Oxygen Ionic and Electronic Transport in LaGa1−xNixO3−δPerovskites

• Published in: Journal of solid state chemistry 1999-02, Vol.142 (2), p.325-335
• Main Authors: Yaremchenko, A.A., Kharton, V.V., Viskup, A.P., Naumovich, E.N., Lapchuk, N.M., Tikhonovich, V.N.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Diffusion in solids; Electronic transport in condensed matter; Exact sciences and technology; ionic conductivity; lanthanum gallate–nickelate; Mixed conductivity and conductivity transitions; mixed conductor; oxygen permeability; perovskite; Physics; Self-diffusion and ionic conduction in nonmetals; Transport properties of condensed matter (nonelectronic)
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.1998.8041

Formation of the LaGa1−xNixO3−δsolid 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 LaGa1−xNixO3−δwere 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) ×10−6K−1.