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

Abstract

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.