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. Optical properties of Eu 3+-doped zinc borate glasses

    Microsoft Academic Search

    A. Ivankov; J. Seekamp; W. Bauhofer

    2006-01-01

    Photoluminescence, absorption and optical excitation spectra of undoped and Eu3+-doped binary zinc borate glasses of varied composition prepared by the melt quenching technique in air atmosphere were investigated. From photoluminescence measurements it was found that growing Eu3+ concentration leads to gradual disappearance of the broadband glass emission in the near-UV spectral range, while the red Eu3+ emission at 613nm shows

  3. Spectral down-conversion in Sm-doped borate glasses for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Dyrba, Marcel; Miclea, Paul T.; Schweizer, Stefan

    2010-05-01

    Borate glasses and borate glass ceramics are good candidates as a matrix material for fluorescent ions like samarium. The chosen network modifier influences the fluorescence efficiency of the incorporated rare earth ion. Sm3+-doped lithium, sodium, barium and lead borate glasses were examined with respect to their fluorescence properties and potential use as a down-converting top layer of a solar cell.

  4. Infrared spectra of zinc doped lead borate glasses

    Microsoft Academic Search

    S. G. Motke; S. P. Yawale; S. S. Yawale

    2002-01-01

    The infrared spectra of zinc-doped lead borate glasses (10–30 mol% ZnO) were measured over a continuous spectral range (400–4000\\u000a cm?1) in an attempt to study their structure systematically. No boroxol ring formation was observed in the structure of these\\u000a glasses. The formation of Zn in tetrahedral coordination was not observed. The conversion of three-fold to four-fold coordinated\\u000a boron took place.

  5. Optical properties of Dy3+ doped bismuth zinc borate glass and glass ceramics

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    Dy3+ doped bismuth zinc borate transparent glasses were prepared by melt quenching technique and these glasses were used precursor to obtain transparent glass ceramics by heat treatment method. XRD pattern of the glass ceramic shows the formation of the ?-BiB3O6 and Bi2ZnOB2O6 phases. The visible emission intensity of the glass ceramics is stronger than the glass. This can be due to the formation of nano nonlinear optical crystallites in glass matrix.

  6. Undoped and calcium doped borate glass system for thermoluminescent dosimeter

    Microsoft Academic Search

    S. S. Rojas; K. Yukimitu; A. S. S. de Camargo; L. A. O. Nunes; A. C. Hernandes

    2006-01-01

    Borate glasses present an absorption coefficient very close to that of human tissue. This fact makes some borates ideal materials to develop medical and environmental dosimeters. Glass compositions with calcium tetraborate (CaB4O7) and calcium metaborate (CaB2O4), such as the xCaB4O7?(100?x)CaB2O4 system (0?x?100wt%) were obtained by the traditional melting\\/quenching method. A phenomenon widely known as the ‘boron anomaly’ was observed in

  7. Spectroscopic investigation of zinc borate glasses doped with trivalent europium ions

    Microsoft Academic Search

    M. Bettinelli; A. Speghini; M. Ferrari; M. Montagna

    1996-01-01

    4ZnO · 3B2O3 glasses undoped and doped with 0.5–2.5% Eu3+ were studied using absorption, emission and excitation spectroscopies, fluorescence line narrowing, Raman scattering and lifetime measurements. The vibrational spectra of the undoped and doped glasses are very similar and indicate the presence of borate groups already observed in binary metaborate glasses. The Judd-Ofelt parameters and the asymmetry ratio derived from

  8. Optical characterization of Eu 3+ and Tb 3+ ions doped zinc lead borate glasses

    Microsoft Academic Search

    A. Thulasiramudu; S. Buddhudu

    2007-01-01

    This paper reports on the spectral analysis of Eu3+ or Tb3+ ions (0.5mol%) doped heavy metal oxide (HMO) based zinc lead borate glasses from the measurement of their absorption, emission spectra and also different physical properties. From the XRD, DSC profiles, the glass nature and glass thermal properties have been studied. The measured emission spectrum of Eu3+ glass has revealed

  9. Elastic properties of Li+ doped lead zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2014-04-01

    Glasses in the system 0.25PbO-(0.25-x) ZnO-0.5B2O3-xLi2O have been prepared by the melt quenching technique. Elastic properties, DSC studies have been employed to study the role of Li2O in the present glass system. Elastic properties and Debye temperature have been determined using pulsed echo ultrasonic interferometer operating at 10MHz. Sound velocities Vl, Vt and elastic moduli decrease up to 5 mol% and then gradually increase with increase in Li2O concentration. Debye temperature and the glass transition temperature decreases with increase in Li2O. Densities remains almost constant up to 15 mol% Li2O concentration and increases monotonically while the molar volume decreases with the increase of Li2O concentration. The results are discussed in view of the borate structural network and dual role of Zn and Pb in these glasses.

  10. Fluorescence properties of Eu 3+ ions doped borate and fluoroborate glasses containing lithium, zinc and lead

    NASA Astrophysics Data System (ADS)

    Venkatramu, V.; Babu, P.; Jayasankar, C. K.

    2006-02-01

    The influence of glass composition on the fluorescence properties of Eu 3+ ions doped borate and fluoroborate glasses modified with Li +, Zn 2+ and Pb 2+ cations have been investigated. The magnitude of splittings of 7F 1 levels are analyzed using crystal-field (CF) analysis. The relative intensities of 5D 0 ? 7F 2 to 5D 0 ? 7F 1 transitions, crystal-field strength parameters and decay times of the 5D 0 level have been determined and are found to be lower for Pb based glasses than those of Zn/Li based glasses. The lifetimes of 5D 0 level are found to increase when borate glasses are modified with pure fluorides than with oxides and oxyfluorides. The fluorescence decay of 5D 0 level fits perfect single exponential in the Eu 3+:glass systems studied which indicates the absence of energy transfer between Eu 3+ ions in these glasses.

  11. Fluorescence properties of Eu3+ ions doped borate and fluoroborate glasses containing lithium, zinc and lead.

    PubMed

    Venkatramu, V; Babu, P; Jayasankar, C K

    2006-02-01

    The influence of glass composition on the fluorescence properties of Eu3+ ions doped borate and fluoroborate glasses modified with Li+, Zn2+ and Pb2+ cations have been investigated. The magnitude of splittings of 7F1 levels are analyzed using crystal-field (CF) analysis. The relative intensities of 5D0 --> 7F2 to 5D0 --> 7F1 transitions, crystal-field strength parameters and decay times of the 5D0 level have been determined and are found to be lower for Pb based glasses than those of Zn/Li based glasses. The lifetimes of 5D0 level are found to increase when borate glasses are modified with pure fluorides than with oxides and oxyfluorides. The fluorescence decay of 5D0 level fits perfect single exponential in the Eu3+:glass systems studied which indicates the absence of energy transfer between Eu3+ ions in these glasses. PMID:15979397

  12. 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).

  13. Physical and optical characterization of Er3+ doped lead-zinc-borate glass.

    PubMed

    Sooraj Hussain, N; Cardoso, P J; Hungerford, G; Gomes, M J M; Ali, Nasar; Santos, J D; Buddhudu, S

    2009-06-01

    This paper reports on the systematic optical characterization of Er3+ (1.0%) doped lead-zinc-borate glass from the measured absorption, luminescence and fluorescence lifetime decay curve profiles. By the application of the Judd-Ofelt theory, spectral intensities of the absorption bands have been analysed and these absorption results have been used in evaluating the luminescence properties of the Er3+ doped lead-zinc-borate glass. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have been computed. Based on the measured glass density, and refractive indices, other related physical parameters have also been evaluated. Further, the structural and morphology of the glass material have also been investigated from X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. PMID:19504881

  14. Thermoluminescent and optical absorption properties of neodymium doped yttrium aluminoborate and yttrium calcium borate glasses

    Microsoft Academic Search

    E. M. Yoshimura; C. N. Santos; A. Ibanez; A. C. Hernandes

    2009-01-01

    Neodymium doped yttrium aluminoborate and yttrium calcium borate glasses were prepared by the conventional melting-quenching technique with neodymium concentration varying from 0.10 to 1.0mol%. The obtained glasses present a wide transparency in the UV–visible region (till 240nm). The thermoluminescent (TL) emission of beta-irradiated samples was measured, showing a broad peak at ?240°C with intensities related to the Nd3+ content, for

  15. 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.

  16. Thermoluminescent and optical absorption properties of neodymium doped yttrium aluminoborate and yttrium calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Yoshimura, E. M.; Santos, C. N.; Ibanez, A.; Hernandes, A. C.

    2009-04-01

    Neodymium doped yttrium aluminoborate and yttrium calcium borate glasses were prepared by the conventional melting-quenching technique with neodymium concentration varying from 0.10 to 1.0 mol%. The obtained glasses present a wide transparency in the UV-visible region (till 240 nm). The thermoluminescent (TL) emission of beta-irradiated samples was measured, showing a broad peak at ˜240 °C with intensities related to the Nd 3+ content, for both glasses. Calcium borate glass samples are about one order of magnitude less luminescent than the aluminoborate glasses. Probably the presence of Ca 2+, instead of Al 3+ and Y 3+ in the matrix, inhibits the production of the intrinsic hole centers, connected to boron and oxygen, known in the literature to act as luminescent centers in TL emission of borate glasses. We suggest that Nd 3+ ions act as electron trapping centers in both glass matrices, as they modify the temperature of emission and the light intensity. Also, the Nd:YAlB glass can be used as a dosimeter in various applications, including radiotherapy, but the sensitivity of this material to neutron should be checked.

  17. Optical Properties of Eu3+ Doped Lead Borate Tellurite and Zinc Borate Tellurite Glasses

    NASA Astrophysics Data System (ADS)

    Shigihalli, N. B.; Rajaramakrishna, R.; Anavekar, R. V.

    2011-07-01

    This paper describes the synthesis and optical absorption studies of the glass system 20PbO-20TeO2-(60-x)B2O3-x Eu2O3 (x = 0,1 mol %) and 20ZnO-20TeO2-(60-x)B2O3-xEu2O3 (x = 0,1 mol %). These glass systems have been successfully prepared by the melt quenching technique. The X-ray diffractograms show broad peaks indicating glasses are amorphous. DSC thermograms show glass transition temperatures around 655K for PbO content and around 675 K for ZnO content glass samples. In the UV-Visible spectra, several absorption lines are observed. The absorption peaks are around 362, 375, 393 and 464 nm for both Eu3+ doped PbO and ZnO content glass systems. These correspond to transitions from ground state of 7F0 to the excited state of 5D4, 5G4, 5L6 and 5D2 respectively for both Eu3+ doped PbO and ZnO content glass systems. These glasses are expected to give interesting applications in the area of optical devices.

  18. Spectroscopic investigations and physical properties of Mn 2+ doped mixed alkali zinc borate glasses

    Microsoft Academic Search

    T. Raghavendra Rao; Ch. Venkata Reddy; Ch. Rama Krishna; D. V. Sathish; P. Sambasiva Rao; R. V. S. S. N. Ravikumar

    2011-01-01

    Spectroscopic investigations on Mn2+ doped 20ZnO+xLi2O+(30?x)Na2O+50B2O3 (5?x?25) (ZLNB) glasses reveal the non-linear behavior in their physical and structural properties. FT-IR spectra of ZLNB glasses reveal diborate units in the borate network. EPR spectra exhibit characteristic resonance signals of Mn2+ ions. A well resolved six line hyperfine structure around g=2.02 corresponds to the sites of Type II, and a weak broad

  19. Structural, dielectric and AC conductivity properties of Co2+ doped mixed alkali zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Madhu, B. J.; Banu, Syed Asma; Harshitha, G. A.; Shilpa, T. M.; Shruthi, B.

    2013-02-01

    The Co2+ doped 19.9ZnO+5Li2CO3+25Na2CO3+50B2O3 (ZLNB) mixed alkali zinc borate glasses have been prepared by a conventional melt quenching method. The structural (XRD & FT-IR), dielectric and a.c. conductivity (?ac) properties have been investigated. Amorphous nature of these glasses has been confirmed from their XRD pattern. The dielectric properties and electrical conductivity (?ac) of these glasses have been studied from 100Hz to 5MHz at the room temperature. Based on the observed trends in the a.c. conductivities, the present glass samples are found to exhibit a non-Debye behavior.

  20. 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

  1. Absorption and emission properties of Ho 3+ doped lead–zinc–borate glasses

    Microsoft Academic Search

    N. Sooraj Hussain; N. Ali; A. G. Dias; M. A. Lopes; J. D. Santos; S. Buddhudu

    2006-01-01

    This paper reports on the affect of lead content on the absorption and emission spectra of the Ho3+ ion doped lead–zinc–borate glasses in the composition (mol%) of (20?x)PbO–20ZnO–(59+x)B2O3–1.0Ho2O3 where x=0, 5,10,15 of PbO content with ?exc=405 nm. The experimental absorption band energies have satisfactorily been correlated with the theoretical results with an r.m.s deviation of zero with the following correction

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

    SciTech Connect

    Lim, Jinhyong; Lee, Myeongkyu; Kim, Eunkyoung [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Department of Chemical Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2005-05-09

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

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

    SciTech Connect

    Gowda, G. V. Jagadeesha [Dept. of Physics, Sapthagiri College of Engineering, Bangalore-560057 (India); Eraiah, B. [Dept. of Physics, Bangalore University, Bangalore-560056 (India)

    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.

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

    PubMed

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

    2014-03-25

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    Glasses with compositions of (100-x) (Bi2ZnOB2O6) - x Nd2O3 (where x = 0.1, 0.3, 0.5, 1 and 2 mol%) were prepared by melt quenching method and characterized through optical absorption, emission and decay curve measurements. Optical absorption spectra have been analyzed using Judd-Ofelt theory. The emission spectra exhibit three peaks at 919, 1063 and 1337 nm corresponding to 4F3/2 to 4I9/2, 4I11/2 and 4I13/2 transitions in the near infrared region. The emission intensity of the 4F3/2 to 4I11/2 transition increases with increase of Nd3+ concentration up to 1 mol% and then concentration quenching is observed for 2 mol% of Nd3+ concentration. The lifetimes for the 4F3/2 level are found to decrease with increase in Nd2O3 concentration in the glasses. The decay curves of the glass up to 0.3 mol% of Nd3+ exhibit single exponential nature and thereafter the curves become nonexponential nature (0.5, 1 and 2 mol%). The nonexponential curve has been fitted to the Inokuti-Hirayama model to understand the nature of energy transfer process.

  6. 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.

  7. Optical studies of Sm³? ions doped zinc alumino bismuth borate glasses.

    PubMed

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

    2014-05-01

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

  8. Optical studies of Sm3+ ions doped Zinc Alumino Bismuth Borate glasses

    NASA Astrophysics Data System (ADS)

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

    Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of samarium (Sm3+) ions were prepared by using melt quenching technique and characterized for their lasing potentialities in visible region by using the techniques such as optical absorption, emission and emission decay measurements. Radiative properties for various fluorescent levels of Sm3+ ions were estimated from absorption spectral information using Judd-Ofelt (JO) analysis. The emission spectra and con-focal photoluminescence images obtained by 410 nm laser excitation demonstrates very distinct and intense orange-red emission for all the doped glasses. The suitable concentration of Sm3+ ions in these glasses to act as an efficient lasing material has been discussed by measuring the emission cross-section and branching ratios for the emission transitions. The quantum efficiencies were also been estimated from emission decay measurements recorded for the 4G5/2 level of Sm3+ ions. From the measured emission cross-sections, branching ratios, strong photoluminescence features and CIE chromaticity coordinates, it was found that 1 mol% of Sm3+ ions doped ZnAlBiB glasses are most suitable for the development of visible orange-red lasers.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  11. Light and heat driven precipitation of copper nanoparticles inside Cu 2+-doped borate glasses

    Microsoft Academic Search

    Yu Teng; Bin Qian; Nan Jiang; Yin Liu; Fangfang Luo; Song Ye; Jiajia Zhou; Bin Zhu; Heping Zeng; Jianrong Qiu

    2010-01-01

    We report on highly localized precipitation of copper nanoparticles in borate glasses by irradiation with femtosecond laser pulses. The area in the vicinity of the laser focal point of an 800nm femtosecond laser inside the glass sample became red due to the precipitation of copper nanoparticles after the femtosecond laser irradiation. The precipitation of copper nanoparticles was confirmed by transmission

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

    PubMed

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

    2014-12-10

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

  13. 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.

  14. Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

    NASA Astrophysics Data System (ADS)

    Tengku Kamarul Bahri, T. N. H.; Wagiran, H.; Hussin, R.; Saeed, M. A.; Hossain, I.; Ali, H.

    2014-10-01

    Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5-4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy.

  15. 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.

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

    SciTech Connect

    Abdel-Baki, Manal [Glass Department, National Research Centre, Dokki 12311 Giza (Egypt); Abdel-Wahab, Fathy A.; El-Diasty, Fouad [Physics Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo (Egypt)

    2012-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  18. Development of biomimetic coatings on Sm oxide doped ELB (Eu–Li–borate) glasses

    Microsoft Academic Search

    M. A. K. Elfayoumi; Wafa I. Abdel-Fattah; Gehan T. El-Bassyouni

    2010-01-01

    The in-vitro biomineralization of Eu\\/Li–borate glasses containing Sm2O3 was investigated by immersion in simulated body fluid (SBF) up to 72h. Back scattering scanning electron microscope supplemented with EDX was used to follow the development of the phosphatic layer post 72h SBF immersion. Biochemical analyses of calcium and inorganic phosphorus (Ca2+ and iP) ions were conducted using relevant biochemical kits and

  19. Optical characterization of Cu 2+ ion-doped zinc lead borate glasses

    Microsoft Academic Search

    A. Thulasiramudu; S. Buddhudu

    2006-01-01

    We have developed a new series of zinc lead borate (ZLB) glasses by varying ZnO content, to enhance UV transmission, in the chemical composition of xZnO–15PbO–(85?x)B2O3, where x=0, 5, 10, 15, 20, 25, 30, 35, 40 and 45mol% ZnO. From the measurement of UV absorption spectra both the direct and indirect band gaps have been evaluated. Also different physical properties

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  2. Photon Interaction Parameters for Some Borate Glasses

    SciTech Connect

    Mann, Nisha [Department of Applied Sciences, Samalkha Group of Institutions, Samalkha-132 101, Haryana (India); Kaur, Updesh; Singh, Tejbir; Sharma, J. K. [Department of Physics, Maharishi Markandeshwar University, Mullana-133 207, Haryana (India); Singh, Parjit S. [Department of Physics, Punjabi University, Patiala-147 002, Punjab (India)

    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.

  3. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  5. Optical absorption and photoluminescence properties of Dy3+ doped heavy metal borate glasses - Effect of modifier oxides

    NASA Astrophysics Data System (ADS)

    Sasi kumar, M. V.; Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

    2013-06-01

    The present paper aims at reporting the optical absorption and emission properties of Dy3+ doped alkali (Li, Na, K) and mixed alkali (Li-Na, Li-K, Na-K) heavy metal borate glasses. For these glasses X-ray diffraction (XRD), differential scanning calorimetry (DSC), optical absorption, emission and lifetime decay measurements were carried out. Glass transition temperatures are obtained from the DSC spectra. Judd-Ofelt theory has been used to derive the spectral intensities (f), Judd-Ofelt intensity parameters (?2, ?4 and ?6) and certain radiative properties. Using the Judd-Ofelt intensity parameters, radiative lifetimes (?R), branching ratios (?), integrated absorption cross-sections (?) and emission cross-sections (?P) were obtained. The variations in these parameters with the variation of glass matrix are discussed in detail. The decay lifetime of the 4F9/2 level has been measured from the decay profiles and compared with calculated lifetimes. From the emission spectra, chromacity color coordinates are calculated and indicated the white light emission for potassium glass matrices. It was observed that among various glass matrices, potassium glass matrix has exhibited large emission cross-section for 6F9/2 ? 6H13/2 transition.

  6. Optical absorption and photoluminescence properties of Er 3+ doped mixed alkali borate glasses

    Microsoft Academic Search

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

    2005-01-01

    An investigations of the optical absorption and fluorescence spectra of 0.2mol% Er2O3 in mixed alkali borate glasses of the type 67.8B2O3·xLi2O(32?x)Na2O, 67.8B2O3·xLi2O(32?x)K2O and 67.8B2O3·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°C, 1.5–2h) between two brass plates. Spectroscopic parameters like Racah

  7. Influence of PbO molar fraction and Se doping on borate glasses

    Microsoft Academic Search

    M. Rodríguez; I. Aguiar; L. Fornaro; A. C. Hernandes

    2008-01-01

    Glasses of xPbO(1-x)B2O3 composition, with x = 0.2, 0.4, 0.5 and 0.6, and doped with Se (0.01, 0.02, and 0.03 mol) were synthesized from H3BO3, PbO, Pb3O4 and Se powders, homogenized and then fused at about 700 - 800 ºC. The fused mixing was annealed at temperatures lower than the glass transition one, about 400 ºC and during 3 hours.

  8. Dosimetric properties of UV irradiated calcium co-doped borate glass–ceramic

    Microsoft Academic Search

    S. S. Rojas; K. Yukimitu; A. C. Hernandes

    2008-01-01

    The thermoluminescence (TL) response of Dy and Li doped 20CaB4O7–80CaB2O4 (wt%) glass–ceramic irradiated with ultraviolet (UV) radiation was studied. In order to act as TL activator ions, the Dy and Li ions were included in the matrix during the melting process to increase its TL efficiency. A single crystalline CaB2O4 phase was present in the glass–ceramic as determined by X-ray

  9. High-pressure fluorescence study of Sm3+-doped borate and fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Jayasankar, C. K.; Venkatramu, V.; Babu, P.; Tröster, Th.; Sievers, W.; Wortmann, G.; Holzapfel, W. B.

    2005-05-01

    Fluorescence spectra and decay properties of the G5/24 level of the Sm3+ ions have been measured in two glass systems of lithium borate and lithium fluoroborate glasses as a function of pressure up to 27.2 and 25.9 GPa, respectively, at room temperature. With an increase in pressure continuous redshifts of the G5/24?HJ6 (J =9/2,7/2, and 5/2) multiplet transitions as well as progressive increases in the magnitude of the splittings for these transitions are observed. Decay curves in both the systems exhibit perfect single exponential behavior at ambient pressure and become nonexponential at higher pressures accompanied by a moderate decrease in lifetimes. The nonexponential decay curves fit well to the Inokuti-Hirayama [M. Inokuti and F. Hirayama, J. Chem. Phys. 43, 1978 (1965)] model for S =6, indicating that the interaction for cross relaxation is of dipole-dipole type. The decrease in lifetime of the G5/24 level in both the systems with pressure is explained as resulting from the increase in the crystal-field strength felt by the Sm3+ ions due to volume reduction accompanied by a simultaneous increase in the electronic transition probabilities.

  10. Thermo-optical characteristics and concentration quenching effects in Nd3+ doped yttrium calcium borate glasses.

    PubMed

    Santos, D R S; Santos, C N; de Camargo, A S S; Silva, W F; Santos, W Q; Vermelho, M V D; Astrath, N G C; Malacarne, L C; Li, M S; Hernandes, A C; Ibanez, A; Jacinto, C

    2011-03-28

    In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd(2)O(3)-(5-x)Y(2)O(3-)40CaO-55B(2)O(3) (0 ? x ? 1.0 mol%). Their fluorescence quantum efficiency (?) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Förster-Dexter model of multipolar ion-ion interactions. A maximum ? = 0.54 was found to be substantially higher than for yttrium aluminoborate crystals and glasses with comparable Nd(3+) content. As for the thermo-optical properties of yttrium calcium borate, they are comparable to other well-known laser glasses. The obtained energy transfer microparameters and the weak dependence of ? on the Nd(3+) concentration with a high optimum Nd(3+) concentration put this system as a strong candidate for photonics applications. PMID:21456672

  11. Thermo-optical characteristics and concentration quenching effects in Nd3+doped yttrium calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Santos, D. R. S.; Santos, C. N.; de Camargo, A. S. S.; Silva, W. F.; Santos, W. Q.; Vermelho, M. V. D.; Astrath, N. G. C.; Malacarne, L. C.; Li, M. S.; Hernandes, A. C.; Ibanez, A.; Jacinto, C.

    2011-03-01

    In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd2O3-(5-x)Y2O3-40CaO-55B2O3 (0 ? x ? 1.0 mol%). Their fluorescence quantum efficiency (?) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Förster-Dexter model of multipolar ion-ion interactions. A maximum ? = 0.54 was found to be substantially higher than for yttrium aluminoborate crystals and glasses with comparable Nd3+ content. As for the thermo-optical properties of yttrium calcium borate, they are comparable to other well-known laser glasses. The obtained energy transfer microparameters and the weak dependence of ? on the Nd3+ concentration with a high optimum Nd3+ concentration put this system as a strong candidate for photonics applications.

  12. Judd-Ofelt analysis and spectral properties of Dy3+ ions doped niobium containing tellurium calcium zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Ravi, O.; Reddy, C. Madhukar; Reddy, B. Sudhakar; Deva Prasad Raju, B.

    2014-02-01

    Niobium containing tellurium calcium zinc borate (TCZNB) glasses doped with different concentrations of Dy3+ ions were prepared by the melt quenching method and their optical properties have been studied. The Judd-Ofelt (J-O) intensity parameters ?t (t=2, 4 and 6) were calculated using the least square fit method. Based on the magnitude of ?2 parameter the hypersensitivity of 6H15/2?6F11/2 has also been discussed. From the evaluated J-O intensity parameters as well as from the emission and lifetime measurements, radiative transition properties such as radiative transition probability rates and branching ratios were calculated for 4F9/2 excited level. It is found that for Dy3+ ion, the transition 4F9/2?6H13/2 shows highest emission cross-section at 1.0 mol% TCZNB glass matrix. From the visible luminescence spectra, yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were also estimated. The TCZNB glasses exhibit good luminescence properties and are suitable for generation of white light.

  13. Thermal and optical properties of Nd3+ doped lead zinc borate glasses—Influence of alkali metal ions

    NASA Astrophysics Data System (ADS)

    Sasi Kumar, M. V.; Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

    2013-04-01

    In the present investigation a new series of six different Nd3+ doped alkali and mixed alkali (Li, Na, K, Li-Na, Li-K and Na-K) heavy metal (PbO and ZnO) borate glasses were prepared using the melt quenching technique. The amorphous nature of the glass systems has been identified based on the X-ray diffraction analysis. The glass transition studies were carried out using differential scanning calorimetry (DSC). Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra. The Judd-Ofelt (J-O) theory has been applied to calculate J-O intensity parameters, ?? (?=2, 4 and 6) and in turn used to estimate radiative properties of certain transitions. Spectroscopic parameters such as transition probabilities (AT), branching ratios (?), radiative lifetimes (?R) and integrated absorption cross-sections (?) were calculated using J-O intensity parameters for all transitions. Using emission spectra, experimental branching ratios and stimulated emission cross-sections (?P) are obtained for all the observed emission transitions.

  14. Structural investigation and electron paramagnetic resonance of vanadyl doped alkali niobium borate glasses

    NASA Astrophysics Data System (ADS)

    Agarwal, A.; Sheoran, A.; Sanghi, S.; Bhatnagar, V.; Gupta, S. K.; Arora, M.

    2010-03-01

    Glasses with compositions xNb 2O 5·(30 - x)M 2O·69B 2O 3 (where M = Li, Na, K; x = 0, 4, 8 mol%) doped with 1 mol% V 2O 5 have been prepared using normal melt quench technique. The IR transmission spectra of the glasses have been studied over the range 400-4000 cm -1. The changes caused by the addition of Nb 2O 5 on the structure of these glasses have been reported. The electron paramagnetic resonance spectra of VO 2+ ions in these glasses have been recorded in X-band (9.14 GHz) at room temperature (300 K). The spin Hamiltonian parameters, dipolar hyperfine coupling parameter and Fermi contact interaction parameter have been calculated. It is observed that the resultant resonance spectra contain hyperfine structures (hfs) due to V 4+ ions which exist as VO 2+ ions in octahedral coordination with a tetragonal compression in the present glasses. The tetragonality of V 4+O 6 complex decreases with increasing concentration of Nb 2O 5. The 3d xy orbit contracts with increase in Nb 2O 5:M 2O ratio. Values of the theoretical optical basicity, ? th, have also been reported.

  15. Judd–Ofelt parameters and radiative properties of Sm 3+ ions doped zinc bismuth borate glasses

    Microsoft Academic Search

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

    2009-01-01

    Glasses having composition 20ZnO·xBi2O3·(79?x)B2O3 (15?x?35mol%) and doped with 1mol% Sm3+ ions have been prepared by melt quench technique. Optical absorption and fluorescence spectra have been recorded. Judd–Ofelt approach has been applied for the f?f transition of Sm3+ ions to evaluate various intensity parameters (?2,?4,?6). The variations in intensity parameters, radiative transition probabilities and hypersensitive band positions with composition have been

  16. Absorption and luminescence spectroscopy of zinc borate glasses doped with trivalent lanthanide ions

    NASA Astrophysics Data System (ADS)

    Ambrosi, Luigi; Bettinelli, Marco; Cormierand, Guy; Ferrari, Maurizio

    Absorption and luminescence spectra and decay curves have been measured at temperatures down to 12 K for 4ZnO-3B2O3 glasses doped with Pr3+ and Eu3+. Analysis of the spectra has yielded information about the probability of the radiative transitions in the impurity ions and the strength of the electron-phonon coupling. The strongly non-exponential decay curves indicate the importance of energy transfer and migration processes accounting for the dynamics of the excited states of Pr3+.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  18. Degradable borate glass polyalkenoate cements.

    PubMed

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

    2014-04-01

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

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

    PubMed

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

    2014-08-14

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

  20. Alkaline earth zinc borate glasses doped with Cu 2+ ions studied by EPR, optical and IR techniques

    Microsoft Academic Search

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

    2011-01-01

    Copper ions incorporated into alkaline earth zinc borate glasses 10RO+30ZnO+60B2O3 (R=Mg, Ca and Sr) and 10SrO+(30?x)ZnO+60B2O3+xCuO (x=0, 0.1, 0.3, 0.5, and 0.7wt.%) were characterized by electron paramagnetic resonance (EPR), optical absorption and FTIR techniques. The EPR spectra of all the glass samples exhibit resonance signals characteristic of Cu2+ ions. The values of spin-Hamiltonian parameters indicate that the Cu2+ ions in

  1. Optical characterization of Mn 2+, Ni 2+ and Co 2+ ions doped zinc lead borate glasses

    Microsoft Academic Search

    A. Thulasiramudu; S. Buddhudu

    2006-01-01

    This paper reports on the development and optical characterization of heavy metal oxide (HMO)-based transparent glasses in the chemical composition of 15PbO–40B2O3–(45?x) ZnO?x TM2+ (=Mn2+ or Ni2+ or Co2+) (where x=0.2, 0.5mol%). For these glasses both absorption and emission spectra have been measured, in order to understand their optical performances. The XRD profiles have confirmed their glassy nature and the

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    The structural and physical properties of xCuO(30-x)Bi2O3-70B2O3; x = 0, 5, 10, 15, 20 & 25 mol % with 2 mol % V2O5 glasses prepared by normal melt quench technique have been investigated by means of FT-IR & 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 BO3 to BO4 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 BiO3 pyramidal, BiO6 octahedral units and also on BO3 and BO4 structural units. The systematic variation in density and molar volume in these glasses indicates the effect of CuO substitution.

  3. XRD and EPR structural investigation of some zinc borate glasses doped with iron ions

    NASA Astrophysics Data System (ADS)

    Stefan, Razvan; Pascuta, Petru; Popa, Adriana; Raita, Oana; Indrea, Emil; Culea, Eugen

    2012-02-01

    Glasses in the system xFe2O3·(100-x) [45ZnO·55B2O3] (0?x?10 mol%) have been prepared by melting at 1200 °C and rapidly cooling at room temperature. The obtained samples were submitted to an additional thermal treatment at 570 °C for 12 h in order to relax the glass structure as well as to improve the local order. The as cast and heat treated samples were investigated using X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) measurements. The XRD patterns of all the studied samples show their vitreous nature. Structural modifications occurring in the heat treated samples compared to the untreated ones have been pointed out. EPR spectra of untreated and heat treated samples revealed resonance absorptions centered at g?2.0, g?4.3 and g?6.4. The compositional variation of the line intensity and linewidth of the absorptions from g?4.3 and g?2.0 have been interpreted in terms of the variation in the concentration of the Fe3+ ions and the interaction between the iron ions. The EPR spectra of the untreated samples containing 5 mol% Fe2O3 have been studied at different temperatures (110-290 K). The line intensity of the resonance signals decreases with increase in temperature whereas the linewidth is found to be independent of temperature. It was also found that the temperature variation of reciprocal line intensity obeys the Boltzmann law.

  4. Characterization of Cr3+ doped mixed alkali ions effect in zinc borate glasses - Physical and spectroscopic investigations

    NASA Astrophysics Data System (ADS)

    Rama Sundari, G.; Pushpa Manjari, V.; Raghavendra Rao, T.; Satish, D. V.; Rama Krishna, Ch.; Venkata Reddy, Ch.; Ravikumar, R. V. S. S. N.

    2014-06-01

    The physical and structural properties of Cr3+ doped 19.9 ZnO + xLi2O + (30 - x) Na2O + 50B2O3 (5 ? x ? 25) (ZLNB) glasses have been studied. Powder X-ray diffraction patterns indicated the amorphous nature of the glass samples. The physical parameters of all the glasses were also evaluated with respect to the composition. They exhibit the non-linearity providing the evidence for mixed alkali ions effect. The infrared spectra of the glasses in the range 400-4000 cm-1 showed the presence of BO3 and BO4 local structures in all the glass systems. No boroxol ring formation was observed in the structure of these glasses. Optical absorption and electron paramagnetic resonance studies were carried out at room temperature. From the optical absorption data various optical parameters such as optical band gap, Urbach energy were evaluated. Crystal field and Racah parameters are evaluated from optical absorption spectra. The EPR spectra of Cr3+ doped ZLNB glasses exhibited resonance signals at g = 4.066 and g = 1.9779 characteristic of Cr3+ ions. The evaluated bonding parameters suggest the covalent nature.

  5. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    Microsoft Academic Search

    M. M. I. Khalil

    2007-01-01

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration\\u000a was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that\\u000a the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration\\u000a dependent. Lithium borate

  6. Effect of Li 2O content on physical and structural properties of vanadyl doped alkali zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Raghavendra Rao, T.; Rama Krishna, Ch.; Udayachandran Thampy, U. S.; Venkata Reddy, Ch.; Reddy, Y. P.; Sambasiva Rao, P.; Ravikumar, R. V. S. S. N.

    2011-05-01

    The effect of Li 2O content in vanadyl doped 20ZnO+ xLi 2O+(30- x)Na 2O+50B 2O 3 (5? x?25) glasses has been studied with respect to their physical and structural properties. The absence of sharp peaks in XRD spectra of these glass samples confirms the amorphous nature. The physical parameters like density, refractive index, ionic concentration and electronic polarizability vary non-linearly with x mol% depending on the diffusivities of alkali ions. EPR and optical absorption spectra reveal that the resonance signals are characteristics of VO 2+ ions in tetragonally compressed octahedral site. Spin-Hamiltonian, crystal field, tetragonal field and bonding parameters are found to be in good agreement with the other reported glass systems. The tetragonal distortion ( g?- g?) and Dt reveals that their values vary non-linearly with Li 2O content and reaches a minimum at x=10 mol%. An anomaly of character has been observed in all the properties of vanadyl doped glass systems, which gives a clear indication of mixed alkali effect.

  7. Effect of MoO3 on electron paramagnetic resonance spectra, optical spectra and dc conductivity of vanadyl ion doped alkali molybdo-borate glasses

    NASA Astrophysics Data System (ADS)

    Agarwal, A.; Khasa, S.; Seth, V. P.; Sanghi, S.; Arora, M.

    2014-02-01

    Alkali molybdo-borate glasses having composition xMoO3·(30 - x)M2O·70B2O3 and xMoO3·(70 - x)B2O3·30M2O (M = Li, Na, K) with 0 ? x ? 15 (mol%) doped with 2.0 mol% of V2O5 have been prepared in order to study the influence of MoO3 on electrical conductivity, electron paramagnetic resonance (EPR) and optical spectra. From EPR studies it is observed that V4+ ions in these samples exist as VO2+ ions in octahedral coordination with a tetragonal compression and belong to C4V symmetry. The tetragonal nature and octahedral symmetry of V4+O6 complex increase as well as decrease depending upon the composition of glasses with increase in MoO3 but 3dxy orbit of unpaired electron in the VO2+ ion expands in all the glasses. The decrease in optical band gap suggests that there is an increase in the concentration of non-bridging oxygen's. From the study of optical transmission spectra it is observed that for all the glasses the degree of covalency of the ?-bonding decreases with increase in MoO3 content and the degree of covalency of the ?-bonding also varies. These results based on optical spectroscopy are in agreement with EPR findings. It is found that dc conductivity decreases and activation energy increases with increase in MoO3:M2O (M = Li, Na, K) ratio in MoO3·M2O·B2O3 glasses, whereas the conductivity increases and activation energy decreases with increase in MoO3:B2O3 ratio in xMoO3·B2O3·M2O glasses, which is governed by the increase in nonbridging oxygen's. The variation in theoretical optical basicity, ?th is also studied.

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

    Microsoft Academic Search

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

    2007-01-01

    The spectroscopic properties of Er3+\\/Yb3+ co-doped Bi2O3–B2O3–WO3 (BBW) glasses were analyzed and discussed. The effect of WO3 content on the absorption spectra, the Judd–Ofelt parameters ?t (t=2, 4, 6), emission spectra and the lifetime of the 4I13\\/2 level and the quantum efficiency of Er3+:4I13\\/2?4I15\\/2 transition were also investigated. With the substitution of WO3 for B2O3, the measured lifetime of the

  9. Bioactive borate glass coatings for titanium alloys

    Microsoft Academic Search

    Laxmikanth Peddi; Richard K. Brow; Roger F. Brown

    2008-01-01

    Bioactive borate glass coatings have been developed for titanium and titanium alloys. Glasses from the Na2O–CaO–B2O3 system, modified by additions of SiO2, Al2O3, and P2O5, were characterized and compositions with thermal expansion matches to titanium were identified. Infrared and X-ray diffraction\\u000a analyses indicate that a hydroxyapatite surface layer forms on the borate glasses after exposure to a simulated body fluid

  10. Structural properties of Zinc Lithium borate glass

    NASA Astrophysics Data System (ADS)

    Saidu, A.; Wagiran, H.; Saeed, M. A.; Alajerami, Y. S. M.

    2014-09-01

    Zinc Lithium Borate glasses of different composition were prepared with the aim of using it for thermoluminescence dosimetry. Melt quenching method was adopted in this process. Fourier transform Infrared (FTIR) spectroscopy and UV-vis-NIR spectroscopy techniques were employed to investigate the infrared spectra and energy band gap of different composition of Zinc Lithium Borate glasses. X-ray diffraction analysis was used to confirm the amorphous nature of the glass samples. Glass forming ability and stability of the glass was checked using Differential thermal analysis (DTA). Density, molar volume, refractive index parameters have been analyzed in the light of different concentration of the modifier. The active vibrational modes of 1200-1600 cm-1 for B-O stretching of BO3 units, 800-1200 cm-1 for B-O stretching of BO4 units and 400-800 cm-1 for bending vibration of various borate segments were detected. Addition of ZnO to lithium borate shows its influence in converting the dominant BO3 group to BO4 group. BO4 are known for creating complex defects, a situation that established deep and stable traps good for thermoluminescence phenomena. From optical data, direct and indirect energy band gap has been calculated using the data obtained from UV-vis-NIR spectroscopy. Both direct and indirect band gaps decrease with the increase of modifier Li2CO3.

  11. Borates

    USGS Publications Warehouse

    Angulo, M.A.

    2011-01-01

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

  12. Prediction of phase separation in binary borate glasses

    Microsoft Academic Search

    S. N. Crichton; M. Tomozawa

    1997-01-01

    Binary and ternary borate glasses were melted and examined to determine the immiscibility temperature for phase separation in each system. The critical temperatures of binary borate glasses are compared to the predicted critical temperatures from the Debye-Hückel model as developed for phase separated glasses and melts. When the anion structural unit is assumed to be a BO4? unit with a

  13. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    NASA Astrophysics Data System (ADS)

    Khalil, M. M. I.

    2007-03-01

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration dependent. Lithium borate glasses are subjected to carefully-programmed thermal treatments which cause the nucleation and growth of crystalline phases. X-ray diffraction analysis confirmed the amorphous nature for the investigated glass sample and the formation of crystalline phase for annealed samples at 650 °C. The main separated crystalline phase is Li2B8O13. The scanning electron micrographs of some selected glasses showed a significant change in the morphology of the films investigated due to heat treatment of the glass samples. It was found that the dc-conductivity decreases with an increase of the HT temperature. The decrease of dc conductivity, with an increase of the HT temperature, can be related to the decrease in the number of free ions in the glass matrix. There is deviation from linearity at high temperature regions in the log?-1/T plots for all investigated doped samples at a certain temperature at which the transition from polaronic to ionic conduction occurs. The hopping of small polarons is dominant at low temperatures, whereas the hopping of Li+ ions dominates at high temperatures.

  14. Effect of silver nanoparticles on the spectral properties of rare-earth ions in a sodium borate glass

    NASA Astrophysics Data System (ADS)

    Obadina, Victor O.; Reddy, B. Rami

    2012-03-01

    Silver doped sodium borate glass was made by the melt quenching technique. As made glass, did not reveal any absorption transitions in the visible or ultraviolet region. Differential scanning calorimeter was used to measure glass transition temperature. Heat treated glass revealed absorption peak at 410 nm due to surface plasmon resonance. Under violet laser excitation the glass revealed emission at 450 - 620 nm, whose lifetimes are more than 30?s. Under near resonant excitation it revealed intense Raman scattering. We also made multielement oxide glasses co-doped with silver and Er3+ and performed spectroscopic studies. Energy upconversion was observed from Er3+ at 415 nm in a 2% Ag co-doped oxide glass but not in other glasses. Infrared to visible upconversion studies were performed in all these glasses under near-infrared laser excitation. 2% Ag doped glass exhibited enhanced upconversion signals from erbium than that of other glasses.

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

    SciTech Connect

    Harihara Venkataraman, B. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan); Fujiwara, Takumi [Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Komatsu, Takayuki, E-mail: komatsu@mst.nagaokaut.ac.j [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan)

    2009-06-15

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

  16. Impact of vanadium ions in barium borate glass

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    Borate glasses of the 20R 2O·80B 2O 3 type, where R = Li, Na and K, were colored by doping with transition metal ions (Co, Ni, Cr and Mn). The glasses were obtained by melting at the temperature of 1150 °C. For these glasses optical absorption in UV-VIS-NIR range were recorded. Analysis of the spectra allows to be determined the coordination and oxidation states of the doping transition metal ions. Changes of their coordination or oxidation are presented as a function of the optical basicity ? after Duffy. Cobalt and nickel are present in examined borate glasses as divalent ions (Co 2+, Ni 2+) in octahedral coordination mainly, but the tetrahedral coordination state of cobalt is also possible. Chromium and manganese are present in the borate glasses in various oxidation state, though Cr 3+ and Mn 3+ ions in the octahedral coordination are probably dominant. A decrease of the electronegativity of the modifiers (Li ? Na ? K) and an increase of the glass matrix basicity cause a shift of the oxidation/reduction equilibrium towards higher valences of the transition metals (Cr 6+, Mn 3+).

  18. Infrared absorption spectroscopy of zinc borate and vanadium borate glasses

    Microsoft Academic Search

    C. A. Hogarth; M. M. Ahmed

    1983-01-01

    As part of a general research programme on oxide glasses we have studied the infrared absorption spectra in order to ascertain whether any local ordering characteristic of the constituent oxides is maintained in the final glass. Zachariasen [1] assumed as a general rule that in the amorphous state, the oxides which form such glasses are in energy states not much

  19. Relationship between Eu3+ reduction and glass polymeric structure in Al2O3-modified borate glasses under air atmosphere

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    The reduction of Eu3+ to Eu2+ is realized efficiently in Eu2O3-doped borate glasses prepared under air condition by melting-quenching method. Luminescent spectra show an increasing tendency of Eu2+ emission with increasing Al2O3 concentration in B2O3-Na2O glasses. It is interesting that significant enhancement appeared of Eu2+ luminescence in the Al2O3-rich sample comparing to the samples of Al2O3 less than 6 mol%. FTIR and Raman scattering measurements indicated that some new vibration modes assigned to the low-polymerized structure groups decomposed from the slight Al2O3 dopant samples. These results demonstrated that the polymerization of the glass structure decreased with increasing incorporation of Al2O3 into the borate glasses, linking to the efficiency of Eu3+ self-reduction in air at high temperature.

  20. 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.

  1. Electronic properties of calcium borate glasses containing iron oxide

    Microsoft Academic Search

    M. Gawish; M. N. Saleh

    1976-01-01

    The electronic properties of calcium borate glasses containing iron oxide have been investigated. It was found that glasses with an Fe2O3 content less than 20 mole% were amorphous, while those above 20 mole% were devitrified. It was observed that increasing the iron molar content in the amorphous samples caused an increase in their dc conductivity, ac conductivity, dielectric constant, and

  2. Optical gaps of alkali borate and alkali fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Suzuki, Takenobu; Hirano, Masahiro; Hosono, Hideo

    2002-04-01

    The optical gaps of B2O3 alkali borate, and alkali fluoroborate glasses were determined by using blown films. The gap of B2O3 glass was 8.0 eV and the value decreased monotonically with decreasing the B2O3 content in both fluoroborate and borate glasses. When compared at a constant B2O3 content, the gap is in the order Li>Na>K and fluoroborate>borate. Ab initio molecular orbital calculation on the model clusters of the glasses revealed that the lowest excitations in B2O3 and alkali (fluoro) borate glasses are the transitions from nonbonding 2p orbitals of oxygen atoms in boroxol rings to vacant nonbonding 2p orbitals of boron atoms on "loose" BO3 triangles and from nonbonding 2p orbitals of oxygen atoms bonded with borons in tetrahedral coordination to the vacant ns orbitals of neighboring alkali ions, respectively. The vacant ns orbitals of the alkali ions neighboring oxygen atoms attached to tetrahedral borons primarily contribute to the lowest unoccupied molecular orbital (LUMO) levels. On the other hand, fluorine indirectly contributes to lowering the highest occupied molecular orbital (HOMO) levels via inductive effect (polarization of B-F ?-bond). It was therefore concluded that the effect of alkali addition on lowering LUMO levels is larger than that of fluorine addition on lowering the HOMO level.

  3. Structure of fast-ion-conducting lithium and sodium borate glasses by neutron diffraction and reverse Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Swenson, J.; Börjesson, L.; Howells, W. S.

    1998-06-01

    The structures of fast-ion-conducting glasses (NaZ)x(Na2O-2B2O3)1-x and (LiZ)x(Li2O-2B2O3)1-x (Z=Cl,Br) have been examined by neutron diffraction and reverse Monte Carlo (RMC) simulations. The short-range structure of the boron-oxygen network is almost unchanged for increasing dopant salt concentration and independent of the dopant salt, whereas the intermediate range order of the B-O network decreases significantly for increasing dopant salt concentration. The sodium borate glasses are generally slightly more ordered than the corresponding lithium borate glasses. The differences may be explained by the fact that the Li-borate glasses consist of a disordered random mixture of many different types of borate configurations, while the Na-borate glasses are built up by randomly distributed diborate groups, as suggested previously from NMR results. The RMC simulations of the highest LiCl- and NaCl-doped glasses show, however, that large density fluctuations are present within the boron-oxygen network. The voids are of widely different sizes and geometrical shapes. The present findings show that the intermediate-range order of the LiCl- and NaCl-doped glasses is significantly different from that recently reported for the corresponding AgI-doped glass. For the latter the boron-oxygen network forms a more ordered chainlike structure with the salt ions cross linking between the ``chains.''

  4. Conduction models of semiconducting calcium borate glasses containing iron oxide

    Microsoft Academic Search

    M. N. Saleh; M. M. Gawish

    1980-01-01

    The ac electrical resistivity, dielectric constant, and dielectric loss of the calcium borate glass system are investigated in order to determine the conduction models of the system. The glass series contains different iron concentrations in the system of molar composition (70-x)B2O3-30CaO-xFe2O3 with x up to 32%. The electronic properties are measured from 77 to 800 °K in the frequency range

  5. Structural and acoustic investigations of calcium borate glasses

    Microsoft Academic Search

    Manupriya; K. S. Thind; G. Sharma; V. Rajendran; K. Singh; A. V. Gayathri Devi; S. Aravindan

    2006-01-01

    Acoustic and structural properties of x CaO . (1-x ) B2O3 (0.2 x 0.7) glass system have been studied at ambient temperature. The ultrasonic velocity and attenuation for different compositions of calcium borate glasses were measured at 5 MHz at room temperature (303 K) using a pulse echo overlap method. The elastic moduli, Debye temperature, Poisson's ratio and other acoustic

  6. Spectroscopic properties of Dy 3+ ions in lithium borate and lithium fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Babu, P.; Jayasankar, C. K.

    2000-09-01

    Spectral study of Dy 3+-doped borate glasses modified with lithium oxide and fluoride are presented. These glasses include lithium borates: (99- x)Li 2CO 3+ xH 3BO 3+1Dy 2O 3, x=39.5, 49.5, 59.5 and 69.5 and lithium fluoroborates: xLi 2CO 3+(49.5- x)LiF+49.5H 3BO 3+1Dy 2O 3, x=24.75 and 0. Using Judd-Ofelt (JO) theory, the intensity parameters ( ? ?, ?=2,4,6 ) have been evaluated for all the six glasses. These intensity parameters are used to predict radiative properties that include electric ( Sed) and magnetic ( Smd) dipole line strengths, radiative ( A) and total radiative ( AT) transition probabilities, lifetimes ( ?R), branching ratios ( ?R) for the excited ( 4K(1) 13/2, 4F(3) 5/2, 4P(2) 3/2, 4M21/2, 4G(4) 11/2, 4I(3) 15/2, 4F(3) 9/2, 6F9/2 and 6H9/2) levels of these Dy 3+-doped lithium borate and lithium fluoroborate glasses along with 11 different systems doped with Dy 3+ ions. The predicted values of ?R and ?R are compared with the experimental values for 4F(3) 9/2 transition. The stimulated emission cross-sections are also evaluated for 4F(3) 9/2 ? 6HJ ( J=7/2,9/2,11/2,13/2 and 15/2) transitions. The dependence of the spectral characteristics of Dy 3+ ions due to compositional changes of the glasses are examined.

  7. Fluorescent borate glass superstrates for high efficiency CdTe solar cells

    NASA Astrophysics Data System (ADS)

    Steudel, Franziska; Dyrba, Marcel; Schweizer, Stefan

    2012-06-01

    Sm3+-doped barium borate glasses are investigated for their potential as a superstrate for CdTe solar cells. The influence of the Sm3+ conversion efficiency and the Sm2O3 doping level on the short circuit current density of a CdTe solar cell is analyzed. CdTe solar cells with CdS layer thicknesses of 45 and 300 nm are evaluated. A 3.2 mm thick, 2 mol% Sm2O3- doped glass superstrate enables a relative increase in the short circuit current density of approximately 1.4% and 2.9% for a 45 and 300 nm CdS buffer layer, respectively, assuming 100% Sm3+ conversion efficiency.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi2O+yNa2O+80B2O3 (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 (Li2O and Na2O) 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 (BO4/2)- into (BO3/2)-. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  10. Cell adhesion to borate glasses by colloidal probe microscopy.

    PubMed

    Wiederhorn, Sheldon M; Chae, Young-Hun; Simon, Carl G; Cahn, Jackson; Deng, Yan; Day, Delbert

    2011-05-01

    The adhesion of osteoblast-like cells to silicate and borate glasses was measured in cell growth medium using colloidal probe microscopy. The probes consisted of silicate and borate glass spheres, 25-50 ?m in diameter, attached to atomic force microscope cantilevers. Variables of the study included glass composition and time of contact of the cell to the glasses. Increasing the time of contact from 15 to 900 s increased the force of adhesion. The data could be plotted linearly on a log-log plot of adhesive force versus time. Of the seven glasses tested, five had slopes close to 0.5, suggesting a square root dependence of the adhesive force on the contact time. Such behavior can be interpreted as a diffusion limited process occurring during the early stages of cell attachment. We suggest that the rate limiting step in the adhesion process is the diffusion of integrins resident in the cell membrane to the area of cell attachment. Data presented in this paper support the hypothesis of Hench et al. that strong adhesion depends on the formation of a calcium phosphate reaction layer on the surfaces of the glass. Glasses that did not form a calcium phosphate layer exhibited a weaker adhesive force relative to those glasses that did form a calcium phosphate layer. PMID:21241832

  11. Reaction of sodium calcium borate glasses to form hydroxyapatite

    Microsoft Academic Search

    Xue Han; Delbert E. Day

    2007-01-01

    This study investigated the transformation of two sodium calcium borate glasses to hydroxyapatite (HA). The chemical reaction\\u000a was between either 1CaO · 2Na2O · 6B2O3 or 2CaO · 2Na2O · 6B2O3 glass and a 0.25 M phosphate (K2HPO4) solution at 37, 75 and 200 °C. Glass samples in the form of irregular particles (125–180 ?m) and microspheres (45–90 and\\u000a 125–180 ?m) were used in order to understand the reaction mechanism. The effect

  12. 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.

  13. Temperature dependence of elastic properties in alkali borate binary glasses

    NASA Astrophysics Data System (ADS)

    Kawashima, Mitsuru; Matsuda, Yu; Kojima, Seiji

    2011-05-01

    The elastic properties of alkali borate glasses, xM 2O·(100 - x)B 2O 3 (M = Li, Na, K, Rb, Cs, x = 14, 28), have been investigated by Brillouin scattering spectroscopy from room temperature up to 1100 °C. Above the glass transition temperature, Tg, the longitudinal sound velocity, VL, decreases markedly on heating. Such significant changes of the elastic properties result from the breakdown of the glass network above Tg. Alkali borate family with the same x shows the similar behavior in the temperature variations of VL up to around Tg. The absorption coefficient, ?L, increases gradually above Tg. With the increase of the size of an alkali ion, the slope of VL just above Tg decreases. Since the fragility is related to the slope, the present results suggest that the fragility of alkali borate glasses increases as the size of alkali ion decreases. Such an alkali dependence of the fragility is discussed on the basis of the fluctuation of the boron coordination number.

  14. Conduction models of semiconducting calcium borate glasses containing iron oxide

    NASA Astrophysics Data System (ADS)

    Saleh, M. N.; Gawish, M. M.

    1980-01-01

    The ac electrical resistivity, dielectric constant, and dielectric loss of the calcium borate glass system are investigated in order to determine the conduction models of the system. The glass series contains different iron concentrations in the system of molar composition (70-x)B2O3-30CaO-xFe2O3 with x up to 32%. The electronic properties are measured from 77 to 800 °K in the frequency range from 20 Hz to 100 kHz. The work has proved that the glasses are electronically conducting. The experimental results support the following models of conduction: (a) hopping conduction for glasses containing less than 20 mole% Fe2O3, (b) trap-limited band conduction together with hopping conduction for glasses having Fe2O3 mole% between 20 and 30, and (c) diffusive conduction together with hopping conduction for glasses containing more than 30 mole% Fe2O3.

  15. Optical properties of Dy3+ doped yttrium aluminium borate

    Microsoft Academic Search

    R. Martínez Vázquez; R. Osellame; M. Marangoni; R. Ramponi; E. Diéguez; M. Ferrari; M. Mattarelli

    2004-01-01

    A Dy3+ doped yttrium-aluminium borate (Dy:YAB) crystal has been optically characterized. The refractive indices at seven different wavelengths, ranging from the visible to the near infrared (IR), have been measured and the Sellmeier curves have been calculated. The polarized optical absorption spectra have been obtained at room temperature, and the Judd-Ofelt parameters have been calculated. The lifetime of the upper

  16. Wavelength interdependence assessment of all-optical switching in zinc borate glasses

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

    Lithium tungsten borate photonic glass is prepared by the conventional melt-quench technique. Due to semiconductor-like behavior of zinc oxide, the glass is doped by ZnO to adapt its optical nonlinearity. Fresnel-based spectrophotometric measurements and Lorentz dispersion theory are applied to study (in a very wide range of photon energy from 0.5 to 6.2 eV) the dispersion of second-order refractive index, two-photon absorption coefficient, and third-order optical susceptibility of the glass. The figure of merit (FOM) needed for optical switching applications is estimated. We reveal the importance of determining the dispersion of the optical nonlinear parameters to find out the appropriate operating wavelength for optimum FOM of the glass.

  17. CORROSION PROPERTIES OF CALCIUM-BISMUTH-BORATE GLASSES WITH SILVER

    Microsoft Academic Search

    V. SIMON; M. SPINU; R. TEFAN

    Quaternary Ag 2O-CaO-Bi 2O3-B2O3 glasses are investigated with regard to release behaviour and local structure. The dissolution beha viour in water and physiological serum shows that the cations are released rapidly or gradually and p oints out a multi-step process, generally characterised by higher rates in water than in phys iological serum. The structural effect of silver addition to bismuth-borate

  18. Electronic spectroscopy of trivalent lanthanide ions in lead zinc borate glasses

    Microsoft Academic Search

    Adolfo Speghini; Massimo Peruffo; Maurizio Casarin; David Ajò; Marco Bettinelli

    2000-01-01

    New zinc borate glasses of composition 4PbO·2ZnO·5B2O3· and 2PbO·4ZnO·5B2O3 doped with Pr3+, Nd3+, Eu3+, Dy3+, Ho3+ and Er3+ were prepared. Absorption and luminescence spectra were measured and the Judd–Ofelt parameters were calculated. The spectroscopic behaviour appears to be strongly influenced by the presence of the highly polarizable Pb2+ ion. The values of stimulated emission cross sections for selected laser transition

  19. Thermal Expansion and Glass Transition Temperature of Calcium Borate and Calcium Aluminoborate Glasses

    Microsoft Academic Search

    V. P. Klyuev; B. Z. Pevzner

    2003-01-01

    The thermal expansion (the temperature coefficients of linear expansion for solid glasses and the structural temperature coefficients of linear expansion) and the glass transition temperatures are studied for glasses in the CaO–B2O3 and CaO–B2O3–Al2O3 systems. The results obtained are compared with the available data for barium borate and barium aluminoborate glasses. The revealed dependences are interpreted within the concepts of

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

    PubMed

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

    2013-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi2O3-30ZnO-(70-x) B2O3 (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 (?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. Third order nonlinear optical properties of bismuth zinc borate glasses

    SciTech Connect

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in [Department of Physics, Pondicherry University, Puducherry 605 014 (India); Kuladeep, R.; Narayana Rao, D. [School of Physics, University of Hyderabad, Hyderabad 500046, Andhra Pradesh (India)

    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.

  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. [Department of Physics,Sri Venkateswara University,Tirupati-517502 (India)

    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. Conductivity and dielectric relaxation in niobium alkali borate glasses

    NASA Astrophysics Data System (ADS)

    Sanghi, Sujata; Sheoran, Anshu; Agarwal, Ashish; Khasa, Satish

    2010-12-01

    The frequency and temperature dependent conductivity investigations for alkali niobium borate glasses of composition xNb 2O 5·(30- x)M 2O·70B 2O 3 (where M=Li, Na; x=0, 4, 8 mol%) have been carried out using impedance spectroscopy (IS). The complex impedance data have been analyzed by using both the conductivity and the electric modulus formalisms. The conductivity decreases with the decrease in M 2O:Nb 2O 5 ratio. The effect of temperature on the scaling of dielectric modulus indicates that the conductivity relaxation mechanism is temperature independent. The overlapping of the normalized peaks corresponding to impedance and electric modulus and the identical values of thermal activation energy for conduction and relaxation suggest the single mechanism for the dynamic processes occurring in the present glasses. The variation of density, molar volume and glass transition temperature with glass composition has also been reported to supplement the conductivity results.

  5. Reaction of sodium calcium borate glasses to form hydroxyapatite.

    PubMed

    Han, Xue; Day, Delbert E

    2007-09-01

    This study investigated the transformation of two sodium calcium borate glasses to hydroxyapatite (HA). The chemical reaction was between either 1CaO . 2Na(2)O . 6B(2)O(3) or 2CaO . 2Na(2)O . 6B(2)O(3) glass and a 0.25 M phosphate (K(2)HPO(4)) solution at 37, 75 and 200 degrees C. Glass samples in the form of irregular particles (125-180 microm) and microspheres (45-90 and 125-180 microm) were used in order to understand the reaction mechanism. The effect of glass composition (calcium content) on the weight loss rate and reaction temperature on crystal size, crystallinity and grain shape of the reaction products were studied. Carbonated HA was made by dissolving an appropriate amount of carbonate (K(2)CO(3)) in the 0.25 M phosphate solution. X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used to characterize the reaction products. The results show that sodium calcium borate glasses can be transformed to HA by reacting with a phosphate solution. It is essentially a process of dissolution of glass and precipitation of HA. The transformation begins from an amorphous state to calcium-deficient HA without changing the size and shape of the original glass sample. Glass with a lower calcium content (1CaO . 2Na(2)O . 6B(2)O(3)), or reacted at an elevated temperature (75 degrees C), has a higher reaction rate. The HA crystal size increases and grain shape changes from spheroidal to cylindrical as temperature increases from 37 to 200 degrees C. Increase in carbonate concentration can also decrease the crystal size and yield a more needle-like grain shape. PMID:17486301

  6. 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

  7. Structural and acoustic investigations of calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Manupriya; Thind, K. S.; Sharma, G.; Rajendran, V.; Singh, K.; Gayathri Devi, A. V.; Aravindan, S.

    2006-08-01

    Acoustic and structural properties of x CaO . (1-x ) B2O3 (0.2 x 0.7) glass system have been studied at ambient temperature. The ultrasonic velocity and attenuation for different compositions of calcium borate glasses were measured at 5 MHz at room temperature (303 K) using a pulse echo overlap method. The elastic moduli, Debye temperature, Poisson's ratio and other acoustic parameters have been obtained from experimental data. Fourier transform infrared spectroscopic analysis has been used to further support the results of acoustic studies. The results obtained indicate that the calcium oxide enters the glass network as a modifier by occupying the interstitial spaces in the network and by increasing the nonbridging oxygen atoms (NBOs).

  8. Thermal, structural and electrical studies of bismuth zinc borate glasses

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    Bismuth Zinc Borate glasses with compositions xBi2O3-30ZnO-(70 - x)B2O3 (where x = 30, 35, 40 and 45 mol %) have been prepared by melt quenching method. These glasses were characterized by X-ray diffraction (XRD), Differential Thermal Analysis (DTA), Fourier Transform Infrared Spectrometer (FTIR) and Broad Band Dielectric Spectrometer (BDS). DTA and FTIR analysis reveals that Non-Bridging Oxygens (NBOs) increase with increase of bismuth content in the glass. Electrical data have been analyzed in the framework of impedance and modulus formalisms. The activation energy for dc conductivity decreases with increase of bismuth concentration. The imaginary part of modulus spectra has been fitted to non-exponential Kohlrausch-Williams-Watts (KWW) function and the value of the stretched exponent (?) is found to be almost independent of temperature but slightly dependent on composition.

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

    SciTech Connect

    Subhashini,, E-mail: subhashini.p.p@gmail.com; Bhattacharya, Soumalya, E-mail: subhashini.p.p@gmail.com; Shashikala, H. D., E-mail: subhashini.p.p@gmail.com; Udayashankar, N. K., E-mail: subhashini.p.p@gmail.com [Department of Physics, National Institute of Technology Karnataka, Surathkal-575025 (India)

    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.

  10. Preparation and characterization of magnesium borate for special glass

    NASA Astrophysics Data System (ADS)

    Dou, Lishuang; Zhong, Jianchu; Wang, Hongzhi

    2010-05-01

    Magnesium borate with a variety of B2O3/MgO molar ratios, which can be applied for special glass, has been prepared through the reaction of light-burned magnesia with boric acid by a hydrothermal method. The effects of the B2O3/MgO molar ratio of raw materials, reaction time, temperature and liquid to solid ratio (ml g-1) on the synthetic product are investigated. The XRD and TG-DTG analyses indicate that the prepared magnesium borate is a mixture of magnesium hexaborate hydrate and ascharite. The results show that high B2O3/MgO molar ratios of raw materials and low reaction liquid-solid ratios favour the product with a high B2O3/MgO molar ratio and vice versa. There exists free MgO in the product when the reaction temperature is below 140 °C or the reaction time is not enough, because of the incomplete reaction of magnesium oxide with boric acid. The process of fractional crystallization for the magnesium borate mixture is also discussed.

  11. Optical properties of lead borate glasses containing Dy3+ ions

    Microsoft Academic Search

    Joanna Pisarska

    2009-01-01

    Optical properties of lead borate glasses containing Dy3+ ions were examined using absorption and luminescence measurements and theoretical calculations based on the Judd-Ofelt framework and the Inokuti-Hirayama model. The luminescence spectra show two characteristic bands at 480 and 573 nm, which are due to 4F9\\/2-6H15\\/2 (blue) and 4F9\\/2-6H13\\/2 (yellow) transitions of trivalent Dy3+ ions. The yellow\\/blue luminescence and its decay

  12. 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.

  13. Ytterbium-doped borate fluoride laser crystals and lasers

    DOEpatents

    Schaffers, Kathleen I. (Pleasanton, CA); DeLoach, Laura D. (Manteca, CA); Payne, Stephen A. (Castro Valley, CA); Keszler, Douglas A. (Corvallis, OK)

    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.

  14. Borates

    USGS Publications Warehouse

    Crangle, R.D., Jr.

    2013-01-01

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

  15. Persistent spectral hole burning of Sm 2+ in borate glasses

    Microsoft Academic Search

    D. H. Cho; K. Hirao; N. Soga

    1995-01-01

    It is expected that persistent spectral hole burning (PSHB) will be applied for a high-density data storage system and it can serve as a powerful method for studying the local structure around optical centers. The authors' group has discovered a room-temperature PSHB material for Sm2+-doped glasses. The present work investigated the relationship between the Debye temperature of the glass and

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  17. Spectroscopy of Pr 3+ ions in lithium borate and lithium fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Babu, P.; Jayasankar, C. K.

    2001-08-01

    Optical absorption and emission spectra of 1 mol% Pr 3+ doped lithium borate and lithium fluoroborate glasses have been recorded. The intensities of f-f transitions are parameterized in terms of Judd-Ofelt (JO) intensity parameters ?? ( ?=2, 4 and 6). The JO parameters obtained with modified JO theory have been used to predict radiative properties such as spontaneous emission probabilities ( A), lifetimes ( ?R) and branching ratios ( ?R) for all the 12 excited states of these Pr 3+ doped glasses along with some of the reported Pr 3+ : systems. The predicted ?R are compared with the experimental values for the emission from 3P 0 and 3P 1 levels. The stimulated emission cross-sections are also evaluated for all the observed emission transitions. The ?R values for the potential laser transitions including the 1G 4? 3H 5 (1.3 ?m) transition useful for fibre amplifier have been compared for 17 Pr 3+ : systems. The effect of compositional changes of the glasses on the optical properties of Pr 3+ ions have been discussed.

  18. On the Elastic behavior of Sodium Borate Glasses

    NASA Astrophysics Data System (ADS)

    Vignarooban, K.; Boolchand, P.; Kerner, R.; Micoulaut, M.

    2010-03-01

    Alkali Borates are industrial glasses and their physical properties are of general interest. We have made a special effort to synthesize dry (Na2O)x(B2O3)100-x glasses over a wide composition range, 0 < x < 70%, and have examined them in modulated-DSC, Raman scattering, FTIR, and molar volume experiments. The enthalpy of relaxation at Tg shows a global minimum in the 20% < x < 40% range, which we identify with the rigid but stress-free Intermediate Phase (IP). The Boroxyl ring vibrational mode near 808 cm-1 in B2O3, steadily softens by about 4 cm-1 as the soda content increases to about 20%. A vibrational mode of mixed ringsfootnotetextKamitsos et al., Jour. Mol. Struct 247, 1 (1996). (containing 3-fold and 4-fold B) is also observed near 775 cm-1 at low x, and it also steadily softens by nearly 10 cm-1 as x increases in the 20% < x < 40% soda range (IP). We are examining the underlying optical elasticity power-laws to ascertain the nature of the elastic phases. IR reflectance experiments provide the 4-fold coordinated B fraction to increase from 0.17 near x = 20% to 0.44 near x = 40% in broad agreement with NMR results. Evolution of physical properties of these glasses with soda content will be reviewed.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  20. Optical and ESR investigation of borate glasses containing single and mixed transition metal oxides

    Microsoft Academic Search

    A. K. Bandyopadhyay

    1981-01-01

    The optical and electron spin resonance (ESR) spectra of barium borate glasses, containing the oxides of V, Fe and Cu separately and in mixed proportions, have been studied. The optical spectra of the single transition metal (TM) oxide glasses showed the usual features, while those for the mixed glasses showed single bands without showing individual features of the single TM

  1. Atom probe tomography of lithium-doped network glasses.

    PubMed

    Greiwe, Gerd-Hendrik; Balogh, Zoltan; Schmitz, Guido

    2014-06-01

    Li-doped silicate and borate glasses are electronically insulating, but provide considerable ionic conductivity. Under measurement conditions of laser-assisted atom probe tomography, mobile Li ions are redistributed in response to high electric fields. In consequence, the direct interpretation of measured composition profiles is prevented. It is demonstrated that composition profiles are nevertheless well understood by a complex model taking into account the electronic structure of dielectric materials, ionic mobility and field screening. Quantitative data on band bending and field penetration during measurement are derived which are important in understanding laser-assisted atom probe tomography of dielectric materials. PMID:24713345

  2. Optical and structural characterization of yttrium calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Santos, Cristiane; Meneses, Domingos D. S.; Echegut, Patrick; Neuville, Daniel R.; Hernandes, Antonio C.; Ibanez, Alain

    2010-03-01

    Structural and optical properties of new stable glasses in the Y2O3 -- CaO -- B2O3 system, containing the same Y/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy [1]. We have obtained the optical functions using a dielectric function model and their evolution with composition are associated with an increase in the number of non-bridging oxygen and to calcium/yttrium oxides content with the formation of pentaborate, metaborate, orthoborate and pyroborate groups. The orthoborate and pyroborate signatures increase with increasing the modifier cations. Refractive indexes values (from 1.597 to 1.627 at ? = 2 ?m) are in good agreement with those of the YCOB crystal, an indication that these glasses are potential candidates for doping with rare-earth ions for optical applications. [4pt] [1] C. N. Santos, D.D.S. Meneses, P. Echegut, D. R. Neuville, A. C. Hernandes, A. Ibanez, Appl. Phys. Lett. 94, 151901(2009).

  3. Determination of thermoluminescence kinetic parameters of thulium doped lithium calcium borate

    Microsoft Academic Search

    M. T. Jose; S. R. Anishia; O. Annalakshmi; V. Ramasamy

    2011-01-01

    For the first time kinetic parameters of thulium doped Lithium calcium borate (LCB) Thermoluminescence (TL) material are reported here. Irradiated LCB:Tm3+ powder has revealed two intense TL glow peaks one at 510 (peak 1) and the other at 660K (peak 2). Activation energy (E), frequency factor (s) and order of kinetics (b) of these peaks were determined by various heating

  4. ROLE OF CERIUM IN SUPPRESSION OF GAMMA-RAY INDUCED COLORING OF BORATE GLASSES

    Microsoft Academic Search

    ADLI M. BISHAY

    1962-01-01

    The role of cerium in the suppression of gamma-ray induced coloration in ; glass was found to depend on the relative concentration of Ce\\/sup 3+\\/ to Ce\\/sup ; 4+\\/ ions as well as on the total cerium content. In a borate glass having high ; ultraviolet transmission, it was found that both Ce\\/sup 3+\\/ and Ce\\/sup 4+\\/ ions ; are

  5. 2pm\\/V in Poled Bismuth-Zinc-Borate High Index Glass

    Microsoft Academic Search

    C. Corbari; L. Chandru; I. C. S. Carvalho; O. Deparis; F. P. Mezzapesa; P. G. Kazansky; K. Sakaguchi

    2009-01-01

    This paper demonstrates 2 pm\\/V in poled bismuth-zinc-borate glass planar waveguides. The innovative sample configuration, which provides a 4-fold improvement in the induced chi(2) compared to bulk glasses, is suggested by a poling model that takes into account both ionic and electronic conduction. The second-order nonlinearity chi(2) is found to be limited by the onset of nonlinear conductivity. Thus, this

  6. X-ray photoemission study of Pr in zinc borate glasses

    Microsoft Academic Search

    G. Speranza; M. Ferrari; M. Bettinelli

    1999-01-01

    This work reports the X-ray photoelectron spectroscopy of a zinc borate glass activated by different concentrations (0, 1, 2, 4, and 8mol%) of Pr. The modification induced on the glass structure by the Pr ions was investigated, and a quantitative measure of the non-bridging-to-bridging-oxygen ratio around the Pr ion was obtained. The analysis of the O ls core line showed

  7. Reaction of SiC{sub f}\\/SiC composites with a zinc borate glass

    Microsoft Academic Search

    P. Lemoine; M. Salvo; M. Ferrais; M. Montorsi; H. Scholz

    1995-01-01

    Two different types of SiC{sub f}\\/SiC composites were successfully joined using a zinc borate glass as a joining agent. The characterization of the joined specimens included XRD, DSC, DTA, SEM-EDS, macroporosimetry, and shear testing measurements. For both composites, the interfaces were continuous and crack-free, and a reaction occurred between the liquid glass and the composite`s surface. The large porosity of

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    Goetschius, Kathryn Lynn

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

  10. Effect of alkali content on AC conductivity of borate glasses containing two transition metals

    NASA Astrophysics Data System (ADS)

    Kashif, I.; Rahman, Samy A.; Soliman, A. A.; Ibrahim, E. M.; Abdel-Khalek, E. K.; Mostafa, A. G.; Sanad, A. M.

    2009-11-01

    Sodium borate glasses containing iron and molybdenum ions with the total concentration of transition ions constant and gradual substitution of sodium oxide (network modifier) by borate oxide (network former) was prepared. Densities, molar volume, DC and AC conductivities are measured. The trends of these properties are attributed to changes in the glass network structure. Their DC and AC conductivity increased with increasing NaO concentration. The increase of AC conductivity of sodium borate glasses is attributed to the chemical composition and the hopping mechanism of conduction. Measurements of the dielectric constant ( ?) and dielectric loss (tan ?) as a function of frequency (50 Hz-100 kHz) and temperature (RT-600 K) indicate that the increase in dielectric constant and loss ( ? and tan ?) values with increasing sodium ion content could be attributed to the assumption that Fe and Mo ions tend to assume network-forming position in the glass compositions studied. The variation of the value of frequency exponent s for all glass samples as the function of temperature at a definite frequency indicates that the value of s decreases with increasing the temperature which agrees with the correlated barrier-hopping (CBH) model.

  11. Erbium doped glasses for optical fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Wójcik, Joanna; Dorosz, Dominik

    2008-01-01

    The optical and physical properties of three different glass systems were presented. The obtained glasses were doped with 1,75wt% erbium oxide (Er IIO 3). Transmission and luminescence spectra were measured. Absorption spectra were calculated on the basis of transmission spectra. Classic active optical fiber doped with 1,75wt% erbium oxide was fabricated. Attenuation of fabricated optical fiber was measured.

  12. Mechanical property evaluation of porous 13-93 Bioactive Glass and GL1550 Borate Glass 3D scaffolds D. Li, A. Scully, and T. M. G. Chu

    E-print Network

    Zhou, Yaoqi

    -glass (A) and GL1550 borate bioactive-glass (B) powders, at different sintering temperatures, and with (failure, Pb) of scaffolds made from 13-93 bioactive- glass and GL1550 bioactive-glass powders are compared coating are related to mechanical properties to find the optimal heat treatment procedures and polymer

  13. Reaction of SiC{sub f}/SiC composites with a zinc borate glass

    SciTech Connect

    Lemoine, P.; Salvo, M.; Ferrais, M.; Montorsi, M. [Polytechnic di Torino (Italy). Material Science and Chemical Engineering Dept.; Scholz, H. [Joint Research Centre, Ispra (Italy). Inst. for Advanced Materials

    1995-06-01

    Two different types of SiC{sub f}/SiC composites were successfully joined using a zinc borate glass as a joining agent. The characterization of the joined specimens included XRD, DSC, DTA, SEM-EDS, macroporosimetry, and shear testing measurements. For both composites, the interfaces were continuous and crack-free, and a reaction occurred between the liquid glass and the composite`s surface. The large porosity of the chemical vapor deposited (CVI) composite allowed the glass to infiltrate the sandwich structure, the driving force being gaseous product pressurization and capillary surface forces.

  14. Structural, optical absorption and luminescence properties of Nd 3+ ions in NaO-NaF borate glasses

    NASA Astrophysics Data System (ADS)

    Karunakaran, R. T.; Marimuthu, K.; Arumugam, S.; Surendra Babu, S.; Leon-Luis, S. F.; Jayasankar, C. K.

    2010-07-01

    Structural and spectroscopic properties of neodymium doped sodium borate and fluoroborate glasses of composition (in mol%) (99 - X) B 2O 3 + XNa 2O + 1Nd 2O 3, X = 49.5, 39.5 and 29.5 and 49.5B 2O 3 + XNa 2O + (49.5 - X) NaF + 1Nd 2O 3, X = 0 and 24.75 have been investigated using XRD, FTIR, absorption and emission spectra and decay curve. The XRD of the glasses confirm their glassy nature and the FTIR spectra reveal the presence of BO 3 and BO 4 units along with the strong OH - groups in the glasses. The UV-vis-NIR absorption spectra were used to calculate the bonding parameters ( ?¯ and ?), to identify the ionic/covalent nature of the glasses. The spectral intensities have been calculated by using Judd-Ofelt analysis and inturn used to estimate radiative properties such as radiative transition probabilities, radiative lifetimes, branching ratios, peak stimulated emission cross-sections. Branching ratios and stimulated emission cross-sections show that the 4F 3/2 ? 4I 11/2 transition of the glasses under investigation has the strong emission around 1060 nm. The decay from the 4F 3/2 level of Nd 3+ ions is found to be single exponential. Multiphonon relaxation and quenching due to OH - groups play a governing role in the luminescence quenching of 4F 3/2 level of Nd 3+ ions in the titled glasses. The results obtained are compared with reports on similar glasses.

  15. Absorption and emission properties of Nd 3+ in lithium cesium mixed alkali borate glasses

    Microsoft Academic Search

    Y. C. Ratnakaram; A. Vijaya kumar; D. Tirupathi Naidu; R. P. S. Chakradhar

    2005-01-01

    Lithium cesium mixed alkali borate glasses of the composition 67B2O3·xLi2O·(32?x)Cs2O (where x=8, 12, 16, 20 and 24) containing 1mol% Nd2O3 were prepared by melt quenching. The absorption spectra of Nd3+ were studied from the experimental oscillator strengths and the Judd–Ofelt intensity parameters were obtained. The intensity parameters are used to determine the radiative decay rates (emission probabilities of transitions) (AT),

  16. Absorption and emission properties of Nd3+ in lithium cesium mixed alkali borate glasses

    Microsoft Academic Search

    Y. C. Ratnakaram; A. Vijaya Kumar; D. Tirupathi Naidu; R. P. S. Chakradhar

    2005-01-01

    Lithium cesium mixed alkali borate glasses of the composition 67B2O3·xLi2O·(32-x)Cs2O (where x=8, 12, 16, 20 and 24) containing 1 mol% Nd2O3 were prepared by melt quenching. The absorption spectra of Nd3+ were studied from the experimental oscillator strengths and the Judd Ofelt intensity parameters were obtained. The intensity parameters are used to determine the radiative decay rates (emission probabilities of

  17. Fourth-harmonic generation of picosecond glass laser pulses with cesium lithium borate crystals

    Microsoft Academic Search

    Lalit B. Sharma; H. Daido; Y. Kato; S. Nakai; T. Zhang; Y. Mori; T. Sasaki

    1996-01-01

    We report the fourth-harmonic generation of 1.5 ps, 1.053 ?m glass laser pulses, where group velocity mismatch plays a significant role, at intensities up to 100 GW\\/cm2 using newly developed crystal, cesium lithium borate (CsLiB6O10). Type-I doubler and type-I quadrupler were used in the fourth harmonic generation experimental scheme. Energy conversion efficiencies of 24% and 53% have been achieved for

  18. Compositional dependence of in-vitro bioactivity in sodium calcium borate glasses

    Microsoft Academic Search

    Manupriya; K. S. Thind; K. Singh; V. Kumar; G. Sharma; D. Singh

    2009-01-01

    Borate glasses with composition xCaO (100?x) B2O3 (20?x?50), where x is in mole percent) and 50CaO·45B2O3·5Na2O have been prepared using conventional melt quench technique. Samples were submerged in simulating body fluid solution (SBF) at 37°C for various periods of time. After storage the samples were analyzed in order to investigate if a surface layer of hydroxyl carbonate apatite layer (HCA

  19. Zinc Oxide in Borate Glass-Forming Systems

    Microsoft Academic Search

    N. M. Bobkova; S. A. Khot'ko

    2005-01-01

    Glasses based on the system ZnO - SrO - B2O3 with additional introduction of PbO, Al2O3, and Li2O are investigated; an elemental analysis of the heterogeneities is performed. The effect of ZnO on the physicochemical properties of glasses is considered. Fluxes with a decreased PbO content are developed.

  20. Fourth-harmonic generation of picosecond glass laser pulses with cesium lithium borate crystals

    SciTech Connect

    Sharma, L.B.; Daido, H.; Kato, Y.; Nakai, S. [Institute of Laser Engineering, Osaka University, 2-6, Yamada-Oka, Suita 565 (Japan)] [Institute of Laser Engineering, Osaka University, 2-6, Yamada-Oka, Suita 565 (Japan); Zhang, T. [Yamanashi University, Faculty of Engineering, 4-3-11 Takeda, Kofu, Yamanashi 400 (Japan)] [Yamanashi University, Faculty of Engineering, 4-3-11 Takeda, Kofu, Yamanashi 400 (Japan); Mori, Y.; Sasaki, T. [Department of Electrical Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565 (Japan)] [Department of Electrical Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565 (Japan)

    1996-12-01

    We report the fourth-harmonic generation of 1.5 ps, 1.053 {mu}m glass laser pulses, where group velocity mismatch plays a significant role, at intensities up to 100 GW/cm{sup 2} using newly developed crystal, cesium lithium borate (CsLiB{sub 6}O{sub 10}). Type-I doubler and type-I quadrupler were used in the fourth harmonic generation experimental scheme. Energy conversion efficiencies of 24{percent} and 53{percent} have been achieved for frequency quadrupling and doubling of the fundamental glass laser pulses, respectively. {copyright} {ital 1996 American Institute of Physics.}

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

    Microsoft Academic Search

    V. Simon; M. Spinu; R. Stefan

    2007-01-01

    Quaternary Ag2O-CaO-Bi2O3-B2O3 glasses and glassceramics are investigated with regard to release behaviour and local structure. The dissolution behaviour\\u000a in water and physiological serum shows that the cations are released rapidly or gradually and points out a multi-step process,\\u000a generally characterised by higher rates in water than in physiological serum. The structural effect of silver addition to\\u000a bismuth-borate glasses is observed

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

    SciTech Connect

    Gedam, R. S.; Ramteke, D. D. [Department of Applied physics, Visvesvaraya National Institute of Technology, Nagpur-440 010 (India)

    2012-06-05

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

  3. Structural, dielectric, and optical properties of yttrium calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Santos, Cristiane N.; De Sousa Meneses, Domingos; Echegut, Patrick; Neuville, Daniel R.; Hernandes, Antonio C.; Ibanez, Alain

    2009-04-01

    Structural and optical properties of stable glasses in the Y2O3-CaO-B2O3 system, containing the same Y/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy. Changes in optical functions with composition are associated with an increase in the number of non-bridging oxygen and to calcium/yttrium oxides content. Refractive indexes values (from 1.597 to 1.627 at ? =2 ?m) are in good agreement with those of the YCOB crystal, an indication that these glasses are potential candidates for optical applications due to their ease of shaping as large bulk samples or fibers.

  4. Physical, optical and electrical properties of calcium bismuth borate glasses

    Microsoft Academic Search

    S. Sanghi; S. Sindhu; A. Agarwal; V. P. Seth

    2004-01-01

    The variation in physical, optical and electrical properties has been investigated as a function of Bi2O3 content in 20CaO . x Bi2O3 . (80 - x )B-2 O-3 (0 less than or equal to x less than or equal to 60, in mol%) glasses. The samples were prepared by normal melt-quenching process, and the optical absorption and reflection spectra were

  5. Optical and structural characterization of yttrium calcium borate glasses

    Microsoft Academic Search

    Cristiane Santos; Domingos D. S. Meneses; Patrick Echegut; Daniel R. Neuville; Antonio C. Hernandes; Alain Ibanez

    2010-01-01

    Structural and optical properties of new stable glasses in the Y2O3 -- CaO -- B2O3 system, containing the same Y\\/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy [1]. We have obtained the optical functions using a dielectric function model and their evolution with composition are associated with an increase in the number of

  6. Vibrational excitations and elastic phases in Sodium Borate Glasses

    NASA Astrophysics Data System (ADS)

    Vignarooban, K.; Boolchand, P.; Micoulaut, M.

    2011-03-01

    Glass Transition temperatures (Tg s) and non-reversing enthalpy (? Hnr) at Tg of dry (Na 2 O)x (B2 O3)100-x glasses across the 0% x < 44% soda range are measured. Trends in ?Hnr (x) show a reversibility window in the 20% < x < 40% range, and fix the Intermediate Phase (IP). IR and Raman vibrational modes including Boson modes are also examined. At low x (<20%), the Raman active 808 cm-1 mode of boroxyl rings steadily lowers in scattering strength and red-shifts with increasing x, suggesting that the stressed-rigid quasi 2D network of B2O3 glassatx = 0 , steadilysoftenswithacharacteristicopticalelasticpower - law (< formula > < ? TeX . In the 26% < x < 40% range, a mode near 770 cm rapidly grows in strength and red shifts with increasing x with a power-law of characteristic of IPs observed earlier in other 3D covalent and ionic networks. In addition, many other modes are observed, some blue-shift, some red-shift and some remain unchanged with x. These data will be discussed in relation to glass structure evolution with composition. D.Novita et al. J. Phys. Condens. Matter 21, 205106 (2009) This work is supported by DMR- 08-53957.

  7. Optical assessment on a new self-frequency doubling crystal: neodymium-doped lanthanum calcium borate

    Microsoft Academic Search

    Rui Guo; Yicheng Wu; Peizhen Fu; Fangli Jing

    2005-01-01

    A new, to our knowledge, neodymium-doped lanthanum calcium borate crystal (Nd3+:La2CaB10O19, Nd:LCB) has been grown by the flux method. The spectroscopic parameters for Nd:LCB crystal have also been calculated based on Judd-Ofelt theory. The intensity parameters Omegat are Omega2=4.96×10-20 cm2, Omega4=3.94× 10-20 cm2, and Omega6=3.71×10-20 cm2. The radiative lifetime taur is 349 mus. The absorption band at 800 nm has

  8. Effect of Eu 3+-doped on the luminescence properties of zinc borate nanoparticles

    Microsoft Academic Search

    Yunhui Zheng; Yuning Qu; Yumei Tian; Chunguang Rong; Zichen Wang; Shengli Li; Xue Chen; Yuejia Ma

    2009-01-01

    Zinc borate (?-Zn(BO2)2) nanocrystalline powders doped with Eu3+ ions had been prepared using co-precipitation method. ?-Zn(BO2)2:Eu3+ had been characterized by X-ray diffraction, TEM, FT-IR and luminescence spectra. They showed different emissions of Eu3+ corresponding to different transitions which lied in the wavelength range from 530 to 850nm. One particular transition 5D0?7F2 which was centered at 615nm had been known as

  9. Structural, dielectric, and optical properties of yttrium calcium borate glasses

    Microsoft Academic Search

    Cristiane N. Santos; Domingos de Sousa Meneses; Patrick Echegut; Daniel R. Neuville; Antonio C. Hernandes; Alain Ibanez

    2009-01-01

    Structural and optical properties of stable glasses in the Y2O3-CaO-B2O3 system, containing the same Y\\/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy. Changes in optical functions with composition are associated with an increase in the number of non-bridging oxygen and to calcium\\/yttrium oxides content. Refractive indexes values (from 1.597 to 1.627 at lambda=2

  10. Structural, dielectric, and optical properties of yttrium calcium borate glasses

    Microsoft Academic Search

    Cristiane N. Santos; Domingos De Sousa Meneses; Patrick Echegut; Daniel R. Neuville; Antonio C. Hernandes; Alain Ibanez

    2009-01-01

    Structural and optical properties of stable glasses in the Y2O3–CaO–B2O3 system, containing the same Y\\/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy. Changes in optical functions with composition are associated with an increase in the number of non-bridging oxygen and to calcium\\/yttrium oxides content. Refractive indexes values (from 1.597 to 1.627 at ?=2

  11. Study of lithium borate glasses containing Bi2O3

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    The effect of Bi2O3 addition on the properties of 30Li2O:(70-x)B2O3:xBi2O3 (0?x?35 mol %) has been studied. Density and molar volume are increasing with Bi2O3 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 Bi2O3 content which is related to the structural changes.

  12. Physical, optical and electrical properties of calcium bismuth borate glasses

    NASA Astrophysics Data System (ADS)

    Sanghi, S.; Sindhu, S.; Agarwal, A.; Seth, V. P.

    2004-06-01

    The variation in physical, optical and electrical properties has been investigated as a function of Bi2O3 content in 20CaO . x Bi2O3 . (80 - x )B-2 O-3 (0 less than or equal to x less than or equal to 60, in mol%) glasses. The samples were prepared by normal melt-quenching process, and the optical absorption and reflection spectra were recorded in the wavelength range of 400-950 nm. The fundamental absorption edge has been identified from the optical absorption spectra. The optical band gap, E-g , for indirect allowed and indirect forbidden transitions has been determined from the available theories and its value lies between 1.80-2.37 eV and 1.08-2.19 eV, respectively. The theoretical fitting of the optical absorption indicates that the present glass system behaves as an indirect gap semiconductor. The origin of the Urbach energy, Delta E , has been associated with the phonon-assisted indirect transitions. The refractive index and optical dielectric constant have been evaluated from the reflection spectra. The density and molar volume are found to depend on the molar concentration of Bi2O3 . The values of DC electrical conductivity have been measured from 373 to 623 K and the activation energy has been calculated. Theoretical optical basicity has been reported as a function of the Bi2O3 content. The variations have been discussed in terms of structural changes.

  13. Gadolinium zinc borate glass-based low temperature Co-fired ceramics

    Microsoft Academic Search

    Yeon Hwa Jo; Deuk Ho Yeon; Bhaskar C. Mohanty; Yong Soo Cho

    2008-01-01

    New microwave materials based on a gadolinium zinc borate (20ZnO?20Gd2O3?60B2O3) glass with typical Al2O3 filler have been investigated as a dielectric candidate for low temperature co-fired ceramic (LTCC) applications. The experimental\\u000a parameters, such as filler contents and firing temperature, were found to affect seriously densification, crystallization\\u000a and microwave dielectric properties. The presence of ZnAl2O4 and GdBO3 phases with an unexpected

  14. Effect of pyrophosphate ions on the conversion of calcium–lithium–borate glass to hydroxyapatite in aqueous phosphate solution

    Microsoft Academic Search

    Hailuo Fu; Mohamed N. Rahaman; Delbert E. Day; Wenhai Huang

    2010-01-01

    The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the\\u000a bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this\\u000a work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calcium–lithium–borate\\u000a glass

  15. 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

  16. Coordination and ion-ion interactions of chromium centers in alkaline earth zinc borate glasses probed by electron paramagnetic resonance and optical spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    Electron paramagnetic resonance (EPR), optical absorption and FT-IR studies have been carried out on chromium ions incorporated in alkaline earth zinc borate glasses. The EPR spectra exhibit two resonance signals with effective g values at g ? 1.99 and ?1.97. The resonance signal at g ? 1.99 is attributed to the contribution from both the exchange coupled Cr3+-Cr3+ ion pairs and the isolated Cr3+ ions and the resonance signal at g ? 1.97 is due to Cr5+ ions. The paramagnetic susceptibility (?) was calculated from the EPR data at various (123-303 K) temperatures and the Curie temperature (?p) was calculated from the 1/?-T graph. The optical absorption spectra exhibit three bands at ˜360 nm, ˜440 nm and a broad band at ˜615 nm characteristic of Cr3+ ions in an octahedral symmetry. From the observed band positions, the crystal-field splitting parameter Dq and the Racah parameters (B and C) have been evaluated. From the ultraviolet edges, the optical band gap energies (Eopt) and Urbach energy (?E) are calculated. The theoretical optical basicity (?th) of these glasses has also been evaluated. Chromium ions doped alkaline earth zinc borate glasses show BO3 and BO4 structural units in the FT-IR studies.

  17. Optical properties of cerium doped oxyfluoroborate glass.

    PubMed

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

    2013-06-01

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

  18. Raman scattering study of barium borate glasses and melts

    NASA Astrophysics Data System (ADS)

    Osipov, Armenak A.; Osipova, Leyla M.

    2013-07-01

    Glasses and melts of xBaO-(100-x)B2O3 (x=20, 25, 30, 35, 40, 45, 50, 55, 60 and 67 mol%) composition have been prepared and studied using high-temperature Raman spectroscopy. It was shown that the structure of the glassy and molten samples with relatively low concentrations of barium oxide (x=20-35 mol%) consists of [B?4]- charged tetrahedra (? is a bridging oxygen atom), B?2O- asymmetric triangles (O- is a non-bridging oxygen atom) and B?3 neutral units. The concentration of [B?4]- tetrahedra (N4) monotonously decreases with increasing BaO content in the melts structure, whereas N4 demonstrates a maximum at x?40 mol% in the glassy samples. B?O22- pyroborate units appear at x?40 mol%, and BO33- orthoborate anions are also formed in the melts structure when x=60 and 67 mol%. The dominant mechanisms for the structural reorganizations generated by changes in temperature depend on the melt composition. The changes in the short range order (SRO) structures can be described by the [B?4]-?B?2O- isomerization reaction at 2550 is most likely described by the 2B?2O?B?O22-+B?3 disproportionation reaction. In both cases, the equilibrium shifts to the right with an increase in temperature. Significant changes in the local structures of melts with a low concentration of barium oxide (x?20 mol%) were not found.

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

    PubMed Central

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

    2013-01-01

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

  20. 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.

  1. Silicate and borate glasses as composite fillers: a bioactivity and biocompatibility study.

    PubMed

    Lopes, P P; Ferreira, B J M Leite; Gomes, P S; Correia, R N; Fernandes, M H; Fernandes, M H V

    2011-06-01

    Composites filled with a silicate glass (CSi) and a new borate glass (CB) were developed and compared in terms of their in vitro behaviour both in acellular and cellular media. Acellular tests were carried out in SBF and the composites were characterized by SEM-EDS, XRD and ICP. Biocompatibility studies were investigated by in vitro cell culture with MG-63 osteoblast-like and human bone marrow cells. The growth of spherical calcium phosphate aggregates was observed in acellular medium on all composite surfaces indicating that these materials became potentially bioactive. The biological assessment resulted in a dissimilar behavior of the composites. The CSi demonstrated an inductive effect on the proliferation of cells. The cells showed a normal morphology and high growth rate when compared to standard culture plates. Contrarily, inhibition of cell proliferation occurred in the CB probably due to its high degradation rate, leading to high B and Mg ionic concentration in the cell culture medium. PMID:21556978

  2. Effect of the sintering temperature on the structural and magnetic parameters of strontium ferrites doped with kaolin and barium borate

    Microsoft Academic Search

    V. P. Pashchenko; O. A. Kostyagina; S. M. Lisitsyn; A. K. Prokopenko; L. Y. Selivanova; D. Y. Serebro

    1986-01-01

    This paper presents the results of studies of the effect of the sintering temperature of strontium ferrites (doped with 1.2 mass % kaolin and barium borate) on their properties. The fine crystalline structure of anisotropic and demagnetized strontium ferrites doped with kaolin was studied with the help of the Moessbauer effect. Fe-57 nuclei, occupying 4f2 and 2a octahedral positions, respectively,

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

    SciTech Connect

    Matsuda, Yu; Ike, Yuji [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8571 (Japan); Matsui, Chihiro [College of Engineering Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8573 (Japan); Kodama, Masao [Department of Applied Chemistry, Sojo University, Kumamoto, 860-0082 (Japan); Kojima, Seiji [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8571 (Japan); College of Engineering Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8573 (Japan)

    2006-05-05

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

  4. Optical and FTIR spectra of NdF3-doped borophosphate glasses and effect of gamma irradiation

    NASA Astrophysics Data System (ADS)

    ElBatal, F. H.; Ibrahim, S.; Abdelghany, A. M.

    2012-12-01

    UV-visible, FTIR absorption spectra of some prepared undoped and NdF3-doped borophosphate glasses with varying dopant contents were studied before and after gamma irradiation. The base undoped borophosphate glass exhibits strong UV absorption which is related to the presence of unavoidable trace iron impurities within the chemicals used for the preparation of such glass. NdF3-doped samples show characteristic bands specifically at high concentration which are attributed to the Nd3+ ions. Gamma irradiation on the undoped borophosphate glass causes no obvious induced defects. On the other hand, the low NdF3 content glass produces extended UV absorption together with the resolution of an extra induced visible at about 500 nm. On increasing the NdF3 content, gamma irradiation retains the characteristic bands due to Nd3+ ions. Infrared absorption spectra of undoped and NdF3-doped glasses reveal characteristic IR vibrational bands due to the combination of both phosphate and borate groups (BO3 and BO4) with the first phosphate partner dominating in response to the high percent (50 mol%). The introduction of NdF3 within the dopant level (1.5-6%) produces no distinct effect on the FTIR spectra. Gamma irradiation is observed to cause no obvious effects on the FTIR spectra which is related to the stability of mixed phosphate and borate units causing the compactness and resistance towards gamma irradiation.

  5. Sensitized red luminescence from Bi 3+ co-doped Eu 3+: ZnO-B 2O 3 glasses

    NASA Astrophysics Data System (ADS)

    Sontakke, Atul D.; Tarafder, Anal; Biswas, Kaushik; Annapurna, K.

    2009-11-01

    Photoluminescence properties of Bi 3+ co-doped Eu 3+ containing zinc borate glasses have been investigated and the results are reported here. Bright red emission due to a dominant electric dipole transition 5D 0? 7F 2 of the Eu 3+ ions has been observed from these glasses. The nature of Stark components from the measured fluorescence transitions of Eu 3+ ions reveal that the rare earth ions could take the lattice sites of C s or lower point symmetry in the zinc borate glass hosts. The significant enhancement of Eu 3+ emission intensity by 346 nm excitation ( 1S 0? 3P 1 of Bi 3+ ions) elucidates the sensitization effect of co-dopant. The energy transfer mechanism between sensitizer (Bi 3+) and activator (Eu 3+) ions has been explained.

  6. A study of electron paramagnetic resonance and optical absorption spectra of VO 2+ ions in alkali calcium borate glasses

    Microsoft Academic Search

    R. P. Sreekanth Chakradhar; A. Murali; J. Lakshmana Rao

    2000-01-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of VO2+ ions in different alkali calcium borate glasses have been studied. The spin-Hamiltonian parameters (g and A), bonding parameter (?2?2), Fermi contact interaction parameter (k) and crystal field parameters have been evaluated. The values of spin-Hamiltonian parameters confirm that vanadyl ions are present in the glasses as VO2+ molecular ions in

  7. A study of electron paramagnetic resonance and optical absorption spectra of VO2+ ions in alkali calcium borate glasses

    Microsoft Academic Search

    R. P. Sreekanth Chakradhar; A. Murali; J. L. Rao

    2000-01-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of VO2+ ions in different alkali calcium borate glasses have been studied. The spin-Hamiltonian parameters (\\/g and \\/A), bonding parameter (beta2*2), Fermi contact interaction parameter (\\/k) and crystal field parameters have been evaluated. The values of spin-Hamiltonian parameters confirm that vanadyl ions are present in the glasses as VO2+ molecular ions in

  8. Mössbauer and X-ray photoelectron spectroscopic studies of heat-treated calcium borate glasses containing iron

    Microsoft Academic Search

    M. J. Tricker; J. M. Thomas; M. H. Omar; A. Osman; A. Bishay

    1974-01-01

    57Fe Mössbauer and X-ray photoelectron spectroscopic studies have been carried out on a number of iron-containing calcium borate glasses which show large changes in d.c. conductivity upon annealing. The Mössbauer spectra of the unannealed glass samples are compatible with the presence of predominantly ferric iron in a six-co-ordinate oxygen environment. Upon annealing a partial ordering of the glassy phase is

  9. Characterization of lithium borate–bismuth tungstate glasses and glass-ceramics by impedance spectroscopy

    Microsoft Academic Search

    G Senthil Murugan; K. B. R Varma

    2001-01-01

    Transparent glasses in the system (1?x)Li2B4O7–xBi2WO6 (0?x?0.35) were prepared via melt quenching technique. Differential thermal analysis was employed to characterize the as-quenched glasses. Glass-ceramics with high optical transparency were obtained by controlled heat-treatment of the glasses at 720 K for 6 h. The amorphous nature of the as-quenched glass and crystallinity of glass-ceramics were confirmed by X-ray powder diffraction studies.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

  11. Luminescence and spectral hole burning of Sm 2+ doped in Li 2O–SrO–B 2O 3 glass-ceramics

    Microsoft Academic Search

    Chuanfang Jiang; Yanlin Huang; Kiwan Jang; Hyo Jin Seo

    2009-01-01

    The Sm3+-doped alkali strontium borate glass-ceramics were obtained by heating of the as-made glasses in air, where Sm3+ ions were reduced to Sm2+ ions. The XRD, optical absorption spectra and luminescence of Sm3+ and Sm2+ ions were investigated. The excitation spectra of the 7F0?5D0 transition were measured in the region of 7F0?5D1 transition, where spectral holes were burnt within two

  12. 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.

  13. 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.

  14. Effect of host glass on the optical absorption properties of Nd3+, Sm3+, and Dy3+ in lead borate glasses

    Microsoft Academic Search

    M. B. Saisudha; J. Ramakrishna

    1996-01-01

    The effect of host glass composition on the optical absorption spectra of Nd3+, Sm3+, and Dy3+ in lead borate glasses, with PbO contents varying from 30 to 70 mol %, has been analyzed using Judd-Ofelt theory and the compositional dependence has been determined for the hypersensitive bands. Judd-Ofelt intensity parameters Omegat (t=2,4,6), and the radiative transition probabilities. The variation of

  15. Rare earth-doped glass microbarcodes

    PubMed Central

    Dejneka, Matthew J.; Streltsov, Alexander; Pal, Santona; Frutos, Anthony G.; Powell, Christy L.; Yost, Kevin; Yuen, Po Ki; Müller, Uwe; Lahiri, Joydeep

    2003-01-01

    The development of ultraminiaturized identification tags has applications in fields ranging from advanced biotechnology to security. This paper describes micrometer-sized glass barcodes containing a pattern of different fluorescent materials that are easily identified by using a UV lamp and an optical microscope. A model DNA hybridization assay using these “microbarcodes” is described. Rare earth-doped glasses were chosen because of their narrow emission bands, high quantum efficiencies, noninterference with common fluorescent labels, and inertness to most organic and aqueous solvents. These properties and the large number (>1 million) of possible combinations of these microbarcodes make them attractive for use in multiplexed bioassays and general encoding. PMID:12515864

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

    Microsoft Academic Search

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

    2010-01-01

    The objective of this work was to evaluate borate bioactive glass scaffolds (with a composition in the system Na2O–K2O–MgO–CaO–B2O3–P2O5) as devices for the release of the drug Vancomycin in the treatment of bone infection. A solution of ammonium phosphate,\\u000a with or without dissolved Vancomycin, was used to bond borate glass particles into the shape of pellets. The in vitro degradation

  17. Thermoluminescence properties of CaO-B2O3 glass system doped with GeO2

    NASA Astrophysics Data System (ADS)

    Tengku Kamarul Bahri, T. N. H.; Wagiran, H.; Hussin, R.; Hossain, I.; Kadni, T.

    2014-09-01

    The aim of this study is to investigate the thermoluminescence properties of germanium doped calcium borate glass for thermoluminescence dosimeter used. Glasses with composition (30-x) CaO-70B2O3: xGeO2 where x=0.1, 0.2, 0.3, 0.4 and 0.5 mol% were prepared using a melt-quenching method. The glasses were irradiated to 60Co gamma ray with doses ranging from 0.5 Gy to 4.0 Gy. The amorphous phases were identified for all glass samples. The glow curves were analyzed to determine various characterizations of a thermoluminescence dosimeter of the glass. It was found that the sample with a concentration of 0.1 mol% GeO2 has the best thermoluminescence characteristics such as linearity, sensitivity, fading characteristic, minimum detectable dose and effective atomic number. The results clearly showed that germanium doped calcium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  18. Optical assessment on a new self-frequency doubling crystal: neodymium-doped lanthanum calcium borate

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Wu, Yicheng; Fu, Peizhen; Jing, Fangli

    2005-04-01

    A new, to our knowledge, neodymium-doped lanthanum calcium borate crystal (Nd3+:La2CaB10O19, Nd:LCB) has been grown by the flux method. The spectroscopic parameters for Nd:LCB crystal have also been calculated based on Judd-Ofelt theory. The intensity parameters ?t are ?2=4.96×10-20 cm2, ?4=3.94× 10-20 cm2, and ?6=3.71×10-20 cm2. The radiative lifetime ?r is 349 ?s. The absorption band at 800 nm has a FWHM of 12 nm. The absorption cross section is ?a=2.40×10-20 cm2, and the emission cross sections at 1070 nm are ?X=3.02×10-19 cm2, ?Y=2.33×10-19 cm2, and ?Z=2.68×10-19 cm2. The measured fluorescence lifetime ?f is 64 ?s, and the quantum efficiency ? is 18.3%. In comparison with other Nd-doped laser crystals, the calculated parameters show that Nd:LCB crystal satisfies the fundamental spectral condition for laser emission.

  19. Absorption and luminescence spectroscopy of Nd 3+ and Er 3+ in a zinc borate glass

    NASA Astrophysics Data System (ADS)

    Pozza, Giorgio; Ajò, David; Bettinelli, Marco; Speghini, Adolfo; Casarin, Maurizio

    1996-02-01

    4ZnO · 3B 2O 3 glasses doped with Nd 3+ and Er 3+ were investigated by optical spectroscopy. Emission transition probabilities, radiative life-times and fluorescence branching ratios for several excited states of the Nd 3+ and Er 3+ ions were estimated from the room temperature absorption spectra. The stimulated emission cross sections ?p for the near infrared laser transitions of Nd 3+ and Er 3+ were obtained from laser-excited luminescence spectra. The values of ?p are comparable with those shown by glasses used in solid state laser applications.

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

    SciTech Connect

    Borodi, G. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Pascuta, P.; Bosca, M.; Pop, V. [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania)] [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania); Stefan, R. [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania)] [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania); Tetean, R. [Babes-Bolyai University, 1 Mihail Kogalniceanu, Faculty of Physics, 400084 Cluj Napoca (Romania)] [Babes-Bolyai University, 1 Mihail Kogalniceanu, Faculty of Physics, 400084 Cluj Napoca (Romania); Radulescu, D. [University of Medicine and Pharmacy Iuliu Hatieganu, 8 Victor Babes, 400012 Cluj-Napoca (Romania)] [University of Medicine and Pharmacy Iuliu Hatieganu, 8 Victor Babes, 400012 Cluj-Napoca (Romania)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    Glasses of the system (Er2O3)x?(B2O3)(60-x)?(ZnO)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 Er3+ ions and decrease with the increasing of Er2O3 content. The decrease is more pronounced in heat treated samples than untreated ones.

  2. Site selective spectroscopy and crystal field analysis of Eu3 + doped lanthanum-calcium-zirconium-silicon borate

    Microsoft Academic Search

    J. A. Capobianco; P. P. Proulx; N. Raspa; D. J. Simkin; D. Krashkevich

    1989-01-01

    The fluorescence of Eu3+ doped lanthanum–calcium–zirconium–silicon borate ceramic was studied at 77 and 300 K using laser excited site selective spectroscopy. The fluorescence spectrum excited at 514.532 nm reveals the presence of three distinct sites for Eu3+. The sites were assigned to Eu3+ substituting for lanthanum in a ninefold coordination site in LaBO3 and Eu3+ substituting for Ca2+ in six-

  3. Absorption and luminescence spectroscopy of Nd 3+ and Er 3+ in a zinc borate glass

    Microsoft Academic Search

    Maurizio Casarin

    1996-01-01

    4ZnO · 3B2O3 glasses doped with Nd3+ and Er3+ were investigated by optical spectroscopy. Emission transition probabilities, radiative life-times and fluorescence branching ratios for several excited states of the Nd3+ and Er3+ ions were estimated from the room temperature absorption spectra. The stimulated emission cross sections ?p for the near infrared laser transitions of Nd3+ and Er3+ were obtained from

  4. Optical spectroscopy of Eu 3+ ions in lithium borate and lithium fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Babu, P.; Jayasankar, C. K.

    2000-05-01

    Optical absorption, excitation and emission spectra of Eu 3+ ions in lithium borate and lithium fluoroborate glasses have been investigated. Judd-Ofelt intensity parameters are derived from the integrated absorption spectra and also from the emission spectra under various constraints. The relative merits of thermal correction to the oscillator strengths of the transitions originating from the ground state ( 7F0) of Eu 3+ ion observed in the absorption spectra have been discussed. The Judd-Ofelt parameters obtained from the emission spectra have been used to calculate the total spontaneous emission probabilities ( A), lifetimes ( ?R) and branching ratios ( ?R) for eight excited levels that include, 5K6, 3P0, 5H3, 5L7, 5D3, 5D2, 5D1 and 5D0. The predicted values of ?R and ?R are compared with the measured values for 5D0 level. The stimulated emission cross-sections ( ? ( ?p)) are also evaluated for the 5D0? 7FJ and 5D1? 7FJ transitions. The variation of optical properties with compositional changes of lithium oxide and lithium fluoride contents in the glasses are discussed and compared with similar results.

  5. Optical absorption of Nd 3+, Sm 3+ and Dy 3+ in bismuth borate glasses with large radiative transition probabilities

    Microsoft Academic Search

    M. B Saisudha; J. Ramakrishna

    2002-01-01

    This paper reports on the optical properties of Nd3+, Sm3+ and Dy3+ in bismuth borate glasses, with Bi2O3 content varying from 30 to 60 mol%. The variation of the optical properties with composition plays a dominant role in determining a good laser host material. The variation of the Judd–Ofelt intensity parameters ?t (t=2,4,6) and the radiative transition probabilities and the

  6. The effect of V 2O 5 on alkaline earth zinc borate glasses studied by EPR and optical absorption

    Microsoft Academic Search

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

    10wt% SrO:30wt% ZnO:60wt% B2O3 incorporated with different vanadyl concentrations were studied by means of electron paramagnetic resonance (EPR) and optical absorption techniques. The spin-Hamiltonian parameters (g and A), bonding parameters (?2 and ?2?2) and Fermi contact interaction parameter K have been calculated. The values of spin-Hamiltonian parameters indicate that the VO2+ ions in strontium zinc borate glasses were present in

  7. Physical and structural properties of Nd3+ doped BaO-ZnO-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Nanda, Kirti; Kundu, R. S.; Punia, R.; Parmar, R.; Kishore, N.

    2013-06-01

    Nd3+ doped Barium-Zinc-Borate glasses with composition xNd2O3-(100-x)[0.1BaO-0.4ZnO-0.5B2O3];x = 0,0.5,1.0,1.5,2.0 have been prepared by melt-quenching method. X-Ray Diffractogram of the synthesized glass samples confirms the amorphous nature. The physical properties i.e. density and molar volume have been measured and both increases with increase in Nd3+ content. Glass transition temperature have been measured using DSC and found to be increase with Nd3+ content shows good thermal stability. Analysis of FTIR spectra estimate the presence of tetrahedral coordination of Zn (i.e. ZnO4) in synthesized glasses. The basic structural units [BO3] and [BO4] are observed in glasses under study.

  8. The Faraday effect and magneto-optical figure of merit in the visible region for lithium borate glasses containing ?

    Microsoft Academic Search

    Katsuhisa Tanaka; Naoki Tatehata; Koji Fujita; Kazuyuki Hirao; Naohiro Soga

    1998-01-01

    Faraday-effect measurements have been carried out at room temperature for 0022-3727\\/31\\/19\\/035\\/img2-containing lithium borate glasses to evaluate the magneto-optical figure of merit in the wavelength range of 350-850 nm. The magneto-optical figure of merit tends to increase with decreasing wavelength except for the range within which absorption bands due to the 4f-4f transitions are observed. Glasses with low 0022-3727\\/31\\/19\\/035\\/img3 content and

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

    NASA Astrophysics Data System (ADS)

    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 Mo6+ and Mo5+ ions. The base undoped borophosphate glass shows retardation effect towards gamma irradiation. Gamma irradiation produces marked changes in the UV-visible spectra of Mosbnd 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.

  10. 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

  11. Photosensitivity of rare-earth-doped glasses

    NASA Astrophysics Data System (ADS)

    Williams, Glen M.; Dutt, David A.; Ruller, Jacqueline A.; Griscom, David L.; Jewell, John M.; Crahan, Kathleen K.; Friebele, E. J.

    1993-12-01

    Rare earth-doped glasses exhibit high initial photosensitivity but their response saturates at relatively modest values of (Delta) n (approximately 5 X 10-7), which greatly limits their usefulness for device applications. In the context of our model, saturation results from either exhaustion of photosensitive rare earth sites, trap sites, or through competition between two photon creation and one photon bleaching processes. In this paper we report the results of new experiments designed to further elucidate the photosensitivity process with specific emphasis on the saturation mechanisms(s). Based on these new experimental results we present a refinement of our earlier model.

  12. Pr-doped lead fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Pisarska, Joanna; Dominiak-Dzik, Gra?yna; Ryba-Romanowski, Witold; Pisarski, Wojciech A.

    2006-10-01

    Structural and optical behavior of Pr-doped lead fluoroborate glass has been investigated. Incorporation of PbF II results in structural and optical changes around Pr 3+ ions and surrounding ligands, which were analyzed using X-ray diffraction, Raman, IR and luminescence spectroscopy. Shift of spectral lines has been observed, when lead oxide is totally substituted by lead fluoride in glass composition. Luminescence corresponding to the 1D II - 3H 4 transition of Pr 3+ ions has been detected. The peak luminescence wavelength is changed from 604 nm to 599 nm and linewidth decreases from 23.5 nm to 18 nm, whereas the infrared bands due to the B-O vibrations are shifted to lower frequency region.

  13. A study of electron paramagnetic resonance and optical absorption spectra of VO 2+ ions in alkali calcium borate glasses

    NASA Astrophysics Data System (ADS)

    Sreekanth Chakradhar, R. P.; Murali, A.; Rao, J. Lakshmana

    2000-12-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of VO 2+ ions in different alkali calcium borate glasses have been studied. The spin-Hamiltonian parameters ( g and A), bonding parameter ( ?2?2), Fermi contact interaction parameter ( k) and crystal field parameters have been evaluated. The values of spin-Hamiltonian parameters confirm that vanadyl ions are present in the glasses as VO 2+ molecular ions in an octahedral site with a tetragonal compression. At high concentrations of vanadyl ions, the intensity of the EPR resonance signals decreases which has been attributed to the change of oxidation state from V 4+ to V 5+. The EPR spectra have also been studied at different temperatures for VO 2+ ions in sodium calcium borate glasses. The spin-Hamiltonian parameters are found to be independent of temperature. The magnetic susceptibility ? is calculated from the EPR data. It is observed that as the temperature is decreased the susceptibility increases in accordance with the Curie's law. The theoretical values of optical basicity (? th) of glasses have been evaluated. The optical absorption spectrum exhibits two bands characteristic of VO 2+ ions in tetragonal symmetry. The two bands have been assigned to the transitions 2B2 g? 2B1 g and 2B2 g? 2Eg in the decreasing order of energy. The octahedral field parameter (Dq) and the tetragonal field parameters Ds and Dt have been evaluated.

  14. The effect of V 2O 5 on alkaline earth zinc borate glasses studied by EPR and optical absorption

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    10 wt% SrO:30 wt% ZnO:60 wt% B 2O 3 incorporated with different vanadyl concentrations were studied by means of electron paramagnetic resonance (EPR) and optical absorption techniques. The spin-Hamiltonian parameters ( g and A), bonding parameters ( ?2 and ?2?2) and Fermi contact interaction parameter K have been calculated. The values of spin-Hamiltonian parameters indicate that the VO 2+ ions in strontium zinc borate glasses were present in octahedral sites with tetragonal compression. The spin concentration ( N) participating in resonance was calculated as a function of temperature (93-273 K) for strontium zinc borate glass sample containing 0.9 wt% of VO 2+ ions and the activation energy ( Ea) was calculated. From the EPR data, the paramagnetic susceptibility ( ?) was calculated at various temperatures and the Curie constant ( C) was evaluated from the 1/ ?- T graph. The optical absorption spectra of VO 2+ ions in these glasses show two bands corresponding to the transitions 2B 2g ? 2B 1g and 2B 2g ? 2E g in the order of decreasing energy respectively. The optical band gap energies ( Eopt) and Urbach energy (? E) have been determined from their ultraviolet edges. The theoretical values of optical basicity ( ?th) of these glasses have also been evaluated.

  15. Energy transfer in silver and cerium co-doped glass

    NASA Astrophysics Data System (ADS)

    Kim, Taehong; Kim, Daejin; Jang, Wooyoung; Lim, Ki-Soo; Lee, Sunkyun; Cho, Yong-Hoon

    The spectroscopic characterizations of sodium borate glasses codoped with Ce3+ and Ag+ prepared by melt quench method are done using absorption, excitation and emission spectra. The nonradiative energy transfer between Ag+ and Ce3+ ions process is observed. With fs-laser irradiation, we formed silver aggregates and studied efficient resonant energy transfer from Ce3+ ions to silver aggregates by analyzing the emission of Ce3+ ions and the absorption of the silver aggregates.

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

    PubMed

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

    2007-02-01

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

  17. Optical absorption of Nd 3+, Sm 3+ and Dy 3+ in bismuth borate glasses with large radiative transition probabilities

    NASA Astrophysics Data System (ADS)

    Saisudha, M. B.; Ramakrishna, J.

    2002-01-01

    This paper reports on the optical properties of Nd 3+, Sm 3+ and Dy 3+ in bismuth borate glasses, with Bi 2O 3 content varying from 30 to 60 mol%. The variation of the optical properties with composition plays a dominant role in determining a good laser host material. The variation of the Judd-Ofelt intensity parameters ? t ( t=2,4,6) and the radiative transition probabilities and the hypersensitive band positions, with composition, have been discussed in detail. The changes in position and intensity parameters of the transitions in the optical absorption spectra are correlated to the structural changes in the host glass matrix. The variation of ? 2 with Bi 2O 3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth-oxygen (R-O) covalency, whereas the variation of ? 6 strongly depends on nephlauxetic effect. The shift of the hypersensitive band shows that the covalency of the R-O bond increases with increase of Bi 2O 3 content, due to increased interaction between the rare earth ions and the non-bridging oxygens. The radiative transition probabilities of the rare earth ions are large in bismuth borate glasses, suggesting their suitability for laser applications.

  18. 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.

  19. 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

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  2. Gamma rays interaction with copper doped lithium phosphate glasses

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  3. Molecular dynamics simulations of rare-earth-doped glasses

    Microsoft Academic Search

    S. Chaussedent; V. Teboul; A. Monteil

    2003-01-01

    In the recent years the use of the molecular dynamics technique has become very common in the study of glass. The purpose of the present paper is to focus on recent advancements on the use of this method to investigate rare-earth-doped glasses. We report an overview of the use of simulations to study their specific structural features and luminescence properties.

  4. 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

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

    NASA Astrophysics Data System (ADS)

    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 200-900 nm 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.

  6. Recent developments on rare-earth-doped glasses

    Microsoft Academic Search

    Jean-Luc Adam; Jacques Lucas; Shibin Jiang

    1997-01-01

    Recent developments in rare-earth (RE)-doped glasses are presented. The paper includes an overview of UV, blue, green and IR fluoride glass fiber lasers, together with the performances of RE optical amplifiers of the first, second, and third telecommunication windows. Spectroscopic results concerning low-photon-energy sulfide and chloro-fluoride glasses for 1.3 micrometers amplification are discussed. A special section is devoted to phosphate

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

    PubMed

    Jo, Sinae; Kang, Seunggu

    2013-11-01

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

  8. Luminescence and spectral hole burning of Sm(2+) doped in Li(2)O-SrO-B(2)O(3) glass-ceramics.

    PubMed

    Jiang, Chuanfang; Huang, Yanlin; Park, Seongtae; Jang, Kiwan; Seo, Hyo Jin

    2009-03-01

    The Sm(3+)-doped alkali strontium borate glass-ceramics were obtained by heating of the as-made glasses in air, where Sm(3+) ions were reduced to Sm(2+) ions. The XRD, optical absorption spectra and luminescence of Sm(3+) and Sm(2+) ions were investigated. The excitation spectra of the (7)F(0)-->(5)D(0) transition were measured in the region of (7)F(0)-->(5)D(1) transition, where spectral holes were burnt within two of the Stark split (5)D(1) bands. The Sm(2+) ions doped glass ceramics exhibit the persistent spectral hole burning at room temperature. The hole depth, which are burned by the DCM dye laser, are about 40% of the total intensity, respectively. It is concluded that the dominant burning mechanism is a photoionization of electron trapping at a site other than Sm(3+) ions because of the absence of an antihole around the burned hole. PMID:19058997

  9. 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.

  10. Advances in laser cooling of thulium-doped glass

    Microsoft Academic Search

    C. W. Hoyt; M. P. Hasselbeck; M. Sheik-Bahae; R. I. Epstein; S. Greenfield; J. Thiede; J. Distel; J. Valencia

    2003-01-01

    Recent developments in cooling thulium-doped heavy-metal fluoride glass are presented. Thulium-doped fluorozirconate (ZBLANP) is cooled to 19 K below ambient with a multiple-pass pump scheme. This represents over an order of magnitude increase from the previously reported single-pass geometry. The results agree with a simple model for anti-Stokes fluorescence cooling that includes considerations of quantum efficiency and parasitic heating mechanisms.

  11. EXAFS study of a “mixed-alkali” type effect in sodium-calcium borate glass

    Microsoft Academic Search

    H. C. Brook; A. V. Chadwick; J. F. W. Mosslemans; G. N. Greaves

    1999-01-01

    Replacement of one alkali in a glass by another is known to have a profound effect on many physical properties in that glass. In the case of electrical conductivity, there is a nonlinear variation between the values of the two relevant single-alkali glasses, with a minimum at some mixed composition. This is referred to as the mixed-alkali effect (MAE), and

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

    SciTech Connect

    Ramachari, D. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Rama Moorthy, L., E-mail: lrmphysics@yahoo.co.in [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Department of Physics, Chadalawada Ramanamma Engineering College, Renigunta Road, Tirupati 517506 (India); Jayasankar, C.K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1992-11-01

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

  14. Effects of halogen substitutions on the formation of copper colloids by hydrogen reduction in sodium borate glasses

    NASA Astrophysics Data System (ADS)

    Edson, Daniel Lee

    2002-01-01

    The substitution of small amounts of halogens (< 1 mol%) for oxygen in sodium borate glasses with 10 to 35 mol% soda that contain 0.1 or 0.2 wt% CuO dramatically influences the ligand environment around copper in these glasses and the formation of copper colloids during hydrogen treatment near Tg. The suppression of copper colloid formation in glasses that contain halogen ions has not previously been reported. The interaction of halogen ions and copper depends on the identity of the halogen ion, the ratio of the molar concentrations halogen to copper ions and the soda content of the glass. The heavier halogen ions, Cl, Br and I, preferentially associate with copper ions in the melt. Four bromine ions associate with each cupric ion, reducing it to the cuprous state. The reduction power of the ions increases in the order Cl- < Br- < I-. Cl, Br and I associate with cupric ions in combination with oxygen ions in the glass. These mixed anion complexes, which probably contain multiple halogen ions, give rise to intense charge transfer absorption bands in the UV-Vis spectra which cause a color change in the glass. The concentration of the mixed anion complexes is very small and depends on the ratio of halogen to copper. The reduction of cupric ions has been separated from the growth of copper colloids during hydrogen reduction through use of the ESR. The reduction of cupric ions by hydrogen is described by the tarnishing model. The presence of Cl, Br and I completely prevents the formation of copper colloids during hydrogen reduction near Tg. CuBr nanoparticles form in glasses with ratios of Br:Cu of 1:1 or 2:1. Support for the view that cuprous ions are the diffusing species in these glasses following hydrogen reduction is presented, with a requirement that hydrogen be present at the growing nuclei to further reduce the ion to the atomic state. Bonding between mobile cuprous ions and halogen ions is suggested to slow or prevent the formation of copper colloids and the growth of CuBr nanocrystals by limiting copper diffusion to growing nuclei.

  15. Fluorescence properties of Eu3+-doped alumino silicate glasses

    NASA Astrophysics Data System (ADS)

    Herrmann, Andreas; Kuhn, Stefan; Tiegel, Mirko; Rüssel, Christian

    2014-11-01

    Alumino silicate glasses of a very broad range of molar compositions doped with 1 ? 1020 Eu3+ cm-3 (about 0.2 mol% Eu2O3) were prepared. As network modifier oxides Li2O, Na2O, K2O, MgO, CaO, SrO, BaO, ZnO, PbO, Y2O3 and La2O3 have been used. All glasses show relatively broad fluorescence excitation and emission spectra. For most glasses only a weak effect of the glass composition on the excitation and emission spectra is observed. Although the glasses should be structurally similar, notable differences are found for the fluorescence lifetimes. These increase steadily with decreasing mean atomic weight, decreasing refractive index and decreasing optical basicity of the glasses, which may be explained by local field effects. An exception from this rule are the strontium, barium and potassium containing glasses, which show significantly increased fluorescence lifetimes despite of their high refractive index, optical basicity and molecular weight. The non mono-exponential fluorescence decay curves as well as the fluorescence spectra indicate a massive change in the local surroundings of the doped rare earth ions for these glasses.

  16. Luminescence properties of Sm3+-doped fluorosilicate glasses

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  17. White light generation from Dy3+ doped tellurite glass

    NASA Astrophysics Data System (ADS)

    Damak, Kamel; Yousef, El Sayed; Rüssel, Christian; Maâlej, Ramzi

    2014-02-01

    This paper reports on the spectral results of Dy3+ (1.0 mol%) ions-doped TeO2-ZnO-PbO-PbF2-Na2O (TZPPN) glass. Raman spectrum measurements, differential thermal analysis (DTA) profiles of this rare-earth ion-doped glass were carried out. From the DTA thermogram, glass transition (Tg), crystallization (Tc) and melting (Tm) temperatures were evaluated. Direct and indirect optical band gaps were calculated based on the glasses UV absorption spectra. From the absorption spectra, Judd-Ofelt (J-O) intensity parameters, ?k, were calculated. Using J-O intensity parameters, several radiative properties such as spontaneous transition probabilities (AR), radiative branching ratios (?R) and radiative lifetimes (?R) were determined for the excitation level 4F9/2. From the emission spectra, a strong yellow emission at 574 nm (4F9/2?6H13/2) was observed and it also showed a combination of blue and red emission bands for this glass. The stimulated emission cross-section ?(?p) was also evaluated for the 4F9/2?6HJ (J=11/2, 13/2, and 15/2) transitions. This study indicates that 1 mol% Dy2O3-doped tellurite glass can be considered for white light generation with the excitation of blue light (454 nm).

  18. Crystallization behavior of rare-earth doped fluorochlorozirconate glasses.

    PubMed

    Paßlick, C; Ahrens, B; Henke, B; Johnson, J A; Schweizer, S

    2011-06-01

    A series of fluorochlorozirconate (FCZ) glasses, each doped with a different rare-earth, was prepared and examined to determine thermal stability and activation energy, Ea , of the dopant dependent BaCl2 crystallization. Non-isothermal differential scanning calorimetry (DSC) measurements were done to investigate the endothermic and exothermic reactions upon heat treatment of the glass samples. In comparison to the rare-earth free FCZ glass, significant changes in the Hruby constant, Hr , and Ea were found due to the addition of a rare-earth and also between the individual dopants. PMID:23493406

  19. Crystallization behavior of rare-earth doped fluorochlorozirconate glasses

    PubMed Central

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

    2012-01-01

    A series of fluorochlorozirconate (FCZ) glasses, each doped with a different rare-earth, was prepared and examined to determine thermal stability and activation energy, Ea, of the dopant dependent BaCl2 crystallization. Non-isothermal differential scanning calorimetry (DSC) measurements were done to investigate the endothermic and exothermic reactions upon heat treatment of the glass samples. In comparison to the rare-earth free FCZ glass, significant changes in the Hruby constant, Hr, and Ea were found due to the addition of a rare-earth and also between the individual dopants. PMID:23493406

  20. Effect of irradiation on differential thermal properties and crystallization behavior of some lithium borate glasses

    Microsoft Academic Search

    N. A El-Alaily; R. M Mohamed

    2001-01-01

    Differential thermal properties and the crystallization behavior of binary system Li2O–B2O3 glasses were investigated. The effects of the presence of oxides of aluminum, lead or one of the transition metals TiO2 or V2O5 or Fe2O3 in the parent glass were also studied. The effects of three different heat treatments on the crystalline structure of all the studied glasses were also

  1. Effect of irradiation on differential thermal properties and crystallization behavior of some lithium borate glasses

    Microsoft Academic Search

    N. A. El-Alaily; R. M. Mohamed

    2001-01-01

    Differential thermal properties and the crystallization behavior of binary system Li2O-B2O3 glasses were investigated. The effects of the presence of oxides of aluminum, lead or one of the transition metals TiO2 or V2O5 or Fe2O3 in the parent glass were also studied. The effects of three different heat treatments on the crystalline structure of all the studied glasses were also

  2. Development of bismuth doped lead-aluminum-zinc-germanate glass as a broadband optical gain medium

    Microsoft Academic Search

    M. Hughes; T. Suzuki; Y. Ohishi

    2009-01-01

    In this paper we present the development process of a glass based on bismuth and aluminum co-doped germanate (GAB) glass. Other workers have demonstrated broadband optical gain in GAB glass. We found the addition of PbO to this glass (GAPB glass) increased the quantum efficiency (QE). Excitation of GAPB glass at 808 nm produced emission peaking at 1230 nm with

  3. Photosensitivity of germanium-doped silica glass and fibers

    NASA Astrophysics Data System (ADS)

    Grubsky, Victor

    Germanium-doped silica glass changes its refractive index when it is exposed with UV light. This effect is caused by intrinsic defects of germanosilicate glass called germanium oxygen-deficient centers (GODC). The photosensitivity of glass allows fabrication of various refractive-index gratings in germanosilicate optical fibers. These gratings are basic elements used by the telecommunication industry. Nevertheless, the physical mechanisms causing the index change in glass are still unclear. In this thesis we discuss some aspects of the photosensitivity of germanium-doped glass and optical fibers. First, we present a historic overview of the previous work on defects in glass and their role for photosensitivity. The photoionization and densification theories of photosensitivity are reviewed. We then consider the transformations of defects in glass caused by UV radiation. We show that an index change can be produced by exciting either 240-nm or 330-nm absorption bands of GODC. We prove that the excitation of GODC to their triplet state is essential to produce a change in the glass structure. We also show that UV radiation forms a new defect with a luminescence band at 650 nm. We study the nature of the increase in glass photosensitivity caused by saturating glass with molecular hydrogen before exposing it to UV light. Hydrogen-loading the glass increases the saturated value of its index change by at least an order of magnitude and allows the use of high-coherence lasers at 275-305 nm for efficient and high-precision fiber grating fabrication. We also show that the stability of the refractive index change in hydrogen-loaded fibers is correlated with the water content of the glass. The difference between the spectral dependencies of photosensitivity in hydrogen-loaded and hydrogen-free glass suggests that different mechanisms are responsible for the index change in these two cases. We propose possible photoinduced reactions of hydrogen with germanium-doped glass. Finally, we analyze the properties and new applications of long-period fiber gratings. Using specially designed quadratic-dispersion gratings, we make high-sensitivity sensors with variable transmission but fixed resonant wavelength. We also present fixed-wavelength intensity modulators and bandpass filters based on long-period gratings.

  4. Optical Nonlinearities in Semiconductor Doped Glass Channel Waveguides

    Microsoft Academic Search

    William Charles Banyai

    1988-01-01

    The nonlinear optical properties of a semiconductor -doped glass (SDG) channel waveguide were measured on a picosecond time-scale; namely, fluence-dependent changes in the absorption and the refractive index as well as the relaxation time of the nonlinearity. Slower, thermally -induced changes in the refractive index were also observed. The saturation of the changes in the absorption and the refractive index

  5. Flame retardancy mechanisms of aluminium phosphinate in combination with melamine polyphosphate and zinc borate in glass-fibre reinforced polyamide 6,6

    Microsoft Academic Search

    Ulrike Braun; Bernhard Schartel; Mario A. Fichera; Christian Jäger

    2007-01-01

    The fire retardancy mechanisms of aluminium diethylphosphinate in combination with melamine polyphosphate and zinc borate was analysed in glass-fibre reinforced polyamide 6,6. The influence of phosphorus compounds on the polyamide decomposition pathways was characterized using thermal analysis (TG), evolved gas analysis (TG–FTIR), and FTIR–ATR analysis of the residue. The Lewis acid–base interactions between the flame retardants, the amide unit, and

  6. Exceptionally narrow homogeneous linewidth in erbium-doped glasses.

    PubMed

    Sun, Y; Cone, R L; Bigot, L; Jacquier, B

    2006-12-01

    We show that rare-earth (RE-) doped glasses can have homogeneous linewidths as narrow as 287 kHz at (4)He temperatures. This is far narrower than others reported in glasses in the same temperature range and is suitable for precise spectral hole burning and spatial-spectral holographic applications. It is known that cw spectral hole burning linewidth measurements of RE ions in glasses are hindered by the presence of spectral diffusion but, even in glasses, application of a magnetic field can freeze out RE spin-spin interactions responsible for spectral diffusion and isolate the remaining contribution of two-level systems (TLSs). The Er(3+):2G2S glasses have unusually low TLS contributions, making it possible to study the real homogeneous linewidth using photon echo measurements. The contribution from TLSs is only 170 T(1.3) kHz when subjected to a field of 5 T. PMID:17099747

  7. FTIR spectra of pseudo-binary sodium borate glasses containing TeO2

    NASA Astrophysics Data System (ADS)

    Mansour, E.

    2012-04-01

    The glass system xTeO2·(100 - x)[0.5Na2O·0.5B2O3] was prepared and measured for Fourier transform infrared spectroscopy. The results show that [BO3] and [BO4] were among the main structural units in the investigated glasses as well as [TeO3] and [TeO4] groups. Evidence was observed for the presence of boroxol rings in these glasses. By introducing TeO2 into the glass network, the concentration of Na2O which is connected with B2O3 network is changed and hence trigonal to tetrahedral boron ratio. When 50% of the total Na2O content was associated with TeO2 minimum number of [TeO3] units was observed in the glass network. With higher than 40 mol% TeO2, there is a constancy of the concentration of [TeO4] units. Bonds of the type B-O-Te are common at high concentrations of TeO2 (>40 mol%) which is associated with an increase in the polymerization of the glass network. Introducing TeO2 into Na2O·B2O3 glasses (1:1) may delay the expected disappearance of non-bridging oxygens (NBOs) in the whole glass network with the decrease in the content of sodium oxide.

  8. Spectroscopic properties of lead fluoroborate glasses doped with ytterbium

    NASA Astrophysics Data System (ADS)

    Kassab, Luciana; Tatumi, Sonia H.; Morais, Alessandro; Courrol, Lilia C.; Wetter, Niklaus U.; Salvador, V.

    2001-05-01

    A new lead fluoroborate glass (PbO-PbF2-B2O3) doped with ytterbium (Yb:PbFB) is presented. Samples with different concentrations of Yb3+ were produced and had their emission cross-sections, fluorescence lifetimes and minimum pump intensities determined. They have high refractive index of 2.2 and a density of 4.4 g/cm3. For a doping level of 1.153x1020 ions/cm3, the fluorescence lifetime, after excitation at 968 nm, is 0.81 ms, which is comparable to Yb:tellurite laser glass. Also, an emission band at 1022 nm is measured with emission cross-section of approximately 1.07x10-20 cm2 and fluorescence effective linewidth of 60 nm, which is comparable to Yb:phosphate laser glass.

  9. Spectroscopic properties of lead fluoroborate glasses doped with ytterbium.

    PubMed

    Kassab, L; Tatumi, S; Morais, A; Courrol, L; Wetter, N; Salvador, V

    2001-05-01

    A new lead fluoroborate glass (PbO-PbF2-B2O3) doped with ytterbium (Yb:PbFB) is presented. Samples with different concentrations of Yb3+ were produced and had their emission cross-sections, fluorescence lifetimes and minimum pump intensities determined. They have high refractive index of 2.2 and a density of 4.4 g/cm3. For a doping level of 1.153x1020 ions/cm3, the fluorescence lifetime, after excitation at 968 nm, is 0.81 ms, which is comparable to Yb:tellurite laser glass. Also, an emission band at 1022 nm is measured with emission cross-section of approximately 1.07x10-20 cm2 and fluorescence effective linewidth of 60 nm, which is comparable to Yb:phosphate laser glass. PMID:19417856

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

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

    PubMed

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar

    2009-07-15

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

  12. Faraday Rotation in Rare-Earth Doped Glasses and Nanocrystalline II-VI Semiconductor Composites

    Microsoft Academic Search

    Joseph H. Kratzer; John Schroeder; Kristin A. Vogel; David B. Hall

    2001-01-01

    We have measured Faraday rotation in glasses doped with rare earth oxides. The base glass before doping consisted of 25Na2O.75SiO2. Faraday rotation studies were also done on Selected II-VI semiconductor nanocrystals contained in a glass composite. The quantum dots in these samples had average diameters from about 2 nm to 7 nm. The glass doped with Terbium oxide showed the

  13. EPR study of coordination of Ag and Pb cations in BaB 2 O 4 crystals and barium borate glasses

    Microsoft Academic Search

    V. P. Solntsev; R. I. Mashkovtsev; A. V. Davydov; E. G. Tsvetkov

    2008-01-01

    It is shown the possibility to determine the coordination of paramagnetic ions in disordered solid structures, e.g., in barium\\u000a borate glasses. For this purpose the electron paramagnetic resonance (EPR) method was used to study ?-and ?-BaB2O4 crystals and glasses of 45·BaO × 55·B2O3 and 40·BaO × 60·B2O3 (mol%) composition activated by Ag+ and Pb2+ ions. After the samples were exposed to X-rays at 77 K,

  14. Origin and enhancement of the second-order non-linear optical susceptibility induced in bismuth borate glasses by thermal poling

    Microsoft Academic Search

    O. Deparis; F. P. Mezzapesa; C. Corbari; P. G. Kazansky; K. Sakaguchi

    2005-01-01

    The second-order non-linear optical susceptibility of thermally poled glasses, ?(2), should be enhanced in proportion to the intrinsic third-order susceptibility ?(3), for a given frozen-in electric field (i.e. ?(2)=3Edc?(3)). In order to test this prediction, bismuth-borate (Bi2O3–ZnO–B2O3) glasses, for which ?(3) increased with increasing Bi2O3 content, were thermally poled and the second-order non-linear coefficient was determined. Poling conditions and current

  15. 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.

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

    SciTech Connect

    Khasa, S., E-mail: skhasa@rediff.com; Dahiya, M. S., E-mail: skhasa@rediff.com [Physics Department, Deenbandhu Chhotu Ram University of Science and Technology, Murthal-131039 (India); Agarwal, A. [Physics Department, Guru Jambheshwara University of Science and Technology, Hisar-125001 (India)

    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.

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

    SciTech Connect

    Yao, Aihua, E-mail: aihyao@126.com [Institute of Bioengineering and Information Technology Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China)] [Institute of Bioengineering and Information Technology Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China); Ai, Fanrong; Liu, Xin; Wang, Deping; Huang, Wenhai; Xu, Wei [Institute of Bioengineering and Information Technology Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China)] [Institute of Bioengineering and Information Technology Materials, School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China)

    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.

  18. EXAFS study of a "mixed-alkali" type effect in sodium-calcium borate glass

    NASA Astrophysics Data System (ADS)

    Brook, H. C.; Chadwick, A. V.; Mosslemans, J. F. W.; Greaves, G. N.

    Replacement of one alkali in a glass by another is known to have a profound effect on many physical properties in that glass. In the case of electrical conductivity, there is a nonlinear variation between the values of the two relevant single-alkali glasses, with a minimum at some mixed composition. This is referred to as the mixed-alkali effect (MAE), and has often been investigated using EXAFS, which shows a distinct change in the first-shell Debye-Waller factor at a composition usually corresponding to the minimum conductivity. However, investigations of the MAE have normally been restricted to alkali metal oxides, R2O, and other monovalent cation oxides. The authors have undertaken an EXAFS study of a series of glasses of general formula xNa2O·(1-x)CaO· 2B2O3 in order to ascertain whether a "mixed-alkali" type effect occurs between cations of differing charge, and whether any significant change in Debye-Waller factor occurs at the same percentage replacement as in glasses containing cations of similar charge.

  19. The effect of CuO and MgO impurities on the optical properties of lithium potassium borate glass

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    Previous study proved the efficiency of copper as one of the most luminescent activators. In this work, Li2CO3-K2CO3-H3BO3 (LKB) glasses co-doped with copper oxide (CuO) and magnesium oxide (MgO) have been prepared by chemical quenching technique. Two techniques have been applied to investigate the effect of co-dopants on the physical and optical properties of the new glass network. The X-ray Diffraction (XRD) results showed the amorphous nature of the sample. Fourier transform infrared (FTIR) spectra, 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 co-doped ions in the glass matrix. The exchange in the concentration of magnesium and copper ions illustrated the great effect of magnesium as a co-dopant on the Photoluminescence (PL) emission of LKB doped with copper oxide. Due to the change in the copper concentration, a broad green emission with intensity of around 300 (a.u) has been observed. Enhancement of about three times has been shown with the increment of 0.1 mol% of CuO and MgO as a co-dopant technique. It is well known that magnesium oxide alone does not show strong-luminescence, but during this increment, MgO acted as activator (co-dopant) for Cu ions. This enhancement may contribute to the energy transfer from Mg2+ ions to monovalent Cu+ ion. The current results are discussed and compared with other related studies.

  20. Silver doped nanobioactive glass particles for bone implant applications

    SciTech Connect

    Prabhu, M.; Kavitha, K.; Karunakaran, G.; Manivasakan, P.; Rajendran, V. [Centre for Nanoscience and Technology, K. S. Rangasamy College of Technology, Tiruchengode - 637215, Namakkal (DT), Tamil Nadu (India)

    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.

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

    Microsoft Academic Search

    G. Senthil Murugan; K. B. R. Varma

    1999-01-01

    Glasses in the system (1 ? x)Li2B4O7–xBi2WO6 (0.1 ? x ? 0.35) were prepared by splat 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 (HRTEM) revealed the presence of fine, nearly spherical crystallites of Bi2WO6 varying from 1.5 to 20 nm in size, depending on x

  2. Structure of zinc-borate low-melting glasses derived from IR spectroscopy data

    Microsoft Academic Search

    N. M. Bobkova; S. A. Khot’ko

    2005-01-01

    The IR spectra of glasses of the ZnO—SrO—B2O3 system with constant additions of PbO, Al2O3, and Li2O (20 mol. % in sum) were studied. It is established that on replacement of B2O3 by ZnO, the structure of the glasses is characterized by the presence of groupings with the bridge bonds BIII— O—BIII, BIII—O—BIV, BIV—O—BIV and end groups BIII— O?; ZnO

  3. Laser Spectroscopic Studies of Europium-Doped Glasses and Emerald

    Microsoft Academic Search

    Gregory James Quarles

    1987-01-01

    Scope of study. High-power, picosecond-pulse excitation was used in the first part of this work to study the dynamics of the pumping and decay processes in Eu ^{3+}-doped fluoride and oxide glasses. Time resolved spectroscopy techniques are used to determine the absorption cross sections of the intermediate state and a Judd-Ofelt analysis of the absorption spectrum is used to determine

  4. Optical Nonlinearities and Ultrafast Carrier Dynamics in Semiconductor Doped Glasses

    Microsoft Academic Search

    V. S. Williams; G. R. Olbright; B. D. Fluegel; S. W. Koch; N. Peyghambarian

    1988-01-01

    The linear and nonlinear optical properties of commercially available CdSxSe1m x doped glasses are reviewed and the origin, magnitude, and temporal response of the nonlinearities are discussed. The room-temperature carrier dynamics are analysed using femtosecond interband pump-probe measurements. Our experimental results show the evolution of the carriers into a hot, quasi-thermal plasma distribution via electron-electron and electron-phonon scattering. The quasi-thermal

  5. Characterization of Er3 + -doped glasses by fluorescence line narrowing

    Microsoft Academic Search

    S. Zemon; G. Lambert; L. J. Andrews; W. J. Miniscalco; B. T. Hall; T. Wei; R. C. Folweiler

    1991-01-01

    The Stark levels of the 4I15\\/2 ground state manifold have been determined for Er3+-doped fluorozirconate, fluorophosphate, phosphate, and silicate bulk glasses from fluorescence-line-narrowing (FLN) measurements at 4.2 K. Splittings between adjacent Stark levels were observed to be 10–140 cm?1 and the total energy spread of the manifold was found to range from 335 to 400 cm?1. The position of a

  6. 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 [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Rivera-Lopez, F.; Rodriguez-Mendoza, U. R.; Lavin, V. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200 San Cristobal de La Laguna, Santa Cruz de Tenerife (Spain); Vijaya, R.; Jayasankar, C. K.; Rama Moorthy, L. [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India)

    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.

  7. Study of kinetics of the phase separation in sodium borate glasses

    Microsoft Academic Search

    W.-F. Du; K. Kuraoka; T. Y AZAWA; T. Yazawa

    2000-01-01

    The kinetics of the phase separation in 15Na2O-85B2O3 binary glasses was investigated using 11B nuclear-magnetic-resonance (NMR) spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM) observation. It was found that the equilibrium of the phase separation took long time due to the growth of a boron-rich phase and the composition fluctuation in Na-rich phase. Although the XRD results showed that

  8. EPR and Magnetic Susceptibility Studies of Calcium-Borate Oxide Glasses Containing Iron Ions

    Microsoft Academic Search

    I. Ardelean; P. Pascuta; M. Peteanu

    2002-01-01

    EPR and magnetic susceptibility measurements have been performed on xFe2O3.(100-x) [3B2O3.CaO] glasses with 0

  9. EPR and Magnetic Susceptibility Studies of Calcium-Borate Oxide Glasses Containing Iron Ions

    NASA Astrophysics Data System (ADS)

    Ardelean, I.; Pascuta, P.; Peteanu, M.

    EPR and magnetic susceptibility measurements have been performed on xFe2O3.(100-x) [3B2O3.CaO] glasses with 0

  10. Irradiation effect on the acoustical properties of zinc lead borate glasses

    Microsoft Academic Search

    G. Sharma; K. Singh; Manupriya; H. S. Klare; V. Rajendran; A. V. Gayathri Devi; S. B. Narang

    2005-01-01

    The effect of -irradiation on the acoustical properties of xZnO.2xPbO.(1-3x)B2O3 glasses has been studied. Ultrasonic velocity and attenuation measurements have been made before and after -irradiation at room temperature in the frequency range 2.25-10 MHz. From the measured density and ultrasonic velocity data, the elastic moduli, Poisson's ratio and other parameters have been obtained. Changes in the acoustical properties are

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

    SciTech Connect

    Borodi, G. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Pascuta, P.; Dan, V.; Pop, V. [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania)] [Technical University, 28 Memorandumului, 400114 Cluj-Napoca (Romania); Stefan, R. [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania)] [Agricultural Science and Veterinary Medicine University, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania); Radulescu, D. [University of Medicine and Pharmacy Iuliu Hatieganu, 8 Victor Babes, 400012 Cluj-Napoca (Romania)] [University of Medicine and Pharmacy Iuliu Hatieganu, 8 Victor Babes, 400012 Cluj-Napoca (Romania)

    2013-11-13

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy measurements have been employed to investigate the (Gd2O3)x?(B2O3)(60-x)?(ZnO)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 ZnB4O7, Zn4O(B6O12), Zn3(BO3)2 and GdBO3. 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 BO3, BO4 and ZnO4 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.

  13. Thermal and optical properties of Tm3+ doped tellurite glasses.

    PubMed

    Ozen, G; Demirata, B; Oveço?lu, M L; Genç, A

    2001-02-01

    Ultraviolet, visible (UV/VIS) and differential thermal analysis (DTA) measurements were carried out in order to investigate the optical and thermal properties of various 0.5 mol.% Tm2O3 containing (1 - x)TeO2 + xLiCl glasses in molar ratio. The samples were prepared by fusing the mixture of their respective reagent grade powders in a platinum cricuble at 750 degrees C for 30 min. DTA curves taken in the 23-600 degrees C temperature range with a heating rate of 10 degrees C/min reveal a change in the value of the glass transition temperature, Tg, while melting was not observed for the glasses containing LiCl content less than 50 mol.%. These glasses were found to be moisture-resistant. However, the glasses with LiCl content higher than 50 mol.%, in which a melting peak was observed at Tc = 401 degrees C, were moisture-sensitive. Absorption measurements in the UV/VIS region of the glasses without Tm2O3 content show that the Urbach cutoff occurs at about 320 nm and, is relatively independent of the LiCl content. Six absorption bands were observed in the Tm2O3 doped glasses corresponding to the absorption of the 1G4, 3F2, 3F3 and 3F4, 3H5 and 3H4 levels from the 3H6 ground level of Tm3+ ions. The spectra also show that the integrated absorption cross-section of each band depends on the glass composition. Judd-Ofelt theory was used to determine the Judd-Ofelt parameters as well as the radiative transition probabilities for the metastable levels of Tm3+ ions in (0.3)LiCl + (0.7) TeO2: 0.01 Tm2O3 glass which is moisture-resistant. PMID:11206561

  14. Glasses of heavy metal and gallium oxides doped with neodymium

    NASA Astrophysics Data System (ADS)

    Kassab, L. R. P.; Courrol, L. C.; Wetter, N. U.; Tatumi, S. H.; Mendes, C. M. S. P.

    Optical and physical properties of a new family of Nd: BPG (Bi2O3-PbO-Ga2O3) glasses are presented at 1 mol% Nd doping level. Knoop hardness of 321 kg/mm2 and density of 4.63 g/cm3 were measured. These high refractive index glasses present a very large absorption cross section of 2.5 × 10-20 cm2 at 800 nm. Emission occurs at three bands centered at 877 nm, 1066 nm and 1341 nm with a fluorescence lifetime associated to these transitions of 110 ?s. At 1066 nm, the spectral linewidth is 30 nm. These properties make these glasses good candidates for laser action.

  15. Rapid thermal annealing of thin doped and undoped spin-on glass films

    Microsoft Academic Search

    L. Ventura; A. Slaoui; J. c. Muller; P. Siffert

    1995-01-01

    Rapid thermal annealing (RTA) was investigated for curing doped and undoped spin-on glass films deposited onto silicon substrates. The annealed undoped spin-on glass (SOG) films present an important densification of the layers as a function of temperature and a reduction in the interfacial state density. The possibility of using rapid thermally annealed spin-on doped glass (SOD) films as a doping

  16. Growth and spectroscopic properties of ytterbium-doped lanthanum calcium borate (Yb 3+:La 2CaB 10O 19) crystal

    Microsoft Academic Search

    Rui Guo; Yicheng Wu; Peizhen Fu; Fangli Jing

    2005-01-01

    A new ytterbium-doped lanthanum calcium borate crystal (Yb3+:La2CaB10O19, Yb:LCB) has been grown by the flux method. The spectroscopic properties have been investigated and the fundamental spectral parameters for Yb:LCB crystal have been calculated. Yb:LCB crystal has the strongest absorption at 976 nm with a full-width at half-maximum of 14 nm. The absorption and emission cross-sections are 1.16×10?20 and 3.51×10?20 cm2,

  17. 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.

  18. Overview of Nd and Er-Doped glass integrated optics amplifiers and lasers

    Microsoft Academic Search

    S. Iraj Najafi

    1997-01-01

    There has been significant progress since 1990 on development of rare-earth-doped glass integrated optics amplifiers and lasers. Several fabrication processes were utilized to make rare-earth-doped waveguides. Neodymium and erbium doped waveguides were successfully produced, and amplifiers and lasers were demonstrated. Recently, high performance erbium-doped amplifiers in phosphate glasses were achieved. In this paper, we review the progress in development of

  19. 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.

  20. 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.

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

    SciTech Connect

    Deshpande, A. V. [Department of Applied Physics, Visvesvaraya National Institute of Technology, Nagpur-440010 (India); Raut, V. D., E-mail: vijaya.raut@raisoni.net [Department of Applied Physics, G.H. Raisoni College of Engineering, Nagpur-440016 (India)

    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.

  2. Lead-salt quantum dot doped glasses for photonics

    NASA Astrophysics Data System (ADS)

    Auxier, Jason Michael

    In this dissertation, I present photonics applications of PbS quantum-dot-doped (QD-doped) glasses. The dissertation consists of two major parts: bulk material applications (Cr:forsterite laser modelocking, bleaching dynamics, optical gain, and photo-luminescence) and the fabrication of QD-doped ion-exchanged waveguides. When this work began, these PbS QD-doped glasses were the state-of-the-art in quantum dot glasses due to their narrow size distribution. Modelocking of a Cr:forsterite laser using this glass as a saturable absorber had been demonstrated, with little understanding of the dynamics. This work began by studying the dynamics of the saturable absorber to explain the ps-pulse width. In the bulk measurements, I functioned as a secondary researcher. In the laser modelocking and bleaching measurements, my contribution was laser cavity alignment, sample preparation, collecting autocorrelation traces, and aiding in the setup and data collection for the bleaching measurements. On this work, I coauthored one refereed journal article in Applied Physics Letters [1] and one refereed conference paper [2], for which I am third and second author, respectively. For the gain measurements, I aided in the setup and data collection, whereas I setup and took most of the luminescence data. The gain measurements resulted in one second-author refereed journal article in Applied Physics Letters [3] and I presented the luminescence results at CLEO2000 [4]. I took the lead role in the waveguide fabrication and characterization and authored refereed journal articles in Applied Physics Letters [5], Journal of Applied Physics [6], and Journal of the Optical Society of America B [7]. I also presented an invited talk at Photonics West [8] and presented at CLEO200-1 [9]. Additionally, I have been a coauthor of presentations at the Nanotechnology Symposium (2006), American Ceramic Society [10], and Photonics Europe ( 2006) [11]. A book chapter in The Photonics Handbook, 2nd edition [12] also discusses this work. The next step is to focus on reducing the waveguide losses. This requires new, circular wafers with better surface quality and glass homogeneity. I suggest using silver-film ion exchange followed by a field-assisted burial to eliminate the surface interaction.

  3. Americium concentrations in solutions contacting americium-doped glass

    SciTech Connect

    Rai, D.; Schramke, J.A.; Moore, D.A.; Mc Vay, G.L.

    1986-12-01

    Americium-doped glass (0.053 wt% /sup 241/Am) was contacted with dilute salt solutions (0.001 M NaCIO/sub 4/), pH buffers, Permian Basin brine (PBB1), and ten-times-diluted PBB1 to determine the aqueous americium concentrations that can be expected in equilibrium with this glass. The americium concentrations in all of these solutions were similar and decreased with increasing pH; americium concentrations decreased to the detection limit (--10/sup -11.6/ M) at a pH value of --7 and remained at or near the detection limit at pH values > 7. Americium concentrations in glass suspensions with pH >5 were found to be controlled by the dissolution of an americium-solid. The value of the log of the equilibrium constant for the solubility of this americium-solid (Am-solid + 3H/sup +/ = Am/sup 3+/ + H/sub 3/-solid) was determined to be -- 10.3. The americium-solid is found to effectively control aqueous americium to very low concentrations under slightly acidic to alkaline conditions. The high ionic strength and the high CI/sup -/ concentrations in brine are found not to measurably affect the americium-solid solubility. The objectives of the present study were (a) to develop a data base that can be used to predict aqueous americium concentrations in equilibrium with americium-doped glass and (b) to determine the influence of high ionic strength and high chloride concentrations, conditions that are expected in salt repositories, on the leachability or solubility of an americium-containing glass.

  4. Transmittance properties and TEM observation of metal doped glass by field-assisted ion exchange

    NASA Astrophysics Data System (ADS)

    Matsusaka, Souta; Nomura, Taketsugu; Hidai, Hirofumi; Chiba, Akira; Morita, Noboru

    2014-08-01

    Metal (silver or copper) ions were doped into borosilicate glass using an electric field- assisted ion exchange method. The optical transmittance of the metal doped glass was measured to determine why the doped glass exhibited an excellent laser micro-machinability. The doped metal ions were found to have enhanced the optical absorption of the glass, especially in the ultraviolet range. This in turn facilitated the efficient absorption of incident laser irradiation, and hence improved laser machinability of the glass. The metal doped glass also exhibited some absorption in the visible range, leading to a slight yellow-brown coloration. Transmission electron microscope (TEM) observations indicated that the metal ions had penetrated the glass and therein formed nanometer-sized (~6 nm) fine particles. In an attempt to control the optical characteristics in the ultraviolet-visible range, metal doped glass was heat-treated following the ion exchange doping step. In the case of silver-doped glass with heat treatment at 723 K, silver nanoparticles aggregated locally yielding an inhomogeneous structure. The heat-treated samples had a high optical absorption in the ultraviolet range.

  5. Growth and spectroscopic properties of ytterbium-doped lanthanum calcium borate (Yb 3+:La 2CaB 10O 19) crystal

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Wu, Yicheng; Fu, Peizhen; Jing, Fangli

    2005-01-01

    A new ytterbium-doped lanthanum calcium borate crystal (Yb 3+:La 2CaB 10O 19, Yb:LCB) has been grown by the flux method. The spectroscopic properties have been investigated and the fundamental spectral parameters for Yb:LCB crystal have been calculated. Yb:LCB crystal has the strongest absorption at 976 nm with a full-width at half-maximum of 14 nm. The absorption and emission cross-sections are 1.16 × 10 -20 and 3.51 × 10 -20 cm 2, respectively. The fluorescence lifetime is 0.95 ms. The ground-state energy level splitting is calculated to be 640 cm -1. In comparison with other Yb-doped laser crystals, the calculated parameters show that Yb:LCB crystal satisfies the fundamental spectral condition for laser emission.

  6. Er-doped and Er, Yb co-doped oxyfluoride glasses and glass-ceramics, structural and optical properties

    NASA Astrophysics Data System (ADS)

    Lisiecki, Rados?aw; Augustyn, El?bieta; Ryba-Romanowski, Witold; ?elechower, Micha?

    2011-09-01

    The selected glasses and glass-ceramics pertinent to following chemical composition in mol%:48%SiO 2-11%Al 2O 3-7%Na 2O-10%CaO-10%PbO-11%PbF 2-3%ErF 3 and 48%SiO 2-11%Al 2O 3-7%Na 2O-10%CaO-10%PbO-10%PbF 2-1%ErF 3-3%YbF 3 have been manufactured from high purity components (Aldrich) at 1450 °C in normal atmosphere. Glass optical fibers were successfully drawn. Subsequently they were subject to the heat-treatment at 700 °C in various time periods. The preceding differential thermal analysis (DTA) studies allowed estimating both the fiber drawing temperature and the controlled crystallization temperature of glass fibers. It has been observed that the controlled heat-treatment of oxyfluoride glass fibers results in the creation of Pb 5Al 3F 19, Er 4F 2O 11Si 3 and Er 3FO 10Si 3 crystalline phases. The identified phases were characterized by X-ray powder diffraction (XRD) and confirmed by selected area electron diffraction (SAED). The fibers consist of mixed amorphous-crystalline microstructure with nano-crystals of size even below 10 nm distributed in the glassy host. Their morphology was investigated applying high-resolution transmission electron microscopy. Optical properties and excited state relaxation dynamics of optically active ions (Er 3+, Yb 3+) in glass and glass-ceramics have been studied. Based on absorption spectra the Judd-Ofelt analysis was carried out. The main attention was directed to NIR luminescence at. 1.6 ?m related to 4I 13/2 ? 4I 15/2 Er 3+ and less effective emission associated with 4I 11/2 ? 4I 15/2 Er 3+ and 2F 5/2 ? 2F 7/2 Yb 3+ transitions. The dissimilar spectroscopic properties have been revealed for glasses and glass-ceramic samples, respectively. The reduction of emission linewidth at 1.6 and 1.0 ?m combined with substantial increase of 4I 13/2 lifetimes of erbium in glass-ceramics appear to be evidences that Er 3+ ions are accommodated in crystalline phases. The structural and optical characteristics of oxyfluoride glass-ceramic fibers indicate that these optical systems may be considered as promising materials for Er-doped optical amplifiers operating within third telecommunication window.

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

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

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

  8. Synthesized rare-earth doped oxide glasses for nonlinear optics

    NASA Astrophysics Data System (ADS)

    Kityk, I. V.; Wasylak, J.; Benet, S.; Dorosz, D.; Kucharski, J.; Krasowski, J.; Sahraoui, B.

    2002-09-01

    Photostimulated nonlinear optical effects in synthesized PbO-Ga2O3-Bi2O3-CdO (PGBC) glasses doped by Yb3+, Er3+, and Dy3+ rare-earth (RE3+) ions were discovered. Temperature-dependent measurements of optical photoinduced second-harmonic generation (PISHG) and two-photon absorption were performed in the infrared (IR) range. CO pulse laser (lambda=5.5 mum, energy power density up to 3.8 GW/cm2 per pulse) was applied as a source of IR-photoinducing and probing (fundamental) light. Absolute values of the PISHG were more than 22% higher than corresponding values obtained for other glasses: As2Te3-CaCl2-PbCl2 1 or Sb2Se3-BaCl2-PbCl2 2 type. The investigated PGBC system possesses a shorter time response (about 18 ps), compared with other IR nonlinear optical glasses. We have also established that all nonlinear optical susceptibilities are dependent on the type of RE3+ ion. A maximal value of the PISHG is achieved for the glasses doped by Yb3+. The PISHG values increase significantly below 25 K. We have carried out ab initio molecular dynamics and quantum chemical simulations in order to evaluate the possible contribution of electron-phonon anharmonic interactions in the observed phenomena. We have modeled the influence of the external CO photoinduced beam through the photoinduced anharmonic electron-phonon interactions. A decrease of the delaying time response is achieved. To obtain independent confirmation of the observed dependencies, we have carried out measurements of the epsilon2)(E during the external IR pumping. We have also compared the measured and theoretically calculated dependencies of the IR-induced effects.

  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. Spectroscopic studies on Fe 3+ and Mn 2+ doped SrB 4O 7 glasses

    NASA Astrophysics Data System (ADS)

    Prakash, I. N.; Babu, B.; Venkata Reddy, Ch.; Narayana Murty, P.; Reddy, Y. P.; Sambasiva Rao, P.; Ravikumar, R. V. S. S. N.

    2011-09-01

    EPR and optical absorption studies on Fe 3+ and Mn 2+ doped strontium tetraborate (SrB 4O 7) glasses are carried out at room temperature. The EPR spectrum of the Fe 3+ doped glass consists of signals with g-values 9.04, 4.22 and 2.04, whereas the EPR spectrum of Mn 2+ doped glass exhibits a characteristic hyperfine sextet around g=2.0. The spectroscopic analyses of the obtained results confirmed distorted octahedral site symmetry for the Fe 3+ and Mn 2+ impurity ions. Crystal field and Racah parameters evaluated from optical absorption spectra are: Dq=790, B=700 and C=3000 cm -1 for Fe 3+doped glass and Dq=880, B=700 and C=2975 cm -1 for Mn 2+ doped glass.

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

    E-print Network

    Paris-Sud XI, Université de

    Fabrication of Rare Earth-Doped Transparent Glass Ceramic Optical Fibers by Modified Chemical Vapor * Corresponding author: wilfried.blanc@unice.fr Rare earth (RE) doped silica-based optical fibers with transparent and amplifiers. 1 #12;I. Introduction Developing of new rare-earth (RE)-doped optical fibers for power amplifiers

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

    PubMed

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

    2011-11-01

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

  13. 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. [CEA, LETI, Département Optronique, F-38054 Grenoble (France); Kolobov, A. V.; Fons, P. [Nanodelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 4, Higashi 1-1-1, Tsukuba, Ibaraki 305-8562 (Japan); SPring-8, Japan Synchrotron Radiation Institute (JASRI), Kouto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Mitrofanov, K. V.; Tominaga, J. [Nanodelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 4, Higashi 1-1-1, Tsukuba, Ibaraki 305-8562 (Japan); Tamenori, Y. [SPring-8, Japan Synchrotron Radiation Institute (JASRI), Kouto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    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.

  14. 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.

  15. Laser Spectroscopic Studies of Europium-Doped Glasses and Emerald.

    NASA Astrophysics Data System (ADS)

    Quarles, Gregory James

    1987-05-01

    Scope of study. High-power, picosecond-pulse excitation was used in the first part of this work to study the dynamics of the pumping and decay processes in Eu ^{3+}-doped fluoride and oxide glasses. Time resolved spectroscopy techniques are used to determine the absorption cross sections of the intermediate state and a Judd-Ofelt analysis of the absorption spectrum is used to determine the branching ratios, radiative and nonradiative decay rates. Nondegenerate four-wave mixing and time-resolved site-selection spectroscopy were used to study energy migration processes in Be_3Al_2 (SiO_3)_6:Cr ^{3+}. Site-selection spectroscopy probed the short range spectral energy transfer among nonresonant Cr^{3+} ions in emerald. Four -wave mixing techniques were used to study the long range spatial diffusion of energy among resonant Cr^ {3+} ions. Findings and conclusions. From the study of the europium-doped glasses, it was possible to determine fluorescence lifetimes, branching ratios, radiative and nonradiative decay rates, and the two-phonon absorption cross sections for the fluoride glass. The oxide glass showed no transitions associated with two-photon absorption. From studies of the variations in the emission intensities of Eu ^{3+} in the fluoride glass versus laser power, it was possible to conclude that the excitation processes are either virtual two-photon excitation processes or are coherent sequential two-photon excitation processes in which fast phonon dephasing processes play a key role. From the studies of energy migration in emerald, it was found that there are two distinct types of energy transfer processes taking place. Using site-selection spectroscopy, short range spectral energy transfer was observed between Cr^{3+} ions in slightly different crystal field sites in emerald. It was found that the appropriate model for spectral energy transfer in emerald is one in which the excitation undergoes multistep migration among sensitizers before transfer takes place to the activator. Spatial energy migration was observed among resonant Cr^{3+} sites in emerald using nondegenerate four-wave mixing spectroscopy. The appropriate model for this transfer indicates that a long range, partially coherent exciton migration takes place. Estimations of the nonradiative decay rate from the ^4 T_2 to ^2 E states were made through calculations of the dephasing time of the excited state from the four-wave mixing scattering efficiency data.

  16. Dispersion and thermal properties of lithium aluminum silicate glasses doped with Cr3+ ions

    Microsoft Academic Search

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

    2006-01-01

    A series of new lithium aluminum silicate (LAS) glass systems doped with chromium ion is prepared. The reflectance and transmittance of the glass slabs are recorded. By means of an iteration procedure, the glass refractive index n and the extinction coefficient k and their dispersions are obtained. Across a wide spectral range of 0.2-1.6 mum, the dispersion curves are used

  17. Broad-Spectrum Bactericidal Activity of Ag2O-Doped Bioactive Glass

    Microsoft Academic Search

    Maria Bellantone; Huw D. Williams; Larry L. Hench

    2002-01-01

    Bioactive glass has found extensive application as an orthopedic and dental graft material and most recently also as a tissue engineering scaffold. Here we report an initial investigation of the in vitro antibacterial properties of AgBG, a novel bioactive glass composition doped with Ag2O. The bacteriostatic and bactericidal properties of this new material and of two other bioactive glass compositions,

  18. Thermo-optical characteristics and concentration quenching effects in Nd3+doped yttrium calcium borate glasses

    Microsoft Academic Search

    D. R. S. Santos; C. N. Santos; A. S. S. de Camargo; W. F. Silva; W. Q. Santos; M. V. D. Vermelho; N. G. C. Astrath; L. C. Malacarne; M. S. Li; A. C. Hernandes; A. Ibanez; C. Jacinto

    2011-01-01

    In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd2O3-(5?x)Y2O3–40CaO-55B2O3 (0 ? x ? 1.0 mol%). Their fluorescence quantum efficiency (&eegr;) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Fo¨rster–Dexter

  19. Thermo-optical characteristics and concentration quenching effects in Nd3+doped yttrium calcium borate glasses

    Microsoft Academic Search

    D. R. S. Santos; C. N. Santos; A. S. S. de Camargo; W. F. Silva; W. Q. Santos; M. V. D. Vermelho; N. G. C. Astrath; L. C. Malacarne; M. S. Li; A. C. Hernandes; A. Ibanez; C. Jacinto

    2011-01-01

    In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd2O3-(5-x)Y2O3-40CaO-55B2O3 (0 <= x <= 1.0 mol%). Their fluorescence quantum efficiency (?) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Förster-Dexter

  20. 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.

  1. Structural studies of rare-earth doped phosphate glasses

    SciTech Connect

    Matic, A.; Boerjesson, L. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Applied Physics; Wannberg, A.; McGreevy, R.L. [Studsvik Neutron Research Lab., Nykoeping (Sweden)

    1997-12-31

    The authors have performed neutron scattering experiments on rare-earth (La, Pr, Ho) doped phosphate glasses around the metaphosphate composition R(PO{sub 3}){sub 3}. Combining the diffraction experiment with Reverse Monte Carlo simulations they obtain a 3-D model of the structure. The models propose a rare-earth ion environment primarily consisting of oxygens with the average rare earth-oxygen distances; 2.56, 2.51 and 2.40 for the La, Pr and Ho samples respectively. They also observe that the rare earth ions are not uniformly distributed. The first R-R shell is on average about 3.3 {angstrom} to be compared with a value of 7 {angstrom} for a uniform distribution of R ions in the structure. From the models the authors also conclude that a chain like structure of the phosphate network is in agreement with the experiment.

  2. Optical characterization of Er-doped glasses for solar-pumped laser applications

    NASA Astrophysics Data System (ADS)

    Suzuki, Takenobu; Iwata, Yasuyuki; Nogata, Kohei; Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Ohishi, Yasutake

    2013-03-01

    Quantum efficiencies of Er3+-doped silicate, phosphate, tellurite and fluoride glasses have been examined under simulated sunlight excitation. The quantum efficiency of the whole emission bands was obtained as about 75 % for fluoride glass and about 2 % for silicate glass. The maximum quantum efficiency of the emission band at 1530 nm was about 35 % for fluoride glass and about 17 % for silicate glass. The product of the stimulated emission cross-section and the emission lifetime ?st?f was about 46×10-24 cm2 sec for fluoride glass and about 54×10-24 cm for silicate glass. These values are about 2-4 times larger than that of Nd-doped glasses.

  3. Optical fibre made from heavy metal oxide glasses doped by Dy3+ ions

    NASA Astrophysics Data System (ADS)

    Dorosz, Dominik

    2005-09-01

    Optical fibres made from heavy metal oxide glasses doped by Dy3+ ions with the numerical aperture 0,4 - 0,9 are presented. Heavy metal oxide glasses in the system PbO-Ga2O3-Bi2O3-CdO doped by 1500 ppm Dy3+ ions were used. The method of their preparation and physical properties as well the results of luminescence investigations of Dy3+ ions embedded in glass hosts are reported. Double-crucible drawing technique was applied to obtain optical fibre doped by Dy3+ ions. Core and cladding glasses have been obtained by modification the base glass with small amounts of cadmium and gallium. In such a way these glasses possessed the same technological parameters which can be controlled in a wide range.

  4. Rare-earth-doped waveguide lasers in glass and LiNbO3: a review

    Microsoft Academic Search

    Kim A. Winick

    1998-01-01

    This paper presents an overview of rare earth-doped waveguide lasers in both glass and lithium niobate (LiNbO3). The historical development of these devices together with the most recent advances in the field are described.

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

    PubMed

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

    2015-09-01

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

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

    E-print Network

    Sheik-Bahae, Mansoor

    Advances in laser cooling of thulium-doped glass C. W. Hoyt, M. P. Hasselbeck, and M. Sheik December 9, 2002 Recent developments in cooling thulium-doped heavy-metal fluoride glass are presented. Thulium-doped fluo- rozirconate (ZBLANP) is cooled to 19 K below ambient with a multiple-pass pump scheme

  7. Electronic polarizability and optical parameters of Er3+\\/Yb3+ co-doped phosphate glasses

    Microsoft Academic Search

    Feng Song; Chengguo Ming; Wentao Wang; Lanjun Luo

    2010-01-01

    The samples of Er3+\\/Yb3+ co-doped phosphate glasses with different Er3+ doped concentrations were prepared by high-temperature melting method. By calculating the electronic polarizabilities and optical basicity of the samples, we find, with the increasing of Er3+ ions concentration, the polarizability and optical basicity of oxide ions become large, which indicates that the covalence of the glasses becomes small. Based on

  8. FLUORESCENCE PROPERTIES OF As2S3 GLASS DOPED WITH RARE-EARTH ELEMENTS

    Microsoft Academic Search

    M. Iovu; A. Andriesh; I. Culeac

    Chalcogenide glasses doped with various rare-earth ions are extensively studied as potential materials for fiber optic amplifiers operating at 1.3 and 1.5 ?m telecommunication windows. The experimental results on optical absorption and photoluminescence of arsenic sulfide glasses and optical fibers doped with rare-earth elements (Pr3+, Sm3+, Er3+ and Dy3+) are presented. Near the absorption edge the rare-earth impurities affect strongly

  9. The Verdet constant of Er-doped crystalline YAG and tellurite glass at 1645 nm

    NASA Astrophysics Data System (ADS)

    Harris, Lachlan; Ottaway, David; Veitch, Peter J.

    2012-02-01

    We describe the measurement of the Verdet constant of undoped and Er-doped crystalline YAG and tellurite glass at 1645 nm. The undoped YAG value is compared to those measured using visible light. We show that the paramagnetic nature of Er reduces the Verdet constant but that the decrease is probably not significant for the typical Er doping levels used in Er:YAG or in Er:tellurite-glass mid-IR lasers.

  10. Luminescence efficiency growth in wide band gap semiconducting Bi2O3 doped Cd0.4Pb0.1B0.5 glasses and effect of ?-irradiation

    NASA Astrophysics Data System (ADS)

    Marzouk, M. A.; Ibrahim, S.; Hamdy, Y. M.

    2014-11-01

    Cadmium lead borate glasses together with other glasses containing different Bi2O3-doping concentrations (2.5, 5, 7.5, 10 mol%) were prepared by conventional melt annealing method. The density and molar volume values were calculated to obtain some insight on the packing density and arrangement in the network. Also their optical and structural properties have been characterized by means of X-ray diffraction, UV-visible spectroscopy, luminescence spectroscopy and FTIR spectroscopy. Optical measurements have been used to determine the optical band gap (Eg), Urbach energy (?E) and the refractive index (n). The results demonstrate the effective rule of Bi2O3 on the studied glasses. The undoped and Bi2O3 doped - glass show strong extended UV-near visible absorption bands which are attributed to the collective presence of both trace iron impurities from raw materials and also the sharing of bismuth Bi+3 ions. Furthermore, the luminescence intensity strongly increases with increasing Bi2O3 content which may be attributed to transfer of energy from transitions in its energy levels. It has been revealed that the decreasing values of optical band gap and band tail can be understood and related in terms of the structural changes that are taking place in the glass samples. The infrared absorption spectra of the prepared glasses show characteristic absorption bands related to the borate network (BO3, BO4 groups) together with vibrational modes due to Bi-O groups upon the introduction of Bi2O3. The prepared samples reveal a very limited response towards of gamma irradiation which reflects its shielding behavior towards the effect of such type of irradiation.

  11. 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.

  12. Visible emission in Sm3+ and Tb3+ doped phosphate glass excited by UV radiation

    NASA Astrophysics Data System (ADS)

    Zmojda, Jacek; Dorosz, Dominik; Kochanowicz, Marcin; Miluski, Piotr; Czajkowski, Karol; Ragin, Tomasz

    2013-10-01

    In the article analysis of UV absorption and visible fluorescence of Sm3+ and Tb3+ ions doped phosphate glass with molar composition: 65P2O5 + 8Al2O3 + 10BaO + 17(Na2O + MgO + ZnO) have been investigated. As a result of optical pumping fabricated glass with radiation from a deuterium lamp four luminescence bands were observed near to the wavelength of 600 nm for Sm3+ ions and 550 nm for Tb3+ ions. It was found that larger energy gap between laser and ground levels leads to the strongest emission in the visible range in terbium doped glasses than in glasses doped with samarium ions. Both fabricated glasses are characterized by the ability to selectively detect the radiation in the UV range.

  13. The Verdet constant of Er-doped crystalline YAG and tellurite glass at 1645 nm

    Microsoft Academic Search

    Lachlan Harris; David Ottaway; Peter J. Veitch

    2011-01-01

    We describe the measurement of the Verdet constant of undoped and Er-doped crystalline YAG and tellurite glass at 1645 nm. The undoped YAG value is compared to those measured using visible light. We show that the paramagnetic nature of Er reduces the Verdet constant but that the decrease is probably not significant for the typical Er doping levels used in

  14. Electrical conductivity of gamma-irradiated V2O5 doped lithium disilicate glasses doped and their glass-ceramics derivatives

    Microsoft Academic Search

    S. Abd El All; F. M. Ezz-Eldin

    2010-01-01

    Some physical properties of the lithium disilicate (Li2Si2O5) glasses doped with different ratios of V2O5 were investigated before and after gamma-rays irradiation. Increasing V2O5 ratio causes remarkable changes in the properties studied. The observed variations in the properties may be correlated with the changes in internal glass network with changes in the chemical composition. Vanadium ions are believed to be

  15. Electrical conductivity of gamma-irradiated V 2O 5 doped lithium disilicate glasses doped and their glass–ceramics derivatives

    Microsoft Academic Search

    S. Abd El All; F. M. Ezz-Eldin

    2010-01-01

    Some physical properties of the lithium disilicate (Li2Si2O5) glasses doped with different ratios of V2O5 were investigated before and after gamma-rays irradiation. Increasing V2O5 ratio causes remarkable changes in the properties studied. The observed variations in the properties may be correlated with the changes in internal glass network with changes in the chemical composition. Vanadium ions are believed to be

  16. Study of vibrational spectroscopy, linear and non-linear optical properties of Sm3+ ions doped BaO-ZnO-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Nanda, Kirti; Kundu, R. S.; Sharma, Sarita; Mohan, Devendra; Punia, R.; Kishore, N.

    2015-07-01

    Samarium oxide doped Barium-Zinc-Borate glasses with compositions xSm2O3-(100-x)[0.1BaO-0.4ZnO-0.5B2O3]; x = 0.0, 0.5, 1.0, 1.5 and 2.0 have been prepared by melt quench technique. The amorphous nature of as-prepared glasses has been ascertained by X-ray diffraction patterns. The observed values of density and molar volume of the glass samples are found to increase with the increase in concentration of Sm2O3. Fourier Transform Infrared spectra of the prepared glasses indicate that Sm2O3 acts as glass modifier. With the increase in Sm2O3 content, BO4 structural units start converting into BO3 structural units. The values of optical energy band gap (Eg), estimated from Tauc's plots, are observed to decrease with the increase in Sm2O3 content. The nonlinear optical properties of glass samples have been investigated by Z-scan method with nanosecond pulsed laser at ?532 nm in both open and close aperture geometries. The values of two photon absorption coefficient (?) and nonlinear refractive index (n2) have been estimated by fitting of experimentally observed data with theoretical models and both are found to increase with the increase in Sm3+ ions concentration in the glass matrix. The total third order nonlinear susceptibility (?(3)) have been calculated and observed to increase with the increase in Sm3+ ions concentration.

  17. The effect of an electric field on the phase separation of Ag-doped glass

    Microsoft Academic Search

    Guoliang Wang; Kaiming Liang; Wei Liu; Jialin Sun; Hua Shao

    2004-01-01

    By means of X-ray diffraction (XRD) and scanning electron microscopy (SEM), the phase separation progress of boracic silicate glass doped with silver upon application of an electric field heat treatment is investigated. The experiment results show that externally applied electric field promotes the phase separation of the glass and influences the size of the droplet phase. We propose a new

  18. Absorption spectra of gamma-irradiation TM-doped cabal glasses

    Microsoft Academic Search

    Samir Y. Marzouk; Fatma H. Elbatal; A. M. Salem; S. M. Abo-Naf

    2007-01-01

    The UV visible absorption spectra of nominally pure and transition metals-doped (Ti --> Cu 0.1%) cabal glasses were measured from 200 to 1000 nm before and after successive gamma irradiation. The absorption spectra of the undoped glass exhibit charge transfer bands due to iron trace impurities which eventually affect the induced absorption due to some transition metals and that due

  19. Study on the preparation and properties of silver-doped phosphate antibacterial glasses (Part I)

    NASA Astrophysics Data System (ADS)

    Ahmed, A. A.; Ali, A. A.; Mahmoud, Doaa A. R.; El-Fiqi, A. M.

    2011-05-01

    Silver-doped phosphate antibacterial glasses were prepared by the melting method. The antibacterial effects of some undoped and silver-doped glasses of compositions 65P 2O 5-10CaO-(25- x) Na 2O, 70P 2O 5-20CaO-(10- x) Na 2Oand (70- x) P 2O 5-30CaO, (where x = 0, 0.5, 1.2 Ag 2O), against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli micro-organisms using agar disk-diffusion assays were investigated. The structures of some glasses were studied by XRD, FT-IR, and UV-VIS spectroscopy. The variation of pH with dissolution rate was studied. The tested silver-free and silver-doped glasses demonstrated different antibacterial effects against the tested micro-organisms. For silver-free glasses, an increase in inhibition zone diameter (zone of no bacterial growth) was seen with the decrease in water pH. Silver-doped glasses showed an increase in inhibition zone diameter with increasing Ag 2O content. The low pH produced by glass dissolution was certainly a critical factor for glass antibacterial effect. The more the phosphate ions released the lower is the pH and the greater the antibacterial effect.

  20. Persistent spectral hole burning studies of europium-doped sodium germanate glass

    SciTech Connect

    Kalluru, Rajamohan R.; Pulluru, Chandra R.; Rami Reddy, B. [Department of Physics, Alabama A and M University, P.O. Box 1268, Normal, Alabama 35762 (United States)

    2004-10-01

    Persistent spectral hole burning has been observed in europium-doped sodium germanate glass. Hole-burning efficiency increased by 85% when the glasses were made in a reduced atmosphere, and hole burning was detected even at room temperature. There is evidence for photochemical as well as photophysical hole-burning mechanisms.

  1. Stark splitting and energy transfer between Dy 3+ Ho 3+ and between Tb 3+ Er 3+ in calcium-lithium borate glass

    Microsoft Academic Search

    Brajesh Sharma; V B Singh; D K Rai; S B Rai

    1998-01-01

    Fluorescence spectrum of Dy3+, Dy3+-Ho3+, Tb3+ and Tb3+-Er3+ doped in calibo glass have been studied using Ar+ and excimer lasers. Non-radiative energy transfer from trivalent dysprosium and terbium (donors) to holmium and erbium (acceptors)\\u000a respectively has been observed on the basis of decrease in the life time of the levels and reduction in fluorescence intensity\\u000a of Dy3+ and Tb3+ on

  2. The double role played by the Gd 2O 3 in the gadolinium-aluminum-borate-bismuthate quaternary glass forming tendency. GdBO 3 crystalline phase

    NASA Astrophysics Data System (ADS)

    Rada, S.; Culea, M.; Rada, M.; Pascuta, P.; Maties, V.; Culea, E.

    2009-11-01

    Glasses and glass-ceramics in the xGd 2O 3·(100 - x)[2Bi 2O 3·B 2O 3·Al 2O 3] system with x = 0, 1, 5, 10, 15, 20, 25, 30, 35, 50 mol% Gd 2O 3 have been prepared by the melt quenching method. The changes of the IR spectral features suggest that the formation of [BO 4] tetrahedra is reduced because the modified [BO 3] units containing one or more B-O-Gd bonds are unable to accept the fourth oxygen. Based on our results, we conclude that the accommodation of the networks with the excess of oxygen is possible by the deformation of Bi-O-Bi linkages, the participation of aluminum atoms as network formers and the intercalation of [BiO 6] and [AlO 4] entities in the [BO 4] chain network. When high Gd 2O 3 content is introduced, more [BO 3] structural units are coupled with gadolinium ions and the accumulation of oxygen can be supported by the formation of new [BO 3] -3 structural units as ortho-borate units. These yield the formation of GdBO 3 crystalline phase which has been confirmed by XRD investigations. Comparing the theoretical and experimental IR spectral characteristic features, we conclude that the prediction of the structural data is good.

  3. 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.

  4. Effect of different Er 3+ compounds doping on microstructure and photoluminescent properties of oxyfluoride glass ceramics

    NASA Astrophysics Data System (ADS)

    Zeng, Fanqing; Ren, Guozhong; Qiu, Xiannian; Yang, Qibin

    2008-07-01

    Four different erbium compounds: Er 2O 3, ErOF, ErF 3 and ErCl 3, doped oxyfluoride glass ceramics were prepared. The microstructure and optical properties of the glasses and glass ceramics were determined by differential scanning calorimetry (DSC), X-ray diffraction (XRD), absorption spectra and luminescence spectra. The influence of four different Er 3+ compounds on the microstructure and optical properties of the glasses and their corresponding glass ceramics was analyzed in detail. The results indicated that upconversion luminescence and ratios of red to green emission of all the samples have close relationship with microstructures and the variety of the Er 3+ compounds. It was concluded that the glass ceramics doped with ErF 3 was the most beneficial for the precipitation of PbF 2 crystallites and had the lowest ratio of red to green emission. The mechanisms of the observed phenomena were discussed.

  5. Up-conversion losses in different erbium-doped laser glasses

    NASA Astrophysics Data System (ADS)

    Denker, B. I.; Galagan, B. I.; Sverchkov, S. E.

    2015-06-01

    Up-conversion can be the main mechanism of energy losses in laser glasses with high concentration of erbium ions. This investigation is devoted to the evaluation of up-conversion parameters in several phosphate and silicate Er-doped glasses. Analysis of the luminescent lifetime shortening at high excitation level has shown that the up-conversion parameters in different glasses can differ by an order of magnitude. The smallest up-conversion was observed in Ba crown silicate glass and Li-Ln-phosphate glass.

  6. Magnetic-field effect on the phonon echoes in a rare-earth-doped glass F. Lerbet and G. Bellessa

    E-print Network

    Boyer, Edmond

    observed phonon echoes in a holmium-doped aluminosilica glass, down to 10 mK, up to 60 kOe, in the acoustic.50K Photon echoes in a rare-earth-doped glass have shown that the optical dephasing rates are enhanced1251 Magnetic-field effect on the phonon echoes in a rare-earth-doped glass F. Lerbet and G

  7. Passive laser Q switches made of glass doped with oxidised nanoparticles of copper selenide

    SciTech Connect

    Yumashev, K V [International Laser Center, Belarus State Technical University, Minsk (Belarus)

    2000-01-31

    Passive Q switching of Nd{sup 3+}:YAG ({lambda} = 1060 nm) and YAlO{sub 3}:Nd{sup 3+} (1340 nm) lasers, as well as of an Er{sup 3+} (1540 nm) glass laser was realised by using glass doped with oxidised nanoparticles of copper selenide. Nonlinear optical properties of the nanoparticles (radius of 25 nm) in a glass matrix were studied by the picosecond absorption spectroscopy technique. (control of laser radiation parameters)

  8. Gamma ray detection using sol-gel glass doped with lanthanide ions.

    PubMed

    Pedroza, G; de Azevedo, W M; Khoury, H J; da Silva, E F

    2002-03-01

    In this work we discuss the synthesis, characterization and the use of rare earth doped silica glass prepared by the sol-gel technique as a gamma radiation detector. We obtain a glass material doped with rare earth ions in a high local symmetry, in contrast to the low symmetry found in glasses produced by conventional melting methods and technologies. The behavior of the luminescence spectra of the excited states of rare earth indicates a strong dependence with gamma radiation doses, where the magnetic dipole transition 5D0-->7F1 of the Eu3+ ions presents an huge enhancement of 900% for irradiation doses up to 400 Gy. PMID:11924582

  9. Laser induced breakdown spectroscopy diagnosis of rare earth doped optical glasses

    SciTech Connect

    Dwivedi, Y.; Thakur, S. N.; Rai, S. B.

    2010-05-01

    In the present work, rare earth (Nd, Eu, Er, Ho) doped oxyfluoroborate glasses were studied using laser induced breakdown spectroscopy (LIBS) technique. It has been observed that rare earth elements other than the doped one also reveal their presence in the spectrum. In addition the spectral lines of elements constituting the glass matrix have also been observed. Different plasma parameters such as plasma temperature and electron density have been estimated. It is concluded that the LIBS is a potential technique to identify simultaneously the light elements (B, O, F) as well as the heavy elements (Fe, Ba, Ca, Eu, Nd, Ho, Er) present in optical glasses.

  10. Luminescence properties of rare earth ions doped glasses excited by broadband lights

    NASA Astrophysics Data System (ADS)

    Ren, Linjiao; Lei, Xiaohua; Chen, Weimin; Du, Xiaoqing; Jin, Lei

    2013-09-01

    The experimental excitations for luminescent glasses are usually monochromatic, but LED chips in applications have an emission bandwidth. In order to investigate the luminescence properties of rare earth ions doped glasses excited by broadband lights, a computational model was presented based on the dependences of excitation wavelengths on emission spectra, chromaticity coordinates and correlated color temperatures (CCTs). The simulations were carried out applying Ce/Tb/Eu co-doped calcium borosilicate glasses as examples. The results show that for the same CCTs, the center wavelengths of chips are different with the excitation wavelengths of fluorescence spectrophotometers.

  11. Study on luminescent property of Tb(3+)-doped silicate nano-scintillating glass.

    PubMed

    Jingwen, Lv; Xu, Yang; Shengchun, Xiao; Tao, Zheng

    2010-03-01

    By optimizing a Tb(3+)-doped silicate nano-scintillating glass matrix, sensitizer and brightening agent components, the processing conditions such as the melting temperature, holding time, atmosphere, and heat treatment were improved, and the temperature of the heat treatment was changed to generate BaF2 nano-crystal in the glass. The resulting nanocrystals have a better rare earth solubility and a lower phonon energy; therefore the luminescent property of Tb(3+)-doped silicate nano-scintillating glass has been noticeably improved. PMID:20355612

  12. Physical, thermal, infrared and optical properties of Nd3+ doped lithium-lead-germanate glasses

    NASA Astrophysics Data System (ADS)

    Veeranna Gowda, V. C.

    2015-01-01

    The structure-property relationships of neodymium doped lithium-lead-germanate glasses were investigated. The density was found to increase with the increase of Nd2O3 concentration and its variation is explained in terms of its molecular mass, structural transformation and packing density. Addition of modifier oxide to lead-germanate glass suggests a decreased free space within the glass matrix, resulting in the formation of stiff network. The increase in glass transition temperature specifies strengthening of glass by forming bridging oxygens. The optical properties of glass were measured employing UV-visible spectroscopy. The refractive index values varied nonlinearly with Nd2O3 concentration and were speculated to depend on the electronic polarizability of oxide glasses. The frequencies of the infrared absorption bands were affected marginally and the absorption peaks revealed that the glass matrix consists of [GeO4/2], [GeO6/2] and [PbO4/2] structural units.

  13. Broadband near-infrared emission from transparent Ni2+-doped silicate glass ceramics

    NASA Astrophysics Data System (ADS)

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

    2007-09-01

    Transparent Ni2+-doped MgO-Al2O3-TiO2-SiO2 glass ceramics were prepared, and the optical properties of Ni2+-doped glass ceramics were investigated. Broadband emission centered at 1320nm was observed by 980nm excitation. The longer wavelength luminescence compared with Ni2+-doped Li2O-Ga2O3-SiO2 glass ceramics is ascribed to the low crystal field hold by Ni2+ in MgO -Al2O3-TiO2-SiO2 glass ceramics. The change in optical signals at the telecommunication bands with or without 980nm excitation was also measured when the seed beam passes through the bulk gain host.

  14. Effects of irradiation on transmittance of cerium doped germanate glasses in the ultraviolet and visible regions

    NASA Astrophysics Data System (ADS)

    Baccaro, S.; Cecilia, A.; Chen, G.; Du, Y.; Montecchi, M.; Wang, H.; Wang, S.

    2002-05-01

    A set of heavy germanate glasses were presented as the host for scintillating rare earths. The glasses consisted of GeO 2, Gd 2O 3, BaO as the main constituents and Ce 2O 3 and Tb 2O 3 for introducing the activating cations Ce 3+ and Tb 3+. Ultraviolet and visible transmittance spectra were measured on glass samples before and after irradiations at different doses to study the effects of ionising radiation on their transmission properties. Irradiated samples were submitted to annealing treatments and their transmittance spectra were compared with respect to their thermal bleaching behaviours. Extraordinary irradiation resistance of Ce 3+ doped glasses was observed after comparison with their counterparts doped with Tb 3+, which is of special significance for their applications in high-energy particle experiments. Possible mechanisms causing the positive effect of cerium doping was discussed in terms of its special valence electron orbital configuration.

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

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    Lead fluoroborate glasses were prepared by the melt-quenching technique and characterized in terms of (micro)structural and electrical properties. The study was conducted on as prepared as well as temperature- and/or electric field-treated glass samples. The results show that, in the as-prepared glassy-state materials, electrical conductivity improved with increasing the PbF2 glass content. This result involves both an increase of the fluoride charge carrier density and, especially, a decrease of the activation energy from a glass structure expansion improving charge carrier mobility. Moreover, for the electric field-treated glass samples, surface crystallization was observed even below the glass transition temperature. As previously proposed in literature, and shown here, the occurrence of this phenomenon arose from an electrochemically induced redox reaction at the electrodes, followed by crystallite nucleation. Once nucleated, growth of ?-PbF2 crystallites, with the indication of incorporating reduced lead ions (Pb+), was both (micro)structurally and electrically detectable and analyzed. The overall crystallization-associated features observed here adapt well with the floppy-rigid model that has been proposed to further complete the original continuous-random-network model by Zachariasen for closely addressing not only glasses' structure but also crystallization mechanism. Finally, the crystallization-modified kinetic picture of the glasses' electrical properties, through application of polarization/depolarization measurements originally combined with impedance spectroscopy, was extensively explored.

  16. [Spectroscopic study on the interaction of glass matrixes and nanoparticles in Tm3+ doped oxyfluoride glass ceramics].

    PubMed

    Zhang, Xiang-Yu; Li, Lin; Gao, Dang-Li; Zheng, Hai-Rong

    2009-10-01

    Fluorescence emission spectra from Tm3+ in crystal phase and glass phase were separated under selective excitation of 1D2 level in Tm3+ doped transparent oxyfluoride glass ceramics containing LaF3 nanocrystals. Emissions from the crystal phase and from the glass phase were detected. The influence of the interaction between glass matrix and nanocrystals on the optical characteristics of Tm3+ ions in the two different local environments was investigated. The results indicate that the increase in nanocrystal size results in a decrease in the impact of oxides glass on Tm3+ in the crystal phase, and an enhancement of the impact of nanocrystals on Tm3+ in the glass phase. For smaller nanoparticles, the emission efficiency of Tm3+ ions in the crystal phase was reduced, and the influence of nanocrystals on the ions in the glass phase was reduced too. The larger the nanocrystal size, the weaker the influence of oxide glass on the Tm3+ ions in the crystal phase, and the better performance of fluorescence emission. It was also found that the content of SiO2 in glass matrix could affect the emission efficiency of Tm3+ in both environments. PMID:20038050

  17. Application to Temperature Sensor Based on Green Up-Conversion of Er3+ Doped Silicate Glass

    PubMed Central

    Li, Chengren; Dong, Bin; Ming, Chengguo; Lei, Mingkai

    2007-01-01

    The green up-conversion emissions centered at the wavelengths of about 534nm and 549nm of the Er3+ doped silicate glass were recorded, using a 978 nm semiconductor laser diode (LD) as an excitation source. The fluorescence intensity ratio (FIR) of the green up-conversion emissions at about 534nm and 549nm in the Er3+ doped silicate glass was studied as a function of temperature over the temperature range of 296K-673K. The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0023K-1 and 0.8K, respectively. It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+ doped silicate glass could play a major role in temperature measurement.

  18. Crystal growth and optical properties of CdS-doped lead silicate glass

    SciTech Connect

    Liu Hao [Key Laboratory for Silicate Materials Science and Engineering of Ministry of Education, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Liu Qiming [Key Laboratory for Silicate Materials Science and Engineering of Ministry of Education, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Zhao Xiujian [Key Laboratory for Silicate Materials Science and Engineering of Ministry of Education, Wuhan University of Technology, Wuhan, Hubei 430070 (China)]. E-mail: zhaoxj@public.wh.hb.cn

    2007-01-15

    The crystal growth and optical properties of CdS microcrystallite-doped lead silicate glass is investigated in this paper. The existence of CdS nanocrystals was confirmed via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results reveal that a two-stage heat-treat procedure can produce a better size distribution of CdS nanocrystals than a one-stage heat-treat procedure in glasses. The second harmonic generation (SHG) from the base glass and CdS microcrystallite doped glasses was observed, and the effects of the heat treatments and the thermal poling temperature on the crystallization of CdS and second-order harmonic (SH) intensity were discussed, respectively. It is indicated that samples doped with CdS microcrystallite showed larger SH intensity than that of the base glass. Use of a higher thermal poling temperature than the glass transformation temperature does not result in a good SH intensity in glasses.

  19. Structural evaluation and shielding behavior of gamma irradiated vanadium doped silicophosphate glasses

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    Ultraviolet and visible spectroscopic studies of base undoped and V2O5-doped sodium silicophosphate glasses were carried out in order to characterize the valence states of vanadium ions in such host mixed glass forming oxides. The same spectroscopic measurements were repeated after subjecting the glass to gamma irradiation with a dose of 8 Mrad (8 × 104 Gy). The base glass without V2O5 reveals an UV absorption band which is related to the presence of unavoidable trace iron impurities within the chemicals used for the preparation of this glass. V2O5-doped glasses exhibit extended UV-visible absorption spectra which are attributed to the collective presence of vanadium ions in three possible valencies V3+, V4+ and V5+ with the lower valence predominating. Infrared absorption spectra of the prepared samples indicate the combined presence of vibrational bands due to the sharing of both phosphate and silicate networks in the IR spectra. The addition of V2O5 in the doping level (0.1-3%) did not cause obvious changes in the IR spectra. Gamma irradiation produces noticeable but limited UV-visible spectral variations which show some shielding behavior in some cases. X-ray diffraction technique was applied to confirm the amorphous nature of the prepared glasses. ESR spectral data confirm the optical spectra results indicating the presence of both V3+ and V4+ ions in measurable percent.

  20. A novel ionizing radiation sensor utilizing radiophotoluminescence in silver-doped phosphate glass

    NASA Astrophysics Data System (ADS)

    Nanto, H.; Miyamoto, Y.; Ohno, T.; Ikeguchi, T.; Hirasawa, K.; Takei, Y.; Kurobori, T.; Yamamoto, T.; Iida, T.

    2014-03-01

    Silver (Ag+) doped phosphate glass exhibits an intense photoluminescence (PL) when the non-irradiated Ag+-doped phosphate glass is excited with about 230 nm ultra-violet light. In x-ray irradiated glass, intense radiophotoluminescense (RPL) is observed when the irradiated glass is excited with about 340 nm ultra-violet light. It is found that the RPL spectrum includes two emission bands such as blue emission band peaked at about 460 nm (lifetime: about 6.6 ns) and yellow RPL emission band peaked at about 560 nm (lifetime : about 2.2?s). The PL intensity is decreased with increasing x-ray irradiation dose, while the RPL intensity is increased with x-ray absorbed dose. For the annealing of x-ray irradiated glass at 523 K, the RPL intensity is decreased with annealing, while the PL intensity is increased with annealing. The RPL is vanished and the PL is recovered at original intensity by annealing at 523 K for 40 min. This means that there is a complementary relationship between the PL and RPL on irradiation and heat-treatment processes. The RPL intensity is increased with increasing the x-ray absorbed dose in the range from 0.01 mGy to about 20 Gy, showing that the Ag+-doped phosphate glass can be useful for individual radiation monitoring and environmental radiation monitoring. On the basis of such potentiality of glass as the dosimeter, the application of Ag+-doped phosphate glass on environmental radiation monitoring is discussed and the RPL response of the glass for ?- particle and heavy-particle (He, C, Fe particle) irradiation is demonstrated.

  1. Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium

    PubMed Central

    Paßlick, C.; Müller, O.; Lützenkirchen-Hecht, D.; Frahm, R.; Johnson, J. A.; Schweizer, S.

    2011-01-01

    The structure/property relationships of fluorochlorozirconate glass ceramics as a function of divalent and trivalent europium (Eu) co-doping and thermal processing have been investigated; the influence of doping ratio on the formation of barium chloride (BaCl2) nanocrystals therein was elucidated. X-ray absorption near-edge structure spectroscopy shows that the post-thermal annealing changes the Eu valence of the as-poured glass slightly, but during the melting process Eu3+ is more strongly reduced to Eu2+, in particular, when doped as a chloride instead of fluoride compound. The Eu2+-to-Eu3+ doping ratio also plays a significant role in chemical equilibrium in the melt. X-ray diffraction measurements indicate that a higher Eu2+ fraction leads to a BaCl2 phase transition from hexagonal to orthorhombic structure at a lower temperature. PMID:22275772

  2. Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium

    SciTech Connect

    Passlick, C. [Centre for Innovation Competence SiLi-nano registered , Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale) (Germany); Mueller, O.; Luetzenkirchen-Hecht, D.; Frahm, R. [Bergische Universitaet Wuppertal, Gaussstrasse 20, 42097 Wuppertal (Germany); Johnson, J. A. [Department of Biomedical Engineering, University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States); Schweizer, S. [Centre for Innovation Competence SiLi-nano registered , Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale) (Germany); Fraunhofer Center for Silicon Photovoltaics CSP, Walter-Huelse-Str. 1, 06120 Halle (Saale) (Germany)

    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. 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.

  4. Origin of broadband near-infrared luminescence in bismuth-doped glasses.

    PubMed

    Sokolov, V O; Plotnichenko, V G; Dianov, E M

    2008-07-01

    Interstitial negative-charged bismuth dimers, Bi(-)(2) and Bi(2-)(2), are suggested as a model of broadband IR luminescence centers in bismuth-doped glasses. The model is based on quantum-chemical calculations of equilibrium configurations, absorption, luminescence, and luminescence excitation spectra of the dimers in an alumosilicate network and is supported by IR luminescence observed for the first time, to our knowledge, in bismuth-doped polycrystalline magnesium cordierite. PMID:18594674

  5. Waveguided visible lasing effects in a dye-doped sol-gel glass film

    Microsoft Academic Search

    I. Finkelstein; S. Ruschin; Y. Sorek; R. Reisfeld

    1997-01-01

    We report the first laser action in wavelength films of dye-doped sol-gel glass. Rhodamine B (RB)-doped films were prepared that were pumped by frequency-doubled Nd:YAG laser light focused by means of cylindrical lens. Fresnel back-reflections of the order of a few percent at the edge of the film provided sufficient feedback to change significantly the characteristics of the emitted light.

  6. Highly doped phosphate glass fibers for fiber lasers and amplifiers with applications

    NASA Astrophysics Data System (ADS)

    Chavez-Pirson, Arturo

    2010-10-01

    Rare-earth doped fiber lasers and fiber amplifiers are highly attractive due to their efficiency, compactness, and, particularly, for their potential to various applications including communication systems, biomedical equipment, materials processing, LIDAR, and fiber-optic sensing. At the heart of these devices is the active fiber - most commonly based on silica host glass. However, the ability to dope silica glass fibers with high concentrations of erbium is limited due to clustering and nonlinear up-conversion - both of which degrade the efficiency of the gain fiber. Over many years, we have focused on developing highly doped phosphate glass fibers. The erbium concentrations can reach 4-5% weight erbium concentration without any negative effect to the optical gain. As a result, highly erbium doped phosphate glass fibers can produce large gain per unit length (typically 5 dB/cm) [1, 2]. This characteristic is a key enabler for a variety of optical devices that can make use of high optical gain in a short length - most notably high power single frequency fiber lasers and short length fiber amplifiers. In this presentation, we focus on two applications of the highly doped phosphate fiber. One is a high power, narrow linewidth single frequency fiber laser. The second is a fiber amplifier for coherent LIDAR applications capable of power scaling transform limited pulses without deleterious nonlinear effects. Both are examples of how this type of active fiber can lead to unique and superior performance.

  7. Physical and optical properties of Pr6O11 doped zinc fluoroborate glass

    NASA Astrophysics Data System (ADS)

    PrajnaShree, M.; Wagh, Akshatha; Raviprakash, Y.; Bhat, Sangeetha G.; Kamath, Sudha D.

    2013-06-01

    Praseodymium (Pr3+) doped zinc fluoroborate glasses with the chemical composition [(mol%)30ZnF2-20TeO2-(50-x)B2O3-xPr6O11] (where x = 0.0, 0.1, 0.5, 1.0 and 1.5 mol %) have been prepared by conventional melt quenching technique. The physical and optical parameters like density, refractive index, molar volume, and oscillator strength of these glasses were calculated as a function of dopant concentration. The densities and refractive indices of these glasses were found to be in the range 2 g/cm3 - 2.67 g/cm3 and 1.644 - 1.73 respectively. Stability of glass doped with 1 mol % of Pr3+ was found to be 120.

  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. Preparation of silica glass doped with nitrogen by modified chemical vapor deposition

    Microsoft Academic Search

    L. G. Levit; M. A. Eronyan; Yu. N. Kondratiev

    2000-01-01

    A thermodynamic analysis of the doping of silica glass with nitrogen by the chemical vapor deposition methods has been carried\\u000a out. The fundamental differences are revealed between the plasma chemical vapor deposition and modified chemical vapor deposition\\u000a methods. The basic parameters of nitrogen introduction into silica glass are determined by thermodynamic calculations. It\\u000a is found that the main factor that

  10. Luminescence properties of Tb(3+)-doped borosilicate scintillating glass under UV excitation.

    PubMed

    Zuo, Chenggang; Zhou, Zhihua; Zhu, Ligang; Xiao, Anguo; Chen, Yuandao; Zhang, Xiangyang; Zhuang, Yongbing; Li, Xiaoyang; Ge, Qizhi

    2015-08-01

    Transparent Li2O-BaO-La2O3-Al2O3-B2O3-SiO2 glasses doped with Tb(3+) ion were prepared by high temperature melting method. Luminescence properties of Tb(3+)-doped borosilicate glasses have been investigated by transmission, excitation, emission and luminescence decay measurements. The transmission spectrum shows the glass has good transmittance in the visible region. Under the 236nm UV excitation the intense green emission from (5)D4 level is observed in Tb(3+)-doped borosilicate glass, comparable in intensity to the violet-blue emission starting from the (5)D3 level. The green emission intensity of Tb(3+) ion firstly increases and then decreases with the decreasing B2O3/SiO2 ratio in glass matrix. (5)D4?(7)FJ (J=6, 5, 4 and 3) transitions of Tb(3+) ion in borosilicate glass are greatly enhanced with increasing concentration of Tb(3+) through the cross relaxation [Tb(3+) ((5)D3)+Tb(3+) ((7)F6)?Tb(3+) ((5)D4)+Tb(3+) ((7)F0)] between two Tb(3+) ions. Luminescence decay time of 2.13ms is obtained for the emission transitions starting from (5)D4 level in 2.5Li2O-20BaO-20La2O3-2.5Al2O3-20B2O3-35SiO2-0.5Tb4O7 glass. The results show that Tb(3+)-doped borosilicate glasses would be potential candidates for scintillating material for static X-ray imaging. PMID:25863031

  11. New high-density fluoride glasses doped with CeF 3

    Microsoft Academic Search

    Wancheng Zou; Steve W. Martin; Dave Schwellenbach; John Hauptman

    1995-01-01

    Fluoride glasses have very good optical transparency. With reasonably high density, they may serve as good candidates for fast scintillators. In this work, a group of high-density fluoride glasses has been developed and doped with CeF3. The density, index of refraction, chemical stability, ultraviolet (UV)\\/visible transmission, fluorescence spectra and decay time were measured, and the effects of various components on

  12. Absorption spectra of gamma-irradiation TM-doped cabal glasses

    Microsoft Academic Search

    Samir Y. Marzouk; Fatma H. Elbatal; A. M. Salem; S. M. Abo-Naf

    2007-01-01

    The UV–visible absorption spectra of nominally pure and transition metals-doped (Ti?Cu 0.1%) cabal glasses were measured from 200 to 1000nm before and after successive gamma irradiation. The absorption spectra of the undoped glass exhibit charge transfer bands due to iron trace impurities which eventually affect the induced absorption due to some transition metals and that due to the host base

  13. Sol-Gel synthesis of an optical silica glass doped with rare-earth elements

    Microsoft Academic Search

    N. N. Khimich; G. M. Berdichevskii; E. N. Poddenezhnyi; V. V. Golubkov; A. A. Boiko; V. M. Ken’ko; O. B. Evreinov; L. A. Koptelova

    2007-01-01

    An optical quality silica glass doped with Er3+, Yb3+ and Lu3+ ions is synthesized by the sol-gel method. Virtually unavoidable clusterization of rare-earth elements that occurs upon introduction\\u000a of lanthanide salts into a sol-gel system and leads to concentration quenching of luminescence of the glass is eliminated\\u000a through the use of rare-earth phosphate complexes that are chemically bound to the

  14. Piezooptical effects in the tellurite glasses doped by europium and gold

    Microsoft Academic Search

    L. R. P. Kassab; K. J. Plucinski; M. Piasecki; K. Nouneh; I. V. Kityk; A. H. Reshak; R. de A Pinto

    2008-01-01

    We present the temperature dependence of piezooptical coefficients for three samples of TeO2–GeO2–PbO glasses doped with 0.5% of Eu2O3, 0.5% and 1% of Au2O3, after different thermoannealing times. We have established that there exist two temperatures singularities – minima in the range 655–695K and maxima – at 850K. It is crucial that for the glasses annealed during 61h, at temperatures

  15. Integrated optical amplifiers based on rare-earth doped (red) oxide glasses

    Microsoft Academic Search

    Giancarlo C. Righini; Massimo Brenci; Guaktiero N. Conti; Stefano Pelli; Maurizio Ferrari; Marco Bettinelli; Adolfo Speghini; Baojiu Chen

    2003-01-01

    Oxide glasses have been used since long time to host a number of active compounds, first of all rare-earth (RE) ions, for lasing. Recently, the advantages offered by guided-wave format, namely the small size, the high pump power density, and the larger flexibility in design and fabrication, led to the development of fiber lasers and amplifiers based on Er3+-doped glasses.

  16. Apatite forming ability and cytocompatibility of pure and Zn-doped bioactive glasses.

    PubMed

    Oudadesse, H; Dietrich, E; Gal, Y L; Pellen, P; Bureau, B; Mostafa, A A; Cathelineau, G

    2011-06-01

    The use of bone grafts permits the filling of a bone defect without risk of virus transmission. In this work, pure bioactive glass (46S6) and zinc-doped bioactive glass (46S6Zn10) with 0.1 wt% zinc are used to elaborate highly bioactive materials by melting and rapid quenching. Cylinders of both types of glasses were soaked in a simulated body fluid (SBF) solution with the aim of determining the effect of zinc addition as a trace element on the chemical reactivity and bioactivity of glass. Several physico-chemical characterization methods such as x-ray diffraction, Fourier transform infrared spectroscopy and nuclear magnetic resonance methods, with particular focus on the latter, were chosen to investigate the fine structural behaviour of pure and Zn-doped bioactive glasses as a function of the soaking time of immersion in SBF. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to measure the concentrations of Ca and P ions in the SBF solution after different durations of immersion. The effect of the investigated samples on the proliferation rate of human osteoblast cells was assessed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and tested on two different sizes of pure and zinc-doped glasses in powder form, with particle sizes that ranged between 40 to 63 µm and 500 to 600 µm. The obtained results showed the delay release of ions by Zn-doped glass (46S6Zn10) and the slower CaP deposition. Cytotoxicity and cell viability were affected by the particle size of the glass. The release rate of ions was found to influence the cell viability. PMID:21505231

  17. Fabrication of Sn-doped zinc phosphate glass using a platinum crucible

    Microsoft Academic Search

    Hirokazu Masai; Toshiro Tanimoto; Takumi Fujiwara; Syuji Matsumoto; Yoshihiro Takahashi; Yomei Tokuda; Toshinobu Yoko

    The authors investigate the structural change of a ZnO–P2O5 sintered matrix for the preparation of SnO-doped zinc phosphate (SZP) glass using a platinum crucible. Heat treatment of zinc oxide and ammonium phosphate at 800°C causes the formation of a Zn2P2O7-like species, which is effective in preventing damage to the platinum crucible. Although the thermal property of the glass was affected

  18. Modulation-doped silicate glass deposited by low-pressure chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Ilg, M.; Kraxenberger, M.; Uram, K.; Sandler, N.; Parks, C.; Nguyen, S.

    1998-11-01

    We demonstrate the synthesis of modulation-doped silicate glass. Secondary ion mass spectroscopy measurements show the B and P concentrations to strongly oscillate on a nanometre-scale. This finding is confirmed by scanning-electron microscopy. Finally we show that this novel type of material has gap-fill characteristics superior to those of conventional borophosphosilicate glass currently in use in the semiconductor industry.

  19. Synthesis and optical properties of CsC1-doped gallium-sodium-sulfide glasses

    SciTech Connect

    Hehlen, Markus P [Los Alamos National Laboratory; Bennett, Bryan L [Los Alamos National Laboratory; Williams, Darrick J [Los Alamos National Laboratory; Muenchausen, Ross E [Los Alamos National Laboratory; Castro, Alonso [Los Alamos National Laboratory; Tornga, Stephanie C [Los Alamos National Laboratory

    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.

  20. Rare-earth ion doped lead- and cadmium-free bismuthate glasses

    NASA Astrophysics Data System (ADS)

    Lin, H.; Pun, E. Y. B.; Chen, B. J.; Zhang, Y. Y.

    2008-03-01

    Rare-earth ion doped bismuthate (LZBB) glasses without traditional glass formers, lead and cadmium, have been attempted to prepare. In Er3+ doped LKBB glass system, Judd-Ofelt parameters ?2, ?4, and ?6 have been derived to be 3.48×10-20, 9.47×10-21, and 1.01×10-20cm2, respectively, which shows a medium symmetry of the ligand field in the site occupied by Er3+ and a less covalent environment of Er3+. Effective 1.53?m fluorescence was recorded and the peak emission cross section is proved to be more than 9.0×10-21cm2, which is much higher than those in phosphate, silicate, germanate, and tellurite glasses and beneficial to achieving powerful stimulated emission of Er3+ in LZBB glass system. Pr3+, Tm3+, and Ho3+ doped LZBB glasses with the maximum phonon energy of only ˜600 cm-1 are potential candidates for developing O-, S-, and U-band amplifiers and medical lasers.

  1. 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.

  2. 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 of a two-prong investigation of new tellurite glasses: a Raman study that provides detail information durability make them promising candidates for fiber laser and optical amplifier applications [1

  3. Absorption and Luminescence of Novel PbS-QUANTUM-DOT-DOPED Alkali-Silicate Glasses

    NASA Astrophysics Data System (ADS)

    Loiko, P. A.; Yumashev, K. V.; Rachkovskaya, G. E.; Zakharevich, G. B.

    2013-05-01

    Optical absorption and photoluminescence of novel PbS-quantum-dot-doped alumino-alkali-silicate glasses was investigated. PbS nanocrystals with an average diameter of 3.3-5.4 nm were obtained by heat-treatment of the as-cast glass. An influence of temperature (490-510 °C) and duration (10-80 h) of heat-treatment on the optical properties of the glasses was studied. A possibility to shift the maximum of 1S-1S excitonic absorption peak in the spectral range of 0.85-1.4 ?m was demonstrated.

  4. 1.8 ?m emission of highly thulium doped fluorophosphate glasses

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    A new type of fluorophosphate glasses with high thulium doping concentration (up to 10 mol % Tm3+) is investigated. The intensive 1.8 ?m fluorescence is demonstrated with lower concentration quenching. On the basis of the measured Raman spectroscopy, it is revealed that the glass structure will be changed when adding Tm3+ ions into fluorophosphate glasses. Besides, the Judd-Ofelt parameters and radiative properties are calculated and discussed based on Judd-Ofelt theory. And the absorption and emission cross-sections of F34?H36 transition are also calculated by using McCumber and Beer-Lambert theories.

  5. Effects of rare-earth doping on femtosecond laser waveguide writing in zinc polyphosphate glass

    SciTech Connect

    Fletcher, Luke B.; Witcher, Jon J.; Troy, Neil; Krol, Denise M. [Department of Applied Science, University of California Davis, Davis, California 95616 (United States); Reis, Signo T.; Brow, Richard K. [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States)

    2012-07-15

    We have investigated waveguide writing in Er-Yb doped zinc polyphosphate glass using a femtosecond laser with a repetition rate of 1 KHz. We find that fabrication of good waveguides requires a glass composition with an O/P ratio of 3.25. The dependence on laser writing parameters including laser fluence, focusing conditions, and scan speed is reported. Waveguide properties together with absorption and emission data indicate that these glasses can be used for the fabrication of compact, high gain amplifying devices.

  6. Sodiumand silver phosphate glasses doped with chlorides of Fe, Mn and Zn

    Microsoft Academic Search

    S. S. Das; V. Srivastava

    2007-01-01

    A number of samples of sodium and silver phosphate glasses doped with\\u000a various compositions of some transition metals viz. iron, manganese and zinc\\u000a chlorides alongwith undoped samples of sodium and silver phosphate glasses\\u000a were synthesized and characterized by X-ray diffraction, IR spectral, electrical\\u000a conductivity and differential scanning calorimetry (DSC). The glass transition\\u000a temperature (T\\u000a g)\\u000a and crystallization temperature (T\\u000a c)

  7. Promethium-doped phosphate glass laser at 933 and 1098 nm

    NASA Astrophysics Data System (ADS)

    Krupke, W. F.; Shinn, M. D.; Kirchoff, T. A.; Finch, C. B.; Boatner, L. A.

    1987-12-01

    A promethium (Pm3+) laser has been demonstrated for the first time. Trivalent promethium 147 doped into a lead-indium-phosphate glass étalon was used to produce room-temperature four-level laser emission at wavelengths of 933 and 1098 nm. Spectroscopic and kinetic measurements have shown that Pm3+ is similar to Nd3+ as a laser active ion.

  8. Promethium-doped phosphate glass laser at 933 and 1098 nm

    Microsoft Academic Search

    W. F. Krupke; M. D. Shinn; T. A. Kirchoff; C. B. Finch; L. A. Boatner

    1987-01-01

    A promethium (Pm3+) laser has been demonstrated for the first time. Trivalent promethium 147 doped into a lead-indium-phosphate glass e´talon was used to produce room-temperature four-level laser emission at wavelengths of 933 and 1098 nm. Spectroscopic and kinetic measurements have shown that Pm3+ is similar to Nd3+ as a laser active ion.

  9. Refractive index and density in F- and Cl-doped silica glasses

    SciTech Connect

    Kakiuchida, Hiroshi; Shimodaira, Noriaki; Sekiya, Edson H.; Saito, Kazuya; Ikushima, Akira J. [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511 (Japan); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511, Japan and Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa, Yokohama, Kanagawa 221-8755 (Japan); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511 (Japan)

    2005-04-18

    The refractive index and density of fluorine- and chlorine-doped silica glasses were measured as functions of fictive temperature. The halogen concentrations were observed to have a refractive index or density that is independent of the fictive temperature were found. This implies that these properties are not affected by any heat-treatment conditions.

  10. Modifying the Radiative Quantum Efficiency of Erbium-Doped Glass in Silicon Slot Waveguides

    E-print Network

    Atwater, Harry

    layer of Si-on-insulator (SOI) samples using thermal oxidation and etching with buffered hydrofluoric waveguides with actively emitting slot layers are intriguing since they are expected to produce modal gain sensitized Er slot layers [6]. Er-doped glass is an attractive candidate as an active slot material since

  11. Optical phase conjugation in Rhodamine6G doped boric acid glass

    Microsoft Academic Search

    G. Ravindra Kumar; Bhanu P. Singh; K. K. Sharma

    1989-01-01

    Optical phase conjugation has been demonstrated in Rhodamine-6G doped boric acid glass using a cw argon ion laser. The dependence of the phase conjugated signal on the intensity and wavelength of the pump beam is studied The role of amplitude and phase grating contributions to the phase conjugated signal is discussed.

  12. Resonant photosensitivity in rare-earth-doped glasses and optical fibers

    Microsoft Academic Search

    Matthijs M. Broer

    1993-01-01

    An overview is given of permanent changes in the refractive index and optical transmission which occur in some rare earth-doped inorganic glasses and optical fibers when resonantly excited into specific 4f and 5d manifolds. These phenomena are believed to be electronic in nature involving color centers. They are important for both refractive index grating devices as well as for the

  13. Zeeman splitting and confinement effects in Er3+ -doped nano-glass-

    E-print Network

    Moshchalkov, Victor V.

    Zeeman splitting and confinement effects in Er3+ -doped nano-glass- ceramics in magnetic fields up into Zeeman doublet in external magnetic field. These effects make it possible to flatten the amplification perpendicular to the sample surface area, the Zeeman effect was observed parallel to the applied field. The PL

  14. Depth-resolved nanostructure and refractive index of borosilicate glass doped with Ag nanocrystals

    E-print Network

    Polman, Albert

    Depth-resolved nanostructure and refractive index of borosilicate glass doped with Ag nanocrystals Available online 20 December 2005 Abstract We present an investigation of the Ag-nanocrystal depth profile, XE-AES, and transmission and reflection spectroscopy, we show unambiguously that the Ag nanocrystals

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

    SciTech Connect

    Qiao, Xvsheng, E-mail: qiaoxus@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)] [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Fan, Xianping; Pan, Yu [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)] [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Lotnyk, Andriy; Kienle, Lorenz [Synthesis and Real Structure, Institute for Material Science, Faculty of Engineering, Christian Albrechts University Kiel, Kaiserstr. 2, 24143 Kiel (Germany)] [Synthesis and Real Structure, Institute for Material Science, Faculty of Engineering, Christian Albrechts University Kiel, Kaiserstr. 2, 24143 Kiel (Germany)

    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.

  16. 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.

  17. Thermal analysis, spectral characterization and refractive index studies of lithium doped PbO-ZnO-B{sub 2}O{sub 3} glass

    SciTech Connect

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V. [Department of Physics, Bangalore University, Jnanabarthi campus, Bangalore - 560056 (India); Department of Physics, K.L.E.Society's S. N. College, Bangalore - 560 010 (India); Department of Physics, Bangalore University, Jnanabarthi campus, Bangalore - 560056 (India)

    2012-06-05

    Lithium containing lead zinc borate glasseshave been prepared by melt quenching technique. X-ray diffraction reveals the amorphous nature of the glass. Differential scanning calorimeter (DSC) study was carried out in the temperature range RT to 600 deg. C temperature and found glass transition temperature of these glasses decreases with increase in inter substitution of Pb and Zn lithium content. PZB glasses are stable, IR spectra of these glasses show characteristics band originating from borate groups namely [BO{sub 3}] [BO{sub 4}]and B-O-B stretching vibrations respectively, and found that structure is not affected with effect of lithium content. Refractive index of these glasses are in the range of 1.47 with increasing lithium content refractive index decreases indicating decrease in scattering of light.

  18. Thermal analysis, spectral characterization and refractive index studies of lithium doped PbO-ZnO-B2O3 glass

    NASA Astrophysics Data System (ADS)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2012-06-01

    Lithium containing lead zinc borate glasseshave been prepared by melt quenching technique. X-ray diffraction reveals the amorphous nature of the glass. Differential scanning calorimeter (DSC) study was carried out in the temperature range RT to 600°C temperature and found glass transition temperature of these glasses decreases with increase in inter substitution of Pb and Zn lithium content. PZB glasses are stable, IR spectra of these glasses show characteristics band originating from borate groups namely [BO3] [BO4]and B-O-B stretching vibrations respectively, and found that structure is not affected with effect of lithium content. Refractive index of these glasses are in the range of 1.47 with increasing lithium content refractive index decreases indicating decrease in scattering of light.

  19. Energy transfer kinetics in oxy-fluoride glass and glass-ceramics doped with rare-earth ions

    SciTech Connect

    Sontakke, Atul D.; Annapurna, K. [Glass Science and Technology Section, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata - 700 032 (India)

    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.

  20. Waveguides in Ni-doped glass and glass-ceramic written with a 1 kHz femtosecond laser

    NASA Astrophysics Data System (ADS)

    Hughes, M. A.; Homewood, K. P.; Curry, R. J.; Ohishi, Y.; Suzuki, T.

    2014-07-01

    We report waveguides in Ni-doped Li2O-Ga2O3-SiO2 (Ni:LGS) glass and glass-ceramic (GC) fabricated with a femtosecond (fs) laser with repetition rate of 1 kHz. When the glass is annealed to form a GC, the waveguides are erased. However, in the GC the waveguides are not erased by annealing. In Ni:LGS GC a 415 nm absorption band was created by fs laser waveguide writing due to the creation of Ni nanoparticles with an estimated diameter of a few nm. Raman and photoluminescence spectra of the bulk and waveguide structures were indistinguishable; however, fluorescence decay profiles indicated more long lifetime components in the waveguide compared to the bulk.

  1. Enhancement of light emission from anthracene-doped polyphenylsiloxane glass films containing Ag nanoparticles

    NASA Astrophysics Data System (ADS)

    Shimada, Ryoko; Kimura, Megumi; Tarutani, Naoki; Takahashi, Masahide; Karna, Sanjay; Neogi, Arup

    2014-03-01

    Metal-nanoparticles can induce the localized electric filed in the narrow inter-particle gap. This localization can significantly enhance light emission from fluorescent materials embedding metal nanoparticles. In this phenomenon, the important factors are optical absorption and emission. However, the mechanism of enhancement has not been fully elucidated. In this work, anthracene-doped polyphenylsiloxane (PPS) glass films containing Ag nanoparticles (AgNPs) were prepared for the characterization of enhanced photoluminescence properties. AgNPs of ~ 30nm diameter were synthesized by the polyol process, and mixed in the anthracene-doped PPS glass film. The anthracene-doped PPS thin films of thickness ~ 200 nm, with/without AgNPs, were prepared by spin-casting method. The photoluminescence (PL), measured for these films at room temperature, changed with the anthracene and/or AgNPs concentrations. In the optimum condition, the integrated PL intensity enhancement factor was found to exceed 50.

  2. Photon avalanche upconversion in Ho3+-Yb3+ co-doped transparent oxyfluoride glass-ceramics

    NASA Astrophysics Data System (ADS)

    Babu, P.; Martín, I. R.; Venkata Krishnaiah, K.; Seo, Hyo Jin; Venkatramu, V.; Jayasankar, C. K.; Lavín, V.

    2014-04-01

    The Ho3+-Yb3+ co-doped transparent glass and glass-ceramics containing CaF2 nanocrystals have been prepared. Differential thermal analysis and X-ray diffraction measurements have been made to characterize thermal properties of glass and structural changes in glass-ceramics, respectively. Photon avalanche upconversion has been achieved by exciting the samples at 745 nm at room temperature. An intense green and a weak red upconverted emissions corresponding to the 5S2:5F4 ? 5I8 and 5F5 ? 5I8 transitions, respectively, have been observed. The upconversion intensity has been found to increase with the increase in the size of the fluoride nanocrystals in glass-ceramics. Experimental evidences confirm that the mechanism of upconversion is photon avalanche.

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

    SciTech Connect

    Damas, Pedro [Departamento de Física, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)] [Departamento de Física, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Coelho, João [INESC Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)] [INESC Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Hungerford, Graham [HORIBA Jobin Yvon IBH Ltd., Skypark 5, 45 Finnieston Street, Glasgow G3 8JU (United Kingdom)] [HORIBA Jobin Yvon IBH Ltd., Skypark 5, 45 Finnieston Street, Glasgow G3 8JU (United Kingdom); Hussain, N. Sooraj, E-mail: nandyala.sooraj@fc.up.pt [Departamento de Física, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); INESC Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

    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.

  4. Thermal behaviour of Fe-doped silicate–phosphate glasses

    Microsoft Academic Search

    Irena Wac?awska; Magdalena Szumera

    2010-01-01

    Thermal behaviour and structure of glasses from the SiO2–P2O5–K2O–MgO–CaO system modified by Fe2O3 addition were studied by DSC, XRD and FTIR methods. It has been found that the replacement of MgO and CaO modifiers by Fe2O3 in the structural network of silicate–phosphate glass results in decrease of the glass transition temperature (T\\u000a g) and heat capacity change (?C\\u000a p) accompanying

  5. Compositional investigation of YB(3+)-doped glasses for laser-induced fluorescent cooling applications

    NASA Astrophysics Data System (ADS)

    Murtagh, Michael Thomas

    In this work, a compositional analysis of Yb3+-doped glasses and transparent glass-ceramics was undertaken to determine potential hosts for use in the development of a first-generation optical cryocooler for space-borne remote sensing applications. By pumping to the lower levels of the Yb 3+ 2F5/2 manifold, followed by a thermally-driven population redistribution to higher levels within both manifolds of Yb 3+, net cooling can be achieved by anti-Stokes fluorescence back to the ground state. This thesis focused on glasses in the ZBLAN, BaF2-InF 3-GaF3 (BIG), phosphate and silicate families as well as transparent glass-ceramics which showed great promise for fluorescent cooling. Resonant laser ablation (RLA) experiments showed the effects of electrochemical processing on fluoride glasses in reducing transition metal content which is detrimental to successful fluorescent cooling. Reduction in copper, iron, and chromium content of 18, 4.2, and 5.5 were determined for the ZBLANPb sample via RLA. However, reductions in transition metal content were only 1.9 for copper and a negligible amount for iron and chromium in the BIG glasses due to the interference of reduced indium in the electrochemical processing. The BIG and phosphate glass hosts were found to contain similar mean emission photon energies and larger long-wavelength absorption tails than those of ZBLANPb: Yb3+. The oxyfluoride-based glass-ceramics provided the low phonon energies and higher rare earth concentrations characteristic of fluorides while also containing the high temperature properties of an oxide glass which may be essential in practical fluorescent cooling applications. Optical spectra also revealed a strong potential for MCVD silica as an optical cooler, as sufficient overlap between fluorescence and absorption spectra was present. The BIG-derived glasses were determined to have a theoretical minimum operating temperature of 45 K, compared to 55 K for ZBLANPb, and 50--60 K for the Yb3+-doped glass-ceramic. Infrared camera results showed constant levels of heating at most wavelengths in the transparent glass-ceramic samples, indicating that the temperature increase was independent of the 1.0 mum Yb3+ fluorescence and transition metal content. The presence of heating in Yb3+-doped silica was due to residual OH content in the glass, which had an appreciable absorption band at ˜940 nm.

  6. Emission properties of heavy metal oxide glasses doped with rare-earths

    NASA Astrophysics Data System (ADS)

    Heo, Jong

    2003-07-01

    Emissions at 1.3?m and mid-infrared region from several rare-earths ions doped into PbO-Bi2O3-Ga2O3 glasses were investigated. Lifetime of the Pr3+:1G4 level was 53´s with a quantum efficiency of 9%. Emission at 2.73?m from Er3+, which is normally quenched in oxide glass, was evident and the lifetime of the upper emission level was approximately 900´s. Thermal stability of PbO-Bi2O3-Ga2O3 glass was considerably improved by adding 10 mole % of GeO2. Doping of Tm3+ and Ho3+ showed potentials for S-band fiber-optic amplification.

  7. Structural, thermal and spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application

    SciTech Connect

    Kesavulu, C.R. [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Sreedhar, V.B.; Jayasankar, C.K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Shin, Dong-Soo [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.kr [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of)

    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.

  8. Frequency upconversion in a Pr3+ doped chalcogenide glass containing

    E-print Network

    Paris-Sud XI, Université de

    transparency, high refractive index, and large nonlinear optical properties. Recently, chal- cohalide glass-ceramics and thermal stability, high refractive in- dex n 2.2 at 632.8 nm , and a transmittance window ex- tending fr

  9. Liquid phase sintering of 20Bi(Zn0.5Ti0.5)O 3-80BaTiO3 dielectrics with bismuth-zinc-borate and bismuth borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Shahin, David I.

    Dielectrics in the Bi(Zn0.5Ti0.5)O3-BaTiO 3 system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180°C to reach useful densities. Due to incompatibility of Bi with low-pO2 processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30Bi2O3-30ZnO-40B 2O3 and 50Bi2O3-25B2O 3-25SiO2 (mol%) liquid phase formers. Dielectrics sintered with 1v% borate additions and 5v% additions of either the borate or borosilicate achieved relative densities greater than 95% after sintering at 1000°C for four hours. All compositions retained the relaxor behavior exhibited by pure 20BZT-80BT. Increased borate additions led to greater dielectric constant reductions, while increased borosilicate additions yielded no clear trend in the dielectric constant reduction. Energy densities were estimated between 0.3-0.5 J/cm3; smaller glass additions typically led to larger energy densities. Dielectrics sintered with 1v% borate additions are of interest due to their high relative densities (approx. 96%) and energy densities of approximately 0.5 J/cm3 under 100kV/cm electric fields. Studies of BZT-BT/glass interfaces revealed the formation of crystalline interfacial layers less than 10 microns thick. The borate formed a bismuth titanate phase (likely Bi4Ti3O12) during heating to 700°C, whereas the borosilicate formed a barium silicate phase (likely BaSiO3) during processing to 800°C. Similar phases are expected to be present in the liquid phase sintered dielectrics and likely affect the BZT-BT sintering and dielectric behavior.

  10. Comparison of Er-doped sol-gel glasses with various hosts

    NASA Astrophysics Data System (ADS)

    Xiang, Qing; Zhou, Yan; Lam, Yee Loy; Ooi, Boon Siew; Chan, Yuen Chuen; Kam, Chan Hin

    1999-11-01

    Using the sol-gel process, we prepared three groups of Er-doped glasses, namely, Er-doped Si02-A101.5 (SAB) glass, Er-doped Si02-Ti02-A101.5 (STAE) glass, and Er-doped Si02-Ge02-Al01.5 (SGAE) glass. Various erbium concentration and different host composition under the same processing condition have been studied in order to optimize the material composition to get the strongest fluorescence emission for each material system. It has been found that for SAE glass, the strongest fluorescence emission is obtained when the mole ratio of the three constituent oxides is lOOSiO2 : 20A101.5 2ErO1.5. For the STAE material system, the best composition ratio for the strongest fluorescence emission is 93 Si02 : 7TiO2: 20A101.5 : lErO1.5, whereas the value for SGAE glass is 9OSiO2:lOGeO2 : 2OAlO1.5: 1ErO1.5. But the relative lifetimes were obtained with the recipe lOOSiO2:10A101.5:1ErO1.5 for SAE series, 90 Si02:lOGeO2:1OAlO1.5: 1ErO1.5 for STAE group and 93 Si02:7Ti02:20A101.5:1ErO1.5 for STAE group. Using these recipes, three 20-layer (up to 2.5 ?m) crack-free films have been deposited on silica-on-silicon (SOS) substrates with multiple spin-coating and rapid thermal annealing (RTA). Only the STAE film and the SGAE film are found to guide light. The experimental results show that STAB glasses have higher hydrophilicity than SGAE glasses and SGAE glasses has lower crystallization temperature than STAE glasses. The fact that these waveguiding films emit relatively strong fluorescence around the wavelength of 1.55 ?m implies that such planar waveguides are potential candidates from which integrated optical waveguide amplifiers and lasers operating at the third optical fiber communication window can be fabricated.

  11. 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.

  12. 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

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

    SciTech Connect

    Liu Shimin; Zhao Gaoling; Lin Xiaohua [State Key Lab of Silicon Material, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Ying Hao; Liu Junbo [Hangzhou Bluestar New Material Technical Co. Ltd., Hangzhou 310012 (China); Wang Jianxun [State Key Lab of Silicon Material, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Han Gaorong [State Key Lab of Silicon Material, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)], E-mail: hgr@zju.edu.cn

    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.

  14. Spectroscopic properties of Er doped and Er, Nd codoped fluoride glasses under simulated sunlight illumination

    NASA Astrophysics Data System (ADS)

    Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Kawai, Hiroyuki; Nasu, Hiroyuki; Hughes, Mark A.; Suzuki, Takenobu; Ohishi, Yasutake

    2011-10-01

    We investigated the fluorescence characteristics of Er codoped Nd doped ZBLAN glasses proposed for solar pumped fiber laser (SPFL) under simulated sunlight. Er is used as a sensitizer because it absorbs a part of the ultraviolet and visible light where is no absorption of Nd. Under simulated sunlight illumination, Er singly doped fluoride glass displayed four emission bands with peaks at 550, 848, 977 and 1533 nm attributed to the 4S 3/2- 4I 15/2, 4S 3/2- 4I 13/2, 4I 11/2- 4I 15/2 and 4I 13/2- 4I 15/2 electronic transitions of Er, respectively. The quantum efficiency measurement was carried out using an integrating sphere and under the simulated sunlight excitation showed a maximum of 73% for 0.5 mol.% of ErF 3 in ZBLAN glass. In Nd, Er codoped fluoride glass, the 1.05 ?m emission of Nd was observed under 380 nm excitation what supposes the energy transfer from Er to Nd in ZBLAN glasses as Nd has no absorption at the wavelength. Er, Nd codoped fluoride glasses are promising as a sensitized laser media for solar pumped fiber lasers.

  15. Line patterning of (Sr,Ba)Nb{sub 2}O{sub 6} crystals in borate glasses by transition metal atom heat processing

    SciTech Connect

    Sato, M.; Honma, T.; Benino, Y. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan); Komatsu, T. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan)], E-mail: komatsu@mst.nagaokaut.ac.jp

    2007-09-15

    Some NiO-doped Bi{sub 2}O{sub 3},La{sub 2}O{sub 3}-SrO-BaO-Nb{sub 2}O{sub 5}-B{sub 2}O{sub 3} glasses giving the formation of strontium barium niobate Sr{sub 0.5}Ba{sub 0.5}Nb{sub 2}O{sub 6} (SBN) crystals with a tetragonal tungsten-bronze structure through conventional crystallization in an electric furnace have been developed, and SBN crystal lines have been patterned on the glass surface by heat-assisted (250-300 deg. C) laser irradiation and scanning of continuous-wave Nd:YAG laser (wavelength: 1064 nm). The surface morphology and the quality of SBN crystal lines are examined from measurements of confocal scanning laser micrographs and polarized micro-Raman scattering spectra. The surface morphology of SBN crystal lines changes from periodic bump structures to homogeneous structures, depending on laser scanning conditions. It is suggested that the line patterned at the laser irradiation condition of laser power P=1 W and of laser scanning speed S=1 {mu}m/s in 2NiO-4La{sub 2}O{sub 3}-16SrO-16BaO-32Nb{sub 2}O{sub 5}-30B{sub 2}O{sub 3} glass has a possibility of the orientation of SBN crystals along the laser scanning direction. The present study demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass. - Graphical abstract: This figure shows the polarization optical (a) and confocal scanning laser (b) micrographs for the sample obtained by heat-assisted (300 deg. C) Nd:YAG laser irradiation with a laser power of P=1 W and laser scanning speed of S=1 {mu}m/s in Glass C. The figure demonstrates that the transition metal atom heat processing (i.e., a combination of cw Nd:YAG laser and Ni{sup 2+} ions) is a novel technique for spatially selected crystallization of SBN crystals in glass.

  16. Broadband UV-to-green photoconversion in V-doped lithium zinc silicate glasses and glass ceramics.

    PubMed

    Gao, Guojun; Meszaros, Robert; Peng, Mingying; Wondraczek, Lothar

    2011-05-01

    We report on photoluminescence of vanadium-doped lithium zinc silicate glasses and corresponding nanocrystalline Li2ZnSiO4 glass ceramics as broadband UV-to-VIS photoconverters. Depending on dopant concentration and synthesis conditions, VIS photoemission from [VO4]3 is centered at 550-590 nm and occurs over a bandwidth (FWHM) of ~250 nm. The corresponding excitation band covers the complete UV-B to UV-A spectral region. In as-melted glasses, the emission lifetime is about 34 ?s up to a nominal dopant concentration of 0.5 mol%. In the glass ceramic, it increases to about 45 ?s. For higher dopant concentration, a sharp drop in emission lifetime was observed, what is interpreted as a result of concentration quenching. Self-quenching is further promoted by energy transfer to V4+ centers (2glass and/or synthesis conditions. PMID:21643372

  17. 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

  18. Photoluminescence of Eu3+-, Tb3+-, Dy3+- and Tm3+-doped transparent GeO2 TiO2 K2O glass ceramics

    Microsoft Academic Search

    G. Lakshminarayana; Jianrong Qiu; M. G. Brik; I. V. Kityk

    2008-01-01

    In this paper, we present the photoluminescence properties of Eu3+-, Tb3+-, Dy3+- and Tm3+-doped potassium-titanium-germanate glasses and glass ceramics. Following the x-ray diffraction measurement, the glass structure was established. Compared to Eu3+-, Tb3+-, Dy3+- and Tm3+-doped glasses, their respective glass ceramics show stronger emissions due to the presence of the K2TiGe3O9 crystalline phase. For Eu3+-doped glass and glass ceramics, five

  19. Spectroscopic investigations on Tb3+ doped lead fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Abdul Azeem, P.; Kalidasan, M.; Reddy, R. R.; Ramagopal, K.

    2012-08-01

    This article presents the optical properties of Tb3+ in lead fluoroborate glasses of the type X PbF2·(89-X)B2O3·10 Al2O3·1Tb2O3 (where X=8, 12, 16, 20, 24, 28, 34 and 36). The standard Judd-Ofelt model was applied to the room temperature absorption intensities of Tb3+ (4 f8) to determine the phenomenological intensity parameters ?2, ?4 and ?6. These parameters have been used to calculate radiative transition probabilities (Arad), lifetimes (?R) and branching ratios (?R) for the excited level 5D4. The predicted values of ?R are compared with the measured values for 5D4 level for eight glass compositions (Glass (A-H)). Among the eight-terbium glasses Glass A with 8 mol% of PbF2 (as the optimum content) has revealed an intense green emission with maximum life time and higher quantum efficiency. The stimulated emission cross section ?(?P) is also evaluated for the 5D4?7FJ (J=6, 5, 4 and 3) transitions.

  20. [Effect of critical process parameters on luminescence properties of Eu2+/Dy3+ co-doped high silica luminescence glass].

    PubMed

    Jin, Lei; Lei, Xiao-Hua; Ren, Lin-Jiao; Feng, Yong-An; Du, Xiao-Qing; Chen, Wei-Min

    2014-01-01

    In the present work, Eu2+/Dy3+ co-doped high silica glasses with different process parameters were prepared and the effect of critical process parameters including phase separation temperature, solution concentration and sintering temperature on the luminescence properties of Eu2+/Dy3+ co-doped high silica glasses was investigated by means of measuring pore surface parameters of porous glasses, emission spectra, infrared absorption spectra and densities of high silica glasses. Pore structure parameters of porous glass samples and emission spectra of corresponding high silica glass samples with different phase separation temperatures show that the phase separation temperature has indirect effect on luminescence properties of high silica glass by influencing specific surface area value of corresponding porous glass. Specific surface area of porous glass changes when phase separation temperature changes. High silica glass achieves maximum emission intensity when the maximum specific surface area of porous glass is obtained. Luminescence intensity of high silica glass increases when specific surface area of porous glass increases. Emission spectra of high silica glass samples with different solution concentrations show that the emission intensities of Eu2+ and Dy3+ in high silica glass are enhanced with the increase in the Dy3+ concentration in solution; when the Dy3+ concentration is beyond 0.1 mol x L(-1), the emission intensities of Eu2+ and Dy3+ in high silica glass are both decreased due to the occurring of concentration quench of Dy3+ in the glass. Emission spectra and infrared absorption spectra of high silica glass samples with different sintering temperatures show that the emission intensity of high silica glass is increased with the increase in the sintering temperature because the content of residual hydroxyl groups -OH in the glass is decreased; when the sintering temperature is beyond 1000 degrees C, the high silica glass exhibits crystalline and the luminescence intensity decreases. PMID:24783528

  1. 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.

  2. 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.

  3. Spectral properties and shielding behavior of gamma irradiated MoO3-doped silicophosphate glasses

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    Combined optical and infrared absorption spectra of prepared molybdenum ions in sodium silicophosphate host glasses were investigated before and after gamma irradiation with a dose of 8 Mrad (8×104 Gy). The undoped base sodium silicophosphate glass reveals strong charge transfer ultraviolet absorption but with no visible bands. This strong UV absorption is related to the presence of contaminated trace iron impurities (mainly Fe3+ ions) within the raw materials used for the preparation of this host glass. The MoO3 doped glasses exhibit extra characteristic absorption bands due to the presence of molybdenum ions in three possible valence states, the trivalent, pentavalent and hexavalent forms. Gamma irradiation of the base undoped glass increases the extension of optical absorption within the UV spectrum and produces an extra broad visible band centered at 520 nm. Such radiation-induced spectra are interpreted by assuming the formation of new induced color centers through the absorption of released electrons and formed positive holes during the irradiation process. Also, the possible formation of induced centers through photochemical transformation of some Fe2+ ions to Fe3+ ions by accepting positive holes. The presence of molybdenum ions is assumed to compete with the suggested irradiation reactions by capturing electrons and positive holes during the irradiation process. Infrared absorption spectra of the undoped and MoO3-doped glasses reveal broad IR vibrational bands which are attributed to the presence of combined characteristic vibrational IR modes due to main phosphate and partner silicate groups. The addition of MoO3 (0.5-1.5%) as dopant level causes no changes in the number and position of the main characteristic absorption bands. Gamma irradiation did not cause any marked changes in the IR spectra and the maintainance of the same main IR bands due to the stability of the network containing dual compact two glass-formers units and the presence of molybdenum ions as shielding component. The changes in intensities of some bands are correlated with changes in bond angles and/or bond lengths of some structural units as previously suggested by several authors. E.S.R. data of the MoO3-doped glasses reveal indication of several valence states of molybdenum ions as suggested by optical measurements. The irradiated samples show the change in resonance spectra of high MoO3-doped glasses which can be related to change of some Mo6+ to Mo5+ ions as deduced from optical spectra.

  4. The enhanced two micron emission in thulium doped tellurite glasses

    NASA Astrophysics Data System (ADS)

    Gebavi, Hrvoje; Taccheo, Stefano; Milanese, Daniel

    2013-08-01

    In this work, we demonstrated enhanced infrared thulium emission regarding lifetime values in the novel fluorotellurite glasses in comparison with the traditional TeO2-ZnO-Na2O host. The OH concentration reduction in the novel host material established fast-diffusion regime for the 3F?3H emission while the same emission in 'TZN' host was in the frame of the diffusion-limited regime. The spectroscopic and thermo-mechanical properties of tellurite glasses showed promising features and possibility for fiber drawing.

  5. Optical properties of Eu2O3 doped lead fluoroborate glass

    NASA Astrophysics Data System (ADS)

    Wagh, Akshatha; Mahato, K. K.; Lakshmikanth, R.; Rajaramakrishna, R.; Kamath, Sudha D.

    2012-06-01

    A series of Lead Fluoroborate glasses having composition (mol%) 20 PbF2 - 20 TeO2 - (60-x) B2O3 - xEu2O3 were prepared by doping with different concentration of rare earth element Europium (Eu3+) using the normal melt-quench technique (with x = 0.0, 0.1, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%). The physical parameters like mass density, refractive index, number density, molar refraction, electronic polarizability of theses glasses were found as a function of dopant concentration. The absorption spectra of these glasses were recorded in the UV-VIS range. No sharp edges were found in the spectra, which verify the amorphous nature of theses glasses.

  6. Spectroscopic properties of Er3+ doped lead phosphate glasses for photonic application 4-23-2009

    SciTech Connect

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Guedes, I. [Universidade Federal do Ceara, Ceara, Brazil; Moura, A. L. Moura [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; de Araujo, M. T. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; Jacinto, C. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; Vermelho, M. V. D. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; Loong, C. K. [Sun Yat-Sen University, Guangzhou, China; Boatner, Lynn A [ORNL

    2010-01-01

    The spectroscopic characteristics of Er3+-doped lead phosphate glasses have been investigated, and Judd-Ofelt analysis was used to evaluate the effect of increasing the Er3+ content on the glass matrices. The intensity-dependent Judd=-Ofelt parameters: (4) and (6) remained constant while (2) decreased. Photoluminescence analysis revealed a low up-conversion efficiency through the weak green (530 and 550 nm) and red (660 nm) signals that were present under excitation at 800 nm. The concentration quenching effect on the lifetime of the Er3+: 4I13/2 4I15/2 (1530 nm) transition is also evaluated as a result of the addition of Er3+ to the lead phosphate glass composition. The observed relatively large reduction in the lifetime reflects the significant effects of non-radiative processes in this system. The potential use of these glasses as photonic devices is also discussed.

  7. Low-power continuous-wave nonlinear optics in doped silica glass integrated waveguide structures

    NASA Astrophysics Data System (ADS)

    Ferrera, M.; Razzari, L.; Duchesne, D.; Morandotti, R.; Yang, Z.; Liscidini, M.; Sipe, J. E.; Chu, S.; Little, B. E.; Moss, D. J.

    2008-12-01

    Photonic integrated circuits are a key component of future telecommunication networks, where demands for greater bandwidth, network flexibility, and low energy consumption and cost must all be met. The quest for all-optical components has naturally targeted materials with extremely large nonlinearity, including chalcogenide glasses and semiconductors, such as silicon and AlGaAs (ref. 4). However, issues such as immature fabrication technology for chalcogenide glass and high linear and nonlinear losses for semiconductors motivate the search for other materials. Here we present the first demonstration of nonlinear optics in integrated silica-based glass waveguides using continuous-wave light. We demonstrate four-wave mixing, with low (5 mW) continuous-wave pump power at ? = 1,550 nm, in high-index, doped silica glass ring resonators. The low loss, design flexibility and manufacturability of our device are important attributes for low-cost, high-performance, nonlinear all-optical photonic integrated circuits.

  8. Rare earth-doped integrated glass components: modeling and optimization

    Microsoft Academic Search

    Ole Lumholt; Anders Bjarklev; Thomas Rasmussen; G. Lester

    1995-01-01

    For the integrated optic erbium-doped phosphate silica-amplifier, a comprehensive model is presented which includes high-concentration dissipative ion-ion interactions. Based on actual waveguide parameters, the model is seen to reproduce measured gains closely. A rigorous design optimization is performed, and the influence of variations in the launched pump power, the core cross section, the waveguide length, the erbium concentration, and the

  9. 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

  10. 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.

  11. Europium-doped lead fluoroborate glasses: Structural, thermal and optical investigations

    NASA Astrophysics Data System (ADS)

    Pisarski, W. A.; Pisarska, J.; M?czka, M.; Ryba-Romanowski, W.

    2006-07-01

    Structural, thermal and optical properties of Eu-doped lead fluoroborate glasses have been investigated as a function of PbF 2 concentration. The values of the phonon energy of the host, the glass transition temperature and the fluorescence intensity ratio of the 5D 0- 7F 2 to 5D 0- 7F 1 transition of Eu ions considerably decrease, whereas 5D 0 luminescence lifetime slightly increases with increasing PbF 2 concentration. Incorporation of PbF 2 results in structural and spectroscopic changes around Eu 3+ ions and surrounding ligands, which were analyzed in detail using by Raman, IR, DSC and photoluminescence (PL) spectroscopy.

  12. Leaching of actinide-doped nuclear waste glass in a tuff-dominated system

    SciTech Connect

    Bazan, F.; Rego, J.; Aines, R.D.

    1987-12-31

    A laboratory leaching test has been performed as part of a project to evaluate the suitability of tuff rocks at Yucca Mountain, Nevada, as a site for a high-level nuclear waste repository. Glass samples were placed in water inside tuff vessels, and then the tuff vessels were placed in water inside Teflon containers. Glass-component leach rates and migration through the tuff were measured for samples of the ATM-8 actinide glass, which is a PNL 76-68 based glass doped with low levels of {sup 99}Tc, {sup 237}Np, {sup 238}U, and {sup 239}Pu to simulate wastes. Disc samples of this glass were leached at 90{sup 0}C for 30, 90, and 183 days inside tuff vessels using a natural groundwater (J-13 well-water) as the leachant. Some samples were held by 304L stainless steel supports to evaluate the effect of this metal on the release rate of glass constituents. At the end of each leaching interval, the J-13 water present inside and outside the rock vessel was analyzed for glass components in solution. On the basis of these analyses, boron, molybdenum, and technetium appear to migrate through the rock at rates that depend on the porosity of each vessel and the time of reaction. The actinide elements (uranium, neptunium, and plutonium) were found only in the inner leachate. 8 references, 6 figures, 6 tables.

  13. Crystallization studies on rare-earth co-doped fluorozirconate-based glasses

    PubMed Central

    Paßlick, C.; Johnson, J.A.; Schweizer, S.

    2013-01-01

    This work focuses on the structural changes of barium chloride (BaCl2) nanoparticles in fluorochlorozirconate-based glass ceramics when doped with two different luminescent activators, in this case rare-earth (RE) ions, and thermally processed using a differential scanning calorimeter. In a first step, only europium in its divalent and trivalent oxidation states, Eu2+ and Eu3+, is investigated, which shows no significant influence on the crystallization of hexagonal phase BaCl2. However, higher amounts of Eu2+ increase the activation energy of the phase transition to an orthorhombic crystal structure. In a second step, nucleation and nanocrystal growth are influenced by changing the structural environment of the glasses by co-doping with Eu2+ and trivalent Gd3+, Nd3+, Yb3+, or Tb3+, due to the different atomic radii and electro-negativity of the co-dopants. PMID:23745010

  14. 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.

  15. Promethium-doped phosphate glass laser at 933 and 1098 nm

    Microsoft Academic Search

    W. F. Krupke; M. D. Shinn; T. A. Kirchoff; C. B. Finch; L. A. Boatner

    1987-01-01

    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.

  16. Monte Carlo simulations of homogeneous upconversion in erbium-doped silica glasses

    Microsoft Academic Search

    Jacob L. Philipsen; Anders Bjarklev

    1997-01-01

    Quenching of Er3+ ions by homogeneous energy-transfer upconversion in high-concentration erbium-doped silica glasses has been theoretically investigated, The results indicate that at Er3+ concentrations of 1.0-2.0·1026 m-3 or below, the kinetic limit of strong migration is not reached, and hence the widely accepted quadratic upconversion model is not generally valid. Nevertheless, the results offer an explanation of the experimental observations

  17. Highly efficient high-power thulium-doped germanate glass fiber laser

    Microsoft Academic Search

    Jianfeng Wu; Zhidong Yao; Jie Zong; Shibin Jiang

    2007-01-01

    A 64 W fiber laser at 1.9 mum with a slope efficiency of 68% with respect to the launching pump power at 800 nm was demonstrated in a one-end pump configuration using a piece of 20 cm long newly developed thulium-doped germanate glass double-cladding single-mode fiber. A quantum efficiency of 1.8 was achieved. An output laser power of 104 W

  18. DBR and DFB lasers in neodymium- and ytterbium-doped photothermorefractive glasses.

    PubMed

    Ryasnyanskiy, A; Vorobiev, N; Smirnov, V; Lumeau, J; Glebova, L; Mokhun, O; Spiegelberg, Ch; Krainak, Michael; Glebov, A; Glebov, L

    2014-04-01

    The first demonstration, to the best of our knowledge, of distributed Bragg reflector (DBR) and monolithic distributed feedback (DFB) lasers in photothermorefractive glass doped with rare-earth ions is reported. The lasers were produced by incorporation of the volume Bragg gratings into the laser gain elements. A monolithic single-frequency solid-state laser with a linewidth of 250 kHz and output power of 150 mW at 1066 nm is demonstrated. PMID:24686699

  19. Spectral hole burning and fluorescence in femtosecond laser induced Sm 2+-doped glasses

    Microsoft Academic Search

    Gil Jae Park; Tomokatsu Hayakawa; Masayuki Nogami

    2004-01-01

    The femtosecond laser was used to irradiate sol–gel derived Sm3+-doped Al2O3–SiO2 glasses, in which the Sm3+ was reduced into Sm2+ ions. The fluorescence line narrowing was applied to investigate the coordination sphere of the Sm2+ ion. The spectral hole burning was performed on 7F0?5D0 transition of the Sm2+. The depth and width of the burnt holes were ?27% and ?4cm?1

  20. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C.; Edgar, A.; Varoy, C.; Belev, G.; Wysokinski, T.; Chapman, D.; Sammynaiken, R.; Kasap, S. O.

    2014-02-01

    Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm3+) 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 Sm3+-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm3+-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 Sm2+ to Sm3+ 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 Sm2+ to Sm3+ 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.

  1. Spatially resolved measurement of high doses in microbeam radiation therapy using samarium doped fluorophosphate glasses

    Microsoft Academic Search

    Go Okada; Brian Morrell; Cyril Koughia; Andy Edgar; Chris Varoy; George Belev; Tomasz Wysokinski; Dean Chapman; Safa Kasap

    2011-01-01

    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 Sm3+ --> Sm2+ valence conversion in Sm3+ doped fluorophosphates glasses has been tested for use in x-ray dosimetry for

  2. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    SciTech Connect

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C., E-mail: cyril.koughia@usask.ca; Kasap, S. O. [Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Edgar, A.; Varoy, C. [School of Chemical and Physical Sciences and MacDiarmid Institute, Victoria University of Wellington, Wellington 6140 (New Zealand); Belev, G.; Wysokinski, T.; Chapman, D. [Canadian Light Source, Inc., University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Sammynaiken, R. [Saskatchewan Structural Sciences Centre, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9 (Canada)

    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.

  3. 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...

  4. 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: xfliu@zju.edu.cn, E-mail: qjr@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Junpei; Han, Junbo [Wuhan National High Magnetic field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Qiu, Jianrong, E-mail: xfliu@zju.edu.cn, E-mail: qjr@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    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.

  5. Physical properties of Eu^3+ doped sodium magnesium alumino-silicate glasses studied by light scattering spectroscopy

    Microsoft Academic Search

    Guoqing Shen; Zhandos Utegulov; James P. Wicksted; Abdur Rahman

    2001-01-01

    Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium doped sodium magnesium alumino-silicate glasses (ESMAS) were performed to study the glass structures and optical properties of ESMAS. The linewidth, frequency shift, and intensity of Brillouin peaks were determined to calculate the phonon attenuation, elastic constants, photo-elastic coefficients, and the bond polarizability parameter. The parameters obtained from

  6. Electron, hole and exciton self-trapping in germanium doped silica glass from DFT calculations with self-interactions correction

    Microsoft Academic Search

    Jincheng Du; Louis R. Corrales; Kiril L. Tsemekhman; Eric J. Bylaska

    2007-01-01

    We performed density functional theory (DFT) calculations of electron, hole and exciton self-trapping in germanium doped silica glass to understand the refractive index change in these glasses induced by UV irradiation. The local structure relaxation and excess electron density distribution upon trapping of the above species were calculated. The results show that both trapped exciton and electron are highly localized

  7. Flame Retardancy Behavior of Zinc Borate

    Microsoft Academic Search

    Youming Yang; Xichang Shi; Ruirong Zhao

    1999-01-01

    The effect of boron chloride formation from zinc borate in burn ing PVC was elucidated. By thermodynamic calculation, experiment, and infra red spectrum analysis, the conditions for boron halide formation when PVC was burned were addressed. It is found that when boron halide is produced, the B2O3 glass layer is destroyed and boron is volatilized, which is unfavorable to flame

  8. Piezooptical effects in the tellurite glasses doped by europium and gold

    NASA Astrophysics Data System (ADS)

    Kassab, L. R. P.; Plucinski, K. J.; Piasecki, M.; Nouneh, K.; Kityk, I. V.; Reshak, A. H.; Pinto, R. de A.

    2008-07-01

    We present the temperature dependence of piezooptical coefficients for three samples of TeO 2-GeO 2-PbO glasses doped with 0.5% of Eu 2O 3, 0.5% and 1% of Au 2O 3, after different thermoannealing times. We have established that there exist two temperatures singularities - minima in the range 655-695 K and maxima - at 850 K. It is crucial that for the glasses annealed during 61 h, at temperatures about 850 K, the anomaly of piezooptical coefficient disappears. Simultaneously the minima within the range 655-695 K changed depending on the duration of the thermoannealing which leads to low temperature shift of the minima. Towards lower temperature the piezooptical maxima occurs around 850 K and disappears after the increase of the annealing time. It is also crucial that the values of the piezooptical coefficients decrease with the enhancement of the thermoannealing. The observed temperature dependence with the piezooptical coefficients has a good correlation with the temperature dependences of the DSC. We have found that the pure glasses and glasses doped only by Au 2O 3 and Eu 2O 3 possess the piezooptical coefficients one order less with respect to the samples possessing simultaneously Au 2O 3 and Eu 2O 3.

  9. 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.

  10. FTIR spectra and thermal properties of TiO2-doped iron phosphate glasses

    NASA Astrophysics Data System (ADS)

    Lu, Mingwei; Wang, Fu; Liao, Qilong; Chen, Kuiru; Qin, Jianfa; Pan, Sheqi

    2015-02-01

    Structure and thermal properties of xTiO2·(90 - x) (60P2O5-40Fe2O3)?10CaF2 (x = 0, 5, 10, 15, 20 and 25 mol%) glasses are investigated in detail by Fourier Transform Infrared Spectrum (FTIR) and Differential Thermal Analysis (DTA), respectively. It is found that incorporation of TiO2 increase the density and glass transition temperature of iron phosphate system glass. The increment of doped-TiO2 can also strengthen phosphate network chains due to increasing O/P ratios and more orthophosphate (Q0) units formed in the glass structure at expense of pyrophosphate (Q1) units and metaphosphate (Q2) groups. Moreover, the structure of iron phosphate glass with TiO2 content contain distorted octahedral [TiO6] linked to phosphate unit through Psbnd Osbnd Ti bonds, thus enhanced structure cohesion and increased density obtained. The knowledge provides an improved understanding of the role of TiO2 in the structure of iron phosphate glasses.

  11. 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.

  12. 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.

  13. Electrical conductivity of gamma-irradiated V 2O 5 doped lithium disilicate glasses doped and their glass-ceramics derivatives

    NASA Astrophysics Data System (ADS)

    El All, S. Abd; Ezz-Eldin, F. M.

    2010-01-01

    Some physical properties of the lithium disilicate (Li 2Si 2O 5) glasses doped with different ratios of V 2O 5 were investigated before and after gamma-rays irradiation. Increasing V 2O 5 ratio causes remarkable changes in the properties studied. The observed variations in the properties may be correlated with the changes in internal glass network with changes in the chemical composition. Vanadium ions are believed to be present in three possible valence states V 3+, V 4+ and V 5+, and the ratios of these states depend on glass composition. Observed increase in electrical conductivity is assumed to be related to several parameters including the creation of localized state, which increase the charges carrier to conduction band, increase of the number of nonbridging oxygen's and/ or electron hopping between vanadate ions in different valence states. However, the results indicate that the heat-treatment of amorphous samples accelerate the sequence of formation of lithium metasilicate crystals, causing a decrease in the electrical conductivity. The changes obtained due to gamma-irradiation are correlated to several factors, such as polarization and field strength of the respective cations and to the amount of induced defect centers created upon gamma-irradiation.

  14. Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.

    PubMed

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

    2014-08-14

    The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 ?m emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application. PMID:24747331

  15. Mössbauer spectroscopy of europium-doped fluorochlorozirconate glasses and glass ceramics: optimization of storage phosphors in computed radiography.

    PubMed

    Pfau, C; Paßlick, C; Gray, S K; Johnson, J A; Johnson, C E; Schweizer, S

    2013-05-22

    Eu(2+)-doped fluorochlorozirconate (FCZ) glasses and glass ceramics, which are being developed for medical and photovoltaic applications, have been analysed by Mössbauer spectroscopy. The oxidation state and chemical environment of the europium ions, which are important for the performance of these materials, were investigated. Routes for maximizing the divalent europium content were also investigated. By using EuCl2 instead of EuF2 in the starting material a fraction of about 90% of the europium was maintained in the Eu(2+) state as opposed to about 70% when using EuF2. The glass ceramics produced by subsequent thermal processing contain BaCl2 nanocrystals in which Eu(2+) is incorporated, as shown by the narrower linewidth in the Mössbauer spectrum. Debye temperatures of 147 K and 186 K for Eu(2+) and Eu(3+), respectively, were determined from temperature dependent Mössbauer measurements. The f-factors were used to obtain the Eu(2+)/Eu(3+) ratio from the area ratio of the corresponding absorption lines. PMID:23603535

  16. Mössbauer spectroscopy of europium-doped fluorochlorozirconate glasses and glass ceramics: optimization of storage phosphors in computed radiography

    PubMed Central

    Pfau, C; Paßlick, C; Gray, S; Johnson, JA; Johnson, CE; Schweizer, S

    2013-01-01

    Eu2+-doped fluorochlorozirconate (FCZ) glasses and glass ceramics, which are being developed for medical and photovoltaic applications, have been analysed by Mössbauer spectroscopy. The oxidation state and chemical environment of the europium ions, which are important for the performance of these materials, were investigated. Routes for maximizing the divalent europium content were investigated. By using EuCl2 instead of EuF2 in the starting material a fraction of about 90% of the europium was maintained in the Eu2+ state as opposed to about 70% when using EuF2. The glass ceramics produced by subsequent thermal processing contain BaCl2 nanocrystals in which Eu2+ is incorporated, as shown by the narrower linewidth in the Mössbauer spectrum. Debye temperatures of 147 K and 186 K for Eu2+ and Eu3+, respectively, were determined from temperature dependent Mössbauer measurements. The f-factors were used to obtain the Eu2+/Eu3+ ratio from the area ratio of the corresponding absorption lines. PMID:23603535

  17. Role of glass structure in defining the chemical dissolution behavior, bioactivity and antioxidant properties of zinc and strontium co-doped alkali-free phosphosilicate glasses.

    PubMed

    Kapoor, Saurabh; Goel, Ashutosh; Tilocca, Antonio; Dhuna, Vikram; Bhatia, Gaurav; Dhuna, Kshitija; Ferreira, José M F

    2014-07-01

    We investigated the structure-property relationships in a series of alkali-free phosphosilicate glass compositions co-doped with Zn(2+) and Sr(2+). The emphasis was laid on understanding the structural role of Sr(2+) and Zn(2+) co-doping on the chemical dissolution behavior of glasses and its impact on their in vitro bioactivity. The structure of glasses was studied using molecular dynamics simulations in combination with solid state nuclear magnetic resonance spectroscopy. The relevant structural properties are then linked to the observed degradation behavior, in vitro bioactivity, osteoblast proliferation and oxidative stress levels. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy and scanning electron microscopy-energy-dispersive spectroscopy after immersion of glass powders/bulk in simulated body fluid (SBF) for time durations varying between 1h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the glasses exhibit hydroxyapatite formation on their surface within 1-3h of their immersion in SBF. The cellular responses were observed in vitro on bulk glass samples using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of zinc and strontium released from the glasses is also discussed. PMID:24709542

  18. 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.

  19. 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...

  20. Influence of Nd3+ ions on TL characteristics of Li2O-MO-B2O3 (MO = ZnO, CaO, CdO) glass system

    NASA Astrophysics Data System (ADS)

    Anjaiah, J.; Laxmikanth, C.; Lyobha, Cephas John; Veeraiah, N.; Kistaiah, P.

    2015-02-01

    Thermoluminescence (TL) characteristics of X-ray irradiated pure and doped with Nd3+ ions glasses have been studied in the temperature range 303-573 K; all the pure glasses have exhibited single TL peak at 382, 424 and 466 K, respectively. When these glasses are doped with Nd3+ ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Nd3+-doped glasses mixed with cadmium oxide as modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that neodymium (Nd)-doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  1. Structural and spectroscopic investigations on Eu 3+-doped alkali fluoroborate glasses

    NASA Astrophysics Data System (ADS)

    Marimuthu, K.; Karunakaran, R. T.; Surendra Babu, S.; Muralidharan, G.; Arumugam, S.; Jayasankar, C. K.

    2009-07-01

    Eu 3+-doped alkali fluoroborate glasses B 2O 3-XCO 3-NaF-Eu 2O 3 (where X = Li 2, Na 2, K 2, and Ca, Mg) have been prepared using the conventional melting technique and their structural and optical properties have been evaluated. The XRD pattern of the glasses confirmed the amorphous nature and the FTIR spectra reveal the presence of BO 3 and BO 4 units as their local structures along with the strong OH - groups. From the absorption spectra the bonding parameters have been calculated and confirmed that the Eu-O bonds in the studied glasses are of covalent nature. Judd-Ofelt (JO) analysis has been carried out from the emission spectra. The JO parameters have been used to calculate transition probabilities ( A), lifetime ( ?R) and branching ratios ( ?R) and peak stimulated emission cross-section ( ?PE) for the 5D 0 ? 7F J ( J = 1, 2, 3 and 4) transitions of the Eu 3+ ions. The decay from the 5D 0 level of Eu 3+ ions in the title glasses has been measured and analysed. The lifetime of the 5D 0 level is found to be shorter than the reported glasses which may be due to the presence of OH - groups.

  2. Luminescence and microstructure of Sm2+ ions reduced by x-ray irradiation in Li2O-SrO-B2O3 glass

    Microsoft Academic Search

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

    2008-01-01

    Sm3+-doped Li2O-SrO-B2O3 glass sample was prepared by the conventional melt quenching method in air atmosphere. Sm2+ 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 Sm2+ luminescence intensity on the x-ray irradiation time was investigated. It is found that the

  3. Synthesis and properties of ZnTe and Eu3+ ion co-doped glass nanocomposites

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    In this study, ZnTe (II-VI) semiconductor and Eu+3-ion co-doped borosilicate glass has been prepared in the SiO2-K2O-CaO-BaO-B2O3 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 × 10-6/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 (?cut-off) shifted towards higher wavelength. Excitation spectra were recorded by monitoring emission at 613 nm corresponding to the 5D0 ? 7F2 transition. An intense 394 nm excitation band corresponding to the 7F0 ? 5L6 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 Eu3+ 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. 5D1 ? 7F0 transition is visible only in the samples heat-treated for 30 min and 1 h, which is a characteristic of presence of Eu3+ 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.

  4. Optical evaluation on Nd3+-doped phosphate glasses for O-band amplification.

    PubMed

    Lei, Weihong; Chen, Baojie; Zhang, Xiangling; Pun, Edwin Yun Bun; Lin, Hai

    2011-02-20

    We have fabricated and characterized optically Nd3+-doped phosphate [Li2O-CaO-BaO-Al2O3-La2O3-P2O5 (LCBALP)] glasses for drawing single-mode glass fiber. The 4F3/2?4I13/2 transition emission from the Nd3+ is at the 1.327??m wavelength with a full width at half-maximum of 43?nm, and the spontaneous transition probability and quantum efficiency are calculated to be 1836?s-1 and 52%, respectively. The maximum stimulated emission cross sections for 4F3/2?4I11/2 and 4F3/2?4I13/2 transitions are derived to be 1.82×10(-20)?cm2 and 6.97×10(-21)?cm2, respectively, and the theoretical gain coefficient at the 1.327??m wavelength is evaluated to be 0.182?dB/cm when the fractional factor of the excited neodymium ions equals 0.6, which indicates that Nd3+-doped LCBALP phosphate glasses are potential candidates in developing O-band optical fiber amplifiers. PMID:21343962

  5. New generation high-power rare-earth-doped phosphate glass fiber and fiber laser

    NASA Astrophysics Data System (ADS)

    Wu, Ruikun; Myers, John D.; Myers, Michael J.

    2001-04-01

    High power, high brightness fiber lasers have numerous potential commercial and military applications. Fiber lasers with cladding pump designs represent a new generation of diode pumped configurations that are extremely efficient, have single mode output and may be operated with or without active cooling. Kigre has invented a new family of Er/Yb/Nd phosphate laser glass materials (designated QX) that promise to facilitate a quantum leap in fiber laser technology of this field. The new phosphate glass Rare-Earth doped fiber exhibit many advantages than Silica or Fluoride base fiber, see table.1. Instead of 30 to 50 meters of fused silica with a 50 mm bend radii; Kigre's phosphate glass fiber amplifiers may be designed to be less than 4 meters long .Laser performance and various design parameters, such as the fiber core diameter, NA, inner cladding shape and doping concentration are evaluated. Laser performances was demonstrated for an experimental QX/Er doubled clading fiber commissioned by MIT having 8 micron core, a 240 X 300 micron rectangle shaped inner cladding with 0.4 NA and 500 micron outer clading.. Kigre obtained approximately 2 dB/cm gain from 15cm long fiber under 940nm pumping The same fiber was evaluated by researcher at MIT. They used 975nm pump source. Maximum 270mW output was demonstrated by 30 cm long fiber with Fresnel reflection resonator mirrors. The slope efficiency of absorbed pump power s 47%.

  6. 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. [Department of Physics, Pondicherry University, Kalapet, Puducherry-605 014 (India)

    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.

  7. The Brillouin gain coefficient of Yb-doped aluminosilicate glass optical fibers

    NASA Astrophysics Data System (ADS)

    Dragic, Peter D.; Ballato, John; Morris, Stephanie; Hawkins, Thomas

    2013-07-01

    Provided herein is a detailed analysis of the Brillouin spectroscopy of the ytterbia (Yb2O3) dopant in aluminosilicate glass optical fibers. Yb-doped fiber lasers have become ubiquitous, and the results presented here may be used to design lasers and amplifiers for narrow linewidth systems and applications. It is found, with a high degree of certainty, that Yb2O3 has an acoustic velocity that is lower than that of silica, a Brillouin spectral width (or material acoustic damping coefficient) that is about 80 times greater than that of silica, and photoelastic constants (Pockels' coefficients) that are negative. It is found that the primary influence of ytterbia in concentrations typical of active fibers is to broaden the Brillouin gain spectrum, thereby reducing the peak Brillouin gain. A set of design curves is provided outlining the Brillouin gain coefficient as a function of alumina concentration for several ytterbia concentrations, which can be utilized to design fiber structures with reduced Brillouin gain. The Yb-doped aluminosilicate fiber system is compared to the Yb-doped phosphosilicate system, and a high degree of similarity is found between them at low Al2O3 or P2O5 doping levels. However, for fiber produced utilizing conventional techniques, the phosphosilicates are found to have the potential for lower Brillouin gain since more P2O5 can be reliably incorporated into the glassy matrix.

  8. Physical properties of Eu^3+ doped sodium magnesium alumino-silicate glasses studied by light scattering spectroscopy

    NASA Astrophysics Data System (ADS)

    Shen, Guoqing; Utegulov, Zhandos; Wicksted, James P.; Rahman, Abdur

    2001-03-01

    Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium doped sodium magnesium alumino-silicate glasses (ESMAS) were performed to study the glass structures and optical properties of ESMAS. The linewidth, frequency shift, and intensity of Brillouin peaks were determined to calculate the phonon attenuation, elastic constants, photo-elastic coefficients, and the bond polarizability parameter. The parameters obtained from this study shows that the glass structures become more rigid and ionic with increasing Al content, while the glass structures show more ionic and less rigid with increasing Na concentration. The Judd-Ofelt intensity parameter, ?_6, obtained from absorption measurements agrees with the Brillouin scattering results.

  9. 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

  10. Luminescence properties of Sm(3+)-doped P(2)O(5)-PbO-Nb(2)O(5) glass under high pressure.

    PubMed

    Praveena, R; Venkatramu, V; Babu, P; Jayasankar, C K; Tröster, Th; Sievers, W; Wortmann, G

    2009-01-21

    Samarium doped lead phosphate glass modified with niobium having a composition (in mol%) of 55P(2)O(5)+39.5PbO+5Nb(2)O(5)+0.5Sm(2)O(3) has been prepared by the conventional melt quenching technique. The emission spectra and the decay curves for the (4)G(5/2) level of Sm(3+) ions have been measured as a function of pressure up to 23.6 GPa at room temperature. A discontinuity in the observed shifts and crystal-field splittings as a function of pressure around 9-10 GPa suggests that a phase transition is taking place in the glass matrix. The [Formula: see text], (6)H(7/2) and (6)H(9/2) transitions are shifted towards the lower energy side with magnitudes of -7.1, -7.6 and -5.5 cm(-1) GPa(-1) up to 8.9 GPa (phase 1) and -5.6, -4.9 and -4.4 cm(-1) GPa(-1) beyond 10.3 GPa (phase 2), respectively. A much stronger increase in the splitting of the [Formula: see text] and [Formula: see text] Stark levels with pressure is observed in phase 1 than in phase 2. The lifetime of the (4)G(5/2) level decreases from 2.29 ms (0 GPa) to 0.64 ms (23.6 GPa) with pressure. The decay curves of the (4)G(5/2) level exhibit non-exponential behavior for all the pressures and were fitted by the generalized Yokota-Tanimoto model to probe the nature of the energy transfer process. The best fits with S = 6 indicate that the energy transfer between donor and acceptor is of dipole-dipole type. The crystal-field splitting experienced by the Sm(3+) ions in the title glass are found to be larger than those found in borate, K-Ba-Al phosphate and tellurite glasses. PMID:21817267

  11. Luminescence properties of Sm3+-doped P2O5-PbO-Nb2O5 glass under high pressure

    NASA Astrophysics Data System (ADS)

    Praveena, R.; Venkatramu, V.; Babu, P.; Jayasankar, C. K.; Tröster, Th; Sievers, W.; Wortmann, G.

    2009-01-01

    Samarium doped lead phosphate glass modified with niobium having a composition (in mol%) of 55P2O5+39.5PbO+5Nb2O5+0.5Sm2O3 has been prepared by the conventional melt quenching technique. The emission spectra and the decay curves for the 4G5/2 level of Sm3+ ions have been measured as a function of pressure up to 23.6 GPa at room temperature. A discontinuity in the observed shifts and crystal-field splittings as a function of pressure around 9-10 GPa suggests that a phase transition is taking place in the glass matrix. The \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{5/2}} , 6H7/2 and 6H9/2 transitions are shifted towards the lower energy side with magnitudes of -7.1, -7.6 and -5.5 cm-1 GPa-1 up to 8.9 GPa (phase 1) and -5.6, -4.9 and -4.4 cm-1 GPa-1 beyond 10.3 GPa (phase 2), respectively. A much stronger increase in the splitting of the \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{5/2}} and \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{7/2}} Stark levels with pressure is observed in phase 1 than in phase 2. The lifetime of the 4G5/2 level decreases from 2.29 ms (0 GPa) to 0.64 ms (23.6 GPa) with pressure. The decay curves of the 4G5/2 level exhibit non-exponential behavior for all the pressures and were fitted by the generalized Yokota-Tanimoto model to probe the nature of the energy transfer process. The best fits with S = 6 indicate that the energy transfer between donor and acceptor is of dipole-dipole type. The crystal-field splitting experienced by the Sm3+ ions in the title glass are found to be larger than those found in borate, K-Ba-Al phosphate and tellurite glasses.

  12. Two dielectric relaxation mechanisms observed in lanthanum doped barium strontium titanate glass ceramics

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Ma, Tao; Wang, Xiangrong; Yuan, Zongbao; Zhang, Qian

    2011-04-01

    The dielectric relaxation at temperatures ranging from 100 °C to 550 °C in lanthanum-doped barium strontium titanate glass ceramics has been investigated by measurements of both dielectric temperature curve and complex impedance spectroscopy. The temperature dependence of dielectric properties reveals two regimes. In the first regime, at temperatures lower than 350 °C, the charge carrier contributed to interfacial polarization is conduction electrons. In contrast, in the second regime, at temperatures higher than 350 °C, the dielectric relaxation was attributed to the thermally activated movement of oxygen vacancies. Thus, two relaxation mechanisms could be explained on the basis of defect chemistry and impedance analysis.

  13. Enhanced broadband excited upconversion luminescence in Ho-doped glasses by codoping with bismuth.

    PubMed

    Xu, Beibei; Bai, Gongxun; Wang, Juechen; Guo, Qiangbing; Tan, Dezhi; Chen, Weibo; Liu, Xiaofeng; Zhou, Shifeng; Hao, Jianhua; Qiu, Jianrong

    2014-05-15

    We report enhanced green and red upconversion (UC) luminescence in Ho3+-doped oxyfluoride germanate glass by introducing bismuth near-infrared active centers as sensitizers. The UC excitation bands at 750 and 970 nm show a full width at half-maximum of 20 and 45 nm, respectively. Energy transfer from sensitizers, the excited-state absorption, and phonon-coupled absorption of Ho3+ jointly contribute to the enhanced UC luminescence. Our approach provides an efficient methodology to broaden the excitation bandwidth of UC luminescent materials, which may have the potential for promising application in solar cells. PMID:24978263

  14. Spectroscopic Studies on Eu{sup 3+} Doped Boro-Tellurite Glasses

    SciTech Connect

    Selvaraju, K.; Marimuthu, K. [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram - 624 302 (India)

    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.

  15. Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

    PubMed

    Xu, Tie-Feng; Li, Guang-Po; Nie, Qiu-Hua; Shen, Xiang

    2006-06-01

    Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed. PMID:16458052

  16. Ultrasonic study on some borosilicate glasses doped with different transition metal oxides

    NASA Astrophysics Data System (ADS)

    Marzouk, S. Y.; Gaafar, M. S.

    2007-12-01

    Longitudinal and shear ultrasonic wave velocities were measured in borosilicate glasses doped with different transition metal oxides (TMOs) (where TMO=NiO, V 2O 5, Fe 2O 3, MnO 2, TiO 2, Cr 2O 3, CoO, CuO) using the pulse echo technique. Measurements were carried out at 4 MHz frequency and at room temperature. Elastic moduli and some other physical parameters such as acoustic impedance, softening temperature, Debye temperature, thermal expansion coefficient, and latent heat of melting have been calculated. Results indicated that these parameters depend upon the TMO modifier, i.e., the ionic radius of the transition metal cation. A quantitative analysis has been carried out, in order to obtain more information about the structure of these glasses, based on bond compression model, and the Makishima and Mackenzie model, i.e., the cation-anion bond of each TMO.

  17. The optical properties of trivalent rare earth ions (Er3+) doped borotellurite glass

    NASA Astrophysics Data System (ADS)

    Nurbaisyatul, E. S.; Azman, K.; Azhan, H.; Razali, W. A. W.; Noranizah, A.; Hashim, S.; Alajerami, Y. S. M.

    2014-03-01

    Erbium doped borotellurite glass has been fabricated by using conventional melting method. The density and molar volume have been calculated and analyzed while their optical properties were studied by measuring the optical absorption and luminescence spectra at room temperature. From the XRD results, since the patterns do not exhibit any diffraction line thus it confirms their amorphous nature. It is found that the density of the glass samples increased and the molar volume decreased with respect to Er ions content. Meanwhile, the upconversion emissions centered at 487, 523, 558, 642, 695 and 782 nm have been observed under the 650 nm excitation in the 4 F 9/2 level. Some other results will be analysed and discussed in details.

  18. 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 [Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Edgar, Andy; Varoy, Chris [School of Chemical and Physical Sciences and MacDiarmid Institute, Victoria University of Wellington, Kelburn Parade (New Zealand); Belev, George; Wysokinski, Tomasz [Canadian Light Source Inc., University of Saskatchewan, Saskatoon, SK S7N 0X4 (Canada); Chapman, Dean [Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada)

    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.

  19. Spatially resolved measurement of high doses in microbeam radiation therapy using samarium doped fluorophosphate glasses

    NASA Astrophysics Data System (ADS)

    Okada, Go; Morrell, Brian; Koughia, Cyril; Edgar, Andy; Varoy, Chris; Belev, George; Wysokinski, Tomasz; Chapman, Dean; Kasap, Safa

    2011-09-01

    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 Sm3+ ? Sm2+ valence conversion in Sm3+ 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 ˜5 Gy and saturates at doses exceeding ˜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.

  20. Structural, thermal and optical investigations of Dy3+ ions doped lead containing lithium fluoroborate glasses for simulation of white light

    NASA Astrophysics Data System (ADS)

    Zulfiqar Ali Ahamed, Sd.; Madhukar Reddy, C.; Deva Prasad Raju, B.

    2013-05-01

    Lead containing barium zinc lithium fluoroborate (LBZLFB) glasses doped with different concentrations of trivalent dysprosium ions were synthesized by conventional melt quenching method and characterized through the XRD, DSC, FTIR, FT-Raman, optical absorption, photoluminescence and decay curve analysis. X-ray diffraction studies revealed amorphous nature of the studied glass matrices. The thermal behavior has been reported by recording DSC thermograms. Coexistence of trigonal BO3 and tetrahedral BO4 units was evidenced by IR and Raman spectroscopy. Judd-Ofelt intensity parameters have been evaluated for 1.0 mol% Dy3+ ions doped LBZLFB glass. The measuring branching ratios are reasonably high for transitions 4F9/2 ? 6H15/2 and 6H13/2 suggesting that the emission at 486 and 577 nm, respectively can give rise to lasing action in the visible region. From the visible emission spectra, the yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were estimated. A combination of blue and yellow emissions has emerged in the glasses, which allows the observation of white light when the glasses are excited by the ultraviolet/blue light. These Dy3+ doped glasses are studied for their utility for white light generation under 454 nm excitation and the present LBZLFB glass is more suitable for generation of white light for blue LED chips.

  1. Fluorine-doping concentration and fictive temperature dependence of self-trapped holes in SiO{sub 2} glasses

    SciTech Connect

    Wang, R.P.; Tai, N.; Saito, K.; Ikushima, A.J. [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan and Laser Physics Centre, Research School of Physical Science and Engineering, Australian National University, Canberra ACT 0200 (Australia); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2005-07-15

    Fictive temperature (T{sub f}) and fluorine (F)-doping concentration dependences of self-trapped holes (STHs) in silica glasses created by UV irradiation at low temperatures have been studied by the electron-paramagnetic-resonance method. It was found that the yield of STH decreases with decreasing T{sub f} and increasing F-doping concentration. In combination with infrared spectra measurements, the correlation among T{sub f}, F-doping concentration, Si-O bond length, and Si-O-Si bond angle was elucidated. We conclude that the change in both T{sub f} and F doping can modify the network of SiO{sub 2} glass, leading to the suppression of the formation of STHs.

  2. 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.

  3. Influence of Al\\/Nd ratio on light-emitting properties of Nd-doped glass prepared by sol-gel process

    Microsoft Academic Search

    Qing Xiang; Yan Zhou; Yee Loy Lam; BoonSiew Ooi; YuenChuen Chan; ChanHin Kam

    1999-01-01

    For rare earth doped silica-based glasses derived by sol-gel process, Al was used as a modifier in order to improve the dispersion of the rare earth ion in silica lattices, and thus, make the higher rare earth doped silica glasses without clustering possible. In this research, the influence of the ratio of Al to Nd on the fluorescence intensity and

  4. Leaching of actinide-doped nuclear waste glass in a tuff-dominated system

    SciTech Connect

    Bazan, F.; Rego, J.; Aines, R.D.

    1987-01-01

    A laboratory leaching test has been performed as part of a project to evaluate the suitability of tuff rocks at Yucca Mountain, Nevada, as a site for a high-level nuclear waste repository. Glass samples were placed in water inside tuff vessels, and then the tuff vessels were placed in water inside Teflon containers. Glass-component leach rates and migration through the tuff were measured for samples of the ATM-8 actinide glass, which is a PNL 76-68 based glass doped with low levels of {sup 99}Tc, {sup 237}Np, {sup 238}U, and {sup 239}Pu to simulate wastes. Disc samples of this glass were leached at 90{sup 0}C for 30, 90, and 183 days inside tuff vessels using a natural groundwater (J-13 well-water) as the leachant. At the end of each leaching interval, the J-13 water present inside and outside the rock vessel was analyzed for glass components in solutions. Boron, molybdenum, and technetium appear to migrate through the rock at rates that depend on the porosity of each vessel and the time. The actinide elements were found only in the inner leachate. Normalized elemental mass loss values for boron, molybdenum, and technetium were calculated using concentrations of the inner and outer leachates and assuming a negligible retention on the rock. The maximum normalized release was 2.3 g/m{sup 2} for technetium. Boron, molybdenum, technetium, and neptunium were released linearly with respect to each other, with boron and molybdenum released at about 85% of the technetium rate, and neptunium at 5 to 10% of the technetium rate. Plutonium was found at low levels in the inner leachate but was strongly sorbed on the steel and Teflon supports. Neptunium was sorbed to a lesser extent. 8 refs., 6 figs., 6 tabs.

  5. 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.

  6. Eu3+ ion doped sodium-lead borophosphate glasses for red light emission

    NASA Astrophysics Data System (ADS)

    Kiran, Nallamala

    2014-05-01

    Sodium-lead borophosphate glasses doped with different concentrations of Eu3+ ion are prepared by using the melt quenching technique to study their physical, XRD FTIR and luminescence properties to understand the lasing potentialities of these glasses. The XRD studies confirm the amorphous nature of the glasses. FTIR spectrum indicates the presence of BO3 and PO4 structural units. From the emission spectra, Judd-Ofelt (J-O) intensity parameters have been evaluated from the transition 5D0 ? 7FJ (J = 2 and 4). The evaluated (J-O) intensity parameters have been used to calculate the radiative transition probabilities, luminescence branching ratio and radiative decay times. The intensity ratio (R) value due to 5D0 ? 7F2/5D0 ? 7F1 transition intensity of Eu3+ ions, increase with increasing concentrations suggesting higher asymmetry and covalent bonding character between rare earth ion and oxygen ligands. The chromaticity coordinates were calculated and analyzed with Commission International deI'Eclairage color diagram. The lifetimes of 5D0 metastable state for the samples with different concentrations were also measured and discussed. The predicted and experimental lifetimes for the 5D0 level in sodium lead borophosphate glasses were compared and discussed in detail.

  7. Structural and luminescence studies of Ho3+-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

    NASA Astrophysics Data System (ADS)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y. C.

    2015-06-01

    Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (AR), branching ratios (?R), radiative lifetimes (?R) were calculated and discussed. From the emission spectra emission peak positions (?P), effective bandwidths (??eff) and stimulated emission cross-sections (?P) were calculated for the observed emission transitions,5S2 (5F4?5I8) and 5F5?5I8 in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation.

  8. 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

  9. Praseodymium doped NaYF4 nanocrystals in oxyfluoride glass-ceramics; morphological and spectroscopic studies.

    PubMed

    Dominiak-Dzik, G

    2009-04-01

    The synthesis, morphology, optical properties and excited state dynamics of the Pr-doped NaYF4 nanocrystals in glass-ceramics are presented. The crystalline cubic NaYF4:Pr were synthesized by the controlled heat-treatment of multicomponent oxyfluoride glass based on silica and YF3. A series of the two-hour heat treatments at 620-660 degrees C were carried out yielding visually transparent materials. Above 660 degrees C an opaque material was obtained. The crystalline phase was characterized by the X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The effect of ceramming temperature on the NaYF4:Pr cell parameter (a = 5.470 A for NaYF4 and 5.4899 A, 5.4979 A and 5.5378 A in glass-ceramics) and particle average size (15-40 nm) was observed. Optical characteristics of formed glass-ceramics were favorably affected by the Pr3+ ions in well-defined sites of NaYF4; emission intensities increased and luminescence decay curves become single exponential with the longer corresponding lifetimes. PMID:19437997

  10. Broad-Spectrum Bactericidal Activity of Ag2O-Doped Bioactive Glass

    PubMed Central

    Bellantone, Maria; Williams, Huw D.; Hench, Larry L.

    2002-01-01

    Bioactive glass has found extensive application as an orthopedic and dental graft material and most recently also as a tissue engineering scaffold. Here we report an initial investigation of the in vitro antibacterial properties of AgBG, a novel bioactive glass composition doped with Ag2O. The bacteriostatic and bactericidal properties of this new material and of two other bioactive glass compositions, 45S5 Bioglass and BG, have been studied by using Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus as test microorganisms. Concentrations of AgBG in the range of 0.05 to 0.20 mg of AgBG per ml of culture medium were found to inhibit the growth of these bacteria. Not only was AgBG bacteriostatic, but it also elicited a rapid bactericidal action. A complete bactericidal effect was elicited within the first hours of incubation at AgBG concentrations of 10 mg ml?1. 45S5 Bioglass and BG had no effect on bacterial growth or viability. The antibacterial action of AgBG is attributed exclusively to the leaching of Ag+ ions from the glass matrix. Analytical measurements rule out any contribution to AgBG-mediated bacterial killing by changes in pH or ionic strength or the dissolution of other ionic species from the biomaterials. Our observations of the dissolution profiles of Ag+ from AgBG in the presence and absence of bacteria are consistent with silver accumulation by the bacteria. PMID:12019112

  11. Borate substituted ettringites

    SciTech Connect

    Csetenyi, L.J.; Glasser, F.P. [Univ. of Aberdeen, Old Aberdeen, Scotland (United Kingdom)

    1993-12-31

    The setting of cement is adversely affected by soluble borates. To reduce interference, the extent to which borate can be insolubilized has been investigated. One specific mechanism of insolubilization is by inclusion into ettringite. Ettringite, Ca{sub 6}Al{sub 2}(SO{sub 4}){sub 3}(OH){sub 12}{center_dot}26H{sub 2}O, is a normal and stable constituent of Portland cement. It has an open but non-zeolitic framework. Borate can substitute partially or fully for sulfate. Formation conditions, solubility and stability of borate ettringites, Ca{sub 6}Al{sub 2}(BO{sub 4}){sub 2-4}(OH,O){sub 12}{center_dot}26H{sub 2}O, are characterized using XRD, IR, DTA, and SEM. The potential durability of borate ettringites in a repository environment have been assessed by exposing it to Na-sulfate and Na-carbonate attack at different concentrations. Ion exchange occurs; back substitution of borate by sulfate is incomplete; high carbonate concentrations can, however, decompose borate ettringite. On heat treatment up to 85{degrees}C the crystalline morphology and the OH arrangement of the structure are altered, but the X-ray powder pattern, and hence its structural framework are largely unaffected. It is concluded that ettringite has potential to reduce the solubility of borate.

  12. Hydrophilic\\/hydrophobic conversion of Ni-doped TiO 2 thin films on glass substrates

    Microsoft Academic Search

    Kyu-Seog Hwang; Ju-Hyun Jeong; Jun-Hyung Ahn; Byung-Hoon Kim

    2006-01-01

    Nickel-doped titanium oxide thin films were prepared on soda–lime–silica glass substrates by using a metal naphthenate. Films prefired at 500°C for 10min were finally annealed at 600°C for 30min in air. Contact angle measurement was used for analyzing hydrophilic\\/hydrophobic conversion. NiTiO3, rutile and anatase peaks were obtained for the film after nickel doping. The film containing nickel showed a shift

  13. 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

  14. Transparent Ni2+-doped lithium-alumino-silicate glass-ceramics for broadband near-infrared light source

    NASA Astrophysics Data System (ADS)

    Zhou, Shifeng; Feng, Gaofeng; Wu, Botao; Xu, Shiqing; Qiu, Jianrong

    2007-04-01

    Broadband infrared luminescence centred at around 1300 nm with full-width at half maximum of about 342 nm was observed from transparent Ni2+-doped lithium-alumino-silicate glass-ceramics embedded with ?-eucryptite crystallines. The room temperature fluorescent lifetime was 98 µs. The transparent glass-ceramics may have potential applications in a widely tunable laser and a super-broadband optical amplifier for optical communications.

  15. Investigations on spectroscopic properties of Pr3+ and Nd3+ doped zinc-alumino-sodium-phosphate (ZANP) glasses

    NASA Astrophysics Data System (ADS)

    Brahmachary, K.; Rajesh, D.; Babu, S.; Ratnakaram, Y. C.

    2014-05-01

    Zinc-alumino-sodium-phosphate (ZANP) glasses doped with rare earth metal ions (Nd3+ and Pr3+) with different concentrations (0.5, 1.0, 1.5, 2.0 and 2.5 mol%) were prepared by melt quenching technique. X-ray diffraction, SEM with EDS, Raman spectra, FTIR-spectra, DTA, absorption and luminescence spectra were recorded at room temperature for all the glass matrices and analyzed. X-ray diffraction profiles and SEM images confirmed the amorphous nature of the glass samples. The EDS spectrum of doped and undoped glasses reveals the chemical composition present in them. Structural information of these glass matrices was provided by FTIR and Raman spectra. From DTA analysis, the glass transition temperature (Tg) and crystallization temperature (Tc) were determined. From the absorption spectra, the Judd-Ofelt (J-O) parameters, ?? (? = 2, 4 and 6) and other radiative properties like transition probabilities (AR), radiative lifetimes (?R) and branching ratios (?R) were evaluated. Branching ratios and stimulated emission cross-sections show that 4F3/2 ? 4I11/2 transition of Nd3+ ion and 3P0 ? 3H4 transition of Pr3+ ion of the glasses under investigation have strong emission at 1060 and 490 nm respectively. The results obtained were compared with reports on similar glasses.

  16. Molecular dynamics simulation and crystal-field theory: Predicting the optical spectra and structure of rare-earth doped inorganic glasses

    Microsoft Academic Search

    Guy Cormier

    1993-01-01

    Simulated structural models were developed for two doped inorganic glasses, Na2O-2SiO2-Eu(III) and SiO2-Eu(III). The simulated structure of the base glasses and the local environment of the doped Eu(III) ions were investigated with the help of radial distribution functions, cumulative distribution functions, and bond angle distributions of the various atomic species found in both glasses. A successful validation of the simulated

  17. Engineering of the extraordinary optical transmission of metallic gratings via Er3+-doped tellurite glass

    NASA Astrophysics Data System (ADS)

    Silva, O. B.; Rivera, Victor A. G.; Marega, E.

    2015-03-01

    Although the properties of extraordinary optical transmission (EOT) due surface plasmon polariton (SPP), which are coupled in metallic slits have been widely studied in the last two decades, their influence on the absorption and transmission spectra from their dielectric substrates has not been deserved the same attention. The choice of a good substrate for implementation not just for gratings, but also for other devices, it is extremely important in order to achieve great applications of the EOT. Good candidates to replace the conventional semiconductor based substrates are the rare earth ions (REI) doped glasses. The specific case of Erbium ions and its implementation into glasses for the fabrication of fiber optics, as Erbium doped fiber amplifiers (EDFA). The transmission observed through the plasmonic nanostructures is elucidated considering the following effects: (i) white light absorption by the Er3+ ions, (ii) coupling between the light and the nanostructure via the creation of surface plasmon polariton where the wavelengths with minimums transmission corresponds to the 4I15/2 ? [2H9/2, 4F3/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2] absorption levels the Er3+, which propagates through the slits, and, finally, (iii) the Er3+ transmission intensity and the spectral shape -symmetry depend on the nature of metallic film and the number of slits constituting the arrays, for which the resonant properties are strongly affected. Furthermore, in order to compare the influence of substrate in the transmission properties, we also performed the same measurements on slit arrays fabricated on the BK 7 glass.

  18. Differentiation of human mesenchymal stem cells on niobium-doped fluorapatite glass-ceramics

    PubMed Central

    Kushwaha, Meenakshi; Pan, Xueliang; Holloway, Julie A.; Denry, Isabelle L.

    2011-01-01

    Objectives Our goal was to characterize the response of human mesenchymal stem cells (hMSCs) to a niobium-doped fluorapatite-based glass-ceramic (FAp). Methods The glass was prepared by twice melting at 1525°C for 3h, and cast into cylindrical ingots later sectioned into discs and heat-treated to promote crystallization of fluorapatite submicrometer crystals. Tissue culture polystyrene (TCP) was used as control. The surface of the FAp discs was either left as-heat treated, ground or etched. Initial cell attachment was assessed at 3h. Proliferation and alkaline phosphatase (ALP) expression data was collected at days 1, 4, and 8. Cell morphology was examined using SEM, at days 2 and 4. Mineralization was evaluated by Alizarin Red staining and SEM. Results Initial cell attachment on as heat-treated, etched, or ground surfaces was similar to that of the positive control group (p>0.05). The percentage of area covered by living cells increased significantly on as heat-treated, etched, or ground surfaces between days 1 and 8 (p<0.05). There was no significant difference amongst groups in cell coverage at day 8, compared to TCP control. SEM revealed well spread polygonal cells with numerous filopodia, either attached to the ceramic surface or connected to neighboring cells. ALP expression at day 8 was significantly higher in osteogenic media compared to growth media on both FAp and control. FAp discs stained positively with alizarin red and calcium-rich mineralized granules associated with fibrils were observed by SEM at day 35. Significance hMSCs displayed excellent attachment, proliferation, and differentiation on niobium-doped FAp glass-ceramic. PMID:22078764

  19. Investigations on optical properties of Sm3+ ion doped boro-phosphate glasses

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K.

    2015-06-01

    The Sm3+ doped Boro-phosphate glasses with the chemical composition 60H3BO3+20Li2CO3+10ZnO+(10-x) H6NO4P+xSm2O3 (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach's energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm3+-Sm3+ ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  20. 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

  1. 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

  2. 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.

  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 in silver-doped glasses Jafar Mostafavi Amjad,1 Hamid Reza Khalesifard,1 Sergei Slussarenko,2 Ebrahim Karimi irradiation may develop novel optical properties, as a consequence of the formation of patterns of silver

  4. Spectral luminescence and information characteristics of transparent lead fluoride nano-glass-ceramics doped with erbium ions

    NASA Astrophysics Data System (ADS)

    Aseev, V. A.; Varaksa, Yu. A.; Klement'eva, A. V.; Kolobkova, E. V.; Nikonorov, N. V.; Sinitsyn, G. V.; Khodasevich, M. A.

    2010-05-01

    Spectral luminescence properties of synthesized transparent nano-glass-ceramics doped with erbium ions are studied. It is shown that, as a result of the secondary heat treatment of nano-glass-ceramics, the width of the luminescence spectrum at half maximum increases more than by 15 nm. Luminescence life-time dependences of erbium ions in studied samples are measured, their absorption cross-sections are determined, and their emission cross-sections are calculated by the McCumber method. Spectral and ultimate information characteristics of erbium-doped fiber amplifiers based on synthesized nano-glass-ceramics are numerically simulated. It is shown that, in the unsaturated gain regime, a substantial ripple of the absorption and emission cross-section spectra and shorter lifetime of the metastable level of the erbium ion reduce the pumping radiation power that is required for obtaining the given peak gain, narrow the gain spectra, and lower the transmission capacity of devices based on nano-glass-ceramics compared to the initial glass. Conversely, fiber amplifiers based on calcium fluoride glass-ceramics, for which the lifetime of the metastable level increases with increasing annealing temperature, have an advantage in the transmission capacity over devices based on the primary glass.

  5. Development of large scale production of Nd-doped phosphate glasses for megajoule-scale laser systems

    SciTech Connect

    Ficini, G. [Centre d`Etudes de Limeil-Valenton, Villeneuve, St. Georges (France); Campbell, J.H. [Lawrence Livermore National Lab., CA (United States)

    1996-05-01

    Nd-doped phosphate glasses are the preferred gain medium for high-peak-power lasers used for Inertial Confinement Fusion research because they have excellent energy storage and extraction characteristics. In addition, these glasses can be manufactured defect-free in large sizes and at relatively low cost. To meet the requirements of the future mega-joule size lasers, advanced laser glass manufacturing methods are being developed that would enable laser glass to be continuously produced at the rate of several thousand large (790 x 440 x 44 mm{sup 3}) plates of glass per year. This represents more than a 10 to 100-fold improvement in the scale of the present manufacturing technology.

  6. Spectroscopic and laser properties of Sm³? ions doped lithium fluoroborate glasses for efficient visible lasers.

    PubMed

    Zulfiqar Ali Ahamed, Sd; Madhukar Reddy, C; Deva Prasad Raju, B

    2013-02-15

    The Sm(3+)-doped lead barium zinc lithium fluoroborate (LBZLFB) glasses of composition 20PbO + 5BaO + 5ZnO + 10LiF + (60-x) B(2)O(3) + xSm(2)O(3), (where x=0.1, 0.5, 1.0, 1.5 and 2.0 mol%) have been prepared by conventional melt quenching technique and their structural and spectroscopic behavior were studied and reported. The amorphous nature of these glass samples was confirmed with XRD studies. The FT-IR and FT-Raman spectra reveal that, the glasses contain BO(3), BO(4), non-bridging oxygen and strong OH bonds. The bonding parameters and the oscillator strengths were determined from the absorption spectra. These parameters have been used to obtain the Judd-Ofelt intensity parameters. Using these intensity parameters various radiative and laser properties were predicted. The values of J-O intensity parameters suggested an increase in the degree of symmetry of the local ligand field at Sm(3+) sites. The decay rates for the (4)G(5/2) level of Sm(3+) ions have been measured and are found to be single exponential at lower concentrations (<1.0 mol%) and turn into non-exponential at higher concentrations (?1.0 mol%), due to energy transfer through cross-relaxation. From the emission characteristic parameters of (4)G(5/2) level, it is concluded that the LBZLFB glasses could be useful for photonic devices like visible lasers, fluorescent display devices and optical amplifiers, operated in the visible region. PMID:23261619

  7. Spectroscopic and laser properties of Sm3+ ions doped lithium fluoroborate glasses for efficient visible lasers

    NASA Astrophysics Data System (ADS)

    Zulfiqar Ali Ahamed, Sd.; Madhukar Reddy, C.; Deva Prasad Raju, B.

    2013-02-01

    The Sm3+-doped lead barium zinc lithium fluoroborate (LBZLFB) glasses of composition 20PbO + 5BaO + 5ZnO + 10LiF + (60 - x) B2O3 + xSm2O3, (where x = 0.1, 0.5, 1.0, 1.5 and 2.0 mol%) have been prepared by conventional melt quenching technique and their structural and spectroscopic behavior were studied and reported. The amorphous nature of these glass samples was confirmed with XRD studies. The FT-IR and FT-Raman spectra reveal that, the glasses contain BO3, BO4, non-bridging oxygen and strong OH bonds. The bonding parameters and the oscillator strengths were determined from the absorption spectra. These parameters have been used to obtain the Judd-Ofelt intensity parameters. Using these intensity parameters various radiative and laser properties were predicted. The values of J-O intensity parameters suggested an increase in the degree of symmetry of the local ligand field at Sm3+ sites. The decay rates for the 4G5/2 level of Sm3+ ions have been measured and are found to be single exponential at lower concentrations (<1.0 mol%) and turn into non-exponential at higher concentrations (?1.0 mol%), due to energy transfer through cross-relaxation. From the emission characteristic parameters of 4G5/2 level, it is concluded that the LBZLFB glasses could be useful for photonic devices like visible lasers, fluorescent display devices and optical amplifiers, operated in the visible region.

  8. Structure and vibrational modes of AgI-doped AsSe glasses: Raman scattering and ab initio calculations

    SciTech Connect

    Kostadinova, O. [Foundation for Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, P.O. Box 1414, Patras GR-26504 (Greece); Chrissanthopoulos, A. [Foundation for Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, P.O. Box 1414, Patras GR-26504 (Greece); Department of Chemistry, University of Patras, Patras GR-26504 (Greece); Petkova, T. [Institute of Electrochemistry and Energy Systems (IEES), Bulgarian Academy of Sciences, Sofia (Bulgaria); Petkov, P. [Laboratory of Thin Film Technology, Department of Physics, University of Chemical Technology and Metallurgy, Sofia (Bulgaria); Yannopoulos, S.N., E-mail: sny@iceht.forth.g [Foundation for Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, P.O. Box 1414, Patras GR-26504 (Greece)

    2011-02-15

    We report an investigation of the structure and vibrational modes of (AgI){sub x} (AsSe){sub 100-x}, bulk glasses using Raman spectroscopy and first principles calculations. The short- and medium-range structural order of the glasses was elucidated by analyzing the reduced Raman spectra, recorded at off-resonance conditions. Three distinct local environments were revealed for the AsSe glass including stoichiometric-like and As-rich network sub-structures, and cage-like molecules (As{sub 4}Se{sub n}, n=3, 4) decoupled from the network. To facilitate the interpretation of the Raman spectra ab initio calculations are employed to study the geometric and vibrational properties of As{sub 4}Se{sub n} molecular units that are parts of the glass structure. The incorporation of AgI causes appreciable structural changes into the glass structure. AgI is responsible for the population reduction of molecular units and for the degradation of the As-rich network-like sub-structure via the introduction of As-I terminal bonds. Ab initio calculations of mixed chalcohalide pyramids AsSe{sub m}I{sub 3-m} provided useful information augmenting the interpretation of the Raman spectra. -- Graphical abstract: Raman scattering and ab initio calculations are employed to study the structure of AgI-AsSe superionic glasses. The role of mixed chalcohalide pyramidal units as illustrated in the figure is elucidated. Display Omitted Research highlights: {yields} Doping binary As-Se glasses with AgI cause dramatic changes in glass structure. {yields} Raman scattering and ab initio calculations determine changes in short- and medium-range order. {yields} Three local environments exist in AsSe glass including a network sub-structure and cage-like molecules. {yields} Mixed chalcohalide pyramids AsSe{sub m}I{sub 3-m} dominate the AgI-doped glass structure.

  9. 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.

  10. Comparative toxicology of borates

    Microsoft Academic Search

    Susan A. Hubbard

    1998-01-01

    Inorganic borates, including boric acid, Na, ammonium, K, and Zn borates generally display low acute toxicity orally, dermally,\\u000a and by inhalation. They are either not irritant or mild skin and eye irritants. Exceptions owing to physiochemical properties\\u000a do occur.\\u000a \\u000a Longer-term toxicological studies have been reported mainly on boric acid or borax where the properties are generally similar\\u000a on an equivalent

  11. Effect of heat treatment on structural, thermal and optical properties of Eu3+ doped tellurite glass: Formation of glass-ceramic and ceramics

    NASA Astrophysics Data System (ADS)

    Dwivedi, A.; Joshi, C.; Rai, S. B.

    2015-07-01

    Eu3+ doped tellurite glass has been synthesized through melt quench method and studied in details at room temperature. The heat treatments to the glass sample convert it into glass-ceramic and ceramic which could be verified structurally by TEM, SEM, XRD measurements. The effect of this on the optical properties of the sample has been studied by UV-Vis-NIR, FTIR, and PL measurements. The optical band gap (Eopt) has been found to increase from 3.82 to 4.04 eV as the sample changes to ceramic from glass. This material thus can also be used as tunable wide band gap (WBG) material whose band gap can be tuned by selective heat treatment of the glass sample. PL measurements show that the emission intensity of Eu3+ decreases as we go from glass to glass-ceramic and then ceramic. The decrease in emission intensity in case of ceramic is well supported by lifetime measurements. The excitation and downconversion (DC) emission mechanism is illustrated by energy level diagram.

  12. Eu3+ doped 1La2O3:2WO3:1B2O3 glass and glass-ceramic

    NASA Astrophysics Data System (ADS)

    Aleksandrov, L.; Iordanova, R.; Dimitriev, Y.; Georgiev, N.; Komatsu, T.

    2014-06-01

    In WO3-La2O3-B2O3 system, glasses were obtained in the region between 20 and 30 mol% La2O3. A liquid-phase separation region was observed near the WO3-B2O3 side. A glass with nominal composition 50WO3:25L2O3:25B2O3 doped with Eu2O3 was synthesized by melt quenching method. The obtained glass was characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), UV-vis, infrared spectroscopy (IR) and photoluminescence spectroscopy (PL). According to the DTA data, Eu3+ ions decrease the glass transition temperature from 621 °C to 574 °C and crystallization temperature from 690 °C to 677 °C. Structural model for the glass network was suggested on the base of IR and UV-vis spectral investigations. It was established that WO4 and WO6 structural units (620-960 cm-1) and BO3 and BO4 polyhedra (1050-1380 cm-1) build up the glass network. During vitrification partial transformation of WO4 to WO6 and BO3 to BO4 was proved. The quenched glass is transparent in the visible region and exhibits typical absorption bands of Eu3+ ions due to the 4f transitions 5D0 ? 7Fj (j = 0-4). A glass-ceramic consisting of LaBWO6:Eu3+ nanocrystals with enhanced photoluminescence emissions is synthesized. The intensity of emission increases drastically in the glass-crystalline sample compared with the glass and polycrystalline sample.

  13. 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.

  14. Laser-induced dendritic microstructures on the surface of Ag{sup +}-doped glass

    SciTech Connect

    Nahal, A.; Mostafavi-Amjad, J.; Ghods, A.; Khajehpour, M. R. H.; Reihani, S. N. S.; Kolahchi, M. R. [School of Physics, University of Tehran, Kargar Shomali Avenue, 14399-55961, Tehran (Iran, Islamic Republic of); Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of)

    2006-09-01

    Fractal dendritic silver microstructures are observed on the surface of the Ag{sup +}-doped glasses as a result of a photothermal interaction with a focused multiline cw high-power (P{sub max}=8 W) Ag{sup +} laser beam. It is found that evolution of the structures depends on the exposure time and also on the concentration of the silver ions in the sample. The fractal dimension of the generated dendritic microstructures increases with the exposure time. Instability of the contact line of the molten silver flow toward the periphery of the interaction area is discussed as a result of the temperature gradient, due to the Gaussian intensity distribution across the laser beam.

  15. Pr3+-doped fluoro-oxide lithium glass as scintillator for nuclear fusion diagnostics.

    PubMed

    Arikawa, Yasunobu; Yamanoi, Kohei; Nakazato, Tomoharu; Estacio, Elmer Surat; Shimizu, Toshihiko; Sarukura, Nobuhiko; Nakai, Mitsuo; Norimatsu, Takayoshi; Azechi, Hiroshi; Murata, Takahiro; Fujino, Shigeru; Yoshida, Hideki; Kamada, Kei; Usuki, Yoshiyuki; Suyama, Toshihisa; Yoshikawa, Akira; Sato, Nakahiro; Kan, Hirofumi

    2009-11-01

    Experimental results are presented on the neutron scintillating properties of a custom-designed Pr3+ (praseodymium)-doped lithium (Li) glass. Luminescence was observed at 278 nm wavelength, originating from the 5d-4f transition. Time-resolved measurements yielded about 20 ns decay times for ultraviolet and x-ray excitation while much faster decay times of about 6 ns were observed for alpha particle and neutron excitation. Actual time-of-flight data in laser fusion experiments at the GEKKO XII facility of the Institute of Laser Engineering, Osaka University reveal that it can clearly discriminate fusion neutrons from the much stronger x-rays signals. This material can promise improved accuracy in future scattered neutron diagnostics. PMID:19947728

  16. Optical limiting and excited-state absorption in fullerene solutions and doped glasses

    NASA Astrophysics Data System (ADS)

    McBranch, Duncan W.; Smilowitz, Laura B.; Klimov, Victor I.; Koskelo, Aaron C.; Robinson, Jeanne M.; Mattes, Benjamin R.; Hummelen, Jan C.; Wudl, Fred; Withers, James C.; Borrelli, Nicholas F.

    1995-12-01

    We report the ground-state and excited-state optical absorption spectra in the visible and near infrared for several substituted fullerenes and higher fullerenes in toluene solutions. Based on these measurements, broadband predictions of the optical limiting performance of these molecules can be deduced. These predictions are then tested in the wavelength range from 532 nm to 700 nm in intensity-dependent transmission measurements. We observe optical limiting in all fullerenes measured; higher fullerenes show the greatest potential for limiting in the near infrared (650 - 1000 nm), while substituted C60 shows optimal limiting in the visible (450 - 700 nm). We observe dramatically reduced limiting for solid forms of C60 (thin films and C60-doped porous glasses), indicating that efficient optical limiting in fullerenes requires true molecular solutions.

  17. Luminescence and long-lasting afterglow in Mn 2+ and Eu 3+ co-doped ZnO–GeO 2 glasses and glass ceramics prepared by sol–gel method

    Microsoft Academic Search

    Tomoe Sanada; Hisakazu Seto; Yusuke Morimoto; Kazuhiro Yamamoto; Noriyuki Wada; Kazuo Kojima

    2010-01-01

    To develop new fluorescent and afterglow materials, Mn2+ and Eu3+ co-doped ZnO–GeO2 glasses and glass ceramics were prepared by a sol–gel method and their optical properties were investigated by measuring\\u000a luminescence, excitation and afterglow spectra, and luminescence quantum yield (QY). Under UV irradiation at 254 nm, some\\u000a glasses and all of the glass ceramics showed green luminescence peaking at 534 nm due

  18. Structure and luminescence spectra of lutetium and yttrium borates synthesized from ammonium nitrate melt

    Microsoft Academic Search

    Nikolay V. Klassen; Semion Z. Shmurak; Ivan M. Shmyt’ko; Galina K. Strukova; Stephen E. Derenzo; Marvin J. Weber

    2005-01-01

    Lutetium and yttrium borates doped with europium, terbium, gadolinium, etc. have been synthesized by dissolving initial oxides and nitrates in ammonium nitrate melt and thermal decomposition of the solvent. Annealings in the range of 500–1100°C modified the dimensions of the grains from 2 to 3nm to more than 100nm. Significant dependence of the structure of lutetium borate on slight doping

  19. Third-order optical nonlinearity at 800 and 1300 nm in bismuthate glasses doped with silver nanoparticles.

    PubMed

    Chen, Feifei; Cheng, Junwen; Dai, Shixun; Xu, Zhe; Ji, Wei; Tan, Ruiqin; Zhang, Qinyuan

    2014-06-01

    Large and ultrafast third-order optical nonlinearities in Ag-doped bismuthate glasses which are prepared by incorporating Ag ions into bismuthate glasses to form Ag nanoparticles through a consecutive melting-quenching-annealing technique are reported. Due to the high refractive index of bismuthate glass, surface plasmon resonance (SPR) of Ag nanoparticles is extendable to 1400 nm, resulting in a higher nonlinear refractive index than bismuthate glass. Femtosecond Z-scans show that the nonlinear refractive index, as high as 9.4 × 10(-17) and 5.6 × 10(-18) m(2) W(-1) at 800 and 1300 nm, respectively, can be achieved by selecting an optimized concentration of Ag nano-sized particles. And two-photon absorption at 800 nm is suppressed due to a blue shift in the band-gap of Ag-doped bismuthate glasses, as compared to pristine bismuthate glasses. Optical Kerr shutter technique reveals that these nonlinearities have a relaxation time of < 1 ps. PMID:24921537

  20. 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.

  1. Charge carrier transport in molecularly doped polycarbonate as a test case for the dipolar glass model

    NASA Astrophysics Data System (ADS)

    Novikov, S. V.; Tyutnev, A. P.

    2013-03-01

    We present the results of Monte Carlo simulations of the charge carrier transport in a disordered molecular system containing spatial and energetic disorders using the dipolar glass model. Model parameters of the material were chosen to fit a typical polar organic photoconductor polycarbonate doped with 30% of aromatic hydrazone, whose transport properties are well documented in literature. Simulated carrier mobility demonstrates a usual Poole-Frenkel field dependence and its slope is very close to the experimental value without using any adjustable parameter. At room temperature transients are universal with respect to the electric field and transport layer thickness. At the same time, carrier mobility does not depend on the layer thickness and transients develop a well-defined plateau where the current does not depend on time, thus demonstrating a non-dispersive transport regime. Tails of the transients decay as power law with the exponent close to -2. This particular feature indicates that transients are close to the boundary between dispersive and non-dispersive transport regimes. Shapes of the simulated transients are in very good agreement with the experimental ones. In summary, we provide a first verification of a self-consistency of the dipolar glass transport model, where major transport parameters, extracted from the experimental transport data, are then used in the transport simulation, and the resulting mobility field dependence and transients are in very good agreement with the initial experimental data.

  2. Investigation of 1.3 ?m emission in Nd 3+-doped bismuth-based oxide glasses

    NASA Astrophysics Data System (ADS)

    Nie, Qiuhua; Li, Xujie; Dai, Shixun; Xu, Tiefeng; Chen, Yanfei; Zhang, Xianghua

    2007-11-01

    Nd 2O 3-doped 43Bi 2O 3- xB 2O 3-(57- x)SiO 2-1.0Nd 2O 3 ( x=57, 47, 39, 28.5, 19.5, 10, 0 mol%) bismuth glasses were prepared by the conventional melt-quenching method, and the Nd 3+: 4F 3/2? 4I 13/2 fluorescence properties had been studied in an oxide system Bi 2O 3-B 2O 3-SiO 2. The Judd-Ofelt analysis for Nd 3+ ions in bismuth boron silicate glasses was also performed on the basis of absorption spectrum, and the transition probabilities, excited-state lifetimes, the fluorescence branching ratios, quantum efficiency and the stimulated emission cross-sections of 4F 3/2? 4I 13/2 transition were calculated and discussed. The stimulated emission cross-sections of 1.3 ?m were quite large due to a large refractive index of the host. Although the effective bandwidths decreased with increasing SiO 2 content, quantum efficiencies and stimulated emission cross-sections enhanced largely with increasing SiO 2 content.

  3. Near-infrared emission and energy transfer in tellurite glasses co-doped with erbium and thulium ions

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    In the paper optical properties of 40TeO2 - 20GeO2 - 30(PbO - PbF2)- 10(BaO - Nb2O5 - LaF3) glass system co-doped with Er3+/Tm3+ ions were investigated. The maximum of phonon energy at 790cm-1 in fabricated tellurite glass which was determined by FTIR measurements. Optimisation of glass composition led to the emission at 1820 nm which was observed in results of energy transfer (ET) between Er3+and Tm3+ions under the optical exciting at 976 nm. In order to determine the optimal conditions of ET between exited energy levels of co-doped RE ionsthe dependence of the near-infrared emission upon the thulium ions concentration was studied. In result of that broadband emission in the range from1500 to 1900 nm was achieved owing to the superposition of electronic transition in Er3+ (4I13/2 ? 4I15/2) and Tm3+ (3F4 ? 3H6) ions.The highest efficiency of energy transfer was obtained in glass co-doped with 0.2Er2O3/0.3 Tm2O3.

  4. Fluorescence mechanisms of Tm3+- and Yb3+/Tm3+ doped AlF3-based fluoride glass

    NASA Astrophysics Data System (ADS)

    Zhang, Long; Zhang, Jun-jie; Hu, He-fang; Lin, Feng-ying

    2001-01-01

    A complete set of spectroscopic parameters, including Judd-Ofelt parameters, radiative transition probabilities, radiative lifetime, branching ratios and integrated absorption cross section, have been calculated for Tm3+- doped fluoroaluminate (AYF) glass, based on the measured absorption spectra. The mechanism of Tm3+?Tm3+ and Yb3+??Tm3+ energy transfers and fluorescence properties have been investigated in both Tm3+ single-doped and Yb3+/Tm3+ double-doped AYF glasses. The cross-relaxation process, 3F4+3H6?23H4, is proved, which makes the optimum Tm3+ concentration of 1.77µm fluorescence (3H4? 3H6) much higher than 1.45µm fluorescence (3F4? 3H4) in Tm3+:AYF glasses. In Yb3+/Tm3+:AYF glasses, a stronger concentration quenching is found for the 476nm emission than that for the 797nm emission and is discussed under the 970nm-excitation.

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

    SciTech Connect

    Gomes, Laercio [Instituto de Pesquisas Energeticas e Nucleares, Centro de Lasers e Aplicacoes, P.O. Box 11049, Sao Paulo, SP 05422-970 (Brazil); Lousteau, Joris; Milanese, Daniel; Scarpignato, Gerardo C. [PhotonLab, Dipartimento di Scienza dei Materiali ed Ingegneria Chimica, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Jackson, Stuart D. [Institute of Photonics and Optical Science, School of Physics, University of Sydney, Camperdown, 2006 (Australia)

    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.

  6. Nd3+ and Yb3+ doped phosphate glass waveguides fabricated using electric field assisted Ag+ diffusion

    SciTech Connect

    Patel, F.D.; Honea, E.C.; Krol, D.; Payne, S.A.; Hayden, J.S.

    1997-12-17

    Solid-state waveguide lasers offer several attractive features that may make high efficiency and effective thermal management possible. Due to the ability to confine pump light to high intensity over distances much longer than the Rayleigh range, as well as maintaining good overlap between the pump and Iasing modes over the entire guiding region, effcient operation with high slope efficiency should be possible, even for quasi-three level laser systems. Since the waveguide region is typically only a few microns of thickness, heat can be extracted efficiently from the structure. The effects of heating are of less significance than in bulk solid-state lasers because mode confinement is maintained by an index of refraction difference, usually much larger than tnat induced by dn/dT or stress-optic effects. Rare earth doped waveguide laser action has been reported in numerous papers [14]. The processes for fabricating waveguides include film deposition methods such as epitaxial growth, RF sputtering, and most recently, thermal bonding of precision finished crystals [5]. In addition, ion implantation, ion exchange in a molten salt and electric field assisted solid film diffusion [6] have been utilized. The ion exchange method remains the simplest, particularly for many common laser glasses that already have mobile ions, and has received considerable attention in recent years. An excellent review is found in reference [7]. Our work has focused on developing process conditions for the fabrication of waveguides in phosphate laser glasses using solid silver film diffusion. These processes are important in determining the overall structure and properties of the guiding region, such as propagation loss, modal profile, and modal overlap between the pump and laser wavelengths. Phosphate laser glass was chosen as the solid state laser medium due to the useful spectroscopic properties of rare earth ions in these materials, as well as the range of material properties and compositions possible.

  7. 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.

  8. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

  9. Effect of absorption recovery in bismuth-doped silica glass at 1450 nm on soliton grouping in fiber laser.

    PubMed

    Gumenyuk, R; Melkumov, M A; Khopin, V F; Dianov, E M; Okhotnikov, O G

    2014-01-01

    Saturable absorption in bismuth-doped glasses was found to have a noticeable influence on soliton interaction and group formation. This phenomenon, observed in 1450 nm mode-locked bismuth-doped fiber laser, shows the distinct feature of the multiple pulse regime, which appears as a stationary pulse group whose length can be spread over the whole cavity length by variation of the pump power and polarization. Pulse positioning within the ensemble depends on the saturation fluence and the relatively fast recovery dynamics of bismuth fiber. PMID:25391808

  10. The double role played by the Gd 2O 3 in the gadolinium–aluminum–borate–bismuthate quaternary glass forming tendency. GdBO 3 crystalline phase

    Microsoft Academic Search

    S. Rada; M. Culea; M. Rada; P. Pascuta; V. Maties; E. Culea

    2009-01-01

    Glasses and glass–ceramics in the xGd2O3·(100?x)[2Bi2O3·B2O3·Al2O3] system with x=0, 1, 5, 10, 15, 20, 25, 30, 35, 50mol% Gd2O3 have been prepared by the melt quenching method. The changes of the IR spectral features suggest that the formation of [BO4] tetrahedra is reduced because the modified [BO3] units containing one or more B–O–Gd bonds are unable to accept the fourth

  11. Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques

    Microsoft Academic Search

    M. S. Gaafar; N. S. Abd El-Aal; O. W. Gerges; G. El-Amir

    2009-01-01

    Glasses in the system (1?x) [29Na2O? 4Al2O3? 67B2O3]?xZnO (0?x?35mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4MHz at room temperature. The

  12. Lab Procedure Sodium Borate Crystals

    E-print Network

    Pike, Robert D.

    Lab Procedure Sodium Borate Crystals Materials: Plastic cup, marked for 50 mL Styrofoam cup 50 m a styrofoam cup, Sodium Borate solution. 2. Place 2 teaspoons of sodium borate in the Styrofoam cup. 3. Place hydrate Plastic cup, marked for 50 mL Styrofoam cup 50 mL of deionized water Plastic spoon String

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

    SciTech Connect

    Jana, Sunirmal, E-mail: sjana@cgcri.res.in [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India)] [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India); Vuk, Angela Surca [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia)] [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Mallick, Aparajita [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India)] [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India); Orel, Boris [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia)] [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Biswas, Prasanta Kumar [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India)] [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research, CSIR, India), 196 Raja S. C. Mullick Road, Kolkata 700032 (India)

    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.

  14. Comparative spectroscopy of (ErF 3)(PbF 2) alloys and Er 3+-doped oxyfluoride glass-ceramics

    Microsoft Academic Search

    V. K. Tikhomirov; V. D. Rodríguez; J. Méndez-Ramos; P. Núñez; A. B. Seddon

    2004-01-01

    We have prepared polycrystalline alloys x(ErF3):(100?x)(PbF2), x=1,10. A comparison of their low temperature absorption and emission spectra with the respective spectra of transparent oxyfluoride glass-ceramics, 32(SiO2)9(AlO1.5)31.5(CdF2)18.5(PbF2)5.5(ZnF2):3.5(ErF3)mol%, indicates that the nano-crystalline phase in this glass-ceramic is Er3+-doped PbF2.

  15. Persistent spectral hole burning of sol-gel-derived Eu3+-doped SiO2 glass

    Microsoft Academic Search

    Masayuki Nogami; Tomokatsu Hayakawa

    1997-01-01

    Persistent spectral hole burning (PSHB) was observed at temperatures higher than 77 K in the sol-gel-derived Eu3+-doped SiO2 glasses. 1Eu2O3.99SiO2 (mole ratio) glass was prepared by heating gel synthesized from metal alkoxides at 400 to 1000 °C. The hole was burned in the 7F0-->5D0 line of Eu3+ ions by means of a Rhodamine 6G dye laser at 77 K and

  16. Upconversion in Er3+-doped Bi2O3-Li2O-BaO-PbO tertiary glass.

    PubMed

    Tripathi, Garima; Rai, Vineet Kumar; Rai, D K; Rai, S B

    2007-04-01

    Radiative properties of Er3+-doped tertiary bismuth glass has been analyzed by the Judd-Ofelt theory. NIR to visible upconversion in the Er3+-doped glass has been reported. The mechanism for the upconversion is explained on the basis of quadratic dependence on excitation power and on the energy-matching scheme. Energy transfer is noted as the dominant process including the long-lived 4I11/2 level as the intermediate state for the green and red upconversion emissions. The effect of temperature on the fluorescence intensity of the two bands due to 2H11/2-->4I15/2 and 4S3/2-->4I15/2 transitions as well as on the transitions due to Stark components of the 4S3/2 level have been monitored and it is concluded that their intensity ratio may serve as better temperature sensing device. PMID:16920009

  17. Nonlinear optical properties of CdS1-xSex crystallites-doped glass in femtosecond time-scale.

    NASA Astrophysics Data System (ADS)

    Ma, Seongmin

    2005-04-01

    We report the nonlinear optical properties of CdS1-xSex crystallites doped in glass measured with a 150 fs Ti:Sappire laser at 775 nm wavelength. The nonlinear absorption and nonlinear refraction coefficients were measured to be 1x10-20 m^2/W and 7x10-15^ W/m , respectively, by using a single beam Z-scan nonlinear spectroscopy technique. Experimental data is theoretically fitted and discussed. The dominant physical origin of the optical nonlinearity of the material is two-photon resonant electronic process. The large nonlinearity indicates CdS1-xSex crystallite doped glass is an excellent candidate for photonic applications, such as defense for homeland security, battlefield enhancements, optical switching, and pulse shaping.

  18. [Optical limiting response in Er3+-doped TeO2-Nb2O5-ZnO glass].

    PubMed

    Li, Yu-qiong; Sun, Zhen-rong; Kang, Hai-feng; Yuan, Yi-zhong; Wang, Zu-geng

    2007-01-01

    Nonlinear optical properties of Er+ doped heavy metal telluride glass were studied by picosecond laser pulses. The optical limiting response was measured by a transmission technique, and the reverse saturable absorption (RSA) by a Z-scan technique. When the incident power reached the threshold, the tranmitted power did not grow rapidly with the incident power as before, but remained almost constant. It means that the Er3+ -doped glass possesses an optical limiting effect. The experimental results show that the excited absorption is responsible for the measured RSA, resulting in optical limiting response. The measured data can be well simulated by a rate equation model to obtain the absorption cross sections of the excited state. PMID:17390635

  19. Optical parameters and upconversion fluorescence in Tm3+/Yb3+-doped alkali-barium-bismuth-tellurite glasses.

    PubMed

    Lin, Hai; Liu, Ke; Lin, Lin; Hou, Yanyan; Yang, Dianlai; Ma, Tiecheng; Pun, Edwin Yun Bun; An, Qingda; Yu, Jiayou; Tanabe, Setsuhisa

    2006-11-01

    Tm(3+)/Yb(3+)-doped alkali-barium-bismuth-tellurite (LKBBT) glasses have been fabricated and characterized. Density, refractive index, optical absorption, absorption and emission cross-sections of Yb(3+), Judd-Ofelt parameters and spontaneous transition probabilities of Tm(3+) have been measured and calculated, respectively. Intense blue three-photon upconversion fluorescence and near-infrared two-photon upconversion fluorescence were investigated under the excitation of a 980 nm diode laser at room temperature. Wide infrared transmission window, high refractive index and strong blue three-photon upconversion emission of Tm(3+) indicate that Tm(3+)/Yb(3+) co-doped LKBBT glasses are promising upconversion optical and laser materials. PMID:16527521

  20. Nonlinear optical properties of CdS1-xSex crystallites-doped glass in femtosecond time-scale

    Microsoft Academic Search

    Seongmin Ma

    2005-01-01

    We report the nonlinear optical properties of CdS1-xSex crystallites doped in glass measured with a 150 fs Ti:Sappire laser at 775 nm wavelength. The nonlinear absorption and nonlinear refraction coefficients were measured to be 1x10-20 m^2\\/W and 7x10-15^ W\\/m , respectively, by using a single beam Z-scan nonlinear spectroscopy technique. Experimental data is theoretically fitted and discussed. The dominant physical