Tellurite glasses: Part 2. Anelastic, phase separation, Debye temperature and thermal properties

The goal of the present review is to collect and analyze the dependence of the longitudinal ultrasonic attenuation with different frequencies and temperature (below room temperature) and the elastic moduli at room temperature for tellurite glasses containing different modifiers in the binary and ternary forms. The quantitative analysis of the experimental acoustic activation energy has been discussed in terms of the number of loss centers (number of oxygen atoms that vibrate in the double-well potential). Also, the correlations between the acoustic activation energy at low temperature and both bulk modulus at room temperature and mean cation–anion stretching force constant have been collected. The effect of radiation and the presence of nonbridging oxygen atoms (NBO) on the ultrasonic attenuation and internal friction have been collected. Secondly, the phase separation test by using the nondestructive elastic moduli have been collected for these new noncrystalline solids. Thirdly, the acoustic and optical Debye temperature data for tellurite glasses have been collected from the measurements of ultrasonic velocities (both longitudinal and shear waves) and from the theoretical calculations of the IR spectra of these amorphous solids. Also, the effect of γ-radiation on the values of acoustic Debye temperature has been collected. Fourthly, the thermal properties: glass transformation temperature T g, glass crystallization temperature T c and glass melting temperature T m and thermal expansion coefficient α th were collected. The values of glass transformation and crystallization activation energies according to different models have been collected. The correlations between the thermal properties ( T g) with the average crosslink density and average stretching force constant have been collected. While the thermal expansion coefficient has been collected and discussed vibrationally by correlating it with mean long wavelength acoustic mode Gruneisen parameter γ.