Nonlinear composition dependence of structure-related Young’s modulus in tin boro-phosphate glasses

We have studied the effect of B2O3 substitution by P2O5 on the elastic property of four composition series of SnO–P2O5–B2O3 glasses. The nonlinear evolution of Young’s modulus with increasing B2O3/P2O5 substitution has substantial implications for understanding the elastic properties of the oxide glasses. The observed Young’s modulus can be simulated using structural information based on the Makishima-Mackenzie model. The proportions of tetrahedral and trigonal units in the network were elucidated using high-field 11B and 31P MAS-NMR spectroscopy, but this does not entirely match the observed Young’s modulus. When the simulation is performed, satisfactory results are obtained so that some of the PO4–BO4-related bonds are not counted twice. However, the specific type of local structure, mainly consisting of tetrahedral units, is discussed.