Elastic properties of binary AO3-P2O5 and ternary Na2O-AO3-P2O5 (A-Mo or W) glasses

The elastic properties of several compositions of binary AO3-P2O5 and ternary Na2O-AO3-P2O5 (A-Mo or W) glasses have been studied using ultrasonic measurements. The trends in the variations in the moduli as a function of composition have been examined. The moduli of the binary glasses exhibit opposite trends. In the ternary glasses the variations in the moduli are consistent with the nature of the structural units formed at various compositions. The variations in the Debye and glass transition temperatures and the average dimensionality of the glasses are also examined on the basis of a structural model of the glasses proposed earlier. The longitudinal modulus, shear modulus and Poisson ratio are found to vary linearly as a function of the covalent bond energy density and also as a function of the product of total cohesive energy density and average dimensionality.