Study of charge relaxation in poled silicate glasses

Abstract

We have characterized relaxation peaks observed in the thermally stimulated relaxation current (TSDC) of thermally-poled soda-lime glass in 250-780°C temperature range. We relate the low-temperature (below glass transition) peak to chemical potential driven relaxation that is ionic diffusion. This peak tends to shift towards higher temperatures and to disappear in stronger-poled glasses. Two registered high-temperature (above glass transition, Tg) peaks are supposedly related to electric potential driven processes. Studies of the compositional profiles of poled glasses after secondary thermal processings allowed us concluding that the lower temperature peak found above Tg is supposedly related to the migration of univalent ions (sodium and potassium), while the higher-temperature one is because of the migration of bivalent calcium ions.