Ionic conduction due to oxygen diffusion in La0.8Sr0.2GaO3-δ electrolyte

Dielectric and dc measurements have been carried out on La0.8Sr0.2GaO3-delta, which has a high potential for the electrolyte material in a solid oxide fuel cell, so as to elucidate the correlation between O2- diffusion and electric conduction. A dielectric relaxation shows up in loss tangent. The relative relation of activation energies as to dielectric relaxation and dc conduction suggests the ionic conduction due to O2- diffusion assisted by free single oxygen vacancies taking place. The change of dc conductive behavior associated with attenuation of dielectric relaxation around 950 K indicates that another type of O2- diffusion dominates the ionic conduction at high temperature. (C) 2003 American Institute of Physics.