OXYGEN IONIC AND ELECTRONIC TRANSPORT IN LaGa1-xNixO3-delta PEROVSKITES

摘要

Formation of the LaGa1-xNixO3-delta solid solutions with perovskite structure was ascertained in the concentration range of 0 less than or equal to x less than or equal to 0.5. Substitution of Ga with Ni results in increasing O nonstoichiometry and electronic and ionic conductivities. The O ion transference numbers in air at 1070-1220 K determined by the Faradaic efficiency measurements do not exceed 0.005. O permeation fluxes through LaGa1-xNixO3-delta were found to increase with Ni content and to be limited predominantly by the bulk ionic conductivity. Reducing pO2 leads to decreasing electronic transport and increasing ionic conductivity. Thermal expansion coefficients of the ceramics are in the range of (10.8-11.6)x10-6 K-1. 42 refs.