Young's Modulus and Compositional Parameters of Oxide Glasses

The Young's moduli of various oxide glasses (silicate, borate, phosphate, and tellurite) were measured using an ultrasonic method. To predict the Young's moduli of the oxide glass systems, empirical compositional parameters G i and V i , based on the Makishima‐Mackenzie theory, were obtained, where G i is the dissociation energy and V i the packing density parameter of a single‐component oxide. The relationship between the calculated Young's modulus from the compositional parameters and the measured Young's modulus was investigated. Experimental results indicated that the Young's modulus of phosphate and tellurite glasses could not be predicted using these parameters. Thus, it was necessary to modify the G i , by considering P 2 O 5 and TeO 2 as glass network formers. As for the phosphate glass, it exhibited a layered structure that consisted of P=O double bond and three chains of P‐O bond. In this paper, the modified G i of P 2 O 5 was calculated using the assumption that the P=O double bond is a nonbridging bond and does not contribute to Young's modulus. In the case of tellurite glass, the glass structure is mainly composed of TeO 4 trigonal pyramids, and the addition of other oxides results in structural changes to the TeO 3 trigonal pyramid. However, the mechanisms of such structural changes have not yet been clarified. Therefore, the modified G i of TeO 2 was calculated from the measured value using the density and Young's modulus of pure TeO 2 glass. The results revealed that the calculated values using our proposed parameter were in good agreement with measured values all through the oxide glasses.