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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. 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).

  3. 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.

  4. 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% V?O?-(80-x)% B?O?-20% Na?CO?) VBS glass system and (x%MnO?-(80-x)% B?O?-20% Na?CO?) 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 V?O? doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO? doped glass system (VBS glass system). The present study critically observes the doping of V?O? with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO?. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO? 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 Na?CO?, V?O? and MnO? 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

  5. Optical absorption and photoluminescence properties of Er3+ doped mixed alkali borate glasses.

    PubMed

    Ratnakaram, Y C; Kumar, A Vijaya; Naidu, D Tirupathi; Rao, J L

    2005-07-01

    An investigations of the optical absorption and fluorescence spectra of 0.2 mol% Er2O3 in mixed alkali borate glasses of the type 67.8B2O3 x xLi2O(32-x)Na2O, 67.8B2O3 x xLi2O(32-x)K2O and 67.8B2O3 x xNa2O(32-x)K2O (where x = 8, 12, 16, 20 and 24) are presented. The glasses were obtained by quenching melts consisting of H3BO3, Li2CO3, Na2CO3, K2CO3 and Er2O3 (950-1100 degrees C, 1.5-2 h) between two brass plates. Spectroscopic parameters like Racah (E1, E2 and E3), spin-orbit (xi(4f)) and configuration interaction (alpha) parameters are deduced as function of x. Using Judd-Ofelt theory, Judd-Ofelt intensity parameters (omega2, omega4 and omega6) are obtained. Radiative and non-radiative transition rates (A(T) and W(MPR)), radiative lifetimes (tauR), branching ratios (beta) and integrated absorption cross-sections (sigma) have been computed for certain excited states of Er3+ in these mixed alkali borate glasses. Emission spectra have been studied for all the three Er3+ doped mixed alkali borate glasses. The present paper throws light on the trends observed in the intensity parameters, radiative lifetimes, branching ratios and emission cross-sections as a function of x in these borate glasses, keeping in view the effect of mixed alkalies in borate glasses. PMID:15911407

  6. Rare earth-doped lead borate glasses and transparent glass-ceramics: structure-property relationship.

    PubMed

    Pisarski, W A; Pisarska, J; M?czka, M; Lisiecki, R; Grobelny, ?; Goryczka, T; Dominiak-Dzik, G; Ryba-Romanowski, W

    2011-08-15

    Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu(3+) and Er(3+) ions. The observed BO(3)?BO(4) conversion strongly depends on the relative PbO/B(2)O(3) ratios in glass composition, giving important contribution to the luminescence intensities associated to (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+). The near-infrared luminescence and up-conversion spectra for Er(3+) ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er(3+) ions into the orthorhombic PbF(2) crystalline phase, which was identified using X-ray diffraction analysis. PMID:21093353

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Luminescence spectra and structure of Er3+ doped alkali borate and fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Arul Rayappan, I.; Marimuthu, K.

    2013-11-01

    Trivalent erbium (Er3+) ion doped alkali borate and fluoroborate glasses were prepared and their structural and spectroscopic properties have been studied through XRD, FTIR, optical absorption and luminescence spectral measurements. The FTIR spectral studies reveal the presence of BO3, BO4 structural units and the strong OH- bonds in the title glasses. The absorption spectra were used to determine the bonding parameters (?¯,?) of the prepared glasses. Judd—Ofelt intensity parameters (??, ?=2, 4 and 6) have been calculated from the optical absorption spectra and are used to predict the important radiative properties like radiative transition probability (A), stimulated emission cross-section (?PE) and branching ratios (?R) for the excited state transitions such as 2H9/2?4I15/2 and 4S3/2?4I15/2 of the Er3+ ions in the prepared glasses. Optical band gap energy (Eopt) values through direct, indirect allowed transitions and the Urbach energy (?E) values of the prepared Er3+ glasses have also been determined and compared with similar studies. The spectral characteristics of the Er3+ ions due to compositional changes have been examined and reported in the present work.

  12. 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 (?cut-off), optical band gap (Eg), band tailing (B), Urbach energy (?E) 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%).

  13. Random lasing in Eu(3+) 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

    2015-10-01

    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

  14. 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.

  15. 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.

  16. 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 ?2, ?4 and ?6 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 ?2 parameter. PMID:25965518

  17. 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.

  18. Photon Interaction Parameters for Some Borate Glasses

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    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.

  19. 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.

  20. 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.

  1. 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 20CdO·xBi(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 (1150°C 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

  2. 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.

  3. 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 (??). The oscillator strengths and bonding parameters were determined from absorption spectra. The trend observed was ?4 > ?6 > ?2. High value of ?4 reveals higher rigidity and covalency around the Sm3+ ion. Low value of ?2 implies ionic nature of ligands and site symmetry around Sm3+ ion. luminescence data and Judd-Ofelt parameters ?? (? = 2, 4, and 6) were used to evaluate various radiative probabilities like spontaneous radiative emission probabilities (AR), radiative lifetime (?R) and branching ratios (?R) stimulated emission cross section (?e) 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.

  4. 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 xZnO?(30 - x)?Li2O?70B2O3 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.

  5. 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.

  6. 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}.

  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. The effect of Ce3+ ions on the spectral and decay characteristics of luminescence phosphate-borate glasses doped with rare-earth ions

    NASA Astrophysics Data System (ADS)

    Valiev, D. T.; Polisadova, E. F.; Belikov, K. N.; Egorova, N. L.

    2014-05-01

    The luminescent characteristics of Li2O-B2O3-P2O5-CaF2 (LBPC) glasses doped with Gd3+ and Tb3+ ions and codoped with Ce3+ are studied by pulsed optical spectrometry under electron beam excitation. It is found that in glass with Ce3+ and Gd3+ ions a decrease in the decay time of gadolinium luminescence in the 312-nm band (6 P J ? 8 S 7/2) was observed. It is shown that in the glass LBPC: Tb, Ce, an increase in the emission intensity in the main radiative transitions in terbium ion was observed. In the kinetics of luminescence band 545 nm of LBPC: Tb, Ce glasses, is present stage of buildup, the character of which changes with the doped of Ce3+ ions. The mechanism of energy transfer in LBP glasses doped with rare elements is discussed.

  9. 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

  10. 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.

  11. 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.

  12. 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 ?2, ?2 and ?12 are evaluated for Cu2+ doped samples. From the FTIR studies it was observed that the glass made up of BO3 and BO4 units.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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 ? 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.

  20. UNCORRECTED 2 Luminescence of erbium-doped bismuthborate glasses

    E-print Network

    Osnabrück, Universität

    UNCORRECTED PROOF 2 Luminescence of erbium-doped bismuth­borate glasses 3 Isabella-Ioana Oprea Received 26 May 2005; accepted 12 July 2005 7 Abstract 8 Absorption and luminescence properties of erbium for the composition range 25­65 mol% Bi2O3. A Judd­Ofelt analysis of the typical erbium bands in the absorption

  1. 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 (?) and the absorption cross section due to free carriers (?{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.

  2. 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.

  3. 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.

  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. 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.

  6. Ytterbium-doped borate fluoride laser crystals and lasers

    SciTech Connect

    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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).

  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. Medium-range order in cesium borate glasses probed by double-resonance NMR.

    PubMed

    Aguiar, Pedro M; Kroeker, Scott

    2005-01-01

    Rotational-echo double-resonance NMR is used to probe the proximity of Cs+ network modifiers to network-forming boron in binary cesium borate glasses. Low- and high-alkali glasses show distinctly different dephasing curves, which indicate preferential association of Cs+ with four-co-ordinate boron ([4]degrees )B) at low-alkali contents only. Different [4]B sites within a given glass appear to be subject to the same 133Cs dipolar field, thus placing constraints on the possible assignments of multiple tetrahedral boron peaks to different types of medium-range order and guiding future structural modeling studies. PMID:15589723

  13. Magnetic properties of cobalt-strontium-borate oxide glasses

    SciTech Connect

    Ardelean, I.; Ilonca, G.; Simon, S.; Filip, S.; Jurcut, T.

    1997-02-01

    The results of the temperature dependence of the magnetic susceptibility on xCoO{center_dot}(1 {minus} x)[2B{sub 2}O{sub 3}{center_dot}SrO] glasses with 0 < x {le} 50 mol% are reported. The effective magnetic moment values suggest that the Co{sup 2+} ions are predominantly octahedral coordinated in low CoO content glasses, whereas in higher CoO content glasses the Co{sup 2+} ions are located in tetrahedral sites. Also {theta}{sub p} values indicate that the Co{sup 2+} ions participate at the negative superexchange interaction for x {ge} 20 mol%.

  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. 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 ?m 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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 (1?m) 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

  3. 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.

  4. 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

  5. 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.; Pédrini, 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).

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

    NASA Astrophysics Data System (ADS)

    Haumesser, Paul-Henri; Gaumé, Romain; Benitez, Jean-Marie; Viana, Bruno; Ferrand, Bernard; Aka, Gérard; 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.

  7. Characterisation and luminescence studies of Tm and Na doped magnesium borate phosphors.

    PubMed

    Ekdal, E; Garcia Guinea, J; Karabulut, Y; Canimoglu, A; Harmansah, C; Jorge, A; Karali, T; Can, N

    2015-09-01

    In this study, structural and luminescence properties of magnesium borate of the form MgB4O7 doped with Tm and Na were investigated by X-ray diffraction (XRD), Raman spectroscopy and cathodoluminescence (CL). The morphologies of the synthetised compounds exhibit clustered granules and road-like materials. As doping trivalent ions into a host with divalent cations requires charge compensation, this effect is discussed. The CL spectra of undoped MgB4O7 shows a broad band emission centred around 350 nm which is postulated to be produced by self-trapped excitons and some other defects. From the CL emission spectrum, main emission bands centred at 360, 455, 475 nm due to the respective transitions of (1)D2?(3)H6,(1)D2?(3)F4 and (1)G4?(3)H6 suggest the presence of Tm(3+) ion in MgB4O7 lattice site. CL mechanism was proposed to explain the observed phenomena which are valuable in possibility of the developing new luminescent materials for different applications. In addition, the experimental Raman spectrum of doped and undoped MgB4O7 were reported and discussed. PMID:26072018

  8. 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.

  9. 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.

  10. 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.

  11. 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 ?6 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.

  12. 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.

  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. Dysprosium (III)-doped novel silicate glasses

    NASA Astrophysics Data System (ADS)

    Stara-Janakova, Stanislava; Spirkov, Jarmila; Mika, Martin; Oswald, Jiri

    2009-11-01

    Dysprosium-doped optical materials are currently becoming a matter of interest mainly for their utilisation in the MIR spectral region. We report here on specially designed dysprosium-doped silicate glasses, whose optical properties were characterised by VIS and NIR measurements of their absorption and transmission spectra. The planar waveguides were fabricated in these glasses employing Ag + and K + ion exchange (IE), and their optical properties were ascertained by dark mode spectroscopy. The chemical compositions of the exchanged layers were determined using electron microscope analysis (EMA), where the effect of the bivalent glass modifiers (such as Ca 2+, Mg 2+ and Zn 2+ and their mixtures) in the glass matrix on the properties of the exchanged layers - both chemical (with different permeabilities of the matrix for diffusing ions) and optical (waveguiding) were examined. The role of bivalent modifiers in the permeability of the glasses has been described and explained on the basis of the concept of optical basicity. The relations yielding a guideline to specify the contributions of the particular modifiers to the resultant depths of the IE layers have been suggested as well.

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

    NASA Astrophysics Data System (ADS)

    Alvarez, E. R.; Camarillo, I. G.; Castaño, E. T.; Muñoz, 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.

  16. 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

  17. 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.

  18. 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

  19. Journal of Luminescence 122123 (2007) 1416 Femtosecond laser-induced reduction in Eu-doped sodium

    E-print Network

    Hamilton, Douglas S.

    2007-01-01

    Journal of Luminescence 122­123 (2007) 14­16 Femtosecond laser-induced reduction in Eu-doped sodium of Eu3+ to Eu2+ in sodium borate glasses by irradiation of near-infrared femtosecond laser. Glass composition of sodium borate was 85B2O3­15Na2O. The glasses were doped with 0.05, 0.1, and 0.5mol% Eu2O3

  20. 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

  1. 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??m 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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.

  3. 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)

  4. Doping method to glass material using a CO2 laser

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Tamaki, T.

    2013-03-01

    In this paper, we present the investigation results on doping to a BK7 glass sample ( OHARA, S-BSL7 ) by use of a CO2 laser. CO2 laser system generates CW ( continuous wave ) laser beam with a wavelength of 10.6 ?m. Laser beam irradiated on a sample substrate ( 30 mm × 5 mm × 0.67 mm thick ). A surface of the glass was applied fluorescent material. The doped regions were created by translating the glass sample perpendicular to the laser axis with a distance of 2 mm and a scan speed of 1 mm/s. After processing, the cross section of sample was analyzed by energy dispersive X-ray analysis ( EDX ) in scanning electron microscope for revealing the contained elements in the glass. The results show that carbon was widely distributed in the doped regions although the original glass material did not contain carbon element.

  5. Multiphasic nanostructured composites for photonics: Fullerene-doped monolith glass

    SciTech Connect

    Gvishi, R.; Bhawalkar, J.D.; Kumar, N.D.; Ruland, G.; Narang, U.; Praasad, P.N.

    1995-11-01

    The authors prepared nanostructured composite materials via sol-gel methods where doping of either C{sub 60} or bisbenzothiazole 3,4-didecyloxythiophene (BBTDOT) was employed. A multiphasic composite glass doped with both C{sub 60} and BBTDOT displayed significant optical power at 532 and 800 nm due to independent limiting effects of each dopant. 31 refs., 4 figs.

  6. Characterization of new erbium-doped tellurite glasses and fibers

    E-print Network

    Dierolf, Volkmar

    Tellurite glasses are promising candidates for optical fiber laser and amplifier applications because durability make them promising candidates for fiber laser and optical amplifier applications [1-doped fiber amplifiers (EDFA) for the C and L bands, thulium-doped fiber amplifiers (TDFA) for the S

  7. 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.

  8. Photoinduced phenomena in chalcogenide glasses doped with metals

    E-print Network

    Boolchand, Punit

    on relaxation of photodarkening in a-As2Se3 doped with Sn and rare-earth (RE) ions (Dy, Pr, Hon, Sm3 Nd, Er3 for chalcogenide glasses doped with rare-earth ions as perspective materials for fibre optics amplifiers operating and the kinetics ofphotodarkening in amonhous As2Se3:Sn thin films at %) and and AsSe3 doped with rare-earth ions

  9. 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

  10. Orange emission in Pr3+-doped fluoroindate glasses

    E-print Network

    Manzani, Danilo; Ribeiro, Sidney J L; Goldner, Philippe; Bretenaker, Fabien

    2012-01-01

    We synthesize and study the properties of praseodymium doped fluoroindate glasses. Glass compositions with praseodymium molar concentrations up to 5% were obtained with good optical quality. Thermal, optical, and luminescence properties are investigated. Judd-Ofelt analysis is used to determine radiative lifetime and emission cross-section of the orange transition originating from the 3P0 level. We find that these glasses are good candidates for the realization of blue diode laser pumped orange lasers for quantum information processing applications.

  11. 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 ?{sub 2}, ?{sub 4} and ?{sub 6} parameters. Radiative properties like branching ratio ?{sub r} and the radiative life time ?{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+}.

  12. 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.

  13. 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.

  14. 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 (?) and bonding parameter (?) 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 (?2, ?4 and ?6) were calculated with the application of JO theory and the trends of the JO intensity parameters are found to be ?2>?6>?4 for all the prepared glasses with a minimum variation in ?2 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 (?P(E)), branching ratio (?r) and radiative lifetime (?) 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

  15. [Spectroscopic properties of Er3+-doped germanium bismuthate glass].

    PubMed

    Zhang, Yong; Ren, Guo-Zhong; Yang, Qi-Bin; Xu, Chang-Fu; Liu, Yun-Xin; Shang, Zhen-Gang

    2008-05-01

    Er(3+)-Doped Germanium Bismuthate Glass was fabricated and characterized. The absorption spectrum and up-conversion spectrum of glass were studied. The Judd-Oflet intensity parameters omega(t) (t = 2, 4, 6), determined based on Judd-Ofelt theory, were found to be omega2 = 3.35 x 10(-20) cm2, omega4 = 1.34 x 10(-20) cm2, omega6 = 0.67 x 10(-20) cm2. Frequency up-conversion of Er(3+)-doped germanium bismuthate glass has been investigated. The up-conversion mechanisms are discussed under 808 nm and 980 nm excitation. Stimulated emission cross-section of 4I(13/2) --> 4I(15/2) transition was calculated by McCumber theory. Compared to other host glasses, the emission property of Er(3+)-doped germanium bismuthate glasses has advantage over those of silicate, phosphate and germinate glasses. Er(3+)-doped germanium bismuth glasses are promising upconversion optical and optic-communication materials. PMID:18720787

  16. 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.

  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. 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).

  19. 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.

  20. 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.

  1. 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.

  2. 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

    2015-01-01

    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 ?-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 ?-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

  3. 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.

  4. 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.

  5. 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.

  6. 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 ?2>?4>?6 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.

  7. 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.

  8. 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.

  9. Evaluating displacement damage in cerium-doped yttrium borate using photoluminescence lifetime

    NASA Astrophysics Data System (ADS)

    Gollub, S. L.; Mitchell, C. A.; Rogers, B. R.; Walker, D. G.

    2015-07-01

    The photoluminescence lifetime and spectrum of YBO3:Ce3+ are observed before and after proton bombardment. The optical properties change under irradiation, and thus the material can record information about the radiation exposure. As the fluence of 1 MeV protons increases beyond 1014proton/cm2, the lifetime of YBO3:Ce3+ decreases nearly exponentially. Furthermore, by changing the concentration of cerium, the sensitivity of the material to the radiation induced defects is controllable such that lower-doped YBO3:Ce3+ is more sensitive to damage.

  10. 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.

  11. Synthesis and spectroscopic studies of Fe3+-doped zinc borate powder

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    Fe3+-doped Zn3(BO3)2 powder is synthesized using a co-precipitation method. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), optical absorption, electron paramagnetic resonance (EPR), photoluminescence (PL), and Fourier transformation infrared (FTIR) spectroscopy were used to analyze the synthesized sample. The PXRD patterns confirm the monoclinic structure of the as-prepared sample. SEM images reflect the surface morphology of the sample. Energy dispersive X-ray spectroscopy (EDX) data confirms the presence of dopant ions in the host lattice. Crystal field (Dq) and inter-electronic repulsion (B and C) parameters were evaluated. The EPR spectrum shows two resonance signals, at g = 2.12 and 4.36. This indicates the existence of Fe3+ ions in tetragonally distorted octahedral site symmetry. The PL spectrum shows ultraviolet emission at room temperature. FT-IR spectroscopy confirms the fundamental vibrational bands of host molecules.

  12. 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.

  13. 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.

  14. 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 ?-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.

  15. 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

  16. 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)

  17. 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.

  18. Spectral luminescence characteristics of forsterite nano glass ceramics doped with chromium ions

    NASA Astrophysics Data System (ADS)

    Aseev, V. A.; Zhukov, S. N.; Kuleshov, N. V.; Kuril'chik, S. V.; Mudryi, A. V.; Nikonorov, N. V.; Rokhmin, A. S.; Yasyukevich, A. S.

    2015-01-01

    A technology for production of nano-glass-ceramic materials based on aluminosilicate glass doped with chromium oxide is proposed. A comparative study of the spectral luminescence properties of forsterite glass ceramics and single crystal doped with chromium ions is performed. It is shown that chromium ions are partially incorporated into the glass-ceramics crystalline phase. The quantum luminescence yields of Cr4+ ions in forsterite nano glass ceramics and single crystal are found to be close.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Blocking effect of crystal–glass interface in lanthanum doped barium strontium titanate glass–ceramics

    SciTech Connect

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

    2013-10-15

    Graphical abstract: The blocking effect of the crystal–glass interface on the carrier transport behavior in the lanthanum doped barium strontium titanate glass–ceramics: 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 crystal–glass interface impedance increases. • La{sub 2}O{sub 3} addition increases blocking factor of the crystal–glass interface. - Abstract: The microstructures and dielectric properties in La{sub 2}O{sub 3}-doped barium strontium titanate glass–ceramics 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 crystal–glass interface impedance becomes larger. More interestingly, it was found that La{sub 2}O{sub 3} additive increases blocking factor of the crystal–glass interface in the temperature range of 250–450 °C. This may be attributed to a decrease of activation energy of the crystallite and an increase of the crystal–glass interface area.

  4. Pr 3+-doped ZBLA fluoride glasses for visible laser emission

    NASA Astrophysics Data System (ADS)

    Olivier, Melinda; Pirasteh, Parastesh; Doualan, Jean-Louis; Camy, Patrice; Lhermite, Hervé; Adam, Jean-Luc; Nazabal, Virginie

    2011-05-01

    Praseodymium doped Fluoride glasses were studied in order to fabricate compact solid state laser sources emitting in the visible range for lighting application and for quantum information processing. The objective of this study is focused on red, green and orange emissions. ZBLA bulk glasses (57%ZrF 4 - 34%BaF 2 - (5 - x)%LaF 3 - 4%AlF 3 - x%PrF 3) have been synthesized under dry argon atmosphere. Physicochemical and optical properties such as density, glass transition temperature, composition, transmission and refractive index have been investigated. Spectroscopic studies have been performed to optimize the rare earth doping level in order to reach the best compromise respecting a good optical quality, a highest lifetime and efficient emission intensity at 635, 605 and 520 nm. Spectroscopic measurements have been carried out on bulk samples with Pr 3+ concentrations ranging from 0.1 to 3 mol% and first characterizations of ion exchanged Pr: ZBLA waveguides are reported.

  5. Surface silver-doping of biocompatible glass to induce antibacterial properties. Part I: Massive glass.

    PubMed

    Verné, E; Miola, M; Vitale Brovarone, C; Cannas, M; Gatti, S; Fucale, G; Maina, G; Massé, A; Di Nunzio, S

    2009-03-01

    A glass belonging to the system SiO(2)-Al(2)O(3)-CaO-Na(2)O has been subjected to a patented ion-exchange treatment to induce surface antibacterial activity by doping with silver ions. Doped samples have been characterized by means of X-Ray diffraction (XRD), scanning electron microscopy (SEM) observation, energy dispersion spectrometry (EDS) analysis, in vitro bioactivity test, Ag(+) leaching test by graphite furnace atomic absorption spectroscopy (GFAAS) analyses, cytotoxicity tests by fibroblasts adhesion and proliferation, adsorption of IgA and IgG on to the material to evaluate its inflammatory property and antibacterial tests (cultures with Staphylococcus aureus and Escherichia coli). In vitro tests results demonstrated that the modified glass maintains the same biocompatibility of the untreated one and, moreover, it acquires an antimicrobial action against tested bacteria. This method can be selected to realize glass or glass-ceramic bone substitutes as well as coatings on bio-inert devices, providing safety against bacterial colonization thus reducing the risks of infections nearby the implant site. The present work is the carrying on of a previous research activity, concerning the application of an ion-exchange treatment on glasses belonging to the ternary system SiO(2)-CaO-Na(2)O. On the basis of previous results the glass composition was refined and the ion-exchange process was adapted to it, in order to tune the final material properties. The addition of Al(2)O(3) to the original glass system and the optimization of the ion-exchange conditions allowed a better control of the treatment, leading to an antibacterial material, without affecting both bioactivity and biocompatibility. PMID:18987954

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

    E-print Network

    Hughes, M; Rutt, H; Hewak, D

    2014-01-01

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

  7. 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.

  8. Fullerene doped glasses Fucheng Lin, Sen Mao, Zhicong Meng, and Heping Zeng

    E-print Network

    Guo, Ting

    Fullerene doped glasses Fucheng Lin, Sen Mao, Zhicong Meng, and Heping Zeng Shanghai Institute 1994; accepted for publication 15 September 1994 Optical glasses doped with a fullerene mixture of C60/C70 were made in our lab. Three peaks, corresponding to C60, C70, and a modified fullerene possibly

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

    NASA Astrophysics Data System (ADS)

    Jiménez, José 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.

  10. 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.

  11. 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.

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

    NASA Astrophysics Data System (ADS)

    Narro-García, R.; Desirena, H.; López-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%.

  13. 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.

  14. Field-assisted solid state doping of glasses for optical materials

    NASA Astrophysics Data System (ADS)

    Quaranta, A.; Cattaruzza, E.; Gonella, F.; Peruzzo, G.; Giarola, M.; Mariotto, G.

    2010-08-01

    Field-assisted solid-state ion-exchange (FASSIE) allows the doping of surface glass layers with multivalent ions which could not diffuse into the glass matrix by the usual thermal ion-exchange process in molten salt baths. This paper presents preliminary spectroscopic investigation of the diffusion of chromium in silicate glasses, with the aim at improving the procedures for the production of Cr-doped optical waveguides. Metallic chromium films deposited onto the glass substrates by the rf-sputtering technique were used as metal ions source. The environment of diffused chromium ions into the glass matrix was investigated by means of micro-Raman spectroscopy.

  15. 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.

  16. Laser beam irradiation of silver doped silicate glasses

    NASA Astrophysics Data System (ADS)

    Trave, E.; Gonella, F.; Calvelli, P.; Cattaruzza, E.; Canton, P.; Cristofori, D.; Quaranta, A.; Pellegrini, G.

    2010-10-01

    Planar light waveguides prepared by Ag-Na ion exchange in molten salt bath are irradiated with Nd:YAG laser beams at different wavelengths in the IR and VIS regions, and for different energy density and repetition rate values. The samples are characterized by optical spectroscopy to determine the role of irradiation parameters in the Ag clustering process, including aggregation phenomena and possible cluster photofragmentation. The appearance of the characteristic plasmon resonance feature in the optical absorption spectra marks the formation of Ag clusters, as observed by electronic microscopy as well, and permits to follow the evolution of the whole clustering process upon increasing of the deposited energy density. Photoluminescence spectroscopy has given specific information concerning the presence of Ag multimeric aggregates, considered as embryonic structures for the growing nanoclusters. The systematic investigation presented in this work is expected to clarify some aspects of the interaction between the laser beam and the doped glass matrix, and to help establishing suitable methodologies for the controlled preparation of nanocomposite glasses.

  17. Enhanced emissions in Tb3+-doped oxyfluoride scintillating glass ceramics containing BaF2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Huang, Lihui; Jia, Shijie; Li, Yang; Zhao, Shilong; Deng, Degang; Wang, Huanping; Jia, Guohua; Hua, Youjie; Xu, Shiqing

    2015-07-01

    Transparent Tb3+-doped glass ceramics containing BaF2 nanocrystals were prepared by melt-quenching method with subsequent heat treatment. The XRD and EDS results showed the precipitated crystalline phase in the glass matrix was BaF2. Under 376 nm light, Tb3+ doped oxyfluoride glass ceramics containing BaF2 nanocrystals showed more intense green emission than the as-made glass, and the emission intensity increased with increasing heat treatment temperature and time. The lifetimes of 541 nm emission of Tb3+ doped oxyfluoride glass ceramics were longer than that of as-made glass, which are in the range from 3.00 ms to 3.55 ms. Under X-ray excitation, the green emission was enhanced in the glass ceramics compared to the as-made glass. The results indicate Tb3+ doped oxyfluoride glass ceramics containing BaF2 nanocrystals could be a material candidate for X-ray glass scintillator for slow event detection.

  18. 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 280°C 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.

  19. 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.

  20. 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; Vernè, 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

  1. 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.

  2. Fluorescence characteristics and energy transfer of ytterbium-sensitized erbium-doped fluorophosphate glass for amplifier applications

    NASA Astrophysics Data System (ADS)

    Tian, Ying; Wei, Tao; Chen, Fangze; Jing, Xufeng; Zhang, Junjie; Xu, Shiqing

    2014-01-01

    Yb3+/Er3+ codoped fluorophosphate glass has been investigated for developing broadband waveguide amplifier application. Spectroscopic properties and energy transfer microparameters of prepared glasses have been discussed. The spectral components of 1.55 ?m emission are analyzed and an equivalent four-level system is proposed to estimate the stark splitting for the 4I15/2 and 4I13/2 levels in Er3+ doped fluorophosphate glass. The results indicate that highly doped Yb3+ ions could transfer energy to Er ions efficiently in fluorophosphate glass and Er3+/Yb3+ doped fluorophosphate glass is preferable for broadband Er3+-doped waveguide amplifier application.

  3. 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)

  4. 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.

  5. Local-field approximation of homonuclear dipolar interactions in ?Li-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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Advances in laser cooling of thulium-doped glass C. W. Hoyt, M. P. Hasselbeck, and M. Sheik-Bahae

    E-print Network

    Sheik-Bahae, Mansoor

    suggested that rare-earth-doped crystals might provide a medium for solid-state cooling resulting from anti December 9, 2002 Recent developments in cooling thulium-doped heavy-metal fluoride glass are presented

  11. Fictive temperature dependences of optical properties in Yb-doped silica glass

    NASA Astrophysics Data System (ADS)

    Saito, K.; Yamamoto, R.; Kamiya, N.; Sekiya, E. H.; Barua, P.

    2008-04-01

    Correlation between Yb 3+ optical properties and structural disorder of glass network has been investigated by using good quality Yb-doped silica glasses fabricated by MCVD method. Absorption spectra strongly depend on the fictive temperature, which is a good indicator of structural disorder in silica glass. Their dependences are affected by the codopants (Al and F). Fictive temperature dependence of refractive index has been also elucidated.

  12. Low-threshold lasing at 1975??nm in thulium-doped tellurite glass microspheres.

    PubMed

    Vanier, Francis; Côté, François; Amraoui, Mohammed El; Messaddeq, Younès; 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 106 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

  13. 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.

  14. 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.

  15. Broadband near-infrared emission from transparent Ni{sup 2+}-doped silicate glass ceramics

    SciTech Connect

    Zhou Shifeng; Dong Huafang; Zeng Heping; Wu Botao; Zhu Bin; Yang Hucheng; Xu Shiqing; Wan Zhiyu; Qiu Jianrong

    2007-09-15

    Transparent Ni{sup 2+}-doped MgO-Al{sub 2}O{sub 3}-TiO{sub 2}-SiO{sub 2} glass ceramics were prepared, and the optical properties of Ni{sup 2+}-doped glass ceramics were investigated. Broadband emission centered at 1320 nm was observed by 980 nm excitation. The longer wavelength luminescence compared with Ni{sup 2+}-doped Li{sub 2}O-Ga{sub 2}O{sub 3}-SiO{sub 2} glass ceramics is ascribed to the low crystal field hold by Ni{sup 2+} in MgO-Al{sub 2}O{sub 3}-TiO{sub 2}-SiO{sub 2} glass ceramics. The change in optical signals at the telecommunication bands with or without 980 nm excitation was also measured when the seed beam passes through the bulk gain host.

  16. Study on the laser-induced darkening in Nd-doped laser glasses

    NASA Astrophysics Data System (ADS)

    Zhou, Qinling; Xu, Lei; Liu, Liying; Wang, Wencheng; Zhu, Congshan; Gan, Fuxi

    2004-04-01

    Laser induced darkening in the soda-lime silicate (15Na 2O · 15CaO · 70SiO 2) based glass and type N 31 barium metaphosphate Ba(PO 3) 2 based glass were studied by exposing the glass samples in frequency-quadrupled Nd:YAG (266 nm, 5 ns) laser and Ti:Sapphire (800 nm, 120 fs) laser. Both types of the glasses were doped with Nd 2O 3 at doping levels less than 3 wt%. Hole center HC 1 formed after UV laser exposure in soda-lime silicate based laser glass, and both HC 1 hole center and SiE ' center formed in it after IR fs laser irradiation. In phosphate glass, UV ns laser and IR fs laser generated the same types of color centers, intermediate structure of oxygen ions type II and type III. The experimental results also showed that the soda-lime silicate laser glass is easier to be darkened than the phosphate glass, irradiated by either 266 nm UV laser or fs laser. While free electrons from single photon ionization is considered to be the main cause of defect formation in glasses irradiated by nanosecond UV laser, rapid cooling of the melted glasses heated by energetic electrons generated from multi-photon and avalanche ionization should be the causes of defect formation in glasses irradiated by fs laser.

  17. Spectroscopic properties of Er3+-doped glasses for the realization of active waveguides by ion-exchange technique

    NASA Astrophysics Data System (ADS)

    Cognolato, Livio; De Bernardi, Carlo S.; Ferraris, Monica; Gnazzo, Angelantonio; Morasca, Salvatore; Scarano, Domenica

    1991-08-01

    The fabrication of different types of Er3+-doped glasses and the study of their absorption and emission spectra, cross sections, lifetimes, and bandwidths are described. The purpose is to get guidelines for the synthesis of the appropriate glasses to manufacture active planar waveguides. The feasibility of active integrated optical waveguides by ion-exchange on these glasses is also demonstrated, using an Er3--doped soda-lime glass.

  18. Short vertical tube furnace for the fabrication of doped glass microsphere lasers.

    PubMed

    Ward, Jonathan M; Wu, Yuqiang; Khalfi, Krimo; Nic Chormaic, Síle

    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 approximately 1 microm diameter are blown into the furnace using a 60 ml syringe and microspheres ranging in size from 10 to 400 microm are collected at the output of the tube furnace in a Petri dish. The furnace operates at a wall temperature of approximately 900 degrees C and is capable of making microspheres from glasses with glass transition temperatures of at least 375 degrees C. High quality (Q approximately 10(5)) whispering gallery modes have been excited within the microspheres by optically pumping at 978 nm via a tapered optical fiber. PMID:20687704

  19. Nanodiamond in tellurite glass Part II: practical nanodiamond-doped fibers

    E-print Network

    Ruan, Yinlan; Johnson, Brett C; Ohshima, Takeshi; Greentree, Andrew D; Gibson, Brant C; Monro, Tanya M; Ebendorff-Heidepriem, Heike

    2014-01-01

    Tellurite glass fibers with embedded nanodiamond are attractive materials for quantum photonics applications. Reducing the loss of these fibers in the 600-800 nm wavelength range of nanodiamond fluorescence is essential to exploit the unique properties of nanodiamond in the new hybrid material. The first part of this study reported the origin of loss in nanodiamond-doped glass and impact of glass fabrication conditions. Here, we report the fabrication of nanodiamond-doped tellurite fibers with significantly reduced loss in the visible through further understanding of the impact of glass fabrication conditions on the interaction of the glass melt with the embedded nanodiamond. We fabricated tellurite fibers containing nanodiamond in concentrations up to 0.7 ppm-weight, while reducing the loss by more than an order of magnitude down to 10 dB/m at 600-800 nm.

  20. Study of structural and spectral properties of neodymium-doped lead-yttrium oxyfluoride nano-glass-ceramics

    NASA Astrophysics Data System (ADS)

    Bibik, A. Yu.; Nuryev, R. K.; Aseev, V. A.; Kolobkova, E. V.; Nikonorov, N. V.

    2015-06-01

    Processes of nanocrystalline phase formation in transparent yttrium oxyfluoride nano-glass-ceramics doped with neodymium ions are studied. An optimal heat treatment regime for a given glass composition is determined using differential thermal analysis (DTA). Glasses are heat-treated for 30, 60, and 120 min; the sizes of crystals are calculated, and the unit cell parameters are determined. The physicochemical and spectral properties of yttrium oxyfluoride glasses doped with neodymium ions, as well as of nano-glass-ceramics based on these glasses, are studied.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Lead-gallium glasses and glass-ceramics doped with SiO2 for near infrared transmittance

    NASA Astrophysics Data System (ADS)

    Marczewska, Agnieszka; ?roda, Marcin; Nocu?, Marek; Sulikowski, Bogdan

    2015-07-01

    Lead-gallium glasses, due to the absence of typical glass-forming components, are characterized by an increased tendency to crystallization. Despite this, they are interesting materials due to a shift of IR absorption edge up to 6-7 ?m. The paper considers how the SiO2 dopant affects thermal stability and the UV-VIS and IR transmittance of lead-gallium glasses. The base lead-gallium glass (0.75PbO·0.25Ga2O3) was modified by the addition of 5, 10 and 15 mol% SiO2, respectively. DTA/DSC data showed that the glasses are characterized by the multi-stage crystallization, which is changed with the amount of silica doped. The XRD analysis confirmed that: (i) different forms of lead oxide crystallize after heat treatment of the glass, and (ii) the Ga2PbO4 phase is formed at higher temperatures. The silica admixture allowed inserting a few percent of BaF2 into the lead-gallium glass structure. It was found that a transparent glass-ceramic based on the lead-gallium glass with a low phonon barium fluoride phase can be obtained during the thermal treatment. The study of UV-VIS-IR transmittance shows that 10-15 mol% SiO2 in the lead-gallium glasses diminishes the absorption band in the range of 2.6-4 ?m due to the presence of hydroxyl groups and simultaneously reduces transmittance in the range of 5-6.5 ?m from 10 to 20%. Introduction of SiO2 to the glass results in the increase of transmittance in the shorter wavelength region and the UV-edge shift is observed. It was also confirmed that the BaF2 nanocrystallites exert no effect on the transmittance of the spectrum analyzed.

  6. Tm3+ doped Ga-As-S chalcogenide glasses and fibers

    NASA Astrophysics Data System (ADS)

    Galstyan, A.; Messaddeq, S. H.; Fortin, V.; Skripachev, I.; Vallée, 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.

  7. Photometric sensors based on sol-gel porous glass doped with organic reagents

    NASA Astrophysics Data System (ADS)

    Lev, Ovadia; Kuyavskaya, B. I.; Sacharov, Y.; Rottman, Claudio; Kuselman, A.; Avnir, David; Ottolenghi, M.

    1993-03-01

    A new class of sensitive disposable sensors for determination of trace concentrations of water pollutants has been developed. It utilizes porous transparent silica glasses doped with organic photometric reagents. The silica sensors are produced at room temperature by the sol-gel procedure, i.e. by hydrolysis followed by polycondensation of tetraalkoxysilanes. Thus, we produced porous glasses doped with organic photometric reagents for the determination of typical cations, anions, pH, oxidation agents (e.g. disinfection agents) as well as typical air pollutants. A mathematical model for a flat plate monolithic iron sensor was developed and the predicted calibration curves were compared with the experimental response.

  8. Structure and spectroscopic properties of Er3+ doped germanate glass for mid-infrared application

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Chen, Fangze; Jing, Xufeng; Wang, Fengchao; Tian, Ying; Xu, Shiqing

    2014-05-01

    Intense 2.7 ?m emission derived from modified Er3+ doped germanate glass was reported. Raman spectrum analysis was carried out to grasp glass structure. Based on the absorption spectrum, the Judd-Ofelt parameters and radiative properties were calculated originated from Judd-Ofelt theory. 2.7 ?m emission characteristics, stark splitting features and energy transfer processes upon excitation of a conventional 808 nm or 980 nm laser diode were carefully investigated. The prepared glass possesses high spontaneous transition probability (34.28 s-1), large calculated emission cross section (13 × 10-21 cm2) and gain coefficient (5.4 cm-1) for the 4I11/2 ? 4I13/2 transition. These results indicate that Er3+ doped germanate glass has potential applications in mid-infrared lasers and amplifiers.

  9. Thermal stability and spectroscopic properties of Er3+-doped antimony-borosilicate glasses.

    PubMed

    Qian, Q; Zhao, C; Yang, G F; Yang, Z M; Zhang, Q Y; Jiang, Z H

    2008-11-01

    This paper reports on the optical spectroscopic properties and thermal stability of Er3+-doped antimony-borosilicate glasses for developing 1.5 microm optical amplifiers. Upon excitation at 980 nm laser diode, an intense 1.5 microm infrared fluorescence has been observed with the maximum full width at half maximum (FWHM) of 90 nm for Er3+-doped antimony-borosilicate glasses. The emission cross-section and the lifetime of the 4I13/2 level of Er3+ ions are 6.3 x 10(-21) cm2 and 0.30 ms, respectively. It is noted that the product of the emission cross-section and FWHM of the glass studied is as great as 567 x 10(-21) cm2 nm, which is comparable or higher than that of bismuthate and tellurite glasses. PMID:18255334

  10. 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.

  11. 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.

  12. Spectroscopic properties and energy transfer parameters of Er3+-doped fluorozirconate and oxyfluoroaluminate glasses.

    PubMed

    Huang, Feifei; Liu, Xueqiang; Hu, Lili; Chen, Danping

    2014-01-01

    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. PMID:24852112

  13. 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.

  14. Radiation hardening in sol-gel derived Er3+-doped silica glasses

    NASA Astrophysics Data System (ADS)

    Hari Babu, B.; Ollier, Nadège; León Pichel, Mónica; 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.

  15. 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 45±10 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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 980cm(-1), while they decrease that of BO2O(-) groups at 1440-1470cm(-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 8weeks 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

  1. Microstructure and luminescence of Yb{sup 3+}-doped fluorosilicate glass ceramics

    SciTech Connect

    Qiao, Xvsheng; Fan, Xianping; Pan, Yu; Lotnyk, Andriy; Kienle, Lorenz

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Fine nano-SrF{sub 2} lattices were observed in the fluorosilicate glass ceramics. Black-Right-Pointing-Pointer EDXS analysis showed Yb{sup 3+} was enriched into the SrF{sub 2} nanocrystals. Black-Right-Pointing-Pointer That deduced intense cooperative luminescence of the glass ceramics. Black-Right-Pointing-Pointer NIR emissions appeared large bandwidths and long lifetimes simultaneously. Black-Right-Pointing-Pointer Yb{sup 3+} can be an efficient upconversion sensitizer or NIR activator in this host. -- Abstract: Yb{sup 3+}-doped transparent glass ceramics containing cubic SrF{sub 2} nanocrystals were prepared by heat treating the precursor fluorosilicate glass. The precipitated crystals increase in size and the crystallinity decreases with increasing Yb{sup 3+} doping level. With high-resolution transmission electron microscopy and electron diffraction, the nano-sized nature of SrF{sub 2} was clearly observed. Owing to a significant change in the crystal-field effects with Yb{sup 3+} enriching in the SrF{sub 2} phase, the glass ceramics present near infrared emission with large bandwidths and long lifetimes, simultaneously. This indicates the glass ceramics have potential application in the efficient IR lasers pumping by InGaAs diodes. The glass ceramics can also emit blue upconversion luminescence, deriving from Yb{sup 3+} pairs' cooperative luminescence. It suggested that Yb{sup 3+} can be an efficient upconversion sensitizer for other rare earth ions.

  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. 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.

  4. 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.

  5. Spectroscopic properties and external quantum yield of Sm3+ doped germanotellurite glasses

    NASA Astrophysics Data System (ADS)

    Wang, F.; Chen, B. J.; Lin, H.; Pun, E. Y. B.

    2014-11-01

    Sm3+ doped germanotellurite glasses (NZPGT) with maximum phonon energy of 793 cm-1 have been prepared and characterized. Judd-Ofelt parameters ?t (t=2, 4, 6) have been calculated to be 3.52×10-20, 4.70×10-20 and 1.90×10-20 cm2, respectively. Large value of ?2 indicates a high asymmetry and covalent environment around Sm3+ in the glass system. The maximum stimulated emission cross-section of the dominant transition 4G5/2?6H9/2 peaking at 645.0 nm was derived to be 10.00×10-22 cm2, predicting that the red fluorescence emission can be efficiently extracted from the optical glasses. The internal quantum efficiency and external quantum yield of 0.4 wt% Sm2O3 doped NZPGT glasses were deduced to be 82.5% and 6.0%, respectively. The results demonstrate that Sm3+ doped NZPGT glasses are a potential candidate for developing tunable visible lasers, compact light sources and solid-state display devices.

  6. Structural studies of lithium boro tellurite glasses doped with praseodymium and samarium oxides

    SciTech Connect

    Damas, Pedro; Coelho, João; 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.

  7. 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 µm fluorescence characteristics were investigated and it was found that the effective 2.7 µm emission bandwidth can reach to 101.79 nm in prepared glasses. The tunability of the 2.7 µm 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

  8. 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

  9. 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}–24LiF–23SrF{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. Judd–Ofelt (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.

  10. 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

  11. White luminescence of Tm-Dy ions co-doped aluminoborosilicate glasses under UV light excitation

    SciTech Connect

    Liu Shimin; Zhao Gaoling; Lin Xiaohua; Ying Hao; Liu Junbo; Wang Jianxun; Han Gaorong

    2008-10-15

    Tm{sup 3+} and Dy{sup 3+} ions co-doped aluminoborosilicate glasses were prepared in this study. The luminescence properties of the glasses were analyzed. A combination of blue, green, yellow, and red emission bands was shown for these glasses, and white light emission could be observed under UV light excitation. White light luminescence color could be changed by varying the excitation wavelength. Concentration quenching effect was investigated in this paper. Furthermore, the dependence of luminescence properties on glass compositions was studied. Results showed that the luminescence intensity changed with different network modifier oxides, while the white color luminescence was not affected significantly. - Graphical abstract: Tm{sup 3+} and Dy{sup 3+} ions co-doped aluminoborosilicate glasses, which emit white light under UV light excitation, were prepared. The dependence of luminescence properties on glass compositions was studied, and results showed that the white color luminescence was not affected significantly with different network modifier oxides. This adjustability could broaden application areas.

  12. 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.

  13. 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

  14. Inhomogeneous and homogeneous linewidths in Er 3+-doped chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Bigot, L.; Jurdyc, A.-M.; Jacquier, B.; Adam, J.-L.

    2003-10-01

    The erbium 4I 13/2- 4I 15/2 transition around 1.5 ?m is of prim interest for telecommunications and depends on the erbium ions surrounding. In glasses, the broadening of a transition comes from two contributions: inhomogeneous (due to the disorder) and homogeneous (due to the electron phonon interaction) broadening. Resonant Fluorescence Line Narrowing (RFLN) is a useful tool to separate this two parameters. We will show in this paper that the 4I 13/2- 4I 15/2 transition in chalcogenide glass (GeGaSSb) presents a strong homogeneous character and a smaller inhomogeneous contribution compared to aluminosilicate and fluoride glasses. Consequences on gain saturation will also be discussed.

  15. 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.

  16. Spectroscopic properties of bismuth-germanate glasses co-doped with erbium and holmium ions

    NASA Astrophysics Data System (ADS)

    Ragin, Tomasz; Kochanowicz, Marcin; ?mojda, Jacek; Dorosz, Dominik

    2014-05-01

    In the article an analysis of thermal and spectroscopic properties of heavy metal oxide glasses from the Bi2O3-Ga2O3- Na2O-Ge2O3 system doped with rare earth elements were presented. It has been focused on the elaboration of the glass composition in terms of low phonon energy, high transparency in the range of infrared region and high thermal stability (?T=160 °C) required in optical fiber technology. Fabricated glasses co-doped with Er3+/Ho3+ions under 980 nm laser diode excitation exhibit emission at 1.55 ?m (Er3+: 4I 13/2 ? 4I15/2) and 2.0 ?m (Ho3+: 4I7 ? 5I8). The emission at 2.0 ?m results from the Er3+ ? Ho3+energy transfer. Taking into account great thermal stability and good optical properties such as high transparency (up to 80%) or high refractive index (2.23), the fabricated bismuth-germanate glass co-doped with Er3+/Ho3+ is promising material for construction of active optical fibers operating in the range of mid-infrared.

  17. 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.

  18. X-ray absorption (XANES) and photoelectron spectroscopy (XPS) of gamma irradiated Nd doped phosphate glass

    E-print Network

    Rai, V N; Jha, S N; Bhattacharya, D; Shekhar, B N Raja

    2015-01-01

    This paper presents the X-ray absorption near edge structure (XANES) and X-ray photoelectron spectroscopic (XPS) studies of Nd doped phosphate glasses before and after gamma irradiation. The intensity and location of LIII edge white line peak of Nd are found to be dependent on the concentration of Nd as well as on the ratio of O/Nd in the glass matrix. The decrease in the peak intensity of white line of XANES spectra and asymmetry in the profile of Nd 3d5/2 peak of XPS after gamma irradiation clearly indicates that Nd3+ gets reduced to Nd2+ in the glass matrix, which increases with an increase in the doses of irradiation. Sharpening of Nd 3d5/2 XPS profile indicates about the deficiency of oxygen in the glass after gamma irradiation, which is supported by EDX measurement.

  19. Erbium doped tellurite glasses with improved thermal properties as promising candidates for laser action and amplification

    NASA Astrophysics Data System (ADS)

    Benmadani, Y.; Kermaoui, A.; Chalal, M.; Khemici, W.; Kellou, A.; Pellé, F.

    2013-10-01

    The influence of composition on the thermal stability of tellurite glasses was investigated by using differential scanning calorimetry (DSC). The studied glasses were synthesized by conventional melting quenching method. The best thermal stability and poor crystallization tendency were obtained for the glass composed of 65TeO2-15ZnO-10Na2O-5BaO-3La2O3 doped with Er2O3 (2 mol %). This glass will be referred, in this article, as TZNBL: Er3+ glass. The spectroscopic properties of the above glass are investigated based on the Judd-Ofelt and McCumber theories. The calculated intensity parameters (?2,4,6) are compared to those obtained for Er3+ in other glasses. The radiative emission rate has been calculated for the different Er3+emitting levels. The high values of ?4 and ?6 confirm the results of the DSC experiment concerning the rigidity of the studied glass. Absorption, emission and gain cross section of the 4I13/2 ? 4I15/2 (Er3+) transition in the studied glass are reported and the results are compared to those of other glasses. The 4I13/2 ? 4I15/2 (Er3+) absorption and emission cross sections derived by the application of the Mc Cumber's theory corroborate the Judd-Ofelt results. The whole of results demonstrate that the new composition leads to good thermal and mechanical properties as well efficient Er3+ absorption, emission cross sections, which make this glass as a promising candidate for laser action and amplification.

  20. [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

  1. 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

  2. Spectroscopic properties of transparent Er-doped oxyfluoride glass-ceramics with GdF?.

    PubMed

    ?roda, Marcin; Szlósarczyk, Krzysztof; Ró?a?ski, Marek; Sitarz, Maciej; Jele?, Piotr

    2015-01-01

    Optically active glass-ceramics (GC) with the low-phonon phases of fluorides, doped with Er(3+) was studied. Glass based on SiO?-Al?O?-Na?F?-Na?O-GdF?-BaO system was obtained. Dopant were introduced to the glass in an amount of 0.01 mol Er?O? per 1 mol of glass. DTA/DSC study shows multi-stage crystallization. XRD identification of obtained phases did not confirm the presence of pure GdF? phase. Instead of that ceramization process led to formation of NaGdF? and BaGdF?. The structural changes were studied using FT-IR spectroscopic method. The study of luminescence of the samples confirmed that optical properties of the obtained GC depend on crystallizing phases during ceramization. Time resolved spectroscopy of Er-doped glass showed the 3 and 8 times increase of lifetime of emission from (4)S?/? and (4)F?/? states, respectively. It confirms the erbium ions have ability to locate in the low phonon gadolinium-based crystallites. The results give possibility to obtain a new material for optoelectronic application. PMID:25049170

  3. Spectroscopic properties of transparent Er-doped oxyfluoride glass-ceramics with GdF3

    NASA Astrophysics Data System (ADS)

    ?roda, Marcin; Szlósarczyk, Krzysztof; Ró?a?ski, Marek; Sitarz, Maciej; Jele?, Piotr

    2015-01-01

    Optically active glass-ceramics (GC) with the low-phonon phases of fluorides, doped with Er3+ was studied. Glass based on SiO2-Al2O3-Na2F2-Na2O-GdF3-BaO system was obtained. Dopant were introduced to the glass in an amount of 0.01 mol Er2O3 per 1 mol of glass. DTA/DSC study shows multi-stage crystallization. XRD identification of obtained phases did not confirm the presence of pure GdF3 phase. Instead of that ceramization process led to formation of NaGdF4 and BaGdF5. The structural changes were studied using FT-IR spectroscopic method. The study of luminescence of the samples confirmed that optical properties of the obtained GC depend on crystallizing phases during ceramization. Time resolved spectroscopy of Er-doped glass showed the 3 and 8 times increase of lifetime of emission from 4S3/2 and 4F9/2 states, respectively. It confirms the erbium ions have ability to locate in the low phonon gadolinium-based crystallites. The results give possibility to obtain a new material for optoelectronic application.

  4. Influence of the melting atmosphere on Yb3+/Al3+ co-doped silica glass with powder melting technology

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Zhou, Guiyao; Xia, Changming; Han, Ying; Zhao, Xingtao; Zhang, Wei; Wang, Wei

    2014-03-01

    We demonstrated the formation of Yb2+ ions in Yb3+/Al3+ co-doped silica glass using the powder melting technology based on the high-frequency plasma furnace. The Yb3+ ions can be deoxidated into Yb2+ ions under the atmosphere of N2 or Ar. The appearance and optical properties of the Yb3+/Al3+ co-doped silica glass are also changed.

  5. 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

  6. 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

  7. Silver nanoparticles enhanced luminescence properties of Er³? doped tellurite glasses: Effect of heat treatment

    SciTech Connect

    Fares, Hssen; Férid, Mokhtar; Elhouichet, Habib; Gelloz, Bernard

    2014-09-28

    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 ?I13/2 ? ?I15/2 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 ?I13/2 ? ?I15/2 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.

  8. 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.

  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. 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.

  11. 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; Férid, 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.

  12. 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.

  13. 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 Å and Ag has four I nearest neighbours at 2.78 Å, 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.

  14. Fabrication of Rare Earth-Doped Transparent Glass Ceramic Optical Fibers by Modified Chemical Vapor Deposition

    E-print Network

    Blanc, Wilfried; Nguyen, Luan; Bhaktha, S N B; Sebbah, Patrick; Pal, Bishnu P; Dussardier, Bernard

    2011-01-01

    Rare earth (RE) doped silica-based optical fibers with transparent glass ceramic (TGC) core was fabricated through the well-known modified chemical vapor deposition (MCVD) process without going through the commonly used stage of post-ceramming. The main characteristics of the RE-doped oxyde nanoparticles namely, their density and mean diameter in the fibers are dictated by the concentration of alkaline earth element used as phase separating agent. Magnesium and erbium co-doped fibers were fabricated. Optical transmission in term of loss due to scattering as well as some spectroscopic characteristics of the erbium ions was studied. For low Mg content, nano-scale particles could be grown with and relatively low scattering losses were obtained, whereas large Mg-content causes the growth of larger particles resulting in much higher loss. However in the latter case, certain interesting alteration of the spectroscopic properties of the erbium ions were observed. These initial studies should be useful in incorporati...

  15. Laser performance at 1064 nm in Nd3+ doped oxi-tellurite glasses

    NASA Astrophysics Data System (ADS)

    Bell, Maria Jose; Anjos, Virgílio; 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.

  16. 2.7 ?m fluorescence and energy transfer in Er{sup 3+} doped germanosilicate glasses

    SciTech Connect

    Wei, Tao; Jing, Xufeng; Tian, Ying; Chen, Fangze; Wang, Fengchao; Xu, Shiqing

    2014-06-01

    Highlights: • Novel Er{sup 3+} doped germanosilicate glasses were synthesized. • Excellent thermal stability and 2.7 ?m emission properties were obtained. • High A{sub rad} (33.75 s{sup ?1}) and emission cross section (1.90 × 10{sup ?20} cm{sup 2}) were achieved. • A reasonable energy transfer mechanism was put forward. - Abstract: 2.7 ?m fluorescence has been achieved for the first time in Er{sup 3+} doped novel germanosilicate glasses. Thermal stability, spectroscopic properties and energy transfer mechanism have been investigated in detail. Moreover, the spontaneous transition probability (A{sub rad}) and emission cross section of samples were calculated and analyzed. The prepared Er{sup 3+} doped germanosilicate glasses possessing excellent thermal stability, high A{sub rad} (33.75 s{sup ?1}) and emission cross section of 2.7 ?m (1.90 × 10{sup ?20} cm{sup 2}) provide a new material for the realization of mid-infrared fiber lasers.

  17. 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.

  18. Ni2+ 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 Ni2+ doped LiGa5O8 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, LiGa5O8 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 Ni2+-doped glass ceramic fiber is promising for broadband optical amplification. PMID:26561096

  19. 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 phosphate–cation 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

  20. 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.; Férid, 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.

  1. 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.

  2. Enhancement of cells proliferation and control of bioactivity of strontium doped glass

    NASA Astrophysics Data System (ADS)

    Oudadesse, H.; Dietrich, E.; Bui, X. V.; Le Gal, Y.; Pellen, P.; Cathelineau, G.

    2011-08-01

    Bioactivity and chemical reactivity of bioactive glass offer the ability to bond for soft and hard biological tissues. In this work, synthesis was carried out by using melting and rapid quenching. Strontium was introduced as trace element at different contents in the glass matrix, according to its concentration in the bone matrix. This chemical element presents a high interest in the bone metabolism activity. Investigations were conducted on the surface of biomaterials by using in vitro assay after immersion in SBF. Several physico-chemical methods such as SEM, FTIR, NMR, ICP-OES and MTT test were employed to highlight the effects of the Sr. The in vitro experiments showed that after soaking in SBF, the behaviour of pure glass is different compared to glass doped with Sr. NMR analyses showed in the 29Si MAS-NMR that glass matrix undergoes some changes after in vitro assays particularly the emergence of new components attributed to Q 3(OH). The presence of Sr slowed down the bioactivity of glass after immersion in SBF. The non toxic character of compounds was confirmed. Introduction of Sr at 0.1 wt % induce an enhancement of cells at about 14.3%.

  3. Optical and structural properties of WO3-doped silicophosphate glasses for gamma-ray applications

    NASA Astrophysics Data System (ADS)

    Marzouk, M. A.; Hamdy, Y. M.; ElBatal, H. A.

    2014-01-01

    Optical and FTIR spectral measurements were carried out for prepared base undoped sodium silicophosphate glass together with samples of the same composition containing (0.5%, 0.75%, 1% and 1.25%) WO3 in order to characterize the valence states of tungsten ions in such host mixed forming oxides glass. The same combined spectral studies were repeated after subjecting the prepared samples to gamma irradiation with a dose of 8 M rad (8 × 104 Gy). The base undoped glass exhibits a strong UV absorption band which is related to the presence of unavoidable trace iron (Fe3+) ions impurities contaminated within the raw materials used for the preparation of the base glass. WO3-doped glasses exhibit bluish color and reveal distinct optical absorption peaks which are attributed to the presence of both W6+ and W5+ ions. Infrared absorption spectra of the studied glasses reveal distinct broad IR bands which are attributed to the sharing modes of vibrations of both phosphate and silicate networks. The addition of the dopants (0.5-1.25%) WO3 did not cause marked changes in the IR spectral vibrational bands. Gamma irradiation conducts no variations in the number or position of main IR characteristic absorption bands due to the stability of the glassy network containing combined structural building groups together with the presence of tungsten ions. E.S.R. spectra of WO3-samples reveal spin resonance indicating the presence of unpaired tungsten ions and support the optical result.

  4. 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.

  5. 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.

  6. Crystallization and spectroscopic properties in Er3+ doped oxyfluorogermanate glass ceramics containing Na

    NASA Astrophysics Data System (ADS)

    Hu, Yuebo; Qiu, Sawei; Gao, Yuan; Qiu, Jianbei

    2015-07-01

    The Er3+ doped oxyfluorogermanate glasses, with a composition containing Na element, were synthesized by the conventional melting-quenching technique. When Na element was introduced into the composition of oxyfluorogermanate glass, the crystals behavior was investigated in details. Depending on the annealing procedure supplied, thermal annealing of precursor glasses in the system GeO2/BaF2/AlF3/Na2O/NaF/ZnO/GdF3/ErF3 led to the precipitation of different crystal phase nanocrystals. It was confirmed the nanocrystals in GC600 is orthorhombic NaBaAlF6 which led to enhance obviously in the UC luminescence of Er3+. However, the nanocrystals in G585 led to decrease in the UC luminescence, which indicated few Er ions enter into the lattice of this nanocrystal phase. The reason of the decrease in UC emission intensity of GC585 was analyzed.

  7. Structural and optical characterization of Er3+ doped zinc telluroborate glasses for green laser applications

    NASA Astrophysics Data System (ADS)

    Annapoorani, K.; Ravindran, T. R.; Murthy, N. Suriya; Marimuthu, K.

    2015-06-01

    A new series of Erbium doped Zinc telluroborate glasses were prepared by melt quenching technique. The stretching and bending vibrations of the B-O and Te-O bonds in the prepared glass network were explored through Raman spectra. The nature of the metal-ligand bond was determined using optical absorption spectra through Nephelauxetic ratio (?) and Bonding parameter (?) studies. The Judd-Ofelt (JO) parameters (?2, ?4, ?6) and the oscillator strengths were calculated following JO theory. The relatively higher ?2 values reveal the higher asymmetry nature. The green emission corresponding to the 2H11/2+4S3/2?4I15/2 transition was observed at around 550 nm and the luminescence quenching occurs beyond 1.0 wt% of Erbium ion concentration. Radiative properties for the 1.0EZTB glass are found to be higher and its suitability towards green laser applications were discussed and reported.

  8. White light simulation and luminescence studies on Dy3+ doped Zinc borophosphate glasses

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R.; Venkataiah, G.; Marimuthu, K.

    2015-01-01

    The Dy3+ doped Zinc borophosphate glasses with the chemical composition (79-x)B2O3+xP2O5+10Li2O+10ZnO+1Dy2O3 (where x=0, 10, 20, 30 and 50 in wt%) have been prepared by melt quenching technique. The prepared glass samples were characterized through optical absorption, emission and decay measurements. The bonding parameters, optical band gap and Urbach's energy values were calculated from the optical absorption spectra to explore the bonding nature of the Dy-O metal ligand and electronic band structure of the studied glasses. Judd-Ofelt (JO) intensity parameters were calculated from the absorption spectra by using the JO theory and it gives information about symmetry of the ligand environment around the Dy3+ ion site. The Y/B intensity ratio and radiative properties were obtained from the emission spectra and the results were compared with the reported literature. The x, y chromaticity color coordinates of the studied glasses were analyzed using a CIE 1931 color chromaticity diagram and found that the x, y coordinates lie in the white light region. The decay curve measurements of the prepared glasses exhibit non-exponential behavior and are well fitted to Inokuti-Hirayama (IH) model to understand the energy transfer mechanism between Dy3+ ions. The Q, R0 and CDA values of the prepared Dy3+ doped glasses were obtained from the IH model and the results were discussed and compared with the reported literature.

  9. 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

  10. Effect of SiO2 on the thermal stability and spectroscopic properties of Er3+-doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Zheng, Shi-chao; Zhou, Ya-xun

    2014-05-01

    Er3+-doped tellurite glass (TeO2-ZnO-Na2O) prepared using the conventional melt-quenching method is modified by introducing the SiO2, and its effects on the thermal stability of glass host and the 1.53 ?m band spectroscopic properties of Er3+ are investigated by measuring the absorption spectra, 1.53 ?m band fluorescence spectra, Raman spectra and differential scanning calorimeter (DSC) curves. It is found that for Er3+-doped tellurite glass, besides improving its thermal stability, introducing SiO2 is helpful for the further improvement of the fluorescence full width at half maximum (FWHM) and bandwidth quality factor. The results indicate that the prepared Er3+-doped tellurite glass containing an appropriate amount of SiO2 has good prospect as a candidate of gain medium applied for 1.53 ?m broadband amplifier.

  11. Efficient and long-lived Zeeman-sublevel atomic population storage in an erbium-doped glass fiber

    E-print Network

    Saglamyurek, Erhan; Veissier, Lucile; Hedges, Morgan P; Thiel, Charles W; Cone, Rufus L; Tittel, Wolfgang

    2015-01-01

    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. Despite numerous observations of deep and persistent holes in various cryogenically cooled rare-earth ion doped crystals, the demonstration of their existence in rare-earth ion doped amorphous hosts, e.g. glasses, has remained an open challenge since many decades. Here we report the first 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. Our investigation improves the understanding of the fundamental interaction between impurities and vibrational modes in glassy hosts, and reveals a potential technological application of rare-earth ion doped amorphous materials, including at telecommunication wavel...

  12. Efficient and long-lived Zeeman-sublevel atomic population storage in an erbium-doped glass fiber

    E-print Network

    Erhan Saglamyurek; Thomas Lutz; Lucile Veissier; Morgan P. Hedges; Charles W. Thiel; Rufus L. Cone; Wolfgang Tittel

    2015-07-10

    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. Despite numerous observations of deep and persistent holes in various cryogenically cooled rare-earth ion doped crystals, the demonstration of their existence in rare-earth ion doped amorphous hosts, e.g. glasses, has remained an open challenge since many decades. Here we report the first 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. Our investigation improves the understanding of the fundamental interaction between impurities and vibrational modes in glassy hosts, and reveals a potential technological application of rare-earth ion doped amorphous materials, including at telecommunication wavelength.

  13. 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.

  14. 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

  15. Intense 1.6 ?m fluorescence of Nd{sup 3+} doped cadmium bismuth silicate glasses

    SciTech Connect

    Pal, I. Agarwal, A. Sanghi, S.; Bhardwaj, S.; Sanjay

    2014-04-24

    In this work, Judd-Ofelt analysis is applied to rare-earth (RE = Nd{sup 3+}) doped cadmium bismuth silicate (20CdO?xSiO{sub 2}?(79.5?x)Bi{sub 2}O{sub 3}?0.5Nd{sub 2}O{sub 3} (CSBN)) glasses in order to evaluate their potential as well as both glass laser systems and optical materials. The phenomenological Judd-Ofelt parameters (?{sub 2}, ?{sub 4}, ?{sub 6}) are determined for RE ions with their quality factors and compared with the equivalent parameters for several other hosts. The calculated value of stimulated emission cross-section for {sup 4}F{sub 3/2}?{sup 4}I{sub 11/2} has high and varies 14.72×10{sup ?20} to 9.66×10{sup ?20} cm{sup 2} with Bi{sub 2}O{sub 3} content in the host glass. The results point out that the glass system is good candidate for the development of photonics devices which are operating near infrared spectral range. Further, the FTIR results reveal that the glasses have BiO{sub 6}, SiO{sub 4} and non-bridging oxygen as local structure.

  16. 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

  17. 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.

  18. Luminescence properties of Dy3+ doped different fluoro-phosphate glasses for solid state lighting applications

    NASA Astrophysics Data System (ADS)

    Babu, S.; Reddy Prasad, V.; Rajesh, D.; Ratnakaram, Y. C.

    2015-01-01

    Dy3+ doped different fluoro-phosphate glasses are prepared and they are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Raman, optical absorption, and photoluminescence (PL) techniques. The structural characterization is accomplished by XRD, FTIR and Raman spectroscopy. The morphological analysis was performed by SEM. The absorption spectra have been analyzed using Judd-Ofelt theory and the intensity parameters have been evaluated. These parameters are used to calculate radiative properties such as emission probabilities (AR), radiative lifetimes (?R) and integrated absorption cross-sections (?) for different Dy3+ transitions. The PL spectra exhibit bands in the blue, yellow and red regions. Furthermore, the dependence of luminescence properties such as stimulated emission cross-sections (?p) and branching ratios (?) on different metal cations in these glasses is studied. From decay curve analysis, the lifetimes of the excited state 4F9/2 have been measured. The calorimetric property is also studied based on Commission International del'Eclairage (CIE) standards for Dy3+ doped different fluoro-phosphate glasses and discussed.

  19. 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.

  20. 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.

  1. 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; Rüssel, Christian; Körner, Jörg; Klöpfel, 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?µs). 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.

  2. 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

  3. 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.

  4. Performance improvement of transparent germanium-gallium-sulfur glass ceramic by gold doping for third-order optical nonlinearities.

    PubMed

    Chen, Feifei; Dai, Shixun; Lin, Changgui; Yu, Qiushuang; Zhang, Qinyuan

    2013-10-21

    Transparent chalcogenide glass ceramics were prepared by thermally treating gold-doped germanium-gallium-sulfur glass. The gold, as nucleating agents, modified the crystallization process of the glass, resulting in the formation of nanocrystals belonging to a single ?-Ga?S? phase. The crystalline grains increased in number with the treatment duration while their size remained constant, leading to a high infrared transmittance of the glass ceramics. Z-scan measurements revealed the performance improvement of the ?-Ga?S? nanocrystals to third-order optical nonlinearities. PMID:24150328

  5. 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}/?Fe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

  6. Proton-implanted optical planar waveguides in Yb3+-doped silicate glasses

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Xiao; Cheng, Shu; Guo, Hai-Tao; Li, Wei-Nan; Liu, Xiu-Hong; Wei, Wei; Peng, Bo

    2012-10-01

    We report on the characterization of planar waveguides in Yb3+-doped silicate glasses fabricated by double-energy proton implantation at a total dose of 3 × 1016 ions/cm2. The dark mode spectroscopy and near-field mode profile were evaluated by the prism coupling and end-face coupling methods, respectively. The results indicate that a refractive index enhanced region as well as an optical barrier has been created after the beam process. We propose the ion exchange mechanism between the proton and Na+ ions to illustrate the optical barrier and discuss its influence.

  7. 980nm-1550nm vertically integrated duplexer for hybrid erbium-doped waveguide amplifiers on glass

    NASA Astrophysics Data System (ADS)

    Onestas, Lydie; Nappez, Thomas; Ghibaudo, Elise; Vitrant, Guy; Broquin, Jean-Emmanuel

    2009-02-01

    Ion-exchanged devices on glass have been successfully used to realize passive and active integrated optic devices for sensor and telecom applications. Nowadays, research is focused on the reduction of the chip dimensions with an increase of the number of different function integrated. In this paper we present how the use of two stacked optical layers can allow realizing efficient and compact pump duplexer for ion-exchanged hybrid erbium doped waveguide amplifier. Indeed our complete theoretical study of the device shows that excess losses lower than - 0.1 dB and crosstalk lower than -20 dB can be achieved.

  8. Saturation of absorption in noble metal doped nanocomposite glass film excited by evanescent light field

    NASA Astrophysics Data System (ADS)

    Corbari, Costantino; Beresna, Martynas; Kazansky, Peter G.

    2010-12-01

    A leaky-waveguide configuration is proposed for saturable absorbers. Evanescent field interaction between the leaky-mode and the absorber layer reduces material degradation at high power levels while providing control over the interaction length and thus the modulation strength and nonsaturable losses simply by tuning the coupling angle around the resonance of the leaky-mode. This concept was applied to a sol-gel silicon-dioxide glass film doped with gold nanoparticles. Saturation of the surface plasmon resonance absorption was demonstrated with modulation depths of up to 34% achieved.

  9. 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.

  10. Resonant effects in nonlinear photon absorption during femtosecond laser ablation of Nd-doped silicate glass.

    PubMed

    Zhao, Yadong; Jiang, Lan; Fang, Juqiang; Chen, Qianghua; Li, Xiaowei; Lu, Yongfeng

    2012-10-10

    This study investigates the resonant effects in nonlinear photon absorption in femtosecond laser ablation of Nd-doped silicate glass (Nd:glass). During the femtosecond laser ablation process, the resonant ablation threshold fluence is decreased by up to 40% compared with that of ordinary ablation. However, it is found that the resonant effect is closely related with laser intensity, and lower laser intensities are required to achieve a significant enhancement. When the intensity is lower than 2.28×10(14) W/cm(2) at which multiphoton ionization dominates, resonant effect is enhanced by a factor of 1.4 to 4.4. When the intensity is higher than 2.28×10(14) W/cm(2), at which intensity tunnel ionization dominates, the resonant effect becomes weak and gradually fades away. It is shown that the resonant effect is still important for multiphoton ionization yet insignificant for tunnel ionization. PMID:23052083

  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. 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 (0.95×10(-20)??cm(2)) demonstrate that oxyfluorotellurite glass contained with 50 mol.% TeO2 has potential application in the mid-infrared region laser. PMID:25967322

  13. Luminescence properties of Nd3+ and Er3+ doped glasses in the VUV region

    NASA Astrophysics Data System (ADS)

    Yamanoi, Kohei; Murata, Takahiro; Arikawa, Yasunobu; Nakazato, Tomoharu; Cadatal-Raduban, Marilou; Shimizu, Toshihiko; Sarukura, Nobuhiko; Nakai, Mitsuo; Norimatsu, Takayoshi; Nishimura, Hiroaki; Azechi, Hiroshi; Fujino, Shigeru; Yoshida, Hideki; Yoshikawa, Akira; Satoh, Nakahiro; Kan, Hirofumi

    2013-09-01

    We report the vacuum ultraviolet (VUV) spectroscopy of APLF + Nd and APLF + Er glass, with composition 20Al(PO3)3-80LiF + 1NdF3 and + 1ErF3 (in mol%). APLF + Nd and APLF + Er have a dominant fluorescence peak at 185 nm and 168 nm with decay times of 4.5 ns and 5.8 ns, respectively. Fluorescence from APLF + Nd is attributed to 4f25d ? 4f3 transitions in neodymium (Nd) while fluorescence from APLF + Er is due to spin allowed transition in erbium (Er). This is the first report of VUV fluorescence from rare earth ions doped in glass hosts, which could provide the basis for mass production of VUV emitting materials. Our results also suggest the potential of using APLF + Nd and APLF + Er as neutron scintillators during inertial confinement fusion.

  14. 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.

    2015-03-01

    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.

  15. Effect of AgCl on spectroscopic properties of erbium doped zinc tellurite glass

    NASA Astrophysics Data System (ADS)

    Reza Dousti, M.; Sahar, M. R.; Ghoshal, S. K.; Amjad, Raja J.; Samavati, A. R.

    2013-03-01

    The Er3+ doped zinc tellurite glass containing Ag nanoparticles (NPs) were synthesized from high purity raw materials by melt quenching method and the influence of Ag NPs on the spectroscopic properties were investigated. The glasses are characterized using DTA, EDX, TEM, FTIR, UV-Vis-NIR and photoluminescence (PL) techniques. The DTA data reveal that the addition of silver chloride increased the thermal stability from 0.52 to 0.67 for samples without and with 2 mol% AgCl respectively. The sharp peaks in EDX spectra show the presence of Ag nanocrystallites. The TEM micrograph shows the distribution of NPs is Gaussian and the average size is estimated ˜10 nm. Seven absorption bands of erbium were evidenced in the UV-Vis-NIR measurements. Optical band gap and density were found to decrease with addition of AgCl concentration, while molar volume increased. The PL spectra exhibit four peaks corresponding to 2H11/2 ? 4I15/2, 4S3/2 ? 4I15/2, 4F9/2 ? 4I15/2 and 4S3/2 ? 4I13/2 transitions. An enhancement in the order of six times for 2 mol% of dopant and a subsequent quench in luminescence spectra of co-doped zinc tellurite glasses were observed. Such enhancements were attributed to silver nanoparticles with average size of 10 nm and absorption band centered at 552 nm. The studied glasses provide enormous scope to achieve the materials suitable for nanophotonics, solid state lasers and color displays.

  16. 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.

  17. Formation of nanostructures in Eu3+ doped glass-ceramics: an XAS study.

    PubMed

    Pellicer-Porres, J; Segura, A; Martínez-Criado, G; Rodríguez-Mendoza, U R; Lavín, V

    2013-01-16

    We describe the results of x-ray absorption experiments carried out to deduce structural and chemical information in Eu(3+) doped, transparent, oxyfluoride glass and nanostructured glass-ceramic samples. The spectra were measured at the Pb and Eu-L(III) edges. The Eu environment in the glass samples is observed to be similar to that of EuF(3). Complementary x-ray diffraction experiments show that thermal annealing creates ?-PbF(2) type nanocrystals. X-ray absorption indicates that Eu ions act as seeds in the nanocrystal formation. There is evidence of interstitial fluorine atoms around Eu ions as well as Eu dimers. X-ray absorption at the Pb-L(III) edge shows that after the thermal treatment most lead atoms form a PbO amorphous phase and that only 10% of the lead atoms remain available to form ?-PbF(2) type nanocrystals. Both x-ray diffraction and absorption point to a high Eu content in the nanocrystals. Our study suggests new approaches to the oxyfluoride glass-ceramic synthesis in order to further improve their properties. PMID:23197076

  18. 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.

  19. Spectroscopic properties of Er3+, Yb3 + and Er3 + /Yb3+ doped metaphosphate glasses.

    PubMed

    Speghini, A; Francini, R; Martinez, A; Tavernese, M; Bettinell, M

    2001-09-01

    The absorption and emission spectroscopies of Er3+ doped and Er3+/Yb3+ codoped Ca(PO3)2, Sr(PO3)2 and Ba(PO3)2 glasses have been studied. From the Judd-Ofelt intensity parameters, the spontaneous emission probabilities of some relevant transitions and the radiative lifetimes of several excited states of Er3+ have been calculated. The decay curves of the Er3+ emission at 1.5 microm have been measured at different temperatures. The data have been fitted using a stretched exponential function and the obtained experimental lifetimes have been compared with the calculated radiative lifetimes. The difference between the experimental and calculated lifetimes is attributed to the presence of traces of OH groups in the host glasses. The absolute OH content in some glasses has been determined from the infrared spectra. The emission spectra at 1.5 microm of the Er3+ ion in the codoped glasses have been measured at different temperatures. The integrated emission intensities decrease significantly on passing from room temperature to 13 K, suggesting a temperature dependence of the rate of the energy transfer process between Yb3+ and Er3+. PMID:11666080

  20. Antibacterial and bioactive composite bone cements containing surface silver-doped glass particles.

    PubMed

    Miola, Marta; Fucale, Giacomo; Maina, Giovanni; Verné, 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

  1. VOLUME 85, NUMBER 17 P H Y S I C A L R E V I E W L E T T E R S 23 OCTOBER 2000 Observation of Anti-Stokes Fluorescence Cooling in Thulium-Doped Glass

    E-print Network

    Sheik-Bahae, Mansoor

    -Stokes Fluorescence Cooling in Thulium-Doped Glass C. W. Hoyt* and M. Sheik-Bahae Optical Sciences and Engineering (Received 28 June 2000) We report the first observation of anti-Stokes fluorescence cooling in a thulium demonstration of laser induced cooling of a thulium-doped glass--the second solid after Yb31 -doped glass

  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, Frédéric; Doualan, Jean-Louis; Moncorgé, 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 Fütchbauer-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 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.

  4. 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 2.61±0.03ms and almost invariant for Tb3+ concentrations less than 15wt% (1.68×1021ions/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 8.1×10-22cm2 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.

  5. 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.

  6. Optical and spectroscopic characterization of Er3+-Yb3+co-doped tellurite glasses and fibers

    NASA Astrophysics Data System (ADS)

    Narro-García, 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 µm.

  7. Optical and spectroscopic properties of soda-lime alumino silicate glasses doped with Er 3+ and/or Yb 3+

    NASA Astrophysics Data System (ADS)

    Berneschi, S.; Bettinelli, M.; Brenci, M.; Dall'Igna, R.; Nunzi Conti, G.; Pelli, S.; Profilo, B.; Sebastiani, S.; Speghini, A.; Righini, G. C.

    2006-08-01

    A new set of soda-lime alumino silicate (SLAS) glasses doped with a fixed percentage of Er 3+ and different percentages of Yb 3+ ions was produced by conventional melting process. Their spectroscopic properties, namely absorption and emission spectra, radiative and experimental lifetimes, were measured and are discussed here. Planar and channel optical waveguides were produced in these glasses by ion-exchange, and their characterization is reported as well.

  8. 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.

  9. Ni{sup 2+}-doped new silicate glass-ceramics for superbroadband optical amplification

    SciTech Connect

    Xu Shiqing; Deng Degang; Bao Renqiang; Ju Haidong; Zhao Shilong; Wang Huanping; Wang Baolin

    2008-09-15

    Transparent Ni{sup 2+}-doped new La{sub 2}O{sub 3}-Ga{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-SiO{sub 2} (LGAS) glass-ceramics (GC) embedding {beta}-Ga{sub 2}O{sub 3} nanocrystals was prepared. Upon excitation at 970 nm, an emission band at around 1200 nm was observed originating from the {sup 3}T{sub 2}({sup 3}F){yields}{sup 3}A{sub 2}({sup 3}F) transition of Ni{sup 2+} in distorted octahedral sites. Effects of both heat-treated temperature and doping content on the luminescent properties were also studied. The results revealed that a concentration quenching of the luminescence occurs as the molar ratio of Ni{sup 2+} exceeds the optimum value. The superbroadband near-infrared (NIR) emission from Ni{sup 2+}-doped new GC can be as host materials for a broadband optical amplifier.

  10. 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

  11. The Effect of Remelting on the Physical Properties of Borotellurite Glass Doped with Manganese

    PubMed Central

    Hashim, Syed Putra Hashim Syed; Sidek, Haji Abdul Aziz; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Yusof, Wan Mohamad Daud Wan; Zaid, Mohd Hafiz Mohd

    2013-01-01

    A systematic set of borotellurite glasses doped with manganese (1–x) [(B2O3)0.3(TeO2)0.7]-xMnO, with x = 0.1, 0.2, 0.3 and 0.4 mol%, were successfully synthesized by using a conventional melt and quench-casting technique. In this study, the remelting effect of the glass samples on their microstructure was investigated through density measurement and FT-IR spectra and evaluated by XRD techniques. Initial experimental results from XRD evaluation show that there are two distinct phases of glassy and crystallite microstructure due to the existence of peaks in the sample. The different physical behaviors of the studied glasses were closely related to the concentration of manganese in each phase. FTIR spectra revealed that the addition of manganese oxide contributes the transformation of TeO4 trigonal bipyramids with bridging oxygen (BO) to TeO3 trigonal pyramids with non-bridging oxygen (NBO). PMID:23296276

  12. Effect of crystallization heat treatment on the microstructure of niobium-doped fluorapatite glass-ceramics

    PubMed Central

    Denry, I.; Holloway, J.A.; Gupta, P.K.

    2012-01-01

    Our goal was to study the effect of heat treatment temperature and heating rate on the microstructure and crystalline phases and assess the domain of existence of sub-micrometer fluorapatite crystals in niobium-doped fluorapatite glass-ceramics for biomedical applications. Glass-ceramic specimens were prepared by casting and heat treatment between 700 and 1200°C using a fast or a slow heating rate. The microstructure was characterized by atomic force microscopy and scanning electron microscopy. Crystalline phases were analyzed by x-ray diffraction. AFM of the as-cast glass revealed that amorphous phase separation occurred in this system. XRD confirmed the presence of fluorapatite in all specimens, together with forsterite and enstatite at higher temperatures. Both heating rate and heat treatment temperature strongly influenced microstructure and crystallinity. A dual microstructure with sub-micrometer fluorapatite crystals and polygonal forsterite crystals was obtained when slow heating rates and crystallization temperatures between 950 and 1100°C were used. Needle-shaped fluorapatite crystals appeared after heat treatment above 1100°C. Fast heating rates led to an increase in crystal size. Heat treatment temperatures should remain below 1100°C, together with slow heating rates, to prevent crystal dissolution, and preserve a dual microstructure of finely dispersed sub-micrometer crystals without growth of needle-shaped crystals. PMID:22454333

  13. 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.

  14. Effect of crystallization heat treatment on the microstructure of niobium-doped fluorapatite glass-ceramics.

    PubMed

    Denry, I; Holloway, J A; Gupta, P K

    2012-07-01

    Our goal was to study the effect of heat treatment temperature and heating rate on the microstructure and crystalline phases and assess the domain of existence of submicrometer fluorapatite crystals in niobium-doped fluorapatite glass-ceramics for biomedical applications. Glass-ceramic specimens were prepared by casting and heat treatment between 700 and 1200°C using a fast or a slow heating rate. The microstructure was characterized by atomic force microscopy and scanning electron microscopy. Crystalline phases were analyzed by x-ray diffraction. AFM of the as-cast glass revealed that amorphous phase separation occurred in this system. XRD confirmed the presence of fluorapatite in all specimens, together with forsterite and enstatite at higher temperatures. Both heating rate and heat treatment temperature strongly influenced microstructure and crystallinity. A dual microstructure with submicrometer fluorapatite crystals and polygonal forsterite crystals was obtained when slow heating rates and crystallization temperatures between 950 and 1100°C were used. Needle-shaped fluorapatite crystals appeared after heat treatment above 1100°C. Fast heating rates led to an increase in crystal size. Heat treatment temperatures should remain below 1100°C, together with slow heating rates, to prevent crystal dissolution, and preserve a dual microstructure of finely dispersed submicrometer crystals without growth of needle-shaped crystals. PMID:22454333

  15. Application of Cu2O-doped phosphate glasses for bandpass filter

    NASA Astrophysics Data System (ADS)

    Elhaes, H.; Attallah, M.; Elbashar, Y.; El-Okr, M.; Ibrahim, M.

    2014-09-01

    Phosphate glasses doped with copper ions having general composition 42P2O5-39ZnO-(18-x) Na2O-1CaO-xCu2O [x=2, 4, 6, 8, 10 mol%] were prepared using a conventional melt-quench technique. Physical and chemical properties of the glasses were investigated using X-ray diffraction technique and UV-visible optical absorption. The density was measured by Archimedes' method, and molar volume (VM) was calculated. It is found that density and molar volume show opposite trend by increasing Cu2O content. Absorbance and transmittance at the normal incidence are measured by a spectrophotometer in the spectral range of 190-1100 nm. Analyses of the obtained results were considered in the frame of current theories. Absorption data were used for absorption coefficient, the optical band gap (Eopt), the cutoff in UV and IR bands to the bandpass filter, which confirmed the optical properties of this type of filter. Eopt values for different glass samples are found to decrease with increasing Cu2O content.

  16. Broadband near infrared emission in antimony-germanate glass co-doped with erbium and thulium ions

    NASA Astrophysics Data System (ADS)

    Dorosz, Dominik; Zmojda, Jacek; Kochanowicz, Marcin

    2014-07-01

    Antimony-germanate glasses co-doped with Er/Tm ions as a material for active waveguides application have been investigated. In result of optimizations of rare earths, concentration wide (??FWHM=420 nm) luminescence emission in the range of 1.4 to 1.9 ?m was obtained for molar composition of 1%Er2O3: 0.25%TmO. The influence of the molar ratio of active ions on the luminescence spectra has been investigated. Luminescent properties of fabricated glass indicate that elaborated glass is promising material for broad tunable integrated laser sources and broadband optical amplifiers.

  17. Structural, thermal, and optical properties of Er3+/Yb3+ co-doped oxyhalide tellurite glasses, glass-ceramics and ceramics

    NASA Astrophysics Data System (ADS)

    Joshi, C.; Rai, R. N.; Rai, S. B.

    2012-04-01

    Glass-ceramics and ceramics containing nano-crystals of different phases doped with Er3+/Yb3+ ions have been successfully prepared by heat treatment of the precursor oxyhalide glasses synthesized by the melt-quench method. X-ray diffraction patterns and transmission electron microscopy (TEM) images verify the precipitation of nano-crystals. Emission of Er3+ enhances several times when Yb3+ ion is added with the matrix. The Stark splitting and the intensity of different emission bands increase to a great extent when we approach to ceramics from glasses via glass-ceramics. The intensity of the blue and green emission bands increases much faster than the red and NIR emission bands. Intense upconversion emission observed by the naked eye has been quantified in terms of standard chromaticity diagram (CIE). Power dependence study shows that the upconversion of NIR radiation to visible radiation takes place mainly via photon avalanche (PA) process.

  18. Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: synthesis, microstructure and biological responsiveness.

    PubMed

    Bellucci, Devis; Sola, Antonella; Cacciotti, Ilaria; Bartoli, Cristina; Gazzarri, Matteo; Bianco, Alessandra; Chiellini, Federica; Cannillo, Valeria

    2014-09-01

    Presently, there is an increasing interest towards the composites of calcium phosphates, especially ?-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG_Ca/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850°C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG_Ca/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg(2+) and Sr(2+) ions. PMID:25063124

  19. Luminescence and microstructure of Sm{sup 2+} ions reduced by x-ray irradiation in Li{sub 2}O-SrO-B{sub 2}O{sub 3} glass

    SciTech Connect

    Huang Yanlin; Jiang, Chuanfang; Jang, Kiwan; Lee, Ho Sueb; Cho, Eunjin; Jayasimhadri, M.; Yi, Soung-Soo

    2008-06-01

    Sm{sup 3+}-doped Li{sub 2}O-SrO-B{sub 2}O{sub 3} glass sample was prepared by the conventional melt quenching method in air atmosphere. Sm{sup 2+} ions in this borate glass were obtained by x-ray irradiation reduction method. The as-prepared and x-ray-irradiated samples were investigated by photoluminescence spectrum and decay curve measurements. The dependence of Sm{sup 2+} luminescence intensity on the x-ray irradiation time was investigated. It is found that the conversion of Sm{sup 3+}{yields}Sm{sup 2+} after x-ray irradiation is efficient in this borate glass. Photostability of Sm{sup 2+} ions was evaluated by the photobleaching method. Furthermore, the induced optical absorption spectrum measurement after x-ray irradiation was performed. Thermoluminescence above room temperature was also studied after x-ray irradiation. The different kinds of defect structures and the reduction mechanism of Sm{sup 2+} ions in this borate glass were discussed. The microstructure of Sm ions in the Li{sub 2}O-SrO-B{sub 2}O{sub 3} glass was suggested. The proposed microstructure would be helpful to understand the reduction mechanism of Sm{sup 2+} ion in borate glasses.

  20. Magnetic properties and homogeneous distribution of Gd{sup 3+} ions in gadolinium molybdenum borate glass with high Gd{sub 2}O{sub 3} content

    SciTech Connect

    Suzuki, F.; Honma, T.; Doi, Y.; Hinatsu, Y.; Komatsu, T.

    2012-11-15

    Highlights: ? The magnetic susceptibility of Gd{sub 2}O{sub 3}–MoO{sub 3}–B{sub 2}O{sub 3} glass was examined in T = 1.8–300 K. ? The effective magnetic moment was ?{sub eff} = 7.87 ?{sub B}. ? The Weiss constant was ? = ?0.7 K. ? Gd{sup 3+} ions are distributed homogeneously as paramagnetic ions down to T = 1.8 K. -- Abstract: The magnetic susceptibility and specific heat of 21.25Gd{sub 2}O{sub 3}–63.75MoO{sub 3}–15B{sub 2}O{sub 3} (mol%) glass showing the crystallization of ferroelastic ??-Gd{sub 2}(MoO{sub 4}){sub 3} crystals are examined in the temperature range of T = 1.8–300 K to clarify magnetic and distribution states of Gd{sup 3+} ions. The magnetic susceptibility obeys the Curie–Weiss law, giving the effective magnetic moment of ?{sub eff} = 7.87 ?{sub B} and the Weiss constant of ? = ?0.7 K. Any peak such as ?-type anomaly is not observed in the temperature dependence of specific heat in T = 1.8–5 K. It is suggested that Gd{sup 3+} ions in the glass with a high Gd{sub 2}O{sub 3} content of 21.25 mol% are distributed homogeneously and randomly as paramagnetic ions down to T = 1.8 K without inducing any strong magnetic interaction. The present study suggests that glasses based on the MoO{sub 3}–B{sub 2}O{sub 3} system are good hosts for the homogeneous solubility of a large amount of rare-earth oxides.

  1. Effects of F- on the optical and spectroscopic properties of Yb3+/Al3+-co-doped silica glass

    NASA Astrophysics Data System (ADS)

    Xu, Wenbin; Yu, Chunlei; Wang, Shikai; Lou, Fengguang; Feng, Suya; Wang, Meng; Zhou, Qinling; Chen, Danping; Hu, Lili; Guzik, Malgorzata; Boulon, Georges

    2015-04-01

    Yb3+/Al3+-co-doped silica glasses with different F- content were prepared in this work by sol-gel method combined with high temperature sintering. XRF, FTIR and XPS methods were used to confirm the presence of F-. The effects of F- on the optical and spectroscopic properties of these glasses have been investigated. It is worth to notice that the F-/Si4+ mass ratio equal to 9% is a significant value showing a real change in the variation trends of numerous following parameters: refractive index, UV absorption edge, absorption and emission cross sections, scalar crystal-field NJ and fluorescent lifetimes. Furthermore, introduction of F- can adjust the refractive index of Yb3+/Al3+-co-doped silica glass and it is useful for large mode area (LMA) fibers.

  2. Effect of Ce2O3 on the 1.53 ?m spectroscopic properties in Er3+-doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Zheng, Shi-chao; Zhou, Ya-xun; Xue, Rui

    2015-03-01

    Er3+/Ce3+ co-doped tellurite-based glasses with composition of TeO2-ZnO-Na2O are prepared by high- temperature melt-quenching technique. Effects of Ce2O3 content on the 1.53 ?m band fluorescence spectra and fluorescence lifetime of Er3+ are measured and investigated. It is found that the tellurite glass containing Ce2O3 with molar concentration of 0.25% exhibits an increment of 13% in 1.53 ?m fluorescence intensity and an increment of 15% in the 4I13/2 level lifetime. The results indicate that the prepared tellurite-based glass with a suitable Er3+/Ce3+ codoping concentration is an excellent gain medium applied for broadband Er3+-doped fiber amplifier (EDFA) pumped with a 980 nm laser diode.

  3. Study of spatial rings in TPPOH4 doped in boric acid glass

    NASA Astrophysics Data System (ADS)

    Rao Allam, Srinivasa; Dar, Mudasir H.; Venkatramaiah, N.; Venkatesan, R.; Sharan, Alok

    2015-02-01

    Single beam optical nonlinearity is studied in TPPOH4 doped in boric acid sandwiched films between two microscope glass slides at three different molar concentrations (4×10-4M, 1×10-4M, 5×10-5M). It shows absorption peak at 700nm with bandwidth of 70nm. We have used diode laser output at 671nm to probe resonant optical nonlinearities. We have observed interesting phenomena of formation of spatial concentric rings centered on the z-axis of the sample. To our knowledge this is first such observation of spatial rings in these systems. We have carried out studies to separate the contribution to the ring formation due to absorptive/refractive optical nonlinearity and the thermal nonlinearity.

  4. Fabrication and annealing optimization of oxygen-implanted Yb3+-doped phosphate glass planar waveguides

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Xiao; Xu, Jun; Li, Wei-Nan; Xu, Xiao-Li; Guo, Hai-Tao; Wei, Wei; Wu, Gen-Gen; Hu, Yue; Peng, Bo

    2014-11-01

    Optical planar waveguides in Yb3+-doped phosphate glasses are fabricated by (5.0+6.0) MeV O3+ ion implantation at fluences of (4.0+8.0)×1014 ions/cm2. The annealing treatment is carried out to optimize waveguide performances. The prism-coupling and end-face coupling methods are used to measure the dark-mode spectra and near-field intensity distributions before and after annealing at 350 °C for 60 min, respectively. The refractive index profile of the planar waveguide is obtained based on the reflectivity calculation method. The micro-Raman spectrum of the waveguide is in agreement with that of the bulk, exhibiting possible applications for integrated active photonic devices.

  5. Optical properties of phosphate glasses co-doped with Yb3+ and silver nanoparticles

    NASA Astrophysics Data System (ADS)

    A. Vallejo H., M.; A. Martinez G., M.; V. Kiryanov, A.; L. Lucio M., J.

    2014-12-01

    We report the fabrication and spectroscopic characterization of Yb3+-doped phosphate glass, also containing silver nitrate. Scanning electron microscopy (SEM) provides the evidence of the formation of silver nano-particles (SNPs), which are formed as a consequence of melting and thermal decomposition of AgNO3. Absorption spectra of the samples in the visible-to-near-infrared spectral range reveal the presence of bands centered at 410 nm associated with the SNP-plasmon resonance, and at 976 nm due to the Yb3+. Under 916-nm laser-diode pumping, the effect of the SNP reflects that: i) the fluorescence in the 950-nm-1150-nm spectral range is strongly enhanced(~ 30 times), while the fluorescence decay time associated with the 2F5/2 ? 2F7/2 transition of Yb3+ increases 25%, and ii) the basic lasing properties (saturation pumping intensity, the emission and absorption cross sections) are substantially improved.

  6. Anti-Stokes photoluminescence in Ga/Bi co-doped sol-gel silica glass.

    PubMed

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

    2015-04-01

    Unusual temperature dependence of the anti-Stokes photoluminescence (ASPL) at 734 nm was found in Ga/Bi co-doped sol-gel silica glass. While in the temperature range of 450-873 K, the behavior of ASPL is completely determined by the thermal population of the excited state levels, its intensity is continuously increasing with decreasing temperature in the range of 77-430 K. By measuring the pump power dependence of ASPL at 300 K, we show that the latter can be described via the two-step intracenter excitation process and subsequent relaxation. Based on the measurements of temperature dependence of the excitation spectra of near infrared band (at 1140 nm) and that corresponding to the ASPL (at 734 nm), we propose a simple rate equation model to explain the unusual behavior of ASPL. PMID:25831392

  7. Localized surface plasmon resonance interaction with Er3+-doped tellurite glass.

    PubMed

    Rivera, V A G; Osorio, S P A; Ledemi, Y; Manzani, D; Messaddeq, Y; Nunes, L A O; Marega, E

    2010-11-22

    We show the annealing effect on silver and Erbium-doped tellurite glasses in the formation of nanoparticles (NPs) of silver, produced by the reduction of silver (Ag+ ? Ag0), aiming to an fluorescence enhancement. The absorption spectra show typical Localized Surface Plasmon Resonance (LSPR) band of Ag0 NP in addition to the distinctive absorption peaks of Er3+ ions. Both observations demonstrate that the photoluminescence enhancement is due to the coupling of dipoles formed by NPs with the Er3+ 4I(13/2) ? 4I(15/2) transition. This plasmon energy transfer to the Er3+ ions was observed in the fluorescence spectrum with a blue-shift of the peaks. PMID:21164880

  8. Temperature dependence of the absorption spectra in CdTe-doped glasses

    NASA Astrophysics Data System (ADS)

    Redígolo, M. L.; Arellano, W. A.; Barbosa, L. C.; Brito Cruz, C. H.; Cesar, C. L.; de Paula, A. M.

    1999-01-01

    We present absorption spectra as a function of temperature for CdTe quantum dots in doped glasses. We calculate the absorption spectra considering the transition energies from a spherical 0268-1242/14/1/007/img9 model. We consider also the inhomogeneous broadening due to the quantum-dot size distribution and the homogeneous broadening, due mainly to electron-phonon interactions. The samples grown with a two-step heat treatment present very thin size distributions, with a standard deviation of 5.8%, which is comparable to the best CdSe samples in the literature. Also, the results show that the homogeneous width increases as the quantum-dot size decreases, indicating an enhancement of the electron-phonon interaction for small dots.

  9. LEACHABILITY OF BORATE-MODIFIED OSB

    E-print Network

    ;Borate ChemicalsBorate Chemicals · Water Soluble Type Sodium Borate Boric Oxide (B2O3) Boric Acid (H3BO3: A standardized leaching test method for treated wood composites!! #12;Panel Boric Acid Equivalent Analysis #12

  10. Correlation of EMR and optical spectroscopy data for Cr3+ and Mn2+ ions doped into yttrium aluminum borate YAl3(BO3)4 crystal - Extracting low symmetry aspects

    NASA Astrophysics Data System (ADS)

    Rudowicz, Czes?aw; Gnutek, Pawe?; Aç?kgöz, Muhammed

    2015-08-01

    In this study, the crystal field analysis for Cr3+ and Mn2+ ions doped into yttrium aluminum borate YAl3(BO3)4, for short YAB, crystal has been carried out to complement earlier study of the zero-field splitting (ZFS) parameters (ZFSPs). This analysis utilizes data on the distortion models obtained from analysis of the ZFSPs obtained experimentally by EMR for Cr3+ and Mn2+ ions at the Y3+ and Al3+ sites in YAB. This approach enables to verify and enhance reliability of the ZFSP modeling based on superposition model (SPM) analysis and the distortion models predicted previously. Subsequently, modeling of the crystal field parameters (CFPs) based on SPM analysis is carried out for Cr3+ and Mn2+ ions located at possible cation sites in YAB. The SPM predicted CFP values serve as input for the Crystal Field Analysis (CFA) package to calculate the CF energy levels. The predicted physical ZFS of the ground spin state, i.e. the 4A2 state for Cr3+ ion and the 6S state Mn2+ ions, enable calculation of the theoretical ZFSP values, D and D & (a-F), respectively, using the microscopic spin Hamiltonian (MSH) module in the CFA package. In this way, data on the distortions around the Cr3+ centers in YAB (and to a certain extent also for Mn2+ centers) obtained using the ZFSP data from EMR measurements may be correlated with data on the CF energy levels measured by optical spectroscopy. This modeling approach uncovers certain incompatibilities in the existing data for Cr3+:YAB, which call for reanalysis of the previous assignments of the energy levels observed in optical spectra and more accurate experimental data.

  11. Thin transparent W-doped indium-zinc oxide (WIZO) layer on glass.

    PubMed

    Lee, Young-Jun; Lim, Byung-Wook; Kim, Joo-Hyung; Kim, Tae-Won; Oh, Byeong-Yun; Heo, Gi-Seok; Kim, Kwang-Young

    2012-07-01

    Annealing effect on structural and electrical properties of W-doped IZO (WIZO) films for thin film transistors (TFT) was studied under different process conditions. Thin WIZO films were deposited on glass substrates by RF magnetron co-sputtering technique using indium zinc oxide (10 wt.% ZnO-doped In2O3) and WO3 targets in room temperature. The post annealing temperature was executed from 200 degrees C to 500 degrees C under various O2/Ar ratios. We could not find any big difference from the surface observation of as grown films while it was found that the carrier density and sheet resistance of WIZO films were controlled by O2/Ar ratio and post annealing temperature. Furthermore, the crystallinity of WIZO film was changed as annealing temperature increased, resulting in amorphous structure at the annealing temperature of 200 degrees C, while clear In2O3 peak was observed for the annealed over 300 degrees C. The transmittance of as-grown films over 89% in visible range was obtained. As an active channel layer for TFT, it was found that the variation of resistivity, carrier density and mobility concentration of WIZO film decreased by annealing process. PMID:22966618

  12. P2O5-doping in waste glasses: evolution of viscosity and crystallization processes

    NASA Astrophysics Data System (ADS)

    Tarrago, Mariona; Espuñes, Alex; Garcia-Valles, Maite; Martinez, Salvador

    2015-04-01

    Current concern for environmental preservation is the main motive for the study of new, more sustainable materials. Increasing amounts of sewage sludge are produced in wastewater treatment plants over the world every day. This fact represents a major problem for the municipalities and industries due to the volume of waste and also to the contaminant elements it may bear, which require expensive conditions for disposal in landfills. Vitrification is an established technique in the inertization of different types of toxic wastes (such as nuclear wastes and contaminated soils) that has been used successfully for sewage sludge. Glasses of basaltic composition (43.48SiO2-14.00Al2O3-12.86Fe2O3-10.00CaO-9.94MgO-3.27Na2O-1.96K2O-0.17MnO-0.55P2O5-2.48TiO2) are used as a laboratory analogous of wastes such as sewage sludge and galvanic sludge to study the properties of the inertization matrix. This basaltic matrix is doped by adding 1%, 2%, 3%, 4% and 20% of P5O5 in order to cover the compositional range of phosphate in sewage sludge encountered in the literature. In this study, the focus has been placed in the effect of the concentration of phosphate (P2O5) in glass stability, thermal properties and evolution of viscosity with temperature. The dependence of viscosity on temperature and the thermal behaviour of these glasses are critical parameters in the design of their production process. Regarding the compositional limits of the mixture, it has been observed that melt reactivity is much increased when P2O5 content is over 4%, hindering the glass conformation process. Moreover, stanfieldite (calcium and magnesium phosphate) crystallized during glass making when phosphate concentration approached 20%, hence establishing the upper limit for glass stability. Viscosity is also dramatically increased in this range, hence requiring production amends. Differential thermal analysis has provided nucleation and crystallization temperatures of the glasses around 915°C and 1050°C respectively at phosphate contents up to 4%. Subsequent analysis by X-Ray Diffraction has proved that newly formed phases are iron oxides, Ca - Mg silicates and feldspars. Glass transition temperature (Tg; approximately 635°C) obtained by dilatometry remains almost constant until very high phosphate contents; even then, the increase is not large (650°C at 20% P2O5). Hot-Stage microscopy (HSM) has shown the evolution of viscosity with temperature through the analysis of the morphological evolution of cylindrical probes of glass according to German standard DIN 51730. The annealing range (viscosity between 1013.5 and 1012 is reached at temperatures between 600 and 700°C. The temperatures of the lower limit of the working range (viscosity under 103 Pa-s) are between 1325 and 1375°C; decreasing slightly with the addition of P2O5.

  13. Structural, thermal, optical properties and simulation of white light of titanium-tungstate-tellurite glasses doped with dysprosium

    SciTech Connect

    Jyothi, L.; Upender, G.; Kuladeep, R.; Rao, D. Narayana

    2014-02-01

    Graphical abstract: CIE coordinate diagram of different concentrations of the Dy{sup 3+}-doped TTWD glasses with coordinates in the white light region. - Highlights: • Radiative lifetime of {sup 4}F{sub 9/2} level of Dy{sup 3+} ions is longer in the tellurite glass. • Quantum efficiency is found to be high. • These glasses are suitable materials for generating white light. - Abstract: Structural, thermal, optical properties and simulation of white light of Dy{sup 3+}-doped tellurite glasses of composition TTWD: (75 ? x)TeO{sub 2} ? 10TiO{sub 2} ? 15WO{sub 3} ? xDy{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1.0 and 2.0 mol%) were investigated. Raman spectra revealed that the glass contains TeO{sub 4}, TeO{sub 3}, WO{sub 4} and WO{sub 6} units. Differential scanning calorimetry (DSC) measurements were carried out to measure the glass transition temperature of all the glasses. From the optical absorption spectra, luminescence spectra and using the Judd–Ofelt (JO) analysis, we estimated the radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes. The decay curves at lower concentrations are exponential while they show a non-exponential behavior at higher concentrations (?0.5 mol%) due to energy transfer processes. The effective lifetime for the {sup 4}F{sub 9/2} level decreases with increase in Dy{sub 2}O{sub 3} concentration for the glasses under investigation. The non-exponential decay curves could fit well to the Inokuti–Hirayama (IH) model with S = 6, indicating that the nature of interaction responsible for energy transfer is of dipole–dipole type. Simulation of white light is examined with varying concentration and the results indicate that these glasses are suitable for white light emitting diode applications.

  14. Morphology and orientation of ?-BaB2O4 crystals patterned by laser in the inside of samarium barium borate glass

    NASA Astrophysics Data System (ADS)

    Nishii, Akihito; Shinozaki, Kenji; Honma, Tsuyoshi; Komatsu, Takayuki

    2015-01-01

    Nonlinear optical ?-BaB2O4 crystal lines (?-BBO) were patterned in the inside of 8Sm2O3-42BaO-50B2O3 glass by irradiations of continuous-wave Yb:YVO4 lasers with a wavelength of 1080 nm (power: P=0.8-1.0 W, scanning speed: S=0.2-2.5 ?m/s), in which the laser focal position was moved gradually from the surface to the inside. The morphology, size, and orientation of ?-BBO crystals were examined from polarization optical microscope and birefringence imaging observations. It was demonstrated that c-axis oriented ?-BBO crystals with long lengths (e.g., 20 mm) were patterned in the inside of the glass. The morphology of ?-BBO in the cross-section of lines was a rectangular shape with rounded corners, and the volume of ?-BBO formed increased with increasing laser power and with decreasing laser scanning speed. The maximum depth in the inside from the surface for ?-BBO patterning increased with increasing laser power, e.g., Dmax~100 ?m at P=0.8 W, Dmax~170 ?m at P=0.9 W, and Dmax~200 ?m at P=1 W. The present study proposes that the laser-induced crystallization opens a new door for applied engineering in glassy solids.

  15. Fabrication and characterization of carbon/oxygen-implanted waveguides in Nd3+-doped phosphate glasses

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Xiao; Xu, Jun; Fu, Li-Li; Zheng, Rui-Lin; Zhou, Zhi-Guang; Li, Wei-Nan; Guo, Hai-Tao; Lin, She-Bao; Wei, Wei

    2015-06-01

    Optical planar waveguides in Nd3+-doped phosphate glasses are fabricated by a 6.0-MeV carbon ion implantation with a dose of 6.0×1014 ions/cm2 and a 6.0-MeV oxygen ion implantation at a fluence of 6.0×1014 ions/cm2, respectively. The guided modes and the corresponding effective refractive indices were measured by a modal 2010 prism coupler. The refractive index profiles of the waveguides were analyzed based on the stopping and range of ions in matter and the RCM reflectivity calculation method. The near-field light intensity distributions were measured and simulated by an end-face coupling method and a finite-difference beam propagation method, respectively. The comparison of optical properties between the carbon-implanted waveguide and the oxygen-implanted waveguide was carried out. The microluminescence and Raman spectroscopy investigations reveal that fluorescent properties of Nd3+ ions and glass microstructure are well preserved in the waveguide region, which suggests that the carbon/oxygen-implanted waveguide is a good candidate for integrated photonic devices.

  16. White light emitting Ho{sup 3+}-doped CdS nanocrystal ingrained glass nanocomposites

    SciTech Connect

    Dey, Chirantan; Karmakar, Basudeb; Goswami, Madhumita

    2015-02-23

    We report the generation of white light from Ho{sup 3+} ion doped CdS nanocrystal ingrained borosilicate glass nanocomposites prepared by the conventional melt-quench method. Near visible 405?nm diode laser excited white light emission is produced by tuning the blue emission from the Ho{sup 3+} ions, green band edge, and orange-red surface-state emissions of the nanocrystalline CdS, which are further controlled by the size of the nanocrystals. The absorption and emission spectra evidenced the excitation of Ho{sup 3+} ions by absorption of photons emitted by the CdS nanocrystals. The high color rendering index (CRI?=?84–89) and befitting chromaticity coordinates (x?=?0.308–0.309, y?=?0.326–0.338) of white light emission, near visible harmless excitation wavelength (405?nm), and high absorbance values at excitation wavelength point out that these glass nanocomposites may serve as a prominent candidate for resin free high power white light emitting diodes.

  17. Spectroscopic properties of Er3+ doped lead telluroborate glasses for 1.5 ?m broadband amplifiers

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R.; Arunkumar, S.; Vijayakumar, M.; Marimuthu, K.

    2014-04-01

    Er3+ doped lead telluroborate glasses (xEPTB) with the composition 25B2O3-(25-x)TeO2-25PbO-10Bi2O3-15CdO-xEr2O3 (where x=0.1, 0.5, 1 and 2 wt%) have been prepared and characterised using NIR luminescence and decay measurements for 1.5 ?m broadband amplifier applications. Judd-Ofelt intensity parameters have been derived to predict radiative properties of the 4I13/2?4I15/2 emission transition. The larger values of stimulated emission cross-section (?P), FWHM, gain bandwidth (?G), radiative lifetime (?cal), quantum efficiency (?) of the 1EPTB glass suggest their potential use in broadband amplifiers. The effect of RE ion concentration and OH- content on the lifetime of 4I13/2?4I15/2 transition and the energy transfer mechanism of Er3+ ions have also been discussed and reported in the present study.

  18. Energy transfer and energy level decay processes in Tm{sup 3+}-doped tellurite glass

    SciTech Connect

    Gomes, Laercio; Lousteau, Joris; Milanese, Daniel; Scarpignato, Gerardo C.; Jackson, Stuart D.

    2012-03-15

    The primary excited state decay and energy transfer processes in singly Tm{sup 3+}-doped TeO{sub 2}:ZnO:Bi{sub 2}O{sub 3}:GeO{sub 2} (TZBG) glass relating to the {sup 3}F{sub 4}{yields}{sup 3}H{sub 6}{approx}1.85 {mu}m laser transition have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the {sup 3}H{sub 4} manifold at 794 nm, the {sup 3}H{sub 5} manifold at 1220 nm, and {sup 3}F{sub 4} manifold at 1760 nm has established that the {sup 3}H{sub 5} manifold is entirely quenched by multiphonon relaxation in tellurite glass. The luminescence from the {sup 3}H{sub 4} manifold with an emission peak at 1465 nm suffers strong suppression due to cross relaxation that populates the {sup 3}F{sub 4} level with a near quadratic dependence on the Tm{sup 3+} concentration. The {sup 3}F{sub 4} lifetime becomes longer as the Tm{sup 3+} concentration increases due to energy migration and decreases to 2.92 ms when [Tm{sup 3+}] = 4 mol. % as a result of quasi-resonant energy transfer to free OH{sup -} radicals present in the glass at concentrations between 1 x 10{sup 18} cm{sup -3} and 2 x 10{sup 18} cm{sup -3}. Judd-Ofelt theory in conjunction with absorption measurements were used to obtain the radiative lifetimes and branching ratios of the energy levels located below 25 000 cm{sup -1}. The spectroscopic parameters, the cross relaxation and Tm{sup 3+}({sup 3}F{sub 4}) {yields} OH{sup -} energy transfer rates were used in a numerical model for laser transitions emitting at 2335 nm and 1865 nm.

  19. Gold nanoparticles assisted structural and spectroscopic modification in Er3+-doped zinc sodium tellurite glass

    NASA Astrophysics Data System (ADS)

    Awang, Asmahani; Ghoshal, S. K.; Sahar, M. R.; Arifin, R.

    2015-04-01

    Achieving enhanced spectroscopic properties of rare earth doped inorganic glasses by embedding metallic nanoparticles of controlled sizes is a challenging task. We report the gold (Au) NPs assisted modifications in structural and spectroscopic properties of melt-quench synthesized Er3+ doped zinc sodium tellurite glass. The growth of NPs is stimulated via time varying heat treatment at 300 °C. XRD patterns confirm the amorphous nature of glasses and TEM images manifest the growth of gold NPs with sizes between 6.1 and 10.7 nm. The heat treatment time dependent variations in physical properties are ascribed to the alteration in bonding of non-bridging oxygen ions. The UV-VIS-NIR spectra reveal six absorption peaks centered at 488, 523, 655, 800, 973 and 1533 nm corresponding to the transition from ground state of 4I15/2 to 4F7/2, 2H11/2, 4F9/2, 4I9/2,4I11/2, and 4I13/2 excited states of Er3+ ions, respectively. Surface plasmon resonance (SPR) bands are observed in the range of 618-632 nm. Judd-Ofelt analyses demonstrate a significant increase of spectroscopic quality factors (0.86-1.05) and branching ratio (0.62-92.38%). The up-conversion emission spectra of Er3+ exhibit three prominent peaks of reasonable green (502 nm), a moderate green (546 nm) and a strong red (629 nm). An enhancement in the red band luminescence intensity by a factor of 8.19 and 8.54 times are achieved for 2 and 4 h of heat treatments, respectively. This enhancement is attributed to the SPR effects of gold NPs producing an intense local field in the proximity of Er3+ ions and subsequent energy transfer between RE ions and NPs. The FTIR spectra display the presence of vibrational modes for ZnO4 bonds, Te-O bond in TeO3 (tp) and TeO4 (tbp) units and the hydroxyl groups. Excellent features of the results suggest that our method constitute a basis for tunable growth of gold NPs which is exceedingly useful for the optimization of optical and structural properties.

  20. Development and characterization of a Ti-doped haploandesite glass standard for Ti-in-zircon geothermometry (Invited)

    NASA Astrophysics Data System (ADS)

    Hanchar, J. M.; Shimizu, N.; Fournelle, J.; Fisher, C. M.; Buchanan, A.; Piccoli, P. M.; Hayward, C.; Bowring, S. A.

    2010-12-01

    There have been many papers published in the past five years that use Ti-in-zircon thermometry to constrain the crystallization temperature of zircon in a wide variety of geologic systems. A crucial component of this line of research that is currently lacking is well characterized and widely available quality control (also referred to as secondary standards) standards that can be used to better constrain the accuracy of the Ti-in-zircon measurements. To address this problem, we have developed a series of four Ti-doped haploandesite glasses (nominal composition SiO2 = 59.5%; Al2O3 = 16.0%; MgO = 7.5%; CaO = 10.0%; and Na2O= 7.0%) for use as potential quality control standards. These glasses were produced using all high purity reagents, to which different amounts of TiO2 were added. The haploandesite glasses were synthesized in a Deltech MoSi2 vertical tube furnace in a platinum crucible by slowly heating the oxide and carbonate starting materials from 600°C to 1150°C at 50°C/hour to allow for complete decarbonation, and then ramped from 1150°C to 1450°C at 100°C/hour. Following an initial fusion at 1450°C for two hours, each of the glasses were quenched in water and crushed to a fine powder. The glasses were then fused at 1450°C, quenched, and crushed, two additional times to ensure homogeneity of the final glass material. Preliminary in situ LA-ICPMS analyses indicate that the glasses have the following Ti compositions: Glass 1: 1017 ppm; Glass 2: 221 ppm; Glass 3: 63 ppm; and Glass 4: 29 ppm. These glasses will be thoroughly characterized using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), secondary ion mass spectrometry (SIMS), and electron probe microanalyzer (EPMA), and then made available to the geologic community. In addition to being used primarily as quality control standards, it should also be possible to use, Glass 1, for example, as a calibration standard and then one of the other lower Ti content glasses as a quality control standard. Using this glass synthesis method, approximately 10 g of Glass 1 is available, and approximately 5 grams of the other three glasses are available, for distribution.

  1. Uniform upconversion in high-concentration Er{sup 3+}-doped soda lime silicate and aluminosilicate glasses

    SciTech Connect

    Hehlen, M.P.; Cockroft, N.J.; Gosnell, T.R.; Bruce, A.J.; Nykolak, G.; Shmulovich, J.

    1997-06-01

    Uniform upconversion in erbium-doped silicate glasses is investigated as a function of glass composition, concentration, and fabrication method. Comparisons of upconversion coefficients are made among soda lime silicate and aluminosilicate bulk glasses and soda lime silicate waveguides. Comparisons are also made with studies performed by other researchers. The results indicate that both the composition and the preparation method of the glass affect the value of the upconversion coefficient, with as much as a factor-of-4 variation observed at fixed Er{sup 3+} concentration. Values of the upconversion coefficient are found to be consistent with the F{umlt o}rster{endash}Dexter microscopic model. {copyright} {ital 1997} {ital Optical Society of America}

  2. Cluster-glass behavior induced by local moment doping in the itinerant ferromagnet Sc3.1In

    NASA Astrophysics Data System (ADS)

    Svanidze, E.; Morosan, E.

    2013-08-01

    In the presented work, Sc3.1In, a weak itinerant ferromagnet with no magnetic constituents, is doped with Er3+ local moment ions, to form (Sc1-xErx)3.1In. As x increases, the Weiss-like temperature ? stays positive and nearly triples up to x=0.10. Moreover, Er doping of as little as x=0.02 induces a cluster-glass state, which persists up to x=0.10, as evidenced by dc and ac susceptibility measurements, and confirmed by the Vogel-Fulcher analysis.

  3. FTIR and optical assessment of zinc doped calcium phospho-borosilicate sol-gel glasses/glass-ceramics

    NASA Astrophysics Data System (ADS)

    Kumar, V.; Arora, N.; Pandey, O. P.; Kaur, G.

    2015-08-01

    CaO-P2O5-ZnO-SiO2-B2O3 glasses with varying compositions of calcium oxide and phosphorous oxide are synthesized using sol-gel technique. The glasses are heat-treated for a duration of 10 h at 500°C to obtain the glass-ceramics. The glass-ceramics and glasses are characterized using Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. Extinction coefficients, attenuation coefficients and dielectric constant have been obtained for all the glasses as well as glass ceramics. The results are discussed in light of non-bridging oxygens (NBO) and heat-treatment of glasses. In addition to this, the effect of calcium and phosphorous on the infra-red spectra has been analysed thoroughly.

  4. Effect of boron doping on optical properties of sol-gel based nanostructured zinc oxide films on glass

    SciTech Connect

    Jana, Sunirmal; Vuk, Angela Surca; Mallick, Aparajita; Orel, Boris; Biswas, Prasanta Kumar

    2011-12-15

    Graphical abstract: Room temperature fine structured UV-vis PL emissions (a) as phonon replicas in 1 at.% boron doped film originated from LO phonon evidenced from Near Grazing Incidence Angle (NGIA) IR spectral study (b). Highlights: Black-Right-Pointing-Pointer Sol-gel based boron doped nanostructured ZnO thin films deposited on pure silica glass using crystalline boric acid as boron source. Black-Right-Pointing-Pointer Observed first time, room temperature fine structured PL emissions in 1 at.% doped film as phonon replicas originated from LO phonon (both IR and Raman active). Black-Right-Pointing-Pointer Boron doping controls the LO phonon energy in addition to visible reflection, band gap and grain size. Black-Right-Pointing-Pointer The films possessed mixed crystal phases with hexagonal as major phase. -- Abstract: Boron doped zinc oxide thin films ({approx}80 nm) were deposited onto pure silica glass by sol-gel dip coating technique from the precursor sol/solution of 4.0 wt.% equivalent oxide content. The boron concentration was varied from 0 to 2 at.% w.r.t. Zn using crystalline boric acid. The nanostructured feature of the films was visualized by FESEM images and the largest cluster size of ZnO was found in 1 at.% boron doped film (B1ZO). The presence of mixed crystal phases with hexagonal as major phase was identified from XRD reflections of the films. Particle size, optical band gap, visible specular reflection, room temperature photoluminescence (PL) emissions (3.24-2.28 eV), infra-red (IR) and Raman active longitudinal optical (LO) phonon vibration were found to be dependent on dopant concentration. For the first time, we report the room temperature fine structured PL emissions as phonon replicas originated from the LO phonon (both IR and Raman active) in 1 at.% boron doped zinc oxide film.

  5. Homogeneity of bismuth-distribution in bismuth-doped alkali germanate laser glasses towards superbroad fiber amplifiers.

    PubMed

    Zhao, Yanqi; Wondraczek, Lothar; Mermet, Alain; Peng, Mingying; Zhang, Qinyuan; Qiu, Jianrong

    2015-05-01

    Compared to rare-earth doped glasses, bismuth-doped glasses hold promise for super-broadband near-infrared (NIR) photoemission and potential applications in optical amplification. However, optically active bismuth centers are extremely sensitive to the properties of the surrounding matrix, and also to processing conditions. This is strongly complicating the exploitation of this class of materials, because functional devices require a very delicate adjustment of the redox state of the bismuth species, and its distribution throughout the bulk of the material. It also largely limits some of the conventional processing routes for glass fiber, which start from gas phase deposition and may require very high processing temperature. Here, we investigate the influence of melting time and alkali addition on bismuth-related NIR photoluminescence from melt-derived germanate glasses. We show that the effect of melting time on bismuth-related absorption and NIR photoemission is primarily through bismuth volatilization. Adding alkali oxides as fluxing agents, the melt viscosity can be lowered to reduce either the glass melting temperature, or the melting time, or both. At the same time, however, alkali addition also leads to increasing mean-field basicity, what may reduce the intensity of bismuth-related NIR emission. Preferentially using Li2O over Na2O or K2O presents the best trade-off between those above factors, because its local effect may be adverse to the generally assumed trend of the negative influence of more basic matrix composition. This observation provides an important guideline for the design of melt-derived Bi-doped glasses with efficient NIR photoemission and high optical homogeneity. PMID:25969328

  6. Mechanisms of the refractive index change in femtosecond laser-irradiated Au{sup 3+}-doped silicate glasses

    SciTech Connect

    Zhao Quanzhong; Qiu Jianrong; Jiang Xiongwei; Zhao Chongjun; Zhu Congshan

    2004-12-15

    We report on the refractive index change in Au{sup 3+}-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 450 deg. C 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 300 deg. C, and precipitation of gold nanoparticles after annealing at high temperature. The mechanisms of the observed phenomena are discussed.

  7. Three-photon-excited upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation.

    PubMed

    Zeng, Huidan; Song, Juan; Chen, Danping; Yuan, Shuanglong; Jiang, Xiongwei; Cheng, Ya; Yang, Yunxia; Chen, Guorong

    2008-04-28

    We report on the bluish green upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation. The dependence of the fluorescence intensity on the pump power density of laser indicates that the conversion of infrared irradiation to visible emission is dominated by three-photon excitation process. We suggest that the charge transfer from O(2-) to Nb(5+) can efficiently contribute to the bluish green emission. The results indicate that transition metal ions without d electrons play an important role in fields of optics when embedded into silicate glass matrix. PMID:18545353

  8. Transition metal and rare earth quad-doped photovoltaic phosphate glasses toward raising a-SiC:H solar cell performance

    NASA Astrophysics Data System (ADS)

    Song, P.; Zhang, C. M.; Zhu, P. F.

    2016-01-01

    Efficiency enhancement of a hydrogenated amorphous-silicon carbide (a-SiC:H) solar cell using downshifting and upconversion of photovoltaic (PV) glasses doped with transition metal (TM) ions and rare earth (RE) ions are investigated. P2O5-Li2O-Al2O3-Sb2O3-MnO-Yb2O3-Er2O3 glass doped with Sb3+-Mn2+-Yb3+-Er3+ ions is prepared and the PV glass is placed on an a-SiC:H solar cell. The performance of the cell in combination with the PV glass is simulated and measured, and the results show that the theoretical and experimental efficiencies are both enhanced compared to the bare one. The potential of TM-RE quad-doped glasses for improving the efficiency of a-SiC:H PV modules are explored.

  9. Structural investigations of lead germanosilicate glasses doped with Nb2O5 by means of spectroscopic and dielectric studies

    NASA Astrophysics Data System (ADS)

    Narendrudu, T.; Suresh, S.; Yusub, S.; Kumar, A. Suneel; Rajyasree, Ch.; Rao, M. V. Sambasiva; Kumar, V. Ravi; Rao, D. Krishna

    2015-10-01

    The transparent glasses with composition 30PbO-10GeO2-(60-x)SiO2-xNb2O5 (mol%) (0 ? x ? 2.5) are prepared by conventional melt quenching technique. The amorphous nature of the prepared glasses is characterized by XRD. The spectroscopic studies such as optical absorption, FTIR, Raman spectra were carried out at room temperature on these glasses. Besides this electrical properties, like dielectric constant ?', loss tan ?, ac conductivity ?ac etc., were also investigated over a moderately wide range of frequency (103-106 Hz) and temperature (30-300 °C). The optical absorption spectrum of the prepared glasses has exhibited absorption bands around 325 nm and 340 nm and these are due to the triplet - singlet electronic transition of Ge2+ state presents in the glass matrix as conversion of GeO2 into GeO is much easier rather than SiO2. From FTIR spectra of as prepared glasses, it is noticed that the intensity of octahedral NbO6 structural units is found to increase up to 2 mol% of Nb2O5 there after it is observed to decrease. It is also supported by Raman shift of NbO6 structural units observed around 650 and 930 cm-1. The analysis of electrical studies is also revealed that the conductivity of prepared glasses is found to increase gradually up to 2 mol% of Nb2O5 beyond this concentration it is observed to decrease. When the spectroscopic investigations are coupled with electrical studies it is concluded that the glass samples doped with 2 mol% of Nb2O5 are found to exhibit good semiconducting nature among the prepared glasses. Such glasses are suitable for fabrication of solid state devices.

  10. Preparation of CuCl microcrystals-doped SiO2 glass by co-sputtering method

    NASA Astrophysics Data System (ADS)

    Takami, Seiichi; Egashira, Yasuyuki; Honma, Itaru; Komiyama, Hiroshi

    1996-02-01

    CuCl microcrystals-doped SiO2 glass is prepared by the co-sputtering method using extremely pure CuCl source materials as well as a pure SiO2 target. Low temperature optical absorption spectra (2 K) show the shift of the Z1,2 as well as the Z3 exciton peaks, indicating that the mean radius of the microcrystals is about 5.8 nm.

  11. Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber

    PubMed Central

    Li, Wentao; Chen, Danping; Qinling, Zhou; Hu, Lili

    2015-01-01

    We have demonstrated a 45??m core diameter Neodymium-doped all-solid silicate glass photonic crystal fiber laser with a single mode laser output. The structure parameters and modes information of the fiber are both demonstrated by theoretical calculations using Finite Difference Time Domain (FDTD) method and experimental measurements. Maximum 0.8?W output power limited by launched pump power has been generated in 1064?nm with laser beam quality factor M2 1.18. PMID:26205850

  12. Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber.

    PubMed

    Li, Wentao; Chen, Danping; Qinling, Zhou; Hu, Lili

    2015-01-01

    We have demonstrated a 45??m core diameter Neodymium-doped all-solid silicate glass photonic crystal fiber laser with a single mode laser output. The structure parameters and modes information of the fiber are both demonstrated by theoretical calculations using Finite Difference Time Domain (FDTD) method and experimental measurements. Maximum 0.8?W output power limited by launched pump power has been generated in 1064?nm with laser beam quality factor M(2) 1.18. PMID:26205850

  13. Study of gamma induced defects in Nd doped phosphate glass using UV-Vis spectrophotometer and photophysics beamline on INDUS-1

    E-print Network

    Rai, V N; Jagtap, B N

    2014-01-01

    Nd doped phosphate glasses have been studied before and after gamma irradiation in order to understand the effect of glass composition and radiation induced defects on the optical properties of glasses. UV, Vis absorption and photoluminescence spectra of these glasses are found strongly dependent on the composition of glass matrix, particularly on the ratio of oxygen (O) and neodymium (Nd) concentration obtained from energy dispersive X-ray spectroscopic (EDX) measurement. Gamma irradiation of glass modifies the transmission below 700 nm due to generation of some new absorption bands corresponding to different types of defects. Observations indicate toward possibility of change in the valence state of Nd3+ to Nd2+ and generation of oxygen vacancies in glass matrix. EDX and X-ray photoelectron spectroscopic (XPS) measurements indicate change in the composition of glasses particularly decrease in the relative concentration of oxygen in glass samples after gamma irradiation.

  14. Electrochromic characteristics of niobium-doped titanium oxide film on indium tin oxide/glass by liquid phase deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Lee, Chia-Jung

    2015-10-01

    Ammonium hexafluorotitanate and boric acid aqueous solutions were used as precursors for the growth of titanium oxide films on indium tin oxide (ITO)/glass substrate. For as-grown titanium oxide film used in an electrochromic device, Li+ ions from electrolyte will be trapped to hydroxyl groups and degrade the electrochromic durability during the cyclic voltammogram characterization. For niobium doped titanium oxide film, lower growth rate from more HF incorporation from the niobium doped solution and rougher surface morphology from the formation of nanocrystals were obtained. However, niobium doping reduces hydroxyl groups and the electrochromic durability is enhanced from 5 × 103 to 1 × 104 times. The transmittance is enhanced from 37 to 51% at the wavelength of 550 nm.

  15. Optical properties of undoped and Al-doped ZnO nanostructures grown from aqueous solution on glass substrate

    NASA Astrophysics Data System (ADS)

    Mazilu, M.; Tigau, N.; Musat, V.

    2012-09-01

    The paper presents the optical properties of undoped and aluminium-doped zinc oxide nanostructures grown on glass substrates using the hydrothermal method. The obtained ZnO-based nanostructures showed optical transmittance over 75% and low reflectance in the visible domain. The increasing of optical transmittance of Al-doped ZnO nanostructures with increased doping concentrations was observed. The optical constants such as index of refraction, extinction coefficient, dielectric constants and optical conductivity were determined using the transmission and the reflection at normal incidence of light in the wavelength range of 200-1100 nm. The band gap broadens with increasing dopant concentration from 2% to 4%. The obtained nanostructured layers with size in the range of subwavelength of visible light can act as anti-reflective coating that reduces reflectance based on the Moth Eye principle.

  16. Luminescence of Eu(3+) doped SiO2 Thin Films and Glass Prepared by Sol-gel Technology

    NASA Technical Reports Server (NTRS)

    Castro, Lymari; Jia, Weiyi; Wang, Yanyun; Santiago, Miguel; Liu, Huimin

    1998-01-01

    Trivalent europium ions are an important luminophore for lighting and display. The emission of (5)D0 to (7)F2 transition exhibits a red color at about 610 nm, which is very attractive and fulfills the requirement for most red-emitting phosphors including lamp and cathode ray phosphorescence materials. Various EU(3+) doped phosphors have been developed, and luminescence properties have been extensively studied. On the other hand, sol-gel technology has been well developed by chemists. In recent years, applications of this technology to optical materials have drawn a great attention. Sol-gel technology provides a unique way to obtain homogeneous composition distribution and uniform doping, and the processing temperature can be very low. In this work, EU(3+) doped SiO2 thin films and glasses were prepared by sol-gel technology and their spectroscopic properties were investigated.

  17. EPR and optical study of Yb3+-doped ?-PbF2 single crystals and nanocrystals of glass-ceramics

    NASA Astrophysics Data System (ADS)

    Dantelle, G.; Mortier, M.; Goldner, Ph; Vivien, D.

    2006-08-01

    ?-PbF2 single crystals doped with YbF3 (0.2% and 2%) were studied by x-ray diffraction (XRD), electron paramagnetic resonance (EPR) and optical spectroscopy. EPR revealed the presence of only one kind of paramagnetic ion Yb3+, in a cubic symmetry site. The optical absorption, emission and excitation spectra enabled us to identify the transitions attributed to Yb3+ in the cubic site and to determine its energy level diagram. Site-selective laser spectroscopy also evidenced the presence of another type of Yb3+ ions, undetectable by classical EPR. This second type, which dominates in the 2%-doped crystal and exhibits cooperative luminescence, was attributed to Yb3+ ions forming clusters. Transparent oxyfluoride glass-ceramics, containing ?-Pb1-yYbyF2+y nanocrystallites, were also synthesized and studied by XRD, EPR and optical spectroscopy. Two types of Yb3+ ions were found, as in ?-PbF2 single crystals. The optical properties of the oxyfluoride glass-ceramics turn out to be similar to those of ytterbium activated ?-PbF2 single crystals. Moreover, the Yb environments found in PbF2 single crystals seem to already occur in the parent glass. Therefore, these materials are expected to be good laser media, like the rare-earth doped fluorite crystals, either in bulk or fibre form.

  18. Luminescent properties of Eu2+-doped BaGdF5 glass ceramics a potential blue phosphor for ultra-violet light-emitting diode

    NASA Astrophysics Data System (ADS)

    Zhang, Weihuan; Zhang, Yuepin; Ouyang, Shaoye; Zhang, Zhixiong; Wang, Qian; Xia, Haiping

    2015-01-01

    Eu2+ doped transparent oxyfluoride glass ceramics containing BaGdF5 nanocrystals were successfully fabricated by melt-quenching technique under a reductive atmosphere. The structure of the glass and glass ceramics were investigated by differential scanning calorimetry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The luminescent properties were investigated by transmission, excitation, and emission spectra. The decay time of the Gd3+ ions at 312 nm excited with 275 nm were also investigated. The results of XRD and TEM indicated the existence of BaGdF5 nanocrystals in the transparent glass ceramics. The excitation spectra of Eu2+ doped glass ceramics showed an excellent overlap with the main emission region of an ultraviolet light-emitting diode (UV-LED). Compared with the as-made glass, the emission of glass ceramics is much stronger by a factor of increasing energy transfer efficiency from Gd3+ to Eu2+ ions, the energy transfer efficiency from Gd3+ to Eu2+ ions was discussed. In addition, the chromaticity coordinates of glass and glass ceramics specimens were also discussed, which indicated that the Eu2+ doped BaGdF5 glass ceramics may be used as a potential blue-emitting phosphor for UV-LED.

  19. Luminescent properties of Eu{sup 2+}-doped BaGdF{sub 5} glass ceramics a potential blue phosphor for ultra-violet light-emitting diode

    SciTech Connect

    Zhang, Weihuan; Zhang, Yuepin Ouyang, Shaoye; Zhang, Zhixiong; Wang, Qian; Xia, Haiping

    2015-01-14

    Eu{sup 2+} doped transparent oxyfluoride glass ceramics containing BaGdF{sub 5} nanocrystals were successfully fabricated by melt-quenching technique under a reductive atmosphere. The structure of the glass and glass ceramics were investigated by differential scanning calorimetry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The luminescent properties were investigated by transmission, excitation, and emission spectra. The decay time of the Gd{sup 3+} ions at 312?nm excited with 275?nm were also investigated. The results of XRD and TEM indicated the existence of BaGdF5 nanocrystals in the transparent glass ceramics. The excitation spectra of Eu{sup 2+} doped glass ceramics showed an excellent overlap with the main emission region of an ultraviolet light-emitting diode (UV-LED). Compared with the as-made glass, the emission of glass ceramics is much stronger by a factor of increasing energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions, the energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions was discussed. In addition, the chromaticity coordinates of glass and glass ceramics specimens were also discussed, which indicated that the Eu{sup 2+} doped BaGdF{sub 5} glass ceramics may be used as a potential blue-emitting phosphor for UV-LED.

  20. [Microstructure and spectral property of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine contents].

    PubMed

    Lin, Le-Jing; Ren, Guo-Zhong; Chen, Min-Peng; Liu, Yang

    2009-12-01

    The microstructure and spectral properties of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine content were reported. Two samples with the same initial contents (50SiO2-45PbF2-5PbO-1ErF3) were prepared under the different preparation parameters. The final fluorine contents were detected by a fluoride ion selective electrode. The results shows that the final fluorine contents increase by covering crucibles with corundum lid during melt. The samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), absorption spectra and upconversion luminescence spectra. The results show that PbF2 crystals were precipitated in the sample with high fluorine content before heat treatment. And the PbF2 crystals precipitated inside the glass matrix are spherical with diameters of approximately 10-15 nm in size from the high resolution TEM micrograph. The absorption spectra, J-O parameters and the upconversion spectra show that the Er3+ ions were located in crystalline and vitreous mixed states. It is different from the sample with low fluorine content which is completely amorphous. After heat treatment, Er3+ ions that remain in the glassy phase entered into fluoride nanocrystals in the sample with high fluorine content. The fluorine environment decreases non-radiative transfer which eases the upconversion processes. Hence, the upconversion luminescence intensity of Er3+ ions in the high fluorine content sample after heat treatment is much stronger than that in the precursor sample. PMID:20210134

  1. The spectroscopic properties of Er(3+)-doped TeO(2)-Nb(2)O(5) glasses with high mechanical strength performance.

    PubMed

    Dai, Shixun; Wu, Jialu; Zhang, Junjie; Wang, Guonian; Jiang, Zhonghong

    2005-11-01

    (100-x)TeO(2)-xNb(2)O(5) (x=5-20) niobic tellurite glasses doped with 0.5 mol.% Er(2)O(3) were synthesized, and their thermal, mechanical, and spectroscopic properties were measured and compared to the properties of the typical 75TeO(2)-20ZnO-5Na(2)O (TZN) tellurite glass. The refractive index (n(d)), density (rho), and glass transition temperature (T(g)) of bulk glasses increase with the Nb(2)O(5) content. The Vickers microhardness (H(v)) of bulk glass in niobic tellurite glasses also increases with the Nb(2)O(5) content. The values (2.5-3.2GPa) of H(v) in the niobic tellurite glasses are 47-88% larger than that (1.7GPa) in TZN glass. The effect of Nb(2)O(5) content on absorption spectra, the Judd-Ofelt parameters Omega(t) (t=2, 4, 6), fluorescence spectra and the lifetimes of Er(3+):I(13/2) level were also investigated, and the stimulated emission cross-section was calculated from McCumber theory. With increasing Nb(2)O(5) content in the glass composition, the Omega(t) (t=2, 4, 6) parameters, fluorescence full width at half maximum (FWHM) of I(13/2) of Er(3+) increase, while the (4)I(13/2) lifetimes of Er(3+) decreases. Compared with TZN glass, the gain bandwidth properties of Er(3+)-doped TeO(2)-Nb(2)O(5) glass is much larger than in tellurite glass based TeO(2)-ZnO-Na(2)O system, bismush-based glass, germanate, and silicate glasses, which indicates that TeO(2)-Nb(2)O(5) glasses are better choice as a practical available host material for broadband Er(3+)-doped amplifier. PMID:16257745

  2. Judd-Ofelt analysis and radiative properties of the Sm3+ centres in Li2B4O7, CaB4O7, and LiCaBO3 glasses

    NASA Astrophysics Data System (ADS)

    Kindrat, I. I.; Padlyak, B. V.; Lisiecki, R.

    2015-11-01

    The spectroscopic and luminescence properties of a series Sm-doped Li2B4O7, CaB4O7, and LiCaBO3 borate glasses are investigated using optical absorption, photoluminescence, and decay kinetics techniques as well as Judd-Ofelt (J-O) analysis. Borate glasses of high chemical purity and optical quality, doped with Sm2O3 in amounts of 0.5 and 1.0 mol.% were obtained from the corresponding polycrystalline compounds in the air atmosphere using standard glass synthesis technology. The J-O intensity parameters have been calculated using the spectral intensities of the Sm3+ absorption bands. Radiative properties such as transition probabilities, branching ratios, stimulated emission cross-sections, and radiative lifetimes are estimated for 4G5/2 ? 6HJ (J = 5/2, 7/2, 9/2, and 11/2) emission transitions of the Sm3+ ions. The luminescence kinetics of the Sm3+ centres are characterised by slightly non exponential decay with lifetime values, which depend on the basic glass composition and Sm impurity concentration. The measured lifetimes were compared with those calculated and quantum efficiencies have been estimated. The obtained high quantum efficiencies of emission transitions (?70%) and high quantum yields of luminescence (?14%) of the Sm3+ centres show that the investigated borate glasses belong to perspective luminescent and laser materials.

  3. M (Tm3+, Tb3+, Ho3+, Dy3+, Mn2+)-doped transparent fluorophosphate glasses for white light-emitting-diodes

    NASA Astrophysics Data System (ADS)

    Ming, Chengguo; Song, Feng; Qin, Yueting; Ren, Xiaobin; An, Liqun

    2014-06-01

    M-doped (M=Tm3+, Tb3+, Ho3+, Dy3+, Mn2+) transparent fluorophosphate glasses were prepared by a high temperature melting method. Excitation and emission spectra of the samples were investigated. Under near-ultraviolet excitation, the emission colors of the Tm3+-and Mn2+-doped samples are blue and red, respectively; the emission colors of the Tb3+-, Ho3+-, and Dy3+-doped samples are green; and the emission color of Tb3+/ Mn2+/Tm3+ tridoped fluorophosphate glass is white to the naked eye. Our research will be helpful in developing luminescent materials for white light-emitting-diodes.

  4. Spectroscopic properties of Er{sup 3+} doped glass ceramics containing Sr{sub 2}GdF{sub 7} nanocrystals

    SciTech Connect

    Qiao Xvsheng; Fan Xianping; Wang Minquan

    2006-09-11

    The Er{sup 3+} doped transparent oxyfluoride glass ceramics containing Sr{sub 2}GdF{sub 7} nanocrystals were prepared and their spectroscopic properties were discussed. The formation of Sr{sub 2}GdF{sub 7} nanocrystals in the glass ceramics was confirmed by x-ray diffraction. The split peaks of the upconversion and near infrared emission bands of the Er{sup 3+} doped glass ceramics can be observed. The upconversion luminescence intensity of Er{sup 3+} in the glass ceramics increased significantly with the increasing heat treated temperature. The luminescence decay curves and time-resolved spectra indicated that the lifetime of the {sup 4}S{sub 3/2} state of Er{sup 3+} in the glass ceramic was longer than that in the glass.

  5. Infrared Study of Er3+/Yb3+ Co-Doped GeO2-PbO-Bi2O3 Glass

    PubMed Central

    Bahari, Hamid-Reza; Sidek, Hj. A. A.; Adikan, Faisal Rafiq M.; Yunus, Wan M. M.; Halimah, Mohamed K.

    2012-01-01

    Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO2-PbO-Bi2O3 glass host doped with Er3+/Yb3+ ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi2O3 participate with PbO4 tetragonal pyramids and strongly distort BiO6 octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix. PMID:22942723

  6. Distribution of electric field and energy flux around the cracks on the surfaces of Nd-doped phosphate glasses

    SciTech Connect

    Zhang Lei; Huang Li; Fan Sijun; Bai Gongxun; Li Kefeng; Chen Wei; Hu Lili

    2010-12-10

    We simulate and calculate numerically the electromagnetic field and energy flux around a surface crack of an Nd-doped phosphate laser glass by using the finite-difference time-domain method. Because of a strong interference between the incident wave and the total internal reflections from the crack and the glass surface, the electric field is redistributed and enhanced. The results show that the electric-field distribution and corresponding energy flux component depend sensitively on the light polarization and crack geometry, such as orientation and depth. The polarization of the incident laser beam relative to the crack surfaces will determine the profile of the electric field around the crack. Under TE wave incidence, the energy flux peak is always inside the glass. But under TM wave incidence, the energy flux peak will be located inside the glass or inside the air gap. For both incident modes, the light intensification factor increases with the crack depth, especially for energy flux along the surface. Because cracks on the polished surfaces are the same as the roots extending down, the probability for much larger intensification occurring is high. The results suggest that the surface laser-damage threshold of Nd-doped phosphate may decrease dramatically with subsurface damage.

  7. Rare-earth ions doped heavy metal germanium tellurite glasses for fiber lighting in minimally invasive surgery.

    PubMed

    Yang, D L; Gong, H; Pun, E Y B; Zhao, X; Lin, H

    2010-08-30

    In Er(3+)/Yb(3+) codoped Na(2)O-ZnO-PbO-GeO(2)-TeO(2) (NZPGT) glass fiber, a clear and compact green upconversion amplified spontaneous emission (ASE) trace is observed, and the NZPGT glasses are proved to be a desirable candidate in fabricating low-phonon energy fiber. Intense green upconversion luminescence of Er(3+), balanced green and red upconversion emissions of Ho(3+), and dominant three-photon blue upconversion fluorescence of Tm(3+) have been represented. By varying the excitation power of 974 nm wavelength laser diode, a series of green and white fluorescences have been achieved in Tm(3+)/Er(3+)/Yb(3+) and Tm(3+)/Ho(3+)/Yb(3+) triply doped glass systems, respectively. These results reveal that high-intensity blue, green, and white upconversion ASE fluorescences, which can be adopted for lighting in minimally invasive photodynamic therapy and minimally invasive surgery, are reasonable to be expected in rare-earth doped NZPGT glass fibers. PMID:20940794

  8. Investigation of thermal stability and spectroscopic properties in Er3+/Yb3+ co-doped niobic tungsten tellurite glasses.

    PubMed

    Wang, Xuming

    2008-06-01

    A series of novel Er3+/Yb3+ co-doped 75TeO2-(25-x)Nb2O5-xWO3 (TNW: x=0, 3, 6, 9, 12, and 15 mol%) glasses have been prepared. Effect of WO3 on the thermal stability and spectroscopic properties of Er3+/Yb3+ co-doped niobic tellurite glasses have been investigated. With WO3 content increasing from 0 to 15 mol%, the fluorescence full width at half maximum (FWHM), the peak of stimulated emission cross-section (sigmaepeak), the measured lifetime (taum), and quantum efficiency (eta) change from 71 nm, 8.47x10(-21) cm2, 2.86 ms, 84.1% to 76 nm, 7.22x10(-21) cm2, 3.14 ms, 88.9%, respectively. The FWHM and sigmaepeak of Er3+ ions in different glass hosts were compared; the obtained data reveals that this new TNW4 glass may be a potentially useful candidate material host for broadband amplifiers. PMID:17988941

  9. Control of the local devitrification on oxyfluoride glass doped with Er{sup 3+} ions under diode laser irradiation

    SciTech Connect

    Gonzalez-Perez, S.; Martin, I. R.; Jaque, D.; Haro-Gonzalez, P.; Capuj, N.

    2010-11-15

    Temperature control of the devitrification process in an erbium doped oxyfluoride glass under laser irradiation is reported. The green upconversion emissions around 525 and 545 nm originated from the thermalized {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} levels were studied when the glass structure changes to glass ceramic during irradiation with a laser beam. Power dependence of the fluorescence intensity ratio was used to determine the temperature of the irradiated zone. The transition from glass to glass ceramic takes place under 2300 mW of laser power with an estimated temperature around 783 K. This result agrees with the one obtained in the samples devitrified under conventional furnace treatment. Therefore, the estimation of the temperature of the irradiated zone through the fluorescence intensity ratio method allows a controlled devitrification. Moreover, an irradiated line has been written in the glass showing an important diffusion of the Pb{sup 2+} and F{sup -} ions. These results confirm that nanocrystals have been created due to the laser action.

  10. Spectrometric analysis of different fluorophosphate glasses doped with Sm{sup 3+} ions for reddish-orange laser emission

    SciTech Connect

    Babu, S. Balakrishna, A. Ratnakaram, Y. C.

    2014-04-24

    Optical properties of Sm{sup 3+} doped different fluorophosphate glasses have been synthesized and discussed. The J- O intensity parameters ?{sub ?} (?= 2, 4, 6) from absorption spectra have been evaluated. No sharp edges are found in the absorption spectra, which confirm amorphous nature of present glass matrices. Various radiative parameters have been obtained from luminescence spectra for excited states to corresponding {sup 4}G{sub 5/2}?{sup 6}H{sub 5/2}, {sup 6}H{sub 7/2}, {sup 6}H{sub 9/2} and {sup 6}H{sub 11/2} transitions. The nature of decay curve analysis was performed for the {sup 4}G{sub 5/2} level. These glasses are expected to give interesting application in field of optical devices.

  11. Mid-infrared spectroscopic properties and energy transfer of Er3+/Yb3+ co-doped bismuth germanate glass.

    PubMed

    Zhao, Guoying; Wang, Shikai; Fan, Huiyan; Hu, Lili

    2013-01-15

    An Er3+/Yb3+ co-doped bismuth germanate glass is synthesized and analyzed. The radiative characteristics and mid-infrared spectroscopic properties are investigated under excitation of a conventional 980 nm laser diode. The prepared glass possesses higher spontaneous transition probability (68.82 s(-1)) and larger calculated emission cross-section (7.73×10(-21) cm2) corresponding to the 4I11/2?4I13/2 transition. The calculated energy migration coefficient (CDD) among Yb3+ ions is larger than the energy transfer coefficient (CDA) from Yb3+ to Er3+, indicating the energy transfer process assisted with energy migration. The excellent spectroscopic properties along with the outstanding thermal stability suggest that this glass may become an attractive host for developing solid state lasers operating in the mid-infrared range. PMID:23099159

  12. Spin glass behavior in hole- and electron-doped bismuth manganite single crystals

    NASA Astrophysics Data System (ADS)

    Zhao, B. C.; Huang, Y. N.; Hao, C. Y.; Kuang, G. L.; Sun, Y. P.

    2012-09-01

    The hole- and electron-doped bismuth manganites Bi0.55Ca0.45MnO3, Bi0.55Sr0.45MnO3 and Bi0.95Ce0.05MnO3 single crystals were grown using the flux-growth method. Their structural, magnetic and electrical transport properties have been compared studied. All samples show spin-glass magnetic behavior at low temperatures. In the immediate temperature region, an antiferromagnetic transition at TA and a charge-ordering state at TCO are observed for Bi0.55Ca0.45MnO3 crystal, whereas only an antiferromagnetic transition exists in Bi0.95Ce0.05MnO3 and Bi0.55Sr0.45MnO3 crystals. Bi0.55Ca0.45MnO3 and Bi0.55Sr0.45MnO3 samples show semiconducting transport behavior in the whole studied temperature range, whereas Bi0.95Ce0.05MnO3 is an insulator at room temperature. In addition, near TCO a positive magnetoresistance as large as 70.7% is observed for Bi0.55Ca0.45MnO3 sample under 5 T applied magnetic field. The obtained results may originate from the rotation of the polarized Bi-6s2 lone pair electrons in the magnetic field.

  13. Structural and Optical Studies on Dy{sup 3+} Doped Boro-Tellurite Glasses

    SciTech Connect

    Maheshvaran, K.; Marimuthu, K.

    2011-07-15

    Dy{sup 3+} doped Boro-tellurite glasses were prepared by following melt quenching technique with the chemical composition (69-x)H{sub 3}BO{sub 3}+xTeO{sub 2}+15Mg{sub 2}CO{sub 3}+15K{sub 2}CO{sub 3}+1Dy{sub 2}O{sub 3} by varying the tellurium dioxide content as (x = 0, 10, 20, 30 and 40 wt%). The structural and optical properties have been studied through FTIR, absorption and emission spectra. The UV-vis-NIR absorption spectra were used to calculate the oscillator strength, bonding parameters ({beta}-bar and {delta}), Judd-Ofelt intensity parameters ({Omega}{sub {lambda}}, {lambda} = 2, 4 and 6). The Y/B ratio has been discussed from the luminescence spectra for the excited states corresponding to {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 11/2}, {sup 6}H{sub 13/2}, and {sup 6}H{sub 15/2} transitions. The structural and optical properties corresponding to the compositional changes are discussed and reported.

  14. Lasing effects in new Nd3+-doped TeO2-Nb2O5-WO3 bulk glasses

    NASA Astrophysics Data System (ADS)

    Carreaud, J.; Labruyère, A.; Dardar, H.; Moisy, F.; Duclère, J.-R.; Couderc, V.; Bertrand, A.; Dutreilh-Colas, M.; Delaizir, G.; Hayakawa, T.; Crunteanu, A.; Thomas, P.

    2015-09-01

    This paper demonstrates for the first time continuous wave (cw) and pulsed lasing effects in a 75TeO2-20NbO2.5-5WO3 glass doped with 1 mol.% in Nd3+. It is divided into two parts: The first part treats all the aspects related to the elaboration and the characterization of the materials. Thus, glasses elaborated within the TeO2-Nb2O5-WO3 ternary system show a rather high glass transition temperature Tg ? 375 °C, with an excellent thermal stability of ?160 °C. Compared to glasses synthesized in either TeO2-Nb2O5 or TeO2-WO3 binary systems, glasses fabricated within such system show improved mechanical performances, with larger Young's modulus values. The structural characteristics of the samples, studied by Raman spectroscopy, are also presented. Linear optical properties (refractive index and extinction coefficient) are accessed by spectroscopic ellipsometry. As well, the optical transmission of the various bulk glasses is measured, in the case of both uncoated and coated glasses. In particular, specific anti-reflective coatings at 808 nm (laser diode pump wavelength) and 1064 nm (laser emission wavelength) are respectively deposited on the two surfaces of the sample in order to minimize the losses due to Fresnel reflections at the two glass/air interfaces. In addition, another specific surface treatment (Rmax at 1064 nm) was employed to serve as the back mirror of the laser cavity. The optical transmission data testified to the real efficiency of all these coatings. Finally, the photoluminescence properties (emission and excitation spectra, and luminescence decay curve) of the Nd3+-doped glasses, measured at room temperature for bulk samples, and as a function of temperature for powder glasses, are discussed. The second part is focused on evidencing (cw) and pulsed lasing effects in such coated bulk lasers. Cylindric samples of only a few millimeters in height and in diameter were tested and led to a laser emission around 1064 nm, characterized by a very low pump power threshold of ?5 mW, but with a limited slope efficiency (?4.6%). The spectral characteristics were also measured and some anisotropic enlargement of the laser emission band toward longer wavelength was noticed with increasing the pump power. Finally, monomodal or multimodal laser emission was evidenced, depending again on the pump power.

  15. White light generation in Dy(3+)-doped oxyfluoride glass and transparent glass-ceramics containing CaF2 nanocrystals.

    PubMed

    Babu, P; Jang, Kyoung Hyuk; Rao, Ch Srinivasa; Shi, Liang; Jayasankar, C K; Lavín, Víctor; Seo, Hyo Jin

    2011-01-31

    The radiative emission properties of the Dy3+ ions in an oxyfluoride glass and glass-ceramics have been studied for the generation of white light. The x-ray diffraction pattern of the glass-ceramics shows the formation of CaF2 fluorite-type nanocrystals in the glass matrix after a suitable thermal treatment of the precursor glass, whereas time-resolved optical measurements show the incorporation of the Dy3+ ions in the CaF2 nanocrystals. Intense white light has been observed when the samples are excited with 451 nm laser light. From the visible emission spectra, yellow to blue intensity ratios and the chromaticity color coordinates have been determined. All the color coordinates are found to lie in the white light region of the chromaticity color diagram. PMID:21368998

  16. 575 nm laser oscillation in Dy3+-doped waterproof fluoro-aluminate glass fiber pumped by violet GaN laser diodes

    NASA Astrophysics Data System (ADS)

    Fujimoto, Yasushi; Ishii, Osamu; Yamazaki, Masaaki

    2011-02-01

    We successfully drew a low-loss Dy-doped optical fiber (0.3dB/m at 532nm) of a waterproof fluoro-aluminate glass system and demonstrated yellow laser oscillation in the Dy3+-doped fluoride fiber pumped by a 398.8-nm GaN laser diode. The maximum output power was 10.3 mW and the slope efficiency was 17.1% at 575 nm. Since the fluoro-aluminate- glass system has a remarkable water resistance advantage compared to ZBLAN glass, Dy-doped fluoro-aluminate glass fiber is expected to contribute to making a solid-state yellow fiber laser with high chemical durability without a frequency doubling technique.

  17. Investigation of mid-infrared emission characteristics and energy transfer dynamics in Er3+ doped oxyfluoride tellurite glass

    PubMed Central

    Chen, Fangze; Wei, Tao; Jing, Xufeng; Tian, Ying; Zhang, Junjie; Xu, Shiqing

    2015-01-01

    Er3+ doped oxyfluoride tellurite glasses have been prepared. Three Judd-Ofelt parameters ?t (t?=?2, 4, 6) and radiative properties are calculated for prepared glasses. Emission characteristics are analyzed and it is found that prepared glasses possess larger calculated predicted spontaneous transition probability (39.97?s?1), emission cross section ?em (10.18?×?10?21?cm2) and ?em?×???eff (945.32?×?10?28?cm3), corresponding to the 2.7??m emission of Er3+: 4I11/2??4I13/2 transition. The results suggest that the prepared glasses might be appropriate optical material for mid-infrared laser application. Moreover, rate equation analysis which is rarely used in bulk glass has been carried out to explain the relationship between emission intensity and Er3+ concentration. The calculation results show that with the increment of Er3+ concentration, the energy transfer up-conversion rate of 4I13/2 state increases while the rate of 4I11/2 state reduces, resulting in the change of 2.7??m emission. PMID:26032900

  18. Adjustable up-conversion luminescence color in rare earth co-doped transparent oxyfluoride nano-glass-ceramics.

    PubMed

    Song, Zhiguo; Zhou, Dacheng; Qiu, Jianbei

    2010-03-01

    Transparent oxyfluoride nano-glass-ceramics with highly efficient up-conversion and adjustable color luminescence were developed in the 28SiO2 x 17Al2O3 28PbF2 x 22CdF2 x 0.1NdF3 x xYbF3 x yHoF3 zTmF3 x (4.9 - x - y - z)GdF3 composition, in mol%. X-ray diffraction and transmission electron microscopy measurements revealed that heat treatments of the oxyfluoride glasses cause the homogeneous precipitation of rare-earth ions co-doped fluorite-type Pb(x)Cd1-xF2 nanocrystals of about 10 nm in diameter in the glass matrix. Under single 808 nm laser excitation, intense red, green and blue up-conversion luminescences were simultaneously observed in these transparent nano-glass-ceramics owing to the successive energy transfer from Nd3+ ions to Ho3+ and Tm3+ via Yb3+ ions. Various colors of luminescence, including bright perfect white light, can be tuned by adjusting the concentrations of the Tm3+ ions in the material. A possible energy transfer process and up-conversion luminescence mechanism in the nano-glass-ceramics are proposed and discussed. PMID:20355610

  19. Copper-doped borosilicate bioactive glass scaffolds with improved angiogenic and osteogenic capacity for repairing osseous defects.

    PubMed

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

    2015-03-01

    There is growing interest in the use of synthetic biomaterials to deliver inorganic ions that are known to stimulate angiogenesis and osteogenesis in vivo. In the present study, we investigated the effects of varying amounts of copper in a bioactive glass on the response of human bone marrow-derived mesenchymal stem cells (hBMSCs) in vitro and on blood vessel formation and bone regeneration in rat calvarial defects in vivo. Porous scaffolds of a borosilicate bioactive glass (composition 6Na2O, 8K2O, 8MgO, 22CaO, 36B2O3, 18SiO2, 2P2O5, mol.%) doped with 0.5, 1.0 and 3.0wt.% CuO were created using a foam replication method. When immersed in simulated body fluid, the scaffolds released Cu ions into the medium and converted to hydroxyapatite. At the concentrations used, the Cu in the glass was not toxic to the hBMSCs cultured on the scaffolds in vitro. The alkaline phosphatase activity of the hBMSCs and the expression levels of angiogenic-related genes (vascular endothelial growth factor and basic fibroblast growth factor) and osteogenic-related genes (runt-related transcription factor 2, bone morphogenetic protein-2 and osteopontin) increased significantly with increasing amount of Cu in the glass. When implanted in rat calvarial defects in vivo, the scaffolds (3wt.% CuO) significantly enhanced both blood vessel formation and bone regeneration in the defects at 8weeks post-implantation. These results show that doping bioactive glass implants with Cu is a promising approach for enhancing angiogenesis and osteogenesis in the healing of osseous defects. PMID:25534470

  20. [Effect of bivalent alkaline earth fluorides introduction on thermal stability and spectroscopic properties of Er3+/Tm3+ /Yb3+ co-doped oxyfluorogermanate glasses].

    PubMed

    Hu, Yue-bo; Zhang, Xin-na; Zhou, Da-li; Jiao, Qing; Wang, Rong-fei; Huang, Jin-feng; Long, Xiao-bo; Qiu, Jian-bei

    2012-01-01

    Transparent Er3+/Tm3+ /Yb3+ co-doped oxyfluorogermanate glasses alone containing MgF2, CaF2, SrF2 or BaF2 and nano-glass-ceramics only containing BaF2 were prepared. The thermal stabilities and the up-conversion emission properties of the samples were investigated. Analyses of absorbance spectra reveal that the UV cutoff band moves slightly to shortwave band with the doping bivalent cation mass increasing. The results show that the emission color can be adjusted by changing the alkaline earth cation species in the glass matrixes, especially as Mg2+ is concerned, and the emission intensity can increase notably by heating the glass containing alkaline-earth fluoride into glass ceramic containing alkaline-earth fluoride nanocrystals or increasing the content of bivalent alkaline earth fluorides. PMID:22497127

  1. Enhanced NIR downconversion luminescence by precipitating nano Ca5(PO4)3F crystals in Eu2+-Yb3+ co-doped glass.

    PubMed

    Li, Chen; Song, Zhiguo; Li, Yongjin; Lou, Kai; Qiu, Jianbei; Yang, Zhengwen; Yin, Zhaoyi; Wang, Xue; Wang, Qi; Wan, Ronghua

    2013-10-01

    Eu(2+)-Yb(3+) co-doped transparent glass-ceramic containing nano-Ca5(PO4)3F (FAP) was prepared in reducing atmosphere. XRD and TEM analysis indicated that nano-FAP about 40 nm precipitated homogeneously in glass matrix after heat treatment. Confirmed by spectroscopy measurements, the crystal-like absorption and emission of Eu(2+) indicated the partition of Eu(2+) into FAP nanocrystals in glass ceramic. NIR emission due to the transition (2)F5/2?(2)F7/2 of Yb(3+) ions (about 980-1100 nm) was observed from glasses under ultraviolet excitation, ascribed to downconversion from Eu(2+) to Yb(3+), which can be enhanced by precipitating nano-FAP crystals. The results indicated that Eu(2+)-Yb(3+) co-doped glass-ceramic embedding with nano-FAP is a promising candidate as downconversion materials for enhancing conversion efficiency of solar cells. PMID:23816484

  2. Synthesis and properties of ZnTe and Eu{sup 3+} ion co-doped glass nanocomposites

    SciTech Connect

    Rahaman Molla, Atiar; Tarafder, Anal; Dey, Chirantan; Karmakar, Basudeb

    2014-10-28

    In this study, ZnTe (II-VI) semiconductor and Eu{sup +3}-ion co-doped borosilicate glass has been prepared in the SiO{sub 2}-K{sub 2}O-CaO-BaO-B{sub 2}O{sub 3} glass system followed by controlled heat-treatment to produce glass nanocomposites. Glass transition temperature and crystallization peak temperature have been evaluated using DSC analysis. Dilatometric studies were carried out to evaluate thermal expansion co-efficient, glass transition temperature, and dilatometric softening temperature and found to be 10.7 × 10{sup ?6}/K, 580°?C and 628°?C, respectively. TEM micrographs demonstrate formation of nano sized crystallites of less than 50?nm. The ZnTe crystal formation also established through selected area electron diffraction (SAED) analysis and high resolution images obtained through TEM studies. With increasing heat treatment time, optical transmission cut-off wavelength (?{sub cut-off}) shifted towards higher wavelength. Excitation spectra were recorded by monitoring emission at 613?nm corresponding to the {sup 5}D{sub 0} ? {sup 7}F{sub 2} transition. An intense 394?nm excitation band corresponding to the {sup 7}F{sub 0} ? {sup 5}L{sub 6} transition was observed. Emission spectra were then recorded by exciting the glass samples at 394?nm. When the glass is heat-treated for 30 min at 610°?C, a 6-fold increase in the intensity of the red emission at 612?nm has been observed, which is attributed to the segregation of Eu{sup 3+} ions into the low phonon energy ZnTe crystallites and as the size of the nanocrystals is smaller than the size of the exciton, quantum confinement effect is visible. Further increase in heat-treatment duration led to decrease in luminescence intensity due to the growth of larger size crystals. {sup 5}D{sub 1} ? {sup 7}F{sub 0} transition is visible only in the samples heat-treated for 30 min and 1 h, which is a characteristic of presence of Eu{sup 3+} ions in the low phonon energy ZnTe crystal sites. The micro hardness of the precursor glass and glass nanocomposites was evaluated; base glass shows hardness of 6.7 GPa and hardness of heat-treated glass nanocomposites has been found to decrease with increase in heat-treatment duration (5.5-5.3 GPa). However, mechanical properties are found to be suitable for device applications.

  3. Absorption and photoluminescence properties of Er-doped and Er/Yb codoped soda-silicate laser glasses

    SciTech Connect

    Li, S.F.; Zhang, Q.Y.; Lee, Y.P.

    2004-11-01

    Er-doped and Er/Yb codoped soda-silicate laser glasses with various concentrations of Er and Yb were fabricated. The absorption and the photoluminescence (PL) spectra were measured and analyzed. For the Er- doped soda-slilicate glasses, the optimum Er concentration for the PL intensity at 1536 nm turns out to be 0.5 at. %, and the full width at half maximum (FWHM) of PL spectrum increases from 18 to 26 nm, with the increase of the concentration from 0.1 to 0.8 at. %. The PL intensity of Er/Yb codoped soda-silicate glasses with an Er concentration of 0.5 at. % is enhanced approximately by four times, and the optimum Yb concentration for the PL intensity at 1536 nm is analyzed to be 3.0 at. %. The PL spectrum becomes broader with increasing the Yb concentration, up to a FWHM of 80 nm at 6.0 at. %. Yb. The relation between the absorption and PL spectra, together with the mechanism of PL broadening, has also been addressed.

  4. Pr3+-doped heavy metal germanium tellurite glasses for irradiative light source in minimally invasive photodynamic therapy surgery.

    PubMed

    Yang, J; Chen, B J; Pun, E Y B; Zhai, B; Lin, H

    2013-01-14

    Pr3+-doped medium-low phonon energy heavy metal germanium tellurite (NZPGT) glasses have been fabricated and the intense multi-peak red fluorescence emissions of Pr3+ are exhibited. Judd-Ofelt parameters ?2 = 3.14 × 10(-20)cm(2), ?4 = 10.67 × 10(-20)cm(2) and ?6 = 3.95 × 10(-20)cm(2) indicate a high asymmetrical and covalent environment in the optical glasses. The spontaneous emission probabilities A(ij) corresponding to the 1D2?3H4, 3P0?3H6, and 3P0?3F2 transitions are derived to be 1859.6, 6270.1 and 17276.3s(-1), respectively, and the relevant stimulated emission cross-sections ?(em) are 5.20 × 10(-21), 14.14 × 10(-21) and 126.77 × 10(-21)cm(2), confirming that the effectiveness of the red luminescence in Pr3+-doped NZPGT glasses. Under the commercial blue LED excitation, the radiant flux and the quantum yield for the red fluorescence of Pr3+ are solved to be 219?W and 11.80%, respectively. 85.24% photons of the fluorescence in the visible region are demonstrated to be located in 600-720nm wavelength range, which matches the excitation band of the most photosensitizers (PS), holding great promise for photodynamic therapy (PDT) treatment and clinical trials. PMID:23388997

  5. Luminescence studies on Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses for WLED applications

    NASA Astrophysics Data System (ADS)

    Vijayakumar, M.; Uma, V.; Arunkumar, S.; Marimuthu, K.

    2015-06-01

    Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses have been prepared and optically characterized using absorption, luminescence and decay measurements. The Nephelauxetic ratios (?), Bonding parameters (?) and Judd-Ofelt (JO) intensity parameters ?? (? = 2, 4 and 6) were calculated to study the nature of the environment around the RE3+ ions in the prepared glasses. The yellow to blue (Y/B) intensity ratio and the chromaticity color coordinates were calculated from the luminescence measurements. The lifetimes of the 4F9/2 excited level were measured using decay curves and is found to decrease in the Dy3+:Eu3+ co-doped glass due to the occurrence of resonant energy transfer between Dy3+-Eu3+ ions and the non-exponential decay rates have been fitted with Inokuti-Hirayama (IH) model. The decay curves are well fitted for S= 6 suggesting that the interaction between active ions for the energy transfer is of dipole-dipole nature.

  6. Energy transfer characteristics of silicate glass doped with Er3+, Tm3+, and Ho3+ for ˜2 ?m emission

    NASA Astrophysics Data System (ADS)

    Li, Ming; Liu, Xueqiang; Guo, Yanyan; Hu, Lili; Zhang, Junjie

    2013-12-01

    A Er3+/Tm3+/Ho3+ tri-doped silicate glass with good thermal stability is prepared by melt-quenching method. Efficient ˜2 ?m emission is observed under 808 nm laser excitation. It is found that the 2.0 ?m emission of Ho3+ can be enhanced under the excitation at 808 nm by incorporating Er3+ and Tm3+. Based on the measurement of absorption spectra, the Judd-Ofelt intensity parameters, radiation emission probability, and branching ratio are calculated to evaluate the spectroscopic properties simultaneously. The maximum value of emission cross section of Ho3+ is 3.54 × 10-21 cm2 at 2008 nm. Additionally, the phonon assistance and the micro-parameters in the energy transfer process are quantitatively analyzed by using Dexter model. The energy transfer coefficient from Tm3+ to Ho3+ can reach as high as 21.44 × 10-40 cm6/s, respectively. The emission property together with good thermal property indicates that Er3+/Tm3+/Ho3+ tri-doped silicate glass is a potential kind of laser glass for efficient 2 ?m laser.

  7. Yb-doped silica-based laser fibers: correlation of photodarkening kinetics and related optical properties with the glass composition

    NASA Astrophysics Data System (ADS)

    Kirchhof, J.; Unger, S.; Jetschke, S.; Schwuchow, A.; Leich, M.; Reichel, V.

    2009-02-01

    In the last years, photodarkening in ytterbium doped silica based laser fibers turned out to be a critical factor for high power laser action. Several investigations have been carried out in order to characterize the time dependent increase of the fiber loss and to understand and model the complex optical phenomenon. Despite of progress in this field, there is still a lack of data concerning the detailed influence of fiber composition and preparation process parameters as well as concerning the role of atomic defects in the core glass. Here we report on investigations about the photodarkening in dependence on the glass composition of the fiber laser core. By MCVD, fibers with different codopants (additional to the active ytterbium doping) have been prepared in a well-defined manner, regarding process parameters and glass composition, and comprehensively characterized. In addition to the photodarkening measurements, further optical properties have been measured on the fibers and fiber performs, which are related to the photodarkening effect: intensity and spectral behaviour of the Yb3+ absorption and emission in the NIR, cooperative visible fluorescence, UV absorption and UV excited visible emission. The concentration of codopants which are commonly used for active and passive lightguide fibers (aluminium, germanium, phosphorus) was systematically varied and correlated with the optical properties.

  8. Visible to infrared energy conversion in Pr3+-Yb3+ co-doped fluoroindate glasses

    NASA Astrophysics Data System (ADS)

    Borrero-González, L. J.; Galleani, G.; Manzani, D.; Nunes, L. A. O.; Ribeiro, S. J. L.

    2013-10-01

    Processes involving visible to infrared energy conversion are presented for Pr3+-Yb3+ co-doped fluoroindate glasses. The emission in the visible and infrared regions, the luminescence decay time of the Pr3+:3P0 ? 3H4 (482 nm), Pr3+:1D2 ? 3H6 (800 nm), Yb3+:2F5/2 ? 2F7/2 (1044 nm) transitions and the photoluminescence excitation spectra were measured in Pr3+ samples and in Pr3+-Yb3+ samples as a function of the Yb3+ concentration. In addition, energy transfer efficiencies were estimated from Pr3+:3P0 and Pr3+:1D2 levels to Yb3+:2F7/2 level. Down-Conversion (DC) emission is observed due to a combination of two different processes: 1-a one-step cross relaxation (Pr3+:3P0 ? 1G4; Yb3+:2F7/2 ? 2F5/2) resulting in one photon emitted by Pr3+ (1G4 ? 3H5) and one photon emitted by Yb3+ (2F7/2 ? 2F5/2); 2-a resonant two-step first order energy transfer, where the first part of energy is transferred to Yb3+ neighbor through cross relaxation (Pr3+:3P0 ? 1G4; Yb3+:2F7/2 ? 2F5/2) followed by a second energy transfer step (Pr3+:1G4 ? 3H4; Yb3+:2F7/2 ? 2F5/2). A third process leading to one IR photon emission to each visible photon absorbed involves cross relaxation energy transfer (Pr3+:1D2 ? 3F4; Yb3+:2F7/2 ? 2F5/2).

  9. Three-dimensional endothelial cell morphogenesis under controlled ion release from copper-doped phosphate glass.

    PubMed

    Stähli, Christoph; James-Bhasin, Mark; Nazhat, Showan N

    2015-02-28

    Copper ions represent a promising angiogenic agent but are associated with cytotoxicity at elevated concentrations. Phosphate-based glasses (PGs) exhibit adjustable dissolution properties and allow for controlled ion release. This study examined the formation of capillary-like networks by SVEC4-10 endothelial cells (ECs) seeded in a three-dimensional (3D) type I collagen hydrogel matrix mixed with PG particles of the formulation 50P2O5-30CaO-(20-x)Na2O-xCuO (x=0 and 10 mol%). Copper and total phosphorus release decreased over time and was more sustained in the case of 10% CuO PG. Moreover, increasing the concentration of 10% CuO PG in collagen substantially delayed dissolution along with preferential release of copper. A 3D morphometric characterization method based on confocal laser scanning microscopy image stacks was developed in order to quantify EC network length, connectivity and branching. Network length was initially reduced in a concentration-dependent fashion by 10% CuO PG and, to a lesser extent, by 0% CuO PG, but reached values identical to the non-PG control by day 5 in culture. This reduction was attributed to a PG-mediated decrease in cell metabolic activity while cell proliferation as well as network connectivity and branching were independent of PG content. Gene expression of matrix metalloproteinases (MMP)-1 and -2 was up-regulated by PGs, indicating that MMPs did not play a critical role in network growth. The relationship between ion release and EC morphogenesis in 3D provided in this study is expected to contribute to an ultimately successful pro-angiogenic application of CuO-doped PGs. PMID:25575746

  10. Chromium doped nano-phase separated yttria-alumina-silica glass based optical fiber preform: fabrication and characterization

    NASA Astrophysics Data System (ADS)

    Dutta, Debjit; Dhar, Anirban; Das, Shyamal; Bysakh, Sandip; Kir'yanov, Alexandar; Paul, Mukul Chandra

    2015-06-01

    Transition metal (TM) doping in silica core optical fiber is one of the research area which has been studied for long time and Chromium (Cr) doping specially attracts a lot of research interest due to their broad emission band covering U, C and L band with many potential application such as saturable absorber or broadband amplifier etc. This paper present fabrication of Cr doped nano-phase separated silica fiber within yttria-alumina-silica core glass through conventional Modified Chemical Vapor Deposition (MCVD) process coupled with solution doping technique along with different material and optical characterization. For the first time scanning electron microscope (SEM) / energy dispersive X-ray (EDX) analysis of porous soot sample and final preform has been utilized to investigate incorporation mechanism of Crions with special emphasis on Cr-species evaporation at different stages of fabrication. We also report that optimized annealing condition of our fabricated preform exhibited enhanced fluorescence emission and a broad band within 550- 800 nm wavelength region under pumping at 532 nm wavelength due to nano-phase restructuration.

  11. Cr-doped scandium borate laser

    DOEpatents

    Chai, Bruce H. (Bridgewater, NJ); Lai, Shui T. (Florham Park, NJ); Long, Margaret N. (Landing, NJ)

    1989-01-01

    A broadly wavelength-tunable laser is provided which comprises as the laser medium a single crystal of MBO.sub.3 :Cr.sup.3+, where M is selected from the group of Sc, In and Lu. The laser may be operated over a broad temperature range from cryogenic temperatures to elevated temperatures. Emission is in a spectral range from red to infrared, and the laser is useful in the fields of defense, communications, isotope separation, photochemistry, etc.

  12. Surface silver-doping of biocompatible glasses to induce antibacterial properties. Part II: Plasma sprayed glass-coatings.

    PubMed

    Miola, M; Ferraris, S; Di Nunzio, S; Robotti, P F; Bianchi, G; Fucale, G; Maina, G; Cannas, M; Gatti, S; Massé, A; Vitale Brovarone, C; Verné, E

    2009-03-01

    A 57% SiO(2), 3% Al(2)O(3), 34% CaO and 6% Na(2)O glass (SCNA) has been produced in form of powders and deposited by plasma spray on titanium alloy and stainless steel substrates. The obtained coatings have been subjected to a patented ion-exchange treatment to introduce silver ions in the surface inducing an antibacterial behavior. Silver surface-enriched samples have been characterized by means of X-ray diffraction, SEM observation, EDS analysis, in vitro bioactivity tests, leaching tests by GFAAS (graphite furnace atomic adsorption spectroscopy) analyses, cells adhesion and proliferation, and antibacterial tests using Staphylococcus Aureus strain. In vitro tests results showed that the modified samples acquired an antimicrobial action against tested bacteria maintaining unaffected the biocompatibility of the glass. Furthermore the ion-exchange treatment can be successfully applied to glass-coated samples without affecting the properties of the coatings; the simplicity and reproducibility of the method make it suitable for glass or glass-ceramic coatings of different composition in order to produce coated devices for bone healing and/or prostheses, able to reduce bacterial colonization and infections risks. PMID:18987953

  13. Spatial self-phase modulation in the H2TPP(OH)4 doped in Boric Acid Glass

    E-print Network

    Allam, Srinivasa Rao; Venkatramaiah, N; Venkatesan, R; Sharan, Alok

    2015-01-01

    Self-diffraction rings or spatial self-phase modulation (SSPM) was observed in tetra-phenyl porphyrin derivative 5,10,15,20 - meso-tetrakis (4-hydroxyphenyl) porphyrin (H2TPP(OH)4) doped in boric acid glass (BAG) at 671 nm excitation wave-length lying within the absorption band of sample with TEM00 mode profile. Intensity modulated Z-scan was performed on these systems to study the thermal diffusion and to estimate the thermo-optic coefficients. The results obtained from self-diffraction rings experiment and modulated Z-scan are compared and analyzed for different concentration.

  14. Three-photon near-infrared quantum cutting in Tm{sup 3+}-doped transparent oxyfluoride glass ceramics

    SciTech Connect

    Yu, D. C.; Zhang, J. P.; Chen, Q. J.; Zhang, W. J.; Yang, Z. M.; Zhang, Q. Y.

    2012-10-22

    Efficient three-step sequential three-photon near-infrared (NIR) quantum cutting in Tm{sup 3+}-doped transparent oxyfluoride glass ceramics has been demonstrated, where an absorbed blue photon could be cut into three NIR photons at 1190, 1460, and 1800 nm with quantum yield greater than unity. On the basis of static and dynamic photoemission, monitored excitation, and time-resolved fluorescence spectra, we investigate in detail the underlying optoelectronic mechanism. Further development of an efficient triply-cutting material might open up a path towards ultra-efficient photonic devices, which enables more photons emitted than absorbed in the excitation process.

  15. Absorption, fluorescence and second harmonic generation in Cr3+-doped BiB3O6 glasses

    NASA Astrophysics Data System (ADS)

    Kuznik, W.; Fuks-Janczarek, I.; Wojciechowski, A.; Kityk, I. V.; Kiisk, V.; Majchrowski, A.; Jaroszewicz, L. R.; Brik, M. G.; Nagy, G. U. L.

    2015-06-01

    Synthesis, spectral properties and photoinduced nonlinear optical effects of chromium-doped BiB3O6 glass are studied in the present paper. Absorption, excitation and time resolved luminescence spectra are presented and luminescence decay behavior is discussed. Detailed analysis of the obtained spectra (assignment of the most prominent spectral features in terms of the corresponding Cr3+ energy levels, crystal field strength Dq, Racah parameters B and C) was performed. A weak photostimulated second harmonic generation signal was found to increase drastically due to poling by proton implantation in the investigated sample.

  16. Sustained phase separation and spin glass in Co-doped KxFe2 -ySe2 single crystals

    NASA Astrophysics Data System (ADS)

    Ryu, Hyejin; Wang, Kefeng; Opacic, M.; Lazarevic, N.; Warren, J. B.; Popovic, Z. V.; Bozin, Emil S.; Petrovic, C.

    2015-11-01

    We present Co substitution effects in KxFe2 -y -zCozSe2 (0.06 ?z ?1.73 ) single-crystal alloys. By 3.5% of Co doping superconductivity is suppressed, whereas phase separation of semiconducting K2Fe4Se5 and superconducting/metallic KxFe2Se2 is still present. We show that the arrangement and distribution of the superconducting phase (stripe phase) are connected with the arrangement of K, Fe, and Co atoms. Semiconducting spin glass is found in proximity to the superconducting state, persisting for large Co concentrations. At high Co concentrations a ferromagnetic metallic state emerges above the spin glass. This is coincident with changes of the unit cell and arrangement and connectivity of the stripe conducting phase.

  17. The effect of La2O3 in Tm3+-doped germanate-tellurite glasses for ~2??m emission

    PubMed Central

    Peng, Ya-Pei; Yuan, Xinqiang; Zhang, Junjie; Zhang, Long

    2014-01-01

    A germanate-tellurite glass (GeO2-TeO2-K2O-Nb2O5-La2O3) with thulium doping has been investigated for application as a laser material around 2.0??m regions. Under the 808?nm laser diode pumped, intense 1.8??m emission is obtained. Based on the absorption spectra, radiative properties are predicted using Judd-Ofelt theory. The maximum value of emission cross-section of Tm3+ around 1.8??m can reach 1.46 × 10?20?cm2, which indicated that the germanate-tellurite glass may provide high gain as a good medium for efficient 1.8??m laser system. PMID:24918516

  18. Magnetocaloric effect in heavy rare-earth elements doped Fe-based bulk metallic glasses with tunable Curie temperature

    SciTech Connect

    Li, Jiawei; Huo, Juntao; Chang, Chuntao E-mail: dujun@nimte.ac.cn; Du, Juan E-mail: dujun@nimte.ac.cn; Man, Qikui; Wang, Xinmin; Li, Run-Wei; Law, Jiayan

    2014-08-14

    The effects of heavy rare earth (RE) additions on the Curie temperature (T{sub C}) and magnetocaloric effect of the Fe-RE-B-Nb (RE?=?Gd, Dy and Ho) bulk metallic glasses were studied. The type of dopping RE element and its concentration can easily tune T{sub C} in a large temperature range of 120?K without significantly decreasing the magnetic entropy change (?S{sub M}) and refrigerant capacity (RC) of the alloys. The observed values of ?S{sub M} and RC of these alloys compare favorably with those of recently reported Fe-based metallic glasses with enhanced RC compared to Gd{sub 5}Ge{sub 1.9}Si{sub 2}Fe{sub 0.1}. The tunable T{sub C} and large glass-forming ability of these RE doped Fe-based bulk metallic glasses can be used in a wide temperature range with the final required shapes.

  19. Erbium-doped phosphate glass waveguide on silicon with 4.1 dB/cm gain Y. C. Yan,a)

    E-print Network

    Polman, Albert

    Erbium-doped phosphate glass waveguide on silicon with 4.1 dB/cm gain at 1.535 m Y. C. Yan,a) A. J Amsterdam, The Netherlands Received 28 July 1997; accepted for publication 17 September 1997 Erbium at low pump power. © 1997 American Institute of Physics. S0003-6951 97 02746-0 Erbium-doped planar

  20. Up-conversion emission tuning in triply-doped Yb3+/Tm3+/Er3+ novel fluoro-phosphate glass and glass-ceramics

    NASA Astrophysics Data System (ADS)

    Ledemi, Yannick; Trudel, Andrée.-Anne; Rivera, Victor A. G.; Messaddeq, Younes

    2014-03-01

    New Yb3+, Er3+ and Tm3+ triply doped fluoro-phosphate glasses belonging to the system NaPO3-YF3-BaF2-CaF2 have been prepared by the classical melt-casting technique. Glasses containing up to 10 wt.% of rare-earth ions fluorides have been obtained and characterized by using differential scanning calorimetry (DSC), UV-visible-near-infrared spectroscopy and up-conversion emission spectroscopy under excitation with a 975 nm laser diode. Transparent and optically homogeneous glass-ceramics have been reproducibly obtained by appropriate heat treatment in view to manage the red, green and blue emissions upon 975 nm laser excitation. According to the applied thermal heat-treatment, a large enhancement of intensity of the up-conversion emission - from 10 to 160 times higher - has been achieved in the glassceramics compared to that of glasses, suggesting incorporation of the rare-earth ions into the crystalline phase. Furthermore, a large range of color rendering has been observed in these materials by controlling the laser excitation power and material crystallization rate. Time-resolved luminescence experiments as well as X-ray diffractometry and scanning electron microscopy techniques have been employed in order to understand and correlate the multicolor emission changes to the crystallization behavior of this material. A progressive phase transformation of the fluorite-type CaF2-based nanocrystals initially generated was observed along with increasing heat-treatment time, thus modifying the rare earth ions spectroscopic features.

  1. Spectroscopic characterization and optical waveguide fabrication in Ce 3+, Tb 3+ and Ce 3+/Tb 3+ doped zinc-sodium-aluminosilicate glasses

    NASA Astrophysics Data System (ADS)

    Caldiño, U.; Speghini, A.; Álvarez, E.; Berneschi, S.; Bettinelli, M.; Brenci, M.; Righini, G. C.

    2011-10-01

    A spectroscopy investigation of Ce 3+ and Tb 3+ ions in sodium-zinc-aluminosilicate glasses is performed using the photoluminescence technique. Blue-white light, with x = 0.24 and y = 0.24 CIE chromaticity coordinates, is obtained for the Tb 3+ singly-doped glass excited at 351 nm. When the sodium-zinc-aluminosilicate glass is co-doped with Ce 3+ and Tb 3+ a non-radiative energy transfer from Ce 3+ to Tb 3+ ions is observed upon 320 nm excitation. From an analysis of the cerium emission decay curve, the Ce 3+ ? Tb 3+ energy transfer microscopic parameter and efficiency are obtained. Different concentrations of Ce 3+ and Tb 3+ ions in the glass host gives rise to blue and blue-green emissions, with different CIE coordinates. Optical waveguides were produced in the samples by Ag +-Na + ion-exchange, and their characterization is presented.

  2. Chemistry of titanium incorporation in silica glass of optical preform for making of Ti doped optical fibre by the MCVD process

    NASA Astrophysics Data System (ADS)

    Paul, M. C.; Sen, R.; Bhadra, S. K.; Dasgupta, K.

    2008-06-01

    A detailed theoretical and experimental investigation of incorporation of titanium dioxide into a silica glass preform for making of Ti doped optical fibre by the modified chemical vapour deposition process is presented. Such detailed investigation about incorporation of titanium into a silica glass was done with emphasis on its importance in increasing the refractive index of silica glass optical fibre for use as a radiation sensor in fibre optic dosimeters. Selection of the proper proportions of the supplied reagents TiCl4, O2 and He in the inlet gas mixture was found to be very much important in order to achieve a desired profile of Ti doped fibre made by the MCVD process. The chemistry of titanium incorporation in silica glass has been thoroughly discussed with regard to thermodynamic data by selection of the proper proportions of the precursor reagents TiCl4, O2 and He in the inlet gas mixture and studied the effect of deposition temperature.

  3. Efficient 2.7 ?m emission and energy transfer mechanism in Er3+ doped Y2O3 and Nb2O5 modified germanate glasses

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Chen, Fangze; Tian, Ying; Xu, Shiqing

    2014-01-01

    In this paper, Er3+ doped Y2O3 and Nb2O5 modified germanate glasses possessing good thermal stability are reported. On the basis of absorption spectra and Judd-Ofelt theory, a detailed investigation of Judd-Ofelt intensity parameters (?2,4,6) and radiative properties is carried out. Moreover, emission cross section at 2.7 ?m is calculated based on Füchtbauer-Ladenburg equation and compared with other Er3+ doped glass systems. A reasonable energy transfer mechanism is proposed. It is interesting that the emission cross section and radiative transition probability in 5 mol% Nb2O5 modified germanate glass are much larger than those with 5 mol% Y2O3. Results indicate that present germanate glasses along with excellent 2.7 ?m spectroscopic performance might have potential application for mid-infrared fiber laser.

  4. TiO2-doped phosphate glass microcarriers: A stable bioactive substrate for expansion of adherent mammalian cells

    PubMed Central

    Guedes, Joana C; Park, Jeong-Hui; Lakhkar, Nilay J; Kim, Hae-Won; Knowles, Jonathan C

    2013-01-01

    Scalable expansion of cells for regenerative cell therapy or to produce large quantities for high-throughput screening remains a challenge for bioprocess engineers. Laboratory scale cell expansion using t-flasks requires frequent passaging that exposes cells to many poorly defined bioprocess forces that can cause damage or alter their phenotype. Microcarriers offer a potential solution to scalable production, lending themselves to cell culture processes more akin to fermentation, removing the need for frequent passaging throughout the expansion period. One main problem with microcarrier expansion, however, is the difficulty in harvesting cells at the end of the process. Therefore, therapies that rely on cell delivery using biomaterial scaffolds could benefit from a microcarrier expansion system whereby the cells and microcarriers are transplanted together. In the current study, we used bioactive glass microcarriers doped with 5% TiO2 that display a controlled rate of degradation and conducted experiments to assess biocompatibility and growth of primary fibroblast cells as a model for cell therapy products. We found that the microcarriers are highly biocompatible and facilitate cell growth in a gradual controlled manner. Therefore, even without additional biofunctionalization methods, Ti-doped bioactive glass microcarriers offer potential as a cell expansion platform. PMID:22935537

  5. Undoped and Eu3+ doped In2O3 quantum-dots in transparent glass-ceramics.

    PubMed

    del-Castillo, J; Yanes, A C; Méndez-Ramos, J; Rodríguez, V D

    2009-08-01

    Nano-structured glass-ceramics comprising In2O3 nanocrystals (quantum dots) in a silica glassy matrix have been synthesized for the first time to our knowledge, by thermal treatment of sol-gel precursor glasses with different concentrations of In2O3. Undoped and Eu(3+)-doped samples have been obtained and characterized. By means of X-ray Diffraction and Transmission Electron Microscopy analysis, the precipitation of In2O3 cubic crystalline nanoparticles was confirmed. The mean radii of these nanocrystals, from 1 to 4 nm, are comparable to the exciton Bohr radius, corresponding to wide band-gap semiconductor quantum-dots. Under interband UV excitation of the nanocrystals, a broad visible emission is observed in the undoped samples. Meanwhile, the Eu(3+)-doped samples only show emission from these ions which are efficiently excited by energy transfer from the In2O3, nanocrystals. Selective excitation of the Eu3+ ions allow us to discern those remaining in the silica glassy matrix from the ones located in the interface SiO2-In2O3. PMID:19928158

  6. Broadband near-infrared emission from Tm{sup 3+}/Er{sup 3+} co-doped nanostructured glass ceramics

    SciTech Connect

    Chen Daqin; Wang Yuansheng; Bao Feng; Yu Yunlong

    2007-06-01

    Transparent SiO{sub 2}-Al{sub 2}O{sub 3}-NaF-YF{sub 3} glass ceramics co-doped with Er{sup 3+} and Tm{sup 3+} were prepared by melt quenching and subsequent heating. X-ray diffraction and transmission electron microscopy experiments revealed that {beta}-YF{sub 3} nanocrystals incorporated with Er{sup 3+} and Tm{sup 3+} 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 Tm{sup 3+} emissions around 1472 nm ({sup 3}H{sub 4}{yields}{sup 3}F{sub 4}) and 1626 nm ({sup 3}F{sub 4}{yields}{sup 3}H{sub 6}), and Er{sup 3+} emission around 1543 nm ({sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2}), 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% Er{sup 3+} and 0.8 mol% Tm{sup 3+} co-doped sample. The energy transfers between Er{sup 3+} and Tm{sup 3+} were proposed to play an important role in tailoring the emission bandwidth of the sample.

  7. 2.7 ?m emission properties of Er3+ doped tungsten-tellurite glass sensitized by Yb3+ ions.

    PubMed

    Guo, Yanyan; Ma, Yaoyao; Huang, Feifei; Peng, Yapei; Zhang, Liyan; Zhang, Junjie

    2013-07-01

    With a 980 nm laser diode (LD) pumped, the sensitized effect of Yb(3+) ions on 2.7 ?m emission properties and energy transfer mechanism in Yb(3+)/Er(3+) co-doped tungsten-tellurite glass were investigated in present paper. Based on absorption spectra, Judd-Ofelt parameters and radiative transition probabilities were calculated and analyzed. The emission spectra were tested and the optimized concentration ratio of Yb(3+) to Er(3+) ions was found to be 3:0.5 with a largest calculated emission cross-section (6.05×10(-21) cm(2)) corresponding to Er(3+):(4)I11/2?(4)I13/2 transition. When the concentration ratio of Yb(3+) to Er(3+) ions was 4:0.5, 1.5 ?m and 2.7 ?m emission decreased while up-conversion increased. The decreased 1.5 ?m and 2.7 ?m emission were induced by the saturation of Er(3+):(4)I13/2 level. In brief, the advantageous spectroscopic characteristics indicated that Yb(3+)/Er(3+) co-doped tungsten-tellurite glass may be a promising candidate for application of 2.7 ?m emission. PMID:23624041

  8. 2.7 ?m emission properties of Er3+ doped tungsten-tellurite glass sensitized by Yb3+ ions

    NASA Astrophysics Data System (ADS)

    Guo, Yanyan; Ma, Yaoyao; Huang, Feifei; Peng, Yapei; Zhang, Liyan; Zhang, Junjie

    2013-07-01

    With a 980 nm laser diode (LD) pumped, the sensitized effect of Yb3+ ions on 2.7 ?m emission properties and energy transfer mechanism in Yb3+/Er3+ co-doped tungsten-tellurite glass were investigated in present paper. Based on absorption spectra, Judd-Ofelt parameters and radiative transition probabilities were calculated and analyzed. The emission spectra were tested and the optimized concentration ratio of Yb3+ to Er3+ ions was found to be 3:0.5 with a largest calculated emission cross-section (6.05 × 10-21 cm2) corresponding to Er3+:4I11/2 ? 4I13/2 transition. When the concentration ratio of Yb3+ to Er3+ ions was 4:0.5, 1.5 ?m and 2.7 ?m emission decreased while up-conversion increased. The decreased 1.5 ?m and 2.7 ?m emission were induced by the saturation of Er3+:4I13/2 level. In brief, the advantageous spectroscopic characteristics indicated that Yb3+/Er3+ co-doped tungsten-tellurite glass may be a promising candidate for application of 2.7 ?m emission.

  9. Growth, differentiation, and migration of osteoblasts on transparent Ni doped TiO2 thin films deposited on borosilicate glass.

    PubMed

    Dhayal, Marshal; Kapoor, Renu; Sistla, Pavana Goury; Kant, Chander; Pandey, Ravi Ranjan; Govind; Saini, Krishan Kumar; Pande, Gopal

    2012-05-01

    A simple and cost effective dip coating method was used to deposit thin films of amorphous (AM) or anatase (AN) titanium dioxide (TiO(2)) on borosilicate glass substrates, either with or without prior doping of TiO(2) with nickel (Ni) cations by a specially designed sol gel technique. The objective of the study was to compare the physicochemical and biological properties of these films and assess their use in orthopedic implants or for in vitro cell biological studies. Analytical techniques such as XRD and XPS, in combination with ATR-FTIR and SEM revealed that only AN films, prepared by controlled heating up to 450°C, irrespective of prior doping with Ni, contained significant crystalline structures of variable morphologies. This observation could be linked to the carbon and oxygen contents and the availability of functional groups in the films. Cell biological studies revealed that Ni doping of TiO(2) in both AM and AN films improved the adhesion, spreading, proliferation, differentiation, and migration of MC3T3 cells. Our studies provide a new approach to prepare optically transparent metal surfaces, with tunable physicochemical properties, which could be suitable for eliciting optimal osteoinductive cell responses and permit the detailed in vitro cell biological studies of osteoblasts. PMID:22337701

  10. The preparation of uranium-doped glass reference materials for environmental measurements

    NASA Astrophysics Data System (ADS)

    Raptis, K.; Ingelbrecht, C.; Wellum, R.; Alonso, A.; De Bolle, W.; Perrin, R.

    2002-03-01

    Seven different uranium glass powders containing 5 mass% uranium with 235U abundances from natural to highly enriched have been prepared for the IRMM support programme to the International Atomic Energy Agency (IAEA) and for the IRMM external NUSIMEP quality control programme (Nuclear Signatures Interlaboratory Measurement Evaluation Programme). The particles will be primarily used, blended with (inactive) matrix glass powder in various ratios to simulate environmental samples containing "hot" particles in order to assess the performance of various separation and measurement techniques. High-purity borosilicate glass was prepared by blending of powders, melting and grinding by ball milling and jet milling to a powder of about 12 ?m. A quantity of this glass was then blended with U 3O 8, melted and milled to powder. Laser diffraction measurements were made to ensure that the particle size distribution of the uranium glass matched that of the matrix glass in order to ensure homogeneous blending. The final yield was 30-40 g of each uranium glass and 1 kg of matrix glass. The glasses have been certified as reference materials for isotope abundances of uranium.

  11. Density and concentration fluctuations in F-doped SiO2 glass

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Saito, K.; Ikushima, A. J.

    2004-03-01

    The fictive temperature, Tf, and fluorine concentration dependences of structure fluctuation in SiO2 glass was investigated by small-angle x-ray scattering measurement. Regardless of F concentration, density fluctuation in SiO2 glass is proportional to Tf and depends on structural relaxation. Concentration fluctuation does not depend on Tf and is almost proportional to F concentration. And it implies that F is incorporated into the glass structure at temperatures considerably higher than the Tf on which glass structure freezes. Contributions of the density and concentration fluctuations to the structure fluctuation were estimated.

  12. Durability of glasses from the Hg-doped Integrated DWPF Melter System (IDMS) campaign

    SciTech Connect

    Jantzen, C.M.

    1992-08-30

    The Integrated DWPF Melter System (IDMS) for the vitrification of high-level radioactive wastes is designed and constructed to be a 1/9th scale prototype of the full scale Defense Waste Processing Facility (DWPF) melter. The IDMS facility is the first engineering scale melter system capable of processing mercury, and flowsheet levels of halides and noble metals. In order to determine the effects of mercury on the feed preparation process, the off-gas chemistry, glass melting behavior, and glass durability, a three-run mercury (Hg) campaign was conducted. The glasses produced during the Hg campaign were composed of Batch 1 sludge, simulated precipitate hydrolysis aqueous product (PHA) from the Precipitate Hydrolysis Experimental Facility (PHEF), and Frit 202. The glasses were produced using the DWPF process/product models for glass durability, viscosity, and liquidus. The durability model indicated that the glasses would all be more durable than the glass qualified in the DWPF Environmental Assessment (EA). The glass quality was verified by performing the Product Consistency Test (PCT) which was designed for glass durability testing in the DWPF.

  13. Thermoluminescence response of dysprosium doped strontium tetraborate glasses subjected to electron irradiations.

    PubMed

    Lim, Tou Ying; Wagiran, H; Hussin, R; Hashim, S

    2015-08-01

    The paper presents the thermoluminescence (TL) response of strontium tetraborate glass subjected to electron irradiations at various Dy2O3 concentrations ranging from 0.00 to 1.00mol%. All glass samples exhibited single broad peak with maximum peak temperature positioned at 170-215°C. The optimum TL response was found at Dy2O3 concentration 0.75mol%. This glass showed good linearity and higher sensitivity for 7MeV compared to 6MeV electrons. Analysis of kinetic parameters showed that the glasses demonstrate second order kinetic. PMID:25933405

  14. Structural characterization by x-ray methods of novel antimicrobial gallium-doped phosphate-based glasses

    SciTech Connect

    Pickup, D. M.; Moss, R. M.; Qiu, D.; Newport, R. J.; Valappil, S. P.; Knowles, J. C.; Smith, M. E.

    2009-02-14

    Antimicrobial gallium-doped phosphate-based glasses of general composition (P{sub 2}O{sub 5}){sub 0.45}(CaO){sub 0.16}(Na{sub 2}O){sub 0.39-x}(Ga{sub 2}O{sub 3}){sub x} (where x=0, 0.01, 0.03, and 0.05) have been studied using the advanced synchrotron-based techniques of Ga K-edge x-ray absorption spectroscopy and high-energy x-ray diffraction to provide a structural insight into their unique properties. The results show that the Ga{sup 3+} ions are octahedrally coordinated. Furthermore, substitution of Na{sub 2}O by Ga{sub 2}O{sub 3} strengthens the phosphate network structure because the presence of GaO{sub 6} octahedra inhibits the migration of the remaining Na{sup +} ions. The results are discussed in terms of the use of Na{sub 2}O-CaO-P{sub 2}O{sub 5} glasses as controlled-delivery devices for antimicrobial Ga{sup 3+} ions in biomedical applications. We are thereby able to relate the atomic-scale environment of the Ga{sup 3+} ions beneficially to the glass dissolution, and thus to their ability to disrupt bacterial cell activity by usurping the role of iron.

  15. Optical properties of bismuth-doped SiO2- or GeO2-based glass core optical fibers

    E-print Network

    Firstova, Elena G

    2015-01-01

    A detailed study of optical properties of bismuth-doped fibers based on SiO2 and GeO2 glasses containing no other dopants has been carried out. To provide important information about spectroscopic properties of IR bismuth-related active centers (BAC) the excitation-emission fluorescence spectra for a spectral region of 220-2000 nm have been measured. The obtained three-dimensional spectra have been presented for different host glass compositions: silicate, germanate, aluminosilicate and phosphosilicate. Energy-level configuration and main radiative transitions associated with BACs in GeO2 and SiO2 glasses have been revealed. Fluorescence lifetime analysis of the basic radiative transitions of BAC have been carried out. It has been shown that the energy-level schemes of BAC-Si and BAC-Ge (BAC associated with silicon and germanium, respectively) are similar, corresponding BAC-Ge energy levels lying 10-16% lower than those of BAC-Si. It has been determined that BAC-Si, BAC-Ge and BAC-Si, BAC-P can exist simultan...

  16. Picosecond nonradiative processes in neodymium-doped crystals and glasses: mechansim for the energy gap law

    SciTech Connect

    Bibeau, C.; Payne, S.A.

    1997-09-29

    We present measurements of the 4G7/2 emission lifetime for 26 Nd-doped materials. A model of nonradiative decay based on dipole-dipole energy transfer is developed and found to be supported by our data.

  17. Use of microgravity to improve the efficiency and power output of Nd-doped laser glasses

    NASA Technical Reports Server (NTRS)

    Ray, Chandra S.

    1992-01-01

    The objectives of this research are to: (1) obtain further evidence and understand the science for the reported improvement in chemical homogeneity in glasses prepared in microgravity; and (2) study the feasibility of improving the optical and fluorescence properties, particularly, the limit for Nd(+3) concentration quenching and threshold energy for laser action for laser glasses prepared in microgravity. Attention was directed to ground based investigation whose primary purpose was to determine the suitability and conditions for processing these laser glasses in space. This report describes that the scientific and technical information required for planning flight experiments for these glasses have been obtained, and the preparation for handling and analyzing post flight samples have also been taken. Instruments required for measuring the fluorescence properties of interest have been constructed. The optical and fluorescence properties for the glasses have been measured and made available for comparative property analysis.

  18. Optical doping of soda-lime-silicate glass with erbium by ion implantation E. Snoeks, G. N. van den Hoven, and A. Polman

    E-print Network

    Polman, Albert

    Optical doping of soda-lime-silicate glass with erbium by ion implantation E. Snoeks, G. N. van den, The Netherlands [Received 6 January 1993;acceptedfor publication 2 March 1993) Soda beenobservedat concentrationsof 0.1 at. %.l" In this work we investigate 500 keV Er-implanted soda

  19. A graphene-based mode-locked nano-engineered zirconia-yttria-aluminosilicate glass-based erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Paul, M. C.; Sobon, G.; Sotor, J.; Abramski, K. M.; Jagiello, J.; Kozinski, R.; Lipinska, L.; Pal, M.

    2013-03-01

    We demonstrate a simple, compact and low cost graphene-based mode-locked nano-engineered erbium-doped zirconia-yttria-aluminosilicate (ZYA-EDF) glass-based fiber laser. The fiber preform in a quaternary glass host of silica-zirconia-yttria-aluminum was made through the modified chemical vapor deposition (MCVD) process followed by the solution doping technique. The core glass is made of 0.40 mol% of Al2O3, 3.0 mol% of ZrO2 and 0.25 mol% of Er2O3, which give rise to a peak absorption of 30.0 dB m-1 at 978 nm and a fluorescence lifetime of 10.65 ms. Such a doping host provides the high concentration of erbium ions of 4500 ppm without any clustering. Such an active fiber was used as a gain medium for an ultra-fast femtosecond fiber laser, mode locked by a graphene oxide (GO) saturable absorber. This paper describes geometrical and optical characterization of the nano-engineered glass-based erbium-doped optical fiber (ZYA-EDF) as well as the performance of the mode-locked femtosecond laser based on the developed fiber. The all-anomalous cavity laser generated soliton pulses with 8.5 nm bandwidth, 50 MHz repetition frequency and nearly transform-limited 400 fs duration at 1561 nm center wavelength using a new class of EDF.

  20. Results of drip tests on sludge-based and actinide-doped glasses

    SciTech Connect

    Bates, J.K.; Buck, E.C.

    1994-04-01

    The reaction of three differs simulated nuclear waste glasses is being evaluated using a test method that slowly drips water onto a glass/metal assembly. The tests have been in progress for up to eight years and are being performed with as-cast and glass aged by reaction with water vapor. Results are presented for the cumulative release of Np, Pu, and Am as a function of time; also reported are the particulate species that have been detected suspended in solution. A significant difference is noted in the suspended species depending on the glass composition, and on whether the glass is aged. With as-cast glass, the radioactivity is associated with the suspended particles, while with the aged glass, the solution has a high initial anion content, and the transuranic elements appear to be dissolved in solution, since they pass through filters with small pore sizes. Examples are given of possible tests to evaluate the interaction between these test solutions and potential engineered barrier components.

  1. Soda-based glass fabricated from Thailand quartz sands doped with silver compound

    NASA Astrophysics Data System (ADS)

    Won-in, Krit; Dararutana, Pisutti

    2012-10-01

    Yellow colored glass which used for luxury art glass in ancient time was fabricated by the addition of silver compound into the molten glass. It was proved that it was actually silver nanoparticle technology. In this work, the SiO2-(Na2O,K2O)-CaO-B2O3-Al2O3-MgO glass system was prepared in the laboratory scale based on local quartz sands from Trat Province, eastern area of Thailand as the silica raw material. Various concentrations of silver nitrate were added. After the complete conventional melting process, the bubble-free yellow glasses were yielded. Physical and optical properties such as density, refractive index and optical absorption spectra were measured. Scanning electron microscope coupled with energy dispersive spectroscopy was carried out to study their morphology. The refractive indices and densities were increased as the increase of the silver contents. Electron micrographs showed the presence of silver nanoparticle in the glass matrix. UV-VIS spectra were in good agreement with that found from SEM measurements and corresponded with the universally accepted. It was also showed that the more brilliance on the surface of the glass products was obtained after firing with a gas torch.

  2. Chemical environment of rare earth ions in Ge28.125Ga6.25S65.625 glass-ceramics doped with Dy3+

    NASA Astrophysics Data System (ADS)

    Wang, Rongping; Yan, Kunlun; Zhang, Mingjie; Shen, Xiang; Dai, Shixun; Yang, Xinyu; Yang, Zhiyong; Yang, Anping; Zhang, Bin; Luther-Davies, Barry

    2015-10-01

    We have annealed Ge28.125Ga6.25S65.625 glasses doped with 0.5% Dy to create glass-ceramics in order to examine the local chemical environment of the rare earth ions (REI). More than 12 times enhancement of the emission at 2.9 and 3.5 ?m was achieved in glass-ceramics produced using prolonged annealing time. Elemental mapping showed clear evidence that Ga2S3 crystalline grains with a size of 50 nm were dispersed in a Ge-S glass matrix in the glass-ceramics, and the REI could only be found near the Ga2S3 crystalline grains. From the unchanged lineshape of the emissions at 2.9 and 3.5 ?m and lack of splitting of the absorption peaks, we concluded that the REI were bonded to Ga on the surface of the Ga2S3 crystals.

  3. Effect of co-doping Tm{sup 3+} ions on the emission properties of Dy{sup 3+} ions in tellurite glasses

    SciTech Connect

    Sasikala, T.; Rama Moorthy, L.; Mohan Babu, A.; Srinivasa Rao, T.

    2013-07-15

    The present work reports the absorption, photoluminescence and decay properties of singly doped Dy{sup 3+} and co-doped Dy{sup 3+}/Tm{sup 3+} ions in TeO{sub 2}+ZnO+K{sub 2}O+CaO (TZKC) glasses prepared by the melt quenching technique. The glassy nature of the host glass has been confirmed by X-ray diffraction analysis and the primary vibrational modes were determined from the Raman spectrum. Judd–Ofelt (JO) analysis has been used to calculate the radiative transition rates, branching ratios and radiative lifetime of the emitting {sup 4}F{sub 9/2} state. The effect of co-doping of different concentrations of Tm{sup 3+} ions on the emission properties of Dy{sup 3+} ions has been investigated. The decay profiles of the {sup 4}F{sub 9/2} level were fitted to double exponential as well as Inokuti–Hirayama (IH) model to determine the energy transfer rates between Dy{sup 3+} and Tm{sup 3+} ions. The energy transfer rates found to increase with the increase of Tm{sup 3+} ions concentration. The chromaticity coordinates and color purity of the emitted light for all glasses were determined. - Graphical abstract: The graphical abstract shows the emission spectra of Dy{sup 3+}, Tm{sup 3+} and Dy{sup 3+}/Tm{sup 3+} co-doped TZKC glasses recorded by exciting at 355 nm wavelength. - Highlights: • Zinc tellurite glasses doped with Dy{sup 3+}, Tm{sup 3+} and Dy{sup 3+}/Tm{sup 3+} ions were prepared. • XRD, DTA and Raman spectral measurements were recorded to know the nature of host. • Energy transfer occurs from Dy{sup 3+} ions to Tm{sup 3+} ions. • The color purity of the emitted light was determined.

  4. Strong white light in P2O5-Li2O-Yb2O3-Sb2O3 glass doped with Pr3+ion

    NASA Astrophysics Data System (ADS)

    Ming, Chengguo; Han, Yingdong; Song, Feng; Ren, Xiaobin; An, Liqun

    2013-01-01

    P2O5-Li2O-Yb2O3-Sb2O3 glasses doped with Pr3+ ion had been prepared to explore white-light-emitting materials. The photoluminescence spectra of the glasses were measured under 270 nm excitation. The emission color of the glass doped with 2 mol% Pr3+ ion was white to the naked eye, and the CIE coordinates (0.336, 0.319) of the sample were close to the standard equal energy white-light illumination (x=0.333, y=0.333). The present working mechanism of the commercial white-LEDs is that a yellow phosphor is excited by a blue LED chip. The emission characters are restricted by the intensity of the blue light and the thickness of the phosphor. However, the luminescent characters of our materials are not effected by the pumping light. Thus, our materials will be helpful in developing white-light-emitting materials.

  5. Intense 2.7 ?m and broadband 2.0 ?m emission from diode-pumped Er3+/Tm3+/Ho(3+)-doped fluorophosphate glass.

    PubMed

    Tian, Ying; Xu, Rongrong; Hu, Lili; Zhang, Junjie

    2011-08-15

    This Letter reports intense emission at 2.7 ?m and broadband emission at 2.0 ?m from Er(3+)/Tm(3+)/Ho(3+)-doped fluorophosphate glass. The fluorescence characteristics and energy transfer upon excitation of a conventional 980 nm laser diode are investigated. Based on the fluorescence spectra and lifetime measurement, the effect of Tm(3+) and Ho(3+) ions on intense 2.7 ?m emission in fluorophosphate glass is demonstrated. It is also found that the effective bandwidth of 2.0 ?m emission due to Tm(3+) and Ho(3+) ions can reach as high as 196 nm. These results indicate that the advantageous spectroscopic characteristics of Er(3+)/Tm(3+)/Ho(3+) triply doped fluorophosphate glass together with the outstanding thermal properties may become an attractive host for the mid-IR solid state lasers. PMID:21847213

  6. Optical response and magnetic characteristic of samarium doped zinc phosphate glasses containing nickel nanoparticles

    NASA Astrophysics Data System (ADS)

    Azmi, Siti Amlah M.; Sahar, M. R.

    2015-11-01

    A magnetic glass of composition 40ZnO-(58-x) P2O5-1Sm2O3-xNiO, with x=0.0, 1.0, 1.5 and 2.0 mol% is prepared by melt-quenching technique. The glass is characterized by X-ray diffraction, high-resolution transmission electron microscope (HRTEM), photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM) analysis. The X-rays diffraction confirms the amorphous nature of the glass while the HRTEM analysis reveals the presence of nickel nanoparticles in the glass samples. High-resolution TEM reveals that the lattice spacing of nickel nanoparticles is 0.35 nm at (100) plane. Photoluminescence emission shows the existence of four peaks that correspond to the transition from the upper level of 4G5/2 to the lower level of 6H5/2, 6H7/2, 6H9/2, and 6H11/2. It is observed that all peaks experience significant quenching effect with the increasing concentration of nickel nanoparticles, suggesting a strong energy transfer from excited samarium ions to the nickel ions. The glass magnetization and susceptibility at 12 kOe at room temperature are found to be in the range of (3.87±0.17×10-2-7.19±0.39×10-2) emu/g and (3.24±0.16×10-6-5.99±0.29×10-6) emu/Oe g respectively. The obtained hysteresis curve indicates that the glass samples are paramagnetic materials. The studied glass can be further used towards the development of magneto-optical functional glass.

  7. Enhanced 1.53 ?m radiative transition in Er3+/Ce3+ co-doped tellurite glass modified by B2O3 oxide

    NASA Astrophysics Data System (ADS)

    Yang, Fengjing; Huang, Bo; Wu, Libo; Zhou, Yaxun; Chen, Fen; Yang, Gaobo; Li, Jun

    2015-09-01

    Er3+/Ce3+ co-doped and B2O3 modified tellurite glasses with initial composition of TeO2-GeO2-Li2O-Nb2O5 were prepared using melt-quenching technique for potential applications in Er3+-doped fiber amplifiers (EDFAs) and lasers. The absorption spectra, fluorescence spectra, up-conversion spectra, Raman spectra and differential scanning calorimeter (DSC) curves of glass samples were measured to evaluate the effect of B2O3 modification on the 1.53 ?m band spectroscopic properties of Er3+, structural nature and thermal stability of glass hosts. It was shown that the introduction of an appropriate amount of B2O3 oxide can further improve the 1.53 ?m band fluorescence emission through an enhanced phonon-assisted energy transfer (ET) from Er3+ to Ce3+ ions under the excitation of 980 nm, and the quantitative studies were carried out to elucidate the ET mechanism via calculating the microscopic parameters and phonon contribution ratios. Meanwhile, the thermal stability of glass hosts increases slightly with the introduction of B2O3 oxide. Furthermore, the 1.53 ?m band optical signal amplification was simulated based on the rare-earth ion rate and light power propagation equations. An increment in signal gain by about 1.4 dB at 1532 nm was observed in the Er3+/Ce3+ co-doped tellurite glass fiber containing 6 mol% amount of B2O3 oxide, and the maximum signal gain reaches to 31 dB on a 50 cm fiber pumped at 980 nm with power 200 mW. The present results indicate that the prepared Er3+/Ce3+ co-doped tellurite glass modified by an appropriate amount of B2O3 oxide has good prospect as a gain medium applied for 1.53 ?m band EDFAs and lasers.

  8. Structural and spectroscopic characteristics of Eu3+-doped tungsten phosphate glasses

    NASA Astrophysics Data System (ADS)

    Dousti, M. Reza; Poirier, Gael Yves; de Camargo, Andrea Simone Stucchi

    2015-07-01

    Tungsten based phosphate glasses are interesting non-crystalline materials, commonly known for photochromic and electrochromic effects, but also promising hosts for luminescent trivalent rare earth ions. Despite very few reports in the literature, association of the host´s functionalities with the efficient emissions of the dopant ions in the visible and near-infrared spectra could lead to novel applications. This work reports the preparation and characterization of glasses with the new composition 4(Sb2O3)96-x(50WO3 50NaPO3)xEu2O3 where x = 0, 0.1, 0.25, 0.5 and 1.0 mol%, obtained by the melt quenching technique. The glasses present large density (?4.6 g cm-3), high glass transition temperature (?480 °C) and high thermal stability against crystallization. Upon excitation at 464 nm, the characteristic emissions of Eu3+ ions in the red spectral region are observed with high intensity. The Judd-Ofelt intensity parameters ?2 = 6.86 × 10-20, ?4 = 3.22 × 10-20 and ?6 = 8.2 × 10-20 cm2 were calculated from the emission spectra and found to be higher than those reported for other phosphate glass compositions. An average excited state lifetime value of 1.2 ms, was determined by fitting the luminescence decay curves with single exponential functions and it is comparable or higher than those of other oxide glasses.

  9. Enhanced luminescence of Tb{sup 3+}/Eu{sup 3+} doped tellurium oxide glass containing silver nanostructures

    SciTech Connect

    Kassab, Luciana R. P.; Araujo, Cid B. de

    2009-05-15

    We report on energy transfer studies in terbium (Tb{sup 3+})--europium (Eu{sup 3+}) doped TeO{sub 2}-ZnO-Na{sub 2}O-PbO glass containing silver nanostructures. The samples excitation was made using ultraviolet radiation at 355 nm. Luminescence spectra were recorded from approx =480 to approx =700 nm. Enhanced Eu{sup 3+} luminescence at approx =590 nm (transition {sup 5}D{sub 0}-{sup 7}F{sub 1}) and approx =614 nm (transition {sup 5}D{sub 0}-{sup 7}F{sub 2}) are observed. The large luminescence enhancement was obtained due to the simultaneous contribution of the Tb{sup 3+}-Eu{sup 3+} energy transfer and the contribution of the intensified local field on the Eu{sup 3+} ions located near silver nanostructures.

  10. Absolute quantum cutting efficiency of Tb{sup 3+}-Yb{sup 3+} co-doped glass

    SciTech Connect

    Duan, Qianqian; Qin, Feng; Zhang, Zhiguo; Zhao, Hua; Cao, Wenwu

    2013-12-07

    The absolute quantum cutting efficiency of Tb{sup 3+}-Yb{sup 3+} co-doped glass was quantitatively measured by an integrating sphere detection system, which is independent of the excitation power. As the Yb{sup 3+} concentration increases, the near infrared quantum efficiency exhibited an exponential growth with an upper limit of 13.5%, but the visible light efficiency was reduced rapidly. As a result, the total quantum efficiency monotonically decreases rather than increases as theory predicted. In fact, the absolute quantum efficiency was far less than the theoretical value due to the low radiative efficiency of Tb{sup 3+} (<61%) and significant cross-relaxation nonradiative loss between Yb{sup 3+} ions.

  11. Multicolor up-conversion emission in tellurite glasses co-doped with rare earth ions for white LED applications

    NASA Astrophysics Data System (ADS)

    Sienkiewicz, Pawe?; Palkowska, Anna; Pietrzycki, Marcin; Romanczuk, Patryk; Zmojda, Jacek; Kochanowicz, Marcin; Dorosz, Dominik

    2014-11-01

    In the article the glass with molar composition of 75TeO2-20ZnO-5Na2O co-doped with Yb3+/Tm3+/Ho3+ ions was fabricated by typical melt-quenching technique. Multicolour up-conversion emission at the wavelengths of 479 nm (blue), 546 nm (green) and 650 nm (red) corresponding to transitions 1G4 -->3H6 (Tm3+), 5F4-->5I8 (Ho3+) and 5F5-->5I8 (Ho3+), respectively have been observed under infrared excitation (?exc = 980 nm) at room temperature. Influence of molar ratio of active ions on the colour coordinates (CIE-1931) have been investigated.

  12. Magnetic nanoparticles-doped silica layer reported on ion-exchanged glass waveguide: towards integrated magneto-optical devices

    NASA Astrophysics Data System (ADS)

    Amata, Hadi; Royer, François; Choueikani, Fadi; Jamon, Damien; Broquin, Jean-Emmanuel; Plenet, Jean Claude; Rousseau, Jean Jaques

    2010-05-01

    In the framework of optical telecommunication systems, many functions are integrated on the same substrate. Nevertheless, one of the most important, such as isolation, is achieved using discrete components. It is based on magnetic materials which are always difficult to integrate with classical technologies. This is due to the annealing temperature of magnetic materials. In this paper we present another way for the realisation of such components. We use a dip coating process to report a magnetic nanoparticles doped silica layer on ion-exchanged glass waveguide. The advantages of this method is discussed and we demonstrate its compatibility with ion-exchanged technology. By varying the refractive index of the layer, we can adjust the interaction between the waveguide and the magneto-optical layer.

  13. Microstructural and optical characterizations of sol-gel based nanoclustered indium (III) doped cadmium(II) oxide films on glass

    NASA Astrophysics Data System (ADS)

    Ghosh, S. S.; Neogi, S.; Biswas, P. K.

    2014-12-01

    Thin films of indium doped cadmium oxide have been developed on glass by sol-gel dipping process. Four different In: Cd atomic ratios, 01: 99, 04: 96, 07: 93, 10: 90 were selected initially for the precursors to develop nanostructured films. Microstructure evaluation by SEM, FESEM and TEM experiments has led to the detailed study of the films of In: Cd = 10: 90 prepared in different atmospheres. XRD depicted cubic In2O3, CdO along with spinel CdIn2O4 and wurtzite CdO preferably in nitrogen atmosphere. Band gap evaluation highlighted the excitonic transitions for the occurrence of quantum confinement in the nanoclusters. Photoluminescence (PL) of the films exhibited the presence of free exciton, bound exciton and interaction of excitons with LO phonons of wurtzite CdO evidenced from the satellite peaks of PL emission bands.

  14. Spectroscopic properties and mechanism of Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Hu, Yue-Bo; Qiu, Jian-Bei; Zhou, Da-Cheng; Song, Zhi-Guo; Yang, Zheng-Wen; Wang, Rong-Fei; Jiao, Qing; Zhou, Da-Li

    2014-02-01

    Transparent Tm3+/Er3+/Yb3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode (LD), compared with the glass before heat treatment, the Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark-split peaks; X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm3+, Er3+ and (or) Yb3+ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm3+, Er3+ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.

  15. Picosecond nonradiative processes in neodymium-doped crystals and glasses: mechanism for the energy gap law

    SciTech Connect

    Bibeau, C.; Payne, S.A.

    1998-03-02

    This report presents measurements of the {sup 4}G{sub 7/2} emission for 26 nd-doped materials. A model of nonradiative decay based on dipole-dipole energy is developed and found to be supported by the data.

  16. The 1.53 ?m spectroscopic properties of Er3+/Ce3+/Yb3+ tri-doped tellurite glasses containing silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Bo; Zhou, Yaxun; Yang, Fengjing; Wu, Libo; Qi, Yawei; Li, Jun

    2016-01-01

    The metallic silver nanoparticles (NPs) was introduced into the Er3+/Ce3+/Yb3+ tri-doped tellurite glasses with composition TeO2-ZnO-La2O3 to improve the 1.53 ?m band fluorescence. The UV/Vis/NIR absorption spectra, 1.53 ?m band fluorescence spectra, fluorescence lifetimes, X-ray diffraction (XRD) curves, differential scanning calorimeter (DSC) curves and transmission electron microscopy (TEM) image of tri-doped tellurite glasses were measured, together with the Judd-Ofelt intensity parameters, emission cross-sections, absorption cross-sections and radiative quantum efficiencies were calculated to investigate the effects of silver NPs on the 1.53 ?m band spectroscopic properties of Er3+ ions, structural nature and thermal stability of glass hosts. It is shown that Er3+/Ce3+/Yb3+ tri-doped tellurite glasses can emit intense 1.53 ?m band fluorescence through the combined energy transfer (ET) processes from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions under the 980 nm excitation. At the same time, the introduction of an appropriate amount of silver NPs can further improve the 1.53 ?m band fluorescence owing to the enhanced local electric field effect induced by localized surface Plasmon resonance (LSPR) of silver NPs and the possible energy transfer from silver NPs to Er3+ ions, and an improvement by about 120% of fluorescence intensity is found in the studied Er3+/Ce3+/Yb3+ tri-doped tellurite glass containing 0.5 mol% amount of silver NPs with average diameter of ?15 nm. The energy transfer mechanisms from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions were also quantitatively investigated by calculating energy transfer microparameters and phonon contribution ratios. Furthermore, the thermal stability of glass host increases slightly with the introduction of silver NPs while the glass structure maintains the amorphous nature. The results indicate that the prepared Er3+/Ce3+/Yb3+ tri-doped tellurite glass with an appropriate amount of silver NPs is an excellent gain medium applied for 1.53 ?m band EDFA pumped with a 980 nm laser diode (LD).

  17. Structural investigations on sodium-lead borophosphate glasses doped with vanadyl ions.

    PubMed

    Srinivasulu, K; Omkaram, I; Obeid, H; Kumar, A Suresh; Rao, J L

    2012-04-12

    Electron paramagnetic resonance (EPR), optical absorption, and FT-IR spectra of vanadyl ions in the sodium-lead borophosphate (Na(2)O-PbO-B(2)O(3)-P(2)O(5)) (SLBP) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO(2+) ions. The spin Hamiltonian parameters g and A are found to be independent of the V(2)O(5) content and temperature. The values of the spin Hamiltonian parameters indicate that the VO(2+) ions in SLBP glasses are present in octahedral sites with tetragonal compression. The population difference between Zeeman levels (N) is calculated as a function of temperature for an SLBP glass sample containing 1.0 mol % VO(2+) ions. From the EPR data, the paramagnetic susceptibility (?) is calculated at different temperatures, and the Curie constant (C) is calculated from the 1/? versus T graph. The optical absorption spectra of the glass samples show two absorption bands, and they are attributed to V(3+) and V(4+) ions. The optical band gap energy (E(opt)) and Urbach energy (?E) are calculated from their ultraviolet absorption edges. It is observed that, as the vanadium ion concentration increases, E(opt) decreases and ?E increases. The study of the IR absorption spectrum depicts the presence of BO(3), BO(4), PO(3), PO(4), and VO(5) structural units. PMID:22409286

  18. Antimicrobial activity of borate-buffered solutions.

    PubMed Central

    Houlsby, R D; Ghajar, M; Chavez, G O

    1986-01-01

    A minimal salts medium adjusted to physiological pH and osmolality was buffered with either 0.3% phosphate or 1.2% borate and evaluated for antimicrobial activity. The borate-buffered medium, either with or without a carbon source, exhibited significant antimicrobial activity against 15 Pseudomonas strains, 12 strains of enteric bacteria, and 7 strains of staphylococci. The borate-buffered system appears suitable for use as a generic vehicle for ophthalmic pharmaceutical agents. PMID:3729341

  19. Spectroscopic properties of Er{sup 3+} doped lead telluroborate glasses for 1.5 ?m broadband amplifiers

    SciTech Connect

    Vijayakumar, R. Arunkumar, S. Vijayakumar, M. Marimuthu, K.

    2014-04-24

    Er{sup 3+} doped lead telluroborate glasses (xEPTB) with the composition 25B{sub 2}O{sub 3}-(25-x)TeO{sub 2}-25PbO-10Bi{sub 2}O{sub 3}-15CdO-xEr{sub 2}O{sub 3} (where x=0.1, 0.5, 1 and 2 wt%) have been prepared and characterised using NIR luminescence and decay measurements for 1.5 ?m broadband amplifier applications. Judd-Ofelt intensity parameters have been derived to predict radiative properties of the {sup 4}I{sub 13/2}?{sup 4}I{sub 15/2} emission transition. The larger values of stimulated emission cross-section (?P), FWHM, gain bandwidth (?G), radiative lifetime (?{sup cal}), quantum efficiency (?) of the 1EPTB glass suggest their potential use in broadband amplifiers. The effect of RE ion concentration and OH{sup ?} content on the lifetime of {sup 4}I{sub 13/2}?{sup 4}I{sub 15/2} transition and the energy transfer mechanism of Er{sup 3+} ions have also been discussed and reported in the present study.

  20. Optical spectroscopy and waveguide fabrication in Sm3+/Tb3+ doped zinc-sodium-aluminosilicate glasses

    NASA Astrophysics Data System (ADS)

    Caldiño, U.; Speghini, A.; Berneschi, S.; Bettinelli, M.; Brenci, M.; Pelli, S.; Righini, G. C.

    2012-05-01

    A spectroscopic investigation of sodium-zinc-aluminosilicate glasses activated with Sm3+ and Tb3+/Sm3+ ions is performed through their luminescence spectra and decay times. Yellowish-green light emission, with x = 0.37 and y = 0.58 CIE chromaticity coordinates, is obtained in the Tb3+/Sm3+ codoped glass excited at 318 nm. Such yellowish-green emission is generated by the simultaneous emission of Tb3+ and Sm3+ ions, samarium being sensitized by the terbium through a non-radiative energy transfer. From spectroscopic data it is inferred that this energy transfer takes place between Tb3+ and Sm3+ clusters through a short-range interaction mechanism. Optical waveguides are also effectively produced in the glasses by Ag+-Na+ ion exchange.

  1. Preparation and Characterization of Niobium Doped Lead-Telluride Glass Ceramics

    SciTech Connect

    Sathish, M.; Eraiah, B.; Anavekar, R. V.

    2011-07-15

    Niobium-lead-telluride glass ceramics of composition xNb{sub 2}O{sub 5}-(20-x) pbO-80TeO{sub 2}(where x = 0.1 mol% to 0.5 mol%) were prepared by using conventional melt quenching method. The prepared glass samples were initially amorphous in nature after annealed at 400 deg. c all samples were crystallized. This was confined by X-ray diffraction and scanning electron microscopy. The particle size of these glass ceramics have been calculated by using Debye-Scherer formula and the particle size is in the order of 15 nm to 60 nm. The scanning electron microscopy (SEM) photograph shows the presence of needle-like crystals in these samples.

  2. Soda-zinc-aluminosilicate glasses doped with Tb3+, Ce3+, and Sm3+ for frequency conversion and white light generation

    NASA Astrophysics Data System (ADS)

    Berneschi, Simone; Brenci, Massimo; Righini, Giancarlo C.; Bettinelli, Marco; Speghini, Adolfo; Caldiño, Ulises; Álvarez, Enrique; Chiasera, Alessandro; Valligatla, Sreeramulu; Ferrari, Maurizio

    2011-09-01

    Sodium-zinc-aluminosilicate (NaZAS) glasses doped with single or multiple rare earth ions (Ce3+, Tb3+, Sm3+) were synthesized, and their characteristics investigated by m-line spectroscopy, absorption and luminescence spectroscopy, and micro-Raman spectroscopy. Blue-white light, with x = 0.24 and y = 0.24 CIE chromaticity coordinates, was obtained for the Tb3+ singly-doped glass excited at 351 nm. In NaZAS glasses co-doped with Ce3+ and Tb3+ it was possible to observe a non-radiative energy transfer from Ce3+ to Tb3+ ions upon 320 nm excitation; the Ce3+-->Tb3+ energy transfer microscopic parameter and efficiency were obtained from the analysis of the cerium emission decay curve. Different concentrations of Ce3+ and Tb3+ ions in the same glass host give rise to blue and blue-green emissions, with different CIE coordinates. Optical waveguides were also produced in the samples by means of Ag+-Na+ ion exchange process, and characterized.

  3. Electrical, dielectric and spectroscopic studies on MnO doped LiI-AgI-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Moguš-Milankovi?, A.; Pavi?, L.; Srilatha, K.; Srinivasa Rao, Ch.; Srikumar, T.; Gandhi, Y.; Veeraiah, N.

    2012-01-01

    LiI-AgI-B2O3 glasses doped with different concentrations of MnO (ranging from 0 to 0.8 mol%) were prepared. Electrical and dielectric properties have been studied over a wide frequency range of 10-2 - 106 Hz and in the temperature range from 173 to 523 K. The valence states of manganese ions and their coordination in the glass network have been investigated using optical absorption, luminescence, and ESR spectroscopy. The analysis of the spectroscopic results has indicated that the manganese ions exist in both Mn2+ and Mn3+ states and occupy octahedral and tetrahedral positions. With increasing MnO concentration there is a gradual increase in the tetrahedral occupancy of Mn2+ ions at the expense of octahedral occupancy in the glass network. The results of dc conductivity have indicated that when T > ?D/2, the small polaron hopping model is appropriate and the conduction is adiabatic in the nature. Further, the analysis of experimental data indicates that there is a mixed, ionic and electronic, conduction. It has been observed that the electrical conductivity decreases as the concentration of MnO increases suggesting the electronic conduction controlled by polaron hopping between manganese ions. In the low temperature region, up to 250 K, the ac conductivity is nearly temperature independent and varies linearly with frequency, which can be explained by the quantum mechanical tunneling (QMT) model. The dielectric properties have been analyzed in the framework of complex dielectric permittivity and complex electrical modulus formalisms. The evolution of the complex permittivity as a function of frequency and temperature has been investigated.

  4. Silicon, iron and titanium doped calcium phosphate-based glass reinforced biodegradable polyester composites as bone analogous materials

    NASA Astrophysics Data System (ADS)

    Shah Mohammadi, Maziar

    Bone defects resulting from disease or traumatic injury is a major health care problem worldwide. Tissue engineering offers an alternative approach to repair and regenerate bone through the use of a cell-scaffold construct. The scaffold should be biodegradable, biocompatible, porous with an open pore structure, and should be able to withstand the applied forces. Phosphate-based glasses (PGs) may be used as reinforcing agents in degradable composites since their degradation can be predicted and controlled through their chemistry. This doctoral dissertation describes the development and evaluation of PGs reinforced biodegradable polyesters for intended applications in bone augmentation and regeneration. This research was divided into three main objectives: 1) Investigating the composition dependent properties of novel PG formulations by doping a sodium-free calcium phosphate-based glass with SiO2, Fe2O3, and TiO2. Accordingly, (50P2 O5-40CaO- xSiO2-(10-x)Fe2O3, where x = 10, 5 and 0 mol.%) and (50P2O5-40CaO-xSiO 2-(10-x)TiO2 where x = 10, 7, 5, 3 and 0 mol.%) formulations were developed and characterised. SiO2 incorporation led to increased solubility, ion release, pH reduction, as well as hydrophilicity, surface energy, and surface polarity. In contrast, doping with Fe2O 3 or TiO2 resulted in more durable glasses, and improved cell attachment and viability. It was hypothesised that the presence of SiO 2 in the TiO2-doped formulations could up-regulate the ionic release from the PG leading to higher alkaline phosphatase activity of MC3T3-E1 cells. 2) Incorporating Si, Fe, and Ti doped PGs as fillers, either as particulates (PGPs) or fibres (PGFs), into biodegradable polyesters (polycaprolactone (PCL) and semi-crystalline and amorphous poly(lactic acid) (PLA and PDLLA)) with the aim of developing degradable bone analogous composites. It was found that PG composition and geometry dictated the weight loss, ionic release, and mechanical properties of the composites. It was also hypothesised that a potential reaction between Si and the ester bond led to the formation of carboxylate by-products resulting in a lower molecular weight polymer, thus affecting the mechanical properties of the composites. Cytocompatibility assessment with MC3T3-E1 pre-osteoblasts showed that these composites were cytocompatible, and cell alignment along the PGFs was observed possibly due to their favourable ionic release properties. 3) Investigating the solid-state foaming using carbon dioxide (CO 2) of PDLLA-PGP composites with up to 30 vol.% filler content. While PDLLA foams resulted in 92% porosity, the porosity of the composites ranged between 79 and 91% which decreased with PGP content. In addition, a reduction in pore size was observed with increasing PGP content; however, the pore size maintained its range of 200-500 ?m in all composite foams, suitable for bone tissue engineering applications. The percentage of open pores increased significantly with PGP content (up to 78% at 30 vol.% PGP). Compressive strength and modulus of PDLLA-PGP foams showed up to approximately 3-fold increase at 30 vol.% PGP content compared to neat PDLLA foams.

  5. 23Na chemical shifts and local structure in crystalline, glassy, and molten sodium borates and germanates.

    PubMed

    George, A M; Sen, S; Stebbins, J F

    1997-12-01

    A simple correlation between average Na-O bond length and 23Na isotropic chemical shift in crystalline germanates and borates has been established, similar to existing correlations for sodium in silicates and carbonates. This empirical trend is discussed in terms of a decreasing paramagnetic contribution to the chemical shift with increasing average bond length. The correlation is then applied to data for sodium borate and germanate glasses and melts from room temperature to 1200 degrees C, where both structural and compositional effects on the chemical shift are apparent. PMID:9472786

  6. Investigation of thermal and spectroscopic properties of Bi2O3-GeO2-Ga2O3-Na2O glasses doped with Er3+ ions

    NASA Astrophysics Data System (ADS)

    Ragin, Tomasz; Czajkowski, Karol; ?mojda, Jacek; Kochanowicz, Marcin; Dorosz, Dominik

    2014-11-01

    Heavy metal oxide glasses based on the Bi2O3-GeO2-Ga2O3-Na2O system doped with Er3+ ions have been presented.. The influence of glass composition on thermal stability and luminescent properties has been presented. Fabricated glass exhibits emission at 1538 nm (Er3+: 4I13/2 --> 4I15/2) under 980 nm laser diode excitation. Due to different molar content of oxides in samples, various luminescence intensity was observed. High absorption cross-section allowed to determine the gain coefficient at the level of 3.47 cm-1 at the wavelength of 1538 nm. According to the results, fabricated bismuthgermanate glasses should be used for construction of optical waveguides operating in the range of near-infrared.

  7. An FTIR and ESR study of iron doped calcium borophosphate glass-ceramics

    NASA Astrophysics Data System (ADS)

    Karabulut, M.; Popa, A.; Borodi, G.; Stefan, R.

    2015-12-01

    A series of glasses in the xFe2O3-(100-x) [42B2O3-24CaO-34P2O5] system has been prepared for x = 0-10. Structure of as casted glasses and their heat treated counterparts have been studied by X-ray diffraction, infrared and electron spin resonance spectroscopies. Amorphous nature of all of the compositions studied is confirmed by the XRPD spectra. After the heat treatment, besides the main BPO4 phase, CaBPO5 and Ca(PO3) crystalline phases were identified in the iron free glass while B0.57Fe0.43PO4 phase was also observed in the XRD pattern of iron containing samples. FTIR spectra indicate changes in the glass network upon iron addition. X-band ESR spectra exhibits resonance signals at g ? 2.0 and g ? 4.3 for all analyzed samples. A supplementary line centered at g ? 6 appears after the thermal treatment. The nature of ESR absorption signals and influence of iron content on the evolution of ESR parameters are discussed.

  8. Enhanced 1.53 ?m fluorescence and energy transfer mechanism in tellurite glasses doped with Er3+/Ce3+/Yb3+

    NASA Astrophysics Data System (ADS)

    Yang, Fengjing; Huang, Bo; Wu, Libo; Peng, Shengxi; Qi, Yawei; Zhou, Yaxun

    2015-08-01

    Tellurite glasses (TeO2-ZnO-La2O3) doped with Er3+, Er3+/Ce3+ and Er3+/Ce3+/Yb3+ have been prepared using the melt-quenching technique, and the absorption spectra, fluorescence and up-conversion emission spectra together with the differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns were measured to evaluate the effects of Ce3+ and Yb3+ introduction on the 1.53 ?m band spectroscopic properties of Er3+, thermal stability and structural nature of glass hosts. The Judd-Ofelt intensity parameters ?t (t=2,4,6), spontaneous emission probabilities, radiative lifetimes and branching ratios of several Er3+ transitions were calculated from the measured absorption spectra based on the Judd-Ofelt theory. The co-doping with Ce3+ was effective on the suppression of up-conversion emission of Er3+ owing to the phonon-assisted energy transfer: Er3+:4I11/2+Ce3+:2F5/2?Er3+:4I13/2+Ce3+:2F7/2, while the co-doping with Yb3+ had the effect of obviously increasing the Er3+ population at 4I11/2 level via the resonant energy transfer: Yb3+:2F5/2+Er3+:4I15/2?Yb3+:2F7/2+Er3+:4I11/2, both of which contributed the effective enhancement of 1.53 ?m fluorescence emission. The quantitative studies were carried out to elucidate the energy transfer mechanism by calculating the microscopic parameters and phonon contribution ratios. The glass transition temperature (Tg), crystallization onset temperature (Tx) and the difference ?T (=Tx -Tg), which characterize the thermal stability of glass host, increased with the Ce3+ and Yb3+ co-doping and for all glass samples the value of ?T is larger than 145 °C. The glass structural nature was demonstrated from the measured XRD patterns with no sharp diffraction peaks. The results of the present work indicated that the prepared Er3+/Ce3+/Yb3+ co-doped tellurite glass is a potential material for developing broad-band and high-gain optical amplifiers and other optical devices.

  9. Fabrication and characterization of Er+3 doped SiO2/SnO2 glass-ceramic thin films for planar waveguide applications

    NASA Astrophysics Data System (ADS)

    Guddala, S.; Chiappini, A.; Armellini, C.; Turell, S.; Righini, G. C.; Ferrari, M.; Narayana Rao, D.

    2015-02-01

    Glass-ceramics are a kind of two-phase materials constituted by nanocrystals embedded in a glass matrix and the respective volume fractions of crystalline and amorphous phase determine the properties of the glass-ceramics. Among these properties transparency is crucial in particular when confined structures, such as, dielectric optical waveguides, are considered. Moreover, the segregation of dopant rare-earth ions, like erbium, in low phonon energy crystalline medium makes these structures more promising in the development of waveguide amplifiers. Here we are proposing a new class of low phonon energy tin oxide semiconductor medium doped silicate based planar waveguides. Er3+ doped (100-x) SiO2-xSnO2 (x= 10, 20, 25 and 30mol%), glass-ceramic planar waveguide thin films were fabricated by a simple sol-gel processing and dip coating technique. XRD and HRTEM studies indicates the glass-ceramic phase of the film and the dispersion of ~4nm diameter of tin oxide nanocrystals in the amorphous phase of silica. The spectroscopic assessment indicates the distribution of the dopant erbium ions in the crystalline medium of tin oxide. The observed low losses, 0.5±0.2 dB/cm, at 1.54 ?m communication wavelength makes them a quite promising material for the development of high gain integrated optical amplifiers.

  10. [Upconversion and mid-infrared fluorescence properties of Ho3+/Yb3+ co-doped 50SiO2-50PbF2 glass ceramic].

    PubMed

    Zhang, Xiao-guang; Ren, Guo-zhong; Yang, Huai

    2014-08-01

    In the present paper, the upconversion and mid-infrared fluorescence properties of Ho3+/Yb3+ co-doped 50SiO2- 50PbF2 glass ceramic (GC) were studied. The GC has the following composition (in mol%): 50SiO2-50PbF2-1YbF3-0. 5HoF3. The mixtures of about 10 g were placed in a corundum crucible and melted at 1000 degrees C for 15 min in a SiC electric furnace in air and then poured on a brass plate. The GCs were obtained just by heat treatment at 450 degrees C. The X-ray diffraction pattern of the GC indicates that very small size crystals were precipitated in the precursor glass by heat treatment. The GCs have as high transmittance as glasses. The GCs have higher absorption cross section and narrower absorption peaks compared to the corresponding glasses, indicating that fluoride is doped with Ho ions. The Judd-Ofelt intensity parameters were determined from the absorption spectrum and Judd-Ofelt theory. The omega2 value is 0.17 x 10(-20) cm2 lower than that of fluoride glass ZBLA (2.28 x 10(-20) cm2), because of Ho3+ doping in PbF2 microcrystal. The intense green upconversion light was observed in Ho3+/Yb3+ co-doped 50SiO2-50PbF2 GCs excited by 980 nm laser diode. A main emission band centered around 540 nm (green), and three week emission bands centered around 420 nm(violet), 480 nm (blue), and 650 nm (red) which correspond to the Ho3+ : ((5)F4-->(5)I8) ((5)G-->(5)I8), ((8)K3--(5)I8) and ((5)F5-->(5)I8) transitions, respectively, were simultaneously observed in GCs. Compared with the glass sample, GCs have significantly intension in the green and blue upconversion fluorescence, and not significant change in the red upconversion fluorescence. Those changes are because that Ho ion in GCs locates in lower phonon energy environment than in glasses. Lower phonon energy can make the nonradiative relaxation rate reduce, which improves the green light upconversion efficiency, at the same time reduces the population of the intermediate energy level ((5)I7) of the red light radiation. The 2.9 microm mid-infrared light was observed in GC sample, but not in glass precursor excited by 980 nm laser diode. PMID:25474934

  11. [Upconversion and mid-infrared fluorescence properties of Ho3+/Yb3+ co-doped 50SiO2-50PbF2 glass ceramic].

    PubMed

    Zhang, Xiao-guang; Ren, Guo-zhong; Yang, Huai

    2014-08-01

    In the present paper, the upconversion and mid-infrared fluorescence properties of Ho3+/Yb3+ co-doped 50SiO2- 50PbF2 glass ceramic (GC) were studied. The GC has the following composition (in mol%): 50SiO2-50PbF2-1YbF3-0. 5HoF3. The mixtures of about 10 g were placed in a corundum crucible and melted at 1000 degrees C for 15 min in a SiC electric furnace in air and then poured on a brass plate. The GCs were obtained just by heat treatment at 450 degrees C. The X-ray diffraction pattern of the GC indicates that very small size crystals were precipitated in the precursor glass by heat treatment. The GCs have as high transmittance as glasses. The GCs have higher absorption cross section and narrower absorption peaks compared to the corresponding glasses, indicating that fluoride is doped with Ho ions. The Judd-Ofelt intensity parameters were determined from the absorption spectrum and Judd-Ofelt theory. The omega2 value is 0.17 x 10(-20) cm2 lower than that of fluoride glass ZBLA (2.28 x 10(-20) cm2), because of Ho3+ doping in PbF2 microcrystal. The intense green upconversion light was observed in Ho3+/Yb3+ co-doped 50SiO2-50PbF2 GCs excited by 980 nm laser diode. A main emission band centered around 540 nm (green), and three week emission bands centered around 420 nm(violet), 480 nm (blue), and 650 nm (red) which correspond to the Ho3+ : ((5)F4-->(5)I8) ((5)G-->(5)I8), ((8)K3--(5)I8) and ((5)F5-->(5)I8) transitions, respectively, were simultaneously observed in GCs. Compared with the glass sample, GCs have significantly intension in the green and blue upconversion fluorescence, and not significant change in the red upconversion fluorescence. Those changes are because that Ho ion in GCs locates in lower phonon energy environment than in glasses. Lower phonon energy can make the nonradiative relaxation rate reduce, which improves the green light upconversion efficiency, at the same time reduces the population of the intermediate energy level ((5)I7) of the red light radiation. The 2.9 microm mid-infrared light was observed in GC sample, but not in glass precursor excited by 980 nm laser diode. PMID:25508713

  12. Role of magnesium during spontaneous formation of a calcium phosphate layer at the periphery of a bioactive glass coating doped with MgO

    NASA Astrophysics Data System (ADS)

    Jallot, E.

    2003-04-01

    The prerequisite for bioactive glasses to bond to living bone is the formation of biologically active apatites on their surface in the body. Reactions and bioactivity mechanisms between bioactive glasses and bone depend on the glass composition. Our results demonstrate this property of bioactivity for the studied bioactive glass. The bioactive glass doped with MgO leads to the formation of a Ca-P-Mg rich layer on top of a pure Si layer. Ca, P and Mg elements diffuse through the Si rich layer which seems to act as a protective diffusion barrier leading to t1/2 leaching kinetics. This paper demonstrates for the first time, the presence of Mg in the Ca-P rich layer at the interface between the bioactive glass and bone. However, magnesium influences the formation and the evolution of the apatite layer. Magnesium has synergistic effects on the crystallinity and solubility of apatites. These phenomena can promote a greater dissolution of the apatite precipitates in the studied bioactive glass. Determination of supersaturations values permits to better understand growth and dissolution of precipitates forming the apatite-Mg layer. Measurements of supersaturations for Ca, P and Mg were consistent before 3 months and after 6 months. Before 3 months, the apatite-Mg layer grows and after 3 months this layer is in dissolution.

  13. Concentration dependence of spectroscopic properties and energy transfer analysis in Nd3+ doped bismuth silicate glasses

    NASA Astrophysics Data System (ADS)

    Tian, Cong; Chen, Xi; Shuibao, Yu

    2015-10-01

    A detailed investigation on 1.06 ?m spectroscopic properties as a function of Nd3+ ions concentration in bismuth silicate glasses is reported. Judd-Ofelt analysis indicated that Nd2O3 has no substantial influence on glass structure. Based on the Judd-Ofelt intensity parameters, several radiative properties such as radiative transition probability, radiative lifetime, branching ratio and emission cross-section of Nd3+ ions have been derived. The 1.06 ?m emission intensity increases firstly and then attains maximum at 0.5 mol% Nd2O3 and decreases with further increase of dopant concentration. The luminescence quenching behavior at higher Nd3+ concentration has been ascribed to the hopping migration assisted cross relaxation mechanism. The high emission cross section (2.33 × 10-20 cm2) and large quantum efficiency (90.7%) suggests their potential for compact 1.06 ?m lasers applications.

  14. Modifications in silver-doped silicate glasses induced by ns laser beams

    NASA Astrophysics Data System (ADS)

    Cattaruzza, E.; Mardegan, M.; Trave, E.; Battaglin, G.; Calvelli, P.; Enrichi, F.; Gonella, F.

    2011-04-01

    Glass layers for planar light waveguides prepared by Ag-Na ion exchange of different silicate glasses in molten salt baths are annealed and/or irradiated with a laser beam in the UV region, with different energy density values and total pulse numbers. The samples are mainly characterized by optical absorption spectroscopy, luminescence spectroscopy, and Rutherford backscattering spectrometry, in order to determine the role of irradiation parameters and of the host matrix structure in the aggregation phenomena. Photoluminescence spectroscopy gave information regarding the presence of Ag multimeric aggregates, the primal seeds for the growing (nano)crystals. The appearance of the plasmon resonance band in the optical absorption spectra proved the formation of Ag clusters and allowed the evolution steps of the clusterization process to be followed as a function of the energy deposited during the laser irradiation.

  15. Ultraviolet-driven white light generation from oxyfluoride glass co-doped with Tm{sup 3+}-Tb{sup 3+}-Eu{sup 3+}

    SciTech Connect

    Kuznetsov, A. S.; Nikitin, A.; Tikhomirov, V. K.; Shestakov, M. V.; Moshchalkov, V. V.

    2013-04-22

    Tm{sup 3+}-Tb{sup 3+}-Eu{sup 3+} co-doped oxyfluoride glasses, doped with about 3.0 mol. % TmF{sub 3}, 0.25 mol. % TbF{sub 3}, and 0.25 mol. % EuF{sub 3}, have been prepared by melt quenching technique. Under excitation at commercial 365 nm, the rare-earth co-dopants are all directly excited and emit in the blue, green, and red, respectively, without appreciable energy transfer amongst the co-dopants. Tint of the white luminescence can be adjusted by changing the ratio of the co-dopants. Properties of the glass host promote excellent dissolution of the co-dopants and low non-radiative decay rate. The white emission at 365 nm excitation is suitable for light emitting diodes applications.

  16. Growth and melting of metallic nanoclusters in glass: A review of recent investigations

    NASA Astrophysics Data System (ADS)

    Kellermann, G.; Craievich, A. F.

    2008-12-01

    The mechanisms of nucleation and growth and the solid-to-liquid transition of metallic nanoclusters embedded in sodium borate glass were recently studied in situ via small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). SAXS results indicate that, under isothermal annealing conditions, the formation and growth of Bi or Ag nanoclusters embedded in sodium borate glass occurs through two successive stages after a short incubation period. The first stage is characterized by the nucleation and growth of spherical metal clusters promoted by the diffusion of Bi or Ag atoms through the initially supersaturated glass phase. The second stage is named the coarsening stage and occurs when the (Bi-or Ag-) doping level of the vitreous matrix is close to the equilibrium value. The experimental results demonstrated that, at advanced stages of the growth process, the time dependence of the average radius and density number of the clusters is in agreement with the classical Lifshitz-Slyozov-Wagner (LSW) theory. However, the radius distribution function is better described by a lognormal function than by the function derived from the theoretical LSW model. From the results of SAXS measurements at different temperatures, the activation energies for the diffusion of Ag and Bi through sodium borate glass were determined. In addition, via combination of the results of simultaneous WAXS and SAXS measurements at different temperatures, the crystallographic structure and the dependence of melting temperature T m on crystal radius R of Bi nanocrystals were established. The experimental results indicate that T m is a linear and decreasing function of nanocrystal reciprocal radius 1/ R, in agreement with the Couchman and Jesser theoretical model. Finally, a weak contraction in the lattice parameters of Bi nanocrystals with respect to bulk crystals was established.

  17. Growth and melting of metallic nanoclusters in glass: A review of recent investigations

    SciTech Connect

    Kellermann, G.; Craievich, A. F.

    2008-12-15

    The mechanisms of nucleation and growth and the solid-to-liquid transition of metallic nanoclusters embedded in sodium borate glass were recently studied in situ via small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). SAXS results indicate that, under isothermal annealing conditions, the formation and growth of Bi or Ag nanoclusters embedded in sodium borate glass occurs through two successive stages after a short incubation period. The first stage is characterized by the nucleation and growth of spherical metal clusters promoted by the diffusion of Bi or Ag atoms through the initially supersaturated glass phase. The second stage is named the coarsening stage and occurs when the (Bi-or Ag-) doping level of the vitreous matrix is close to the equilibrium value. The experimental results demonstrated that, at advanced stages of the growth process, the time dependence of the average radius and density number of the clusters is in agreement with the classical Lifshitz-Slyozov-Wagner (LSW) theory. However, the radius distribution function is better described by a lognormal function than by the function derived from the theoretical LSW model. From the results of SAXS measurements at different temperatures, the activation energies for the diffusion of Ag and Bi through sodium borate glass were determined. In addition, via combination of the results of simultaneous WAXS and SAXS measurements at different temperatures, the crystallographic structure and the dependence of melting temperature T{sub m} on crystal radius R of Bi nanocrystals were established. The experimental results indicate that T{sub m} is a linear and decreasing function of nanocrystal reciprocal radius 1/R, in agreement with the Couchman and Jesser theoretical model. Finally, a weak contraction in the lattice parameters of Bi nanocrystals with respect to bulk crystals was established.

  18. Er3+ doped phosphoniobate glasses and planar waveguides: structural and optical properties

    NASA Astrophysics Data System (ADS)

    Barbosa, A. J.; Dias Filho, F. A.; Maia, L. J. Q.; Messaddeq, Y.; Ribeiro, S. J. L.; Gonçalves, R. R.

    2008-07-01

    Phosphoniobate glasses with composition (mol%) (100-x)NaPO3-xNb2O5 (x varying from 11 to 33) were prepared and characterized by means of thermal analysis, Fourier transform infrared spectroscopy, Raman scattering and 31P nuclear magnetic resonance. The addition of Nb2O5 to the polyphosphate base glass leads to depolymerization of the metaphosphate structure. Different colors were observed and assigned as indicating the presence of Nb4+ ions, as confirmed by electron paramagnetic resonance measurements. The color was observed to depend on the glass composition and melting temperature as well. Er3+ containing samples were also prepared. Strong emission in the 1550 nm region was observed. The Er3+ 4I15/2 emission quantum efficiency was observed to be 90% and the quenching concentration was observed to be 1.1 mol% (1.45 × 1020 ions cm-3). Planar waveguides were prepared by Na+-K+-Ag+ ion exchange with Er3+ containing samples. Optical parameters of the waveguides were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique as a function of the ion exchange time and Ag+ concentration. The optimized planar waveguides show a diffusion depth of 5.9 µm and one propagating mode at 1550 nm.

  19. Excitation and luminescence of rare earth-doped lead phosphate glasses

    NASA Astrophysics Data System (ADS)

    Pisarska, J.; So?tys, M.; ?ur, L.; Pisarski, W. A.; Jayasankar, C. K.

    2014-09-01

    Excitation and luminescence properties of Eu3+, Tb3+ and Er3+ ions in lead phosphate glasses have been studied. From excitation spectra of Eu3+ ions, the electron-phonon coupling strength and phonon energy of the glass host were calculated and compared to that obtained by Raman spectroscopy. Main intense and long-lived luminescence bands are related to the 5D0-7F2 (red) transition of Eu3+, the 5D4-7F5 (green) transition of Tb3+ and the 4I13/2-4I15/2 (near-infrared) transition of Er3+. The critical transfer distances, the donor-acceptor interaction parameters and the energy transfer probabilities were calculated using the fitting of the luminescence decay curves from 5D0 (Eu3+), 5D4 (Tb3+) and 4I13/2 (Er3+) excited states. The energy transfer probabilities for Eu3+ (5D0), Tb3+ (5D4) and Er3+ (4I13/2) are relatively small, which indicates low self-quenching luminescence of rare earth ions in lead phosphate glasses.

  20. Fibre Tip Sensors for Localised Temperature Sensing Based on Rare Earth-Doped Glass Coatings

    PubMed Central

    Schartner, Erik P.; Monro, Tanya M.

    2014-01-01

    We report the development of a point temperature sensor, based on monitoring upconversion emission from erbium:ytterbium-doped tellurite coatings on the tips of optical fibres. The dip coating technique allows multiple sensors to be fabricated simultaneously, while confining the temperature-sensitive region to a localised region on the end-face of the fibre. The strong response of the rare earth ions to changing temperature allows a resolution of 0.1–0.3 °C to be recorded over the biologically relevant range of temperatures from 23–39 °C. PMID:25407907

  1. The influence of chlorine ion on the spectroscopic properties of ? and ?-doped fluorochloride glass

    NASA Astrophysics Data System (ADS)

    Fernández, J.; Balda, R.; Adam, J. L.

    1998-06-01

    The influence of local coordination ions on the optical properties of 0953-8984/10/23/007/img8 and 0953-8984/10/23/007/img9 in fluorochloride glass has been investigated by using steady-state and time-resolved laser excited site selective spectroscopy. From the thermal behaviour of lifetimes of the 0953-8984/10/23/007/img10 state, a 0953-8984/10/23/007/img11 dependence for the nonradiative Nd-Nd relaxation process has been found in the 10-90 K temperature range for 0953-8984/10/23/007/img8 concentration higher than 0.5 mol% which is in agreement with a two-site nonresonant process. In spite of the high content of fluorine in this glass, the presence of chlorine anions causes a significant effect on the spectral behaviour and relative quantum efficiency of 0953-8984/10/23/007/img8 emission as compared with those of pure fluoride glasses. The excitation wavelength dependence of the lifetimes of the 0953-8984/10/23/007/img10 state points to the existence of some site segregation for 0953-8984/10/23/007/img8 in this fluorochloride glass. This result is also confirmed by fluorescence line-narrowing experiments performed with 0953-8984/10/23/007/img9 in the same glass. The behaviour of both the line-narrowed fluorescence of the 0953-8984/10/23/007/img17 hypersensitive transition and the linewidth of the time-resolved resonant line-narrowed 0953-8984/10/23/007/img18 emission band as a function of the selective 0953-8984/10/23/007/img19 excitation wavelength indicates that homogeneous linewidths are dominated by relaxation time broadening caused by rapid phonon relaxation processes. These results together with the crystal field strength calculated as a function of excitation energy along the 0953-8984/10/23/007/img19 absorption band might be interpreted as indicating the existence of a crossover between the behaviour of fluorinelike and chlorinelike coordination anions. A discussion on the origin of this behaviour is given.

  2. Down-shifting by energy transfer in Dy 3+-Tb 3+ co-doped YF 3-based sol-gel nano-glass-ceramics for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Santana-Alonso, A.; Yanes, A. C.; Méndez-Ramos, J.; del-Castillo, J.; Rodríguez, V. D.

    2011-02-01

    Highly transparent sol-gel derived nano-glass-ceramics containing YF 3 nanocrystals doped with Dy 3+ or Tb 3+ and co-doped with Dy 3+-Tb 3+ have been successfully developed. A structural analysis and luminescence spectra features confirmed the incorporation of rare-earth ions into precipitated YF 3 nanocrystals, where efficient energy transfer from Dy 3+ to Tb 3+ takes place. Higher efficiency is obtained with increasing Tb 3+ concentration, and no quenching effects are observed. Observed luminescence features leads the way to enhance solar cell spectral response by down-shifting of the incident solar spectrum, with an extended absorption range from 300 to 500 nm, yielding to a predominant green emission by co-doping with Dy 3+ and Tb 3+ ions.

  3. Effect of B2O3 on the spectroscopic properties in Er3+/Ce3+ co-doped tellurite-niobium glass

    NASA Astrophysics Data System (ADS)

    Yin, Dan-dan; Zheng, Shi-chao; Qi, Ya-wei; Peng, Sheng-xi; Zhou, Ya-xun

    2013-09-01

    The high phonon energy oxide of B2O3 is introduced into the Er3+/Ce3+ co-doped tellurite-niobium glasses with composition of TeO2-Nb2O5-ZnO-Na2O. The absorption spectra, 1.53 ?m band fluorescence spectra, fluorescence lifetime and Raman spectra of Er3+ in glass samples are measured together with the calculations of Judd-Ofelt spectroscopic parameter, stimulated emission and absorption cross-sections, which evaluate the effect of B2O3 on the 1.53 ?m band spectroscopic properties of Er3+. It is shown that the introduction of an appropriate amount of B2O3 can further improve the 1.53 ?m band fluorescence intensity through an enhanced phonon-assisted energy transfer (ET) between Er3+/Ce3+ ions. The results indicate that the prepared Er3+/Ce3+ co-doped tellurite-niobium glass with an appropriate amount of B2O3 is a potential gain medium for the 1.53 ?m bandbroad erbium-doped fiber amplifier (EDFA).

  4. Enhanced green and red upconversion and 2.7 ?m emission from Er3+/Tm3+ co-doped bismuth germanate glass

    NASA Astrophysics Data System (ADS)

    Zhao, Guoying; Kuan, Pei-Wen; Fan, Huiyan; Hu, Lili

    2013-03-01

    This work studied the spectroscopic properties of Er3+/Tm3+ co-doped bismuth germanate glass. Through Tm3+ co-doping and 980 nm LD pumping, the enhanced green (2H11/2, 4S3/2?4I15/2) and red (4F9/2?4I15/2) upconversion emission as well as 2.7 ?m emission (4I11/2?4I13/2) of Er3+ ions were observed. Meanwhile, the 1.5 ?m emission (Er3+:4I13/2?4I15/2) is significantly suppressed. Broadband 1.8 ?m emission (Tm3+:3F4?3H6) is got. The luminescent characteristics and dominant energy transfer mechanisms between Er3+ and Tm3+ ions are investigated. The emission cross section at 2.7 ?m of this glass is found to be as high as 1.10 × 10-20 cm2. Therefore, the spectroscopic characteristics of Er3+/Tm3+ co-doped bismuth germanate glass indicate it is a potential active medium for optical upconversion and mid-infrared luminescence devices.

  5. Wideband Infrared Emission from Yb3+- and Nd3+-Doped Bi2O3-B2O3 Glass Phosphor for an Optical Coherence Tomography Light Source

    NASA Astrophysics Data System (ADS)

    Fuchi, Shingo; Sakano, Ayako; Takeda, Yoshikazu

    2008-10-01

    We have investigated the spectroscopic properties of Bi2O3-B2O3 glasses doped with Nd3+ and Yb3+ separately, and doubly doped with the same ions, in order to search for appropriate phosphors for an optical coherence tomography (OCT) light source. The effects of Yb3+ and Nd3+ co-doping and varying Yb3+ concentration on the spectrum shape were studied to obtain an optimum line shape for OCT. We successfully obtained a Gaussian-like shape spectrum from 5.0Yb2O3-1.0Nd2O3-46.0Bi2O3-46.0B2O3 (in nominal molar composition) with a full-width-at-half-maximum (FWHM) of 101 nm in the wavelength region around 1000 nm. This FWHM corresponds to a depth resolution of 4.5 µm, which is about twice that of conventional light emitting diodes (LEDs) and super luminescent diodes (SLDs). The Gaussian-like line shape is very important to suppress ghost images in OCT. These results indicate that a Yb3+, Nd3+ co-doped Bi2O3-B2O3 glass phosphor can indeed be applied as a new type of OCT light source.

  6. Feasibility of Silver Doped TiO2/Glass Fiber Photocatalyst under Visible Irradiation as an Indoor Air Germicide

    PubMed Central

    Pham, Thanh-Dong; Lee, Byeong-Kyu

    2014-01-01

    This study investigated the feasibility of using Ag-TiO2 photocatalyst supported on glass fiber (Ag-TiO2/GF) prepared by a sol-gel method as an indoor air germicide. An experimental model was designed to investigate the bacterial disinfection efficiency of Staphylococcus (Staph), the most popular bacterium in hospitals in Korea, by the Ag-TiO2/GF photocatalyst. The silver content in Ag/TiO2 was altered from 1 to 10% to investigate the optimal ratio of Ag doped on TiO2/glass fiber (TiO2/GF) for photocatalytic disinfection of Staph. This study confirmed that Ag in Ag-TiO2/GF could work as an electron sink or donor to increase photocatalytic activity and promote the charge separation of electron-hole pairs generated from TiO2 after photon absorption. Ag also acts as an intermediate agent for the transfer of photo-generated electrons from the valence band of TiO2 to an acceptor (O2 gas) to promote photo-oxidation processes. The photocatalytic disinfection activity of Ag-TiO2/GF under visible light increased with the increase in silver content up to 7.5% and then slightly decreased with further increasing silver content. The highest disinfection efficiency and disinfection capacity of Staph using 7.5% Ag-TiO2/GF were 75.23% and 20 (CFU?s?1?cm?2) respectively. The medium level of humidity of 60% ± 5% showed better photocatalytic disinfection than the lower (40% ± 5%) or higher (80% ± 5%) levels. PMID:24658408

  7. Raman Spectroscopic Characterization of Rare Earth Ions Doped Bismuth-Based Glasses

    SciTech Connect

    Pop, L.; Culea, E.; Bosca, M.; Culea, M.

    2007-04-23

    The xReO(1-x)[3Bi2O3{center_dot}PbO] glass systems with diferent rare earth ions (ReO = CeO2, Tb4O7) have been prepared and examined with the aim of determining their structural characteristics. Raman sprectroscopy and density measurements were used to characterize the samples. Raman spectroscopy data permitted to identify some of the structural units that built up the lead bismuthate vitreous network. Density data were used to calculate the Poisson's ratio in terms of the Makishima-Mackenzie model.

  8. Effect of Zn addition on non-resonant third-order optical nonlinearity of the Cu-doped germano-silicate optical glass fiber.

    PubMed

    Ju, Seongmin; Watekar, Pramod R; Jeong, Seongmook; Kim, Youngwoong; Han, Won-Taek

    2012-01-01

    Cu/Zn-codoped germano-silicate optical glass fiber was manufactured by using the modified chemical vapor deposition (MCVD) process and solution doping process. To investigate the reduction effect of Zn addition on Cu metal formation in the core of the Cu/Zn-codoped germano-silicate optical glass fiber, the optical absorption property and the non-resonant third-order optical nonlinearity were measured. Absorption peaks at 435 nm and 469 nm in the Cu/Zn-codoped germano-silicate optical glass fiber were contributed to Cu metal particles and ZnO semiconductor particles, respectively. The effective non-resonant optical nonlinearity, gamma, of the Cu/Zn-codoped germano-silicate optical glass fiber was measured to be 1.5097 W(-1) x km(-1) by using the continuous-wave self-phase modulation method. The gamma of the Cu/Zn-codoped germano-silicate optical glass fiber was about four times larger than that of the reference germano-silicate optical glass fiber without any dopants. The increase of the effective non-resonant optical nonlinearity, gamma, of the Cu/Zn-codoped germano-silicate optical glass fiber, can be attributed to the enhanced nonlinear polarization due to incorporated ZnO semiconductor particles and Cu metal ions in the glass network. The Cu/Zn-codoped germano-silicate optical glass fiber showed high nonlinearity and low transmission loss at the optical communication wavelength, which makes it suitable for high-speed-high-capacity optical communication systems. PMID:22524031

  9. Pulsed laser deposition of rare-earth-doped gallium lanthanum sulphide chalcogenide glass thin films

    NASA Astrophysics Data System (ADS)

    Pompilian, O. G.; Dascalu, G.; Mihaila, I.; Gurlui, S.; Olivier, M.; Nemec, P.; Nazabal, V.; Cimpoesu, N.; Focsa, C.

    2014-10-01

    Amorphous chalcogenide thin films are of high current interest for technological applications as optical storage media or waveguides for photonic integrated circuits. As part of a larger project including fs, ps and ns pulsed laser deposition regimes, Er- and Pr-doped GLS thin films were deposited by ns PLD, and their structural, chemical and optical properties were analyzed by optical and electronic microscopy, stylus profilometry, X-ray diffraction, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), energy-dispersive X-ray spectroscopy, variable-angle spectroscopic ellipsometry and optical transmission. Films deposited at moderate fluence (~4 J/cm2) in UV (266 nm) presented a good surface quality, while exhibiting acceptable composition uniformity and deviations from stoichiometry in line with the literature. Composition and optical properties dependences on the deposition conditions were investigated and discussed with respect to previous studies on similar systems.

  10. Effect of Mn2+ ions on the enhancement red upconversion emission of Mn2+/Er3+/Yb3+ tri-doped in transparent glass-ceramics

    NASA Astrophysics Data System (ADS)

    Kim Dan, Ho; Zhou, Dacheng; Wang, Rongfei; Jiao, Qing; Yang, Zhengwen; Song, Zhiguo; Yu, Xue; Qiu, Jianbei

    2014-12-01

    The glass and glass-ceramics samples with composition of 50SiO2-10AlF3-(30-x)BaF2-5TiO2-3.95LaF3- xMnCO3-0.05ErF3-1YbF3 (in mol%, x=0, 0.5, 0.8, 1.0, and 1.2) were prepared using the conventional quenching techniques. The effects of Mn2+ ions on the enhancement red upconversion emission of Mn2+/Er3+/Yb3+ tri-doped transparent glass-ceramics under the changing of heat treatment temperatures and concentrations of Mn2+ ions were investigated. The structural investigation carried out by X-ray diffraction (XRD), and transmission electron microscopy evidenced the formation of cubic Ba2LaF7 nanocrystals. The efficiency upconversion emission of Mn2+/Er3+/Yb3+ tri-doped was observed in the glass-ceramics. The upconversion mechanism and energy transfer between Mn2+-Yb3+ dimer and Er3+ ions were investigated.

  11. Model Investigation of Temperature and Concentration Dependent Luminescence of Erbium-doped Tellurite Glasses

    SciTech Connect

    Ghoshal, S. K.; Sahar, M. R.; Rohani, M. S.; Tewari, H. S.

    2011-11-22

    Improving the up-conversion efficiency is the key issue in tellurite glasses. The quantum efficiency, radiative transition rate and lifetimes of excited states are greatly influenced by the optical properties of the host material, ligand field, multiphonon relaxation processes, impurities, temperature and concentration of erbium ions. We develop a comprehensive 4-level model to examine the radiative and nonradiative (NR) decay processes for the green ({sup 4}S{sub 3/2}{yields}{sup 4}I{sub 15/2}) and red ({sup 4}F{sub 9/2}{yields}{sup 4}I{sub 15/2}) emission over a temperature range of (10-340 K) and concentration range of (0.1-4.5 mol.%). Concentration dependent enhancement and thermal quenching of efficiency for up-conversion is investigated using the derived rate equations. These features are attributed to the NR energy transfer processes, trapped impurity effects, and thermal assisted hopping. The unusual nature of temperature and concentration dependent quenching effects for green and red emission is queries for further investigations. It is further suggested that to achieve higher infrared to visible up-converted efficiency in tellurite glasses the NR channels for energy and charge transfer by phonon and impurity mediated process has to be minimized. Our results on pump power dependent emission intensity, quantum efficiency, luminescence intensity, radiative lifetimes, and transition probabilities are in conformity with other experimental findings.

  12. White light generation from Dy{sup 3+}-doped ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} glasses

    SciTech Connect

    Jayasimhadri, M.; Jang, Kiwan; Lee, Ho Sueb; Chen, Baojiu; Yi, Soung-Soo; Jeong, Jung-Hyun

    2009-07-01

    Dysprosium doped ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} (ZBP) glasses were prepared by a conventional melt quenching technique in order to study the luminescent properties and their utility for white light emitting diodes (LEDs). X-ray diffraction spectra revealed the amorphous nature of the glass sample. The present glasses were characterized by infrared and Raman spectra to evaluate the vibrational features of the samples. The emission and excitation spectra were reported for the ZBP glasses. Strong blue (484 nm) and yellow (574 nm) emission bands were observed upon various excitations. These two emissions correspond to the {sup 4}F{sub 9/2}->{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}->{sup 6}H{sub 13/2} transitions of Dy{sup 3+} ions, respectively. Combination of these blue and yellow bands gives white light to the naked eye. First time, it was found that ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} glasses efficiently emit white light under 400 and 454 nm excitations, which are nearly match with the emissions of commercial GaN blue LEDs and InGaN LED, respectively. CIE chromaticity coordinates also calculated for Dy{sup 3+}: ZBP glasses to evaluate the white light emission.

  13. Characterization of radiative properties of Nd{sub 2}O{sub 3} doped phosphate and silicate glasses for solid state laser

    SciTech Connect

    Nandi, P. Shukla, R. Goswami, M.; Sudarsan, V.

    2014-04-24

    Nd{sub 2}O{sub 3} doped calcium aluminium phosphate and calcium aluminium silicate glasses prepared to compare their absorption and emission properties. Radiative lifetime of the excited state {sup 4}F{sub 3/2} derived by Judd-Ofelt theory applied to the absorption spectra. Using the photoluminescence spectrometer the steady state emission and relaxation time from excited energy level recorded under green light excitation. Phosphate glass has higher emission cross-section, higher radiative lifetime but less quantum efficiency due to non-radiative quenching through hydroxyl ions compared to silicate glass for Nd{sup 3+}:{sup 4}F{sub 3/2}?{sup 4}I{sub 9/2} emission.

  14. Growth mechanism and optical properties of Ti thin films deposited onto fluorine-doped tin oxide glass substrate

    SciTech Connect

    Einollahzadeh-Samadi, Motahareh; Dariani, Reza S.

    2015-03-15

    In this work, a detailed study of the influence of the thickness on the morphological and optical properties of titanium (Ti) thin films deposited onto rough fluorine-doped tin oxide glass by d.c. magnetron sputtering is carried out. The films were characterized by several methods for composition, crystallinity, morphology, and optical properties. Regardless of the deposition time, all the studied Ti films of 400, 1500, 2000, and 2500?nm in thickness were single crystalline in the ?-Ti phase and also very similar to each other with respect to composition. Using the atomic force microscopy (AFM) technique, the authors analyzed the roughness evolution of the Ti films characteristics as a function of the film thickness. By applying the dynamic scaling theory to the AFM images, a steady growth roughness exponent ??=?0.72?±?0.02 and a dynamic growth roughness exponent ??=?0.22?±?0.02 were determined. The value of ? and ? are consistent with nonlinear growth model incorporating random deposition with surface diffusion. Finally, measuring the reflection spectra of the samples by a spectrophotometer in the spectral range of 300–1100?nm allowed us to investigate the optical properties. The authors observed the increments of the reflection of Ti films with thickness, which by employing the effective medium approximation theory showed an increase in thickness followed by an increase in the volume fraction of metal.

  15. 1.319 ?m excited intense 800 nm frequency upconversion emission in Tm3+-doped fluorogermanate glass

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, A. S.; Vermelho, M. V. D.; Gouveia, E. A.; Bueno, L. A.; Jacinto, C.

    2015-11-01

    Generation of near-infrared light within the first biological optical window via frequency upconversion in Tm3+-doped PbGeO3-PbF2-CdF2 glass excited within the second biological window at 1.319 ?m is reported. The upconversion emission at 800 nm is the sole light signal observed in the entire ultraviolet-visible-near-infrared spectral region making it possible obtaining high contrast imaging. The dependence of the 800 nm signal upon the sample temperature was investigated and results showed an increase by a factor of ×2.5 in the 30-280 °C range. Generation of detectable 690 nm for temperatures above 100 °C in addition to the intense 800 nm main signal was also observed. The proposed excitation mechanism for the 800 nm thulium emitting level is assigned to a multiphonon-assisted excitation from the ground-state 3H6 to the 3H5 excited-state level, a rapid relaxation to the 3F4 level and followed by an excited-state absorption of the pump photons mediated by multiphonons connecting the 3F4 level to the 3H4 emitting level.

  16. Photocatalytic degradation of glyphosate in water by N-doped SnO2/TiO2 thin-film-coated glass fibers.

    PubMed

    Kongsong, Peerawas; Sikong, Lek; Niyomwas, Sutham; Rachpech, Vishnu

    2014-01-01

    Photocatalytic degradation of glyphosate contaminated in water was investigated. The N-doped SnO2/TiO2 films were prepared via sol-gel method, and coated on glass fibers by dipping method. The effects of nitrogen doping on coating morphology, physical properties and glyphosate degradation rates were experimentally determined. Main variable was the concentration of nitrogen doping in range 0-40 mol%. Nitrogen doping results in shifting the absorption wavelengths and narrowing the band gap energy those lead to enhancement of photocatalytic performance. The near optimal 20N/SnO2/TiO2 composite thin film exhibited about two- and four-folds of glyphosate degradation rates compared to the undoped SnO2/TiO2 and TiO2 films when photocatalytic treatment were performed under UV and solar irradiations, respectively, due to its narrowest band gap energy (optical absorption wavelength shifting to visible light region) and smallest crystallite size influenced by N-doping. PMID:25169246

  17. Advanced materials for aerospace and biomedical applications: New glasses for hermetic titanium seals

    SciTech Connect

    Brow, R.K.; Tallant, D.R.; Crowder, S.V.

    1996-11-01

    Titanium and titanium alloys have an outstanding strength-to-weight ratio and corrosion resistance and so are materials of choice for a variety of aerospace and biomedical applications. Such applications are limited by the lack of a viable hermetic glass sealing technology. Conventional silicate sealing glasses are readily reduced by titanium to form interfacial silicides that are incompatible with a robust glass/metal seal. Borate-based glasses undergo a similar thermochemistry and are reduced to a titanium boride. The kinetics of this reactions, however, are apparently slower and so a deleterious interface does not form. Chemically durable lanthanoborate glasses were examined as candidate sealing compositions. The compositions, properties, and structures of several alkaline earth, alumina, and titania lanthanoborate glass forming systems were evaluated and this information was used as the basis for a designed experiment to optimize compositions for Ti-sealing. A number of viable compositions were identified and sealing procedures established. Finally, glass formation, properties, and structure of biocompatible Fe{sub 2}O{sub 3}- and TiO{sub 2}-doped calcium phosphate systems were also evaluated.

  18. Intense 2.7 µm emission and structural origin in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass.

    PubMed

    Guo, Yanyan; Li, Ming; Hu, Lili; Zhang, Junjie

    2012-01-15

    The 2.7 ?m emission properties in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass were investigated in the present Letter. An intense 2.7 ?m emission in Er3+-doped bismuthate glass was observed. It is found that Er3+-doped bismuthate glass possesses high spontaneous transition probability A (65.26 s(-1)) and large 2.7 ?m emission cross section ?(em) (9.53×10(-21) cm2) corresponding to the stimulated emission of Er3+:4I11/2?4I13/2 transition. The emission characteristic and energy transfer process upon excitation of a conventional 980 nm laser diode in bismuthate glass were analyzed. Additionally, the structure of bismuthate glass was analyzed by the Raman spectrum. The advantageous spectroscopic characteristics of Er3+ single-doped bismuthate glass together with the prominent thermal property indicate that bismuthate glass might become an attractive host for developing solid-state lasers around 2.7 ?m. PMID:22854489

  19. Transparent oxyfluoride glass ceramics co-doped with Er{sup 3+} and Yb{sup 3+} - Crystallization and upconversion spectroscopy

    SciTech Connect

    Gugov, I.; Mueller, M.; Ruessel, C.

    2011-05-15

    Transparent glass ceramics in the system SiO{sub 2}-B{sub 2}O{sub 3}-PbO-CdO-PbF{sub 2}-CdF{sub 2}-YbF{sub 3}-ErF{sub 3} showing infrared to visible anti-Stokes (upconversion) luminescence are studied in the present work. The glass compositions have been optimized in order to reduce the melting temperature and, hence, to obtain laboratory scale samples with good optical quality. Erbium-doped nanoscale Pb{sub 4}Yb{sub 3}F{sub 17} crystals are precipitated in the precursor glasses during annealing at temperatures 30-40 K above T{sub g}. A kinetically self-constrained growth explains the nano sizes of the crystals. Both the Stokes and anti-Stokes luminescence spectra of glasses could be explained with clustering of the Yb{sup 3+} and Er{sup 3+} ions in fluorine-rich regions. At the annealing temperature these regions act as nucleation precursors. The crystal growth further enhances the local concentration of these ions. Consequently, a series of energy transfer and energy cross relaxation processes occurs between adjacent rare earth ions leading to the observed luminescence spectra of the glass ceramics studied. -- Graphical abstract: A highly viscous shell (shown in the picture in dark blue) is build around the growing crystal (white circles). When the shell's T{sub g} approaches the annealing temperature, the crystal growth is fully suppressed for kinetic reasons. The upconversion luminescence, resulting from the simultaneous absorption of two and even three infrared photons, is depicted schematically in the right part of the figure. Display Omitted Highlights: {yields} New oxyfluoride glass compositions with reduced melting temperature are formulated. {yields} The phase Pb{sub 4}Yb{sub 3}F{sub 17} doped with Er{sup 3+} ions crystallizes in these glasses. {yields} A kinetically self-constrained growth explains the nano sizes of the crystals. {yields} Clustering of Yb{sup 3+}, Er{sup 3+} and Pb{sup 2+} ions into fluorine-rich glass regions is observed. {yields} The luminescence of glass-ceramics is consistent with its structure.

  20. Structural and luminescence study of antimony-zinc borophosphate glass doped with iron

    NASA Astrophysics Data System (ADS)

    Pang, Xie Guan; Eeu, Tien Yew; Leow, Ting Qiao; Shamsuri, Wan Nurulhuda Wan; Hussin, Rosli

    2013-05-01

    Antimony zinc borophosphate glass were prepared with the composition of 20ZnO-30B2O3-xP2O5-(50-x)Sb2O3-2Fe2O3 (0?x?50 mol%) using the melt quenching method. The starting materials were mixed and preheat for 30 minutes and transfer into high temperature furnace for melting. The structure of samples were measured using Fourier-Transform Infrared (FT-IR) Spectroscopy. The spectra showed that network structure in the samples are mainly based on P=O, PO2, P-O, B-O-B and B-O units. With increasing P2O5 content, the vibration of P-O tends to shift towards lower wavenumber. Meanwhile, the luminescence was studied using Photoluminescence (PL) Spectroscopy. The samples were excited at specific wavelengths (265 - 300 nm). The emission profiles were obtained to study the energy transfer process. Luminescence of violet colour from samples were also recorded to correlate with PL results.

  1. Spectroscopic Investigation of Sm3+ doped phosphate based glasses for reddish-orange emission

    NASA Astrophysics Data System (ADS)

    Nayab Rasool, Sk.; Rama Moorthy, L.; Jayasankar, C. K.

    2013-01-01

    Spectroscopic properties of Sm3+ ions in phosphate based glasses (P2O5+K2O+Al2O3+CaF2) were investigated through SEM with EDS, X-ray diffraction (XRD), differential thermal analysis (DTA), Fourier transform infrared (FTIR), Raman, absorption, emission and decay measurements. Judd-Ofelt (JO) intensity parameters were obtained from the absorption spectrum which are inturn used to calculate the emission properties such as radiative transition probabilities (AR), radiative lifetime (?R), branching ratios (?R) and stimulated emission cross-sections (?e(?P)) for the 4G5/2??6HJ (J=5/2,7/2,9/2 and 11/2) transitions of Sm3+ ions. The effective fluorescence bandwidth (??eff) and the experimental branching ratios (?exp) were determined from the emission spectrum. The decay profiles of 4G5/2 level exhibited non- exponential nature with the increase of Sm3+ ions concentration. The non-exponential behavior of decay curves has been explained by using the Inokuti-Hirayama (IH) model for S=6, which indicates that the energy transfer mechanism is dipole-dipole between the Sm3+ ions.

  2. Effect of thermal annealing on the spectroscopic parameters of Er3+-doped sodium silicate glass

    NASA Astrophysics Data System (ADS)

    de Morais, Rodrigo F.; Serqueira, Elias Oliveira; Dantas, Noelio Oliveira

    2013-10-01

    This paper presents the optical characteristics of Er3+ ions in sodium silicate glass (SiO2-Na2O), synthesized by the fusion method and later annealed for 0, 30, 60 and 90 min. Thermograms, X-ray diffraction, optical absorption, luminescence spectroscopy measurements were performed in order to determine the thermal and structural of the samples and the radiative characteristics of Er3+ ions under influence of thermal annealing of the samples. Differential thermal analysis provided evidence of a phase change in the system. This phase change was confirmed by X-ray diffraction, which showed the formation and growth of Na2SiO3 crystals for the annealed samples. These crystals affect the neighborhood (from second vicinity) of Er3+ ions. These effects were noted by the J-O parameters (?2 and ?4), which were calculated from the optical absorption spectra. Judd-Ofelt calculations also confirmed that heat treatment induced structural rearrangement of the samples that was dependent on Er2O3 concentration. This resulted in changes in the optical and physical properties of the samples, including stimulated emission cross section and rigidity. Analysis of the spectroscopy parameters after of thermal annealing indicate samples are potential materials for in optical device applications.

  3. Influence of modifiers on the spectroscopic properties of Sm3+ ions doped sodium fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Mariyappan, M.; Arunkumar, S.; Marimuthu, K.

    2015-06-01

    Effect of Bi2O3/Na2O on the luminescence behavior of Sm3+ ions in Sodium fluoroborate glasses with the composition 40B2O3+xBi2O3+(40-x)Na2CO3+19CaF2+1Sm2O3 (where x= 0, 10, 20 30 and 40 in wt%) have been examined through absorption, luminescence and decay analysis. Optical energy gap (Eopt), Urbach energy (?E), Bonding parameters (?), Oscillator strengths (f) and Judd-Ofelt parameters have been determined and their features are reported. By using the JO intensity parameters various radiative properties like transition probability (A), stimulated emission cross-section (?PE ), calculated lifetime (?cal), branching ratios (?R) and effective bandwidth (??eff) are calculated and reported. The decay curves corresponding to the4G5/2 excited level of the Sm3+ ions are found to be non-exponential due to the efficient energy transfer between Sm3+-Sm3+ ions and the results have been discussed and reported.

  4. Glass forming ability and enhanced 2.7 ?m emission of erbium ions in TeO2 doped fluoroaluminate glass

    NASA Astrophysics Data System (ADS)

    Wang, Fengchao; Tian, Ying; Cai, Muzhi; Jing, Xufeng; Zhang, Junjie; Xu, Shiqing

    2015-10-01

    New fluoroaluminate-tellurite glasses were fabricated by introducing TeO2 into the fluoroaluminate glass. The glass-forming ability and crystallization kinetic parameter kD(T) of the fluoroaluminate-tellurite glass system as a function of the TeO2 concentrations were investigated by differential scanning calorimetry (DSC). Also, the crystalline phases were determined by X-ray diffraction (XRD). X-ray diffraction showed that the sample without TeO2 composition had some crystallization phases when the glass was reheated. However, the addition of TeO2 changed the crystallization ability and improved the glass forming ability of the fluoroaluminate glass. Besides, 2.7 ?m emission properties were investigated through the measured emission spectra. Enhanced 2.7 ?m emission was observed in the fluoroaluminate-tellurite glass under 980 nm excitation and the calculated emission cross section (?e) was larger than some reported values. This kind of fluoroaluminate-tellurite glass with excellent glass-forming ability and emission properties could be used as host material for optical fiber and 2.7 ?m lasers.

  5. Structure and intense UV up-conversion emissions in RE3+-doped sol-gel glass-ceramics containing KYF4 nanocrystals

    NASA Astrophysics Data System (ADS)

    Yanes, A. C.; Santana-Alonso, A.; Méndez-Ramos, J.; del-Castillo, J.

    2013-12-01

    Transparent nano-glass-ceramics containing KYF4 nanocrystals were successfully obtained by the sol-gel method, doped with Eu3+ and co-doped with Yb3+ and Tm3+ ions. Precipitation of cubic KYF4 nanocrystals was confirmed by X-ray diffraction and high-resolution transmission electron microscope images. Excitation and emission spectra let us to discern between ions into KYF4 nanocrystals and those remaining in a glassy environment, supplemented with time-resolved photoluminescence decays, that also clearly reveal differences between local environments. Unusual high-energy up-conversion emissions in the UV range were obtained in Yb3+-Tm3+ co-doped samples, and involved mechanisms were discussed. The intensity of these high-energy emissions was analyzed as a function of Yb3+ concentration, heat treatment temperature of precursor sol-gel glasses and pump power, determining the optimum values for potential optical applications as highly efficient UV up-conversion materials in UV solid-state lasers.

  6. Broadband near-infrared emission property in Er3+/Ce3+ co-doped silica-germanate glass for fiber amplifier.

    PubMed

    Wei, Tao; Chen, Fangze; Tian, Ying; Xu, Shiqing

    2014-05-21

    Er(3+) doped and Er(3+)/Ce(3+) co-doped silica-germanate glasses were synthesized by high-temperature melt-quenching technique. A detailed study of the 1.53?m spectroscopic properties and thermal stability was presented in this work. The absorption spectra, 1.53?m emission spectra and fluorescence lifetimes were measured and investigated, along with the quantitative calculations and analyses of Judd-Ofelt intensity parameters, stimulated absorption and emission cross-sections and the product of FWHM×?em(p). It was found that the prepared samples have outstanding thermal stability (Tg=585°C), large FWHM (77nm and 108nm) and high stimulated emission cross-sections (9.55×10(-28)cm(3) and 8.72×10(-28)cm(3)) of Er(3+). The 1.53?m fluorescence intensity improved significantly with the introduction of Ce(3+). Furthermore, the wavelength dependent gain coefficient G(?) of (4)I13/2?(4)I15/2 transition of Er(3+) was determined by means of the absorption and emission cross-sections. The results indicate that the developed glass co-doped with Er(3+)/Ce(3+) is a promising gain medium applied for broadband amplifier pumped with a 980nm laser diode. PMID:24583472

  7. Broadband near-infrared emission property in Er3+/Ce3+ co-doped silica-germanate glass for fiber amplifier

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Chen, Fangze; Tian, Ying; Xu, Shiqing

    Er3+ doped and Er3+/Ce3+ co-doped silica-germanate glasses were synthesized by high-temperature melt-quenching technique. A detailed study of the 1.53 ?m spectroscopic properties and thermal stability was presented in this work. The absorption spectra, 1.53 ?m emission spectra and fluorescence lifetimes were measured and investigated, along with the quantitative calculations and analyses of Judd-Ofelt intensity parameters, stimulated absorption and emission cross-sections and the product of FWHM×?emp. It was found that the prepared samples have outstanding thermal stability (Tg = 585 °C), large FWHM (77 nm and 108 nm) and high stimulated emission cross-sections (9.55 × 10-28 cm3 and 8.72 × 10-28 cm3) of Er3+. The 1.53 ?m fluorescence intensity improved significantly with the introduction of Ce3+. Furthermore, the wavelength dependent gain coefficient G(?) of 4I13/2 ? 4I15/2 transition of Er3+ was determined by means of the absorption and emission cross-sections. The results indicate that the developed glass co-doped with Er3+/Ce3+ is a promising gain medium applied for broadband amplifier pumped with a 980 nm laser diode.

  8. Novel synthesis of tripodal borate ligands 

    E-print Network

    Sanchez Perucha, Alejandro; Perucha, Alejandro Sanchez

    2007-06-25

    Poly(azolyl)borate ligands have proven to be extremely popular ligands since their introduction by Trofimenko in the late 60´s. The basic skeleton of these ligands involves usually three heterocycle units linked to a ...

  9. Absorption spectra and Raman gain coefficient in near-IR region of Er3+ ions doped TeO2-Nb2O5-Bi2O3-ZnO glasses

    NASA Astrophysics Data System (ADS)

    Yousef, El Sayed; Hegazy, H. H.; Almojadah, Samar; Reben, M.

    2015-11-01

    Er3+ ions doped TeO2 based glasses were prepared by quenching melting technique. A systematic characterization of glass transition temperature and optical properties of the prepared glass was carried out. The gain cross-section for the Er3+laser transition 4I13/2?4I15/2 was calculated. The results show the TNBZ glass doped with 2000 ppm of Er2O3 had the maximum value of gain cross-section equal to 14.4 cm-1 and large stimulated emission cross-section (1.4×10-20 cm2). The glasses developed here showed the widest bandwidths of gain cross section from 249 to 1106 cm-1. Moreover the Raman gain coefficient of the present glass was obtained from Raman scattering experiments using 532 nm excitation. This composition has also the maximum value of Raman gain coefficient (g=1.4×10-10 m/W) and it has the highest value of full width half maximum (FWHM? 380 cm-1). Finally, the structure of the prepared glasses was investigated through deconvolution Raman spectra. The thermal stability and spectroscopic properties indicate that this glass doped with Er3+ is a promising candidate for fiber lasers and Raman gain amplifiers.

  10. Energy transfer characteristics of silicate glass doped with Er{sup 3+}, Tm{sup 3+}, and Ho{sup 3+} for ?2 ?m emission

    SciTech Connect

    Li, Ming; Liu, Xueqiang; Graduate School of Chinese Academy of Sciences, Beijing 100039 ; Guo, Yanyan; Hu, Lili; Zhang, Junjie

    2013-12-28

    A Er{sup 3+}/Tm{sup 3+}/Ho{sup 3+} tri-doped silicate glass with good thermal stability is prepared by melt-quenching method. Efficient ?2 ?m emission is observed under 808 nm laser excitation. It is found that the 2.0 ?m emission of Ho{sup 3+} can be enhanced under the excitation at 808 nm by incorporating Er{sup 3+} and Tm{sup 3+}. Based on the measurement of absorption spectra, the Judd–Ofelt intensity parameters, radiation emission probability, and branching ratio are calculated to evaluate the spectroscopic properties simultaneously. The maximum value of emission cross section of Ho{sup 3+} is 3.54 × 10{sup ?21} cm{sup 2} at 2008 nm. Additionally, the phonon assistance and the micro-parameters in the energy transfer process are quantitatively analyzed by using Dexter model. The energy transfer coefficient from Tm{sup 3+} to Ho{sup 3+} can reach as high as 21.44 × 10{sup ?40} cm{sup 6}/s, respectively. The emission property together with good thermal property indicates that Er{sup 3+}/Tm{sup 3+}/Ho{sup 3+} tri-doped silicate glass is a potential kind of laser glass for efficient 2 ?m laser.

  11. Size-dependent luminescence of Sm3+ doped SnO2 nano-particles dispersed in sol-gel silica glass

    NASA Astrophysics Data System (ADS)

    Yanes, A. C.; Méndez-Ramos, J.; del-Castillo, J.; Velázquez, J. J.; Rodríguez, V. D.

    2010-12-01

    Sol-gel glasses with composition (100- x)SiO2- xSnO2 doped with 0.4 mol% of Sm3+, with x ranging from 1 to 10, have been successfully synthesized. Transparent doped nano-glass-ceramics were prepared by thermal treatment of the precursor glasses at 900°C during 4 hours, leading to nanocomposites comprising SnO2 nanocrystals embedded into an amorphous SiO2 phase. A structural analysis in terms of X-ray Diffraction and High Resolution Transmission Electron Microscopy confirms the precipitation of SnO2 nanocrystals within the glassy matrix. The mean radius of the obtained SnO2 nanocrystals, ranging from 2.1 to 4.7 nm calculated by the Scherrer and Brus equations, similar to the Bohr's exciton radius, constitutes a wide band-gap semiconductor quantum-dot system. Energy transfer from SnO2 nanocrystal host to Sm3+ ions is confirmed by luminescence spectra and analyzed as a function of SnO2 concentration, showing an evolution that could be ascribed to selective excitation of nanocrystal sets with predetermined size. Besides, a study of the luminescence as a function of temperature helps to clarify the involved energy transfer mechanisms.

  12. Recent progress in actinide borate chemistry

    SciTech Connect

    Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2011-01-01

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB?O?(OH)?][BO(OH)?]·2.5H?O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO4- Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials.

  13. Synthesis and study on the luminescence properties of cadmium borate phosphors

    SciTech Connect

    Annalakshmi, O.; Jose, M.T.; Venkatraman, B.; Amarendra, G.

    2014-02-01

    Highlights: • Cadmium borate synthesized by solid state sintering technique. • Neutron sensitivity of the material ten times that of TLD-600. • Gamma sensitivity is found to be twice that of TLD-100. • Gamma response is linear from 0.1 to 10{sup 3} mGy. - Abstract: Cadmium borate compound prepared through wet chemical reaction from the starting chemicals followed by high temperature solid state synthesis below the melting point to get the final TL phosphor powder. Phase purity and bond details of cadmium borate crystals are characterized using X-ray diffraction technique and infrared spectroscopy. Feasibility of these materials for radiation dosimetry applications was studied after gamma and neutron irradiation. Gamma irradiation of undoped phosphors show a single peak around 185 °C whereas doping with gadolinium and silver, new more intense peak observed at 290 °C. Irradiation to thermal neutrons revealed single peak around 170 °C for all the phosphors. TL emission spectra and photoluminescence (PL) studies were also carried out on the phosphors. These borate materials are found to be highly sensitive to neutrons and hence can be used for neutron detection. Neutron sensitivity of the material is about ten times that of TLD-600.

  14. Effect of SiO2 nanoparticle doping on electro-optical properties of polymer dispersed liquid crystal lens for smart electronic glasses

    NASA Astrophysics Data System (ADS)

    Kim, Eunju; Liu, Yang; Hong, Sung-Jei; Han, Jeong In

    2015-03-01

    In this paper, SiO2 nanoparticle doped polymer dispersed liquid crystal (PDLC) lenses were made from a mixture of prepolymer, E7 liquid crystal and SiO2 nanoparticles by the polymerization induced phase separation (PIPS) process for smart electronic glasses with auto-shading and auto-focusing functions. Electro-optical properties of doped and undoped samples including transmittance, driving voltage, contrast ratio and slope of the linear region of the transmittance-voltage were measured, compared and analyzed. Driving voltage of SiO2 nanoparticle doped PDLC lenses moderately improved. But the slope of linear region, response time and contrast ratio deteriorated, especially the latter two. It can be assumed that these doping effects were due to the mechanistic change from liquid-gel separation to liquid-liquid separation by the fast heterogeneous nucleation rate caused by the increased nucleation at the surface of SiO2 nanoparticles. The marked deteriorations of falling response time and contrast ratio were due to well defined liquid crystal molecules in LC droplets, which induced slow and imperfect random rearrangement of LC molecules at the off state.

  15. Luminescence characteristics of Li2O-MgO-B2O3 doped with Dy3+ as a solid TL detector

    NASA Astrophysics Data System (ADS)

    Hashim, S.; Mhareb, M. H. A.; Ghoshal, S. K.; Alajerami, Y. S. M.; Bradley, D. A.; Saripan, M. I.; Tamchek, N.; Alzimami, K.

    2015-11-01

    Enhancing the luminescence characteristics of rare earth doped borate glasses is the key issue in achieving an accurate dosimeter. Series of lithium and magnesium oxide modified borate glasses of compositions 20Li2O-(70-x)B2O3-10MgO-xDy2O3, where 0.3?x?1 mol% are prepared using melt-quenching method. Synthesized samples are further activated with different concentration of Dy3+ and subjected to different doses by using a 60Co source. Effects of Dy3+ concentrations on luminescence behavior are examined. XRD patterns confirm the amorphous nature of all samples. A simple glow curve exhibits a peak at 190 °C and optimum intensity for 0.5 mol% of Dy3+ ions. Thermoluminescence (TL) properties including dose response and effective atomic number are determined. A good linearity in the dose response with correlation coefficient ~0.9977 and a tissue equivalent Zeff~8.71 is achieved. The room temperature photoluminescence (PL) spectra of these glasses under 350 nm laser excitations reveal two enhanced peaks centered at 480 nm (blue) and 573 nm (yellow). The mechanism for the TL and PL enhancements are discussed and understood. These attractive luminescence features of prepared glasses may contribute towards the advancement of dosimetry.

  16. Improvement of 1.53 ?m emission and energy transfer of Yb3+/Er3+ co-doped tellurite glass and fiber

    NASA Astrophysics Data System (ADS)

    Zhou, Yaxun; Yin, Dandan; Zheng, Shichao; Peng, Shengxi; Qi, Yawei; Chen, Fen; Yang, Gaobo

    2013-10-01

    To improve the 1.53 ?m band emission of Er3+, the trivalent Yb3+ ions were introduced into the Er3+ single-doped tellurite glass with composition of TeO2-ZnO-La2O3, a potential gain medium for Er3+-doped fiber amplifier (EDFA). The improved effects were investigated from the measured 1.53 ?m band and visible band spontaneous emission spectra together with the calculated 1.53 ?m band stimulated emission (signal gain) spectra under the excitation of 975 nm laser diode (LD). It was found that Yb3+/Er3+ co-doping scheme can remarkably improve the visible band up-conversion and the 1.53 ?m band fluorescence emission intensity, and meanwhile improves the 1.53 ?m band signal gain to some extent, which were attributed to the result of the effective energy transfer of Yb3+:2F5/2 + Er3+:4I15/2 ? Yb3+:2F7/2 + Er3+:4I11/2. The quantitative study of energy transfer mechanism was performed and microscopic energy transfer parameters between the doped rare-earth ions were determined. In addition, the spectroscopic properties of Er3+ were also investigated from the measured absorption spectrum according to the Judd-Ofelt theory, and the structure behavior and thermal stability of the prepared tellurite glass were analyzed based on the X-ray diffraction (XRD) and differential scanning calorimeter (DSC) measurements, respectively.

  17. Optimization of Bi2O3-B2O3-based glass phosphor co-doped with Yb3+ and Nd3+ for optical coherence tomography light source

    NASA Astrophysics Data System (ADS)

    Fuchi, S.; Sakano, A.; Mizutani, R.; Takeda, Y.

    2011-12-01

    We have optimized Yb2O3 concentration, Nd2O3 concentration, and thickness of a Yb3+, Nd3+ co-doped Bi2O3-B2O3-based glass phosphor to achieve a higher output power with a Gaussian-like shaped luminescence for an optical coherence tomography (OCT) light source. A simple model that includes absorption of excitation light, absorption of luminescent light, and luminescence efficiency was used for estimation of the output power. We have estimated from the model that the highest output power was achieved at Yb2O3 concentration of 3%, Nd2O3 concentration of 0.5%, and the thickness of 1.8 mm. This estimation showed a good agreement with the experimental results. For the optimized glass phosphor, we have observed Gaussian-like shaped luminescence, which is important for the OCT light source.

  18. Enhancement of 1.53???m emission in erbium/cerium-doped germanosilicate glass pumped by common 808??nm laser diode.

    PubMed

    Tian, Ying; Wei, Tao; Cai, Muzhi; Chen, Fangze; Wang, Fengchao; Jing, Xufeng; Zhang, Junjie; Zhang, Qinyuan; Xu, Shiqing

    2014-09-20

    Erbium-doped germanosilicate glasses with various cerium ions contents have been prepared. Optical absorption and 1.53 ?m emission spectra were measured to characterize the spectroscopic performances of prepared samples. A detailed study of 1.53 ?m spectroscopic properties was carried out when pumped by an 808 nm laser diode. Moreover, an energy level diagram and an energy transfer mechanism between Er3+ and Ce3+ were proposed to elucidate the enhanced 1.53 ?m fluorescence. It is found that the prepared samples have optimal spectroscopic properties when the Ce3+ concentration is fixed to 0.5 mol. %. High spontaneous radiative transition probability (172.66??s(-1)), large effective emission bandwidth (74 nm), and emission cross section (9.49×10(-21)??cm(2) indicate that 808 nm pumped Er3+/Ce3+ codoped germanosilicate glass might be a suitable material for a broadband optical amplifier. PMID:25322090

  19. Simultaneous generation of the 7.6-eV optical absorption band and F2 molecule in fluorine doped silica glass under annealing

    NASA Astrophysics Data System (ADS)

    Awazu, Koichi; Kawazoe, Hiroshi; Muta, Ken-ichi

    1991-04-01

    We examined chemical state of fluorine doped silica glasses and its thermal behavior. Almost all of the fluorine atoms were found to have the ?SiF structure with Raman spectroscopy. No optical absorption in the region of 3-9 eV was detected in the glass. When the glasses were annealed in a He atmosphere at 1000 °C, absorption bands peaking at 7.6 and 4.3 eV appeared. These two bands are attributed to the ?SiSi? structure and to F2 molecules, respectively. We proposed a thermal decomposition reaction expressed as ?SiF+FSi???SiSi?+F2. The concentrations of the reaction products, ?SiSi? and F2, estimated from the absorption cross sections were equal to each other within the errors of measurements. We also examined the radiation damage with ? ray. The concentration of E' center was almost the same for the same dose in silica glasses having different concentrations of FSi? and ?SiSi?. We suggest that FSi? and ?SiSi? were found to be stable for ?-irradiation at room temperature.

  20. ENVIRONMENTALLY FRIENDLY BORATE-BASED WOOD PRESERVATIVE - PHASE I

    EPA Science Inventory

    This natural organic retention project proposes using lignin from emerging biorefineries to allow borates to be used as wood preservatives for exterior applications exposed to rain. Enhancing the retention of environmentally friendly borates has been the “holy grail...

  1. Transport properties of Pb-doped Bi4Sr3Ca3Cu4Ox semiconducting glasses and glass-ceramic superconductors

    NASA Astrophysics Data System (ADS)

    Chatterjee, S.; Banerjee, S.; Mollah, S.; Chaudhuri, B. K.

    1996-03-01

    Electrical conductivity and thermoelectric power (TEP) of the as-quenched and annealed (at 500 °C for 10 h and 840 °C for 24 h) Bi4-nPbnSr3Ca3Cu4Ox(x=0-1.0) glasses have been measured. The dc conductivity data of the as-quenched and the partially annealed (at 500 °C) glasses can be explained by considering the small-polaron hopping conduction mechanism which is found to change from the nonadiabatic to the adiabatic regime with annealing the glasses at 500 °C. This change over is due to the presence of microcrystals in the partially annealed glasses as observed from x-ray-diffraction and scanning electron microscopic studies. This adiabatic behavior is also visualized even for some as-quenched glasses having a very small amount of the more conducting microcrystalline phase. All the 840 °C annealed glasses are superconductors with Tc between 110 and 115 K. The Seebeck coefficient (S) of the partially annealed glass system is found to be positive and increases linearly with temperature. The S values of the corresponding glass-ceramic superconductors showing broad peaks around Tc. A change over in the values of S from positive (below ˜290 K) to negative (above ˜290 K) indicates the coexistence of both electrons and holes in these superconductors. The TEP data can be fitted with both the two-band model of Forro et al.

    [Solid State Commun. 73, 501 (1990)]
    and the Nagaosa-Lee model
    [Phys. Rev. Lett. 64, 2450 (1990)]
    . Therefore, the bosonic contribution in the transport properties of these superconductors, as suggested by the Nagaosa-Lee model, is supported.

  2. Influence of CuO content on the structure of lithium fluoroborate glasses: Spectral and gamma irradiation studies.

    PubMed

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

    2015-10-01

    Glasses of lithium fluoroborate of the composition LiF 15%-B2O3 85% with increasing CuO as added dopant were prepared and characterized by combined optical and FTIR spectroscopy before and after gamma irradiation. The optical spectrum of the undoped glass reveals strong UV absorption with two distinct peaks at about 235 and 310 nm and with no visible bands. This strong UV absorption is related to the presence of unavoidable trace iron impurity (Fe(3+)) within the materials used for the preparation of this glass. After irradiation, the spectrum of the undoped glass shows a decrease of the intensity of the UV bands together with the resolution of an induced visible broad band centered at about 520 nm. The CuO doped glasses reveal the same UV absorption beside a very broad visible band centered at 780 nm and this band shows extension and splitting to several component peaks with higher CuO contents. Upon gamma irradiation, the spectra of all CuO-doped glasses reveal pronounced decrease of their intensities. The response of irradiation on the studied glasses is correlated with suggested photochemical reactions together with some shielding effect of the copper ions. The observed visible band is related to the presence of copper as distorted octahedral Cu(2+) ions. Infrared absorption spectra of the prepared glasses show repetitive characteristic triangular and tetrahedral borate units similar to that published from alkali or alkaline earth oxides B2O3 glasses. A suggested formation of (BO3/2F) tetrahedral units is advanced through action of LiF on B2O3 and these suggested units showing the same position and number as BO4 tetrahedra. PMID:25989616

  3. Origin of near to middle infrared luminescence and energy transfer process of Er3+/Yb3+co-doped fluorotellurite glasses under different excitations

    NASA Astrophysics Data System (ADS)

    Huang, Feifei; Liu, Xueqiang; Ma, Yaoyao; Kang, Shuai; Hu, Lili; Chen, Danping

    2015-02-01

    We report the near to middle infrared luminescence and energy transfer process of Er3+/Yb3+ co-doped fluorotellurite glasses under 980, 1550 and 800 nm excitations, respectively. Using a 980 nm laser diode pump, enhanced 1.5 and 2.7 ?m emissions from Er3+:I13/2-->4I15/2 and I11/2-->4I13/2 transitions are observed, in which Yb3+ ions can increase pumping efficiency and be used as energy transfer donors. Meanwhile, Yb3+ can also be used as an acceptor and intensive upconversion luminescence of around 1000 nm is achieved from Er3+:I11/2-->4I15/2 and Yb3+: F5/2-->4F7/2 transitions using 1550 nm excitation. In addition, the luminescence properties and variation trendency by 800 nm excitation is similar to that using 1550 nm excitation. The optimum Er3+ and Yb3+ ion ratio is 1:1.5 and excess Yb3+ ions decrease energy transfer efficiency under the two pumpings. These results indicate that Er3+/Yb3+ co-doped fluorotellurite glasses are potential middle- infrared laser materials and may be used to increase the efficiency of the silicon solar cells.

  4. 40 CFR 721.10631 - Mixed metal borate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed metal borate (generic). 721... Substances § 721.10631 Mixed metal borate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal borate (PMN...

  5. 40 CFR 721.10631 - Mixed metal borate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed metal borate (generic). 721... Substances § 721.10631 Mixed metal borate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal borate (PMN...

  6. Green colorants based on energetic azole borates.

    PubMed

    Glück, Johann; Klapötke, Thomas M; Rusan, Magdalena; Stierstorfer, Jörg

    2014-11-24

    The investigation of green-burning boron-based compounds as colorants in pyrotechnic formulations as alternative for barium nitrate, which is a hazard to health and to the environment, is reported. Metal-free and nitrogen-rich dihydrobis(5-aminotetrazolyl)borate salts and dihydrobis(1,3,4-triazolyl)borate salts have been synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry, and vibrational spectroscopy. Their thermal and energetic properties have been determined as well. Several pyrotechnic compositions using selected azolyl borate salts as green colorants were investigated. Formulations with ammonium dinitramide and ammonium nitrate as oxidizers and boron and magnesium as fuels were tested. The burn time, dominant wavelength, spectral purity, luminous intensity, and luminous efficiency as well as the thermal and energetic properties of these compositions were measured. PMID:25284439

  7. Structure and spectroscopic properties of Er3+/Ce3+ co-doped TeO2-Bi2O3-TiO2 glasses modified with various WO3 contents for 1.53 ?m emission

    NASA Astrophysics Data System (ADS)

    Zheng, Shi-chao; Qi, Ya-wei; Peng, Sheng-xi; Yin, Dan-dan; Zhou, Ya-xun; Dai, Shi-xun

    2013-11-01

    The Er3+/Ce3+ co-doped tellurite-based glasses (TeO2-Bi2O3-TiO2) modified with various WO3 contents are prepared using conventional melt-quenching technique. The X-ray diffraction (XRD) patterns and Raman spectra of glass samples are measured to investigate the structures. The absorption spectra, the up-conversion emission spectra, the 1.53 ?m band fluorescence spectra and the lifetime of Er3+:4I13/2 level are measured, and the amplification quality factors of Er3+ are calculated to evaluate the effect of WO3 contents on the 1.53 ?m band spectroscopic properties. With the introduction of WO3, it is found that the prepared tellurite-based glasses maintain the amorphous structure, while the 1.53 ?m band fluorescence intensity of Er3+ is improved evidently, and the fluorescence full width at half maximum (FWHM) is broadened accordingly. In addition, the prepared tellurite-based glass samples have larger bandwidth quality factor than silicate and germanate glasses. The results indicate that the prepared Er3+/Ce3+ co-doped tellurite-based glass with a certain amount of WO3 is an excellent gain medium applied for the 1.53 ?m band Er3+-doped fiber amplifier (EDFA).

  8. Interstitial BiO molecule as a broadband IR luminescence centre in bismuth-doped silica glass

    SciTech Connect

    Sokolov, V O; Plotnichenko, V G; Dianov, Evgenii M

    2011-12-31

    Experimental data on absorption and luminescence in optical fibres with a Bi : SiO{sub 2} glass core are compared to experimentally determined and calculated spectroscopic properties of the BiO molecule. The results suggest that the IR luminescence of Bi : SiO{sub 2} glass is due to interstitial BiO molecules. This assumption is supported by quantum-chemical simulation results for a BiO molecule in a ring interstice of the silica glass network.

  9. Chemical composition and mineralogy of borate from Rio Grande deposit, Uyuni (Bolivia) as raw materials for industrial applications

    NASA Astrophysics Data System (ADS)

    Guillen Vargas, Julio; Arancibia, Jony Roger Hans; Alfonso, Pura; Garcia-Valles, Maite; Parcerisa, David; Martinez, Salvador

    2014-05-01

    Bolivia has large tailings as a result of the historic and present-day Sn mining activity developed extensively in that country. Tailings produced in these mining activities have an appropriate composition to reprocess them and make silicate glass and glass-ceramics, obtaining the valorization of wastes and reducing the visual and chemical impact. Reprocessing the wastes to make glass and glass-ceramics prevents the leaching of heavy metals from those wastes because they are retained in the structure of the glass. Furthermore, an option to increase the economic value of these glasses is the introduction of boron and other additives to produce borosilicate glass. In this study a characterization of the Rio Grande borate deposit for its use in the manufacture of borosilicate glass is presented. Mineralogy was determined by X-ray diffraction (XRD), and Fourier transforms infrared spectroscopy (FTIR); textures were observed by scanning electron microscopy (SEM) and chemical composition was determined by inductively coupled plasma mass spectrometry (ICP-MS). The Rio Grande borate deposit is located in an area of about 50 km2 close to the south of the Salar of Uyuni, in the Río Grande de Lípez Delta. Borates occur in the contact between fluvio-deltaic and lacustrine sediments from water raising the surface by capillarity. The borates crop out in an extent area but towards the west they are covered by fluvio-deltaic sediments, which can be up to 2 m thick. These borates occur as lenses 50-100 m in diameter and layers up to 1 m thick. They usually form brittle nodules with a cotton-ball texture. Chemical composition of the Rio Grande borates is CaO, 11.82-13.83 wt%; Na2O, 13.50-19.35 wt%; K2O, 0.05- 1.04 wt%; MgO, 0.42-1.46 wt%; B2O3, 36.21-42.60 wt%; SiO2, up to 0.53 wt% and SO2, up to 0.60 wt%. Trace elements are low: Sr content is between 151-786 ppm, Al 12-676 ppm, Mn between 1-17 ppm, As 2-10 ppm and Fe between 9-376 ppm. The most abundant borate mineral in this deposit is ulexite (NaCaB5.5H20), halite can reach up to 17 wt% and gypsum up to 1.2 wt.%. Calcite occurs in minor contents. Ulexite exhibits a fibrous morphology with fibers oriented parallel each other. Purity of borates from the Rio Grande deposits makes them suitable for the most restrictive applications. Chemistry of these borates is in accordance with the necessary composition for obtaining borosilicate glasses. Acknowledgements: This work was partly financed by the project AECID: A3/042750/11, and the SGR 2009SGR-00444.

  10. Effect of thermal neutron irradiation on Gd{sup 3+} ions doped in oxyfluoroborate glass: an infra-red study

    SciTech Connect

    Kumar, Akshaya; Rai, S.B.; Rai, D.K

    2003-01-25

    Infrared spectra of oxyfluoroborate glasses of composition (70-x)H{sub 3}BO{sub 3}+20Li{sub 2}CO{sub 3}+xGd{sub 2}O{sub 3}, where x=0, 0.5, 1.0, 3.0 and 5.0 mol%, have been recorded to explore the role of Gd{sup 3+} ions in the structure of the glasses. We concluded that Gd{sup 3+} ion behaves as a glass modifier. The effect of thermal neutron irradiation on the structure of these glasses also has been explored and the changes compared with earlier results on {gamma}-irradiation.

  11. Spectroscopic Evaluation of DNA-Borate Interactions.

    PubMed

    Ozdemir, Ayse; Sarioglu, Omer Faruk; Tekinay, Turgay

    2015-12-01

    We describe the binding characteristics of two natural borates (colemanite and ulexite) to calf thymus DNA by UV-vis absorbance spectroscopy, circular dichroism (CD) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and a competitive DNA binding assay. Our results suggest that colemanite and ulexite interact with calf thymus DNA under a non-intercalative mode of binding and do not alter the secondary structure of the DNA helix. The FT-IR spectroscopy results indicate that the two borates might interact with DNA through sugar-phosphate backbone binding. PMID:25994227

  12. Emission Analysis of RE3+ ( = Nd3+ & Er3+) Doped Bi2O3-B2O3-LiF Glass Systems

    NASA Astrophysics Data System (ADS)

    Rao, K. Srinivasa; Buddhudu, S.

    2011-11-01

    This paper reports on the absorption and emission spectra o of RE3+ ( = Nd3+ or Er3+) doped Bi2O3-B2O3-LiF (Bi-B-LiF) glass system. The absorption spectrum of Nd3+ doped Bi-B-LiF glass has exhibited eight absorption bands at 513 nm, 525 nm, 584 nm, 626 nm, 682 nm, 748 nm, 805 nm and 876 which correspond to the electronic transitions of (4I9/2?4G9/2), (4I9/2?4G9/2, 4G7/2), (4I9/2?4G5/2, 2G7/2), (4I9/2?2H11/2), (4I9/2?4F9/2), (4I9/2?4F5/2, 4S3/2), (4I9/2?4F5/2, 2H9/2) and (4I9/2?4F5/2) respectively. From Nd3+ : Bi-B-LiF glass, three NIR emission bands have been observed at 900 nm, 1075 nm and 1342 nm, which are assigned to the transitions of (4F3/2?4I9/2), (4F3/2?4I11/2) and (4F3/2?4I13/2) respectively with an excitation at 514.5 nm (Ar+ ion laser). The Er3+ : Bi-B-LiF glass has revealed six absorption bands at 489 nm, 522 nm, 653 nm, 800 nm, 973 nm and 1531 nm which are labeled to the transitions of (4I15/2?4F7/2), (4I15/2?2H11/2, 4G11/2), (4I15/2?4F9/2), (4I15/2?4I7/2), (4I15/2?4I11/2), and (4I15/2?4I13/2) respectively. From the Er3+: Bi-B-LiF glass, an NIR emission at 1540 nm (4I13/2?4I15/2), has been observed with an excitation at 514.5 nm (Ar+ ion laser).

  13. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C. E-mail: unnikrishnan.vk@manipal.edu; Sonavane, M. S.; Yeotikar, R. G.; Shah, M. L.; Gupta, G. P.; Suri, B. M.

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×10{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  14. Enhanced 2.7 ?m emission from Er3+ doped oxyfluoride tellurite glasses for a diode-pump mid-infrared laser

    NASA Astrophysics Data System (ADS)

    Zhang, F. F.; Zhang, W. J.; Yuan, J.; Chen, D. D.; Qian, Q.; Zhang, Q. Y.

    2014-04-01

    The influence of fluoride and shielding gas (O2 or Ar) on the physical and spectroscopic properties of Er3+ doped TeO2-ZnO-ZnF2 glass system is investigated. The larger electronegativity of F than O accounts for the gradual decrease of refractive index, density, and J-O parameters with increasing ZnF2. An analysis on Fourier transform infrared transmission spectra reveals that the absorption coefficient of OH- around 3 ?m as low as 0.247 cm-1 can be achieved when 30 mol% ZnF2 containing sample is treated with Ar gas during glass melting process. The reduction of OH- groups combined with the low multiphonon relaxation rate (207 s-1) contributes to the enhanced emissions at 1.5 and 2.7 ?m, along with prolonged lifetimes of 4I11/2 and 4I13/2 levels. A high branching ratio (17.95%) corresponding to the Er3+: 4I11/2 ? 4I13/2 transition, the large absorption and emission cross section (0.44 × 10-20 cm2 and 0.45 × 10-20 cm2), and good gain cross section demonstrate that oxyfluoride tellurite glass could be a promising material for a diode-pump 2.7 ?m fiber laser.

  15. Bifunction in Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} glasses prepared by aerodynamic levitation method

    SciTech Connect

    Zhang, Minghui; Yu, Jianding; Pan, Xiuhong; Cheng, Yuxing; Liu, Yan

    2013-11-15

    Graphical abstract: - Highlights: • Novel BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} based glasses have been prepared by aerodynamic levitation. • The obtained glasses show high thermal stability with T{sub g} = 763.3 °C. • Er{sup 3+}/Yb{sup 3+} co-doped glasses show strong upconversion based on a two-photon process. • Red emission is stronger than green emissions for EBT by high Yb{sup 3+} concentration. • Magnetic ions are paramagnetic and the distribution is homogeneous in the glasses. - Abstract: Novel Er{sup 3+}/Yb{sup 3+} co-doped BaTi{sub 2}O{sub 5}–Gd{sub 2}O{sub 3} spherical glasses have been fabricated by aerodynamic levitation method. The thermal stability, upconversion luminescence, and magnetic properties of the present glass have been studied. The glasses show high thermal stability with 763.3 °C of the onset temperature of the glass transition. Red and green emissions centered at 671 nm, 548 nm and 535 nm are obtained at 980 nm excitation. The upconversion is based on a two-photon process by energy transfer, excited-state absorption, and energy back transfer. Yb{sup 3+} ions are more than Er{sup 3+} ions in the glass, resulting in efficient energy back transfer from Er{sup 3+} to Yb{sup 3+}. So the red emission is stronger than the green emissions. Magnetization curves indicate that magnetic rare earth ions are paramagnetic and the distribution is homogeneous and random in the glass matrix. Aerodynamic levitation method is an efficient way to prepare glasses with homogeneous rare earth ions.

  16. A crystal-chemical classification of borate structures with emphasis on hydrated borates

    USGS Publications Warehouse

    Christ, C.L.; Clark, J.R.

    1977-01-01

    The rules governing formation of hydrated borate polyanions that were proposed by C.L. Christ in 1960 are critically reviewed and new rules added on the basis of recent crystal structure determinations. Principles and classifications previously published by others are also critically reviewed briefly. The fundamental building blocks from which borate polyanions can be constructed are defined on the basis of the number n of boron atoms, and the fully hydrated polyanions are illustrated. Known structures are grouped accordingly, and a shorthand notation using n and symbols ?? = triangle, T = tetrahedron is introduced so that the polyanions can be easily characterized. For example, 3:??+2T describes [B3O3(OH)5]2-. Correct structural formulas are assigned borates with known structures whereas borates of unknown structure are grouped separately. ?? 1977 Springer-Verlag.

  17. Local structure around rare-earth ions in B{sub 2}O{sub 3} glass at high pressure

    SciTech Connect

    Funabiki, Fuji; Matsuishi, Satoru; Hosono, Hideo; Research Center for Strategic Materials, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, 226-8503; Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, 226-8503

    2013-06-14

    Melt quenching of B{sub 2}O{sub 3} with less than 25 mol. % rare-earth oxide (RE{sub 2}O{sub 3}) at ambient pressure results in a milky white glass because of liquid-liquid phase separation into B{sub 2}O{sub 3} and RE{sub 2}O{sub 3}{center_dot}3B{sub 2}O phases. In contrast, we have found that melt quenching under GPa-order pressure realizes a transparent RE-doped B{sub 2}O{sub 3} glass. This study investigates the local structure around the RE ions in the B{sub 2}O{sub 3} glass prepared at 3 GPa using optical measurements and electron-spin-echo envelope modulation spectroscopy. It is shown that the RE-rich microparticles disappear and the RE ions are isolated from each other in a highly symmetric crystal field formed by triangular and tetrahedral boron units. This result is consistent with that extrapolated from the data for RE-doped sodium borate glasses.

  18. Borate in mummification salts and bones from Pharaonic Egypt.

    PubMed

    Kaup, Yoka; Schmid, Mirjam; Middleton, Andrew; Weser, Ulrich

    2003-03-01

    Mummification processes in Pharaonic Egypt were successful using sodium salts. Quite frequently sodium concentrations in mummified bones ranged from 300 to 4000 micromol/g. In the search for an effective inorganic conservation compound our choice fell on boric acid. The possible presence of borate in mummification salts used in Pharaonic Egypt was of special interest both historically and biochemically. In two salt samples, one from the embalming material of Tutankhamen (18th dynasty, 1336-1327 BC) and the second from Deir el-Bahari (25th dynasty, 700-600 BC) borate was found, amounting to 2.1+/-0.2 and 3.9+/-0.1 micromol/g, respectively. In five of the examined bone fragments from the Junker excavation at Giza (Old Kingdom) similar borate concentrations i.e., 1.2 micromol borate/g bone were seen. It must be emphasized that the usual borate content of contemporary autopsy is far below the detection limit. The elevated borate content in both mummification salt and ancient bone samples support the suggestion that borate-containing salt had been used. There is a striking correlation of both borate concentration and alkaline phosphatase activity. When both sodium salts and borate were essentially absent no activity at all was detectable. With increasing borate concentrations the enzyme activity rises significantly. Attributable to the distinct biochemistry of the tetrahydroxyborate anion it was of interest whether or not borate may stabilize alkaline phosphatase, an important and richly abundant bone enzyme. This enzyme was chosen, as it is known to survive more than 4000 years of mummification. In the presence of borate oligomeric species of this zinc-magnesium-glycoprotein at 400,000 Da became detectable. Attributable to this borate-dependent stabilization of the enzyme molecule a significant temperature resistant increase of the enzymic activity was measured in the presence of up to 2.5 mM borate. PMID:12628701

  19. Passive safety injection system using borated water

    DOEpatents

    Conway, Lawrence E. (Allegheny, PA); Schulz, Terry L. (Westmoreland, PA)

    1993-01-01

    A passive safety injection system relies on differences in water density to induce natural circulatory flow patterns which help maintain prescribed concentrations of boric acid in borated water, and prevents boron from accumulating in the reactor vessel and possibly preventing heat transfer.

  20. Infrared luminescence in Bi-doped Ge-S and As-Ge-S chalcogenide glasses and fibers

    E-print Network

    Plotnichenko, V G; Sokolov, V O; Sukhanov, M V; Velmuzhov, A P; Churbanov, M F; Dianov, E M

    2014-01-01

    Experimental and theoretical studies of spectral properties of chalcogenide Ge-S and As-Ge-S glasses and fibers are performed. A broad infrared (IR) luminescence band which covers the 1.2-2.3~$\\mu$m range with a lifetime about 6~$\\mu$s is discovered. Similar luminescence is also present in optical fibers drawn from these glasses. Arsenic addition to Ge-S glass significantly enhances both its resistance to crystallization and the intensity of the luminescence. Computer modeling of Bi-related centers shows that interstitial Bi$^+$ ions adjacent to negatively charged S vacancies are most likely responsible for the IR luminescence.

  1. Extraction of heavy metal ions from waste colored glass through phase separation.

    PubMed

    Chen, Danping; Masui, Hirotsugu; Miyoshi, Hiroshi; Akai, Tomoko; Yazawa, Tetsuo

    2006-01-01

    A new method utilizing phase separation phenomena for the extraction of heavy metal ions used as colorants in colored glass is proposed. Colored soda-lime-silica glass containing Co or Cr as a colorant was remelted with B2O3 to yield soda-lime-borosilicate glass. The soda-lime-borosilicate glass thus obtained was leached in 1M nitric acid at 90 degrees C to dissolve the borate phase. All cations (Na, Ca, Cr and Co) concentrated in the borate phase are successfully leached out with the dissolution of the borate phase, when the amount of the B2O3 added to the glass and heat treatment conditions are properly chosen. Porous silicate glass powders with high SiO2 purity are obtained as the result of the leaching. Porous glass can also be formed as bulk material by controlling the composition of additives during the remelting. PMID:16307875

  2. Comparative studies between theoretical and experimental of elastic properties and irradiation effects of soda lime glasses doped with neodymium oxide

    NASA Astrophysics Data System (ADS)

    Bootjomchai, C.

    2015-05-01

    A comparative studies on the theoretical and experimental values of elastic moduli of (90 - x) RWG -(10)Na2O -(x)Nd2O3 glass system, where RWG is recycled window glass and x is 0.001, 0.01, 0.1 and 1 mol%, was investigated. The radiation effects on structural properties and elastic moduli were evaluated by measuring the ultrasonic velocities. In addition, the FTIR spectra were measured to investigate the effects of irradiation on the structure of the glass. Moreover, the theoretical bond compression model was used to confirm the obtained results from the experiments. The results show that evidently changes in the structure of the glass depend on the concentration of the neodymium oxide and gamma irradiation. Furthermore, the experimental elastic moduli are in good agreement with the theoretical values.

  3. Laser-induced radial birefringence and spin-to-orbital optical angular momentum conversion in silver-doped glasses

    E-print Network

    Marrucci, Lorenzo

    manufacturing and flexible properties. Different techniques have been demonstrated to control the silver cluster by the well known Agþ /Naþ ion exchange technique.11,14,15 Soda-lime glass slides of dimensions 39 Â 25 Â 0

  4. Mesoporous bioactive glass doped-poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) composite scaffolds with 3-dimensionally hierarchical pore networks for bone regeneration.

    PubMed

    Yang, Shengbing; Wang, Jing; Tang, Liangji; Ao, Haiyong; Tan, Honglue; Tang, Tingting; Liu, Changsheng

    2014-04-01

    Scaffolds play a critical role in bone tissue engineering. Composite scaffolds made of biodegradable polymers and bioactive inorganic compounds have demonstrated superior properties in bone defect repair. In this study, highly bioactive, resorbable poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)-based scaffolds were prepared using combinational 3-dimensional (3D) printing and surface-doping protocol. Structural and morphological characterization of the composite scaffolds demonstrated the homogenous surface-coating of mesoporous bioactive glass (MBG) throughout their porous framework. These hierarchical scaffolds showed bioactivity superior to that of scaffolds made of pure PHBHHx. MBG coating appeared to provide a better environment for human mesenchymal stem cells (hMSCs) attachment, activity, and osteogenic differentiation. Our study indicates that MBG-coated PHBHHx (PHBM) scaffolds may be excellent candidates for use in bone tissue engineering. PMID:24441182

  5. Transparent cobalt doped MgO-Ga{sub 2}O{sub 3}-SiO{sub 2} nano-glass-ceramic composites

    SciTech Connect

    Duan, X. L.; Yuan, D. R.; Yu, F. P.; Wang, L. H.

    2006-10-30

    Transparent cobalt doped MgO-Ga{sub 2}O{sub 3}-SiO{sub 2} nano-glass-ceramic composites were prepared from Si, Ga, Mg, and Co molecular precursors by a sol-gel method. X-ray diffraction patterns and transmission electron microscopy showed that the resulting material is composed of an amorphous silicate network that encloses nanocrystalline MgGa{sub 2}O{sub 4} particles. Analysis of the absorption and luminescence properties indicates that Co ions are, at least partially, trapped in the crystalline phase and located in tetrahedral sites in MgGa{sub 2}O{sub 4} nanocrystals. The absorption section was calculated to be 1.15x10{sup -19} cm{sup 2}.

  6. Mid-infrared fluorescence of Y2O3 and Nb2O5 modified germanate glasses doped with Er3+ pumped by 808 nm LD

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Chen, Fangze; Jing, Xufeng; Tian, Ying; Wang, Fengchao; Xu, Shiqing

    2014-06-01

    Er3+ doped germanate glasses modified by Y2O3 and Nb2O5 have been prepared. A detailed discussion of J-O parameters has been carried out based on absorption spectra and Judd-Ofelt theory. Mid-infrared transmittance spectra and 2.7 ?m emission properties have been investigated. To understand 2.7 ?m fluorescence behaviors, 1.53 ?m emission spectra, radiative lifetimes, non-radiative relaxation rate constants of the 4I11/2 ? 4I13/2 transition and energy transfer coefficients of 4I13/2 level have been obtained and discussed. As a result, the investigated samples with excellent spectroscopic properties might be appropriate optical materials for mid-infrared laser and amplifier applications.

  7. Control of Ag nanoparticle distribution influencing bioactive and antibacterial properties of Ag-doped mesoporous bioactive glass particles prepared by spray pyrolysis.

    PubMed

    Shih, Shao-Ju; Tzeng, Wei-Lung; Jatnika, Rifqi; Shih, Chi-Jen; Borisenko, Konstantin B

    2015-05-01

    Mesoporous bioactive glasses (MBGs) have become important bone implant materials because of their high specific surface area resulting in high bioactivity. Doping MBGs with Ag removes one of the remaining challenges to their applications, namely their lack of intrinsic antibacterial properties. In present work we demonstrate that Ag-doped MBGs can be prepared in one-step spray pyrolysis (SP) process. The SP preparation method offers the advantages of short processing times and continuous production over the sol-gel method previously used to prepare MBGs. Using scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction we demonstrate that the synthesized MBG particles have amorphous structure with nanocrystalline Ag inclusions. The scanning transmission electron microscopy-X-ray energy dispersive spectrometry of cross-sectional samples shows that the distribution of the Ag dopant nanoparticles within MBGs can be controlled by using the appropriate formulation of the precursors. The distribution of the Ag dopant nanoparticles within the MBG particles was found to affect their surface areas, bioactivities and antibacterial properties. Based on the observations, we propose a mechanism describing MBG particle formation and controlling dopant distribution. PMID:25171327

  8. Fabrication and photocatalytic characterizations of ordered nanoporous X-doped (X = N, C, S, Ru, Te, and Si) TiO2/Al2O3 films on ITO/glass.

    PubMed

    Chu, Song-Zhu; Inoue, Satoru; Wada, Kenji; Li, Di; Suzuki, Jun

    2005-08-16

    Transparent, ordered nanoporous TiO2/Al2O3 composite films doped with metal elements (Ru, Si, and Te) and nonmetal elements (N, C, and S) were fabricated by successive anodization and sol-gel process directly on glass substrates covered with a tin-doped indium oxide (ITO) film. The doping of ruthenium, nitrogen, carbon, and sulfur in TiO2 exhibited an enhanced effect on the absorbance, while the doping of silicon and tellurium showed little effect. Particularly, the N- and Ru-doped TiO2/Al2O3 films on ITO/glass developed an enhanced absorption red shift of 580 nm (-N) and 500 nm (-Ru). The nanoporous TiO2/Al2O3 composite film exhibited the highest photocatalytic activity in decomposing acetaldehyde under ultraviolet-light irradiation, with a value of 13 times in initial reaction rate or 7.8 times in quantum yield higher than a commercially available TiO2 material, Degussa P25. The ultraviolet-light photocatalytic activities of nanoporous TiO2/Al2O3 films were enhanced by the doping of nitrogen, carbon, and sulfur but slightly weakened by the doping of ruthenium, silicon, and tellurium. Particularly, the nanoporous N-doped TiO2/Al2O3 films exhibited effective photocatalytic activity on ultraviolet light decomposition of a highly toxic dioxin, HpCDD, and gave the highest decomposition rate of approximately 95% (via 7 h of irradiation) for the specimen with a dopant content of 1.7 wt % nitrogen. PMID:16089417

  9. Evaluation of the {sup 4}I{sub 11/2} terminal level lifetime for several neodymium-doped laser crystals and glasses

    SciTech Connect

    Bibeau, C.

    1995-04-25

    All models of lasing action require knowledge of the physical parameters involved, of which many can be measured or estimated. The value of the terminal level lifetime is an important parameter in modeling many high power laser systems since the terminal level lifetime can have a substantial impact on the extraction efficiency of the system. However, the values of the terminal level lifetimes for a number of important laser materials such as ND:YAG and ND:YLF are not well known. The terminal level lifetime, a measure of the time it takes for the population to drain out of the terminal (lower) lasing level, has values that can range from picoseconds to microseconds depending on the host medium, thus making it difficult to construct one definitive experiment for all materials. Until recently, many of the direct measurements of the terminal level lifetime employed complex energy extraction or gain recovery methods coupled with a numerical model which often resulted in large uncertainties in the measured lifetimes. In this report we demonstrate a novel and more accurate approach which employs a pump-probe technique to measure the terminal level lifetime of 16 neodymium-doped materials. An alternative yet indirect method, which is based on the ``Energy Gap Law,`` is to measure the nonradiative lifetime of another transition which has the same energy gap as the transition of the terminal level lifetime. Employing this simpler approach, we measured the lifetime for 30 neodymium-doped materials. We show for the first time a direct comparison between the two methods and determine that the indirect method can be used to infer the terminal level lifetime within a factor of two for most neodymium-doped glasses and crystals.

  10. Glass microspheres for medical applications

    NASA Astrophysics Data System (ADS)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in <1 week, without causing any detectable joint damage. The combination of dysprosium lithium borate glass microspheres and EDTA chelation therapy provides an unique "tool" for the medical community, which can deliver a large dose (>100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ?200 m2/g, a pore size of ?30 nm, and a nominal crushing strength of ?10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass microspheres containing 3.7 GBq of 186Re and 8.5 GBq of 188Re could be used to deliver a 100 Gy dose to a cancerous tumor, while limiting the total body dose caused by rhenium dissolution to approximately 1 mGy.

  11. Optical and structural investigation of Dy3+-Nd3+ co-doped in magnesium lead borosilicate glasses.

    PubMed

    Rao, T G V M; Rupesh Kumar, A; Neeraja, K; Veeraiah, N; Rami Reddy, M

    2014-01-24

    MgO-PbO-B2O3-SiO2-Nd2O3-Dy2O3 glasses are prepared by melt-quenching technique. The samples are characterized by X-ray diffraction (XRD), optical absorption, luminescence and Fourier transform infrared (FT-IR) spectral studied. XRD analysis evidently indicates that the prepared samples are fully amorphous nature. From the optical absorption spectra, the bonding environment surrounding the Dy(3+) and their energy level scheme in glass network is analyzed. Enhancement of Dy(3+) emission by non-radiative energy transfers from Nd(3+) has been observed here. The samples emits intensive bluish yellow color from the (4)F9/2?(6)H15/2, (6)H13/2 transition of Dy(3+) ions in these glasses which are nearer to white light and it is also supported by the chromaticity color coordinates. The FT-IR spectra reveal that network connectivity is increased with replacement of bonds B-O-B, Si-O-Si by more resistant B-O-Si bonds with gradually increasing the content of Dy(3+) ions in the glass network. Along with spectroscopic parameters some physical parameters like density, refractive index etc. are measured for the glasses. PMID:24121603

  12. The effects of glass doping, temperature and time on the morphology, composition, and iron redox of spinel crystals

    SciTech Connect

    Matyas, Josef; Amonette, James E.; Kukkadapu, Ravi K.; Schreiber, Daniel K.; Kruger, Albert A.

    2014-10-31

    Precipitation of large crystals/agglomerates of spinel and their accumulation in the pour spout riser of a Joule-heated ceramic melter during idling can plug the melter and prevent pouring of molten glass into canisters. Thus, there is a need to understand the effects of spinel-forming components, temperature, and time on the growth of crystals in connection with an accumulation rate. In our study, crystals of spinel [Fe, Ni, Mn, Zn, Sn][Fe, Cr]?O? were precipitated from simulated high-level waste borosilicate glasses containing different concentrations of Ni, Fe, and Cr by heat treating at 850 and 900°C for different times. These crystals were extracted from the glasses and analyzed with scanning electron microscopy and image analysis for size and shape, with inductively coupled plasma-atomic emission spectroscopy and atom probe tomography for concentration of spinel-forming components, and with wet colorimetry and Mössbauer spectroscopy for Fe²?/Fetotal ratio. High concentrations of Ni, Fe, and Cr in glasses resulted in the precipitation of crystals larger than 100 µm in just two days. Crystals were a solid solution of NiFe?O?, NiCr?O?, and -Fe?O? (identified only in the high-Ni-Fe glass) and also contained small concentrations of less than 1 at% of Li, Mg, Mn, and Al.

  13. Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}

    SciTech Connect

    Hu Zhongjian; Wang Yuansheng . E-mail: yswang@fjirsm.ac.cn; Ma En; Bao Feng; Yu Yunlong; Chen Daqin

    2006-01-05

    Transparent oxyfluoride glass ceramics with composition of 45SiO{sub 2}-25Al{sub 2}O{sub 3}-5CaCO{sub 3}-10NaF-15CaF{sub 2}-0.5ErF{sub 3} (in mol%) were developed through controlled crystallization of melt-quenched glass. Non-isothermal crystallization kinetics investigation showed that the average apparent activation energy E {sub a} and Avrami exponent n are about 283 kJ/mol and 2.22, respectively, indicating the crystallization a three dimensional crystal growth process controlled by the diffusion with a decreasing nucleation rate. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) observation revealed the precipitation of CaF{sub 2} crystallites sized about 15 nm among the glass matrix after heat-treatment at 650 deg. C for 2 h. For as-made glass, no upconversion signals were detected when excited with a 30 mW diode laser at 980 nm, while strong upconversion emissions at 545, 660 and 800 nm were obtained for transparent glass ceramic under similar excitation conditio000.

  14. Spectral analysis of Cu(2+): B(2)O(3)--ZnO--PbO glasses.

    PubMed

    Lakshminarayana, G; Buddhudu, S

    2005-11-01

    A new series of heavy metal oxide (PbO) based zinc borate glasses in the chemical composition of (95-x)B(2)O(3)-5ZnO-xPbO (x=10, 15, 20, 25, 30, 35, 40, 45 and 50 mol%) have been prepared to verify their UV filtering performance. Both direct and indirect optical band gaps (E(opt)) have been evaluated for these glasses. For a reference glass of 45B(2)O(3)-5ZnO-50PbO, refractive indices at different wavelengths are measured and found the results satisfactorily correlated with the theoretical data upon the computation of Cauchy's constants of A=1.766029949, B=159531.024 nm(2) and C=-1.078 x 10(10) nm(4). Measurements concerning X-ray diffraction (XRD), FT-IR, differential scanning colorimeter (DSC) profiles have been carried out for this glass. The FT-IR profile has revealed that the glass has both BO(3) and BO(4) units. From DSC thermogram, glass transition temperature (T(g)), crystallization temperature (T(c)) and melting temperature (T(m)) have been located and from them, other related parameters of the glass have also been calculated. Visible absorption spectra of 45B(2)O(3)-5ZnO-(50-x)PbO-xCuO (x=0. 1, 0.2, 0.5 and 1.0 mol%) have revealed two absorption bands at around 400 nm ((2)B(1g)-->(2)E(g)) and 780 nm ((2)B(1g)-->(2)B(2g)) of Cu(2+) ions, respectively. Emission bands at 422 and 512 nm are found for the 1 mol % CuO doped glass with excitations at 306 and 332 nm. PMID:16257737

  15. Effects of UV cure on glass structure and fracture properties of nanoporous carbon-doped oxide thin films

    SciTech Connect

    Gage, David M.; Dauskardt, Reinhold H.; Stebbins, Jonathan F.; Peng Luming; Cui Zhenjiang; Al-Bayati, Amir; MacWilliams, Kenneth P.; M'Saad, Hichem

    2008-08-15

    The effects of UV radiation curing on the glass structure and fracture properties were examined for a class of nanoporous organosilicate low dielectric constant films. A detailed characterization by nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy showed significant changes in the glass structure with increasing curing time, marked by the removal of terminal organic groups and increased network-forming bonds following the initial removal of porogen material. The higher degree of film connectivity brought about by an increased cure duration is demonstrated to significantly enhance adhesive fracture properties and to moderately improve cohesive fracture resistance. Explanations for the enhanced fracture behavior are considered in terms of the glass structure. The important role of crack path selection during adhesive and cohesive fracture processes is used to rationalize the observed behavior.

  16. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Karaya and sodium borate with or without acacia denture...Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture... (a) Identification. A karaya and sodium borate with or without acacia...

  17. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 false Karaya and sodium borate with or without acacia denture...Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture... (a) Identification. A karaya and sodium borate with or without acacia...

  18. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Karaya and sodium borate with or without acacia denture...Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture... (a) Identification. A karaya and sodium borate with or without acacia...

  19. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 false Karaya and sodium borate with or without acacia denture...Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture... (a) Identification. A karaya and sodium borate with or without acacia...

  20. 40 CFR 721.10627 - Yttrium borate phosphate vanadate with europium and additional dopants (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Yttrium borate phosphate vanadate with europium...Chemical Substances § 721.10627 Yttrium borate phosphate vanadate with europium...chemical substance identified generically as yttrium borate phosphate vanadate with...