenching technique. The different vibrational modes of borates and tellurites in the prepared glasses were explored through FTIR and Raman spectra. The optical absorption spectra have been used to determine the ionic/covalent nature of the metal-ligand bond in the prepared glasses with the help of Nephelauxetic ratio (β) and bonding parameter (δ) studies. The optical band gap of direct and indirect allowed transitions were determined from Tauc's plot and the variations of band gap energy with structural arrangements were discussed. The Urbach energy values were determined and the relatively lower values of the Urbach's energy reveal the minimal degree of disorderness in the prepared glasses. The oscillator strengths (fexp and fcal) and Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6) were calculated with the application of JO theory and the trends of the JO intensity parameters are found to be Ω2 > Ω6 > Ω4 for all the prepared glasses with a minimum variation in Ω2 intensity parameter values. A bright green emission was observed from the 2H11/2 + 4S3/2 → 4I15/2 transition and the radiative properties such as transition probability (A), stimulated emission cross-section (σPE), branching ratio (βr) and radiative lifetime (τ) were calculated using the JO parameters. The suitability of the prepared glasses for the fabrication of photonic devices were also discussed and reported in the present work.

  13. Preparation of Ferroelectric KNbO3 Based Borate Glass System.

    PubMed

    Kruea-In, Chatchai; Intawin, Pratthana; Leenakul, Wilaiwan

    2015-11-01

    The incorporation method was employed to produce ferroelectric glass ceramics from the K2O-Nb2O5-B2O3 glass system. The nanocrystalline potassium niobate (KNbO3) was first prepared using a simple mixed oxide method, where the B2O3 was initially mixed and then melted to form glass. The successfully produced optically transparent glass was then subjected to a heat treatment schedule for further crystallization at temperatures ranging from 500 to 650 degrees C, which resulted in the precipitation of the KNbO3 phase, together with the K3B2Nb3O12 phase. Scanning electron microscopy (SEM) showed the presence of randomly oriented KNbO3 crystals dispersed in a continuous glass matrix. It was found that the glass ceramics subjected to the heat treatment at temperatures higher than 545 degrees C were opaque, while the lower gave a highly transparent glass ceramics. The crystal size and crystallinity were found to increase with increasing heat treatment temperature, which in turn plays an important role in controlling the properties of the glass ceramics, including physical, optical, and dielectric properties. PMID:26726678

  14. Silver doped nanobioactive glass particles for bone implant applications

    NASA Astrophysics Data System (ADS)

    Prabhu, M.; Kavitha, K.; Karunakaran, G.; Manivasakan, P.; Rajendran, V.

    2013-02-01

    Silica based silver doped nanobioactive glass compositions (58SiO2-33CaO-9P2O5 and 58SiO2-23CaO-9P2O5-10Ag2O(mol%)) were synthesized by a simple sol-gel route. The prepared samples were comprehensively characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopic studies. The results reveal that the prepared samples have amorphous phase with spherical morphology and having a particle size less than 100 nm. The specific surface areas were 90 and 61 m2g-1 respectively. The in vitro bioactivity of glass samples were confirmed by the formation of hydroxyapatite layer on glass surfaces. The Ag2O-doped nanobioactive glasse samples shows reveal significant antibacterial activity compare with base glasses.

  15. Electronic polarizability and interaction parameter of gadolinium tungsten borate glasses with high WO3 content

    NASA Astrophysics Data System (ADS)

    Taki, Yukina; Shinozaki, Kenji; Honma, Tsuyoshi; Dimitrov, Vesselin; Komatsu, Takayuki

    2014-12-01

    Glasses with the compositions of 25Gd2O3-xWO3-(75-x)B2O3 with x=25-65 were prepared by using a conventional melt quenching method, and their electronic polarizabilities, optical basicities Λ(no), and interaction parameters A(no) were estimated from density and refractive index measurements in order to clarify the feature of electronic polarizability and bonding states in the glasses with high WO3 contents. The optical basicity of the glasses increases monotonously with the substitution of WO3 for B2O3, and contrary the interaction parameter decreases monotonously with increasing WO3 content. A good linear correlation was observed between Λ(no) and A(no) and between the glass transition temperature and A(no). It was proposed that Gd2O3 oxide belongs to the category of basic oxide with a value of A(no)=0.044 Å-3 as similar to WO3. The relationship between the glass formation and electronic polarizability in the glasses was discussed, and it was proposed that the glasses with high WO3 and Gd2O3 contents would be a floppy network system consisting of mainly basic oxides.

  16. Impedance spectroscopic characterization of Sm2O3 containing lithium borate glasses.

    PubMed

    Ramteke, D D; Gedam, R S

    2014-12-10

    27.5 Li2O-(72.5-X) B2O3-X Sm2O3 (X=0.5, 1, 1.5 and 2) were prepared by conventional melt quench technique. Impedance spectroscopy (IS) is used to study the electrical properties of these prepared glasses. Modulus formalism is introduced to study relaxation behaviour of these glasses. Scaling model shows the good overlap of data on single master curve which suggests that conduction mechanism in these glasses is compositional dependent. Variation of dielectric constant and dielectric loss with the addition of Sm2O3 and frequency are discussed here. PMID:24929310

  17. Photostimulated luminescence from BaCl{sub 2}:Eu{sup 2+} nanocrystals in lithium borate glasses following neutron irradiation

    SciTech Connect

    Appleby, G. A.; Edgar, A.; Williams, G. V. M.; Bos, A. J. J.

    2006-09-04

    A glass-ceramic thermal neutron imaging plate material is reported. The material consists of a neutron sensitive 2B{sub 2}O{sub 3}-Li{sub 2}O glass matrix containing nanocrystallites of the storage phosphor BaCl{sub 2}:Eu{sup 2+}. When doped with 0.5 mol % Eu{sup 2+}, the neutron induced photostimulated luminescence (PSL) conversion efficiency of the {sup 10}B enriched glass-ceramic is around 60% of that a commercial neutron imaging plate, while the {gamma} sensitivity is an order of magnitude lower than that of the commercial plate. A Eu{sup 2+}-concentration series shows that the PSL efficiency for x rays is optimized at 0.01 mol % Eu{sup 2+}. Thermoluminescence measurements indicate trap depths in BaCl{sub 2}:Eu{sup 2+} ranging from 0.55 to 2.7 eV.

  18. Effect of alkali addition on DC conductivity and thermal properties of vanadium-bismo-borate glasses

    SciTech Connect

    Khasa, S. Dahiya, M. S.; Agarwal, A.

    2014-04-24

    The DC Conductivity and Differential Thermal Analysis of glasses with composition (30−x)Li{sub 2}O⋅xV{sub 2}O{sub 5}⋅20Bi{sub 2}O{sub 3}⋅50B{sub 2}O{sub 3}(x=15, 10, 5) has been carried out in order to study the effect of replacing the Transition Metal Oxide (TMO) with alkali oxide. A significant increase in the DC conductivity has been observed with increase in alkali content. Again the thermal measurements have shown the decrease in both glass transition temperature (T{sub g}) and crystallization temperature (T{sub x}). The Glass Stability (GS) and Glass Forming Ability (GFA) have also been calculated and these also were found to decrease with increase in alkali oxide content at the cost of TMO.

  19. Physical, structural and optical characterizations of borate modified bismuth-silicate-tellurite glasses

    NASA Astrophysics Data System (ADS)

    Berwal, Neelam; Kundu, R. S.; Nanda, Kirti; Punia, R.; Kishore, N.

    2015-10-01

    Quaternary bismuthate glasses with compositions xB2O3-(80 - x) Bi2O3-15SiO2-5TeO2 have been prepared by melt-quench technique. X-ray diffraction studies were performed to ascertain the amorphous nature of samples. The density, molar volume and crystalline volume decrease with increase in B2O3 content whereas the glass transition temperature shows the reverse trend. The Raman and FTIR spectra of the studied glasses indicate that B2O3 has been found to exist in the form of BO3 trigonal and BO4 tetrahedral structural units and vibrations corresponding to these structural units increase with increase in B2O3 content. SiO2 is present in the form of SiO4 tetrahedral structural units and TeO2 in the form of TeO3 structural units. Bismuth plays the role of network modifier [BiO6 octahedra] as well as network former [BiO3 pyramids] for all the glass compositions. The optical band gap energy has been calculated from the fitting of both Mott and Davis's model and Hydrogenic excitonic model with the experimentally observed absorption spectra. A good fitting of experimental data with HEM indicates the excitonic formation in the studies glass system. The values of optical band gap energy show nonlinear behavior due to the structural changes that take place in the present glass samples. The Urbach energy calculated using Urbach empirical formula for studied glass samples suggest the possibility of reduction in defect concentrations. The metallization criterion of the presently studied samples suggests that the prepared glasses may be potential candidates for nonlinear optical applications.

  20. Effects of host glasses on luminescence properties of Sm3+, Pr3+ co-doped glass

    NASA Astrophysics Data System (ADS)

    Shimizu, Y.; Watanabe, K.; Uemura, H.; Fuchi, S.; Takeda, Y.

    2015-06-01

    We calculated density/molecular weight ratio of glass former oxides and modifier oxides to increase a number density of rare-earth ions in glass phosphor. Based on the calculated results, GeO2 and ZnO were chosen for the glass former oxide and the modifier oxide, respectively. The effects of substituting GeO2 for B2O3, ZnO for Sb2O3, or ZnO for Bi2O3 on luminescence spectra in Sm3+-doped glass were not observed. On the other hand, a drastically luminescence spectrum changing of Pr3+-doped glass was observed by substituting GeO2 for B2O3. The output power of Sm3+ -doped glass and that of Pr3+ -doped glass increased with substituting ZnO for Bi2O3. We successfully achieved an ultra-wideband luminescence from 760 nm to 1100 nm with the output power of 2.5 mW by combining a blue LED with 0.15Sm2O3-0.12Pr6O11-10ZnO-45Sb2O3-45GeO2 glass in one package.

  1. Preparation of hollow hydroxyapatite microspheres by the conversion of borate glass at near room temperature

    SciTech Connect

    Yao, Aihua; Ai, Fanrong; Liu, Xin; Wang, Deping; Huang, Wenhai; Xu, Wei

    2010-01-15

    Hollow hydroxyapatite microspheres, consisting of a hollow core and a porous shell, were prepared by converting Li{sub 2}O-CaO-B{sub 2}O{sub 3} glass microspheres in dilute phosphate solution at 37 {sup o}C. The results confirmed that Li{sub 2}O-CaO-B{sub 2}O{sub 3} glass was transformed to hydroxyapatite without changing the external shape and dimension of the original glass object. Scanning electron microscopy images showed the shell wall of the microsphere was built from hydroxyapatite particles, and these particles spontaneously align with one another to form a porous sphere with an interior cavity. Increase in phosphate concentration resulted in an increase in the reaction rate, which in turn had an effect on shell wall structure of the hollow hydroxyapatite microsphere. For the Li{sub 2}O-CaO-B{sub 2}O{sub 3} glass microspheres reacted in low-concentration K{sub 2}HPO{sub 4} solution, lower reaction rate and a multilayered microstructure were observed. On the other hand, the glass microspheres reacted in higher phosphate solution converted more rapidly and produced a single hydroxyapatite layer. Furthermore, the mechanism of forming hydroxyapatite hollow microsphere was described.

  2. Investigations on spectral features of tungsten ions in sodium lead alumino borate glass system

    NASA Astrophysics Data System (ADS)

    Madhuri, V.; Kumar, J. Santhan; Rao, M. Subba; Cole, Sandhya

    2015-03-01

    Na2O-PbO-Al2O3-B2O3 (NPAB) glasses mixed with different concentrations of WO3 (ranging from 0 to 2.5 mol%) are synthesized by conventional melt quenching method. The samples are characterized by X-ray diffraction (XRD), optical absorption, Electron paramagnetic resonance (EPR) and Fourier transform infrared (FT-IR) spectroscopic techniques. Glass formation is confirmed by X-ray diffraction spectra. The optical absorption spectra of these glasses exhibited a predominant broad band peak at about 850-870 nm is identified due to dxy-dx2-y2 transition of W5+ ions. From the optical absorption spectral data, optical band gap (Eopt) and Urbach energy (ΔE) are evaluated. From EPR spectra the strength of the signal is increased and hyperfine splitting is resolved with increasing concentration of WO3 in the glass matrix. The FT-IR spectral studies have pointed out the existence of conventional BO3, BO4, B-O-B, PbO4, WO4 and WO6 structural units of these glasses. Various physical properties and optical basicity are also evaluated with respect to the concentration of WO3 ions.

  3. Novel borate glass/chitosan composite as a delivery vehicle for teicoplanin in the treatment of chronic osteomyelitis.

    PubMed

    Jia, Wei-Tao; Zhang, Xin; Luo, Shi-Hua; Liu, Xin; Huang, Wen-Hai; Rahaman, Mohamed N; Day, Delbert E; Zhang, Chang-Qing; Xie, Zong-Ping; Wang, Jian-Qiang

    2010-03-01

    Composite materials composed of borate bioactive glass and chitosan (designated BGC) were investigated in vitro and in vivo as a new delivery system for teicoplanin in the treatment of chronic osteomyelitis induced by methicillin-resistant Staphylococcus aureus (MRSA). In vitro, the release of teicoplanin from BGC pellets into phosphate-buffered saline (PBS), as well as its antibacterial activity, were determined. The compressive strength of the pellets was measured after specific immersion times, and the structure of the pellets was characterized using scanning electron microscopy and X-ray diffraction. In vivo, the tibial cavity of New Zealand White rabbits was injected with MRSA strain to induce chronic osteomyelitis, treated by debridement after 4weeks, implanted with teicoplanin-loaded BGC pellets (designated TBGC) or BGC pellets, or injected intravenously with teicoplanin. After 12weeks' implantation, the efficacy of the TBGC pellets for treating osteomyelitis was evaluated using hematological, radiological, microbiological and histological techniques. When immersed in PBS, the TBGC pellets provided a sustained release of teicoplanin, while the surface of the pellets was converted to hydroxyapatite (HA). In vivo, the best therapeutic effect was observed in animals implanted with TBGC pellets, resulting in significantly lower radiological and histological scores, a lower positive rate of MRSA culture, and an excellent bone defect repair, without local or systemic side effects. The results indicate that TBGC pellets are effective in treating chronic osteomyelitis by providing a sustained release of teicoplanin, in addition to participating in bone regeneration. PMID:19770078

  4. Bioactive borate glass promotes the repair of radius segmental bone defects by enhancing the osteogenic differentiation of BMSCs.

    PubMed

    Zhang, Jieyuan; Guan, Junjie; Zhang, Changqing; Wang, Hui; Huang, Wenhai; Guo, Shangchun; Niu, Xin; Xie, Zongping; Wang, Yang

    2015-12-01

    Bioactive borate glass (BG) has emerged as a promising alternative for bone regeneration due to its high osteoinductivity, osteoconductivity, compressive strength, and biocompatibility. However, the role of BG in large segmental bone repair is unclear and little is known about the underlying mechanism of BG's osteoinductivity. In this study, we demonstrated that BG possessed pro-osteogenic effects in an experimental model of critical-sized radius defects. Transplanting BG to radius defects resulted in better repair of bone defects as compared to widely used β-TCP. Histological and morphological analysis indicated that BG significantly enhanced new bone formation. Furthermore, the degradation rate of the BG was faster than that of β-TCP, which matched the higher bone regeneration rate. In addition, ions from BG enhanced cell viability, ALP activity, and osteogenic-related genes expression. Mechanistically, the critical genes Smad1/5 and Dlx5 in the BMP pathway and p-Smad1/5 proteins were significantly elevated after BG transplantation, and these effects could be blocked by the BMP/Smad specific inhibitor. Taken together, our findings suggest that BG could repair large segmental bone defects through activating the BMP/Smad pathway and osteogenic differentiation in BMSCs. PMID:26586668

  5. Synthesis of novel organic-ligand-doped sodium bis(oxalate)-borate complexes with tailored thermal stability and enhanced ion conductivity for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Ge, Chunhua; Wang, Lixia; Xue, Lili; Wu, Zhong-Shuai; Li, Hehe; Gong, Zailin; Zhang, Xiang-Dong

    2014-02-01

    A series of novel organic-ligand-doped sodium bis(oxalate)-borate complexes, including sodium bis[salicylato(2-)]-borate (NBSB), sodium[salicylato benzenediol]borate (NBDSB), sodium bis[oxalate]-borate (NBOB) and its derivatives NBOB(C2H2O4)0.2, NBOB(C7H4O3)0.2, NBOB(C7H4O3)0.6, NBOB(C6H6O2)0.15 and NBOB(C6H6O2)0.3 fabricated by solid-state reaction are firstly developed as new-type electrolytes for sodium ion batteries. These resulting sodium boron salts possess good solubility in an abroad range of organic solvents (such as PC, AN, DMF, PC + AN, PC + DMF), tailored thermal stability from 300 to 353 °C, improved ion conductivity (>1 × 10-3 S cm-1), environmental friendliness and low cost. Therefore, we believe that these new-type sodium boron salts show great potential as a new class of electrolyte for high-performance sodium ion batteries.

  6. Spectral investigations of Sm{sup 3+}-doped oxyfluorosilicate glasses

    SciTech Connect

    Ramachari, D.; Rama Moorthy, L.; Jayasankar, C.K.

    2013-09-01

    Graphical abstract: The figure shows the emission spectra of Sm{sup 3+} doped KNSZL glass for different concentrations. Among the four emission transitions {sup 4}G{sub 5/2} → {sup 6}H{sub 5/2}, {sup 4}G{sub 5/2} → {sup 6}H{sub 7/2}, {sup 4}G{sub 5/2} → {sup 6}H{sub 9/2} and {sup 4}G{sub 5/2} → {sup 6}H{sub 11/2}, the {sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition of KNSZLSm10 glass is more intense compared with all the transitions. The insert figure shows, the color coordinates (0.59, 0.41) of KNSZLSm10 glass is located on the perimeter of the chromaticity diagram at 592 nm which appears to be closest to the orange color. From these results the KNSZLSm10 glass could be useful for optical amplifiers, waveguides, telecommunications and orange LEDs. - Highlights: • From the DTA, the undoped KNSZL glass more precisely in fiberdrawing. • The XRD pattern confirmed the KNbO{sub 3} nanocrystallites of undoped KNSZL glass. • FTIR and Raman data of KNSZLSm10 glass revealed structural properties. • Judd–Ofelt analysis and decay measurements were carried out. • The optical gain parameter of the investigated glass is 18.13 × 10{sup −25} cm{sup 2} s. - Abstract: Sm{sub 2}O{sub 3}-doped oxyfluorosilicate glasses were prepared by melt-quenching method. The differential thermal analysis and X-ray diffraction were carried out to investigate the glass transition temperature and structure of precursor glass. Infrared spectroscopy, Raman, optical absorption, photoluminescence and decay measurements were carried out for Sm{sup 3+}-doped oxyfluorosilicate glasses. From the absorption spectrum, the Judd–Ofelt intensity parameters have been evaluated to predict the radiative properties for the emission levels of Sm{sup 3+} ions. The lifetimes of {sup 4}G{sub 5/2} level are found to decrease from 1.17 to 0.93 ms due to the energy transfer, when the concentration of Sm{sup 3+} ions increases from 0.1 to 2.0 mol%. The optical gain parameter (18.13 × 10{sup −25} cm{sup 2} s) of the investigated glass is found to be higher than the other Sm{sub 2}O{sub 3}-doped glass systems.

  7. Efficiency and tuning of the erbium-doped glass lasers

    NASA Astrophysics Data System (ADS)

    Fromzel, Victor A.; Kuchma, Igor G.; Lunter, Sergei G.; Mak, Artur A.; Petrov, Aleksey A.

    1992-11-01

    Erbium-doped glass lasers operated near by 1 5 mm wavelength are helpful for medicine and biology optical communication and eye-safe range finder systems. Advances in erbium-doped glass especially phosphate glass and lasers based on it have been extensive in recent years. Nowadays we can approve that erbium glass lasers are not worse compared with the neodymium ones by many spectroscopic and laser properties. Developments of the energy spectral and temporal characteristics and tuning near the 1500 nm wavelength of the erbium - doped phosphate glass lasers are reported. 2. SPECTROSCOPIC PECULIARITIES OF THE ERBIUM DOPED GLASS Phosphate erbium-doped glass possess a number of spectroscopic peculiarities as a laser active medium. Energy level diagrams of Er3 ions and two other its co-doped ions -Yb3 and Cr3 and the actual transitions (radiate and nonradiate) between them are shown in Fig. 1 (a). Absorption spectrum of that phosphate glass is also shown in Fig. 1 (b) . One can see that the whole pum energy is absorbed only by coactivators - Yb Cr - Yb E r and Cr3 - and then quickly and efficiently transferred from them to Er3 ions. Thus ''7 lasing and pumping of the erbium glass are ''4 realized by means of quite different ions. 4 Thanks to that one can get a low laser threshold t1/2 usin a small doping of Er3 ions (about 1019 I3/2 cm ) and the same time have a high efficient 4T pumoing by using the big concentration of ions 15/2 Yb3 and Cr3 in them (1021 cm3 and 1020 b cm3 accordingly). Obstacles for high efficiency of the lasers may be connected with either increase of the back pump energy transfer from Yb3 ions to Cr3 ones by too large concentration of Cr3 ions or thermal distortions of the active medium. Optimal pumping conditions for lamp pumped Er - doped glass laser differ from neodymium ones. It is explained by the important role of pump energy transfer processes in Er - doped glass. In order to have of high efficient pumping it is necessary that energy transfer rates from Yb3 to Er3 - 3+ 3+ WybEr and from Cr to Yb - WCrYb would be a lot of more then pumping rate W p (mainly object to WYbEr W1). It means the need to use pump pulse durations of about 1O - 102 s and more in that lasers. 3. EFFICIENCY AND THERMAL DISTORTIONS IN THE LASERS Efficiency of the lamp pumped Cr - Yb - Er doped phosphate glass oscillator can be up to 3 or some more (slope efficiency is up to 3. 5 ) /1 at free - running operation and storage efficiency of amplifiers based on the glass can be up to 1. 2 / 3 /. It was achieved

  8. Role of copper metal or oxide on physical properties of lithium borate glass

    NASA Astrophysics Data System (ADS)

    Kashif, I.; Ratep, A.

    2015-12-01

    The effect of the addition of copper metal or copper oxide on lithium tetraborate glass was studied using X-ray powder diffraction, Optical, density and FTIR. The effect of adding Cu metal has a large effect than the addition of CuO and contributes to increase the NBOs than CuO. And the addition of Cu metal increases the homogeneity of lithium tetraborate glass. The glass sample containing 2 mol % CuO has the higher value of optical band gap Egopt, lower the fraction of four-coordination boron atoms N4 and Urbach energy (Eu) than the other samples containing different copper metal or copper oxide concentration. And the decrease in Urbach energy indicating that decreasing localized states in forbidden gap due to decrease in NBOs. The glass sample containing 2 mol % CuO can be used as a narrow band color filter (band width = 250, band half width = 130 and band center = 486 nm).

  9. Luminescence properties of Sm3+-doped fluorosilicate glasses

    NASA Astrophysics Data System (ADS)

    Linganna, K.; Basavapoornima, Ch.; Jayasankar, C. K.

    2015-06-01

    Sm2O3-doped fluorosilicate glasses (SiO2+Nb2O5+K2O+ZnF2) were prepared by the melt quenching technique and are characterized through various spectroscopic techniques such as Raman, optical absorption, excitation, emission and decay to derive various spectroscopic properties. Raman analysis has been carried out in order to know the vibrational groups present in the glass matrix. The optical band gap and Urbach energies have been evaluated from the absorption edges of the absorption spectra of 1.0 mol% Sm2O3 doped fluorosilicate glass. The Judd-Ofelt (JO) analysis has been applied to evaluate the intensity parameters, ?? (?=2,4 and 6), for 1.0 mol% Sm2O3 doped fluorosilicate glass. These JO parameters have been used to evaluate radiative properties such as radiative transition probabilities, branching ratios, radiative lifetime and stimulated emission cross-sections for the luminescent levels of Sm3+ ion. The decay curve analysis has been performed for all the glasses in order to know the energy transfer processes between Sm3+ ions. The results indicate that the present glasses could be useful for photonics applications.

  10. Radioluminescence properties of Sm-doped fluorochlorozirconate glasses and glass-ceramics

    NASA Astrophysics Data System (ADS)

    Okada, Go; Edgar, Andy; Kasap, Safa; Yanagida, Takayuki

    2016-02-01

    We have investigated X-ray induced radioluminescence (XL) properties of Sm-doped fluorochlorozirconate (FCZ) glasses and glass-ceramics. The FCZ glass is a modified ZBLAN glass which shows a very high optical transmission over a wide spectral range. The glass matrix includes Sm3+-doped nanocrystals of BaCl2 after heat-treatment at temperatures above 250 °C. The glass-ceramic emits red light under UV and X-ray exposure. Since conventional Si-based photodetectors, e.g., CCDs, have the highest quantum efficiency to red light in general, the Sm-doped FCZ glass-ceramic plate can be a good candidate as a scintillator material for indirect radiation detection. Moreover, a very broad emission is present in the glass-ceramic around 300-500 nm, which is attributed to a self-trapped exciton (STE) emissions. The temperature dependence of X-ray induced luminescence and photoluminescence are very similar. The XL light yield is linearly proportional to the X-ray exposure rate for rates higher than 20 mR/s. For low exposure rates, emissions by Sm2+ are more sensitive than others, leading to a nonlinear response.

  11. XRD and FTIR structural investigation of gadolinium-zinc-borate glass ceramics

    SciTech Connect

    Borodi, G.; Pascuta, P.; Dan, V.; Pop, V.; Stefan, R.; Radulescu, D.

    2013-11-13

    X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy measurements have been employed to investigate the (Gd{sub 2}O{sub 3}){sub x}⋅(B{sub 2}O{sub 3}){sub (60−x)}⋅(ZnO){sub 40} glass ceramics system, with 0 ≤ x ≤ 15 mol%. After heat treatment applied at 860 °C for 2 h, some structural changes were observed and new crystalline phases appeared in the structure of the samples. In these glass ceramics four crystalline phases were identified using powder diffraction files (PDF 2), namely ZnB{sub 4}O{sub 7}, Zn{sub 4}O(B{sub 6}O{sub 12}), Zn{sub 3}(BO{sub 3}){sub 2} and GdBO{sub 3}. From the XRD data, the average unit-cell parameter and the quantitative ratio of the crystallographic phases in the studied samples were evaluated. FTIR data revealed that the BO{sub 3}, BO{sub 4} and ZnO{sub 4} are the main structural units of these glass ceramics network. The compositional dependence of the different structural units which appear in the studied samples was followed.

  12. EPR and impedance spectroscopic investigations on lithium bismuth borate glasses containing nickel and vanadium ions.

    PubMed

    Yadav, Arti; Khasa, Satish; Hooda, Ashima; Dahiya, Manjeet S; Agarwal, Ashish; Chand, Prem

    2016-03-15

    Glasses having composition 7NiO∙23Li2O∙20Bi2O3∙50B2O3, 7V2O5∙23Li2O∙20Bi2O3∙50B2O3 and x(2NiO∙V2O5)∙(30-x)Li2O∙50B2O3∙20Bi2O3 (with x=0, 2, 5, 7 & 10mol%) prepared through melt-quench route are explored by analyzing density, impedance spectroscopy and electron paramagnetic resonance (EPR). It is found that both density and molar volume increase with an increase in substitution of 2NiO∙V2O5 in the base glass matrix. Different dielectric parameters viz. dielectric loss (ε), electrical modulus (M), loss tangent (tanδ) etc. are evaluated and their variations with frequency and temperature are analyzed which reveals that these glasses exhibit a non-Debye relaxation behavior. A phenomenal description of the capacitive behavior is obtained by considering the circuitry as a parallel combination of bulk resistance (Rb) and constant phase element (CPE). The conduction mechanism is found to follow Quantum Mechanical Tunneling (QMT) model. Spin Hamiltonian Parameters (SHPs) and covalency rates are calculated from the EPR spectra of vanadyl ion. The observed EPR spectra confirmed that V(4+) ion exists as vanadyl ion in the octahedral coordination with tetragonal compression. PMID:26748341

  13. EPR and impedance spectroscopic investigations on lithium bismuth borate glasses containing nickel and vanadium ions

    NASA Astrophysics Data System (ADS)

    Yadav, Arti; Khasa, Satish; Hooda, Ashima; Dahiya, Manjeet S.; Agarwal, Ashish; Chand, Prem

    2016-03-01

    Glasses having composition 7NiO • 23Li2O • 20Bi2O3 • 50B2O3, 7V2O5 • 23Li2O • 20Bi2O3 • 50B2O3 and x(2NiO • V2O5) • (30 - x)Li2O • 50B2O3 • 20Bi2O3 (with x = 0, 2, 5, 7 & 10 mol%) prepared through melt-quench route are explored by analyzing density, impedance spectroscopy and electron paramagnetic resonance (EPR). It is found that both density and molar volume increase with an increase in substitution of 2NiO • V2O5 in the base glass matrix. Different dielectric parameters viz. dielectric loss (ε), electrical modulus (M), loss tangent (tanδ) etc. are evaluated and their variations with frequency and temperature are analyzed which reveals that these glasses exhibit a non-Debye relaxation behavior. A phenomenal description of the capacitive behavior is obtained by considering the circuitry as a parallel combination of bulk resistance (Rb) and constant phase element (CPE). The conduction mechanism is found to follow Quantum Mechanical Tunneling (QMT) model. Spin Hamiltonian Parameters (SHPs) and covalency rates are calculated from the EPR spectra of vanadyl ion. The observed EPR spectra confirmed that V4 + ion exists as vanadyl ion in the octahedral coordination with tetragonal compression.

  14. Structural and spectroscopic behavior of Er3+:Yb3+ co-doped lithium telluroborate glasses

    NASA Astrophysics Data System (ADS)

    Annapoorani, K.; Maheshvaran, K.; ArunKumar, S.; Suriya Murthy, N.; Soukka, Tero; Marimuthu, K.

    2015-01-01

    A new series of Er3+:Yb3+ co-doped Lithium telluroborate glasses were prepared following the melt quenching technique. The structural analyzes were made through XRD, Raman, FTIR spectra to explore the different vibrations of borate and tellurite network. The absorption spectra have been used to determine the nature of the metal-ligand and further Band gap and Urbach's analysis have also been carried out. The oscillator strength value of the 2H11/2→4I15/2 hypersensitive transition is found to be higher and increases as the concentration of the RE ion increases which emphasis the asymmetry nature of the glasses. The magnitude of the JO intensity parameters follow the trend as Ω2>Ω4>Ω6 uniformly for all the prepared glasses. A bright green emission corresponding to the 2H11/2+4S3/2→ 4I15/2 transition and luminescence from 4I13/2→4I15/2 in eye safe region have also been observed. The radiative parameters such as radiative transition probability, stimulated emission cross-section, branching ratios, radiative lifetime, gain bandwidth and gain linewidth for the 4S3/2 and 4I13/2 level of the title glasses have also been determined. The absorption and emission cross-section corresponding to the 4I13/2 level has been calculated using McCumber theory. Lifetime measurements were made under 980 nm excitation and the quantum efficiency were also calculated to evaluate the appropriateness of the host matrix for the fabrication of laser materials and broad band amplifiers.

  15. Magnetic nanoparticles formed in glasses co-doped with iron and larger radius elements

    SciTech Connect

    Edelman, I.; Ivanova, O.; Ivantsov, R.; Velikanov, D.; Zabluda, V.; Zubavichus, Y.; Veligzhanin, A.; Zaikovskiy, V.; Stepanov, S.; Artemenko, A.; Curely, J.; Kliava, J.

    2012-10-15

    A new type of nanoparticle-containing glasses based on borate glasses co-doped with low contents of iron and larger radius elements, Dy, Tb, Gd, Ho, Er, Y, and Bi, is studied. Heat treatment of these glasses results in formation of magnetic nanoparticles, radically changing their physical properties. Transmission electron microscopy and synchrotron radiation-based techniques: x-ray diffraction, extended x-ray absorption fine structure, x-ray absorption near-edge structure, and small-angle x-ray scattering, show a broad distribution of nanoparticle sizes with characteristics depending on the treatment regime; a crystalline structure of these nanoparticles is detected in heat treated samples. Magnetic circular dichroism (MCD) studies of samples subjected to heat treatment as well as of maghemite, magnetite, and iron garnet allow to unambiguously assign the nanoparticle structure to maghemite, independently of co-dopant nature and of heat treatment regime used. Different features observed in the MCD spectra are related to different electron transitions in Fe{sup 3+} ions gathered in the nanoparticles. The static magnetization in heat treated samples has non-linear dependence on the magnetizing field with hysteresis. Zero-field cooled magnetization curves show that at higher temperatures the nanoparticles occur in superparamagnetic state with blocking temperatures above 100 K. Below ca. 20 K, a considerable contribution to both zero field-cooled and field-cooled magnetizations occurs from diluted paramagnetic ions. Variable-temperature electron magnetic resonance (EMR) studies unambiguously show that in as-prepared glasses paramagnetic ions are in diluted state and confirm the formation of magnetic nanoparticles already at earlier stages of heat treatment. Computer simulations of the EMR spectra corroborate the broad distribution of nanoparticle sizes found by 'direct' techniques as well as superparamagnetic nanoparticle behaviour demonstrated in the magnetization studies.

  16. Phosphor in glass with Eu3+ and Pr3+-doped silicate glasses for LED color conversion

    NASA Astrophysics Data System (ADS)

    Park, Hyun-A.; Lee, Yl Kwon; Im, Won Bin; Heo, Jong; Chung, Woon Jin

    2015-03-01

    Phosphor-in-glasses (PiGs) with rare earth (RE) doped SiO2-B2O3-RO glasses were prepared by embedding YAG:Ce3+ as the yellow phosphor. Eu3+ and Pr3+ were used to dope the glass, varying their concentrations in order to provide red emissions for possible chromaticity-control of white-light emitting diodes (WLEDs). The glass-to-phosphor mixing ratio was also varied to find the proper combination for color-controlled white LEDs. PiGs with RE-doped glasses were sintered at 750 C and polished to 250 ?m in thickness for blue LED color conversion. The photoluminescence spectra of the PiGs were monitored after they were mounted on commercial blue LED chips. Variation of color coordination, color rendering index and correlated color temperature were observed due to red emissions from the doped RE-ions. The spectral contribution of Eu3+ and Pr3+ ions to white LEDs under 450 nm LED excitation was discussed. The spatial distribution of phosphors within the glass matrix, and their possible interaction, was inspected by SEM. The thermal quenching effect was also investigated.

  17. Density, Electrical and Optical Properties of Yttrium-Containing Tellurium Bismuth Borate Glasses

    NASA Astrophysics Data System (ADS)

    Shaaban, M. H.; Ali, A. A.

    2014-11-01

    60B2O3-30Bi2O3-(10 - x) TeO2- xY2O3 mol.% ( x = 0, 0.1, 1, 2 and 5) glasses have been prepared by the conventional glass-melting technique. The influence of Y2O3 on the density, optical and electrical properties of the glass was investigated. The density decreased whereas the molar volume increased with increasing Y2O3. Optical transmission in the ultraviolet (UV) spectral region indicated that the values of direct and indirect optical band gap energies increased, which was attributed to structural changes induced by the addition of Y2O3. Urbach energy values decreased with increasing the Y2O3, which was attributed to a decrease in the broadening due to static disorder-related parts. Fourier transform infrared (FTIR) spectra revealed that the addition of Y2O3 transforms BO4 to BO3 and BiO3 to BiO6 groups. The decrease in the dc and ac electrical conductivities was attributed to the formation of [BiO6] units which leads to a decrease in acceptor levels of Bi5+ sites. The electric modulus formalism indicated that the conductivity relaxation at different frequencies was a temperature-independent dynamic process. The full width at half-maximum (FWHM) of the normalized modulus decreases with increasing Y2O3 content, suggesting that the decrease of the Y ion-ion distance increases the interaction between the Y ions.

  18. Electron Spin Resonance and optical absorption spectroscopic studies of manganese centers in aluminium lead borate glasses.

    PubMed

    SivaRamaiah, G; LakshmanaRao, J

    2012-12-01

    Electron Spin Resonance (ESR) and optical absorption studies of 5Al(2)O(3)+75H(3)BO(3)+(20-x)PbO+xMnSO(4) (where x=0.5, 1,1.5 and 2 mol% of MnSO(4)) glasses at room temperature have been studied. The ESR spectrum of all the glasses exhibits resonance signals with effective isotropic g values at ?2.0, 3.3 and 4.3. The ESR resonance signal at isotropic g?2.0 has been attributed to Mn(2+) centers in an octahedral symmetry. The ESR resonance signals at isotropic g?3.3 and 4.3 have been attributed to the rhombic symmetry of the Mn(2+) ions. The zero-field splitting parameter (zfs) has been calculated from the intensities of the allowed hyperfine lines. The optical absorption spectrum exhibits an intense band in the visible region and it has been attributed to (5)E(g)?(5)T(2g) transition of Mn(3+)centers in an octahedral environment. The optical band gap and the Urbach energies have been calculated from the ultraviolet absorption edges. PMID:23000927

  19. Characterization of borate glasses by W-band pulse electron-nuclear double resonance spectroscopy

    SciTech Connect

    Kordas, George; Goldfarb, Daniella

    2008-10-21

    (100-x) mol % B{sub 2}O{sub 3} x mol %Me{sub 2}O (Me=Li,Na,K) glasses, exposed to {gamma}-{sup 60}Co irradiation to produce paramagnetic states, were characterized by W-band (95 GHz) pulse electron-nuclear double resonance (ENDOR) spectroscopy in order to characterize local structures occurring in the range of compositions between x=16 and x=25 at which the 'boron oxide' anomaly occurs. The high resolution of nuclear frequencies allowed resolving the {sup 7}Li and {sup 11}B ENDOR lines. In the samples with x=16 and x=20 glasses, {sup 11}B hyperfine couplings of 16, 24, and 36 MHz were observed and attributed to the tetraborate, triborate, and boron oxygen hole center (BOHC) structures, respectively. The x=25 samples showed hyperfine couplings of 15 MHz for the tetraborate and 36 MHz for BOHC. Density functional theory (DFT) calculations predicted for these structures negative hyperfine couplings, which were confirmed by W-band ENDOR. This suggests that a spin polarization mechanism accounts for the negative hyperfine structure splitting.

  20. Characterization of borate glasses by W-band pulse electron-nuclear double resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Kordas, George; Goldfarb, Daniella

    2008-10-01

    (100-x)mol% B2O3 x mol % Me2O (Me=Li,Na,K) glasses, exposed to ?-Co60 irradiation to produce paramagnetic states, were characterized by W-band (95GHz ) pulse electron-nuclear double resonance (ENDOR) spectroscopy in order to characterize local structures occurring in the range of compositions between x =16 and x =25 at which the "boron oxide" anomaly occurs. The high resolution of nuclear frequencies allowed resolving the Li7 and B11 ENDOR lines. In the samples with x =16 and x =20 glasses, B11 hyperfine couplings of 16, 24, and 36MHz were observed and attributed to the tetraborate, triborate, and boron oxygen hole center (BOHC) structures, respectively. The x =25 samples showed hyperfine couplings of 15MHz for the tetraborate and 36MHz for BOHC. Density functional theory (DFT) calculations predicted for these structures negative hyperfine couplings, which were confirmed by W-band ENDOR. This suggests that a spin polarization mechanism accounts for the negative hyperfine structure splitting.

  1. Characterization of borate glasses by W-band pulse electron-nuclear double resonance spectroscopy.

    PubMed

    Kordas, George; Goldfarb, Daniella

    2008-10-21

    (100-x) mol % B(2)O(3) x mol % Me(2)O (Me = Li,Na,K) glasses, exposed to gamma-(60)Co irradiation to produce paramagnetic states, were characterized by W-band (95 GHz) pulse electron-nuclear double resonance (ENDOR) spectroscopy in order to characterize local structures occurring in the range of compositions between x=16 and x=25 at which the "boron oxide" anomaly occurs. The high resolution of nuclear frequencies allowed resolving the (7)Li and (11)B ENDOR lines. In the samples with x=16 and x=20 glasses, (11)B hyperfine couplings of 16, 24, and 36 MHz were observed and attributed to the tetraborate, triborate, and boron oxygen hole center (BOHC) structures, respectively. The x=25 samples showed hyperfine couplings of 15 MHz for the tetraborate and 36 MHz for BOHC. Density functional theory (DFT) calculations predicted for these structures negative hyperfine couplings, which were confirmed by W-band ENDOR. This suggests that a spin polarization mechanism accounts for the negative hyperfine structure splitting. PMID:19045204

  2. Origin of broad NIR photoluminescence in bismuthate glass and Bi-doped glasses at room temperature.

    PubMed

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar

    2009-07-15

    Bi-doped glasses with broadband photoluminescence in the near-infrared (NIR) spectral range are presently receiving significant consideration for potential applications in telecommunications, widely tunable fiber lasers and spectral converters. However, the origin of NIR emission remains disputed. Here, we report on NIR absorption and emission properties of bismuthate glass and their dependence on the melting temperature. Results clarify that NIR emission occurs from the same centers as it does in Bi-doped glasses. The dependence of absorption and NIR emission of bismuthate glasses on the melting temperature is interpreted as thermal dissociation of Bi(2)O(3) into elementary Bi. Darkening of bismuthate glass melted at 1300?C is due to the agglomeration of Bi atoms. The presence of Bi nanoparticles is confirmed by transmission electron microscopy, high-resolution energy dispersive x-ray spectroscopy and element distribution mapping. By adding antimony oxide as an oxidation agent to the glass, NIR emission centers can be eliminated and Bi(3+) is formed. By comparing with atomic spectral data, absorption bands at ?320, ?500, 700, 800and 1000nm observed in Bi-doped glasses are assigned to Bi(0) transitions [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], respectively, and broadband NIR emission is assigned to the transition [Formula: see text]. PMID:21828512

  3. Photosensitivity of Ge-doped phosphate glass to 244 nm irradiation

    SciTech Connect

    Suzuki, S.; Schuelzgen, A.; Sabet, S.; Moloney, J. V.; Peyghambarian, N.

    2006-10-23

    UV photosensitivity of Ge-doped phosphate glasses is examined by writing photoinduced gratings in bulk glass samples. Radiation-induced index changes up to {approx}3.5x10{sup -5} were obtained by diffraction efficiency measurements of UV written gratings. In contrast to phosphate glasses without intentional doping, no significant photodarkening at visible wavelength was observed in Ge-doped phosphate glasses after UV exposure. The measured index changes demonstrate the potential of Ge-doped phosphate glasses for the fabrication of a fiber Bragg grating, a key component for phosphate-glass-based photonic devices.

  4. Quantum Dot-Doped Glasses and Fibers: Fabrication and Optical Properties

    NASA Astrophysics Data System (ADS)

    Dong, Guoping; Wang, Haipeng; Chen, Guanzhong; Pan, Qiwen; Qiu, Jianrong

    2015-02-01

    Quantum dot-doped glasses have been the hotspot for their excellent electronic and optical properties. Owing to its tunable and broadband near-infrared (NIR) emission by controlling the size and distribution of QDs, QD-doped glasses and fibers are potentially applied in photoelectric devices. In this review, we mainly introduce the preparation, tunable emission, and multi-wavelength optical amplification of QD-doped glasses. Due to their excellent optical performances, the fabrication of QD-doped glass fibers is also presented, containing the successful fabrication of QD-doped glass fibers with tunable NIR emission. Furthermore, the achievements and existing problems about QD-doped glasses and fibers are also proposed with several prospects. These QD-doped glasses and fibers show promising applications as the gain medium of NIR broadband fiber amplifiers and tunable fiber lasers.

  5. Study of lithium borate glasses containing Bi{sub 2}O{sub 3}

    SciTech Connect

    Deshpande, A. V.; Raut, V. D.

    2014-04-24

    The effect of Bi{sub 2}O{sub 3} addition on the properties of 30Li{sub 2}O:(70−x)B{sub 2}O{sub 3}:xBi{sub 2}O{sub 3} (0≤x≤35 mol %) has been studied. Density and molar volume are increasing with Bi{sub 2}O{sub 3} content. The observed decrease in glass transition temperature and optical band gap has been explained on the basis of increase in non bridging oxygen which is supported by infrared spectroscopy. From the optical transmittance spectra it is observed that the cut off wavelength increases with Bi{sub 2}O{sub 3} content which is related to the structural changes.

  6. AC Conductivity Studies in Lithium-Borate Glass Containing Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Shivaprakash, Y.; Anavekar, R. V.

    2011-07-01

    Gold nanoparticles have been synthesized in a base glass with composition 30Li2O-70B2O3 using gold chloride (HAuCl4.3H2O) as a dopant. The samples are characterized using XRD, ESR, SEM and optical absorption in the visible range. AC conductivity studies have been performed at RT over a frequency range 100 to 10 MHz. The dc conductivity is calculated from the complex impedence plot. The dc conductivity is found to be increasing with the increase of dopant concentration. AC conductivity data is fitted with Almond-West law with power exponent `s'. The values of `s' is found to lie in the range of 0.70-0.73.

  7. Glass-crystal transition in silver-iodide-doped silver selenomolybdate glasses

    NASA Astrophysics Data System (ADS)

    Deb, B.; Ghosh, A.

    2013-12-01

    In this paper, we have studied the isothermal and non-isothermal glass-crystal transition in AgI-doped silver selenomolybdate glasses using differential scanning calorimetry. We have observed a strong dependence of AgI on the glass-crystal transition of these glasses. The activation energy for the crystallization and the dimensionality of the crystal growth for the isothermal and non-isothermal crystallization processes have been determined. The dimensionality of the crystal growth depends strongly on the AgI content and intriguingly shows different behavior when compared for isothermal and non-isothermal cases. For the present glass system the John-Mehl-Avrami model describes well the isothermal crystallization kinetics, while the Sestak-Berggren model is more suitable to describe the non-isothermal crystallization kinetics for glass-crystal transformation.

  8. Nanocrystallization in Yb3+-doped oxyfluoride glasses for laser cooling

    NASA Astrophysics Data System (ADS)

    Kummara, Venkata Krishaniah; Ledemi, Yannick; Soares de Lima Filho, Elton; Messaddeq, Younes; Kashyap, Raman

    2015-03-01

    Glass-ceramics are composite materials consisting of crystals which are controllably grown within a glass matrix usually by applying an appropriate heat treatment. They possess outstanding optical properties with applications in solid state lasers, optical amplifiers, and now, laser induced cooling. For laser cooling, the material should exhibit specific properties like low phonon energy environment around the lanthanide ions, low background losses, high transparency and high photoluminescence quantum yield. In the present study, oxyfluoride glasses and ultra-transparent nano glassceramics doped with different concentrations (2, 5, 8, 12, 16 and 20 mol %) of Yb 3+ ions have been prepared by conventional melt-quenching and subsequent thermal treatments at different temperatures, respectively. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements have been performed to characterize the thermal properties of the glass and the structural changes in the glass-ceramics, respectively. The XRD patterns confirm the growth of β-PbF2 nanocrystals as well as progressive incorporation of Yb 3+ ions. This enhances the Yb 3+ ion emission intensity which depends on the doping concentration and ceramization temperatures. The size (20 nm) of the nanocrystallites was estimated from the Sherrer's formula and found to increase with increasing ceramization temperature, small enough to avoid scattering losses and ensure an excellent transparency of the glass-ceramics comparable with that of the parent glass. An enhancement of the luminescence properties of Yb 3+ ions surrounded by a crystalline low phonon environment is observed. Finally, the utilization of these heavily Yb 3+-doped ultra-transparent materials for laser cooling and solid state laser applications is discussed.

  9. Evaluation of the proliferation and differentiation behaviors of mesenchymal stem cells with partially converted borate glass containing different amounts of strontium in vitro.

    PubMed

    Zhu, Yi; Ouyang, Yuanming; Chang, Yi; Luo, Congfeng; Xu, Jun; Zhang, Changqing; Huang, Wenhai

    2013-04-01

    The objective of this study was to examine the proliferation and differentiation behaviors of different compositions of strontium-containing (from 0-12 mol%) borate glasses with mesenchymal stem cells (MSCs). The Cell Counting Kit-8 (CCK-8) assay revealed that after three days of culturing, the 6Sr group had the highest cell growth rate. Analysis of cell morphology revealed that cells proliferated well near the particles of the samples in all the groups on day 3. On day 7, cells in the 6Sr group demonstrated a higher proliferation rate than other 4 groups under the microscope. When performing the Live-Dead staining experiment, the 6Sr group had the least number of dead cells. Total DNA qualification indicated that the 6Sr group had a statistically higher concentration compared with the remaining groups. It was found that on day 7, compared with the 0Sr group, the core binding factor ?1 (Cbfa1) mRNA expression level was significantly higher in the 6Sr, 9Sr and 12Sr groups. On day 14, compared with the 0Sr group, the bone sialoprotein (BSP) mRNA level was significantly higher in the 6Sr group. Additionally, on day 21, the 6Sr and 9Sr groups demonstrated higher osteocalcin (OCN) mRNA expression levels compared with the 0Sr group. In the alkaline phosphatase (ALP) activity test, on day 21, the 6Sr group presented a higher activity than the 0Sr group. Further, the number of mineralized nodules per unit in MSCs was measured by Alizarin Red S staining. The results showed that the 6Sr and 9Sr groups had the greatest number of mineralized nodules. Therefore, it could be concluded that borate glasses containing strontium oxide of 0, 3, 6, 9 and 12 mol% demonstrate a significant level of proliferation when interacting with MSCs. The borate glass containing 6 mol% strontium oxide had the greatest level of proliferation when cultured with MSCs. The borate glass containing 6 and 9 mol% strontium oxide facilitated an improved bone formation ability compared with the remaining two compositions. PMID:23446964

  10. Helium diffusion in curium-doped borosilicate waste glass

    NASA Astrophysics Data System (ADS)

    Fares, T.; Peuget, S.; Bouty, O.; Deschanels, X.; Magnin, M.; Jégou, C.

    2011-09-01

    The isothermal release of helium from 244Cm-doped borosilicate glass has been studied as a function of time at different annealing temperatures. Helium measurements were performed using a micro gas chromatograph coupled to a furnace installed in a hot cell at ATALANTE nuclear research facility. Plane-parallel glass samples were prepared from glass discs that had been stored for 5.1 years at room temperature, accumulating around 10 19 alpha decays per gram of glass, a level that will be reached in current nuclear glass packages several thousand years after disposal. The experimental helium release data were simulated using a 3D numerical model to determine the helium diffusion coefficients. The extracted diffusion coefficients follow the Arrhenius law with an activation energy of 0.61 ± 0.03 eV and a pre-exponential factor of (5.7 ± 1.6) × 10 -3 cm 2 s -1. The results were compared with literature data on damaged and undamaged glasses to assess the effect of glass damage on helium release. The helium release results are consistent with a thermal diffusion mechanism involving only one population of helium atoms. The helium diffusion coefficients were unaffected by the glass alpha damage.

  11. Ytterbium-doped glass-ceramics for optical refrigeration.

    PubMed

    Filho, Elton Soares de Lima; Krishnaiah, Kummara Venkata; Ledemi, Yannick; Yu, Ye-Jin; Messaddeq, Younes; Nemova, Galina; Kashyap, Raman

    2015-02-23

    We report for the first time the characterization of glass-ceramics for optical refrigeration. Ytterbium-doped nanocrystallites were grown in an oxyfluoride glass matrix of composition 2YbF(3):30SiO(2)-15Al(2)O(3)-25CdF(2)-22PbF(2)-4YF(3), forming bulk glass-ceramics at three different crystalisation levels. The samples are compared with a corresponding uncrystalised (glass) sample, as well as a Yb:YAG sample which has presented optical cooling. The measured X-ray diffraction spectra, and thermal capacities of the samples are reported. We also report for the first time the use of Yb:YAG as a reference for absolute photometric quantum efficiency measurement, and use the same setup to characterize the glass and glass-ceramic samples. The cooling figure-of-merit was measured by optical calorimetry using a fiber Bragg grating and found to depend on the level of crystallization of the sample, and that samples with nanocrystallites result in higher quantum efficiency and lower background absorption than the pure-glass sample. In addition to laser-induced cooling, the glass-ceramics have the potential to serve as a reference for quantum efficiency measurements. PMID:25836500

  12. Pr3+-doped phosphate glasses for fiber amplifiers operating at 1.38-1.53 ?m of the fifth optical telecommunication window

    NASA Astrophysics Data System (ADS)

    Han, Xiaozhe; Shen, Lifan; Pun, Edwin Yue Bun; Ma, Tiecheng; Lin, Hai

    2014-05-01

    Effective near-infrared emission covering the fifth optical telecommunication window (1380-1525 nm) has been observed in Pr3+-doped phosphate (LCBALP) glasses. Judd-Ofelt parameters ?2 (9.17 10-20 cm2), ?4 (16.50 10-20 cm2) and ?6 (2.41 10-20 cm2) indicate a high inversion asymmetrical and strong covalent environment in the optical glasses. The effective bandwidth (??eff) of the corresponding 1D2 ? 1G4 transition emission is obtained to be 148 nm, and the maximum stimulated emission cross-section (?em) at 1467.5 nm is derived to be 1.29 10-20 cm2. The quantum efficiency of Pr3+:1D2 level is identified to be 85.36%. The broad effective bandwidth and the large emission cross-section profile indicate that Pr3+-doped LCBALP glass fiber is promising in the realization of effective broadband amplification, especially at E- and S-band. As an expectation, the mature oxide glasses with Pr3+-doping, such as borate, phosphate and silicate glasses, are expected to be attractive candidates for broadband signal amplifiers operating at the fifth optical telecommunication window.

  13. Temperature dependent electrical transport characteristics of BaTiO3 modified lithium borate glasses

    NASA Astrophysics Data System (ADS)

    Thakur, Vanita; Singh, Anupinder; Awasthi, A. M.; Singh, Lakhwant

    2015-08-01

    The glass samples with composition (70B2O3-29Li2O-1Dy2O3)-xBT; x = 0, 10 and 20 weight percent, have been prepared by conventional melt quench technique. The dielectric measurements as a function of temperature have been carried out on these samples in the frequency range 1 Hz-10 MHz. The dielectric relaxation characteristics of these samples have been studied by analyzing dielectric spectroscopy, dielectric loss, electric modulus formulation and electrical conductivity spectroscopy. It is found that the dielectric permittivity of the samples increases with an increase in the temperature and BT content. The frequency dependent ac conductivity has been analyzed using Jonscher's universal power law whereas non exponential KWW function has been invoked to fit the experimental data of the imaginary part of the electric modulus. The values of the activation energy determined from the electric modulus and that from dc conductivity have been found to be quite close to each other suggesting that the same type of charge barriers are involved in the relaxation and the conduction mechanisms. The stretched exponent (β) and the power exponent (n) have been found to be temperature and composition dependent. The decrease in n with an increase in temperature further suggested that the ac conduction mechanism of the studied samples follows the correlated barrier hopping (CBH) model.

  14. Bismuth-doped Mg - Al silicate glasses and fibres

    SciTech Connect

    Bufetov, Igor' A; Vel'miskin, V V; Galagan, B I; Denker, B I; Sverchkov, S E; Semjonov, S L; Firstov, Sergei V; Shulman, I L; Dianov, Evgenii M

    2012-09-30

    This paper compares the optical properties of bulk bismuth-doped Mg - Al silicate glasses prepared in an iridium crucible to those of optical fibres prepared by the powder-in-tube method and having a core identical in composition to the glasses. The bulk glasses and fibres are shown to be similar in luminescence properties. The optical loss in the fibres in their IR luminescence band is about one order of magnitude lower than that in the crucible-melted glasses. The level of losses in the fibres and their luminescence properties suggest that such fibres can be made to lase near 1.15 {mu}m. (optical fibres, lasers and amplifiers. properties and applications)

  15. Magnetic resonance studies on radiation-induced point defects in mixed oxide glasses. I. Spin centers in B{sub 2}O{sub 3} and alkali borate glasses.

    SciTech Connect

    Shkrob, I. A.; Tadjikov, B. M.; Trifunac, A. D.; Chemistry

    2000-02-01

    Radiation-induced spin centers in vitreous boron trioxide and alkali borate glasses were studied using pulsed electron paramagnetic resonance (EPR). It is shown that electrons and holes in these glasses are trapped on valence alternation defects, undercoordinated oxygen (holes) and overcoordinated oxygen (electrons). The local environment around these defects has major effect on spin parameters of the corresponding spin centers. The electronic and atomic structure of spin-1/2 centers and their diamagnetic precursors is analyzed using semiempirical and ab initio calculations.

  16. Silver doped nanobioactive glass particles for bone implant applications

    SciTech Connect

    Prabhu, M.; Kavitha, K.; Karunakaran, G.; Manivasakan, P.; Rajendran, V.

    2013-02-05

    Silica based silver doped nanobioactive glass compositions (58SiO{sub 2}-33CaO-9P{sub 2}O{sub 5} and 58SiO{sub 2}-23CaO-9P{sub 2}O{sub 5}-10Ag{sub 2}O(mol%)) were synthesized by a simple sol-gel route. The prepared samples were comprehensively characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopic studies. The results reveal that the prepared samples have amorphous phase with spherical morphology and having a particle size less than 100 nm. The specific surface areas were 90 and 61 m{sup 2}g{sup -1} respectively. The in vitro bioactivity of glass samples were confirmed by the formation of hydroxyapatite layer on glass surfaces. The Ag{sub 2}O-doped nanobioactive glasse samples shows reveal significant antibacterial activity compare with base glasses.

  17. Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. II. In vitro and in vivo biological evaluation.

    PubMed

    Fu, Qiang; Rahaman, Mohamed N; Bal, B Sonny; Bonewald, Lynda F; Kuroki, Keiichi; Brown, Roger F

    2010-10-01

    In Part I, the in vitro degradation of bioactivAR52115e glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the borate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and degradation rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substrates for the repair and regeneration of contained bone defects. PMID:20540099

  18. Conversion of melt-derived microfibrous borate (13-93B3) and silicate (45S5) bioactive glass in a simulated body fluid.

    PubMed

    Liu, Xin; Rahaman, Mohamed N; Day, Delbert E

    2013-03-01

    Microfibrous bioactive glasses are showing a considerable capacity to heal soft tissue wounds, but little information is available on the mechanism of healing. In the present study, the conversion of microfibrous borate bioactive glass (diameter=0.2-5?m) with the composition designated 13-93B3 (5.5 Na2O, 11.1 K2O, 4.6 MgO, 18.5 CaO, 3.7 P2O5, 56.6 B2O3 wt%) was evaluated in vitro as a function of immersion time in a simulated body fluid (SBF) at 37C using structural and chemical techniques. Silicate 45S5glass microfibers (45 SiO2, 24.5 Na2O, 24.5 CaO, 6 P2O5 wt%) were also studied for comparison. Microfibrous 13-93B3 glass degraded almost completely and converted to a calcium phosphate material within 7-14days in SBF, whereas>85% of the silica remained in the 45S5 microfibers, forming a silica gel phase. An amorphous calcium phosphate (ACP) product that formed on the 13-93B3 microfibers crystallized at a slower rate to hydroxyapatite (HA) when compared to the ACP that formed on the 45S5 fibers. For immersion times>3days, the 13-93B3 fibers released a higher concentration of Ca into the SBF than the 45S5 fibers. The fast and more complete degradation, slow crystallization of the ACP product, and higher concentration of dissolved Ca in SBF could contribute to the capacity of the microfibrous borate 13-93B3 glass to heal soft tissue wounds. PMID:23233025

  19. Spectral investigations on Dy{sup 3+}-doped transparent oxyfluoride glasses and nanocrystalline glass ceramics

    SciTech Connect

    Babu, P.; Jang, Kyoung Hyuk; Kim, Eun Sik; Shi, Liang; Seo, Hyo Jin; Rivera-Lopez, F.; Rodriguez-Mendoza, U. R.; Lavin, V.; Vijaya, R.; Jayasankar, C. K.; Rama Moorthy, L.

    2009-01-01

    Dysprosium-doped oxyfluoride glasses and nanocrystalline glass ceramics have been synthesized and studied by x-ray diffraction, absorption, and visible and near-infrared emission spectra. The samples emit intense white light when populating the {sup 4}F{sub 9/2} level with a 451 nm laser light and, from the visible emission spectra, yellow to blue intensity ratios and chromaticity color coordinates have been calculated and their relative variation have been discussed based on the concentration of Dy{sup 3+} ions and the heat treatment conditions used to prepare the glass ceramics. Infrared emission has also been observed in glasses and glass ceramics after laser excitation at 800 nm, showing bands at 1.33 and 1.67 {mu}m, useful for optical amplification in fiber amplifiers.

  20. Mid-IR and far-IR investigation of AgI-doped silver diborate glasses

    SciTech Connect

    Hudgens, J.J.; Martin, S.W.

    1996-03-01

    The structures of {ital x}AgI+(1{minus}{ital x})Ag{sub 2}O{center_dot}2B{sub 2}O{sub 3} glasses, where 0.2{le}{ital x}{le}0.6, have been investigated using mid- and far-infrared spectroscopy. The mid-IR spectra revealed that in those glasses prepared using AgNO{sub 3} as the starting material for Ag{sub 2}O, the BO{sub 4}{sup {minus}}/BO{sub 3} ratio is constant with increasing amounts of AgI as would be expected form the proposed behavior of AgI in these glasses. However, a survey of the literature revealed those glasses prepared from pure Ag{sub 2}O show a strong linear dependence of the BO{sub 4}{sup {minus}}/BO{sub 3} ratio on AgI content. Most probably, in those glasses prepared with Ag{sub 2}O the Ag{sub 2}O/B{sub 2}O{sub 3} ratio changes with AgI content due to the decomposition of Ag{sub 2}O during melting. This different behavior is associated with AgNO{sub 3} decomposing to Ag{sub 2}O with heating followed by incorporation into the glassy network. For Ag{sub 2}O used directly, it is proposed that it decomposes to Ag metal and O{sub 2}(gas) with heating before it can be incorporated into the borate network. This latter behavior decreases with increasing AgI in the batch composition because AgI lowers the liquidus temperature of the melt considerably. The far-IR analysis of the AgI-doped silver diborate glasses suggests that there are three coordination environments for the Ag{sup +} ions; one with iodide anions and the other two with oxygen ions. It is proposed that the separate oxygen coordination environments for the Ag{sup +} ions arise from one with bridging oxygens of BO{sub 4}{sup {minus}} units, and the other with nonbridging oxygens on BO{sub 3}{sup {minus}} units. Furthermore, it is proposed that the Ag{sup +} ions in the iodide-ion environments progressively agglomerate into disordered regions of AgI, but do not form structures similar to {alpha}-AgI. (Abstract Truncated)

  1. Luminescence properties of Cr-doped silica sol gel glasses

    NASA Astrophysics Data System (ADS)

    Strek, Wieslaw; Lukowiak, Edward; Deren, Przemyslaw J.; Maruszewski, K.; Trabjerg, Ib; Koepke, Czeslaw; Malashkevich, G. E.; Gaishun, Vladimir E.

    1997-11-01

    The emission of Cr-doped silica glass obtained by the sol- gel method is characterized by an orange broad band with a maximum at 610 nm. Its nature is examined by the absorption, excited state absorption, emission, excitation and lifetime measurements over a wide range of temperature and for different concentration of Cr ions. Our measurement show that in spite of fact that the absorption properties of Cr- doped silica sol-gel glass are predominantly associated with Cr4+ centers, the observed in visible range emission can be assigned neither to Cr3+ nor to Cr4+ ions. The discussion of the nature of observed emission was carried out for all possible valencies of the Cr ions. In conclusion is suggested that it may be ascribed to the transitions on the monovalent Cr1+ ion. The reducing agents occurring during the sol-gel process and leading to lowering the Cr valency are discussed.

  2. Excited state cross sections for Er-doped glasses

    NASA Astrophysics Data System (ADS)

    Zemon, Stanley A.; Lambert, Gary M.; Miniscalco, William J.; Davies, Richard W.; Hall, Bruce T.; Folweiler, Robert C.; Wei, Ta-Sheng; Andrews, Leonard J.; Singh, Mahendra P.

    1991-01-01

    Excited-state-absorption (ESA) cross sections were determined for the region between 760 and 900 nm for Er-doped fluorophosphate phosphate and silicate glasses. Measurements were performed on multimode fibers pumping at 647 nm with powers 1 . 5 Wto invert the population into the saturation regime. Over much of the 800-nm band ground-state-absorption (GSA) cross sections are equal to or greater than ESA cross sections. For comparison ESA was also measured for singlemode Al/P-doped silica fiber. The cross sections were incorporated into an amplifier model and the phosphate and fluorophosphate glasses were found to provide higher gain than silica for pumping in the 800-nm band. Photoexcited fluorozirconates were found to have substantial populations in the first four excited states and ESA transitions originating from these states are identified.

  3. Super-Resolution Effect of Semiconductor-Doped Glass

    NASA Astrophysics Data System (ADS)

    Nagase, Toshihiko; Ashida, Sumio; KatsutaroIchihara, KatsutaroIchihara

    1999-03-01

    Semiconductor-doped glass is proposed as a super-resolution layer for future ultra-high-density optical disc systems. It was confirmed that this material system showed very fast response and large transmittance change by laser-beam irradiation when CdSSe-doped glass was used. The rise time of the transmittance change was less than 10 ns and the transmittance change reached 30%. These optical responses were obtained at a power density of the pumped laser beam of 1 MW/cm2. This power density corresponds to the readout power in digital versatile disk-read onlymemory (DVD-ROM) and digital versatile disk-random access memory (DVD-RAM) discs. This material system is regarded as a potential candidate for a super-resolution readout layer that is applicable to both ROM and RAM discs.

  4. Luminescence characteristics of Li₂CO₃-K₂CO₃-H₃BO₃ glasses co-doped with TiO₂/MgO.

    PubMed

    Alajerami, Yasser Saleh Mustafa; Hashim, Suhairul; Ghoshal, Sib Krishna; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Ibrahim, Zuhairi; Kadni, Taiman; Bradley, David Andrew

    2013-12-01

    Understanding the influence of co-dopants in the luminescence enhancement of carbonate glasses is the key issue in dosimetry. A series of borate glasses modified by lithium and potassium carbonate were synthesized by the melt-quenching method. The glass mixture activated with various concentrations of TiO2 and MgO was subjected to various doses of gamma-rays ((60)Co). The amorphous nature of the samples was confirmed by x-ray diffraction (XRD) spectra. The simple glowing curve of the glass doped with TiO2 features a peak at 230°C, whose intensity is maximal at 0.5 mol% of the dopant. The intensity of the glowing curve increases with the concentration of MgO added as a co-dopant up to 0.25 mol%, where it is two times higher than for the material without MgO thermoluminescence properties, including dose response, reproducibility, and fading were studied. The effective atomic number of the material was also determined. Kinetic parameters, such as kinetics order, activation energy, and frequency factor are estimated. The photoluminescence spectra of the titanium-doped glass consist of a prominent peaks at 480 nm when laser excitation at 650 nm is used. A three-fold photoluminescence enhancement and a blue shift of the peak were observed when 0.1% MgO was introduced. In addition, various physical parameters, such as ion concentration, polaron radius and internuclear distances were calculated. The mechanism for the thermoluminescence and photoluminescence enhancements are discussed. PMID:23948307

  5. Upconversion lasing of a Tm3+-doped fluoride glass microsphere

    NASA Astrophysics Data System (ADS)

    Sasaki, Keiji; Fujiwara, Hideki

    1999-07-01

    Upconversion lasing of a thulium-ion-doped zirconium fluoride glass microsphere was demonstrated. The microsphere was pumped by a fundamental wave of a Nd:YAG laser (1064 nm) at room temperature. The lasing emission was observed in 480-nm and 800-nm regions, and their lasing thresholds were determined to be approximately 20 mW and approximately 5 mW, respectively. The application to near-field optical microscopy is also discussed.

  6. Glass transition temperature and conductivity in Li2O and Na2O doped borophosphate glasses

    NASA Astrophysics Data System (ADS)

    Ashwajeet, J. S.; Sankarappa, T.; Ramanna, R.; Sujatha, T.; Awasthi, A. M.

    2015-08-01

    Two alkali doped Borophosphate glasses in the composition, (B2O3)0.2. (P2O5)0.3. (Na2O)(0.5-x). (Li2O)x, where x = 0.05 to 0.50 were prepared by standard melt quenching method at 1200K. Non-crystalline nature was confirmed by XRD studies. Room temperature density was measured by Archimedes principle. DC conductivity in the temperature range from 300K to 575K has been measured. Samples were DSC studied in the temperature range from 423K to 673K and glass transition temperature was determined. Glass transition temperature passed through minima for Li2O con.2centration between 0.25 and 0.30 mole fractions. Activation energy of conduction has been determined by analyzing temperature variation of conductivity determining Arrhenius law. Conductivity passed through minimum and activation passed through maximum for Li2O content from 0.25 to 0.30 mole fractions. Glass transition temperature passed through minimum for the same range of Li2O content. These results revealed mixed alkali effect taking place in these glasses. It is for the first time borophosphate glasses doped with Li2O and Na2O have been studied for density and dc conductivity and, the mixed alkali effect (MAE) has been observed.

  7. Spectroscopic properties of Er3+-doped fluorotellurite glasses

    NASA Astrophysics Data System (ADS)

    Miguel, A.; Al-Saleh, M.; Azkargorta, J.; Morea, R.; Gonzalo, J.; Arriandiaga, M. A.; Fernandez, J.; Balda, R.

    2013-09-01

    In this work we report the spectroscopic properties of Er3+-doped fluorotellurite glasses in the 46.6TeO2-18.2ZnO-35.2ZnF2 system for different ErF3 concentrations between 0.5 and 3 wt%. Absorption and emission spectra and lifetimes have been measured in the visible and near infrared regions. Judd-Ofelt analysis has been performed to estimate the radiative transition probabilities. The high content of ZnF2 in this glass decreases the covalency degree in rare-earth site and results in a lower value of ?2 if compared with zinc tellurite glasses. The infrared emissions at 1532 nm are broader by nearly 30 nm in these glasses if compared to silica glass. This broad emission together with the high values of the stimulated emission cross-section and lifetime of level 4I13/2 make these glasses attractive for broadband amplifiers. The decays from level 4I13/2 are single exponentials for all concentrations which indicates a fast energy diffusion between Er3+ ions. Similar values for the critical radius and energy transfer microparameter are obtained for the different concentrations, which supports the dipole-dipole transfer hypothesis.

  8. Differential scanning calorimetry investigations on Eu-doped fluorozirconate-based glass ceramics

    PubMed Central

    Palick, C.; Ahrens, B.; Henke, B.; Johnson, J. A.; Schweizer, S.

    2010-01-01

    The properties of Eu-doped fluorochlorozirconate (FCZ) glass ceramics upon thermal processing and the influence of Eu-doping on the formation of BaCl2 nanocrystals therein have been investigated. Differential scanning calorimetry indicates that higher Eu-doping shifts the crystallization peak of the nanocrystals in the glass to lower temperatures, while the glass transition temperature remains constant. The activation energy and the thermal stability parameters for the BaCl2 crystallization are determined. PMID:21286235

  9. Blocking effect of crystalglass interface in lanthanum doped barium strontium titanate glassceramics

    SciTech Connect

    Wang, Xiangrong; Zhang, Yong; Baturin, Ivan; Liang, Tongxiang

    2013-10-15

    Graphical abstract: The blocking effect of the crystalglass interface on the carrier transport behavior in the lanthanum doped barium strontium titanate glassceramics: preparation and characterization. - Highlights: La{sub 2}O{sub 3} addition promotes the crystallization of the major crystalline phase. The Z? and M? peaks exist a significant mismatch for 0.5 mol% La{sub 2}O{sub 3} addition. The Z? and M? peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. Crystallite impedance decreases while crystalglass interface impedance increases. La{sub 2}O{sub 3} addition increases blocking factor of the crystalglass interface. - Abstract: The microstructures and dielectric properties in La{sub 2}O{sub 3}-doped barium strontium titanate glassceramics have been investigated by scanning electron microscopy (SEM) and impedance spectroscopy. SEM analysis indicated that La{sub 2}O{sub 3} additive decreases the average crystallite size. Impedance spectroscopy revealed that the positions of Z? and M? peaks are close for undoped samples. When La{sub 2}O{sub 3} concentration is 0.5 mol%, the Z? and M? peaks show a significant mismatch. Furthermore, these peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. With increasing La{sub 2}O{sub 3} concentration, the contribution of the crystallite impedance becomes smaller, while the contribution of the crystalglass interface impedance becomes larger. More interestingly, it was found that La{sub 2}O{sub 3} additive increases blocking factor of the crystalglass interface in the temperature range of 250450 C. This may be attributed to a decrease of activation energy of the crystallite and an increase of the crystalglass interface area.

  10. Laser ablation of silicate glasses doped with transuranic actinides

    SciTech Connect

    Gibson, J.K.; Haire, R.G.

    1998-10-01

    Direct sampling laser ablation plasma mass spectrometry (DS-LAMS) was applied to silica glasses doped with {sup 237}Np, {sup 242}Pu or {sup 241}Am using a unique instrument recently installed into a transuranic glovebox. The primary goal was to assess the utility of mass spectrometry of directly ablated ions for facile evaluation of actinide (An) constituents of silicate glass immobilization matrices used for encapsulation of radionuclides. The instrument and general procedures have been described elsewhere. Three high-purity silicate glasses prepared by a sol-gel process (SG) and one conventional high-temperature (HT; melting point {approx} 1,450 C) borosilicate glass were studied. These glasses comprised the following constituents, with compositions expressed in mass percentages: Np-HT {approx} 30% SiO{sub 2} + 6% B{sub 2}O{sub 3} + 3% BaO + 13% Al{sub 2}O{sub 3} + 10% PbO + 30% La{sub 2}O{sub 3} + 8% {sup 237}NpO{sub 2}; Np-SG {approx} 70% SiO{sub 2} + 30% {sup 237}NpO{sub 2}; Pu-SG {approx} 70% SiO{sub 2} + 30% {sup 242}PuO{sub 2}; Am-SG {approx} 85% SiO{sub 2} + 15% {sup 241}AmO{sub 2}.

  11. Oxyfluorotellurite glasses doped by dysprosium ions. Thermal and optical properties

    NASA Astrophysics Data System (ADS)

    Klimesz, Barbara; Ryba-Romanowski, Witold; Lisiecki, Rados?aw

    2015-04-01

    The paper shows results of investigation of thermal and optical properties of oxyfluorotellurite (65 - x)TeO2-20ZnF2-12Pb2O5-3Nb2O5-xDy2O3 (x = 0.5, 2 and 5) glass systems. Thermal stability and the onset of crystallization of the materials were monitored by differential thermal analysis (DTA). It was found that characteristic parameters, namely glass transition temperatures (Tg), onset of crystallization temperatures (Tc) and thermal stability criteria ?T and H' increased with increasing Dy2O3 content indicating that the incorporation of dysprosium ions improves substantially thermal stability of glass system under study. Optical absorption and emission spectra of Dy3+ ions in oxyfluorotellurite glass were investigated at room temperature in the visible (VIS) and near-infrared (NIR) region. Oscillator strengths, phenomenological Judd-Ofelt (JO) intensity parameters ?2,4,6, radiative transition probabilities, branching ratios and radiative lifetimes of luminescent levels were determined. Decay curves of the 4F9/2 luminescence of incorporated Dy3+ ions were recorded and analysed. Lifetimes and the luminescence dynamics were studied as a function of the Dy2O3 concentration. It was concluded that good thermal stability combined with desirable spectroscopic parameters of investigated dysprosium-doped oxyfluorotellurite glass point at the suitability of this material for the design of UV-excited visible phosphors.

  12. Effect of glass structure on spin Hamiltonian parameters: Cu doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Raj Kumar; Bhatnagar, Anil K.

    2015-06-01

    Cu-doped glasses with compositions [(70TeO2-(30-x)ZnO-xPbO)0.98- (CuO)0.02] (x = 5, 10, 15, 20) were prepared using the melt quenching technique and characterized by EPR. Cu2+ ions are found to be in distorted oxygen octahedral cage and their corresponding spin Hamiltonian (splitting) parameters are deduced for all glasses as a function of increasing PbO. Finally, effect of the matrix on spin Hamiltonian parameters of Cu2+ ions are correlated with the help of EPR and earlier Raman analysis.

  13. Population dynamics in Er3+-doped fluoride glasses

    NASA Astrophysics Data System (ADS)

    Bogdanov, V. K.; Booth, D. J.; Gibbs, W. E.; Javorniczky, J. S.; Newman, P. J.; Macfarlane, D. R.

    2001-05-01

    A detailed study of the energy-transfer processes in Er3+: flouride glasses with doping concentrations of 0.2-18 mol % is presented. Fluorescence wave forms for 11 erbium transitions were measured under 802-nm, 1.5-?m, 975-nm, 520-nm, and 403-nm excitation from a high-energy short-pulse source. The analysis of these data provided a physical understanding of the processes responsible for the temporal behavior of the populations of a large number of energy levels. A comprehensive nine-level rate-equation model of the Er3+ population dynamics in these fluoride glasses is developed. The model performs well in predicting the observed fluorescence behavior of the main fluorescing lines under all pumping conditions. The modeling process allowed 14 ion-ion energy-transfer processes that are important for the population dynamics in these fluoride glasses to be identified and their rate constants obtained. Noticeably, the inclusion of seven three-ion processes was found necessary in order to obtain good fits to the experimental fluorescence wave forms. It was also found that some three-ion processes have a significant effect on the population dynamics of the levels even in lower doping concentrations.

  14. Spectroscopy of the Er-doped lithium tetraborate glasses

    NASA Astrophysics Data System (ADS)

    Padlyak, B. V.; Lisiecki, R.; Ryba-Romanowski, W.

    2016-04-01

    The electron paramagnetic resonance (EPR), optical absorption, and luminescence (emission and excitation) spectra as well as luminescence kinetics of the Er-doped glasses with Li2B4O7 composition were investigated and analysed. The high optical quality glasses with Li2B4O7:Er composition containing 0.5 and 1.0 mol.% Er2O3 were obtained from corresponding polycrystalline compound by standard glass synthesis. The EPR spectroscopy in the 4.2-300 K temperature range and optical spectroscopy at 300 K show that the Er impurity is incorporated into the network of Li2B4O7 glass as Er3+ (4f11, 4I15/2) ions, exclusively. The local structure of the Er3+ luminescence centres in Li sites of the glass network is proposed. Based on the standard Judd-Ofelt theory the oscillator strength (Pcal) and experimental oscillator strength (Pexp) for observed absorption transitions as well as phenomenological intensity parameters (Ω2, Ω4, Ω6) for Er3+ centres in the Li2B4O7:Er glass containing 1.0 mol.% Er2O3 were calculated. Spectroscopic parameters of relevance for laser applications, including emission probabilities of transitions (Wr), branching ratios (β), and radiative lifetime (τrad) have been calculated for main observed emission transitions of the Er3+ centres in Li2B4O7:Er glasses. Experimental and calculated lifetimes were compared and quantum efficiency (η) for green (4S3/2 → 4I15/2 transition) and infrared (4I13/2 → 4I15/2 transition) emission bands has been estimated.

  15. Spectroscopy of vanadium (III) doped gallium lanthanum sulphide chalcogenide glass

    NASA Astrophysics Data System (ADS)

    Hughes, M.; Rutt, H.; Hewak, D.; Curry, R. J.

    2007-01-01

    Vanadium doped gallium lanthanum sulphide glass (V:GLS) displays three absorption bands at 580, 730, and 1155nm identified by photoluminescence excitation measurements. Broad photoluminescence, with a full width at half maximum of 500nm, is observed peaking at 1500nm when exciting at 514, 808, and 1064nm. The fluorescence lifetime and quantum efficiency at 300K were measured to be 33.4?s and 4%, respectively. From the available spectroscopic data, the authors propose the vanadium ions' valence to be 3+ and be in tetrahedral coordination. The results indicate a potential for the development of a laser or optical amplifier based on V:GLS.

  16. Optical properties of Ho3+ doped oxyfluoroborate glass.

    PubMed

    Rai, S B

    2002-06-01

    Ho3+ doped oxyfluoroborate glasses have been prepared with different concentration of holmium. The absorption and the fluorescence spectra have been recorded and used to determine various optical parameters such as oscillator strength, Judd-Ofelt intensity parameters, electric dipole line strengths, transition probability, branching ratio, stimulated emission cross section etc. Lifetime of the 5S2 level has been measured and found to decrease with an increase of the rare earth concentration. Non-radiative transition probability and quantum efficiency of the radiative transitions have also been calculated. PMID:12166725

  17. Spectroscopic properties of Nd3+-doped tungsten-tellurite glasses

    NASA Astrophysics Data System (ADS)

    Costa, F. B.; Yukimitu, K.; Nunes, L. A. O.; Figueiredo, M. S.; Andrade, L. H. C.; Lima, S. M.; Moraes, J. C. S.

    2016-01-01

    In this work, we investigate the spectroscopy properties of neodymium doped tungsten-tellurite glasses prepared in ambient and O2-rich atmospheres. A conversion of TeO4 to TeO3 units was caused by the addition of Nd3+ into the glass, which was confirmed by absorption spectra and by Judd-Ofelt parameter behavior. The relaxation of the 4F3/2 level is dominated by radiative decay and cross-relaxation between Nd3+ and Nd3+ ions. The energy transfer from Nd3+ to the hydroxyl group is negligible when compared to the cross-relaxation. The luminescence quantum efficiency values of the 4F3/2 level decreases as the Nd3+ concentration increases, independently if determined by the Judd-Ofelt method or by the thermal lens technique. The observed reduction in the IR absorption associated to OH groups was not effective to improve the luminescence quantum efficiency.

  18. Energy upconversion in holmium doped lead-germano-tellurite glass

    SciTech Connect

    Kamma, Indumathi; Reddy, B. Rami

    2010-06-15

    Holmium doped lead-germano-tellurite glass was prepared by the melt quenching technique. The Judd-Ofelt intensity parameters were estimated as {Omega}{sub 2}=7.6x10{sup -20}, {Omega}{sub 4}=12.9x10{sup -20}, and {Omega}{sub 6}=2.5x10{sup -20} cm{sup 2}. Radiative transition probabilities and lifetimes were also determined for some of the levels. Room temperature upconversion emissions have been observed from Ho{sup 3+} at 497 nm under 532 nm laser excitation, and at 557 and 668 nm under 762 nm laser excitation. The upconversion emission mechanisms were found to be due to a step wise excitation process. Upconversion emission intensity enhanced in a heat treated glass.

  19. Effect of ytterbium co-doping on erbium clustering in silica-doped glass

    NASA Astrophysics Data System (ADS)

    Kiritchenko, N. V.; Kotov, L. V.; Melkumov, M. A.; Likhachev, M. E.; Bubnov, M. M.; Yashkov, M. V.; Laptev, A. Yu; Guryanov, A. N.

    2015-02-01

    The effect of ytterbium co-doping on erbium ion clustering in silica-based glass was studied. It was experimentally shown that the pump-to-signal conversion efficiency could be significantly increased if the number of Yb3+ ions in the fiber core was 20 times higher than the number of Er3+ ions. Estimations of the number of Er3+ ions in clusters confirmed a decrease in their clustering at high Yb concentrations.

  20. IR optical limiting in europium and thulium doped oxide glasses

    NASA Astrophysics Data System (ADS)

    Wasylak, J.; Ozga, K.; Kityk, I. V.; Kucharski, J.

    2004-07-01

    IR-induced two-photon absorption in PbO-Ga 2O 3-Bi 2O 3-CdO (PGBC) glasses doped by Eu 3+ and Tm 3+ rare earth (RE 3+) ions is reported. A pulsed CO laser ( ?=5.5 ?m, power density up to 3.8 GW/cm 2 per pulse) was applied as a photoinducing IR-light beam. An optical parametrical generator cut from a proustite crystal was used as a source of the fundamental TPA beam within the 3-7.5 ?m spectral range. Absolute values of the TPA coefficients were more than 13% higher compared to corresponding value for other similar glasses: As 2Te 3-CaCl 2-PbCl 2 [J. Appl. Phys. 85 (1999) 425; Phys. Rev. B 60 (1999) 942; Opt. Lasers Technol. 33 (3) (2001) 157; Mater. Lett. 54 (2002)] or Sb 2Se 3-BaCl 2-PbCl 2 [J. Mater. Sci. 35 (1) (2000) 215; Mater. Lett. 49 (2001) 272; J. Non-Cryst. Solids 297 (2002) 285]. The PGBC system possesses a shorter time response (about 12 ps), compared with other IR non-linear optical glasses. We have also established that all non-linear optical susceptibilities are crucially dependent on the type of RE 3+ ion. A maximal value of the TPA is achieved for the PGBC glasses doped by Tm 3+. The TPA values increase significantly below 45 K. We have carried out molecular dynamics and quantum chemical simulations in order to evaluate contribution of electron-phonon anharmonic interactions to the TPA.

  1. Photoluminescence of Eu?-doped glasses with Cu? impurities.

    PubMed

    Jimnez, Jos A

    2015-06-15

    Glasses activated with Eu(3+) ions are attractive as luminescent materials for various photonic applications. Co-doping with copper has been proposed for enhancing material optical properties, but the quenching effect of Cu(2+) impurities on Eu(3+) emission in glass remains largely unexplored. In this work, Eu2O3/CuO-containing barium-phosphate glasses have been prepared by the melt-quench method, and the Eu(3+) photoluminescence (PL) quenching resulting from Eu(3+)?Cu(2+) energy transfer was evaluated. Optical absorption spectroscopy showed that with the increase in CuO concentration the Cu(2+) absorption band resonant with Eu(3+) emission (e.g. (5)D0?(7)F2 transition around 615 nm) developed steadily. As a result, Eu(3+) PL was progressively quenched. Evaluation of the quenching constants as a function of temperature in the 298-673K range showed differences basically within experimental error, consistent with a resonant transfer and lack of phonon-assisted processes. Moreover, analysis of the Eu(3+) emission decay dynamics revealed a strong correlation between the decay rates and Cu(2+) impurity levels. Results imply that for practical applications the levels of Cu(2+) in Eu(3+)/Cu(+)-activated glasses should be reduced if not removed as these will significantly limit device efficiency. PMID:25797222

  2. Photoluminescence of Eu3+-doped glasses with Cu2+ impurities

    NASA Astrophysics Data System (ADS)

    Jimnez, Jos A.

    2015-06-01

    Glasses activated with Eu3+ ions are attractive as luminescent materials for various photonic applications. Co-doping with copper has been proposed for enhancing material optical properties, but the quenching effect of Cu2+ impurities on Eu3+ emission in glass remains largely unexplored. In this work, Eu2O3/CuO-containing barium-phosphate glasses have been prepared by the melt-quench method, and the Eu3+ photoluminescence (PL) quenching resulting from Eu3+ ? Cu2+ energy transfer was evaluated. Optical absorption spectroscopy showed that with the increase in CuO concentration the Cu2+ absorption band resonant with Eu3+ emission (e.g. 5D0 ? 7F2 transition around 615 nm) developed steadily. As a result, Eu3+ PL was progressively quenched. Evaluation of the quenching constants as a function of temperature in the 298-673 K range showed differences basically within experimental error, consistent with a resonant transfer and lack of phonon-assisted processes. Moreover, analysis of the Eu3+ emission decay dynamics revealed a strong correlation between the decay rates and Cu2+ impurity levels. Results imply that for practical applications the levels of Cu2+ in Eu3+/Cu+-activated glasses should be reduced if not removed as these will significantly limit device efficiency.

  3. Spectroscopic properties of Eu3+/Nd3+ co-doped phosphate glasses and opaque glass-ceramics

    NASA Astrophysics Data System (ADS)

    Narro-Garca, R.; Desirena, H.; Lpez-Luke, T.; Guerrero-Contreras, J.; Jayasankar, C. K.; Quintero-Torres, R.; De la Rosa, E.

    2015-08-01

    This paper reports the fabrication and characterization of Eu3+/Nd3+ co-doped phosphate (PNE) glasses and glass-ceramics as a function of Eu3+ concentration. The precursor glasses were prepared by the conventional melt quenching technique and the opaque glass-ceramics were obtained by heating the precursor glasses at 450 C for 30 h. The structural and optical properties of the glass and glass-ceramics were analyzed by means of X-ray diffraction, Raman spectroscopy, UV-VIS-IR absorption spectroscopy, photoluminescence spectra and lifetimes. The amorphous and crystalline structures of the precursor glass and opaque glass-ceramic were confirmed by X-ray diffraction respectively. The Raman spectra showed that the maximum phonon energy decreased from 1317 cm-1 to 1277 cm-1 with the thermal treatment. The luminescence spectra of the glass and glass-ceramic samples were studied under 396 nm and 806 nm excitation. The emission intensity of the bands observed in opaque glass-ceramic is stronger than that of the precursor glass. The luminescence spectra show strong dependence on the Eu3+ ion concentration in the Nd3+ ion photoluminescence (PL) intensity, which suggest the presence of energy transfer (ET) and cross-relaxation (CR) processes. The lifetimes of the 4F3/2 state of Nd3+ ion in Eu3+/Nd3+ co-doped phosphate glasses and glass-ceramics under 806 nm excitation were measured. It was observed that the lifetimes of the 4F3/2 level of Nd3+ of both glasses and glass-ceramics decrease with the increasing Eu3+ concentration. However in the case of opaque glass-ceramics the lifetimes decrease only 16%.

  4. Luminescent properties of Tb3+ and Gd3+ ions doped aluminosilicate oxyfluoride glasses.

    PubMed

    Zuo, Chenggang; Lu, Anxian; Zhu, Ligang; Zhou, Zhihua; Long, Woyun

    2011-11-01

    Tb(3+) and Gd(3+) ions doped lithium-barium-aluminosilicate oxyfluoride glasses have been prepared. The transmission, emission and excitation spectra were measured. It has been found that those Tb(3+)-doped lithium-barium-aluminosilicate oxyfluoride glasses exhibit good UV-excited luminescence. The luminescence intensity of Tb(3+) ion increases for those (Tb(3+), Gd(3+))-codoped glasses. Energy transfer process from Gd(3+) ion to Tb(3+) ion is indicated. PMID:21831699

  5. Intense orange emission in Pr3+ doped lead phosphate glass

    NASA Astrophysics Data System (ADS)

    Mitra, Subrata; Jana, Samar

    2015-10-01

    Spectroscopic properties of one mol% Pr2O3 embedded in 40%PbO-60%P2O5 glass have been investigated at room temperature. From the absorption spectra energy levels of the observed bands are assigned. Using free ion Hamiltonian theoretical values of energy of 13 multiplets of Pr3+ are calculated. Judd-Ofelt intensity parameters have been estimated by including and excluding the hypersensitive transition (3H4?3P2). The best set of Judd-Ofelt parameters are obtained by omitting 3H4?3P2 transition from the calculation. These parameters are used to evaluate the important laser parameters for various emission lines. Our investigation reveals that the present glass may be utilized as a laser active medium corresponding to 3P0?3H4 and 1D2?3H4 transitions respectively, for 484.6 nm (blue) and 599.5 nm (strong orange) emissions. Indirect and direct optical band gap energies of Pr3+ doped lead phosphate glass matrix have also been reported.

  6. Doping of ZnO nanowires using phosphorus diffusion from a spin-on doped glass source

    NASA Astrophysics Data System (ADS)

    Bocheux, A.; Robin, I. C.; Bonaimé, J.; Hyot, B.; Kolobov, A. V.; Mitrofanov, K. V.; Fons, P.; Tominaga, J.; Tamenori, Y.; Feuillet, G.

    2014-05-01

    In this article, we report on ZnO nanowires that were phosphorus doped using a spin on dopant glass deposition and diffusion method. Photoluminescence measurements suggest that this process yields p-doped ZnO. The spatial location of P atoms was studied using x-ray near-edge absorption structure spectroscopy and it is concluded that the doping is amphoteric with P atoms located on both Zn and O sites.

  7. Doping of ZnO nanowires using phosphorus diffusion from a spin-on doped glass source

    SciTech Connect

    Bocheux, A.; Robin, I. C.; Bonaimé, J.; Hyot, B.; Feuillet, G.; Kolobov, A. V.; Fons, P.; Mitrofanov, K. V.; Tominaga, J.; Tamenori, Y.

    2014-05-21

    In this article, we report on ZnO nanowires that were phosphorus doped using a spin on dopant glass deposition and diffusion method. Photoluminescence measurements suggest that this process yields p-doped ZnO. The spatial location of P atoms was studied using x-ray near-edge absorption structure spectroscopy and it is concluded that the doping is amphoteric with P atoms located on both Zn and O sites.

  8. Concentration dependent spectroscopic properties of Sm3+ doped borophosphate glasses

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R.; Marimuthu, K.

    2015-07-01

    A new series of Sm3+ doped borophosphate glasses 50B2O3 + 20Li2CO3 + 10ZnO + 9SrCO3 + (11 - x)P2O5 + xSm2O3 (x = 0.1, 0.25, 0.5, 1 and 2 in wt%) have been prepared by following melt quenching technique. The structural and optical properties of the prepared glasses were characterized through XRD, FTIR, absorption, luminescence and decay spectral measurements. The XRD spectrum exhibit broad diffusion at lower angles which reveal the amorphous nature and the presence of various functional groups such as Psbnd Osbnd P bonds, Bsbnd O vibrations in BO3 units and Psbnd OH and Bsbnd OH bonds in the title glasses were confirmed through the FTIR spectra. The nature of the metal-ligand bonding and the electronic band structure has been investigated using the absorption spectra. The Judd-Ofelt (JO) intensity parameters (?2, ?4 and ?6) were evaluated from the JO theory using the refractive index and the experimental oscillator strength values. The emission spectra exhibit four emission bands in the visible region corresponding to the 4G5/2 ? 6H5/2, 4G5/2 ? 6H7/2, 4G5/2 ? 6H9/2 and 4G5/2 ? 6H11/2 transitions by monitoring an excitation wavelength at 403 nm. The emission spectra have been characterized through Commission International de I'Eclairage (CIE) 1931 chromaticity diagram to explore the dominant emission from the studied glasses. The radiative parameters such as transition probability (AR), branching ratios (?R) and stimulated emission cross-section ( ?PE) were obtained for the emission transitions using JO parameters and the results were discussed and compared with the reported literature.

  9. Effect of doping of Nd3+ ions in BaO-TeO2-B2O3 glasses: A vibrational and optical study

    NASA Astrophysics Data System (ADS)

    Nanda, Kirti; Berwal, Neelam; Kundu, R. S.; Punia, R.; Kishore, N.

    2015-05-01

    Nd3+ ions doped Barium-Tellurite-Borate glasses with compositions xNd2O3 - (100 - x)[0.1BaO-0.4TeO2-0.5B2O3]; x = 0.0, 0.5, 1.0, 1.5 and 2.0 have been prepared by melt-quench technique. The amorphous nature of as-prepared glasses has been confirmed by X-ray diffraction patterns. The density, molar volume and equivalent crystalline volume of the glass samples have been found to increase with the increase in concentration of Nd2O3. FTIR and Raman spectra of the prepared glasses indicate that Nd2O3 acts as glass modifier and as the content of Nd2O3 increases, BO4 structural units are converted into BO3 structural units. The values of optical band gap have been estimated from the fitting of Mott and Davis's model with the experimentally observed absorption spectra. The experimentally observed spectra of absorption coefficient also show good agreement with the hydrogenic excitonic model and the values of different parameters like optical band gap, excitonic binding energy, line width of m = 1 state and line width of continuum have been estimated from theoretical fitting of this model. The values of optical band gap are observed to decrease with increase in concentration of Nd2O3.

  10. Fluoride-modified electrical properties of lead borate glasses and electrochemically induced crystallization in the glassy state

    SciTech Connect

    M'Peko, Jean-Claude; Souza, Jose E. de; Rojas, Seila S.; Hernandes, Antonio C.

    2008-02-15

    Lead fluoroborate glasses were prepared by the melt-quenching technique and characterized in terms of (micro)structural and electrical properties. The study was conducted on as prepared as well as temperature- and/or electric field-treated glass samples. The results show that, in the as-prepared glassy-state materials, electrical conductivity improved with increasing the PbF{sub 2} glass content. This result involves both an increase of the fluoride charge carrier density and, especially, a decrease of the activation energy from a glass structure expansion improving charge carrier mobility. Moreover, for the electric field-treated glass samples, surface crystallization was observed even below the glass transition temperature. As previously proposed in literature, and shown here, the occurrence of this phenomenon arose from an electrochemically induced redox reaction at the electrodes, followed by crystallite nucleation. Once nucleated, growth of {beta}-PbF{sub 2} crystallites, with the indication of incorporating reduced lead ions (Pb{sup +}), was both (micro)structurally and electrically detectable and analyzed. The overall crystallization-associated features observed here adapt well with the floppy-rigid model that has been proposed to further complete the original continuous-random-network model by Zachariasen for closely addressing not only glasses' structure but also crystallization mechanism. Finally, the crystallization-modified kinetic picture of the glasses' electrical properties, through application of polarization/depolarization measurements originally combined with impedance spectroscopy, was extensively explored.

  11. Photoluminescence in Ga/Bi co-doped silica glass.

    PubMed

    Razdobreev, Igor; El Hamzaoui, Hicham; Arion, Vladimir B; Bouazaoui, Mohamed

    2014-03-10

    Bismuth-Gallium co-doped silica glass fiber preform was prepared from nano-porous silica xerogels using a conventional solution doping technique with a heterotrinuclear complex and subsequent sintering. Ga-connected optical Bismuth active center (BAC) was identified as the analogue of Al-connected BAC. Visible and infrared photoluminescence (PL) were investigated in a wide temperature range of 1.46 - 300 K. Based on the results of the continuous wave (CW) and time resolved (TR) spectroscopy we identify the centers emitting in the spectral region of 480 - 820 nm as Bi(+) ions. The near infrared (NIR) PL around 1100 nm consists of two bands. While the first one can be ascribed to the transition in Bi(+) ion, the second band is presumably associated to defects. We put in evidence the energy transfer (ET) between Bi(+) ions and the second NIR emitting center via quadrupole-quadrupole and dipole-quadrupole mechanisms of interactions. Finally, we propose the energy level diagram of Bi(+) ion interacting with this defect. PMID:24663907

  12. Synthesis and Structural Characterization of Niobium Doped Lead-Telluride Glass-Ceramics

    NASA Astrophysics Data System (ADS)

    Sathish, M.; Eraiah, B.

    2015-02-01

    The basic glasses with composition (70-x) TeO2-30PbO-xNb2O5 (where x=0.1 mol % and 0.2 mol %) were prepared by melt quenching method and heat treated at 280C for 30 min. The samples becoming glass ceramics was confirmed by SEM. The XRD parameters such as crystallite size of these glass ceramics decreases as increase the impurity and is the order of 184-109A. However, micro strain (?) and dislocation density (?) increases. Glass transition and thermal stability estimated from DSC measurements and it has been found that both increase with increasing of impurity. Infrared Absorption spectra were measured for TeO2 glass and glass ceramic doped with Nb2O5. The recorded bands attributed to the different modes of vibration and stretching of Te-O band. Optical Absorption spectra of TeO2-PbO- Nb2O5 system shows that the absorption edge has a tail extending towards the lower energies and shifts towards for higher energies for rare earths-doped glass-ceramics. The degree of the edge shift was found to depend on the structural rearrangement and the relative concentrations of the glass basic units. The general appearance of the absorption spectra of these rare earth doped TeO2 glasses are similar to the spectra observed for other glasses doped with the same kind of rare earth oxides.

  13. Thermal, structural and spectroscopic properties of heavy metal oxide glass and glass-ceramics doped with Er3+ ions

    NASA Astrophysics Data System (ADS)

    Ragin, Tomasz; Zmojda, Jacek; Kochanowicz, Marcin; Miluski, Piotr; Jelen, Piotr; Sitarz, Maciej; Dorosz, Dominik

    2015-09-01

    In this paper, bismuth-germanate oxide glass doped with erbium ions has been synthesized. Composition of the glass has been chosen in terms of the low phonon energy and good transparency in the infrared region. Transparent glass-ceramics sample has been prepared by controlled crystallization process. Fourier transform infrared spectroscopy (FTIR) has been used to determinate structural properties of samples. The absorption coefficient, the luminescence intensity in visible and infrared region and the differential scanning calorimetry have been examined. Difference in the emission intensity and shape of the luminescence bands indicates the presence of crystalline phases in obtained glass-ceramics sample.

  14. Optical absorption and self activated upconversion fluorescence spectra of Tm 3+ ions in antimony borate glass systems

    NASA Astrophysics Data System (ADS)

    Sudhakar, K. S. V.; Satyanarayana, T.; Srinivasa Rao, L.; Srinivasa Reddy, M.; Veeraiah, N.

    2008-06-01

    Optical absorption and fluorescence spectra of Tm 3+ ions in Sb 2O 3-B 2O 3 glasses mixed with three different modifier oxides viz., PbO, CaO and ZnO have been recorded at room temperature. The radiative transition probabilities and branching ratios evaluated for various luminescent transitions suggested the highest value for G41?H63 transition among various other transitions in all the three glass systems. The analysis of these data further suggested that the comparatively high non-radiative losses in ZnO mixed glasses. We have also demonstrated the upconversion from red to blue emission (from D21 and G41 emitting levels) in these glasses with two step absorption mechanism using F43 and H43 levels as intermediate levels.

  15. In vitro study of manganese-doped bioactive glasses for bone regeneration.

    PubMed

    Miola, Marta; Brovarone, Chiara Vitale; Maina, Giovanni; Rossi, Federica; Bergandi, Loredana; Ghigo, Dario; Saracino, Silvia; Maggiora, Marina; Canuto, Rosa Angela; Muzio, Giuliana; Vern, Enrica

    2014-05-01

    A glass belonging to the system SiO2-P2O5-CaO-MgO-Na2O-K2O was modified by introducing two different amounts of manganese oxide (MnO). Mn-doped glasses were prepared by melt and quenching technique and characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) observation and energy dispersion spectrometry (EDS) analysis. In vitro bioactivity test in simulated body fluid (SBF) showed a slight decrease in the reactivity kinetics of Mn-doped glasses compared to the glass used as control; however the glasses maintained a good degree of bioactivity. Mn-leaching test in SBF and minimum essential medium (MEM) revealed fluctuating trends probably due to a re-precipitation of Mn compounds during the bioactivity process. Cellular tests showed that all the Mn-doped glasses, up to a concentration of 50 ?g/cm(2) (?g of glass powders/cm(2) of cell monolayer), did not produce cytotoxic effects on human MG-63 osteoblasts cultured for up to 5 days. Finally, biocompatibility tests demonstrated a good osteoblast proliferation and spreading on Mn-doped glasses and most of all that the Mn-doping can promote the expression of alkaline phosphatase (ALP) and some bone morphogenetic proteins (BMPs). PMID:24656359

  16. Investigations on spectroscopic properties of Er3+-doped Li-Zn fluoroborate glass

    NASA Astrophysics Data System (ADS)

    Thomas, Sunil; Sajna, M. S.; George, Rani; Rasool, Sk. Nayab; Joseph, Cyriac; Unnikrishnan, N. V.

    2015-09-01

    Er3+-doped Li-Zn fluoroborate glass was synthesized via melt quenching technique. Optical properties of the glass were investigated by UV-Vis-NIR absorption and emission spectra. To evaluate the nature of Er3+-ligand bond in the glass network, nephelauxetic ratios and bonding parameter were calculated. Judd-Ofelt analysis and hence the radiative properties of the present glass system were evaluated for ascertaining the suitability of the glass for laser applications and compared those with the emission spectra. Absorption cross-sections have been calculated from the absorption spectrum and stimulated emission cross-sections were estimated using McCumber theory for 4I13/2 ↔ 4I15/2 transitions. The results of the present glass were compared with those obtained for some other Er3+-doped glass systems.

  17. Investigations on spectroscopic properties of Er(3+)-doped Li-Zn fluoroborate glass.

    PubMed

    Thomas, Sunil; Sajna, M S; George, Rani; Rasool, Sk Nayab; Joseph, Cyriac; Unnikrishnan, N V

    2015-09-01

    Er(3+)-doped Li-Zn fluoroborate glass was synthesized via melt quenching technique. Optical properties of the glass were investigated by UV-Vis-NIR absorption and emission spectra. To evaluate the nature of Er(3+)-ligand bond in the glass network, nephelauxetic ratios and bonding parameter were calculated. Judd-Ofelt analysis and hence the radiative properties of the present glass system were evaluated for ascertaining the suitability of the glass for laser applications and compared those with the emission spectra. Absorption cross-sections have been calculated from the absorption spectrum and stimulated emission cross-sections were estimated using McCumber theory for (4)I13/2↔(4)I15/2 transitions. The results of the present glass were compared with those obtained for some other Er(3+)-doped glass systems. PMID:25863458

  18. Enhanced broadband near-infrared luminescence of Bi-doped oxyfluoride glasses.

    PubMed

    Xu, Beibei; Tan, Dezhi; Zhou, Shifeng; Hong, Zhanglian; Sharafudeen, Kaniyarakkal N; Qiu, Jianrong

    2012-12-17

    Broadband near-infrared luminescence covering 900 to 1600 nm has been observed in Bi-doped oxyfluoride silicate glasses. The partial substitution of fluoride for oxide in Bi-doped silicate glasses leads to an increase of the intensity and lifetime of the near-infrared luminescence and blue-shift of the near-infrared emission peaks. Both Bi-doped silicate and oxyfluoride silicate glasses show visible luminescence with blue, green, orange and red emission bands when excited by ultra-violet light. Careful investigation on the luminescence properties indicates that the change of near-infrared luminescence is related to optical basicity, phonon energy of the glass matrix and crystal field around Bi active centers. These results offer a valuable way to control the luminescence properties of Bi-doped materials and may find some applications in fiber amplifier and fiber laser. PMID:23263148

  19. Photonic bandgap single-mode optical fibre with ytterbium-doped silica glass core

    SciTech Connect

    Egorova, O N; Semenov, S L; Vel'miskin, V V; Dianov, Evgenii M; Salganskii, M Yu; Yashkov, M V; Gur'yanov, Aleksei N

    2011-01-24

    A photonic bandgap fibre with an ytterbium-doped silica glass core is fabricated and investigated. The possibility of implementing single-mode operation of such fibres in a wide spectral range at a large (above 20 {mu}m) mode field diameter makes them promising for fibre lasers and amplifiers. To ensure a high quality of the beam emerging from the fibre, particular attention is paid to increasing the optical homogeneity of the ytterbium-doped core glass. (optical fibres)

  20. Effect of 1 MeV electrons on ceria-doped solar cell cover glass

    NASA Technical Reports Server (NTRS)

    Haynes, G. A.

    1973-01-01

    The effect of 1 MeV electrons on the transmission properties of 1.5-percent ceria-doped solar cell cover glass was studied. Samples of doped and undoped cover glass and synthetic fused silica were irradiated with a total integrated flux of 10 to the 15th power e/sq cm. Wideband transmission and spectral transmission measurements were made before and after irradiation. The results indicate that 1.5-percent ceria-doped cover glass is much less sensitive to radiation induced discoloration than undoped cover glass. Consequently, the glass is comparable to synthetic fused silica when used as a radiation resistant solar cell cover for many space missions.

  1. Effects of CuO co-doping on ?-ray irradiation resistance of active ions doped phosphate glasses

    NASA Astrophysics Data System (ADS)

    Zhang, Zhihuan; Baccaro, Stefania; Cemmi, Alessia; Shen, Wei; Chen, Guorong

    2013-09-01

    The effect of copper ion doping on the ?-ray irradiation resistance of Mn2+ and Pr3+ doped phosphate glasses has been studied. UV-visible transmission spectra and photoluminescence spectra have been measured before and after ?-irradiation to characterize the radiation-induced defects. The electron paramagnetic resonance spectra of the irradiated samples with, and without Cu ions have been compared to show the ability of Cu ions to suppress the generation of radiation-induced color centers. The differential transmission spectra and the radiation-induced absorption coefficients have also been calculated for discussion of the observed phenomena. The much improved ?-irradiation resistance of Mn2+ and Pr3+ doped phosphate glasses has been demonstrated through CuO co-doping.

  2. Study of vibrational spectroscopy, linear and non-linear optical properties of Sm3+ ions doped BaO-ZnO-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Nanda, Kirti; Kundu, R. S.; Sharma, Sarita; Mohan, Devendra; Punia, R.; Kishore, N.

    2015-07-01

    Samarium oxide doped Barium-Zinc-Borate glasses with compositions xSm2O3-(100-x)[0.1BaO-0.4ZnO-0.5B2O3]; x = 0.0, 0.5, 1.0, 1.5 and 2.0 have been prepared by melt quench technique. The amorphous nature of as-prepared glasses has been ascertained by X-ray diffraction patterns. The observed values of density and molar volume of the glass samples are found to increase with the increase in concentration of Sm2O3. Fourier Transform Infrared spectra of the prepared glasses indicate that Sm2O3 acts as glass modifier. With the increase in Sm2O3 content, BO4 structural units start converting into BO3 structural units. The values of optical energy band gap (Eg), estimated from Tauc's plots, are observed to decrease with the increase in Sm2O3 content. The nonlinear optical properties of glass samples have been investigated by Z-scan method with nanosecond pulsed laser at ˜532 nm in both open and close aperture geometries. The values of two photon absorption coefficient (β) and nonlinear refractive index (n2) have been estimated by fitting of experimentally observed data with theoretical models and both are found to increase with the increase in Sm3+ ions concentration in the glass matrix. The total third order nonlinear susceptibility (χ(3)) have been calculated and observed to increase with the increase in Sm3+ ions concentration.

  3. Nonlinear-optic and ferroelectric behavior of lithium borate-strontium bismuth tantalate glass-ceramic composite

    NASA Astrophysics Data System (ADS)

    Senthil Murugan, G.; Varma, K. B. R.; Takahashi, Yoshihiro; Komatsu, Takayuki

    2001-06-01

    Transparent glasses in the system (100-x) Li2B4O7-xSrBi2Ta2O9 (0?x?20) were fabricated via a splat-quenching technique. The glassy nature of the as-quenched samples was established by differential thermal analyses. X-ray powder diffraction and transmission electron microscopic studies confirmed the amorphous nature of the as-quenched and crystallinity (40 nm) in the heat-treated (glass-ceramic) samples. The dielectric constant (?r) of the glass-ceramic composite (x=20, heat treated at 773 K/8 h) was in between that of the parent host glass (Li2B4O7) and strontium bismuth tantalate ceramics in the frequency range 100 Hz-40 MHz at 300 K. These exhibited intense second-harmonic generation and a ferroelectric hysteritic behavior (P vs E loops) at 300 K. The coercive field (Ec) and the remnant polarization (Pr) were 1053 V/cm and 0.483 ?C/cm2, respectively.

  4. Nonlinear-optic and ferroelectric behavior of lithium borate{endash}strontium bismuth tantalate glass{endash}ceramic composite

    SciTech Connect

    Senthil Murugan, G.; Varma, K. B. R.; Takahashi, Yoshihiro; Komatsu, Takayuki

    2001-06-18

    Transparent glasses in the system (100{endash}x) Li{sub 2}B{sub 4}O{sub 7}{endash}xSrBi{sub 2}Ta{sub 2}O{sub 9} (0{le}x{le}20) were fabricated via a splat-quenching technique. The glassy nature of the as-quenched samples was established by differential thermal analyses. X-ray powder diffraction and transmission electron microscopic studies confirmed the amorphous nature of the as-quenched and crystallinity (40 nm) in the heat-treated (glass{endash}ceramic) samples. The dielectric constant ({epsilon}{sub r}) of the glass{endash}ceramic composite (x=20, heat treated at 773 K/8 h) was in between that of the parent host glass (Li{sub 2}B{sub 4}O{sub 7}) and strontium bismuth tantalate ceramics in the frequency range 100 Hz{endash}40 MHz at 300 K. These exhibited intense second-harmonic generation and a ferroelectric hysteritic behavior (P vs E loops) at 300 K. The coercive field (E{sub c}) and the remnant polarization (P{sub r}) were 1053 V/cm and 0.483 {mu}C/cm2, respectively. {copyright} 2001 American Institute of Physics.

  5. Study on the preparation and properties of silver-doped phosphate antibacterial glasses (Part I)

    NASA Astrophysics Data System (ADS)

    Ahmed, A. A.; Ali, A. A.; Mahmoud, Doaa A. R.; El-Fiqi, A. M.

    2011-05-01

    Silver-doped phosphate antibacterial glasses were prepared by the melting method. The antibacterial effects of some undoped and silver-doped glasses of compositions 65P 2O 5-10CaO-(25- x) Na 2O, 70P 2O 5-20CaO-(10- x) Na 2Oand (70- x) P 2O 5-30CaO, (where x = 0, 0.5, 1.2 Ag 2O), against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli micro-organisms using agar disk-diffusion assays were investigated. The structures of some glasses were studied by XRD, FT-IR, and UV-VIS spectroscopy. The variation of pH with dissolution rate was studied. The tested silver-free and silver-doped glasses demonstrated different antibacterial effects against the tested micro-organisms. For silver-free glasses, an increase in inhibition zone diameter (zone of no bacterial growth) was seen with the decrease in water pH. Silver-doped glasses showed an increase in inhibition zone diameter with increasing Ag 2O content. The low pH produced by glass dissolution was certainly a critical factor for glass antibacterial effect. The more the phosphate ions released the lower is the pH and the greater the antibacterial effect.

  6. Luminescence properties of Tb(3+)-doped borosilicate scintillating glass under UV excitation.

    PubMed

    Zuo, Chenggang; Zhou, Zhihua; Zhu, Ligang; Xiao, Anguo; Chen, Yuandao; Zhang, Xiangyang; Zhuang, Yongbing; Li, Xiaoyang; Ge, Qizhi

    2015-08-01

    Transparent Li?O-BaO-La?O?-Al?O?-B?O?-SiO? glasses doped with Tb(3+) ion were prepared by high temperature melting method. Luminescence properties of Tb(3+)-doped borosilicate glasses have been investigated by transmission, excitation, emission and luminescence decay measurements. The transmission spectrum shows the glass has good transmittance in the visible region. Under the 236 nm UV excitation the intense green emission from (5)D? level is observed in Tb(3+)-doped borosilicate glass, comparable in intensity to the violet-blue emission starting from the (5)D? level. The green emission intensity of Tb(3+) ion firstly increases and then decreases with the decreasing B?O?/SiO? ratio in glass matrix. (5)D??(7)FJ (J=6, 5, 4 and 3) transitions of Tb(3+) ion in borosilicate glass are greatly enhanced with increasing concentration of Tb(3+) through the cross relaxation [Tb(3+) ((5)D?)+Tb(3+) ((7)F6)?Tb(3+) ((5)D?)+Tb(3+) ((7)F?)] between two Tb(3+) ions. Luminescence decay time of 2.13 ms is obtained for the emission transitions starting from (5)D? level in 2.5Li?O-20BaO-20La?O?-2.5Al?O?-20B?O?-35SiO?-0.5Tb?O? glass. The results show that Tb(3+)-doped borosilicate glasses would be potential candidates for scintillating material for static X-ray imaging. PMID:25863031

  7. Growth and characterization of pure and 1, 10 phenanthraline doped potassium penta borate (KB5) single crystals

    NASA Astrophysics Data System (ADS)

    Prabha, K.; Babu, M. Ramesh; Sagayaraj, P.

    2013-05-01

    We concentrate on the low temperature slow solvent evaporation method and characterization of pure and 1, 10 phenanthraline doped KB5 and describe its potential as a non-linear optical material. The grown crystal has been subjected to single crystal X-ray diffraction analysis to identify the unit cell parameters and crystal system. The presence of carbon, hydrogen and oxygen content were confirmed by CHN analysis. The Kurtz's-Perry powder SHG efficiency was determined for both pure and 1,10 phenanthraline doped KB5 crystals as 1.6 and 2.2 times than that of pure KDP. Surface morphology of the pure and doped KB5 crystals has been found to be Scanning Electron Microscopic technique (SEM).

  8. Thermal analysis and luminescence of phospho-tellurite glass doped with NdF3

    NASA Astrophysics Data System (ADS)

    Iwanowicz, Kamil; Dorosz, Dominik; ?mojda, Jacek; Kochanowicz, Marcin

    2015-09-01

    In the paper thermal and luminescence properties of phospho-tellurite glass and glass after thermal treatment doped with NdF3 were presented. The crystallization kinetic of the main crystallization peaks of glass was investigated using differential scanning calorimetry (DSC). The value of the activation energy for crystalline phase (Ec 54,21 +/- 5 kJ mol-1) was calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), Starink and Tang methods. The glass-ceramic was obtained by heat treatment method. The luminescence transitions from levels 4F5/2 --> 4I9/2 (878 nm), 4F3/2-->4I11/2 (1058 nm), and 4F3/2 --> 4I13/2 (1330 nm) in glass and glass-ceramic doped NdF3 were compered.

  9. Raman and Photoluminescence Spectroscopy of Er(3+) Doped Heavy Metal Oxide Glasses

    NASA Technical Reports Server (NTRS)

    Dyer, Keith; Pan, Zheng-Da; Morgan, Steve

    1997-01-01

    The potential applications of rare-earth ion doped materials include fiber lasers which can be pumped conveniently by infrared semiconductor laser diodes. The host material systems most widely studied are fluoride crystals and glasses because fluorides have low nonradiative relaxation rates due to their lower phonon energies. However, the mechanical strength, chemical durability and temperature stability of the oxide glasses are generally much better than fluoride glasses. The objective of this research was to investigate the optical and spectroscopic properties of Er(3+)-doped lead-germanate and lead-tellurium-germanate glasses. The maximum vibrational energy of lead-tellurium-germanate glasses are in the range of 740-820/cm, intermediate between those of silicate (1150/cm) and fluoride (530/cm) glasses.

  10. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    SciTech Connect

    Sushama, D.

    2014-10-15

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er{sub 2}O{sub 3} doped TeO{sub 2}‐WO{sub 3}‐La{sub 2}O{sub 3} Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

  11. Up-conversion losses in different erbium-doped laser glasses

    NASA Astrophysics Data System (ADS)

    Denker, B. I.; Galagan, B. I.; Sverchkov, S. E.

    2015-08-01

    Up-conversion can be the main mechanism of energy losses in laser glasses with high concentration of erbium ions. This investigation is devoted to the evaluation of up-conversion parameters in several phosphate and silicate Er-doped glasses. Analysis of the luminescent lifetime shortening at high excitation level has shown that the up-conversion parameters in different glasses can differ by an order of magnitude. The smallest up-conversion was observed in Ba crown silicate glass and Li-Ln-phosphate glass.

  12. Passive laser Q switches made of glass doped with oxidised nanoparticles of copper selenide

    SciTech Connect

    Yumashev, K V

    2000-01-31

    Passive Q switching of Nd{sup 3+}:YAG ({lambda} = 1060 nm) and YAlO{sub 3}:Nd{sup 3+} (1340 nm) lasers, as well as of an Er{sup 3+} (1540 nm) glass laser was realised by using glass doped with oxidised nanoparticles of copper selenide. Nonlinear optical properties of the nanoparticles (radius of 25 nm) in a glass matrix were studied by the picosecond absorption spectroscopy technique. (control of laser radiation parameters)

  13. Laser induced breakdown spectroscopy diagnosis of rare earth doped optical glasses

    SciTech Connect

    Dwivedi, Y.; Thakur, S. N.; Rai, S. B.

    2010-05-01

    In the present work, rare earth (Nd, Eu, Er, Ho) doped oxyfluoroborate glasses were studied using laser induced breakdown spectroscopy (LIBS) technique. It has been observed that rare earth elements other than the doped one also reveal their presence in the spectrum. In addition the spectral lines of elements constituting the glass matrix have also been observed. Different plasma parameters such as plasma temperature and electron density have been estimated. It is concluded that the LIBS is a potential technique to identify simultaneously the light elements (B, O, F) as well as the heavy elements (Fe, Ba, Ca, Eu, Nd, Ho, Er) present in optical glasses.

  14. Low-threshold lasing at 1975 nm in thulium-doped tellurite glass microspheres.

    PubMed

    Vanier, Francis; Ct, Franois; Amraoui, Mohammed El; Messaddeq, Youns; Peter, Yves-Alain; Rochette, Martin

    2015-11-15

    Thulium-doped (Tm-doped) tellurite glass microspheres are used as laser media. Emission lines at wavelengths near 1975 nm are observed. The onset of laser emission is achieved with 8.6 and 30 ?W of coupled pump power and injected pump power, respectively, at a wavelength of 1554 nm. To the authors' knowledge, these are the lowest laser threshold values recorded for a Tm-doped tellurite glass microcavity. Intrinsic Q-factors above 10(6) for the undoped tellurite glass microspheres assert the quality of the fabrication processes. An optical intrinsic Q-factor comparison between Tm-doped tellurite and undoped tellurite microspheres shows that ion absorption is the dominant loss source at pump wavelengths. Lower lasing threshold powers and higher power conversion are observed at longer pump wavelengths in agreement with theoretical models. PMID:26565841

  15. Synthesis, thermal and photoluminescent properties of ZnSe- based oxyfluoride glasses doped with samarium

    NASA Astrophysics Data System (ADS)

    Kostova, I.; Okada, G.; Pashova, T.; Tonchev, D.; Kasap, S.

    2014-12-01

    Rare earth (RE) doped glasses and glass ceramic materials have recently received considerable attention because of their potential or realized applications as X-ray intensifying screens, phosphors, detectors, waveguides, lasers etc. [1]. In this work, we present a new RE doped ZnO-ZnSe-SrF2-P2O5-B2O3-Sm2O3-SmF3 (ZSPB) glass system synthesized by melt quenching technique. The resulting glasses were visually fully transparent and stable with glass the transition temperatures around 530°C. The thermal properties of this glass system were characterized by Modulated Differential Scanning Calorimetry (MDSC) measurements before and after annealing at 650°C. We have characterized these glasses by Raman spectroscopy and photoluminescence (PL) measurements over the UV-VIS range using light emitting diodes (LED) and laser diodes (LD) excitation sources. We have also irradiated thermally treated and non-treated glass samples by X-rays and have studied the resulting PL. We discuss the results in terms of previously reported models for Sm-doped Zn-borophosphate oxide, oxyfluoride and oxyselenide glasses.

  16. Multi-functionality of luminescent glasses for energy applications

    NASA Astrophysics Data System (ADS)

    Steudel, F.; Loos, S.; Ahrens, B.; Schweizer, S.

    2015-09-01

    Rare-earth-(RE) doped barium borate glasses are investigated for their potential use as photon downshifting cover glasses for CdTe solar cells and as converters for white light-emitting diodes (LEDs). The glasses are doped with trivalent RE ions such as Eu3+ and Tb3+, resulting in an intense luminescence in the red (Eu3+) and green (Tb3+) spectral range upon excitation in the ultraviolet and blue ranges. Doping the glasses with two different RE ions enables broader absorption, which is necessary for both photovoltaic applications and for the appropriate color mixing needed for use in white LEDs. Though the single-doped cover glasses already reveal a slight increase in the short-circuit current density of CdTe solar cells, the double-doped glasses allow for even higher efficiency gains due to the significantly broader spectral range for absorption. For an Eu3+/Tb3+ double-doped glass with an RE doping level of 1 at.% each, an efficiency increase of 1.32% can be achieved. Furthermore, the Eu3+/Tb3+ double-doped glasses enable appropriate color mixing in the green-to-red spectral range by varying the RE doping level accordingly.

  17. In-volume waveguides by fs-laser direct writing in rare-earth-doped fluoride glass and phosphate glass

    NASA Astrophysics Data System (ADS)

    Esser, D.; Wortmann, D.; Gottmann, J.

    2009-02-01

    Refractive index modifications are fabricated in the volume of rare-earth-doped glass materials namely Er- and Pr-doped ZBLAN (a fluoride glass consisting of ZrF4, BaF2, LaF3, AlF3, NaF), an Er-doped nano-crystalline glass-ceramic and Yb- and Er-doped phosphate glass IOG. Femtosecond laser radiation (?=500fs, ?=1045nm, f=0.1-5MHz) from an Ybfiber laser is focused with a microscope objective in the volume of the glass materials and scanned below the surface with different scan velocities and pulse energies. Non-linear absorption processes like multiphoton- and avalanche absorption lead to localized density changes and the formation of color centers. The refractive index change is localized to the focal volume of the laser radiation and therefore, a precise control of the modified volume is possible. The width of the written structures is analyzed by transmission light microscopy and additionally with the quantitative phase microscopy (QPm) software to determine the refractive index distribution perpendicular to a waveguide. Structures larger than 50?m in width are generated at high repetition rates due to heat accumulation effects. In addition, the fabricated waveguides are investigated by far-field measurements of the guided light to determine their numerical apertures. Using interference microscopy the refractive index distribution of waveguide cross-sections in phosphate glass IOG is determined. Several regions with an alternating refractive index change are observed whose size depend on the applied pulse energies and scan velocities.

  18. Enhanced broadband near-infrared luminescence in Bi-doped glasses by co-doping with Ag

    NASA Astrophysics Data System (ADS)

    Xu, Beibei; Chen, Ping; Zhou, Shifeng; Hong, Zhanglian; Hao, Jianhua; Qiu, Jianrong

    2013-05-01

    Enhanced broadband near-infrared luminescence has been observed in Bi-doped oxyfluoride glasses excited from UV to near-infrared regions with the addition of AgCl. Enhancement factors depend greatly on excitation wavelength and maximal enhancement factor over three times occurs at the excitation wavelength around 320, 640, and 800 nm. Ag species play dual functions. The mechanism of the enhancement is discussed in depth combing the energy transfer from Ag+, molecular-like, nonplasmonic Ag species, Bi3+ and Bi2+ to near-infrared bismuth active centers, and the redox reaction of Bi species with Ag species. These results offer a valuable way to enhance the near-infrared luminescence efficiency of Bi-doped glasses, and the dual functions of Ag species may also be employed to enhance luminescence of rare-earth and transition metal ions doped materials.

  19. X-ray absorption studies of gamma irradiated Nd doped phosphate glass

    NASA Astrophysics Data System (ADS)

    Rai, V. N.; Rajput, Parasmani; Jha, S. N.; Bhattacharyya, D.

    2015-06-01

    This paper presents the X-ray absorption near edge structure (XANES) studies of Nd doped phosphate glasses before and after gamma irradiation. The intensity and location of LIII edge white line peak of Nd changes depending on its concentration as well as on the ratio of O/Nd in the glass matrix. The decrease in the peak intensity of white line after gamma irradiation indicates towards reduction of Nd3+ to Nd2+ in the glass matrix, which increases with an increase in the doses of gamma irradiation. Similarity in the XANES spectra of Nd doped phosphate glasses and Nd2O3 suggests that coordination geometry around Nd3+ in glass samples may be identical to that of Nd2O3.

  20. 2.7 μm emission in heavy metal oxide glasses doped with erbium ions

    NASA Astrophysics Data System (ADS)

    Ragin, Tomasz; Zmojda, Jacek; Kochanowicz, Marcin; Miluski, Piotr; Jelen, Piotr; Sitarz, Maciej; Dorosz, Dominik

    2015-12-01

    In this paper, heavy metal oxide glasses based on bismuth, germanate and gallium elements doped with Er3+ have been synthesized. Composition of glass matrix has been developed in terms of low phonon energy (724 cm-1), low absorption coefficient in the infrared region (1.2 cm-1), good mechanical and chemical properties. Synthesis of glasses has been performed under a low vacuum condition, which has reduced the OH- ions to 50 ppm. Glasses were doped with (0.25 - 1 mol%) Er2O3 to obtain emission at the wavelength of 2.7 μm (4I11/2 → 4I13/2) under 980 nm laser diode excitation. Obtained results demonstrate that developed heavy metal oxide glass is an attractive material for mid-infrared applications.

  1. Short vertical tube furnace for the fabrication of doped glass microsphere lasers

    NASA Astrophysics Data System (ADS)

    Ward, Jonathan M.; Wu, Yuqiang; Khalfi, Krimo; Chormaic, Síle Nic

    2010-07-01

    We report on the design of an electric tube furnace that can be used for the fabrication of doped glass microsphere lasers. The tube furnace has a short hot zone of length 133 mm and is based on a quartz tube design. Doped laser glass particles, specifically Er:Yb phosphate glass (IOG-2), of ˜1 μm diameter are blown into the furnace using a 60 ml syringe and microspheres ranging in size from 10 to 400 μm are collected at the output of the tube furnace in a Petri dish. The furnace operates at a wall temperature of ˜900 °C and is capable of making microspheres from glasses with glass transition temperatures of at least 375 °C. High quality (Q ˜105) whispering gallery modes have been excited within the microspheres by optically pumping at 978 nm via a tapered optical fiber.

  2. Optical properties and laser parameters of Nd 3+-doped flouride glasses

    NASA Astrophysics Data System (ADS)

    Tesar, A.; Campbell, J.; Weber, M.; Weinzapfel, C.; Lin, Y.; Meissner, H.; Toratani, H.

    1992-09-01

    Optical properties and laser parameters for 27 Nd 3+-doped flouride glasses are reported. Included are glasses based on zirconium flouride, hafnium flouride, and aluminum flouride and other glasses formed from mixtures of several heavy metal flourides. Measurements were made of the 4F 3/2? 4I 11/2 flourescence spectra and the concentration-dependent flourescence decays. Judd-Ofelt intensity parameters were derived from absorption spectra and used to calculate the 4F 3/2? 4I 11/2 stimulated emission cross section and the 4F 3/2 radiative lifetime. Cross sections showed only a small variation with glass composition, ranging from 2.2 to 3.4 pm 2; the radiative lifetimes ranged from 470 to 650 ?s. Results for these flouride glasses are compared with values for BeF 2-based glasses and for oxide and oxyflouride laser glasses.

  3. Fluorescence properties and electron paramagnetic resonance studies of γ-irradiated Sm3+-doped oxyfluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Babu, B. Hari; Ravi Kanth Kumar, V. V.

    2012-11-01

    The permanent photoinduced valence manipulation of samarium doped oxyfluoroborate glasses as a function of γ-ray irradiation has been investigated using a steady-state fluorescence and electron paramagnetic resonance techniques. An increase in SrF2 content in the glass led to the red shift of the peaks in as prepared glass, while in irradiated glasses this led to the decrease in defect formation as well as increase in photoreduction of Sm3+ to Sm2+ ion. The energy transfer mechanism of induced permanent photoreduction of Sm3+ to Sm2+ ions in oxyfluoroborate glasses has been discussed. The decay analysis shows exponential behavior before irradiation and non-exponential behavior after irradiation. The energy transfer in irradiated glasses increases with the increase in SrF2 content in the glass and also with the irradiation dose.

  4. Properties and structure of high erbium doped phosphate glass for short optical fibers amplifiers

    SciTech Connect

    Seneschal, Karine; Smektala, Frederic . E-mail: Frederic.Smektala@univ-rennes1.fr; Bureau, Bruno; Floch, Marie Le; Jiang Shibin; Luo, Tao; Lucas, Jacques; Peyghambarian, Nasser

    2005-09-01

    New phosphate glasses have been developed in order to incorporate high rare-earth ions concentrations. These glasses present a great chemical stability and a high optical quality. The phosphate glass network is open, very flexible, with a linkage of the tetrahedrons very disordered and contains a larger number of non-bridging oxygens (66%). The great stability and resistance against crystallization associated with the possibility to incorporate high doping concentration of rare-earth ions in these phosphate glasses make them very good candidates for the realization of ultra short single mode amplifiers with a high gain at 1.55 {mu}m.

  5. Structure and distortion of lead fluoride nanocrystals in rare earth doped oxyfluoride glass ceramics.

    PubMed

    Ge, Jin; Zhao, Lijuan; Guo, Hui; Lan, Zijian; Chang, Lifen; Li, Yiming; Yu, Hua

    2013-10-28

    A series of rare earth (RE) doped oxyfluoride glasses with the composition of (45-x) SiO2-5Al2O3-40PbF2-10CdF2-xRe2O3 (x = 1, 5, 10, 15) (mol%) were prepared by a traditional melt-quenching method. Glass ceramics (GCs) were obtained after thermal treatment and characterized by X-ray diffraction (XRD) to investigate the nanocrystal structure and distortion. Both the dopant type and the doping level play an important role in the distortion of the PbF2-RE lattice. It is found that a cubic Pb3REF9 phase forms in low doping GCs, a tetragonal PbREF5 phase forms in middle doping GCs and cubic PbRE3F11 forms in high doping GCs. Accordingly, the site symmetry of RE(3+) dopants in ?-PbF2 nanocrystal undergoes a transition of OhD4hOh with the increase of doping level. The change in the ligands coordinating the RE(3+) ions was further illustrated by the optical changes in Yb-doped GCs. This paper provides insights on the nanocrystal structure of RE at the atomic level and tries to make a complete description of the nanocrystal structure and distortion in these glass-ceramic materials, which will benefit the optimization of optical properties. PMID:24019159

  6. Intense red photoluminescence from Mn2+-doped (Na+; Zn2+) sulfophosphate glasses and glass ceramics as LED converters.

    PubMed

    Da, Ning; Peng, Mingying; Krolikowski, Sebastian; Wondraczek, Lothar

    2010-02-01

    We report on intense red fluorescence from Mn(2+)-doped sulfophosphate glasses and glass ceramics of the type ZnO-Na(2)O-SO(3)-P(2)O(5). As a hypothesis, controlled internal crystallization of as-melted glasses is achieved on the basis of thermally-induced bimodal separation of an SO(3)-rich phase. Crystal formation is then confined to the relict structure of phase separation. The whole synthesis procedure is performed in air at glasses, increasing MnO content results in decreasing network polymerization. Stable glasses and continuously increasing emission intensity are observed for relatively high dopant concentration of up to 3 mol.%. Recrystallization of the glass results in strongly increasing emission intensity. Dynamic emission spectroscopy reveals only on type of emission centers in the glassy material, whereas three different centers are observed in the glass ceramic. These are attributed to octahedrally coordinated Mn(2+) in the residual glass phase and in crystalline phosphate and sulfate lattices, respectively. Relatively low crystal field strength results in almost ideal red emission, peaking around 625 nm. Excitation bands lie in the blue-to-green spectral range and exhibit strong overlap. The optimum excitation range matches the emission properties of GaN- and InGaN-based light emitting devices. PMID:20174083

  7. Determining the 6Li doped side of a glass scintillator for ultra cold neutrons

    NASA Astrophysics Data System (ADS)

    Jamieson, Blair; Rebenitsch, Lori Ann

    2015-08-01

    Ultracold neutron (UCN) detectors using two visually very similar, to the microscopic level, pieces of optically contacted cerium doped lithium glasses have been proposed for high rate UCN experiments. The chief difference between the two glass scintillators is that one side is 6Li depleted and the other side 6Li doped. This note outlines a method to determine which side of the glass stack is doped with 6Li using AmBe and 252Cf neutron sources, and a Si surface barrier detector. The method sees an excess of events around the ? and triton energies of neutron capture on 6Li when the enriched side is facing the Si surface barrier detector.

  8. Application to Temperature Sensor Based on Green Up-Conversion of Er3+ Doped Silicate Glass

    PubMed Central

    Li, Chengren; Dong, Bin; Ming, Chengguo; Lei, Mingkai

    2007-01-01

    The green up-conversion emissions centered at the wavelengths of about 534nm and 549nm of the Er3+ doped silicate glass were recorded, using a 978 nm semiconductor laser diode (LD) as an excitation source. The fluorescence intensity ratio (FIR) of the green up-conversion emissions at about 534nm and 549nm in the Er3+ doped silicate glass was studied as a function of temperature over the temperature range of 296K-673K. The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0023K-1 and 0.8K, respectively. It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+ doped silicate glass could play a major role in temperature measurement.

  9. Ytterbium-doped silica photonic crystal fiber laser fabricated by the nanoporous glass sintering technique

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Wang, Meng; Zhou, Qinling; Feng, Suya; Yu, Chunlei; Wang, Longfei; Hu, Lili; Chen, Danping

    2014-06-01

    Based on the sintering of ytterbium-doped nanoporous glass, a nonchemical vapor deposition process aimed at fabricating a large-mode area of photonic crystal fibers has been proposed for the preparation of active silica glass. With the relatively low doping concentration and boron in the silica glass as benefits, a close refractive index between the core and the cladding was obtained. The refractive index variation indicated good homogeneity of the doped fiber core. Up to 34.8?W laser output was demonstrated with the PCF laser and the slope efficiency was 71.3%. The output laser beam quality had slightly multimode behavior, with a mean M2 of 2.42.

  10. Photoluminescence properties of singly doped Tm3+ and co-doped Tm3+/Tb3+ ions in tellurite glasses

    NASA Astrophysics Data System (ADS)

    Sasikala, T.; Rama Moorthy, L.

    2014-11-01

    Photoluminescence properties of singly doped Tm3+ and co-doped Tm3+/Tb3+ ions in TZKC glasses with chemical composition of (61.5-x) TeO2 + 25 ZnO + 8 K2O + 5CaO + 0.5Tm2O3 + xTb4O7 (TZKCTm05Tbx; x (in mol%) = 0, 0.5, 1.0, 1.5) have been studied. The experimental oscillator strengths of absorption bands in TZKCTm05 glass were used to determine the host dependent Judd-Ofelt ?2, ?4, ?6 intensity parameters. The effective emission cross-section of 1.8 ?m emission band as a function of wavelength has been deduced by the McCumber's theory. Based on the absorption (?a) and emission cross-sections (?e), the gain co-efficients (G) of 1.8 ?m emission band for various population inversions between the emitting (3F4) and terminating (3H6) levels were evaluated. From the photoluminescence spectra of singly doped Tm3+ and co-doped Tm3+/Tb3+ ions in TZKC glasses, the chromaticity color coordinates (x, y) were estimated.

  11. Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium

    SciTech Connect

    PaBlick, C.; Müller, O.; Lützenkirchen-Hecht, D.; Frahm, R.; Johnson, J.A.; Schweizer, S.

    2012-10-10

    The structure/property relationships of fluorochlorozirconate glass ceramics as a function of divalent and trivalent europium (Eu) co-doping and thermal processing have been investigated; the influence of doping ratio on the formation of barium chloride (BaCl2) nanocrystals therein was elucidated. X-ray absorption near-edge structure spectroscopy shows that the post-thermal annealing changes the Eu valence of the as-poured glass slightly, but during the melting process Eu3+ is more strongly reduced to Eu2+, in particular, when doped as a chloride instead of fluoride compound. The Eu2+-to-Eu3+ doping ratio also plays a significant role in chemical equilibrium in the melt. X-ray diffraction measurements indicate that a higher Eu2+ fraction leads to a BaCl2 phase transition from hexagonal to orthorhombic structure at a lower temperature.

  12. Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium

    SciTech Connect

    Passlick, C.; Mueller, O.; Luetzenkirchen-Hecht, D.; Frahm, R.; Johnson, J. A.; Schweizer, S.

    2011-12-01

    The structure/property relationships of fluorochlorozirconate glass ceramics as a function of divalent and trivalent europium (Eu) co-doping and thermal processing have been investigated; the influence of doping ratio on the formation of barium chloride (BaCl{sub 2}) nanocrystals therein was elucidated. X-ray absorption near-edge structure spectroscopy shows that the post-thermal annealing changes the Eu valence of the as-poured glass slightly, but during the melting process Eu{sup 3+} is more strongly reduced to Eu{sup 2+}, in particular, when doped as a chloride instead of fluoride compound. The Eu{sup 2+}-to-Eu{sup 3+} doping ratio also plays a significant role in chemical equilibrium in the melt. X-ray diffraction measurements indicate that a higher Eu{sup 2+} fraction leads to a BaCl{sub 2} phase transition from hexagonal to orthorhombic structure at a lower temperature.

  13. Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium

    PubMed Central

    Palick, C.; Mller, O.; Ltzenkirchen-Hecht, D.; Frahm, R.; Johnson, J. A.; Schweizer, S.

    2011-01-01

    The structure/property relationships of fluorochlorozirconate glass ceramics as a function of divalent and trivalent europium (Eu) co-doping and thermal processing have been investigated; the influence of doping ratio on the formation of barium chloride (BaCl2) nanocrystals therein was elucidated. X-ray absorption near-edge structure spectroscopy shows that the post-thermal annealing changes the Eu valence of the as-poured glass slightly, but during the melting process Eu3+ is more strongly reduced to Eu2+, in particular, when doped as a chloride instead of fluoride compound. The Eu2+-to-Eu3+ doping ratio also plays a significant role in chemical equilibrium in the melt. X-ray diffraction measurements indicate that a higher Eu2+ fraction leads to a BaCl2 phase transition from hexagonal to orthorhombic structure at a lower temperature. PMID:22275772

  14. Spectroscopic properties of Tm3+/Al3+ co-doped sol-gel silica glass

    NASA Astrophysics Data System (ADS)

    Wang, Xue; Lou, Fengguang; Wang, Shikai; Yu, Chunlei; Chen, Danping; Hu, Lili

    2015-04-01

    Tm3+/Al3+ co-doped silica glass was prepared by sol-gel method combined with high temperature sintering. Glasses with compositions of xTm2O3-15xAl2O3-(100 - 16x) SiO2 (in mol%, x = 0.1, 0.3, 0.5, 0.8 and 1.0) were prepared. The high thulium doped silica glass was realized. Their spectroscopic parameters were calculated and analyzed by Judd-Ofelt theory. Large absorption cross section (4.65 10-21 cm2 at 1668 nm) and stimulated emission cross section (6.00 10-21 cm2 at 1812 nm), as well as low hydroxyl content (0.180 cm-1), long fluorescence lifetime (834 ?s at 1800 nm), large ?em ?rad (30.05 10-21 cm2 ms) and large relative intensity ratio of the 1.8 ?m (3F4 ? 3H6) to 1.46 (3H4 ? 3F4) emissions (90.33) are achieved in this Tm3+/Al3+ co-doped silica glasses. According to emission characteristics, the optimum thulium doping concentration is around 0.8 mol%. The cross relaxation (CR) between ground and excited states of Tm3+ ions was used to explain the optimum thulium doping concentration. These results suggest that the sol-gel method is an effective way to prepare Tm3+ doped silica glass with high Tm3+ doping and prospective spectroscopic properties.

  15. Line patterning of (Sr,Ba)Nb{sub 2}O{sub 6} crystals in borate glasses by transition metal atom heat processing

    SciTech Connect

    Sato, M.; Honma, T.; Benino, Y.; Komatsu, T.

    2007-09-15

    Some NiO-doped Bi{sub 2}O{sub 3},La{sub 2}O{sub 3}-SrO-BaO-Nb{sub 2}O{sub 5}-B{sub 2}O{sub 3} glasses giving the formation of strontium barium niobate Sr{sub 0.5}Ba{sub 0.5}Nb{sub 2}O{sub 6} (SBN) crystals with a tetragonal tungsten-bronze structure through conventional crystallization in an electric furnace have been developed, and SBN crystal lines have been patterned on the glass surface by heat-assisted (250-300 deg. C) laser irradiation and scanning of continuous-wave Nd:YAG laser (wavelength: 1064 nm). The surface morphology and the quality of SBN crystal lines are examined from measurements of confocal scanning laser micrographs and polarized micro-Raman scattering spectra. The surface morphology of SBN crystal lines changes from periodic bump structures to homogeneous structures, depending on laser scanning conditions. It is suggested that the line patterned at the laser irradiation condition of laser power P=1 W and of laser scanning speed S=1 {mu}m/s in 2NiO-4La{sub 2}O{sub 3}-16SrO-16BaO-32Nb{sub 2}O{sub 5}-30B{sub 2}O{sub 3} glass has a possibility of the orientation of SBN crystals along the laser scanning direction. The present study demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass. - Graphical abstract: This figure shows the polarization optical (a) and confocal scanning laser (b) micrographs for the sample obtained by heat-assisted (300 deg. C) Nd:YAG laser irradiation with a laser power of P=1 W and laser scanning speed of S=1 {mu}m/s in Glass C. The figure demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass.

  16. Spatial and temporal observation of energy transfer processes in Pr-doped phosphate glasses

    NASA Astrophysics Data System (ADS)

    Martins, V. M.; Azevedo, G. A.; Andrade, A. A.; Messias, D. N.; do Monte, A. F. G.; Dantas, N. O.; Pilla, V.; Catunda, T.; Braud, A.; Moncorg, R.

    2014-11-01

    A spatially resolved microluminescence technique was used to measure the spatial distribution of emitted light and photon propagation into two different Pr3+ doped phosphate glasses. The photon diffusion length for specific wavelengths was measured. It was found that excited state re-absorption plays a crucial role in the propagation. Our results suggest that this microluminescence technique can be applied in the investigation of energy transfer processes in rare-earth doped systems.

  17. Tm3+ doped Ga-As-S chalcogenide glasses and fibers

    NASA Astrophysics Data System (ADS)

    Galstyan, A.; Messaddeq, S. H.; Fortin, V.; Skripachev, I.; Valle, R.; Galstian, T.; Messaddeq, Y.

    2015-09-01

    Tm3+ doped Ga-As-S chalcogenide glass samples were produced using As2S3 pure glass as starting materials. Their photoluminescence properties were characterized and strong emission bands were observed at 1.2 ?m (1H5 ? 3H6), 1.4 ?m (3H4 ? 3F4) and 1.8 ?m (3F4 ? 3H6) under excitation wavelengths of 698 nm and 800 nm. The thulium and gallium concentrations were optimized to achieve the highest photoluminescence efficiency. From the optimal composition, a Tm3+ doped Ga-As-S fiber was drawn and its optical properties were studied.

  18. Broadband infrared luminescence in Yb-doped Bi2O3-GeO2 glasses

    NASA Astrophysics Data System (ADS)

    Yu, Pingsheng; Su, Liangbi; Cheng, Junhua; Xu, Jun

    2016-01-01

    The Yb-doped Bi2O3-GeO2 glasses were prepared by the conventional melt quenching technique. Near-infrared (NIR) broadband emission was found at about 1024 nm, and 1330 nm (under 785 nm excitation), and the measured fluorescent lifetime was about several hundred microseconds. The emission intensity of Yb-doped Bi2O3-GeO2 glasses increased with increasing of Yb dopant in our experiments. The NIR emission should be related to Yb3+ and lower valence Bi ions.

  19. Cerium and boron chemistry in doped borosilicate glasses examined by EELS.

    PubMed

    Yang, G; Mbus, G; Hand, R J

    2006-01-01

    Spatially resolved measurements of boron coordination and cerium valency in a doped borosilicate glass with crystalline nano-precipitates are described. The fine structure of the boron K-edge and the white-line ratio of the cerium M-edge doublet were evaluated from EELS line scans. Due to high beam sensitivity it was found that reliable boron-coordination measurements in some of the glasses studied required extrapolation of results acquired after different periods of irradiation back to a zero-irradiation. However, borosilicates that contained heavy alkali atoms were found to suffer very little structural change. The Ce valency of a 4% (molar) doped alkali-borosilicate glass was found to be mixed +III/+IV in the glass matrix and purely +IV (indicative of CeO2) in the precipitates. A significant dependency of the valence results on the data processing method was found and explained. PMID:16481178

  20. Laser irradiation in Nd{sup 3+} doped strontium barium niobate glass

    SciTech Connect

    Haro-Gonzalez, P.; Martin, I. R.; Arbelo-Jorge, E.; Gonzalez-Perez, S.; Caceres, J. M.; Nunez, P.

    2008-07-01

    A local nanocrystalline formation in a neodymium doped strontium barium niobate (SBN) glass has been obtained under argon laser irradiation. The intense emission around 880 nm, originated from the {sup 4}F{sub 3/2} ({sup 4}F{sub 5/2}) thermalized level when the glass structure changes to a glass ceramic structure due to the irradiation of the laser beam, has been studied. The intensities and lifetimes change from this level inside and outside the irradiated area made by the laser excitation. They have been analyzed and demonstrated that the desvitrification process has been successfully achieved. These results confirm that nanocrystals of SBN have been created by the laser action confirming that the transition from glass to glass ceramic has been completed. These results are in agreement with the emission properties of nanocrystals of the bulk glass ceramic sample. The present study also suggests that the SBN nanocrystal has a potential application as temperature detector.

  1. Preparation and optical properties of Bi2S3-microcrystallite-doped glass and thin film

    NASA Astrophysics Data System (ADS)

    Jiang, Zhonghong; Ye, Hui

    1994-10-01

    The Bi2S3 microcrystallite doped thin films and glass lumps have been successfully prepared by the sol-gel process, the size of the microcrystallite in glass heated for different times at 400 degree(s)C was decided by the method of HRTEM. The optical transmission valley shifted towards longer wavelengths with longer heat-treatment time at 500 degree(s)C in the Bi2S3 doped thin films, showing the experimental evidence of quantum size effects. The red-shift of emission peaks in luminescence spectrum excited with longer wavelength is attributed to the broad distribution of particle size in Bi2S3 doped glass. The nonlinear refractive index of the Bi2S3 quantum dots glass which is studied by the method of Z- scan gives n2 equals 3.3089 X 10-9 esu. The optical second generation (SHG) of the Bi2S3-doped glass also is observed using a Nd:YAG colliding mode locked laser.

  2. Lasers based on dye-doped sol-gel composite glasses

    NASA Astrophysics Data System (ADS)

    Rahn, Mark D.; King, Terence A.

    1994-10-01

    Higher energy laser action in partially densified sol-gel glass, sol-gel glass composites and polymethylmethacrylate (PMMA) doped with laser dyes is reported. Post-doping, in which the active dye is diffused into the densified porous sol-gel matrix, has been developed into an effective method for the impregnation of organic species. The sol-gel glass composite is formed by refractive index matching the porous sol-gel glass by impregnation with polymethylmethacrylate. This is achieved by in-situ polymerization of methylmethacrylate. This reduced optical attenuation from 0.7 dB/cm to 0.4 dB/cm. By formation of the composite the chemical environment of some dyes is improved. Laser performance is described for the dyes rhodamine 590, pyrromethene 567, and the perylene derivatives perylene orange (KF 241) and perylene red (KF 856), in the three solid state hosts when pumped with the second harmonic of a Nd:YAG laser. As a comparison, their performance is also described in solution. For laser performance, the best combinations of dye and host in terms of both efficiency and photostability were found to be rhodamine 590 in sol-gel glass and perylene orange in sol-gel glass/PMMA composite. Long pulse lasing has also been demonstrated with rhodamine 590 in sol-gel glass and sol-gel glass/PMMA composite and pyrromethene 567 in sol-gel glass, using a flashlamp pumped coumarin 504 dye laser as a pump source, emitting 3 microsecond(s) pulses at 504 nm. We also give the first report on de-oxygenated pyrromethene 567 doped sol-gel glass/PMMA composites. De-oxygenation improved the photostability of this dye in the composite by a factor of four.

  3. Comparative investigation on the spectroscopic properties of Pr?-doped boro-phosphate, boro-germo-silicate and tellurite glasses.

    PubMed

    Zhang, Liaolin; Dong, Guoping; Peng, Mingying; Qiu, Jianrong

    2012-07-01

    We report on the spectroscopic properties of Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses. The stimulated absorption and emission cross sections were estimated. Only one emission at 596 nm and 605 nm is observed in Pr(3+)-doped boro-phosphate and boro-germo-silicate glasses, respectively, while three emissions at 605 nm, 612 nm and 645 nm are observed in Pr(3+)-doped tellurite glass when excited at 467 nm. The fluorescence lifetime at 600 nm in Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses is 137 ?s, 73 ?s and 51 ?s, respectively. The emissions from Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses show different decay behaviors and can be well explained by multiphonon relaxation theory. PMID:22484255

  4. Highly efficient reddish orange emission in Mn2+/Eu3+ co-doped phosphate glasses for greenhouse

    NASA Astrophysics Data System (ADS)

    Ming, Chengguo; Song, Feng; Ren, Xiaobin; An, Liqun

    2013-07-01

    A series of phosphate glasses doped with Mn2+/Eu3+ ions were prepared by high temperature melting method to explore reddish orange luminescent materials for greenhouse. The absorption, emission, and excitation spectra of the samples were studied in detail. A wide excitation band at 300-550 nm in the Mn2+/Eu3+ co-doped phosphate glasses was observed. Under the illumination of sunlight, the Mn2+/Eu3+ co-doped phosphate glasses can emit strong red emission. Our materials will be helpful to improve the utilization of solar for glass greenhouses.

  5. Synthesis and optical properties of CsC1-doped gallium-sodium-sulfide glasses

    SciTech Connect

    Hehlen, Markus P; Bennett, Bryan L; Williams, Darrick J; Muenchausen, Ross E; Castro, Alonso; Tornga, Stephanie C

    2009-01-01

    Ga{sub 2}S{sub 3}-Na{sub 2}S (GNS) glasses doped with CsCl were synthesized in open crucibles under inert atmosphere. The evaporative loss of CsCl during glass melting was measured by energy dispersive X-ray spectroscopy and corrected for by biasing the CsCl concentration in the mixture of starting materials to obtain glasses with accurately controlled stoichiometry. Glass transition temperatures, refractive index dispersions, and band edge energies were measured for four GNS:CsCl glasses, and the respective values were found to significantly improve over earlier studies that did not mitigate CsCl evaporative losses. The refractive index dispersion measurements indicate that the Cs{sup +} and Cl{sup -} radii are 16% larger in GNS:CsCl glass than in bulk crystalline CsCl. The band edge energy increases from 2.97 eV in GNS glass to 3.32 eV in GNS glass doped with 20 mol% CsCl as a result of introducing Cl{sup -} ions having a large optical electronegativity. The large bandgap of 3.32 eV and the low (450 cm{sup -1}) phonon energy make GNS:20%CsCl an attractive host material for rare-earth ions with radiative transitions in the near ultra-violet, visible, and near-infrared spectral regions.

  6. Spectroscopic properties and energy transfer parameters of Er3+- doped fluorozirconate and oxyfluoroaluminate glasses

    NASA Astrophysics Data System (ADS)

    Huang, Feifei; Liu, Xueqiang; Hu, Lili; Chen, Danping

    2014-05-01

    Er3+- doped fluorozirconate (ZrF4-BaF2-YF3-AlF3) and oxyfluoroaluminate glasses are successfully prepared here. These glasses exhibit significant superiority compared with traditional fluorozirconate glass (ZrF4-BaF2-LaF3-AlF3-NaF) because of their higher temperature of glass transition and better resistance to water corrosion. Judd-Ofelt (J-O) intensity parameters are evaluated and used to compute the radiative properties based on the VIS-NIR absorption spectra. Broad emission bands located at 1535 and 2708 nm are observed, and large calculated emission sections are obtained. The intensity of 2708 nm emission closely relates to the phonon energy of host glass. A lower phonon energy leads to a more intensive 2708 nm emission. The energy transfer processes of Er3+ ions are discussed and lifetime of Er3+: 4I13/2 is measured. It is the first time to observe that a longer lifetime of the 4I13/2 level leads to a less intensive 1535 nm emission, because the lifetime is long enough to generate excited state absorption (ESA) and energy transfer (ET) processes. These results indicate that the novel glasses possess better chemical and thermal properties as well as excellent optical properties compared with ZBLAN glass. These Er3+- doped ZBYA and oxyfluoroaluminate glasses have potential applications as laser materials.

  7. Yb-doped silica glass and photonic crystal fiber based on laser sintering technology

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Wu, Jiale; Zhou, Guiyao; Xia, Changming; Liu, Jiantao; Tian, Hongchun; Liang, Wanting; Hou, Zhiyun

    2016-03-01

    We demonstrate the fabricating method for Yb3+-doped silica glass and double-cladding large mode area photonic crystal fiber (LMA PCF) based on laser sintering technology combined with a liquid phase doping method. The doped material prepared shows the amorphous property and the hydroxyl content is approximately 40 ppm. The attenuation of the fabricated LMA PCF is 14.2 dB m‑1 at 976 nm, and the lowest value is 0.25 dB m‑1 at 1200 nm. The laser slope efficiency is up to 70.2%.

  8. Radiation hardening in sol-gel derived Er3+-doped silica glasses

    NASA Astrophysics Data System (ADS)

    Hari Babu, B.; Ollier, Nadge; Len Pichel, Mnica; El Hamzaoui, Hicham; Poumellec, Bertrand; Bigot, Laurent; Savelii, Inna; Bouazaoui, Mohamed; Ibarra, Angel; Lancry, Matthieu

    2015-09-01

    The aim of the present paper is to report the effect of radiation on the Er3+-doped sol-gel silica glasses. A possible application of these sol-gel glasses could be their use in harsh radiation environments. The sol-gel glasses are fabricated by densification of erbium salt-soaked nanoporous silica xerogels through polymeric sol-gel technique. The radiation-induced attenuation of Er3+-doped sol-gel silica is found to increase with erbium content. Electron paramagnetic resonance studies reveal the presence of E'? point defects. This happens in the sol-gel aluminum-silica glass after an exposure to ?-rays (kGy) and in sol-gel silica glass after an exposure to electrons (MGy). The concentration levels of these point defects are much lower in ?-ray irradiated sol-gel silica glasses. When the samples are co-doped with Al, the exposure to ?-ray radiation causes a possible reduction of the erbium valence from Er3+ to Er2+ ions. This process occurs in association with the formation of aluminum oxygen hole centers and different intrinsic point defects.

  9. Down- and up-conversion emissions in Er-doped transparent fluorotellurite glass-ceramics

    NASA Astrophysics Data System (ADS)

    Miguel, A.; Morea, R.; Gonzalo, J.; Fernandez, J.; Balda, R.

    2015-03-01

    In this work, we report the near infrared and upconversion emissions of Er3+-doped transparent fluorotellurite glassceramics obtained by heat treatment of the precursor Er-doped TeO2-ZnO-ZnF2 glass. Structural analysis shows that ErF3 nanocrystals nucleated in the glass-ceramic sample are homogeneously distributed in the glass matrix with a typical size of 4510 nm. The comparison of the fluorescence properties of Er3+-doped precursor glass and glass-ceramic confirms the successful incorporation of the rare-earth into the nanocrystals. An enhancement of the red upconversion emission due to 4F9/2?4I15/2 transition together with weak emission bands due to transitions from 2H9/2, 4F3/2,5/2, and 4F7/2 levels to the ground state are observed under excitation at 801 nm in the glass-ceramic sample. The temporal evolution of the red emission together with the excitation upconversion spectrum suggest that energy transfer processes are responsible for the enhancement of the red emission.

  10. Cubic to tetragonal phase transition of Tm3+ doped nanocrystals in oxyfluoride glass ceramics

    NASA Astrophysics Data System (ADS)

    Li, Yiming; Zhao, Lijuan; Fu, Yuting; Shi, Yahui; Zhang, Xiaoyu; Yu, Hua

    2016-02-01

    Tm3+ ions doped ?-PbF2 nanocrystals in oxyfluoride glass ceramics with different doping concentrations and thermal temperatures are prepared by a traditional melt-quenching and thermal treatment method to investigate the structure and the phase transition of Tm3+ doped nanocrystals. The structures are characterized by X-ray diffraction Rietveld analysis and confirmed with numerical simulation. The phase transitions are proved further by the emission spectra. Both of the doping concentration and thermal temperature can induce an Oh to D4h site symmetry distortion and a cubic to tetragonal phase transition. The luminescence of Tm3+ doped nanocrystals at 800 nm was modulated by the phase transition of the surrounding crystal field.

  11. In-vitro bioactivity of zirconia doped borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Samudrala, Rajkumar; Azeem, P. Abdul

    2015-06-01

    Glass composition 31B2O3-20SiO2-24.5Na2O-(24.5-x) CaO-xZrO2 x=1,2,3,4,5 were prepared by melt-quenching Technique. The formation of hydroxyapatite layer on the surface of glasses after immersion in simulated body fluid (SBF) was explored through XRD, Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM-EDX) analyses. In this report, we observed that hydroxyapatite formation for 5days of immersion time. Also observed that with increasing the immersion time up to 15days, higher amount of hydroxyapatite layer formation on the surface of glasses. The varying composition of zirconia in glass samples influences shown by XRD, FTIR studies. The present results indicate that, in-vitro bioactivity of glasses decreased with increasing zirconia incorporation.

  12. Hyperpolarized cesium ions doped in a glass material

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kiyoshi

    2014-12-01

    Hyperpolarized (HP) 133 Cs nuclear magnetic resonance signals were measured from borosilicate glass cell walls during optical pumping of cesium vapor at high magnetic field (9.4 T). Significant signal enhancements were observed when additional heating of the cell wall was provided by intense but non-resonant laser irradiation, with integrated HP 133 Cs NMR signals and line widths varying as a function of heating laser power (and hence glass temperature). Given that virtually no Cs ions would originally be present in the glass, absorbed HP Cs atoms rarely met thermally-polarized Cs ions already at the surface; thus, spin-exchange via nuclear dipole interaction cannot be the primary mechanism for injecting spin polarization into the glass. Instead, it is concluded that the absorption and transport of HP atoms into the glass material itself is the dominant mechanism of nuclear spin injection at high temperatures-the first reported experimental demonstration of such a mechanism.

  13. Thermal analysis, spectral characterization and refractive index studies of lithium doped PbO-ZnO-B{sub 2}O{sub 3} glass

    SciTech Connect

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2012-06-05

    Lithium containing lead zinc borate glasseshave been prepared by melt quenching technique. X-ray diffraction reveals the amorphous nature of the glass. Differential scanning calorimeter (DSC) study was carried out in the temperature range RT to 600 deg. C temperature and found glass transition temperature of these glasses decreases with increase in inter substitution of Pb and Zn lithium content. PZB glasses are stable, IR spectra of these glasses show characteristics band originating from borate groups namely [BO{sub 3}] [BO{sub 4}]and B-O-B stretching vibrations respectively, and found that structure is not affected with effect of lithium content. Refractive index of these glasses are in the range of 1.47 with increasing lithium content refractive index decreases indicating decrease in scattering of light.

  14. Properties and Applications of Laser-Induced Gratings in Rare Earth Doped Glasses.

    NASA Astrophysics Data System (ADS)

    Behrens, Edward Grady

    Scope and method of study. Four-wave-mixing techniques were used in an attempt to create permanent laser-induced grating in Pr^{3+}-, Nd ^{3+}-, Eu^ {3+}-, and Er^{3+ }-doped glasses. The permanent laser-induced grating signal intensity and build-up and erase times were investigated as function of the write beam crossing angle, write beam power, and temperature. Thermal lensing measurements were conducted on Eu^{3+} - and Nd^{3+}-doped glasses and room temperature Raman and resonant Raman spectra were obtained for Eu^{3+}-doped glasses. The permanent laser-induced grating signal intensity was studied in Eu^{3+} -doped alkali-metal glasses as a function of the alkali -metal network modifier ion and a model was developed by treating the sample as a two-level system. Optical device applications of the permanent laser-induced gratings were studied by creating some simple devices. Findings and conclusions. Permanent laser-induced gratings were created in the Pr^{3+ }- and Eu^{3+} -doped glasses. The permanent laser-induced grating is associated with a structural phase change of the glass host. The structural change is produced by high energy phonons which are emitted by radiationless relaxation processes of the rare earth ion. Nd^{3+} and Er^{3+} relax nonradiatively by the emission of phonons of much lower energy which are unable to produce the structural phase change needed to form a permanent laser-induced grating. The difference in energy of the emitted phonons is responsible for the differing characteristics of the thermal lensing experiments. The model does a good job of predicting the experimental results for the asymmetry and other parameters of the two-level system. The application of these laser -induced gratings for optical devices demonstrates their importance to optical technology.

  15. Gamma ray interaction with lithium diborate glasses containing transition metals ions

    NASA Astrophysics Data System (ADS)

    El Batal, F. H.; El Kheshen, A. A.; Azooz, M. A.; Abo-Naf, S. M.

    2008-02-01

    UV-visible spectroscopy of undoped and TM-doped (Ti-Cu) lithium diborate glasses have been measured before and after successive gamma irradiation. In the undoped borate glass, strong charge transfer UV bands are observed at 235 and 280 nm which are related mostly to trace iron impurities (Fe 3+) ions. In the TM-doped glasses, characteristics absorption bands are obtained due to each specific TM ion in addition to that due to the base glass. Gamma irradiation produced induced bands due either to the intrinsic host borate glass in the UV region at about 210, 230, 280 nm and one visible band at 540 nm or extrinsic bands which are different according to the added TM ions and initiated by photochemical processes. The rate of induced color centers formation is fast at first and then becomes slower or reaches saturation and some TM ions (V, Cr, Co, Ni, Cu) show retardation or shielding to gamma ray but with varying degrees. Infrared absorption measurements of the undoped and TM-doped glasses are measured to justify the structural groups of the host lithium borate glass and the effects of TM ions on their arrangement. Gamma irradiation causes a decrease in the intensities of the IR bands accompanied by losing sharpness. These features are related to more amorphicity or disorder by irradiation or to the possible changes in bond angle or bond length in the building groups arrangement.

  16. Energy transfer kinetics in oxy-fluoride glass and glass-ceramics doped with rare-earth ions

    SciTech Connect

    Sontakke, Atul D.; Annapurna, K.

    2012-07-01

    An investigation of donor-acceptor energy transfer kinetics in dual rare earths doped precursor oxy-fluoride glass and its glass-ceramics containing NaYF{sub 4} nano-crystals is reported here, using three different donor-acceptor ion combinations such as Nd-Yb, Yb-Dy, and Nd-Dy. The precipitation of NaYF{sub 4} nano-crystals in host glass matrix under controlled post heat treatment of precursor oxy-fluoride glasses has been confirmed from XRD, FESEM, and transmission electron microscope (TEM) analysis. Further, the incorporation of dopant ions inside fluoride nano-crystals has been established through optical absorption and TEM-EDX analysis. The noticed decreasing trend in donor to acceptor energy transfer efficiency from precursor glass to glass-ceramics in all three combinations have been explained based on the structural rearrangements that occurred during the heat treatment process. The reduced coupling phonon energy for the dopant ions due to fluoride environment and its influence on the overall phonon assisted contribution in energy transfer process has been illustrated. Additionally, realization of a correlated distribution of dopant ions causing clustering inside nano-crystals has also been reported.

  17. Effects of rare-earth doping on femtosecond laser waveguide writing in zinc polyphosphate glass

    SciTech Connect

    Fletcher, Luke B.; Witcher, Jon J.; Troy, Neil; Krol, Denise M.; Reis, Signo T.; Brow, Richard K.

    2012-07-15

    We have investigated waveguide writing in Er-Yb doped zinc polyphosphate glass using a femtosecond laser with a repetition rate of 1 KHz. We find that fabrication of good waveguides requires a glass composition with an O/P ratio of 3.25. The dependence on laser writing parameters including laser fluence, focusing conditions, and scan speed is reported. Waveguide properties together with absorption and emission data indicate that these glasses can be used for the fabrication of compact, high gain amplifying devices.

  18. Decay kinetics and energy transfer in ternary phosphate glass doped Eu and Eu/Dy

    NASA Astrophysics Data System (ADS)

    Polisadova, E. F.; Othman, H. A.

    2016-02-01

    Different series of glass samples with different glass compositions and different concentrations of rare earth ions (Eu and Eu/ Dy co-doped) were prepared. Excitation and photoluminescence spectra were measured, for which the observed peaks are attributed to the f-f transitions of the rare earth ions. Decay kinetics of the characteristic emission peaks were registered and investigated using Inokuti-Hirayama model (IH model),when the emission decay deviated from the exponential pattern to study energy transfer in the prepared samples. The IH model is used to determine the energy transfer parameter which is correlated to the glass composition factor.

  19. Preparation and photoluminescence of monolithic silica glass doped with Tb3+ ions using SiO2-PVA nanocomposite

    NASA Astrophysics Data System (ADS)

    Ikeda, Hiroshi; Murata, Takahiro; Fujino, Shigeru

    2014-05-01

    The monolithic silica glass doped with Tb3+ ions was fabricated using the SiO2-PVA nanocomposite as the glass precursor. In order to dope Tb3+ ions in the monolithic silica glass, the mesoporous SiO2-PVA nanocomposite was immersed in the Tb3+ ions contained solution and subsequently sintered at 1100 C in air. Consequently the monolithic transparent silica glass was obtained, exhibiting green fluorescence attributed to 5D4 ? 7F5 main transitions under UV excitation. The Tb concentration in the sintered glass could be controlled by immersion time of the nanocomposite in the solution.

  20. 2 ?m Emission of Ho 3+-doped fluorophosphate glass sensitized by Yb 3+

    NASA Astrophysics Data System (ADS)

    Tian, Ying; Zhang, Liyan; Feng, Suya; Xu, Rongrong; Hu, Lili; Zhang, Junjie

    2010-09-01

    Two micrometer emission of Ho 3+-doped new fluorophosphate glass sensitized by Yb 3+ upon excitation of a conventional 980 nm laser diode is reported. Based on the measured absorption spectra, the Judd-Ofelt parameters and radiative properties were calculated and discussed. For Yb 3+/Ho 3+ codoped fluorophosphate glass, the predicted spontaneous transition probability and emission cross-section of Ho 3+: 5I 7? 5I 8 reaches 73.54 s -1 and 4.66 10 -21 cm 2 , respectively, are much higher than other reported glasses. Larger product of emission cross-section ( ? em) and radiative lifetime ( ? rad) in the prepared glass shows the prepared glass is expected to be better laser material. In addition, the ? em and maximum gain coefficient of Ho 3+ in Yb 3+/Ho 3+ codoped fluorophosphate glass is 12.02% and 12.12% larger than those of Ho 3+ singly-doped sample, respectively. The results suggest Yb 3+/Ho 3+ fluorophosphate glass is a good candidate for efficient 2 ?m laser.

  1. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

    PubMed

    Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

    2016-01-01

    Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. PMID:26478303

  2. Upconversion properties of Er3+-doped oxyfluoride glass-ceramics containing SrF2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Kesavulu, C. R.; Kiran Kumar, K.; Jayasankar, C. K.

    2014-03-01

    Er3+-doped oxyfluoride glass and glass-ceramics containing SrF2 nanocrystals have been prepared and investigated their spectroscopic and luminescence properties. The formation of SrF2 nanocrystals in glass-ceramics were confirmed by Xray diffraction (XRD) and transmission electron microscopy (TEM). Judd-Ofelt parameters have been evaluated from absorption spectra of the Er3+-doped glass, which in turn used to predict radiative properties for the fluorescent levels of Er3+ ions. The intensities of both Stokes and upconversion (anti-Stokes) emissions significantly increase with increase of the size of the fluoride crystals in the glass matrix. The mechanism of green and red upconversion emissions have been ascribed to two photon processes. The lifetime of the 4S3/2 level of the Er3+ ions in glass-ceramics is found to be slightly higher than that of the counter glass, which may be due to the incorporation of Er3+ ions into the low phonon sites of SrF2 nanocrystals.

  3. Er{sup 3+}-doped soda-lime glasses and planar waveguide devices

    SciTech Connect

    Bruce, A.J.; Grodkiewicz, W.H.; Shmulovich, J.

    1996-12-31

    The fabrication and optical performance of planar optical waveguide amplifiers, comprising of deposited Er{sup 3+}-doped soda-lime glass cores on silicon optical bench platforms is documented in this paper. The results are encouraging for practical device applications. A laser device has also been characterized. Its modest performance highlights some of the differences between amplifiers and lasers.

  4. Phase-resolved photoacoustic spectroscopy: Application to metallic-ion-doped glasses

    NASA Astrophysics Data System (ADS)

    Lima, G. A. R.; Baesso, M. L.; Arguello, Z. P.; da Silva, E. C.; Vargas, H.; Miranda, L. C. M.

    1987-12-01

    The possibility of using the phase shift of the photoacoustic signal of different constituents of a composite sample for resolving the spectra of the constituents, at a fixed modulation frequency, is discussed. The proposed method is experimentally tested using samples of soda-lime-silica glass doped with binary oxide mixtures.

  5. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    NASA Astrophysics Data System (ADS)

    Vasileva, A. A.; Nazarov, I. A.; Olshin, P. K.; Povolotskiy, A. V.; Sokolov, I. A.; Manshina, A. A.

    2015-10-01

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium-phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass.

  6. Thermal, optical and structural properties of Dy3+ doped sodium aluminophosphate glasses

    NASA Astrophysics Data System (ADS)

    Kaur, Manpreet; Singh, Anupinder; Thakur, Vanita; Singh, Lakhwant

    2016-03-01

    Trivalent Dysprosium doped sodium aluminophosphate glasses with composition 50P2O5-10Al2O3-(20-x)Na2O-20CaO-xDy2O3 (x varying from 0 to 5 mol%) were prepared by melt quench technique. The density of the prepared samples was measured using Archimedes principle and various physical properties like molar volume, rare earth ion concentration, polaron radius, inter nuclear distance and field strength were calculated using different formulae. The differential scanning calorimetry (DSC) was carried out to study the thermal stability of prepared glasses. The UV Visible absorption spectra of the dysprosium doped glasses were found to be comprised of ten absorption bands which correspond to transitions from ground state 6H15/2 to various excited states. The indirect optical band gap energy of the samples was calculated by Tauc's plot and the optical energy was found to be attenuated with Dy3+ ions. The photoluminescence spectrum revealed that Dy3+ doped aluminophosphate glasses have strong emission bands in the visible region. A blue emission band centred at 486 nm, a bright yellow band centred at 575 nm and a weak red band centred at 668 nm were observed in the emission spectrum due to excitation at 352 nm wavelength. Both FTIR and Raman spectra assert slight structural changes induced in the host glass network with Dy3+ ions.

  7. Structural studies of lithium boro tellurite glasses doped with praseodymium and samarium oxides

    SciTech Connect

    Damas, Pedro; Coelho, Joo; Hungerford, Graham; Hussain, N. Sooraj

    2012-11-15

    Graphical abstract: [TeO{sub 4}] trigonal bipyramid structural unit, which is formed by two unequivalent pair of oxygen atoms: two equatorial oxygens (O{sub eq}) and two axial oxygens (O{sub ax}). Highlights: ? Pr{sup 3+} and Sm{sup 3+} doped LBT glasses have been prepared and characterized. ? LBT glasses present normal surfaces without metallic clusters. ? Raman spectra revealed the network modifying behaviour of dopant ions. -- Abstract: This paper reports the preparation and structural studies of praseodymium and samarium (0.5, 2 and 4 mol%) oxide doped lithium boro tellurite glasses. These materials were prepared by the quenching technique in a ceramic crucible at 950 C. Structural characterization was performed by Raman spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopy techniques. Results from Raman analysis are in good agreement with those reported in the literature, revealing a normal glass structure for the host material. Understanding on how the glasses internal structure changed when the doping concentration increases was also assessed.

  8. Development of bismuth doped lead-aluminum-zinc-germanate glass as a broadband optical gain medium

    NASA Astrophysics Data System (ADS)

    Hughes, M.; Suzuki, T.; Ohishi, Y.

    2009-02-01

    In this paper we present the development process of a glass based on bismuth and aluminum co-doped germanate (GAB) glass. Other workers have demonstrated broadband optical gain in GAB glass. We found the addition of PbO to this glass (GAPB glass) increased the quantum efficiency (QE). Excitation of GAPB glass at 808 nm produced emission peaking at 1230 nm with a width of 260 nm, indicating the glass may be useful as a broadband optical amplifier covering the second telecoms window. The composition of each component of the GAPB glass was optimized for the QE and lifetime of this emission to produce an optimized composition of 87.4GeO2-6Al2O3-6PbO-0.6Bi2O3 (% molar) which had a QE of 67%. However, this composition contained many white inclusions which x-ray diffraction measurements indicated were a phase separation. This would make the glass unsuitable for fibre fabrication. We tried a variety of melting condition which did not improve the glass, the melting conditions did however affect the QE and lifetime. The optimum melting conditions were 1250C for 30 min in a N2 atmosphere. Next we tried adding various quantities of a variety of glass additives including SiO2, LiO, ZnO and SrCO3. All these additives reduced the QE, and all except SiO2 produced a transparent glass in the appropriate quantity. The quantity of these additives which gave a transparent glass and their QE's were LiO: 10% and 6%, ZnO: 10% and 43%, SrCO3: 5% and 27% respectively. Therefore the optimized composition for QE and transparency is 74.4GeO2-10ZnO-6Al2O3-6PbO-0.6Bi2O3.

  9. Bioactive glass in tissue engineering

    PubMed Central

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  10. Bioactive glass in tissue engineering.

    PubMed

    Rahaman, Mohamed N; Day, Delbert E; Bal, B Sonny; Fu, Qiang; Jung, Steven B; Bonewald, Lynda F; Tomsia, Antoni P

    2011-06-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  11. Structural and optical properties of erbium-doped willemite-based glass-ceramics.

    PubMed

    Sarrigani, G V; Matori, K A; Lim, W F; Kharazmi, A; Quah, H J; Bahari, H R; Hashim, M

    2015-11-20

    Willemite-based glass-ceramic was prepared from waste material using a conventional melt and quenching method. The crystalline willemite-based glass-ceramic was doped with Er2O3 (1-5 wt.%) followed by sintering at different temperatures (500°C-1100°C). Density and linear shrinkage were increased with the increase of the sintering temperature. Ultraviolet-visible spectroscopy (UV-Vis) confirmed an optimum optical absorption for sample doped with 3 wt.% of Er2O3 and sintered at 900°C. Photoluminescence measurements further confirmed 3 wt.% of Er2O3 as the optimum percentage of dopant. Results suggested that the obtained glass-ceramic could be a promising material for use as fiber amplifiers. PMID:26836559

  12. Tunable mid-infrared luminescence from Er3+ -doped germanate glass.

    PubMed

    Li, Bingpeng; Wei, Tao; Tian, Ying; Jing, Xufeng; Chen, Fangze; Wang, Fengchao; Zhang, Junjie; Cai, Muzhi; Xu, Shiqing

    2015-09-01

    Er(3+) -doped germanate glasses with superior thermal stability were prepared. Judd-Ofelt intensity parameters and important spectroscopic properties were discussed in detail. Upon 800 nm and 980 nm LD pumping, 2.7 m fluorescence characteristics were investigated and it was found that the effective 2.7 m emission bandwidth can reach to 101.79 nm in prepared glasses. The tunability of the 2.7 m emission band can be realized by adjusting the Er(3+) content. Moreover, a high-emission cross-section (11.09 10(-21) cm(2) ), large gain bandwidth (772.30 10(-28) cm(3) ) and gain coefficient (6.72 cm(-1) ) were obtained in the prepared sample. Hence, Er(3+) -doped germanate glass might be a promising mid-infrared material for tunable amplifiers or lasers. PMID:25408330

  13. Fluorescence enhancement of Er3 + -doped sol-gel glass by aluminum codoping

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Lam, Y. L.; Wang, S. S.; Liu, H. L.; Kam, C. H.; Chan, Y. C.

    1997-08-01

    Erbium-doped silica glasses prepared by the sol-gel process are desirable for applications in high-power lasers and integrated optical devices. However, its fluorescence could be quenched due to the high hydroxyl (OH-) content. Although this OH- content can be greatly reduced through special gas treatment [Y. Zhou, S. S. Wang, H. L. Liu, Y. L. Lam, Y. C. Chan, and C. H. Kam, EEE J. 8, 109 (1996).], the fluorescence is still considered weak for practical applications. We have used sol-gel aluminum codoping to increase the solubility of the Er3+ ions in a silica glass host and, consequently, significantly enhanced the fluorescence intensity of Er3+-doped sol-gel glass to the extent suitable for practical usage.

  14. Charge transport in tri-p-tolylamine doped trinaphthalylbenzene glass

    NASA Astrophysics Data System (ADS)

    Lin, Liang-Bih; O'Reilly, James M.; Magin, Edward H.; Weiss, David S.; Jenekhe, Samson A.

    2000-09-01

    The charge transport properties of tri-p-tolylamine (TTA) doped trinaphthalylbenzene have been measured as a function of electric field and temperature. The charge mobilities of the composite are comparable to but somewhat lower than that of TTA doped polystyrene, a nonpolar polymeric host, at similar weight fractions. We suggest that the difference is due to inhomogeneity between the host and the dopant. The results suggest that, similar to polymer hosts in molecularly doped polymers, the molecular host only functions as an inert diluter and does not directly participate in the charge transport manifold. The results also substantiate the importance of molecular packing to charge hopping in disordered organic materials. The charge mobility data are analyzed with a disorder model due to Bässler and coworkers and a recently modified expression due to Novikov and coworkers [Phys. Rev. Lett. 81, 4472 (1998)]. Both models provide adequate descriptions of charge transport in organic amorphous materials.

  15. Structural, thermal and spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application

    SciTech Connect

    Kesavulu, C.R.; Sreedhar, V.B.; Jayasankar, C.K.; Jang, Kiwan; Shin, Dong-Soo; Yi, Soung Soo

    2014-03-01

    Graphical abstract: - Highlights: Er{sup 3+}-doped novel oxyfluoride glasses have been prepared by melt quenching technique. Structural, thermal and spectroscopic properties have been carried out. SALSFEr glasses exhibit intense green and weak red emissions at 365 nm excitation. Major laser transition for Er{sup 3+} ion in SALSFEr glasses is {sup 4}I{sub 13/2} ? {sup 4}I{sub 15/2} (1.53 ?m). These results suggest the possibility of using SALSFEr glasses as photonic devices. - Abstract: The Er{sup 3+}-doped novel oxyfluoride glasses of composition (43 ? x)SiO{sub 2}10Al{sub 2}O{sub 3}24LiF23SrF{sub 2}xEr{sub 2}O{sub 3}, where x = 1.0, 2.0, 4.0 and 6.0 mol%, have been prepared by conventional melt quenching technique and are characterized through X-ray diffraction (XRD), differential thermal analysis (DTA), Raman, Fourier transform infrared (FT-IR) analysis, optical absorption spectra, visible (vis) and near-infrared (NIR) emission spectra measurements. JuddOfelt (JO) intensity parameters (?{sub ?}, ? = 2, 4 and 6) have been derived from the absorption spectrum of 1.0 mol% Er{sub 2}O{sub 3} doped glass and are in turn used to calculate radiative properties for the important luminescent levels of Er{sup 3+} ions. The studied glasses show intense green and weak red visible emissions under 365 nm excitation. The decrease in visible emission intensities with concentration of Er{sup 3+} ions has been explained due to energy transfer processes between Er{sup 3+} ions. Upon excitation at 980 nm laser diode, an intense 1.53 ?m NIR emission has been observed with the maximum full width at half maximum (FWHM) for Er{sup 3+}-doped oxyfluoride glasses. The higher Er{sup 3+} ion doping capability and relatively high gain and broad emission at 1.5 ?m are the most notable features of these glasses to realize efficient short-length optical amplifiers.

  16. Optical properties of Ce3+ doped fluorophosphates scintillation glasses

    NASA Astrophysics Data System (ADS)

    Yao, Yongxin; Liu, Liwan; Zhang, Yu; Chen, Danping; Fang, Yongzheng; Zhao, Guoying

    2016-01-01

    Fluorophosphates (P2O5-BaO-BaF2-Al2O3-Gd2O3-Ce2O3) glasses with different Gd2O3 and BaF2 concentrations have been prepared by a melt quenching method. The effect of Gd2O3 and BaF2 on the glass performance including the density, absorption as well as luminescence properties under both ultraviolet (UV) and X-ray excitation was studied systematically. Energy transfer from Gd3+ to Ce3+ plays an important role in the scintillation mechanism of these glasses and the optimum concentration of Gd2O3 is found to be approximately 3 mol%. The highest integrated light emission intensity of these glass samples excited by X-ray is 25% of BGO and the decay time constants are in the range of 25-35 ns, much shorter than the 300 ns decay time of BGO. Meanwhile, replacing lighter compound BaO with the BaF2 can increase the density of the glasses and also improve the light yield.

  17. The tetragonal structure of nanocrystals in rare-earth doped oxyfluoride glass ceramics.

    PubMed

    Hu, Nan; Yu, Hua; Zhang, Ming; Zhang, Pan; Wang, Yazhou; Zhao, Lijuan

    2011-01-28

    Rare-earth doped oxyfluoride glasses and nanocrystalline glass ceramics have been prepared and studied by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) aiming at investigating the structure and the symmetry of the nanocrystal as well as the site of the rare-earth ion. To solve the problem encountered by previous researchers due to glass host interference, we etched off glass matrix and released the fluoride nanocrystal, which is more convenient for EDS measurement. A tetragonal phase model with the chemical formula as PbREF(5) proved by quantitative EDS and XRD analyses has been proposed in this paper for the first time. Two specific crystalline phases with the same space group have been observed at 460 °C-500 °C and 520 °C-560 °C, respectively. Moreover, a super "pseudo-cubic" cell based on our tetragonal model may give a good explanation to the probable previous cubic-symmetry misunderstanding by researchers. Additionally, the thermodynamic mechanism of phase transition and the thermal stability related to the structure of nanocrystals in glass ceramics have been studied and supported by ab initio calculations and experimental methods. The structure and thermal stability of the nanocrystal and clear environment of the rare-earth ion reported here have far-reaching significance with respect to the optical investigations and further applications of rare-earth doped oxyfluoride glass ceramics. PMID:21152548

  18. Structural and optical study on antimony-silicate glasses doped with thulium ions.

    PubMed

    Dorosz, D; Zmojda, J; Kochanowicz, M; Miluski, P; Jelen, P; Sitarz, M

    2015-01-01

    Structural, spectroscopic and thermal properties of SiO?-Al?O?-Sb?O?-Na?O glass system doped with 0.2 mol% Tm?O? have been presented. Synthesis of antimony-silicate glasses with relatively low phonon energy (600 cm(-1), which implicates a small non-radiative decay rate) was performed by conventional high-temperature melt-quenching methods. The effect of SiO?/Sb?O? ratio in fabricated Tm(3+) doped glass on thermal, structural and luminescence properties was investigated. On the basis of structural investigations decomposition of absorption bands in the infrared FTIR region was performed, thus determining that antimony ions are the only glass-forming ions, setting up the lattice of fabricated glasses. Luminescence band at the wavelength of 1.8 ?m corresponding to (3)F??(3)H? transition in thulium ions was obtained under 795 nm laser pumping. It was observed that combination of relatively low phonon energy and greater separation of optically active centers in the fabricated glasses influenced in decreasing the luminescence intensity at 1800 nm. PMID:25049172

  19. Structural and optical study on antimony-silicate glasses doped with thulium ions

    NASA Astrophysics Data System (ADS)

    Dorosz, D.; Zmojda, J.; Kochanowicz, M.; Miluski, P.; Jelen, P.; Sitarz, M.

    2015-01-01

    Structural, spectroscopic and thermal properties of SiO2-Al2O3-Sb2O3-Na2O glass system doped with 0.2 mol% Tm2O3 have been presented. Synthesis of antimony-silicate glasses with relatively low phonon energy (600 cm-1, which implicates a small non-radiative decay rate) was performed by conventional high-temperature melt-quenching methods. The effect of SiO2/Sb2O3 ratio in fabricated Tm3+ doped glass on thermal, structural and luminescence properties was investigated. On the basis of structural investigations decomposition of absorption bands in the infrared FTIR region was performed, thus determining that antimony ions are the only glass-forming ions, setting up the lattice of fabricated glasses. Luminescence band at the wavelength of 1.8 ?m corresponding to 3F4 ? 3H6 transition in thulium ions was obtained under 795 nm laser pumping. It was observed that combination of relatively low phonon energy and greater separation of optically active centers in the fabricated glasses influenced in decreasing the luminescence intensity at 1800 nm.

  20. Tm? doped barium gallo-germanate glass single-mode fibers for 2.0 ?m laser.

    PubMed

    Wen, Xin; Tang, Guowu; Wang, Jinwen; Chen, Xiaodong; Qian, Qi; Yang, Zhongmin

    2015-03-23

    Tm? doped barium gallo-germanate (BGG) glass has emerged as a promising 2.0 ?m laser material offering excellent optical property. Unfortunately, low anti-crystallization ability and high OH? content of the glass have hindered the fabrication of high-quality optical fibers. In this paper, La?O? and Y?O? were added into BGG glass to enhance the glass anti-crystallization ability. Additionally, the optimized Reaction Atmosphere Procedure (RAP) was utilized to minimize OH? content. Continuous Tm? doped BGG glass single-mode (SM) fibers were successfully obtained by the rod-in-tube technique for the first time to our best knowledge. A 140 mW all-fiber laser at 1.95 ?m was demonstrated using a 9.7-cm-long as-drawn Tm? doped BGG glass SM fiber upon excitation of a home-made 1568 nm fiber laser. PMID:25837110

  1. Electrophoretic Deposition of Chitosan/45S5 Bioactive Glass Composite Coatings Doped with Zn and Sr

    PubMed Central

    Miola, Marta; Verné, Enrica; Ciraldo, Francesca Elisa; Cordero-Arias, Luis; Boccaccini, Aldo R.

    2015-01-01

    In this research work, the original 45S5 bioactive glass was modified by introducing zinc and/or strontium oxide (6 mol%) in place of calcium oxide. Sr was added for its ability to stimulate bone formation and Zn for its role in bone metabolism, antibacterial properties, and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology while compositional analysis (EDS) demonstrated the effective incorporation of these elements in the glass network. Bioactivity test in simulated body fluid (SBF) up to 1 month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD). Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD) and alternating current EPD (AC-EPD). The stability of the suspension was analyzed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, whereas the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover, the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses, and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behavior of 45S5-Sr-containing coating while coatings containing Zn exhibited no hydroxyapatite formation. PMID:26539431

  2. Integrated optical amplifiers and microspherical lasers based on erbium-doped oxide glasses

    NASA Astrophysics Data System (ADS)

    Righini, G. C.; Arnaud, C.; Berneschi, S.; Bettinelli, M.; Brenci, M.; Chiasera, A.; Feron, P.; Ferrari, M.; Montagna, M.; Nunzi Conti, G.; Pelli, S.; Portales, H.; Siligardi, C.; Speghini, A.; Zampedri, L.

    2005-10-01

    Er3+-doped glasses have been a subject of great interest in the recent years for their application in the areas of guided wave optical amplifiers and lasers. Oxide-glass matrices, in particular, offer the advantage of relatively simple fabrication processes-both for bulk glasses and optical fibers-and have demonstrated quite good properties in the 1.5 ?m wavelength band. Here we present some results we have obtained in the development of different silica-based glasses and in their application to the production of integrated optical amplifiers and microspherical lasers. As to the former application, two classes of silica glasses have been produced and investigated, namely a melted soda-lime-alumino-silicate glass and a sol-gel silica-hafnia glass. Both of them exhibit a wide emission bandwidth and seem quite promising for broadband optical amplifiers. We also demonstrated low-threshold microlasers, based on whispering gallery mode spherical resonators, fabricated in different oxide glasses.

  3. Spectroscopic properties and energy transfer in Er-Tm co-doped bismuth silicate glass

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Li, Zhilan; Li, Kefeng; Zhang, Lei; Cheng, Jimeng; Hu, Lili

    2013-10-01

    In this paper, we investigate the spectroscopic properties of and energy transfer processes in Er-Tm co-doped bismuth silicate glass. The Judd-Ofelt parameters of Er3+ and Tm3+ are calculated, and the similar values indicate that the local environments of these two kinds of rare earth ions are almost the same. When the samples are pumped at 980 nm, the emission intensity ratio of Tm:3F4 ? 3H6 to Er:4I13/2 ? 4I15/2 increases with increased Er3+ and Tm3+ contents, indicating energy transfer from Er:4I13/2 to Tm:3F4. When the samples are pumped at 800 nm, the emission intensity ratio of Er:4I13/2 ? 4I15/2 to Tm:3H4 ? 3F4 increases with increased Tm2O3 concentration, indicating energy transfer from Tm:3H4 to Er:4I13/2. The rate equations are given to explain the variations. The microscopic and macroscopic energy transfer parameters are calculated, and the values of energy transfer from Er:4I13/2 to Tm:3F4 are found to be higher than those of the other processes. For the Tm singly-doped glass pumped at 800 nm and Er-Tm co-doped glass pumped at 980 nm, the pumping rate needed to realize population reversion is calculated. The result shows that when the Er2O3 doping level is high, pumping the co-doped glass by a 980 nm laser is an effective way of obtaining a low-threshold 2 ?m gain.

  4. EPR, optical absorption and luminescence studies of Cr3+-doped antimony phosphate glasses

    NASA Astrophysics Data System (ADS)

    De Vicente, F. S.; Santos, F. A.; Simes, B. S.; Dias, S. T.; Siu Li, M.

    2014-12-01

    Antimony phosphate glasses (SbPO) doped with 3 and 6 mol% of Cr3+ were studied by Electron Paramagnetic Resonance (EPR), UV-VIS optical absorption and luminescence spectroscopy. The EPR spectra of Cr3+-doped glasses showed two principal resonance signals with effective g values at g = 5.11 and g = 1.97. UV-VIS optical absorption spectra of SbPO:Cr3+ presented four characteristics bands at 457, 641, 675, and 705 nm related to the transitions from 4A2(F) to 4T1(F), 4T2(F), 2T1(G), and 2E(G), respectively, of Cr3+ ions in octahedral symmetry. Optical absorption spectra of SbPO:Cr3+ allowed evaluating the crystalline field Dq, Racah parameters (B and C) and Dq/B. The calculated value of Dq/B = 2.48 indicates that Cr3+ ions in SbPO glasses are in strong ligand field sites. The optical band gap for SbPO and SbPO:Cr3+ were evaluated from the UV optical absorption edges. Luminescence measurements of pure and Cr3+-doped glasses excited with 350 nm revealed weak emission bands from 400 to 600 nm due to the 3P1 ? 1S0 electronic transition from Sb3+ ions. Cr3+-doped glasses excited with 415 nm presented Cr3+ characteristic luminescence spectra composed by two broad bands, one band centered at 645 nm (2E ? 4A2) and another intense band from 700 to 850 nm (4T2 ? 4A2).

  5. Spectroscopic characteristics of chromium doped mullite glass-ceramics

    SciTech Connect

    Wojtowicz, A.J.; Meng, W.; Lempicki, A.; Beall, G.H.; Hall, D.W.; Chin, T.C.

    1988-06-01

    Characteristics of chromium doped mullite ceramics are discussed with reference to possible laser applications. Dominant features are attributed to large and inherent spectroscopic inhomogeneity of mullite. The spectroscopic data are analyzed using a generalized McCumber theory. The peak stimulated emission cross section is 0.54 x 10/sup -20/ cm/sup 2/. This, together with preliminary single-pass measurements, indicate that gain for mullite is about 2.6 times smaller than gain for alexandrite.

  6. Thermal and spectroscopic properties of Nd3+-doped novel fluorogallate glass

    NASA Astrophysics Data System (ADS)

    Xue, Tianfeng; Zhang, Liyan; Hu, Junjiang; Liao, Meisong; Hu, Lili

    2015-09-01

    An Nd3+-doped fluorogallate glass with better thermal stability (Tg = 650.5 C, ?T = 190 C), and lower linear thermal expansion coefficient (8.7 10-6/C) compared with other commercialized laser glasses is reported in this paper. Judd-Ofelt theory is applied to the absorption spectrum of the glass to derive the intensity parameters (?t), which are in turn used to calculate the radiative properties of Nd3+ luminescent levels. The developed glass possesses the widest effective emission bandwidth (??eff = 49 nm) ever reported at around 1.07 ?m, large gain bandwidth parameter (?em ??eff = 102.9 10-27 cm3), and high fluorescence quantum efficiency (? = 66%). These results indicate that this new kind of material is an interesting candidate for laser applications.

  7. Spectroscopic properties of Er3+ doped lead phosphate glasses for photonic application 4-23-2009

    SciTech Connect

    Santos, C. C.; Guedes, I.; Moura, A. L. Moura; de Araujo, M. T.; Jacinto, C.; Vermelho, M. V. D.; Loong, C. K.; Boatner, Lynn A

    2010-01-01

    The spectroscopic characteristics of Er3+-doped lead phosphate glasses have been investigated, and Judd-Ofelt analysis was used to evaluate the effect of increasing the Er3+ content on the glass matrices. The intensity-dependent Judd=-Ofelt parameters: (4) and (6) remained constant while (2) decreased. Photoluminescence analysis revealed a low up-conversion efficiency through the weak green (530 and 550 nm) and red (660 nm) signals that were present under excitation at 800 nm. The concentration quenching effect on the lifetime of the Er3+: 4I13/2 4I15/2 (1530 nm) transition is also evaluated as a result of the addition of Er3+ to the lead phosphate glass composition. The observed relatively large reduction in the lifetime reflects the significant effects of non-radiative processes in this system. The potential use of these glasses as photonic devices is also discussed.

  8. Ultraviolet and white photon avalanche upconversion in Ho{sup 3+}-doped nanophase glass ceramics

    SciTech Connect

    Lahoz, F.; Martin, I.R.; Calvilla-Quintero, J.M.

    2005-01-31

    Ho{sup 3+}-doped fluoride nanophase glass ceramics have been synthesized from silica-based oxyfluoride glass. An intense white emission light is observed by the naked eye under near infrared excitation at 750 nm. This visible upconversion is due to three strong emission bands in the primary color components, red, green, and blue. Besides, ultraviolet signals are also recorded upon the same excitation wavelength. The excitation mechanism of both the ultraviolet and the visible emissions is a photon avalanche process with a relatively low pump power threshold at about 20 mW. The total upconverted emission intensity has been estimated to increase by about a factor of 20 in the glass ceramic compared to the precursor glass, in which an avalanche type mechanism is not generated.

  9. Cobalt-Doped Transparent Glass Ceramic as a Saturable Absorber Q Switch for Erbium:Glass Lasers

    NASA Astrophysics Data System (ADS)

    Malyarevich, Alexander M.; Denisov, Igor A.; Yumashev, Konstantin V.; Dymshits, Olga S.; Zhilin, Alexander A.; Kang, Uk

    2001-08-01

    A new saturable absorber Q switch for 1.54- m Er:glass lasers is presented. The saturable absorber is a transparent glass ceramic that contains magnesium -aluminum spinel nanocrystallites doped with tetrahedrally coordinated Co2 +ions. We obtained Q -switched pulses of up to 5.5 mJ in energy and 80 ns in duration at 1.54 m. The relaxation time of 4A2 4T1 (4F ) transition bleaching was measured to be (450 -/+ 150) ns. Ground-state and excited-state absorption cross sections at 1.54- m wavelength were estimated to be (3.2 -/+ 0.4) x10-19 cm2 and (5.0 -/+ 0.6) x10-20 cm2 , respectively.

  10. [Investigation on the fabrication and spectrum properties of Yb3+ -doped silicate laser glasses].

    PubMed

    Dong, Shi-rui; Hou, Lan-tian; Jin, Tao-tao; Han, Ying; Xia, Chang-ming; Niu, Jing-xia; Zhou, Gui-yao; Liang, Dan-hua; Li, Rui

    2009-09-01

    Two kinds of Yb3+ doped silicate laser glass with little difference were produced by high temperature of melting process. The absorption and emission spectra of the two glass samples were tested by the correlative spectrographs; the integral absorption cross section, stimulated emission cross section, fluorescence line-width, fluorescence lifetime, least particle count, saturation pump intensity and least pump intensity of the Yb3+ -doped laser glasses were calculated respectively, and by comparison it was found that the chart of the absorption cross section is similar to the stimulated emission cross section calculated by the reciprocity method, and is very different from the stimulated emission cross section calculated by the Fuchbauer-Ladenburger method. This result is precisely in line with the theoretical analysis. The line-types of the absorption spectra of the two glass samples are almost the same, and the first peak value of absorption is located at 975 nm while the second peak value is at 908 nm. As the two components of the samples are not very different, the accord of the line-types of the absorption spectra indicates that the makeup of the glass material is the primary factor influencing the line-type of the absorption spectra. The fluorescence spectra of the two glass samples are very different, and the first fluorescence peak value of sample one is located at 993 nm with the second peak value at 1029 nm, while the first fluorescence peak value of sample two is located at 1 035 nm with the second peak value at 994 nm. The cause of the major difference in the fluorescence spectra of two samples lies in the different doping density of Yb3+. By comparison we found that the laser performance of sample two is better than that of sample one. The test shows that both samples are suitable for drawing fiber. PMID:19950658

  11. Physical and optical properties of lead doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Riyatun; Rahmasari, Lita; Marzuki, Ahmad

    2016-02-01

    Physical and optical properties of lead telluride (Pb:TZBN) glasses with composition 55TeO2-(41-x)ZnO-2Bi2O3-2Na2O-xPbO where x = 1.0, 1.5, 2.0, 2.5% mol are presented. UV-VIS-NIR spectra of the glasses in the range of 300 - 800 nm along with their densities and refractive indices at 746 nm were recorded at room temperature. The optical bandgap energy (Eg) has been calculated from the fitting of Tauc plot. On the basis of these results we found that with the increase of Pb2+ content, their refractive indices are increased while their optical bandgaps are decreased. From this experiment, no distinct relationship between the Pb2+ content variation and the electronic polarizability (αO2-) as well as their optical basicity values (A) were observed.

  12. Optical Characterization of Nd3+ and Er3+ Doped-Lead-Indium Phosphate Glasses

    SciTech Connect

    Brito, Taisa B.; Vermelho, M. V. D.; Gouveia, E. A.; de Araujo, M. T.; Guedes, I.; Loong, C. K.; Boatner, Lynn A

    2007-01-01

    In this work, Judd-Ofelt analysis is applied to rare-earth-doped lead-indium-phosphate glasses (RE-PbInPO{sub 4}, where RE = Er{sup 3+} and Nd{sup 3+}) in order to evaluate their potential as both glass laser systems and amplifier materials. The phenomenological Judd-Ofelt parameters {Omega}{sub (2)}, {Omega}{sub (4)}, and {Omega}{sub (6)} are determined for both rare-earth ions together with their quality factors and compared with the equivalent parameters for several other host glasses. The spontaneous emission probabilities and the lifetimes of the Nd{sup 3+} {sup 4}F{sub 3/2} laser transitions are determined and analyzed as a function of the optical quality factor. For Nd{sup 3+}-PbInPO{sub 4}, glass fluorescence emission (890, 1058, and 1330 nm) lines are observed. Highly efficient infrared-to-visible frequency up-conversion at 530, 550, and 670 nm as well as an intense infrared fluorescence emission ({approx}1540 nm) is observed in Er{sup 3+}-doped PbIn(PO{sub 4}) glasses pumped using 800 nm radiation excitation.

  13. Optical, Structural, and Thermal Properties of Cerium-Doped Zinc Borophosphate Glasses.

    PubMed

    Choi, Su-Yeon; Ryu, Bong-Ki

    2015-11-01

    In this study, we verify the relationship between the optical properties and structure of cerium-doped zinc borophosphate glasses that have concurrence of non-bridging oxygen (NBO) and bridging oxygen (BO), Ce3+ and Ce4+, and BO3 structure and BO4 structure. We prepared cerium-doped zinc borophosphate glass with various compositions, given by xCeO2-(100-x)[50ZnO-10B2O3 -40P2O5] (x = 1 mol% to 6 mol%), and analyzed their optical band energy, glass transition temperature, crystallization temperature, density, and molar volume. Some of the techniques used for analysis were Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). In the investigated glasses, the optical band gap energy decreased from 3.28 eV to 1.73 eV. From these results, we can deduce the changes when transitions occur from BO to NBO, from Ce3+ to Ce4+, and from the BO3 structure to the BO4 structure with increasing CeO2 content using FT-IR and XPS analysis. We also verified the changes in structural and physical properties from quantitative properties such as glass transition temperature, crystallization temperature, density, and molar volume. PMID:26726590

  14. Temperature dependent luminescence characteristics of Sm3+-doped silicate glass.

    PubMed

    Annapurna, K; Dwivedi, R N; Kumar, A; Chaudhuri, A K; Buddhudu, S

    2000-01-01

    We report here on the optical characterisation of Sm3+ (5 wt%): SiO2 + Al2O3 + Li2O + Na2O + MgO glass from the measurements of optical absorption spectra (at 300 K), total luminescence spectra (10-300 K) and fluorescence lifetimes (10-300 K) of the prominent emission transitions of the Sm3+ ions. Besides its spectral properties, physical and nonlinearity characterising property parameters have also been computed to understand the optical dispersive power of this glass. By the application of Judd-Ofelt parameters (omega(lambda)) of the measured absorption spectrum, the radiative transition probability factors (A) and stimulated emission cross-section (sigma(p)E) of the observed fluorescent levels have been analysed. Both emission intensity and measured lifetimes of the prominent luminescent transition (4G(5/2) --> 6H(7/2)) concerning Sm3+-glass has been showing a descending trend with the rise in temperature with N2-laser (337.1 nm) as the source of excitation. PMID:10728859

  15. Mechanisms of the refractive index change in femtosecond laser-irradiated Au3+-doped silicate glasses

    NASA Astrophysics Data System (ADS)

    Zhao, Quan-Zhong; Qiu, Jian-Rong; Jiang, Xiong-Wei; Zhao, Chong-Jun; Zhu, Cong-Shan

    2004-12-01

    We report on the refractive index change in Au3+-doped silicate glasses irradiated by a femtosecond laser and successive heat treatment. The refractive index of the irradiated area increased after the femtosecond laser irradiation and decreased with increasing annealing temperature up to 450C and then increased again with increasing annealing temperature. Absorption spectra of the glass samples before and after femtosecond laser irradiation and after further annealing manifested the formation of color centers after laser irradiation, disappearance of color centers after annealing at 300C, and precipitation of gold nanoparticles after annealing at high temperature. The mechanisms of the observed phenomena are discussed.

  16. Optical absorption and luminescence study of cobalt-doped magnesium aluminosilicate glass ceramics

    NASA Astrophysics Data System (ADS)

    Malyarevich, A. M.; Denisov, I. A.; Yumashev, K. V.; Dymshits, O. S.; Zhilin, A. A.

    2002-08-01

    Linear and nonlinear optical properties of cobalt-doped magnesium aluminosilicate transparent glass ceramics that were prepared under different conditions have been studied. It has been shown that absorption and luminescence spectra and absorption bleaching of these glass ceramics are defined mainly by tetrahedrally coordinated Co 2+ ions located in magnesium aluminum spinel nanocrystals. The lifetimes of the 4 T 1 ( 4 F) and 4 T 2 ( 4 F) excited states of the tetrahedral Co 2+ ions were found to be in the ranges 2540 and 120450 ns, respectively, depending on the Co concentration. 2002 Optical Society of America

  17. Upconversion lasing of a thulium-ion-doped fluorozirconate glass microsphere

    NASA Astrophysics Data System (ADS)

    Fujiwara, Hideki; Sasaki, Keiji

    1999-09-01

    Blue and red upconversion lasing of a Tm3+-doped fluorozirconate glass microsphere was demonstrated. Tens-of-micrometer-sized, genuinely spherical glass particles were produced by a melting method with a burner. The single microsphere was pumped by a focused beam of a Nd:YAG laser operating at 1064 nm. Three-photon-excited lasing emission could be observed in 480 and 800 nm regions at room temperature, and their lasing thresholds were determined to be 20 and 5 mW, respectively. Applications of the microspherical upconversion laser to near-field scanning optical microscopy are also discussed.

  18. Energy Transfer Process of Eu3+ Ions Doped in Tellurite Glass

    NASA Astrophysics Data System (ADS)

    Hong, Tran Thi; Dung, Phan Tien; Quang, Vu Xuan

    2016-03-01

    Tellurite glass doped with different concentrations of Eu3+ ions has been prepared by the conventional melting process. Photoluminescence, Raman spectra, phonon side-band spectra, and Judd-Ofelt analysis were carried out. Some spectroscopic parameters were estimated to predict the luminescence efficiency of the materials. The energy transfer between the rare-earth ions was observed, and a model for its cross-relaxation was proposed and quantitatively estimated. The charged intrinsic defects in the form of nonbridging oxygen (NBO) were determined, and the energy transfer between NBO and rare-earth ions observed. The energy-transfer-induced Eu3+ photoluminescence enhancement in tellurite glass is studied.

  19. Optical transitions and upconversion fluorescence in Ho3+/Yb3+ doped bismuth tellurite glasses

    NASA Astrophysics Data System (ADS)

    Wang, Xueying; Lin, Hai; Yang, Dianlai; Lin, Lin; Yue-Bun Pun, Edwin

    2007-06-01

    10mol% of bismuth oxide was designed to add in making novel Ho3+ doped heavy metal tellurite glasses (LKBBT) with large refractive indices and glass densities. Based on optical absorption, Judd-Ofelt parameters ?2, ?4, and ?6 have been derived to be 4.37310-20, 1.90610-20, and 1.45110-20cm2, respectively, which indicate higher asymmetry and stronger covalent environment in LKBBT glasses compared with ZnF2-CdF2, oxyfluorobotate, and zirconium-barium-lanthanum-aluminum-sodium-fluoride glasses. Efficient visible upconversion emission bands peaked at 544, 657, and 753nm in Ho3+/Yb3+ codoped LKBBT glass system have confirmed that two photons contribute to the upconversion processes under the pumping of a 974nm diode laser. Owing to large absorption and emission cross sections, Yb3+ ion is considered to be a preferable sensitizer for catching enough pumping energy and transferring considerable energy to Ho3+ in LKBBT glasses. Low maximum phonon energy and high spontaneous transition probabilities of Ho3+ are beneficial in obtaining efficient upconversion and IR emission in the glass system.

  20. Long-term test results from a West Valley actinide-doped reference glass

    SciTech Connect

    Fortner, J.A.; Gerding, T.J.; Bates, J.K.

    1995-07-01

    Results from drip tests designed to simulate unsaturated conditions in the proposed Yucca Mountain Repository are reported for an actinide-doped glass (reference glass ATM-10) used as a model waste form. These tests have been ongoing for nearly 7 years, with data collected on solution composition (including transuranics), colloid formation and disposition, glass corrosion layers, and solid secondary phases. This test is unique because of its long elapsed time, high content of thorium and transuranics, use of actual groundwater from the proposed site area, use of contact between the glass and sensitized stainless steel in the test, and the variety of analytical procedures applied to the components. Some tests have been terminated, and scanning electron microscopy (SEM) and analytical transmission electron microscopy (AEM) were used to directly measure glass corrosion and identify secondary phases. Other tests remain ongoing, with periodic sampling of the water that had contacted the glass. The importance of integrated testing has been demonstrated, as complex interactions between the glass, the groundwater, and the sensitized stainless steel have been observed. Secondary phases include smectite clay, iron silicates, and brockite. Actinides, except neptunium, concentrate into stable secondary phases. The release of actinides is then controlled by the behavior of these phases.

  1. Comparison of Borate Bioactive Glass and Calcium Sulfate as Implants for the Local Delivery of Teicoplanin in the Treatment of Methicillin-Resistant Staphylococcus aureus-Induced Osteomyelitis in a Rabbit Model.

    PubMed

    Jia, Wei-Tao; Fu, Qiang; Huang, Wen-Hai; Zhang, Chang-Qing; Rahaman, Mohamed N

    2015-12-01

    There is growing interest in biomaterials that can cure bone infection and also regenerate bone. In this study, two groups of implants composed of 10% (wt/wt) teicoplanin (TEC)-loaded borate bioactive glass (designated TBG) or calcium sulfate (TCS) were created and evaluated for their ability to release TEC in vitro and to cure methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in a rabbit model. When immersed in phosphate-buffered saline (PBS), both groups of implants provided a sustained release of TEC at a therapeutic level for up to 3 to 4 weeks while they were gradually degraded and converted to hydroxyapatite. The TBG implants showed a longer duration of TEC release and better retention of strength as a function of immersion time in PBS. Infected rabbit tibiae were treated by debridement, followed by implantation of TBG or TCS pellets or intravenous injection with TEC, or were left untreated. Evaluation at 6 weeks postimplantation showed that the animals implanted with TBG or TCS pellets had significantly lower radiological and histological scores, lower rates of MRSA-positive cultures, and lower bacterial loads than those preoperatively and those of animals treated intravenously. The level of bone regeneration was also higher in the defects treated with the TBG pellets. The results showed that local TEC delivery was more effective than intravenous administration for the treatment of MRSA-induced osteomyelitis. Borate glass has the advantages of better mechanical strength, more desirable kinetics of release of TEC, and a higher osteogenic capacity and thus could be an effective alternative to calcium sulfate for local delivery of TEC. PMID:26416858

  2. Simulations of silver-doped germanium-selenide glasses and their response to radiation

    NASA Astrophysics Data System (ADS)

    Prasai, Kiran; Drabold, David A.

    2014-10-01

    Chalcogenide glasses doped with silver have many applications including their use as a novel radiation sensor. In this paper, we undertake the first atomistic simulation of radiation damage and healing in silver-doped Germanium-selenide glass. We jointly employ empirical potentials and ab initio methods to create and characterize new structural models and to show that they are in accord with many experimental observations. Next, we simulate a thermal spike and track the evolution of the radiation damage and its eventual healing by application of a simulated annealing process. The silver network is strongly affected by the rearrangements, and its connectivity (and thus contribution to the electrical conductivity) change rapidly in time. The electronic structure of the material after annealing is essentially identical to that of the initial structure.

  3. PAL spectroscopy of rare-earth doped Ga-Ge-Te/Se glasses

    NASA Astrophysics Data System (ADS)

    Shpotyuk, Ya.; Ingram, A.; Shpotyuk, O.

    2016-04-01

    Positron annihilation lifetime (PAL) spectroscopy was applied for the first time to study free-volume void evolution in chalcogenide glasses of Ga-Ge-Te/Se cut-section exemplified by glassy Ga10Ge15Te75 and Ga10Ge15Te72Se3 doped with 500 ppm of Tb3+ or Pr3+. The collected PAL spectra reconstructed within two-state trapping model reveal decaying tendency in positron trapping efficiency in these glasses under rare-earth doping. This effect results in unchanged or slightly increased defect-related lifetimes τ2 at the cost of more strong decrease in I2 intensities, as well as reduced positron trapping rate in defects and fraction of trapped positrons. Observed changes are ascribed to rare-earth activated elimination of intrinsic free volumes associated mainly with negatively-charged states of chalcogen atoms especially those neighboring with Ga-based polyhedrons.

  4. Simulations of silver-doped germanium-selenide glasses and their response to radiation

    PubMed Central

    2014-01-01

    Chalcogenide glasses doped with silver have many applications including their use as a novel radiation sensor. In this paper, we undertake the first atomistic simulation of radiation damage and healing in silver-doped Germanium-selenide glass. We jointly employ empirical potentials and ab initio methods to create and characterize new structural models and to show that they are in accord with many experimental observations. Next, we simulate a thermal spike and track the evolution of the radiation damage and its eventual healing by application of a simulated annealing process. The silver network is strongly affected by the rearrangements, and its connectivity (and thus contribution to the electrical conductivity) change rapidly in time. The electronic structure of the material after annealing is essentially identical to that of the initial structure. PMID:25426005

  5. Fabrication and properties of Yb-doped silica glass films for laser waveguide application

    NASA Astrophysics Data System (ADS)

    Jacqueline, A.-S.; Petit, V.; Gourbilleau, F.; Camy, P.; Doualan, J.-L.; Moncorg, R.; Rizk, R.

    2006-05-01

    This paper describes the fabrication of Yb 3+-doped silica glass films prepared by RF magnetron sputtering for laser applications. The deposition parameters and the subsequent thermal treatments were accurately adjusted to obtain layers with appropriate structural characteristics (flat surface, homogeneity) and optical properties (refractive index, absorption and fluorescence emission). The structural properties of the deposited films have been investigated by infra-red absorption spectroscopy and atomic force microscopy, while the layer composition was determined by an Energy Dispersive X-ray spectrometer. The optical properties of the films have been investigated by time resolved photoluminescence, providing relevant parameters such as the Yb 3+ fluorescence lifetime that governs the high pump energy storage and laser efficiency. The obtained values of the lifetime are scaling from 50 to 610 ?s, and therefore are comparable to those usually reported for Yb 3+-doped silica glass fibers.

  6. Spectral transmittance of organic dye-doped glass films obtained by the solgel method

    NASA Astrophysics Data System (ADS)

    Nemoto, Shojiro; Hirokawa, Naoyuki

    1996-06-01

    The spectral transmittance of colored glass films synthesized by the solgel method is presented. The film was formed on a glass slide by dipping it into an organic dye-doped solution and, thereafter, by putting it into a furnace for solidification. Three dyes, Methylene Blue, Eosin, and Uranine, were used that exhibit transparent blue, pink, and yellow colors, respectively, when they are dissolved in the starting solution. We clarify how the spectral transmittance of the films varies with the solidification temperature. The films doped with two of the three dyes that exhibit violet, orange, and green colors are also synthesized, and their transmittance is measured. Moreover, the chemical durability of the films and the transmittance change caused by aging and illumination are examined. organic dye, solgel method.

  7. Low-power nonlinear optical interaction in dye-doped sol-gel glasses

    NASA Astrophysics Data System (ADS)

    Lam, Sio K.; Chan, Man-shih A.; Lo, Dennis Y.

    2000-11-01

    Organic dye-doped solids show strong third-order optical non-linearity due to the enhancement of the lifetime of the lowest triplet state of the dye in solid environment. The long triplet state lifetime leads to low absorption saturation intensity. As a result, the third order nonlinear optical behavior is observable at very low light power (i.e. tens of mW). Dye-doped solid of large third order nonlinearity finds application in many photonic devices. Boric acid glass, polymer (such as PMMA, PVA, PAA), sol-gel silica, and organically modified sol-get silicate (ORMOSIL) have been used as host materials for dyes. We will concentrate our interest on the dye-doped sol-gel silica and dye-doped ORMOSIL. We have performed degenerate four wave mixing (DFWM) experiment to demonstrate optical phase conjugation by eosin Y-doped sol-gel silica in vacuum ambient. We have also performed Z-scan measurement to study the nonlinear refractive index of fluorescein 548- doped ORMOSIL. Absorption saturation experiments are conducted to determine the absorption intensity and (chi) (3).

  8. Coordination Environment and Network Structure in AgI Doped As-CHALCOGENIDE Glasses

    NASA Astrophysics Data System (ADS)

    Usuki, Takeshi; Nakajima, Kohei; Kameda, Yasuo; Sakurai, Masaki; Nasu, Toshio

    2007-01-01

    Diffraction measurements and extended X-ray absorption fine structure (EAXFS) studies together with their electrical and thermal properties have been carried out for (AgI)x(As2Se3)1-x glasses in order to investigate the ionic conduction mechanism in AgI-doped chalcogenide glasses. The addition of AgI into As2Se3 glass is responsible for a pronounced increase in the electrical conductivity. EXAFS and diffraction measurements result in the concentration independence of all structural parameters, where As has three Se nearest neighbours at 2.41 and Ag has four I nearest neighbours at 2.78 , respectively. This suggests that the network matrix in the glass is made by covalent As(Se1/2)3 pyramidal units and that a significant number of Ag ions have the tetrahedral coordination with I atoms, similar to the case in crystalline ?-AgI. It is also suggested that one of the main effects of AgI doping is to expand the interlayer distance between As(Se1/2)3 helical chains. Therefore, the structure model for the present (AgI)x(As2Se3)1-x glasses can be proposed as the pseudo-binary mixture of the As(Se1/2)3 network matrix and AgI-related conduction pathways. Structural characteristics of the host As2Se3 glass with flexible and strong networks play an important role in the ionic conduction of Ag+ in the present glasses.

  9. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    SciTech Connect

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C. Kasap, S. O.; Edgar, A.; Varoy, C.; Belev, G.; Wysokinski, T.; Chapman, D.; Sammynaiken, R.

    2014-02-14

    Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm{sup 3+}) can be used as a dosimetric detector in microbeam radiation therapy (MRT) to measure high radiation doses and large dose variations with a resolution in the micrometer range. The present work addresses the use of intense optical radiation at 405 nm to erase the recorded dose information in Sm{sup 3+}-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm{sup 3+}-doped FP glasses using synchrotron-generated high-dose x-rays at the Canadian Light Source. The Sm-ion valency conversion is accompanied by the appearance of x-ray induced optical absorbance due to the trapping of holes and electrons into phosphorus-oxygen hole (POHC) and electron (POEC) capture centers. Nearly complete Sm{sup 2+} to Sm{sup 3+} reconversion (erasure) may be achieved by intense optical illumination. Combined analysis of absorbance and electron spin resonance measurements indicates that the optical illumination causes partial disappearance of the POHC and the appearance of new POEC. The suggested model for the observed phenomena is based on the release of electrons during the Sm{sup 2+} to Sm{sup 3+} reconversion process, the capture of these electrons by POHC (and hence their disappearance), or by PO groups, with the appearance of new and/or additional POEC. Optical erasure may be used as a practical means to erase the recorded data and permits the reuse of these Sm-doped FP glasses in monitoring dose in MRT.

  10. Promethium-doped phosphate glass laser at 933 and 1098 nm

    SciTech Connect

    Krupke, W.F.; Shinn, M.D.; Kirchoff, T.A.; Finch, C.B.; Boatner, L.A.

    1987-12-28

    A promethium (Pm/sup 3 +/) laser has been demonstrated for the first time. Trivalent promethium 147 doped into a lead-indium-phosphate glass etalon was used to produce room-temperature four-level laser emission at wavelengths of 933 and 1098 nm. Spectroscopic and kinetic measurements have shown that Pm/sup 3 +/ is similar to Nd/sup 3 +/ as a laser active ion.

  11. Upconversion luminescence in bismuth-doped germano-silicate glass optical fiber

    NASA Astrophysics Data System (ADS)

    Fan, Weiwei; Htein, Lin; Kim, Bok Hyeon; Watekar, Pramod R.; Han, Won-Taek

    2013-12-01

    We report, for the first time, a broadband upconversion emission (800-1000 nm) in Bi-doped germano-silicate glass optical fibers with excitation in the range of 1515-1585 nm, which can explain the low laser efficiency at wavelengths longer than 1500 nm. The mechanism responsible for the emission is two-step upconversion process. The origin of this upconversion luminescence is discussed and new energy transition schemes are proposed.

  12. Energy transfer upconversion on neodymium doped phosphate glasses investigated by Z-scan technique

    NASA Astrophysics Data System (ADS)

    Lima, W. J.; Martins, V. M.; Monte, A. F. G.; Messias, D. N.; Dantas, N. O.; Bell, M. J. V.; Catunda, T.

    2013-07-01

    Time-resolved Z-scan measurements were employed to characterize energy transfer upconversion on the phosphate glass matrix, named PAN (P2O5-Al2O3-Na2CO3), doped with increasing Nd3+ concentrations. It was observed a linear dependence of the upconversion parameter with the dopant agent, which indicates the presence of a static and dynamic energy transfer processes. The critical inversion density was also evaluated for the same set of samples.

  13. DBR and DFB Lasers in Neodymium- and Ytterbium-Doped Photothermorefractive Glasses

    NASA Technical Reports Server (NTRS)

    Ryasnyanskiy, Aleksandr; Vorobiev, N.; Smirnov, V.; Lumeau, J.; Glebov, A.; Mokhun, O..; Spiegelberg, Ch.; Krainak, Michael A.; Glebov, A.; Glebov, L.

    2014-01-01

    The first demonstration, to the best of our knowledge, of distributed Bragg reflector (DBR) and monolithic distributed feedback (DFB) lasers in photothermorefractive glass doped with rare-earth ions is reported. The lasers were produced by incorporation of the volume Bragg gratings into the laser gain elements. A monolithic single-frequency solid-state laser with a line width of 250 kHz and output power of 150 mW at 1066 nm is demonstrated.

  14. DBR and DFB lasers in neodymium- and ytterbium-doped photothermorefractive glasses.

    PubMed

    Ryasnyanskiy, A; Vorobiev, N; Smirnov, V; Lumeau, J; Glebova, L; Mokhun, O; Spiegelberg, Ch; Krainak, Michael; Glebov, A; Glebov, L

    2014-04-01

    The first demonstration, to the best of our knowledge, of distributed Bragg reflector (DBR) and monolithic distributed feedback (DFB) lasers in photothermorefractive glass doped with rare-earth ions is reported. The lasers were produced by incorporation of the volume Bragg gratings into the laser gain elements. A monolithic single-frequency solid-state laser with a linewidth of 250 kHz and output power of 150 mW at 1066 nm is demonstrated. PMID:24686699

  15. Nonlinear optical effects on the surface of acridine yellow-doped lead-tin fluorophosphate glass

    NASA Technical Reports Server (NTRS)

    He, K. X.; Bryant, William; Venkateswarlu, Putcha

    1991-01-01

    The second- and third-order nonlinear optical properties of acridine yellow-doped lead-tin fluorophosphate (LTF) glass have been directly studied by measurement of surface enhanced second harmonic generation and third harmonic generation. The three photon excitation fluorescence is also observed. Based on these results, the large nonlinearities of the acridine LTF system which is a new nonlinear optical material are experimentally demonstrated.

  16. Silver nanoparticles enhanced luminescence properties of Er3+ doped tellurite glasses: Effect of heat treatment

    NASA Astrophysics Data System (ADS)

    Fares, Hssen; Elhouichet, Habib; Gelloz, Bernard; Frid, Mokhtar

    2014-09-01

    Tellurite glasses doped Er3+ ions and containing Silver nanoparticles (Ag NPs) are prepared using melt quenching technique. The nucleation and growth of Ag NPs were controlled by a thermal annealing process. The X-ray diffraction pattern shows no sharp peak indicating an amorphous nature of the glasses. The presence of Ag NPs is confirmed from transmission electron microscopy micrograph. Absorption spectra show typical surface plasmon resonance (SPR) band of Ag NPs within the 510-550 nm range in addition to the distinctive absorption peaks of Er3+ ions. The Judd-Ofelt (J-O) intensity parameters, oscillator strengths, spontaneous transition probabilities, branching ratios, and radiative lifetimes were successfully calculated based on the experimental absorption spectrum and the J-O theory. It was found that the presence of silver NPs nucleated and grown during the heat annealing process improves both of the photoluminescence (PL) intensity and the PL lifetime relative to the 4I13/2 ? 4I15/2 transition. Optimum PL enhancement was obtained after 10 h of heat-treatment. Such enhancements are mainly attributed to the strong local electric field induced by SPR of silver NPs and also to energy transfer from the surface of silver NPs to Er3+ ions, whereas the quenching is ascribed to the energy transfer from Er3+ ions to silver NPs. Using the Mc Cumber method, absorption cross-section, calculated emission cross-section, and gain cross-section for the 4I13/2 ? 4I15/2 transition were determined and compared for the doped and co-doped glasses. The present results indicate that the glass heat-treated for 10 h has good prospect as a gain medium applied for 1.53 ?m band broad and high-gain erbium-doped fiber amplifiers.

  17. White emission materials from glass doped with rare Earth ions: A review

    NASA Astrophysics Data System (ADS)

    Yasaka, P.; Kaewkhao, J.

    2016-03-01

    Solid State Lighting (SSL) based devices are predicted to play a crucial role in the coming years. Development of W-LED, which have an edge over traditional lighting sources due to their compact size, higher reliability, shock resistance, interesting design possibilities, higher transparency and an extremely long lifetime. Over the fifteen trivalent lanthanide ions, Dy3+ ions doped glasses are most appropriate for white light generation because of the fact that it exhibits two intense emission bands corresponds to the 4F9/2→6H15/2 (magnetic dipole) and 4F9/2→6H13/2 (electric dipole) transitions at around 480-500 nm and 580-600 nm pertaining to blue and yellow regions respectively. In this work, the developments of Dy3+ doped in several glass structures for white emitting materials application have reviewed. Properties of Dy3+ doped in glasses were discussed for use as a solid state lighting materials application.

  18. Influence of high magnetic field on the luminescence of Eu{sup 3+}-doped glass ceramics

    SciTech Connect

    Jiang, Wei; Chen, Weibo; Chen, Ping; Xu, Beibei; Zheng, Shuhong; Guo, Qiangbing; Liu, Xiaofeng E-mail: qjr@zju.edu.cn; Zhang, Junpei; Han, Junbo; Qiu, Jianrong E-mail: qjr@zju.edu.cn

    2014-09-28

    Rare earth (RE) doped materials have been widely exploited as the intriguing electronic configuration of RE ions offers diverse functionalities from optics to magnetism. However, the coupling of magnetism with photoluminescence (PL) in such materials has been rarely reported in spite of its fundamental significance. In the present paper, the effect of high pulsed magnetic field on the photoluminescence intensity of Eu{sup 3+}-doped nano-glass-ceramics has been investigated. In our experiment, Eu-doped oxyfluoride glass and glass ceramic were prepared by the conventional melt-quenching process and controlled heat treatment. The results demonstrate that the integrated PL intensity of Eu{sup 3+} decreases with the enhancement of magnetic field, which can be interpreted in terms of cooperation effect of Zeeman splitting and magnetic field induced change in site symmetry. Furthermore, as a result of Zeeman splitting, both blue and red shift in the emission peaks of Eu{sup 3+} can be observed, and this effect becomes more prominent with the increase of magnetic field. Possible mechanisms associated with the observed magneto-optical behaviors are suggested. The results of the present paper may open a new gate for modulation of luminescence by magnetic field and remote optical detection of magnetic field.

  19. Active waveguides by low-fluence carbon implantation in Nd3+-doped fluorophosphate glasses

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Xiao; Luo, Zhe-Yuan; Li, Yu-Wen; Chen, Meng; Xu, Jun; Fu, Li-Li; Yu, Ke-Han; Zheng, Rui-Lin; Zhou, Zhi-Guang; Li, Wei-Nan; Guo, Hai-Tao; Lin, She-Bao; Wei, Wei

    2016-01-01

    A planar waveguide in the Nd3+-doped fluorophosphate glass is fabricated by a 6.0 MeV C3+ ion implantation at a low-fluence of 1.0 × 1014 ions/cm2. The fluence is close to that in semiconductor industry. The dark mode spectra are recorded by a model 2010 prism coupler. The energy losses during the implantation process and the refractive index profile of the waveguide are simulated by the SRIM 2010 code and the reflectivity calculation method (RCM), respectively. The near-field light intensity profile and the propagation loss of the waveguide are measured by an end-face coupling system. The two-dimensional (2D) modal profile of transverse electric (TE) mode for the fabricated waveguide is calculated by the finite difference beam propagation method (FD-BPM). The results of microluminescence and optical absorption reveal that the spectroscopic characteristics of the Nd3+-doped fluorophosphate glass are nearly unaffected by the carbon ion implantation process. This work suggests that the carbon-implanted Nd3+-doped fluorophosphate glass waveguide is a promising candidate for integrated active devices.

  20. Laser performance at 1064 nm in Nd3+ doped oxi-tellurite glasses

    NASA Astrophysics Data System (ADS)

    Bell, Maria Jose; Anjos, Virglio; Moreira, Lyane; Falci, Rodrigo; Kassab, Luciana; Silva, D.; Doualan, Jean Louis; Camy, Patrice; Moncorge, Richard

    2015-03-01

    The search for Nd3+ doped new solid-state laser hosts having specific thermo-mechanical and optical properties is very active. Among tellurites, the TeO2-ZnO glass combines good mechanical stability, chemical durability, high linear and nonlinear refractive indices, low phonon energies (~750 cm-1) and a wide transmission window (0.4-6 ?m). Their high nonlinear optical properties can be used for the development of Kerr-lens mode-locked subpicosecond lasers. The present work concentrates on the luminescence properties and the laser performance of a TeO2-ZnO tellurite glasses doped with Nd3+. True continuous-wave laser action is achieved by pumping the sample with a CW Ti:Sapphire laser inside a standard two-mirror laser cavity. A low laser threshold of 8 mW and a laser slope efficiency of 21% could be obtained for an output coupler transmission of 2.7%, which is an encouraging improvement compared to what was reported in the past with other Nd-doped tellurite bulk glasses. Authors acknowledge the support of agencies CAPES, FAPEMIG National Institute of Photonics (INCT Project/CNPQ) and COFECUB.

  1. Fabrication of uniformly dispersed nanoparticle-doped chalcogenide glass

    NASA Astrophysics Data System (ADS)

    Lu, Chao; Almeida, Juliana M. P.; Yao, Nan; Arnold, Craig

    2014-12-01

    The dispersion of metallic nanoparticles within a chalcogenide glass matrix has the potential for many important applications in active and passive optical materials. However, the challenge of particle agglomeration, which can occur during traditional thin film processing, leads to materials with poor performance. Here, we report on the preparation of a uniformly dispersed Ag-nanoparticle (Ag NP)/chalcogenide glass heterogeneous material prepared through a combined laser- and solution-based process. Laser ablation of bulk silver is performed directly within an arsenic sulfide/propylamine solution resulting in the formation of Ag NPs in solution with an average particle size of less than 15 nm as determined by dynamic light scattering. The prepared solutions are fabricated into thin films using standard coating processes and are then analyzed using energy-dispersive X-ray spectroscopy and transmission electron microscopy to investigate the particle shape and size distribution. By calculating the nearest neighbor index and standard normal deviate of the nanoparticle locations inside the films, we verify that a uniformly dispersed distribution is achieved through this process.

  2. Optical and luminescent properties of Sm3+ doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Sasikala, T.; Rama Moorthy, L.; Mohan Babu, A.

    2013-03-01

    Glasses with chemical composition of (62-x) TeO2 + 25 ZnO + 8 K2O + 5 CaO + x Sm2O3 (TZKCSmx; x = 0.1, 0.5, 1.0, 1.5 mol%) were prepared by melt quenching technique. The absorption spectrum was recorded in the UV-visible and NIR regions. The oscillator strengths of absorption bands were obtained by measuring the area under the bands. Judd-Ofelt analysis has been carried out to estimate the host dependent J-O intensity ?? (? = 2, 4, 6) parameters by least squares fitting approach. Photoluminescence spectra recorded in the visible region revealed intense green, orange and red emission bands in all the glasses, corresponding to the 4G?6H, 4G?6H and 4G?6H transitions respectively. From the emission spectra and J-O intensity parameters, various radiative parameters were calculated from the excited 4G to the lower lying 6 state decrease with the increase of the Sm3+ ions concentration. The energy transfer mechanism that leads to the quenching of 4G state lifetime has been discussed. Inokuti-Hirayama (I-H) model was used to evaluate various energy transfer parameters, which are the qualitative indicators for the interaction among Sm3+ ions.

  3. Fabrication of uniformly dispersed nanoparticle-doped chalcogenide glass

    SciTech Connect

    Lu, Chao; Arnold, Craig; Almeida, Juliana M. P.; Yao, Nan

    2014-12-29

    The dispersion of metallic nanoparticles within a chalcogenide glass matrix has the potential for many important applications in active and passive optical materials. However, the challenge of particle agglomeration, which can occur during traditional thin film processing, leads to materials with poor performance. Here, we report on the preparation of a uniformly dispersed Ag-nanoparticle (Ag NP)/chalcogenide glass heterogeneous material prepared through a combined laser- and solution-based process. Laser ablation of bulk silver is performed directly within an arsenic sulfide/propylamine solution resulting in the formation of Ag NPs in solution with an average particle size of less than 15 nm as determined by dynamic light scattering. The prepared solutions are fabricated into thin films using standard coating processes and are then analyzed using energy-dispersive X-ray spectroscopy and transmission electron microscopy to investigate the particle shape and size distribution. By calculating the nearest neighbor index and standard normal deviate of the nanoparticle locations inside the films, we verify that a uniformly dispersed distribution is achieved through this process.

  4. Spectroscopic characteristics of chromium-doped mullite glass-ceramics

    SciTech Connect

    Wojtowicz, A.J.; Meng, W.; Lempicki, A.; Beall, G.H.; Hall, D.W.

    1988-06-01

    The chromium (3+) ion has been widely used as an optical activator in solid-state, tunable laser materials. High octahedral field-stabilization energy and resistance against both oxidation and reduction minimize the dependence of chromium (3+) on the solid-state host matrix. However, the high sensitivity of electronic structure on crystal field strength makes the appropriate choice of host the condition for success. Characteristics of chromium-doped mullite ceramics are discussed with reference to possible laser applications. Dominant features are attributed to large and inherent spectroscopic inhomogeneity of mullite. The spectroscopic data are analyzed using a generalized McCumber theory. The peak-stimulated emission cross section is 0.54 x 10 to the -20 sq cm. This together with preliminary single-pass measurements, indicate that gain for mullite is about 2.6 times smaller than gain for alexandrite.

  5. Structure and properties of strontium-doped phosphate-based glasses

    PubMed Central

    Abou Neel, Ensanya A.; Chrzanowski, Wojciech; Pickup, David M.; O'Dell, Luke A.; Mordan, Nicola J.; Newport, Robert J.; Smith, Mark E.; Knowles, Jonathan C.

    2008-01-01

    Owing to similarity in both ionic size and polarity, strontium (Sr2+) is known to behave in a comparable way to calcium (Ca2+), and its role in bone metabolism has been well documented as both anti-resorptive and bone forming. In this study, novel quaternary strontium-doped phosphate-based glasses, containing 1, 3 and 5?mol% SrO, were synthesized and characterized. 31P magic angle spinning (MAS) nuclear magnetic resonance results showed that, as the Sr2+ content is increased in the glasses, there is a slight increase in disproportionation of Q2 phosphorus environments into Q1 and Q3 environments. Moreover, shortening and strengthening of the phosphorus to bridging oxygen distance occurred as obtained from FTIR. The general broadening of the spectral features with Sr2+ content is most probably due to the increased variation of the phosphatecation bonding interactions caused by the introduction of the third cation. This increased disorder may be the cause of the increased degradation of the Sr-containing glasses relative to the Sr-free glass. As confirmed from elemental analysis, all Sr-containing glasses showed higher Na2O than expected and this also could be accounted for by the higher degradation of these glasses compared with Sr-free glasses. Measurements of surface free energy (SFE) showed that incorporation of strontium had no effect on SFE, and samples had relatively higher fractional polarity, which is not expected to promote high cell activity. From viability studies, however, the incorporation of Sr2+ showed better cellular response than Sr2+-free glasses, but still lower than the positive control. This unfavourable cellular response could be due to the high degradation nature of these glasses and not due to the presence of Sr2+. PMID:18826914

  6. Effect of silver nanoparticles on spectroscopic properties of Er3+ doped phosphate glass

    NASA Astrophysics Data System (ADS)

    Soltani, I.; Hraiech, S.; Horchani-Naifer, K.; Elhouichet, H.; Frid, M.

    2015-08-01

    The Er3+ doped zinc phosphate glasses containing Ag nanoparticles (Ag NPS) were synthesized from high purity raw materials by melt quenching method. The transmission electron microscopic (TEM) images confirm the presence of spherical silver NPs having average diameter in the range of 20-40 nm. A wide absorption band peaking at about 403 nm was observed due to surface plasmon resonance (SPR) of Ag NPs. The Judd-Ofelt (JO) parameters ?2, ?4 and ?6, were determined for Er3+ ions using the absorption bands. The quality factor was determined and is found to be in the same order (0.52-1.12) than other host glasses. The enhanced photoluminescence (PL) intensity with Ag adding was attributed to the increased local field on the Er3+ ions located in the proximity of the NPs and/or the energy transfer from the metallic Ag NPs to the Er3+ ions. The absorption and emission cross-sections are calculated and determined for the 4I13/2 ? 4I15/2 transition and then compared with other reported doped glasses. The phosphate glasses are promising gain media for developing the solid-state 1.53 ?m optical amplifiers.

  7. Optical transitions and visible upconversion in Er3+ doped niobic tellurite glass

    NASA Astrophysics Data System (ADS)

    Lin, Hai; Meredith, Gerald; Jiang, Shibin; Peng, Xiang; Luo, Tao; Peyghambarian, Nasser; Pun, Edwin Yue-Bun

    2003-01-01

    Er3+ doped Nb2O5-TeO2 (NT) glass suitable for developing optical fiber laser and amplifier has been fabricated and characterized. Intense and broad 1.53 ?m infrared fluorescence and visible upconversion luminescence were observed under 975 nm diode laser and 798 nm laser excitation. For 1.53 ?m emission band, the full width at half-maximum is 51 nm, the fluorescence lifetime is 2.6 ms, and the quantum efficiency is 100%. The maximum emission cross section is 8.5210-21 cm2 at 1.532 ?m, and is higher than the values in silicon and phosphate glasses. Under 798 nm excitation, efficient 531, 553, and 670 nm upconversion emissions are due to two-photon absorption processes. The "standardized" efficiency for the green upconversion light is 9.510-4, and this value is comparable to that reported for Er3+/Yb3+ codoped fluoride glasses. Intense visible upconversion fluorescence in Er3+ doped NT glass can be used in color display, undersea communication, and infrared sensor.

  8. Ni(2+) doped glass ceramic fiber fabricated by melt-in-tube method and successive heat treatment.

    PubMed

    Fang, Zaijin; Zheng, Shupei; Peng, Wencai; Zhang, Hang; Ma, Zhijun; Dong, Guoping; Zhou, Shifeng; Chen, Danping; Qiu, Jianrong

    2015-11-01

    Glass ceramic fibers containing Ni(2+) doped LiGa(5)O(8) nanocrystals were fabricated by a melt-in-tube method and successive heat treatment. Fiber precursors were prepared by drawing at high temperature where fiber core glass was melted while fiber clad glass was softened. After heat treatment, LiGa(5)O(8) nanocrystals were precipitated in the fiber core. Excited by 980 nm laser, efficient broadband near-infrared emission was observed in the glass ceramic fiber compared to that of precursor fiber. The melt-in-tube method can realize controllable crystallization and is suitable for fabrication of novel glass ceramic fibers. The Ni(2+)-doped glass ceramic fiber is promising for broadband optical amplification. PMID:26561096

  9. Optical, elastic properties and DTA of TNZP host tellurite glasses doped with Er3+ ions

    NASA Astrophysics Data System (ADS)

    Yousef, El Sayed; Elokr, M. M.; AbouDeif, Y. M.

    2016-03-01

    Novel quaternary tellurite glasses within the composition 75TeO2-10Nb2O5-10ZnO-5PbO (TNZP) doped with the following Er3+ concentrations: 2500, 3750, 5000, 6250, 7500 and 8750 ppm have been prepared by using conventional melt quenching method. The thermal parameters, such as the glass transition temperature (Tg), crystallization temperature (Tc) and thermal stability (ΔТ) were determined. It is described that this system shows a stable glass formation, high thermal stability and low tendency crystallization. The linear refractive index, n, the optical energy gap, Eg, the nonlinear refractive index, n2, two photon absorption TPA, third order susceptibility, χ(3), of prepared glasses have been determined. Moreover elastic properties like longitudinal (λ), shear (μ), Bulk (β) and Young's (Y) moduli, Poisson's ratio, Debye temperature, and the microhardness of the glasses were evaluated by measuring both longitudinal and shear velocities using the pulse-echo overlap technique at 5 MHz. The present glasses is a promising candidate for optical application.

  10. NIR emission studies and dielectric properties of Er(3+)-doped multicomponent tellurite glasses.

    PubMed

    Sajna, M S; Thomas, Sunil; Jayakrishnan, C; Joseph, Cyriac; Biju, P R; Unnikrishnan, N V

    2016-05-15

    Multicomponent tellurite glasses containing altered concentrations of Er2O3 (ranging from 0 to 1mol%) were prepared by the standard melt quenching technique. Investigations through energy dispersive X-ray spectroscopy (EDS), Raman scattering spectroscopy, Fourier transform infrared (FTIR) spectroscopy, near-infrared (NIR) emission studies and dielectric measurement techniques were done to probe their compositional, structural, spectroscopic and dielectric characteristics. The broad emission together with the high values of the effective linewidth (~63nm), stimulated emission cross-section (9.67×10(-21)cm(2)) and lifetime (2.56ms) of (4)I13/2 level for 0.5mol% of Er(3+) makes these glasses attractive for broadband amplifiers. From the measured capacitance and dissipation factor, the relative permittivity, dielectric loss and the conductivity were computed; which furnish the dielectric nature of the multicomponent tellurite glasses that depend on the applied frequency. Assuming the ideal Debye behavior as substantiated by Cole-Cole plot, an examination of the real and imaginary parts of impedance was performed. The power-law and Cole-Cole parameters were resolved for all the glass samples. From the assessment of the emission analysis and dielectric properties of the glass samples, it was obvious that the Er(3+) ion concentration had played a vital role in tuning the optical and dielectric properties and the 0.5mol% of Er(3+) -doped glass was confirmed as the optimum composition. PMID:26967514

  11. Unusual luminescence quenching and reviving behavior of Bi-doped germanate glasses.

    PubMed

    Xu, Beibei; Zhou, Shifeng; Guan, Miaojia; Tan, Dezhi; Teng, Yu; Zhou, Jiajia; Ma, Zhijun; Hong, Zhanglian; Qiu, Jianrong

    2011-11-01

    Here for the first time, we report an unusual annealing temperature dependent near-infrared (NIR) luminescence quenching and reviving behavior in Bi-doped MgO-Al?O?-GeO? glasses. Systematic characterizations of the samples by using differential thermal analysis (DTA), photoluminescence and absorption spectra, X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate that this phenomenon is associated with the reversible reaction of Bi? and Bi? initiated by the change of local glass structure. Excitingly, wavelength tunable luminescence is also observed and it can be ascribed to selective excitation of active Bi? center in different sites. These results not only open a new way for controlling luminescence properties of main group elements in glass but also provide great value for improving practical active-fiber drawing process. PMID:22109220

  12. EPR and optical absorption studies on manganese ion doped in mixed alkali cadmium phosphate glasses

    NASA Astrophysics Data System (ADS)

    Giridhar, G.; Rangacharyulu, M.; Ravikumar, R. V. S. S. N.; Sambasiva Rao, P.

    2009-07-01

    Electron paramagnetic resonance (EPR) spectra of Mn(II) ions in cadmium phosphate glasses are presented with mixed alkali variation as xLi2O + (20 - x) Na2O + 20 CdO + 59.5 P2O5 + 0.5 MnO glass system with 5 <= x <= 15 mol%. The EPR spectra of Mn(II) ions doped samples exhibit a sextet centered at g = 20. The optical absorption spectrum at room temperature shows three bands for Mn(II) ions in octahedral symmetry. The crystal field (Dq) and Racah parameters (B and C) are evaluated. From EPR and optical spectral studies reveals the nature of the bonding is dominantly ionic and its site symmetry is octahedral. At equal composition of alkali content, i.e. for x = 10 the glass system shows the mixed alkali effect.

  13. Tm3+-doped ion-exchanged aluminum germanate glass waveguide for S-band amplification

    NASA Astrophysics Data System (ADS)

    Yang, D. L.; Pun, E. Y. B.; Lin, H.

    2009-10-01

    K+-Na+ ion-exchanged channel waveguide amplifiers have been fabricated in Tm3+-doped acid-resistant aluminum germanate glasses. The optical and relative gains of a 3.15-cm-long waveguide channel were achieved to be 4.05 and 2.29 dB at 1.482 ?m wavelength under 110 mW 793 nm laser excitation, respectively. After compensating the propagation loss, an internal gain of 1.50 dB and a remarkable gain coefficient of 0.48 dB/cm were obtained, which reveals a definite S-band signal amplification in the low phonon energy glass waveguide. As an expectation, UV-radiation-sensitive glass waveguide should promote the developments of gain-flatten S-band waveguide amplifiers, infrared UV-writing grating waveguide lasers, and compact multifunctional integrated optical devices.

  14. Origins of the broadening in 1.5?m emission of Er3+-doped glasses

    NASA Astrophysics Data System (ADS)

    Dousti, M. Reza

    2015-11-01

    The broadband emission (4I13/2?4I15/2) of the Er3+-doped glasses has been always an attractive topic of research due to its explicit role in the progress of optical fibers science and technology. Few characteristics, such as the full-width at half-maximum, shape and excited state lifetime of this band are determinant parameters to obtain practically appropriate materials for high-tech applications. In this work, the broadening of the latter near-infrared emission of erbium ions, centered around 1.53?m in C-band region, is briefly discussed as a function of the host glass, glass modifiers, temperature and thickness of the sample, excitation power and energy, as well as the concentration of the dopant.

  15. Fluorescence properties of rare-earth doped sol-gel silica glasses

    NASA Astrophysics Data System (ADS)

    Stone, Brandon Thomas

    Rare earth doped silica glasses find numerous applications ranging from fiber amplifiers for optical communications to high power lasers for inertial confinement fusion research. The performance of rare earth doped optical devices would be improved by better understanding of relationships among glass structure, composition and dopant ion optical properties. The specific problem of rare earth ion clustering limits the efficiency of rare earth optical devices by limiting optimal rare earth ion concentrations. The fluorescence properties of rare earth ions were studied in sol-gel silica in order to determine the mechanism of rare earth ion clustering and evaluate synthesis procedures designed to prevent clustering. Fluorescence line narrowing measurements were used to identify rare earth clustering. While aluminum co-doping in rare earth doped silica has been found to eliminate rare earth ion clusters, it has also been found to increase the residual hydroxyl content and hydroxyl quenching. The use of an alternate aluminum precursor expected to reduce the hydroxyl content in sol-gel silica and the use of other co-dopant ions to reduce rare earth ion clustering were considered. Hydroxyl quenching due to the large residual hydroxyl content in sol-gel silica lowers optical efficiencies through non-radiative decay of ions in excited states. Excited state lifetime measurements were used to qualitatively assess the hydroxyl content of rare earth doped sol-gel silica with different compositions and prepared with different procedures. Fluorinated dopant ion precursors were used to produce in situ dehydroxylation in rare earth doped sol-gel silica. Additionally, rare earth doped hybrid organic/inorganic gels were prepared in an effort to reduce the hydroxyl content of the final silica glass. The influence of these synthesis schemes on rare earth ion clustering was also determined. The effects of energy transfer between rare earth ions in sol-gel silica were examined with lifetime, fluorescence, and upconversion measurements. Rare earth ion clustering was expected to have a beneficial effect on upconversion. Green and red upconversion fluorescence was detected, and models of the upconversion processes were developed.

  16. Preparation and characterization of silver-doped nanobioactive glass particles and their in vitro behaviour for biomedical applications.

    PubMed

    Prabhu, Muthusamy; Kavitha, Kandiah; Suriyaprabha, Rangaraj; Manivasakan, Palanisamy; Rajendran, Venkatachalam; Kulandaivelu, Palanisami

    2013-08-01

    In this study, silver-doped silica- and phosphate-based nanobioactive glass compositions (58SiO2-(33- x)CaO-9P2O5-xAg2O) (x = 0, 0.5, 1, 2 and 3 mol%) were synthesised by a simple and cost-effective sol-gel method. The prepared samples were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and energy-dispersive X-ray fluorescence spectrometer studies. All the compositions of the glass samples revealed amorphous phase with spherical morphology and a particle size less than 100 nm. The prepared glass samples reveal the specific surface area in the range of 55.31-90.69 m2 g(-1). The bioactivity of glass samples was confirmed through the formation of the hydroxyapatite layer on glass surfaces during in vitro studies in which silver doped glasses (2 and 3 mol%) showed better bioactivity. A better biocompatibility was achieved in human gastric adenocarcinoma cell line in case of silver-free glass sample while comparing the biological behaviour of Ag2O-doped glasses. Further, the Ag2O-doped nanobioactive glasses revealed significant antibacterial activity against Staphylococcus aureus and Escherichia coli. Ag2O substitutions showed better in vitro bioactivity and remained slightly toxic to human cells at a concentration of 100 microg mL(-1). Silver-doped nanobioactive glass shows good antimicrobial property as well as no significant toxic for implant applications. PMID:23882760

  17. Efficient and long-lived Zeeman-sublevel atomic population storage in an erbium-doped glass fiber

    NASA Astrophysics Data System (ADS)

    Saglamyurek, Erhan; Lutz, Thomas; Veissier, Lucile; Hedges, Morgan P.; Thiel, Charles W.; Cone, Rufus L.; Tittel, Wolfgang

    2015-12-01

    Long-lived population storage in optically pumped levels of rare-earth ions doped into solids, referred to as persistent spectral hole burning, is of significant fundamental and technological interest. However, the demonstration of deep and persistent holes in rare-earth ion doped amorphous hosts, e.g., glasses, has remained an open challenge for many decades—a fact that motivates our work towards a better understanding of the interaction between impurities and vibrational modes in glasses. Here we report the observation and detailed characterization of such holes in an erbium-doped silica glass fiber cooled to below 1 K. We demonstrate population storage in electronic Zeeman sublevels of the erbium ground state with lifetimes up to 30 seconds and 80% spin polarization. In addition to its fundamental aspect, our investigation reveals a potential technological application of rare-earth ion doped amorphous materials, including at telecommunication wavelength.

  18. Synthesis, characterization and processing of active rare earth-doped chalcohalide glasses

    NASA Astrophysics Data System (ADS)

    Debari, Roberto Mauro

    Applications for infrared-transmitting non-oxide glass fibers span a broad range of topics. They can be used in the military, the medical field, telecommunications, and even in agriculture. Rare earth ions are used as dopants in these glasses in order to stimulate emissions in the infrared spectral region. In order to extend the host glass transmission further into the infrared, selenium atoms were substituted for sulfur in the established Ge-S-I chalcohalide glass system and the fundamental properties of these latter glasses were explored. Over 30 different compositions in the Ge-Se-I glass system were investigated as to their thermal and optical properties. The resulting optimum host with a composition of Ge15Se80I5 has a broad transmission range from 0.7 mum to 17.0 mum and a high working range over 145C. The host glass also exhibited a Tg of 125C, making rotational casting of a cladding tube for rod-and-tube fiberization a possibility. The base glass was doped with 1000 to 4000 ppm/wt of erbium, dysprosium, or neodymium. When doped with Er3+-ions, absorptions at 1.54 mum and 3.42 mum were observed. Nd3+-doping resulted in an absorption peak near 4.24 mum and Dy3+ ions caused absorption at 1.30 mum. Fluorescence emissions were found for neodymium at 1.396 mum with a FWHM of 74 nm, and for dysprosium at 1.145 mum with a FWHM of 75 nm, at 1.360 mum with a FWHM of 98 rim and at 1.674 mum with a FWHM of 60 nm. High optical quality tubes of the host glass could be formed using rotational casting in silica ampoules. Glass tubes, 4 to 6 cm long with a 1 cm outer diameter and a tailored inner-hole diameter ranging from 0.4 to 0.6 cm could be synthesized by this process with excellent dimensional tolerances around the circumference as well as along the length. A preform of this size provided 25 continuous meters of unclad fiber with diameters ranging from 140 to 200 mum. A UV-curable acrylate cladding was applied via an external coating cup. An x-ray analysis of the resulting fiber verified the constituents of the fiber. Due to tradeoffs between thermal properties, optical properties and rare earth solubility, the Ge-Se-I glass system must still be optimized prior to use as an active fiber device. Nevertheless, the viability of this host system has been demonstrated in this investigation. Some very promising advantages to adding halides to chalcogenide glass systems have been confirmed, including the tailoring of glass transition temperatures, enhancement of rare earth solubility, expanded fluorescence emissions in the IR, and suppression of some impurity absorption bands. Also, the potential for rod-and-tube fiberization utilizing the rotational casting method for tube synthesis has been established along with its resulting pristine core-clad interface. This research provides a foundation for active fiber device applications in the 2 to 10 mum spectral region.

  19. Chalcogenide glasses for infrared applications: New synthesis routes and rare earth doping

    NASA Astrophysics Data System (ADS)

    Hubert, Mathieu

    Chalcogenide glasses and glass-ceramics present a high interest for the production of thermal imaging lenses transparent in the 3--5 microm and 8--12 microm windows. However, chalcogenide glasses are conventionally synthesized utilizing expensive and single use silica ampoules sealed under vacuum. The present work addresses the development of innovative synthesis methods for chalcogenide glasses that can present an alternative to the silica tube route. The first approach assessed by melting the raw starting elements in reusable silica containers appears inadequate for synthesis of glasses from the system Ge-Ga-Se. The second synthesis approach consists of the preparation of amorphous chalcogenide powders by ball milling of raw elements (mechanosynthesis) followed by consolidation of the as-prepared powders. Hot Uniaxial Pressing is suitable for sintering of powders with compositions stable against crystallization but uncontrolled crystallization occurs for the unstable compositions. In contrast, consolidation through Spark Plasma Sintering (SPS) allows production of bulk glasses with large dimensions in a short duration and at relatively low temperatures. Moreover, increased SPS treatment duration yields infrared transparent glass-ceramics with enhanced mechanical properties. This innovative synthesis method combining mechanosynthesis and SPS has been patented in the framework if this study. The controlled etching of 80GeSe2-20Ga2Se 3 glass-ceramics in acid solution yields nanoporous materials with enhanced surface area. The porous layer created on the surface of the glass-ceramic plays the role of anti-reflection coating and increases the optical transmission in the infrared range by 10%. These materials present potential for the production of sensors with increased sensitivity. The influence of indium and lead addition on the thermal and optical properties of the 80GeSe2-20Ga2Se3 glass is also assessed. Increased In or Pb contents tend to decrease the Tg and shift the optical band gap toward higher wavelengths. A systematic ceramization study emphasizes the difficulty of controlling the crystallization for glasses in the systems GeSe2-Ga2Se3-In2Se 3 and GeSe2-Ga2Se3-PbSe. No crystallization of the In2Se3 and PbSe crystalline phase was obtained. Finally, the possibility of producing rare-earth doped 80GeSe2 -20Ga2Se3 glass-ceramics transparent in the infrared region up to 16 microm is demonstrated. Enhanced photoluminescence intensity and reduced radiative lifetimes are observed with increased crystallinity in these materials.

  20. Spectroscopic properties of Ho3+, Tm3+, and Ho3+/Tm3+ doped tellurite glasses for fiber laser applications

    NASA Astrophysics Data System (ADS)

    Seshadri, M.; Ferencz Junior, J. A. P.; Ratnakaram, Y. C.; Barbosa, L. C.

    2014-03-01

    Several papers were reported on spectroscopic properties of rare earth doped different host glasses. A complete knowledge of fluorescence properties of rare earth ions in laser materials is necessary to achieve efficient, compact and cheap sources of laser radiation for NIR and mid-IR region. Tellurite glasses are potentially useful for generation of NIR and mid-IR laser radiation due to its special features such as lowest phonon energy (750 cm-1) among oxide glasses, reasonably wide transmission region (0.35 - 5?m), good glass stability, good rare earth ion solubility, high linear and non-linear refractive index. In the present work, authors prepared Ho3+ and Tm3+ singly doped and Ho3+/Tm3+ co-doped tellurite glasses using conventional melt-quenching method. Spectroscopic measurements and analysis of energy transfer process in Ho3+, Tm3+ and Ho3+ /Tm3+ co-doped glasses pumped with 785nm and 451 nm excitation wavelengths have been performed. There are some spectroscopic properties which are important in understanding and modeling of rare earth doped laser materials. Using Judd-Ofelt theory, radiative transition rates (Arad), radiative lifetimes (?R) and branching ratios (?) were estimated for certain excited states of Ho3+ and Tm3+ doped tellurite glasses. The emission cross-sections and gain coefficients have been determined from the absorption spectra of Ho3+ and Tm3+ ions in tellurite glasses. The energy transfer process such as ion cross-relaxation, Tm3+-Ho3+ energy transfer and energy transfer upconversion were studied and identified to specific candidate for laser operation.

  1. Correlation of ion dynamics and structure of superionic tellurite glasses

    SciTech Connect

    Dutta, D.; Ghosh, A.

    2008-01-28

    Ion dynamics and structure of a series of superionic AgI-doped silver tellurite glasses have been investigated in this paper. The composition dependence of the dc conductivity and the activation energy of these glasses has been compared with those of AgI-doped silver phosphate and borate glasses. We have observed that the conductivity increases and the activation energy decreases with increase of AgI content and that the tellurite glasses have higher conductivity than those for phosphate or borate glasses. We have analyzed the ac electrical data in the framework of the power law and the electric modulus formalisms. We have established a correlation between the crossover rate of the mobile silver ions and the rearrangement of the structural units in tellurite glasses. The scaling of the conductivity spectra has been used to interpret the temperature and composition dependence of the relaxation dynamics. Analysis of the dielectric relaxation in the framework of modulus formalism indicates an increase in the ion-ion cooperation in the glass compositions with increasing AgI content.

  2. The chemical durability of glass and graphite-glass composite doped with cesium oxide

    NASA Astrophysics Data System (ADS)

    Hamodi, Nasir H.; Abram, Timothy J.; Lowe, Tristan; Cernik, Robert J.; Lpez-Honorato, Eddie

    2013-01-01

    The role of temperature in determining the chemical stability of a waste form, as well as its leach rate, is very complex. This is because the dissolution kinetics is dependent both on temperature and possibility of different rate-controlling mechanisms that appear at different temperature regions. The chemical durability of Alumina-Borosilicate Glass (ABG) and Glass-Graphite Composite (GGC), bearing Tristructural Isotropic (TRISO) fuel particles impregnated with cesium oxide, were compared using a static leach test. The purpose of this study is to examine the chemical durability of glass-graphite composite to encapsulate coated fuel particles, and as a possible alternative for recycling of irradiated graphite. The test was based on the ASTM C1220-98 methodology, where the leaching condition was set at a temperature varying from 298 K to 363 K for 28 days. The release of cesium from ABG was in the permissible limit and followed the Arrhenius's law of a surface controlled reaction; its activation energy (Ea) was 65.6 0.5 kJ/mol. Similar values of Ea were obtained for Boron (64.3 0.5) and Silicon (69.6 0.5 kJ/mol) as the main glass network formers. In contrast, the dissolution mechanism of cesium from GGC was a rapid release, with increasing temperature, and the activation energy of Cs (91.0 5 kJ/mol) did not follow any model related to carbon kinetic dissolution in water. Microstructure analysis confirmed the formation of Crystobalite SiO2 as a gel layer and Cs+1 valence state on the ABG surface.

  3. Influence of Nd3+ ions on TL characteristics of Li2O-MO-B2O3 (MO = ZnO, CaO, CdO) glass system

    NASA Astrophysics Data System (ADS)

    Anjaiah, J.; Laxmikanth, C.; Lyobha, Cephas John; Veeraiah, N.; Kistaiah, P.

    2015-02-01

    Thermoluminescence (TL) characteristics of X-ray irradiated pure and doped with Nd3+ ions glasses have been studied in the temperature range 303-573 K; all the pure glasses have exhibited single TL peak at 382, 424 and 466 K, respectively. When these glasses are doped with Nd3+ ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Nd3+-doped glasses mixed with cadmium oxide as modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that neodymium (Nd)-doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  4. Spectroscopic and radiative properties study of Nd 3+ doped cadmium-phosphate glasses

    NASA Astrophysics Data System (ADS)

    Mahmoud, K. H.

    2010-12-01

    A spectroscopic investigation is performed on Nd 3+ doped cadmium-phosphate glasses. The Judd-Ofelt analysis is applied to the glass system in order to evaluate their potential as both glass laser and amplifier materials. The phenomenological Judd-Ofelt parameters Ω(2), Ω(4), and Ω(6) are determined, their values are 4.80×10 -20, 6.18×10 -20, and 7.14×10 -20 cm -2, respectively. The quality factor for glass system is 0.86. Predicted radiative decay rates and branching ratios of transitions from Nd 3+4F 3/2 state to the 4I J manifolds are determined and analyzed. The calculated lifetime of the 4F 3/2 metastable state of Nd 3+ is 31 μs. The results showed that 4F 3/2 to 4I 11/2 transition, with fluorescence at 1056 nm, has the most potential for laser application. Photoluminescence up-conversion under excitation at 488 nm laser light exhibits three emission bands of Nd 3+ ions at 541 (green), 601 (orange), and 677 nm (red). These emission bands are assigned to 4G 7/2→ 4I 9/2, 4G 7/2→ 4I 11/2, and 4G 7/2→ 4I 13/2 transitions, respectively. Analysis of luminescence spectra enhances the use of glass system in optical displays, lasers, and optical memory devices.

  5. Structural and spectroscopic investigations on Eu 3+-doped alkali fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Marimuthu, K.; Karunakaran, R. T.; Surendra Babu, S.; Muralidharan, G.; Arumugam, S.; Jayasankar, C. K.

    2009-07-01

    Eu 3+-doped alkali fluoroborate glasses B 2O 3-XCO 3-NaF-Eu 2O 3 (where X = Li 2, Na 2, K 2, and Ca, Mg) have been prepared using the conventional melting technique and their structural and optical properties have been evaluated. The XRD pattern of the glasses confirmed the amorphous nature and the FTIR spectra reveal the presence of BO 3 and BO 4 units as their local structures along with the strong OH - groups. From the absorption spectra the bonding parameters have been calculated and confirmed that the Eu-O bonds in the studied glasses are of covalent nature. Judd-Ofelt (JO) analysis has been carried out from the emission spectra. The JO parameters have been used to calculate transition probabilities ( A), lifetime ( τR) and branching ratios ( βR) and peak stimulated emission cross-section ( σPE) for the 5D 0 → 7F J ( J = 1, 2, 3 and 4) transitions of the Eu 3+ ions. The decay from the 5D 0 level of Eu 3+ ions in the title glasses has been measured and analysed. The lifetime of the 5D 0 level is found to be shorter than the reported glasses which may be due to the presence of OH - groups.

  6. Effect of borate glass composition on its conversion to hydroxyapatite and on the proliferation of MC3T3-E1 cells.

    PubMed

    Brown, Roger F; Rahaman, Mohamed N; Dwilewicz, Agatha B; Huang, Wenhai; Day, Delbert E; Li, Yadong; Bal, B Sonny

    2009-02-01

    Glasses containing varying amounts of B(2)O(3) were prepared by partially or fully replacing the SiO(2) in silicate 45S5 bioactive glass with B(2)O(3). The effects of the B(2)O(3) content of the glass on its conversion to hydroxyapatite (HA) and on the proliferation of MC3T3-E1 cells were investigated in vitro. Conversion of the glasses to HA in dilute (20 mM) K(2)HPO(4) solution was monitored using weight loss and pH measurements. Proliferation of MC3T3-E1 cells was determined qualitatively by assay of cell density at the glass interface after incubation for 1 day and 3 days, and quantitatively by fluorescent measurements of total DNA in cultures incubated for 4 days. Higher B(2)O(3) content of the glass increased the conversion rate to HA, but also resulted in a greater inhibition of cell proliferation under static culture conditions. For a given mass of glass in the culture medium, the inhibition of cell proliferation was alleviated by using glasses with lower B(2)O(3) content, by incubating the cell cultures under dynamic rather than static conditions, or by partially converting the glass to HA prior to cell culture. PMID:18306284

  7. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration.

    PubMed

    Morais, D S; Fernandes, S; Gomes, P S; Fernandes, M H; Sampaio, P; Ferraz, M P; Santos, J D; Lopes, M A; Sooraj Hussain, N

    2015-09-01

    The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA_Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response. PMID:26391473

  8. Direct laser writing of topographic features in semiconductor-doped glass

    NASA Astrophysics Data System (ADS)

    Smuk, Andrei Y.

    2000-11-01

    Patterning of glass and silica surfaces is important for a number of modern technologies, which depend on these materials for manufacturing of both final products, such as optics, and prototypes for casting and molding. Among the fields that require glass processing on microscopic scale are optics (lenses and arrays, diffractive/holographic elements, waveguides), biotechnology (capillary electrophoresis chips and biochemical libraries) and magnetic media (landing zones for magnetic heads). Currently, standard non-laser techniques for glass surface patterning require complex multi-step processes, such as photolithography. Work carried out at Brown has shown that semiconductor- doped glasses (SDG) allow a single-step patterning process using low power continuous-wave visible lasers. SDG are composite materials, which consist of semiconductor crystallites embedded into glass matrix. In this study, borosilicate glasses doped with CdSxSe1-x nanocrystals were used. Exposure of these materials to a low-power above- the-energy gap laser beam leads to local softening, and subsequent expansion and rapid solidification of the exposed volume, resulting in a nearly spherical topographic feature on the surface. The effects of the incident power, beam configuration, and the exposure time on the formation and final parameters of the microlens were studied. Based on the numerical simulation of the temperature distribution produced by the absorbed Gaussian beam, and the ideas of viscous flow at the temperatures around the glass transition point, a model of lens formation is suggested. The light intensity distribution in the near-field of the growing lens is shown to have a significant effect on the final lens height. Fabrication of dense arrays of microlenses is shown, and the thermal and structural interactions between the neighboring lenses were also studied. Two-dimensional continuous-profile topographic features are achieved by exposure of the moving substrates to the writing beam. By controlling the translation speed and the position of the sample, predefined extended structures, such as diffractive optical elements (blazed gratings, Dammann generators, Fresnel zone plates) can be produced with resolution of ~1μm. Below-the-surface patterning is achieved due to a selective etching of laser-written structures in hydrofluoric acid. Similar selective etching technique was developed for undoped borosilicate glasses by exposure to intense visible and UV radiation.

  9. Optical studies on Eu{sup 3+} doped boro-tellurite glasses

    SciTech Connect

    Maheshvaran, K.; Marimuthu, K.

    2012-06-05

    Eu{sup 3+} doped boro-tellurite glasses with the chemical composition (39-x)B{sub 2}O{sub 3}+30TeO{sub 2}+15MgO+15K{sub 2}O +xEu{sub 2}O{sub 3} (where x = 0.01, 0.1, 1, 2 and 3 wt%) have been prepared by following conventional melt quenching technique. Spectroscopic properties of the Eu{sup 3+} doped boro-tellurite glasses have been studied by recording the optical absorption and luminescence measurements. Through the optical absorption spectra, bonding parameters ({beta}-bar, {delta}) have been calculated to identify the ionic/covalent nature of the glasses. Judd-Ofelt (JO) analysis have been carried out using the luminescence spectra. The JO parameters ({Omega}{sub {lambda}}= 2, 4 and 6) were used to calculate the radiative properties for the {sup 5}D{sub 0}{yields}{sup 7}F{sub J} (J = 1, 2, 3 and 4) emission transitions of the Eu{sup 3+} ions. The change in optical properties with the variation of Eu{sup 3+} ion concentration have been studied and discussed with similar studies.

  10. Time Evolution of Radiation-Induced Luminescence in Terbium-Doped Silicate Glass

    NASA Technical Reports Server (NTRS)

    West, Michael S.; Winfree, William P.

    1996-01-01

    A study was made on two commercially available terbium-doped silicate glasses. There is an increased interest in silicate glasses doped with rare-earth ions for use in high-energy particle detection and radiographic applications. These glasses are of interest due to the fact that they can be formed into small fiber sensors; a property that can be used to increase the spatial resolution of a detection system. Following absorption of radiation, the terbium ions become excited and then emit photons via 4f-4f electronic transitions as they relax back to the ground state. The lifetime of these transitions is on the order of milliseconds. A longer decay component lasting on the order of minutes has also been observed. While radiative transitions in the 4f shell of rare-earth ions are generally well understood by the Judd-Olfelt theory, the pr'esence of a longer luminescence decay component is not. Experimental evidence that the long decay component is due, in part, to the thermal release of trapped charge carriers will be presented. In addition, a theoretical model describing the time evolution of the radiation-induced luminescence will be presented.

  11. Fabrication and luminescence behavior of phosphate glass ceramics co-doped with Er3+ and Yb3+

    NASA Astrophysics Data System (ADS)

    Yu, Xiaochen; Duan, Li; Ni, Lei; Wang, Zhuo

    2012-08-01

    Transparent phosphate glass ceramics co-doped with Er3+ and Yb3+ in the system P2O5Li2OCaF2TiO2 were successfully synthesized by melt-quenching and subsequent heating. Formation of the nanocrystals was confirmed by X-ray powder diffraction. Judd-Ofelt analyses of Er3+ ions in the precursor glasses and glass ceramics were performed to evaluate the intensity parameters Ω2,4,6. Under 975 nm excitation, intense upconversion (UC) and infrared emission (1545 nm) were observed in the glass ceramics by efficient energy transfer from Yb3+ to Er3+. The luminescence processes were explained and the emission cross section was calculated by Fuchtbauer-Ladenburg (F-L) formula. The results confirm the potential applications of Er3+/Yb3+ co-doped glass ceramics as laser and fiber amplifier media.

  12. Optical thermometry based on luminescence behavior of Dy3+-doped transparent LaF3 glass ceramics

    NASA Astrophysics Data System (ADS)

    Bu, Y. Y.; Cheng, S. J.; Wang, X. F.; Yan, X. H.

    2015-11-01

    Dy3+-doped transparent LaF3 glass ceramics were fabricated, and its structures of resulting glass ceramics are studied by the X-ray diffraction and transmission electron microscopy. Optical temperature sensing of the resulting glass ceramics in the temperature range from 298 to 523 K is studied based on the down-conversion luminescence of Dy3+ ion. By using fluorescence intensity ratio method, the 4I15/2 and 4F9/2 of Dy3+ ions are verified as thermally coupled levels. A minimum S R = 1.16 10-4 K-1 is obtained at T = 294 K. By doping Eu3+ ion, the overall emission color of Eu3+-Dy3+ co-doped transparent glass ceramics can be tuned from white to yellow with the temperature increase through energy transfer between Eu3+ and Dy3+. Additionally, the thermal stability of the Dy3+ single-doped transparent glass ceramics becomes higher after doping Eu3+ ion.

  13. Sol-gel synthesis and in vitro bioactivity of copper and zinc-doped silicate bioactive glasses and glass-ceramics.

    PubMed

    Bejarano, Julian; Caviedes, Pablo; Palza, Humberto

    2015-04-01

    Metal doping of bioactive glasses based on ternary 60SiO2-36CaO-4P2O5 (58S) and quaternary 60SiO2-25CaO-11Na2O-4P2O5 (NaBG) mol% compositions synthesized using a sol-gel process was analyzed. In particular, the effect of incorporating 1, 5 and 10?mol% of CuO and ZnO (replacing equivalent quantities of CaO) on the texture, in vitro bioactivity, and cytocompatibility of these materials was evaluated. Our results showed that the addition of metal ions can modulate the textural property of the matrix and its crystal structure. Regarding the bioactivity, after soaking in simulated body fluid (SBF) undoped 58S and NaBG glasses developed an apatite surface layer that was reduced in the doped glasses depending on the type of metal and its concentration with Zn displaying the largest inhibitions. Both the ion release from samples and the ion adsorption from the medium depended on the type of matrix with 58S glasses showing the highest values. Pure NaBG glass was more cytocompatible to osteoblast-like cells (SaOS-2) than pure 58S glass as tested by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The incorporation of metal ions decreased the cytocompatibility of the glasses depending on their concentration and on the glass matrix doped. Our results show that by changing the glass composition and by adding Cu or Zn, bioactive materials with different textures, bioactivity and cytocompatibility can be synthesized. PMID:25760730

  14. Fluorescence and thermal stress properties of Yb3+-doped alumino silicate glasses for ultra high peak power laser applications

    NASA Astrophysics Data System (ADS)

    Tiegel, Mirko; Herrmann, Andreas; Kuhn, Stefan; Rssel, Christian; Krner, Jrg; Klpfel, Diethard; Seifert, Reinhard; Hein, Joachim; Kaluza, Malte C.

    2014-11-01

    Various alumino silicate glasses (network modifier ions: Li+, Mg2+, Zn2+ and/or La3+) doped with 1? ?1020 Yb3+?cm-3 (about 0.2?mol% Yb2O3) were prepared. The glasses were studied with respect to their thermo-mechanical and fluorescence properties. Huge differences are found for the coefficients of thermal expansion which determine the thermal shock resistance of the material and hence are required for ultra-high power laser applications. Here, zinc and magnesium alumino silicate glasses show the lowest values. The fluorescence lifetimes of the glasses increase with decreasing average atomic weight of the glass composition (685-1020?s). All glasses show broad and smooth emission spectra with little variations due to compositional changes. Mixed lithium zinc or lithium magnesium alumino silicate glasses could be promising new laser materials especially with respect to ultra-high peak power systems or applications with high repetition rates.

  15. Fluorescence properties and electron paramagnetic resonance studies of {gamma}-irradiated Sm{sup 3+}-doped oxyfluoroborate glasses

    SciTech Connect

    Babu, B. Hari; Ravi Kanth Kumar, V. V.

    2012-11-01

    The permanent photoinduced valence manipulation of samarium doped oxyfluoroborate glasses as a function of {gamma}-ray irradiation has been investigated using a steady-state fluorescence and electron paramagnetic resonance techniques. An increase in SrF{sub 2} content in the glass led to the red shift of the peaks in as prepared glass, while in irradiated glasses this led to the decrease in defect formation as well as increase in photoreduction of Sm{sup 3+} to Sm{sup 2+} ion. The energy transfer mechanism of induced permanent photoreduction of Sm{sup 3+} to Sm{sup 2+} ions in oxyfluoroborate glasses has been discussed. The decay analysis shows exponential behavior before irradiation and non-exponential behavior after irradiation. The energy transfer in irradiated glasses increases with the increase in SrF{sub 2} content in the glass and also with the irradiation dose.

  16. Luminescence properties of Sm(3+)-doped P(2)O(5)-PbO-Nb(2)O(5) glass under high pressure.

    PubMed

    Praveena, R; Venkatramu, V; Babu, P; Jayasankar, C K; Trster, Th; Sievers, W; Wortmann, G

    2009-01-21

    Samarium doped lead phosphate glass modified with niobium having a composition (in mol%) of 55P(2)O(5)+39.5PbO+5Nb(2)O(5)+0.5Sm(2)O(3) has been prepared by the conventional melt quenching technique. The emission spectra and the decay curves for the (4)G(5/2) level of Sm(3+) ions have been measured as a function of pressure up to 23.6GPa at room temperature. A discontinuity in the observed shifts and crystal-field splittings as a function of pressure around 9-10GPa suggests that a phase transition is taking place in the glass matrix. The [Formula: see text], (6)H(7/2) and (6)H(9/2) transitions are shifted towards the lower energy side with magnitudes of -7.1, -7.6 and -5.5cm(-1)GPa(-1) up to 8.9GPa (phase1) and -5.6, -4.9 and -4.4cm(-1)GPa(-1) beyond 10.3GPa (phase2), respectively. A much stronger increase in the splitting of the [Formula: see text] and [Formula: see text] Stark levels with pressure is observed in phase1 than in phase2. The lifetime of the (4)G(5/2) level decreases from 2.29ms (0GPa) to 0.64ms (23.6GPa) with pressure. The decay curves of the (4)G(5/2) level exhibit non-exponential behavior for all the pressures and were fitted by the generalized Yokota-Tanimoto model to probe the nature of the energy transfer process. The best fits with S = 6 indicate that the energy transfer between donor and acceptor is of dipole-dipole type. The crystal-field splitting experienced by the Sm(3+) ions in the title glass are found to be larger than those found in borate, K-Ba-Alphosphate and tellurite glasses. PMID:21817267

  17. The Brillouin gain coefficient of Yb-doped aluminosilicate glass optical fibers

    NASA Astrophysics Data System (ADS)

    Dragic, Peter D.; Ballato, John; Morris, Stephanie; Hawkins, Thomas

    2013-07-01

    Provided herein is a detailed analysis of the Brillouin spectroscopy of the ytterbia (Yb2O3) dopant in aluminosilicate glass optical fibers. Yb-doped fiber lasers have become ubiquitous, and the results presented here may be used to design lasers and amplifiers for narrow linewidth systems and applications. It is found, with a high degree of certainty, that Yb2O3 has an acoustic velocity that is lower than that of silica, a Brillouin spectral width (or material acoustic damping coefficient) that is about 80 times greater than that of silica, and photoelastic constants (Pockels' coefficients) that are negative. It is found that the primary influence of ytterbia in concentrations typical of active fibers is to broaden the Brillouin gain spectrum, thereby reducing the peak Brillouin gain. A set of design curves is provided outlining the Brillouin gain coefficient as a function of alumina concentration for several ytterbia concentrations, which can be utilized to design fiber structures with reduced Brillouin gain. The Yb-doped aluminosilicate fiber system is compared to the Yb-doped phosphosilicate system, and a high degree of similarity is found between them at low Al2O3 or P2O5 doping levels. However, for fiber produced utilizing conventional techniques, the phosphosilicates are found to have the potential for lower Brillouin gain since more P2O5 can be reliably incorporated into the glassy matrix.

  18. Ultra-broadband amplification properties of Ni2+-doped glass-ceramics amplifiers.

    PubMed

    Jiang, Chun

    2009-04-13

    The energy level, transition configuration and mathematical model of Ni(2+)-doped glass-ceramics amplifiers are presented for the first time, to the best of one's knowledge. A quasi-three-level system is employed to model the gain and noise characteristics of the doped system, and the rate and power propagation equations of the mathematical model are solved to analyze the effect of the active ion concentration, fiber length, pump power as well as thermal-quenching on the gain spectra. It is shown that our model is in agreement with experimental result, and when excited at longer wavelength, the center of gain spectra of the amplifier red shifts, the ultra-broad band room-temperature gain spectra can cover 1.25-1.65 microm range for amplification of signal in the low-loss windows of the all-wave fiber without absorption peak caused by OH group. PMID:19365505

  19. Sm3+ effects in the Tm3+ doped tellurite glass for S-band amplification

    NASA Astrophysics Data System (ADS)

    Belanon, Marcos P.; Ferenz, Julio; Chillcce, Enver; Barbosa, Luis Carlos

    2013-02-01

    Thulium doped Samarium codoped tellurite-tungstate glasses were produced. Luminescence properties in the infrared region were investigated looking to observe improved properties for S-band amplification in the co doped samples. Thulium is well-known by the 3H4-3F4 radiative transition emitting around ~1.47?m, which is a self-terminating transition in tellurite hosts due the longer lifetime of the lower level in relation to the upper level of this transition. Analysis of absorption and emission spectra showed that we could quench the 3F4 level significantly, what improved the intensity of the emission at 1.49?m. However, the state 3H4 were also quenched due the cross relaxation process due the absorption bands of Sm3+ around 1.5?m.

  20. Two-coherent-wave coupling in Rhodamine 110-doped boric acid glass solid films

    NASA Astrophysics Data System (ADS)

    Sharma, Ramesh C.; Barman, Anjan; Thakur, Surya N.; Singh, Jagdish P.

    2007-05-01

    We report the energy-transfer efficiency in a saturable absorber nonlinear media by two-coherent-wave coupling using the Doppler shift. Intensity-dependent nondegenerate two-beam coupling has been studied in Rhodamine 110-doped boric acid glass films. Two beams have been described in the limit of a weak probe and a relatively strong pump at the wavelength 488 nm from a continuous-wave Ar+ laser. The results have been interpreted in terms of the four-level description of a saturable absorber. We obtained good agreement between the experimental and the theoretical results. Estimated values of the nonlinear parameters such as the saturation intensity, refractive index, and the response time of the optical nonlinearity have been obtained at different pump beam intensities for the first time, to our knowledge, in the Rhodamine 110-doped film.

  1. Evidence of a cluster glass-like behavior in Fe-doped ZnO nanoparticles

    NASA Astrophysics Data System (ADS)

    Ramos, J. E.; Montero-Muñoz, M.; Coaquira, J. A. H.; Rodríguez-Páez, J. E.

    2014-05-01

    We report on the study of the structural and magnetic properties of crystalline Fe-doped ZnO nanoparticles with Fe content up to 10% synthesized by a co-precipitation method. The Rietveld analysis indicates that the Fe-doped ZnO nanoparticles are formed in a single phase wurtzite structure. DC magnetization (M) vs. applied magnetic field (H) curves obtained at 5 K show the occurrence of a ferromagnetic behavior. The coercive field and saturation magnetization depend on the Fe content. At room temperature, M vs. H curves show features consistent with a superparamagnetic state of nanoscale system. The temperature dependence of the AC and DC magnetic susceptibilities show features related to the thermal relaxation of the nano-sized particles. From the AC data analysis, a magnetic transition from the superparamagnetic to cluster-glass state is determined.

  2. Higher Fe{sup 2+}/total Fe ratio in iron doped phosphate glass melted by microwave heating

    SciTech Connect

    Mandal, Ashis K.; Sinha, Prasanta K.; Das, Dipankar; Guha, Chandan; Sen, Ranjan

    2015-03-15

    Highlights: • Iron doped phosphate glasses prepared using microwave heating and conventional heating under air and reducing atmosphere. • Presence of iron predominantly in the ferrous oxidation state in all the glasses. • Significant concentrations of iron in the ferrous oxidation state on both octahedral and tetrahedral sites in all the glasses. • Ratio of Fe{sup 2+} with total iron is found higher in microwave prepared glasses in comparison to conventional prepared glasses. - Abstract: Iron doped phosphate glasses containing P{sub 2}O{sub 5}–MgO–ZnO–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3} were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV–Vis–NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed presence of iron predominantly in the ferrous oxidation state on two different sites in all the glasses. The intensity of the ferrous absorption peaks in UV–Vis–NIR spectrum was found to be more in glasses prepared using microwave radiation compared to the glasses prepared in a resistance heating furnace. Thermogravimetric analysis showed increasing weight gain on heating under oxygen atmosphere for glass corroborating higher ratio of FeO/(FeO + Fe{sub 2}O{sub 3}) in glass melted by direct microwave heating. Wet chemical analysis also substantiated the finding of higher ratio Fe{sup +2}/ΣFe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

  3. The relationship between magnetism and magneto-optical effects in rare earth doped aluminophosphate glasses

    NASA Astrophysics Data System (ADS)

    Valeanu, M.; Sofronie, M.; Galca, A. C.; Tolea, F.; Elisa, M.; Sava, B.; Boroica, L.; Kuncser, V.

    2016-02-01

    Aluminophosphate glasses from the Li2O-BaO-Al2O3-P2O5 system with the addition of nonmagnetic and paramagnetic rare earth ions, were prepared using a wet nonconventional method to process the raw materials, followed by a meltingquenching procedure. The glasses obtained were characterized with respect to their magnetic and magneto-optical properties using superconducting quantum interference device magnetometry and spectroscopic ellipsometry. The assumption of a linear dependence of the Verdet constant on the magnetic susceptibility, with a proportionality constant dependent on the type of vitreous matrix and doping ion, is critically discussed. The diamagnetic and paramagnetic contributions to the Faraday rotation were separately analyzed and specific designs for optimal active and passive elements are proposed.

  4. Luminescent Properties of Eu3+-Doped Yttrium Oxide Chloride Embedded in Nanoporous Glass

    NASA Astrophysics Data System (ADS)

    Zeng, Xiao-Qing; Lin, Feng-Ying; Gan, Fu-Xi; Yuan, Sui-Hua

    2002-11-01

    The photoluminescence of Eu3+-doped yttrium oxide chloride embedded in nanoporous glass has been observed. In comparison with those in the powder phosphor, the emission lines of Eu3+ ions become much broader and blueshift was observed in the lines due to 5D0?7F2 transitions and the Eu-O charge transfer excitation band. The ratio intensities of the 5D0?7F1 transitions to the 5D0?7F2 transitions of Eu3+ ion become higher and change at different excitation wavelengths, such as 393 nm and 254 nm. The two excitation wavelengths belong to the 4f?4f transition of the Eu3+ ion and the Eu-O charge transfer, respectively. This material may be developed into a new luminescent glass.

  5. Spectroscopic properties of magnesium aluminosilicate glass-ceramics doped with divalent cobalt ions

    NASA Astrophysics Data System (ADS)

    Malyarevich, A. M.; Denisov, I. A.; Yumashev, K. V.; Dymshits, O. S.; Zhilin, A. A.; Shashkin, A. V.

    2002-10-01

    Electronic absorption and luminescence spectra and nonlinear optical properties of magnesium aluminosilicate glass-ceramics doped with divalent cobalt ions are studied in relation to their synthesis conditions. The lifetimes of the 4 T 1(4 P) and 4 T 1(4 F) excited levels of tetracoordinate Co2+ ions in these glass-ceramics are found to depend on the cobalt concentration and lie within the ranges from 25 to 40 and from 120 to 450 ns, respectively. Using the absorption saturation curves, the ground state absorption cross section for the wave-length of 1.54 μm is estimated to be σGSA=3.3×10-19cm2. The induced emission of the tetrahedrally coordinated Co2+ ion, which dominates over the absorption from the excited state in the spectral range from 640 to 690 nm (4 T 1(4 P)→4 A 2 transition), is found.

  6. Near infrared luminescence in Yb3+/Ho3+: co-doped germanate glass

    NASA Astrophysics Data System (ADS)

    Kochanowicz, Marcin; ?mojda, Jacek; Miluski, Piotr; Ragin, Tomasz; Jele?, Piotr; Sitarz, Maciej; Dorosz, Dominik

    2015-12-01

    The near-infrared emission of low phonon (805 cm-1) germanate glasses from GeO2-Ga2O3-BaO system co-doped with 0.7Yb2O3/(0.07-0.7)Ho2O3 ions has been investigated. Luminescence at 2.1 ?m corresponding to 5I7 ? 5I8 transition in holmium was obtained by energy transfer between Yb3+ and Ho3+ ions. The optimization of the activator content and the concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer and as a consequence luminescence intensity at 2mm. The highest value of the luminescence intensity was obtained in glass codoped with 0.7Yb2O3/0.15 Ho2O3.

  7. Mid-infrared emission and Raman spectra analysis of Er(3+)-doped oxyfluorotellurite glasses.

    PubMed

    Chen, Fangze; Xu, Shaoqiong; Wei, Tao; Wang, Fengchao; Cai, Muzhi; Tian, Ying; Xu, Shiqing

    2015-04-10

    This paper reports on the spectroscopic and structural properties in Er(3+)-doped oxyfluorotellurite glasses. The compositional variation accounts for the evolutions of Raman spectra, Judd-Ofelt parameters, radiative properties, and fluorescent emission. It is found that, when maximum phonon energy changes slightly, phonon density plays a crucial role in quenching the 2.7 ?m emission generated by the Er(3+):(4)I11/2?(4)I13/2 transition. The comparative low phonon density contributes strong 2.7 ?m emission intensity. The high branching ratio (18.63%) and large emission cross section (0.9510(-20)??cm(2)) demonstrate that oxyfluorotellurite glass contained with 50 mol.% TeO2 has potential application in the mid-infrared region laser. PMID:25967322

  8. Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

    PubMed

    Xu, Tie-Feng; Li, Guang-Po; Nie, Qiu-Hua; Shen, Xiang

    2006-06-01

    Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed. PMID:16458052

  9. Blue cooperative luminescence in Yb3+-doped barium gallogermanate glass excited at 976 nm.

    PubMed

    Xiao, Kai; Yang, Zhongmin

    2006-11-01

    The Yb3+-doped barium gallogermanate glass has been prepared via the conventional melt method. The absorption spectra, the near infrared emission spectra, the upconversion emission spectra and the differential scanning calorimetry have been measured. Bright blue upconversion emission centered at 476 nm has been observed under the 976 nm laser diode excitation at room temperature. The blue upconversion emission mechanism has been discussed on the blue emission intensity and the measured lifetime. The slope of the log-log plot of the blue emission intensity versus the pump power is equal to 1.98, and the blue luminescence decay time is half of the near infrared fluorescence decay time, confirming that the blue emission comes from Yb3+-Yb3+ pairs cooperative upconversion mechanism. The result of differential scanning calorimetry suggests that this type of glass is suitable as a potential candidate for fiber drawing. PMID:17061162

  10. Spectroscopic Studies on Eu{sup 3+} Doped Boro-Tellurite Glasses

    SciTech Connect

    Selvaraju, K.; Marimuthu, K.

    2011-07-15

    Eu{sup 3+} doped boro-tellurite glasses have been synthesized and its optical behavior have been studied and reported. The presence of varying tellurium dioxide content results changes in spectroscopic behavoir were explored through UV-VIS, and Luminescence spectra. The bonding parameters have been calculated based on the observed band positions of the absorption spectra. The Judd-Ofelt intensity parameters {Omega}{sub {lambda}} ({lambda} = 2, 4 and 6) have been determined through the luminescence spectra without applying any constraints and the results are presented. The Judd-Ofelt parameters have been used to determine various optical properties corresponding to {sup 5}D{sub 0}{yields}{sup 7}F{sub J}(J = 1,2,3 and 4) transitions of Eu{sup 3+} ions. The varying optical properties of the prepared glasses with the change in tellurium dioxide have been studied and compared with similar studies.

  11. Spatially resolved measurement of high doses in microbeam radiation therapy using samarium doped fluorophosphate glasses

    SciTech Connect

    Okada, Go; Morrell, Brian; Koughia, Cyril; Kasap, Safa; Edgar, Andy; Varoy, Chris; Belev, George; Wysokinski, Tomasz; Chapman, Dean

    2011-09-19

    The measurement of spatially resolved high doses in microbeam radiation therapy has always been a challenging task, where a combination of high dose response and high spatial resolution (microns) is required for synchrotron radiation peaked around 50 keV. The x-ray induced Sm{sup 3+}{yields} Sm{sup 2+} valence conversion in Sm{sup 3+} doped fluorophosphates glasses has been tested for use in x-ray dosimetry for microbeam radiation therapy. The conversion efficiency depends almost linearly on the dose of irradiation up to {approx}5 Gy and saturates at doses exceeding {approx}80 Gy. The conversion shows strong correlation with x-ray induced absorbance of the glass which is related to the formation of phosphorus-oxygen hole centers. When irradiated through a microslit collimator, a good spatial resolution and high ''peak-to-valley'' contrast have been observed by means of confocal photoluminescence microscopy.

  12. CsH5(PO4)2 doped glass membranes for intermediate temperature fuel cells

    NASA Astrophysics Data System (ADS)

    Qing, Geletu; Kikuchi, Ryuji; Takagaki, Atsushi; Sugawara, Takashi; Oyama, Shigeo Ted

    2014-12-01

    This study reports the preparation of glass membranes doped with CsH5(PO4)2 by an optimized sol-gel method using phosphoric acid as a catalyst for tetraethylorthosilicate (TEOS) hydrolysis and the application of these membranes in intermediate temperature fuel cells (ITFCs). Infrared spectroscopy shows the formation of Si-O-P bonds and scanning electron microscopy shows that the glass membranes have smooth cross-sectional structures. Domains of CsH5(PO4)2 with sizes of 5-12 nm are uniformly distributed over the membrane cross section. The melting point of CsH5(PO4)2 in the glass membrane is lower by 20-40 C than that for pure CsH5(PO4)2. For a glass membrane with a molar ratio of SiO2:CsH5(PO4)2:H3PO4 = 4:1:0.36, 62% of the pore volume is filled with CsH5(PO4)2 and shows the best electrochemical performance. The glass membrane shows high conductivity of 22 mS cm-1 at 219 C. The membrane is novel because the silica support forms an interconnected matrix that provides stability, as shown by continuous operation at 210 C for at least 50 h. A fuel cell assembled with the glass membrane exhibits an open circuit voltage of 0.94 V and a peak power density of 85 mW cm-2. The fuel cell produces a stable output voltage of 0.53 V for at least 50 h under a current density of 100 mA cm-2.

  13. Structural and luminescence studies of Ho3+-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

    NASA Astrophysics Data System (ADS)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y. C.

    2015-06-01

    Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (AR), branching ratios (?R), radiative lifetimes (?R) were calculated and discussed. From the emission spectra emission peak positions (?P), effective bandwidths (??eff) and stimulated emission cross-sections (?P) were calculated for the observed emission transitions,5S2 (5F4?5I8) and 5F5?5I8 in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation.

  14. Broad-Spectrum Bactericidal Activity of Ag2O-Doped Bioactive Glass

    PubMed Central

    Bellantone, Maria; Williams, Huw D.; Hench, Larry L.

    2002-01-01

    Bioactive glass has found extensive application as an orthopedic and dental graft material and most recently also as a tissue engineering scaffold. Here we report an initial investigation of the in vitro antibacterial properties of AgBG, a novel bioactive glass composition doped with Ag2O. The bacteriostatic and bactericidal properties of this new material and of two other bioactive glass compositions, 45S5 Bioglass and BG, have been studied by using Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus as test microorganisms. Concentrations of AgBG in the range of 0.05 to 0.20 mg of AgBG per ml of culture medium were found to inhibit the growth of these bacteria. Not only was AgBG bacteriostatic, but it also elicited a rapid bactericidal action. A complete bactericidal effect was elicited within the first hours of incubation at AgBG concentrations of 10 mg ml−1. 45S5 Bioglass and BG had no effect on bacterial growth or viability. The antibacterial action of AgBG is attributed exclusively to the leaching of Ag+ ions from the glass matrix. Analytical measurements rule out any contribution to AgBG-mediated bacterial killing by changes in pH or ionic strength or the dissolution of other ionic species from the biomaterials. Our observations of the dissolution profiles of Ag+ from AgBG in the presence and absence of bacteria are consistent with silver accumulation by the bacteria. PMID:12019112

  15. Nano-silver enhanced luminescence of Eu3+-doped lead tellurite glass

    NASA Astrophysics Data System (ADS)

    Reza Dousti, M.; Sahar, M. R.; Rohani, M. S.; Samavati, Alireza; Mahraz, Zahra Ashur; Amjad, Raja J.; Awang, Asmahani; Arifin, R.

    2014-05-01

    Eu3+-doped lead sodium tellurite glasses containing silver nanoparticles (NPs) were synthesized by melt-quenching technique and annealed for different time intervals at above the glass transition temperature. The glasses were characterized by UV-Vis-IR absorption, photoluminescence spectroscopy and transmission electron microscope imaging. Four absorption peaks of Eu3+ ion were observed due to transitions from ground state to different excited states in 400-600 nm region. The surface plasmon resonance (SPR) peak of silver NPs was probed at 632 nm. Five emission lines were recorded at 568, 587, 614, 650 and 704 nm which were intensified in the order of 1.9 times for heat-treated samples containing silver NPs. The average size of NPs was estimated to be 10 nm. Different mechanisms for interaction of light with metal and luminescent ions are discussed. Such enhancements are attributed to the strong local electric field induced by SPR of silver NPs as the major factor, and energy transfer from surface of silver NP to Eu3+ ion. The glasses show promising properties for optical applications.

  16. Antibacterial and bioactive composite bone cements containing surface silver-doped glass particles.

    PubMed

    Miola, Marta; Fucale, Giacomo; Maina, Giovanni; Vern, Enrica

    2015-09-01

    A bioactive silica-based glass powder (SBA2) was doped with silver (Ag(+)) ions by means of an ion-exchange process. Scanning electron microscopy (SEM), energy dispersion spectrometry (EDS) and x-ray diffraction (XRD) evidenced that the glass powder was enriched with Ag(+) ions. However, a small amount of Ag2CO3 precipitated with increased Ag concentrations in the exchange solution. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of Ag-SBA2 towards Staphylococcus aureus were also evaluated and were respectively 0.05?mg ml(-1) and 0.2?mg ml(-1). Subsequently, Ag-SBA2 glass was used as filler (30%wt) in a commercial formulation of bone cement (Simplex() P) in order to impart both antibacterial and bioactive properties. The composite bone cement was investigated in terms of morphology (using SEM) and composition (using EDS); the glass powder was well dispersed and exposed on the cement surface. Bioactivity tests in simulated body fluid (SBF) evidenced the precipitation of hydroxyapatite on sample surfaces. Composite cement demonstrated antibacterial properties and a compressive strength comparable to the commercial formulation. PMID:26481324

  17. Analysis of thermal and structural properties of germanate glasses co-doped with Yb3+/Tb3+ ions

    NASA Astrophysics Data System (ADS)

    Zmojda, J.; Kochanowicz, M.; Miluski, P.; Dorosz, D.; Jelen, P.; Sitarz, M.

    2014-10-01

    In the work the new glass compositions in the GeO2-GaO-BaO system have been prepared and thermal, structural properties of in germanate glasses co-doped with Yb3+/Tb3+ions were studied. Glasses were obtained by conventional high-temperature melt-quenching technique. The study of the crystallization kinetics processes of glasses co-doped with 0.7Yb2O3:0.7Tb2O3 was performed with DSC measurements. The activation energies have been calculated using Freedman analysis and verified with the Flynn-Wall-Ozawa method. In this order, the DSC curves have been registered with different heating rates, between 5 and 15 degrees/min. The structure of fabricated glasses has been studied by infrared and Raman spectroscopes. The effect of heat treatment on the structural properties was determined. In all glass samples the dominated infrared absorbance band at 800 cm-1 corresponds to asymmetric stretching motions of GeO4 tetrahedra containing bridging (Ge-O(Ge)) and non-bridging (Ge-O-) oxygens. Additionally, the influence of heat treatment on the luminescent properties was evaluated. Strong luminescence at 489, 543, 586 and 621 nm corresponding to 5D4 ? 7FJ (J = 6, 5, 4, 3) transitions was measured. The highest upconversion emission intensity was obtained in the germanate glass co-doped with 0.7Yb2O3/0.7Tb2O3.

  18. Structural, thermal and optical investigations of Dy3+ ions doped lead containing lithium fluoroborate glasses for simulation of white light

    NASA Astrophysics Data System (ADS)

    Zulfiqar Ali Ahamed, Sd.; Madhukar Reddy, C.; Deva Prasad Raju, B.

    2013-05-01

    Lead containing barium zinc lithium fluoroborate (LBZLFB) glasses doped with different concentrations of trivalent dysprosium ions were synthesized by conventional melt quenching method and characterized through the XRD, DSC, FTIR, FT-Raman, optical absorption, photoluminescence and decay curve analysis. X-ray diffraction studies revealed amorphous nature of the studied glass matrices. The thermal behavior has been reported by recording DSC thermograms. Coexistence of trigonal BO3 and tetrahedral BO4 units was evidenced by IR and Raman spectroscopy. Judd-Ofelt intensity parameters have been evaluated for 1.0 mol% Dy3+ ions doped LBZLFB glass. The measuring branching ratios are reasonably high for transitions 4F9/2 ? 6H15/2 and 6H13/2 suggesting that the emission at 486 and 577 nm, respectively can give rise to lasing action in the visible region. From the visible emission spectra, the yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were estimated. A combination of blue and yellow emissions has emerged in the glasses, which allows the observation of white light when the glasses are excited by the ultraviolet/blue light. These Dy3+ doped glasses are studied for their utility for white light generation under 454 nm excitation and the present LBZLFB glass is more suitable for generation of white light for blue LED chips.

  19. Spectroscopic properties of Er3+ and Yb3+ co-doped glass ceramics containing SrF2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Qiao, Xvsheng; Fan, Xianping; Wang, Minquan; Zhang, Xianghua

    2009-03-01

    The spectroscopic properties of Er3+/Yb3+ co-doped 50SiO2-10Al2O3-20ZnF2-20SrF2 glass and glass ceramic containing SrF2 nanocrystals were investigated. The formation of SrF2 nanocrystals in the glass ceramic was confirmed by XRD. The oscillator strengths for several transitions of the Er3+ ions in the glass ceramic have been obtained and the Judd-Ofelt parameters were then determined. The XRD result and Judd-Ofelt parameters suggested that Er3+ and Yb3+ ions had efficiently enriched in the SrF2 nanocrystals in the glass ceramic. The lifetime of excited states has been used to reveal the surroundings of luminescent Er3+ and Yb3+ and energy transfer (ET) mechanism between Er3+ and Yb3+. Much stronger upconversion luminescence and longer lifetime of the Er3+/Yb3+ co-doped glass ceramic were observed in comparison with the Er3+/Yb3+ co-doped glass, which could be ascribed to more efficient ET from Yb3+ to Er3+ due to the enrichment of Yb3+ and Er3+ and the shortening of the distance between lanthanide ions in the precipitated SrF2 nanocrystals.

  20. Formation of Al-doped ZnO thin films on glass by sol-gel process and characterization

    NASA Astrophysics Data System (ADS)

    Shahid, M. U.; Deen, K. M.; Ahmad, A.; Akram, M. A.; Aslam, M.; Akhtar, W.

    2016-02-01

    In this study, pure ZnO and Al-doped ZnO thin films were developed on glass by sol-gel process followed by drying and annealing in air at 170 and 400 °C, respectively. The surface morphology and structural characteristics were determined through scanning electron microscopy, atomic force microscopy and X-ray diffraction. The Fourier transform infrared spectroscopy validated the formation of Al-doped ZnO film on glass substrate. It was evaluated that 1 at% aluminum (Al) doping in ZnO film showed low electrical resistivity and higher charge carrier concentration due to uniformly dispersed regular shape crystallites as compared to pure ZnO and 2 at% `Al'-doped thin films.

  1. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

  2. Mid-infrared fiber laser application: Er 3+-doped chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Moizan, Virginie; Nazabal, Virginie; Troles, Johann; Houizot, Patrick; Adam, Jean-Luc; Smektala, Frdric; Doualan, Jean-Louis; Moncorg, Richard; Canat, Guillaume; Cariou, Jean-Pierre

    2007-02-01

    Mid-infrared (IR) lasers are of interest for a variety of applications including environmental sensing, LIDAR and military counter measures. However, this wavelength range lacks powerful, coherent, robust and compact sources. A solution can lie in chalcogenide glasses as host materials for rare earth ions. With an extended infrared transparency, low phonon energy limiting the non radiative multiphonon relaxation rates and suitable rare earth solubility, sulfide glasses based on Ge-Ga-Sb-S system make available radiative transitions in the mid-IR range. The glasses with nominal composition of Ge 20Ga 5Sb 10S 65 doped with Er 3+ (500 to 10000 ppm) were prepared by means of conventional melting and quenching method. The Er 3+, widely studied in glass fibers for near-IR amplification, was initially selected for the transition 4I 9/2 to 4I 11/2 emitting at around 4.5 ?m in order to demonstrate the ability of this sulfide composition for midinfrared fiber lasers application. In these objectives, absorption and emission spectra have been recorded and the radiative decay lifetime of excited levels ( 4I 9/2, 4I 11/2 and 4I 13/2) has been determined. These last experimental results were compared with those obtained by Judd-Ofelt model from absorption cross-sections of all observable transitions. Therefore, the 4I 9/2 radiative quantum efficiency was estimated at 67 %. The emission cross-section was 2.6x10 -21 cm2 at 4.6 ?m obtained by Ftchbauer-Ladenburg theory. The product of measured lifetime and emission cross-section for 4I 9/2 -> 4I 11/2 transition is about 1.87x10 -24 cm2.s is comparable with that for GaLaS glasses. The fiber drawing of the Er 3+ doped Ge 20Ga 5Sb 10S 65 glasses and measurements of optical losses in mid-IR are currently in progress and first results were presented.

  3. Luminescence and spectroscopic properties of ZnF2-MO-TeO2 glasses doped with Ho3+ ions

    NASA Astrophysics Data System (ADS)

    Laxmikanth, C.; Anjaiah, J.; Venkateswara Rao, P.; Appa Rao, B.; Veeraiah, N.

    2015-08-01

    ZnF2-TeO2 glasses mixed with the three different modifier oxides (MO) viz., ZnO, CdO and PbO doped with Ho2O3 were prepared. These glasses were characterized by X-ray diffraction, and IR spectra. Optical absorption and fluorescence spectra of these glasses have been studied. From the measured intensities of various absorption bands of these glasses the Judd-Ofelt parameters ?? (? = 2, 4, 6) have been evaluated and compared with those of other reported glass systems. From the Judd-Ofelt theory various radiative properties like transition probability A, branching ratio ?R, the radiative life time ?R, and the emission cross-section ?P for various emission levels of these glasses have been determined and reported.

  4. Luminescence properties of Eu3+-doped SiO2-LiYF4 glass-ceramic microrods

    NASA Astrophysics Data System (ADS)

    Secu, C. E.; Secu, M.

    2015-09-01

    Photoluminescence properties of the glass-ceramics microrods containing Eu3+-doped LiYF4 nanocrystals have been studied and characterized. Judd-Ofelt parameters and quantum efficiency has been computed from luminescence spectra and discussed by comparison to the glass ceramic bulk and pellet. The radiative decay rate Arad is higher in the glass ceramic rods (221 s-1) than in the glass ceramic bulk (130 s-1) but the quantum efficiency computed is very low (21%) compared to the glass-ceramic bulk (97%). There are effective non-radiative decay channels that might be related to an influence of the dimensional constraints imposed by the membrane pores during xerogel formation and subsequent glass ceramization.

  5. Concentration and temperature effects on the spectroscopic properties of Tb3+ doped borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Yamashita, Tatsuya; Ohishi, Yasutake

    2007-12-01

    The spectroscopic properties of Tb3+ doped borosilicate glasses were investigated to assess their potential as gain media in the 0.54?m band. Analysis of the concentration and temperature dependences of the optical transitions from the D45 level of Tb3+ was carried out. The emission lifetime of the D45 level at 300K was found to be 2.610.03ms and almost invariant for Tb3+ concentrations less than 15wt% (1.681021ions/cm3). Judd-Ofelt analysis was used to calculate the emission transition probabilities from the D45 level, and the emission cross section at 300K for the D45?F57 transition was 8.110-22cm2 at 541nm. Temperature dependent nonradiative relaxation of the D45 level was observed in samples with 5 and 20wt% Tb3+. The quenching process of the D45 level in the temperature range of 50-373K might have been caused by a two-photon one-site resonant process, whereas it was dominated by a two-site nonresonant process at temperatures below 40K. The results obtained indicate that Tb3+ doped borosilicate glass is a promising candidate for optical gain media in the green (0.54?m) band.

  6. Influence of Er{sup 3+} doping on microstructure of oxyfluoride glass-ceramics

    SciTech Connect

    Bao Feng; Wang Yuansheng . E-mail: yswang@fjirsm.ac.cn; Hu Zhongjian

    2005-10-06

    Oxyfluoride glasses with composition of 45SiO{sub 2}.20Al{sub 2}O{sub 3}.30PbF{sub 2}.5ZnF{sub 2} by molar ratio with a high stability against crystallization have been obtained by melt quenching. After doping with x (x = 1, 2, 4) mol% of Er{sup 3+} transparent or translucent glass-ceramics could be formed. The structural transformations of these materials were investigated by thermal analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Spherical polycrystalline aggregates comprised of many nanosized and randomly oriented {beta}-PbF{sub 2} grains were embedded separately among glassy matrix. On heating these nanosized grains merge with their neighbors to form bigger single crystals in a way like Ostwald ripening. The size modification of polycrystalline aggregates in the samples was found to be dependent on Er{sup 3+} doping.

  7. Optical and spectroscopic characterization of Er3+-Yb3+co-doped tellurite glasses and fibers

    NASA Astrophysics Data System (ADS)

    Narro-Garca, R.; Desirena, H.; Chillcce, E. F.; Barbosa, L. C.; Rodriguez, E.; De la Rosa, E.

    2014-04-01

    Optical and spectroscopic properties of Er3+-Yb3+ co-doped TeO2-WO3-Nb2O5-Na2O-Al2O3 glasses and fibers were investigated. Emission spectra and fluorescence lifetimes of 4I13/2 level of Er3+ion as a function of rare earth concentration and fiber length were measured in glasses. Results show that the self-absorption effect broadens the spectral bandwidth of 4I13/2?4I15/2 transition and lengthens the lifetime significantly from 3.5 to 4.6 ms. Fibers were fabricated by the rod-in-tube technique using a Heathway drawing tower. The emission power of these Er3+-Yb3+ co-doped Step Index Tellurite Fibers (SITFs; lengths varying from 2 to 60 cm) were generated by a 980 nm diode laser pump and then the emission power spectra were acquired with an OSA. The maximum emission power spectra, within the 1530-1560 nm region, were observed for fiber lengths ranging from 3 to 6 cm. The highest bandwidth obtained was 108 nm for 8 cm fiber length around 1.53 m.

  8. Broadband near-infrared emission from Tm3+/Er3+ co-doped nanostructured glass ceramics

    NASA Astrophysics Data System (ADS)

    Chen, Daqin; Wang, Yuansheng; Bao, Feng; Yu, Yunlong

    2007-06-01

    Transparent SiO2-Al2O3-NaF-YF3 glass ceramics co-doped with Er3+ and Tm3+ were prepared by melt quenching and subsequent heating. X-ray diffraction and transmission electron microscopy experiments revealed that β-YF3 nanocrystals incorporated with Er3+ and Tm3+ were precipitated homogeneously among the oxide glass matrix. An integrated broad near-infrared emission band in the wavelength region of 1300-1700 nm, consisting of Tm3+ emissions around 1472 nm (H34→F34) and 1626 nm (F34→H36), and Er3+ emission around 1543 nm (I413/2→I415/2), was obtained under 792 nm laser excitation. The full width at half maximum of this integrated band increased with the increasing of [Tm]/[Er] ratio, and it reached as large as 175 nm for the 0.1 mol% Er3+ and 0.8 mol% Tm3+ co-doped sample. The energy transfers between Er3+ and Tm3+ were proposed to play an important role in tailoring the emission bandwidth of the sample.

  9. Local-field approximation of homonuclear dipolar interactions in ⁷Li-NMR: density-matrix calculations and random-walk simulations tested by echo experiments on borate glasses.

    PubMed

    Storek, Michael; Jeffrey, Kenneth R; Böhmer, Roland

    2014-01-01

    NMR echo techniques have proven to be important to study dynamics in ion conductors and other solid materials. Using the spin-3/2 nucleus (7)Li as a probe, both the quadrupolar and the often neglected homonuclear dipolar interactions modulate the NMR frequency as the ion performs jump processes. Retaining only the local-field term of the many-body Hamiltonian, the impact of the dipolar interaction on various echo experiments was studied using spin dynamics calculations yielding products of dipolar and quadrupolar correlation functions. Using a simple stochastic model these functions were simulated with particular emphasis on the impact of ionic motions and on the conditions under which the dipolar and quadrupolar contributions factorize. The results of the computations and of the random-walk simulations are compared with experimental data obtained for various lithium borate and lithium borophosphate glasses. It is concluded that the local-field approximation is a useful means of treating the Li-Li dipole interactions and that the simple model that we introduce is capable of describing many experimentally observed features. Furthermore, because the dipolar and quadrupolar contributions essentially factorize, a selective determination of the corresponding correlation functions becomes possible. PMID:24593983

  10. Structural and luminescence studies on Dy3+ doped lead boro-telluro-phosphate glasses

    NASA Astrophysics Data System (ADS)

    Selvi, S.; Venkataiah, G.; Arunkumar, S.; Muralidharan, G.; Marimuthu, K.

    2014-12-01

    This paper reports results obtained on the structural and luminescence properties of Dy3+doped lead boro-telluro-phosphate glasses prepared following the melt quenching technique. FTIR spectra exhibit the presence of B-O vibrations, P-O-P symmetric vibrations and Te-O stretching modes of TeO3 and TeO6 units. The metal-ligand bond was identified through UV-vis-NIR absorption spectra and to determine the band tailing parameter, direct and indirect band gap energy of the prepared glasses. The Judd-Ofelt (JO) intensity parameters (?2, ?4 and ?6), experimental and theoretical oscillator strengths were also determined and reported. Luminescence measurements were made to determine the transition probability (A), stimulated emission cross-section (?PE) and branching ratio (?R) for the transitions that include 4F9/2?6H11/2, 6H13/2 and 6H15/2 bands. The effect of Dy3+ ion concentration on the intensity ratio of yellow to blue emission bands has also been studied and reported. The lifetime corresponding to the 4F9/2 level of the title glasses has been found to decrease with the increase in Dy3+ ion concentration. The chromaticity coordinates (x,y) have been estimated from the luminescence spectra and the suitability of title glasses for white light applications has been analyzed using CIE chromaticity diagram. The variation of optical properties with the concentration of dysprosium oxide content in the glasses have been studied and reported.

  11. Towards mid-infrared fiber-lasers: rare earth ion doped, indium-containing, selenide bulk glasses and fiber

    NASA Astrophysics Data System (ADS)

    Sakr, H.; Tang, Z.; Furniss, D.; Sojka, L.; Moneim, N. A.; Barney, E.; Sujecki, S.; Benson, T. M.; Seddon, A. B.

    2014-02-01

    Chalcogenide glasses are promising materials for mid-infrared (IR) fiber lasers (i.e. 3 - 25 μm wavelength range). These glasses exhibit low phonon energies, together with large refractive indices, rare earth (RE-) ion solubility and sufficient mechanical and chemical robustness. Optical quality of the fiber is key. Gallium is known to promote RE-ion solubility in chalcogenide glasses, probably forming a [Pr(III)] - Se - [Ga(III)] associated type complex. Here, indium is investigated as an alternative additive to gallium in Pr3+-doped Ge-As-Se chalcogenide glasses. Indium has the same outer electronic structure as gallium. Moreover, indium has the advantage of being heavier than gallium, potentially promoting a lower phonon-energy, local environment of the RE-dopant. Zero to ~2000 ppmw (nominal parts per million by weight) Pr3+- doped Ge-As-In-Se bulk glasses are prepared using the melt-quench method. ~500 ppmw Pr3+- doped Ge-As-In-Se, optically-clad fiber is realized via fiber-drawing of extruded fiberoptic preforms. Fiber absorption and emission spectra are collected and compared with those of the bulk glasses.

  12. Effect of Ga2O3 on the spectroscopic properties of erbium-doped boro-bismuth glasses.

    PubMed

    Ling, Zhou; Ya-Xun, Zhou; Shi-Xun, Dai; Tie-Feng, Xu; Qiu-Hua, Nie; Xiang, Shen

    2007-11-01

    The spectroscopic properties and thermal stability of Er3+-doped Bi2O3-B2O3-Ga2O3 glasses are investigated experimentally. The effect of Ga2O3 content on absorption spectra, the Judd-Ofelt parameters Omega t (t=2, 4, 6), fluorescence spectra and the lifetimes of Er3+:4I 13/2 level are also investigated, and the stimulated emission cross-section is calculated from McCumber theory. With the increasing of Ga2O3 content in the glass composition, the Omega t (t=2, 4, 6) parameters, fluorescence full width at half maximum (FWHM) and the 4I 13/2 lifetimes of Er3+ first increase, reach its maximum at Ga2O3=8 mol.%, and then decrease. The results show that Er3+-doped 50Bi2O3-42B2O3-8Ga2O3 glass has the broadest FWHM (81nm) and large stimulated emission cross-section (1.03 x1 0(-20)cm2) in these glass samples. Compared with other glass hosts, the gain bandwidth properties of Er+3-doped Bi2O3-B2O3-Ga2O3 glass is better than tellurite, silicate, phosphate and germante glasses. In addition, the lifetime of 4I 13/2 level of Er(3+) in bismuth-based glass, compared with those in other glasses, is relative low due to the high-phonon energy of the B-O bond, the large refractive index of the host and the existence of OH* in the glass. At the same time, the glass thermal stability is improved in which the substitution of Ga2O3 for B2O3 strengthens the network structure. The suitability of bismuth-based glass as a host for a Er3+-doped broadband amplifier and its advantages over other glass hosts are also discussed. PMID:17350330

  13. Engineering of the extraordinary optical transmission of metallic gratings via Er3+-doped tellurite glass

    NASA Astrophysics Data System (ADS)

    Silva, O. B.; Rivera, Victor A. G.; Marega, E.

    2015-03-01

    Although the properties of extraordinary optical transmission (EOT) due surface plasmon polariton (SPP), which are coupled in metallic slits have been widely studied in the last two decades, their influence on the absorption and transmission spectra from their dielectric substrates has not been deserved the same attention. The choice of a good substrate for implementation not just for gratings, but also for other devices, it is extremely important in order to achieve great applications of the EOT. Good candidates to replace the conventional semiconductor based substrates are the rare earth ions (REI) doped glasses. The specific case of Erbium ions and its implementation into glasses for the fabrication of fiber optics, as Erbium doped fiber amplifiers (EDFA). The transmission observed through the plasmonic nanostructures is elucidated considering the following effects: (i) white light absorption by the Er3+ ions, (ii) coupling between the light and the nanostructure via the creation of surface plasmon polariton where the wavelengths with minimums transmission corresponds to the 4I15/2 ? [2H9/2, 4F3/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2] absorption levels the Er3+, which propagates through the slits, and, finally, (iii) the Er3+ transmission intensity and the spectral shape -symmetry depend on the nature of metallic film and the number of slits constituting the arrays, for which the resonant properties are strongly affected. Furthermore, in order to compare the influence of substrate in the transmission properties, we also performed the same measurements on slit arrays fabricated on the BK 7 glass.

  14. Highly Tm(3+) doped germanate glass and its single mode fiber for 2.0??m laser.

    PubMed

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-01-01

    Highly Tm(3+) doped optical fibers are urgently desirable for 2.0??m compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm(3+) doped barium gallo-germanate (BGG) glasses. Highly Tm(3+) doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm(3+) doping concentration reaches 7.6??10(20) ions/cm(3), being the reported highest level in Tm(3+) doped BGG SM fibers. Using ultra short (1.6?cm) as-drawn highly Tm(3+) doped BGG SM fiber, a single-frequency fiber laser at 1.95??m has been demonstrated with a maximum output power of 35?mW when in-band pumped by a home-made 1568?nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95??m has also been achieved in a 10?cm long as-drawn active fiber, yielding a maximum laser output power of 165?mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm(3+) doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber. PMID:26828920

  15. Highly Tm3+ doped germanate glass and its single mode fiber for 2.0 μm laser

    PubMed Central

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-01-01

    Highly Tm3+ doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm3+ doped barium gallo-germanate (BGG) glasses. Highly Tm3+ doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm3+ doping concentration reaches 7.6 × 1020 ions/cm3, being the reported highest level in Tm3+ doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm3+ doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm3+ doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber. PMID:26828920

  16. Highly Tm3+ doped germanate glass and its single mode fiber for 2.0 μm laser

    NASA Astrophysics Data System (ADS)

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-02-01

    Highly Tm3+ doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm3+ doped barium gallo-germanate (BGG) glasses. Highly Tm3+ doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm3+ doping concentration reaches 7.6 × 1020 ions/cm3, being the reported highest level in Tm3+ doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm3+ doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm3+ doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber.

  17. Production and characterization of H3BO3-Li2CO3-K2CO3-MgO glass for dosimetry

    NASA Astrophysics Data System (ADS)

    Marini, Andrea; Valença, João V. B.; Oliveira, Raquel A. P.; Souza, Susana O.; Ciolini, Riccardo; d'Errico, Francesco

    2015-11-01

    Borate glasses are suitable for thermoluminescent dosimetry. In particular, borate glasses doped with different elements show good characteristics in terms of linearity, sensitivity and effective atomic number. However, these glasses are also hygroscopic, which can reduce their viability as dosimeters. In this work, the characteristics of borate glasses made with lithium and potassium oxides (LKB) were studied. To improve the glass features new formulations adding different amounts of magnesium oxide were developed. Mg improves the stability of the glasses since it reduces the mobility of the alkali ions and thus may reduce the hygroscopicity of the LKB glass. Three glass formulations containing 0, 5 and 11 mol% of magnesium oxide were produced by wet quenching method in order to determine the effect of Mg specifically on hygroscopicity and high-temperature resistance. The possibility to use this material for optically stimulated luminescence dosimetry was demonstrated. The LKB glass containing 11 mol% of Mg was found to withstand higher temperatures and to present the lower hygroscopicity compared to the other formulations.

  18. Electrical and optical properties of Ti doped ZnO films grown on glass substrate by atomic layer deposition

    SciTech Connect

    Wan, Zhixin; Kwack, Won-Sub; Lee, Woo-Jae; Jang, Seung-II; Kim, Hye-Ri; Kim, Jin-Woong; Jung, Kang-Won; Min, Won-Ja; Yu, Kyu-Sang; Park, Sung-Hun; Yun, Eun-Young; Kim, Jin-Hyock; Kwon, Se-Hun

    2014-09-15

    Highlights: • Ti doped ZnO films were prepared on Corning XG glass substrate by ALD. • The electrical properties and optical properties were systematically investigated. • An optimized Ti doped ZnO films had low resistivity and excellent optical transmittance. - Abstract: Titanium doped zinc oxide (Ti doped ZnO) films were prepared by atomic layer deposition methods at a deposition temperature of 200 °C. The Ti content in Ti doped ZnO films was varied from 5.08 at.% to 15.02 at.%. X-ray diffraction results indicated that the crystallinity of the Ti doped ZnO films had degraded with increasing Ti content. Transmission electron microscopy was used to investigate the microstructural evolution of the Ti doped ZnO films, showing that both the grain size and crystallinity reduced with increasing Ti content. The electrical resistivity of the Ti doped ZnO films showed a minimum value of 1.6 × 10{sup −3} Ω cm with the Ti content of 6.20 at.%. Furthermore, the Ti doped ZnO films exhibited excellent transmittance.

  19. Photo-acoustic spectroscopy and quantum efficiency of Yb3+ doped alumino silicate glasses

    NASA Astrophysics Data System (ADS)

    Kuhn, Stefan; Tiegel, Mirko; Herrmann, Andreas; Rüssel, Christian; Engel, Sebastian; Wenisch, Christoph; Gräf, Stephan; Müller, Frank A.; Körner, Jörg; Seifert, Reinhard; Yue, Fangxin; Klöpfel, Diethardt; Hein, Joachim; Kaluza, Malte C.

    2015-09-01

    In this contribution, we analyze the effect of several preparation methods of Yb3+ doped alumino silicate glasses on their quantum efficiency by using photo-acoustic measurements in comparison to standard measurement methods including the determination via the fluorescence lifetime and an integrating sphere setup. The preparation methods focused on decreasing the OH concentration by means of fluorine-substitution and/or applying dry melting atmospheres, which led to an increase in the measured fluorescence lifetime. However, it was found that the influence of these methods on radiative properties such as the measured fluorescence lifetime alone does not per se give exact information about the actual quantum efficiency of the sample. The determination of the quantum efficiency by means of fluorescence lifetime shows inaccuracies when refractive index changing elements such as fluorine are incorporated into the glass. Since fluorine not only eliminates OH from the glass but also increases the "intrinsic" radiative fluorescence lifetime, which is needed to calculate the quantum efficiency, it is difficult to separate lifetime quenching from purely radiative effects. The approach used in this contribution offers a possibility to disentangle radiative from non-radiative properties which is not possible by using fluorescence lifetime measurements alone and allows an accurate determination of the quantum efficiency of a given sample. The comparative determination by an integrating sphere setup leads to the well-known problem of reabsorption which embodies itself in the measurement of too low quantum efficiencies, especially for samples with small quantum efficiencies.

  20. Investigations on optical properties of Sm3+ ion doped boro-phosphate glasses

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K.

    2015-06-01

    The Sm3+ doped Boro-phosphate glasses with the chemical composition 60H3BO3+20Li2CO3+10ZnO+(10-x) H6NO4P+xSm2O3 (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach's energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm3+-Sm3+ ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.