Effect of Al2O3 addition on the acoustical properties of lithium borate glasses

The effect of addition of Al2O3 to lithium-borate base glass in the place of both lithium and boron has been studied through the acoustical properties of the glasses. The ultrasonic velocity and attenuation for various compositions of Al2O3-containing lithium-borate glasses were measured at 5MHz at room temperature (303K). The elastic moduli, Debye temperature, Poisson's ratio and other acoustical parameters were obtained from the experimental data. The structural changes in the glass network are discussed in terms of the formation of non-bridging oxygen (NBO) with addition of Al2O3 to the base glass. Further, the nature of variation of Debye temperature [in both acoustical and optical (IR)] is used to explain the effect of addition of Al2O3 to the lithium-borate base glass. The relation between the acoustical and optical Debye temperatures is also discussed.