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Temperature and wavelength dependence of the thermo-optical properties of tellurite and chalcogenide glasses

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The aim of the present work is to attempt to make a number of different glasses, based on tellurite as the principal former, which contain substantial quantities of zinc oxide up to 40 mol % ZnO. To study the longitudinal elastic properties, measurements have been made of the velocity of the longitudinal ultrasonic waves propagated through the prepared glasses. The results indicate that the longitudinal elastic constants depend strongly upon the composition of the prepared glasses. A detailed qualitative interpretation of the increase in the modulus is made. Information about the structure of the glass can be deduced after calculating the number of network bonds per unit volume and the crosslink density. The role of the halogen inside the glass network is discussed.

A series of binary tellurite-phosphate glasses in the form [TeO2]0.81[P2O5]0.19 doped with different rare-earth oxides were prepared. The rare-earth oxides were: La2O3, CeO2, Pr2O3, Nd2O3, Sm2O3, and Yb2O3. The optical absorption coefficient and infrared spectra were measured in the ranges 200–900 nm and 200–1000 cm−1, respectively. It is found that the fundamental absorption edge depends upon the kind of the dopant cation. The infrared spectra of these doped glasses indicate that the rare-earth oxides are connected to the chains of TeO4.

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Theoretical analysis of room temperature bulk modulus and low-temperature ultrasonic attenuation coefficient in the glass system (1-x)TeO2-xV2O5, x = 20, 25, 30, 35, 40 mol % was achieved. The bond compression (BC) and Makishima-Mackenzie (MM) models were used to interpret room-temperature bulk modulus K. The main parameters used were: average cross-link density, number of network bonds per unit volume, and average atomic ring size (). Analyses of low-temperature (300 − 150 K) ultrasonic attenuation (α) at 2, 4, 5, and 6 MHz were achieved by calculating: potential energy, centers of energy loss, elongation, and contraction of the two-well potential. Also, the deformation potential is found to be sensitive to the variations of the modifier content. The analysis revealed a sensitive effect of variation of modifier contents for elongation or contraction of the dual-well potential. The number of centers of energy loss is related to the elastic moduli as a function of the modifier content. Correlation between room temperature bulk modulus and ultrasonic attenuation coefficient has been achieved.