Understanding the effect of oxide components on proton mobility in phosphate glasses using a statical analysis approach

Abstract

The models to describe the proton mobility (μ_H) together with the glass transition temperature (T_g) of proton conducting phosphate glasses employing the glass composition as descriptors have been developed using a statical analysis approach. According to the models, the effects of additional HO_1/2, MgO, BaO, LaO_3/2, WO₃, NbO_5/2, BO_3/2 and GeO₂ as alternative to PO_5/2 were found as following. μ_H at T_g is determined first by concentrations of HO_1/2 and PO_5/2, and μ_H at T_g increases with increasing HO_1/2 concentration and decreasing PO_5/2. The component oxides are categorized into three groups according to the effects on μ_H at T_g and T_g. The group 1 oxides increase μ_H at T_g and decrease T_g, and HO_1/2, MgO, BaO and LaO_3/2 and BO_3/2 are involved in this group. The group 2 oxides increase both μ_H at T_g and T_g, and WO₃ and GeO₂ are involved in this group. The group 3 oxides increase T_g but do not vary μ_H at T_g. Only NbO_5/2 falls into the group 3 among the oxides examined in this study. The origin of the effect of respective oxide groups on μ_H at T_g and T_g were discussed.