Discrimination between dipolar and space-charge relaxation by thermally stimulated current spectroscopy: application to several alkali-exchanged mordenites

Abstract

Thermally stimulated current (TSC) spectroscopy is widely used to understand dielectric relaxation in complex solid systems. However, when these systems contain free and bound charges, it appears that TSC spectra exhibit multicomponent signals, due both to dipolar and to space-charge relaxation. In this work, we propose an experimental method to identify clearly and then separate the space-charge contribution from the dipolar current, in ionically conducting solids. This method is based on the comparison between global and fractional thermally stimulated current procedures and is applied to analyse the dielectric response of several alkali-exchanged mordenites (with exchange of , and for ).