Oxygen Ionic and Electronic Transport in LaGa_1-xNi_xO_3-δ Perovskites

Author： Yaremchenko A.A. Kharton V.V. Viskup A.P. Naumovich E.N. Lapchuk N.M. Tikhonovich V.N.

ISSN： 0022-4596

Source： Journal of Solid State Chemistry, Vol.142, Iss.2, 1999-02, pp. : 325-335

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Abstract

Formation of the LaGa_1-xNi_xO_3-δ solid solutions with perovskite structure was ascertained in the concentration range of 0≤x≤0.5. Substitution of gallium with nickel results in increasing oxygen nonstoichiometry and electronic and ionic conductivities. The oxygen ion transference numbers in air at 1070–1220 K determined by the Faradaic efficiency measurements do not exceed 0.005. Oxygen permeation fluxes through LaGa_1-xNi_xO_3-δ were found to increase with nickel content and to be limited predominantly by the bulk ionic conductivity. Reducing oxygen partial pressure leads to decreasing electronic transport and increasing ionic conductivity. Thermal expansion coefficients of the ceramics are in the range of (10.8–11.6) ×10^-6 K^-1.