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

The models to describe the proton mobility (μH) together with the glass transition temperature (Tg) 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 HO1/2, MgO, BaO, LaO3/2, WO3, NbO5/2, BO3/2 and GeO2 as alternative to PO5/2 were found as following. μH at Tg is determined first by concentrations of HO1/2 and PO5/2, and μH at Tg increases with increasing HO1/2 concentration and decreasing PO5/2. The component oxides are categorized into three groups according to the effects on μH at Tg and Tg. The group 1 oxides increase μH at Tg and decrease Tg, and HO1/2, MgO, BaO and LaO3/2 and BO3/2 are involved in this group. The group 2 oxides increase both μH at Tg and Tg, and WO3 and GeO2 are involved in this group. The group 3 oxides increase Tg but do not vary μH at Tg. Only NbO5/2 falls into the group 3 among the oxides examined in this study. The origin of the effect of respective oxide groups on μH at Tg and Tg were discussed.