Article

Thermal properties of multicomponent tellurite glass

Journal of Materials Science (Impact Factor: 2.31). 04/2008; 43(15):5131-5138. DOI: 10.1007/s10853-008-2737-4

ABSTRACT Quaternary tellurite glass systems of the form 80TeO2–5TiO2–(15−x)WO3−xAnOm where AnOm is Nb2O5, Nd2O3, and Er2O3, x=0.01, 1, 3, and 5mol% for Nb2O5 and x=0.01, 0.1, 1, 3, 5, and 7mol% for Nd2O3 and Er2O3, have been prepared by the melt quenching. Density and molar volumes have been measured and calculated for every glass system.
The thermal behavior of the glass series was studied by using the differential thermal analysis DSC. Glass transition temperature
T
g, crystallization temperature T
c, and the onset of crystallization temperature T

x
were determined. The glass stability against crystallization S (≈100°C) and glass-forming tendency K
g (≈0.3) have been calculated. Specific heat capacity C
p (≥1.4J/g°C) was measured from room temperature and above the T
g for every composition in each glass series. Quantitative analysis of the above thermal properties of these new tellurite
glass with the structure parameters like average cross-link density
$ \ifmmode\expandafter\bar\else\expandafter\=\fi{n}_{{\text{c}}} $ \ifmmode\expandafter\bar\else\expandafter\=\fi{n}_{{\text{c}}} (≥2.4), number of bonds per unit volume n
b (≥8×1028cm−3), and the average stretching force constant (F) have been studied for every glass composition.

Full-text

Available from: R. El-Mallawany, Jun 15, 2015
2 Followers
 · 
267 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Er3+-doped tellurite glasses with molar compositions of xEr2O3-20ZnO-(80 − 𝑥)TeO2 (𝑥 = 0, 1, 2, 3, and 4 mole%) (EZT) have been successfully synthesized by the melt-quenching method. Density and molar volume have been measured. UV-VIS absorption spectra in the wavelength range of 400–800nm at room temperature has been measured. The band gap for every composition has been calculated. Photoluminescence spectroscopy in the wavelength range of 400–650 nm and at room temperature has been evaluated.
    Advances in Materials Science and Engineering 01/2015; 2015(Article ID 628954):5. DOI:10.1155/2015/628954 · 0.90 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: New ternary zinc oxyfluorotellurite (ZOFT) with the composition (ZnO)𝑥-(AlF3)𝑦-(TeO2)𝑧, where 5 ≤ 𝑥 < 35; 5 ≤ 𝑦 ≤ 25; 60 ≤ 𝑧 ≤ 70, has been successfully prepared by the conventional rapid melt quenching technique. Density, molar volume, and glass transition temperature have been assessed for each ZOFT glass sample. The longitudinal and transverse ultrasonic waves propagated in each glass sample weremeasured using aMBS8020 ultrasonic data acquisition system at 5MHz frequency and room temperature. The longitudinal modulus (𝐿), shear modulus (𝐺), Young’s modulus (𝐸), bulk modulus (𝐾), and Poisson’s ratio (𝜎) are assessed from both velocity data and their respective density. The compositional dependence of the ultrasonic velocities and related parameters are discussed to understand the rigidity and compactness of the glass system studied.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tellurite glasses (TeO2–ZnO–La2O3) doped with Er3+, Er3+/Ce3+ and Er3+/Ce3+/Yb3+ have been prepared using the melt-quenching technique, and the absorption spectra, fluorescence and up-conversion emission spectra together with the differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns were measured to evaluate the effects of Ce3+ and Yb3+ introduction on the 1.53 µm band spectroscopic properties of Er3+, thermal stability and structural nature of glass hosts. The Judd–Ofelt intensity parameters (t=2,4,6), spontaneous emission probabilities, radiative lifetimes and branching ratios of several Er3+ transitions were calculated from the measured absorption spectra based on the Judd–Ofelt theory. The co-doping with Ce3+ was effective on the suppression of up-conversion emission of Er3+ owing to the phonon-assisted energy transfer: Er3+:4I11/2+Ce3+:2F5/2→Er3+:4I13/2+Ce3+:2F7/2, while the co-doping with Yb3+ had the effect of obviously increasing the Er3+ population at 4I11/2 level via the resonant energy transfer: Yb3+:2F5/2+Er3+:4I15/2→Yb3+:2F7/2+Er3+:4I11/2, both of which contributed the effective enhancement of 1.53 µm fluorescence emission. The quantitative studies were carried out to elucidate the energy transfer mechanism by calculating the microscopic parameters and phonon contribution ratios. The glass transition temperature ( ), crystallization onset temperature ( ) and the difference , which characterize the thermal stability of glass host, increased with the Ce3+ and Yb3+ co-doping and for all glass samples the value of is larger than 145 °C. The glass structural nature was demonstrated from the measured XRD patterns with no sharp diffraction peaks. The results of the present work indicated that the prepared Er3+/Ce3+/Yb3+ co-doped tellurite glass is a potential material for developing broad-band and high-gain optical amplifiers and other optical devices.
    Journal of Quantitative Spectroscopy and Radiative Transfer 08/2015; 161. DOI:10.1016/j.jqsrt.2015.03.028 · 2.29 Impact Factor