Investigation of Acoustical Parameters in Ternary B2O3 ? MnO2 ?Al2O3 GLASSES

Glass samples of composition 60B2O3- (40-x) MnO2-xAl2O3 (where x=0, 5, 10, 15 and 20 mol %) were synthesized by melt quench technique. Longitudinal and shear velocities have been measured at 5 MHz frequency by Pulse - Echo Overlap method. The density of the glasses has also been determined. The density increases while their molar volume values decreases with the increase of Al2O3 concentration. The amorphous nature of the glass samples were checked by XRD technique. Elastic moduli such as longitudinal, bulk, shear and Youngs moduli, Poissons ratio, acoustic impedance, microhardness and Debye temperature were calculated from the measured data. The variations of the above parameters with change in composition have been discussed in terms of structural changes in the glass network.