Mixed electronic and ionic conductivity of LaCo(M)O3 (M=Ga, Cr, Fe or Ni).: V. Oxygen permeability of Mg-doped La(Ga, Co)O3−δ perovskites

• Published in: Solid state ionics 1999-05, Vol.120 (1-4), p.65-74
• Main Authors: Yaremchenko, A.A., Kharton, V.V., Viskup, A.P., Naumovich, E.N., Tikhonovich, V.N., Lapchuk, N.M.
• 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 cobaltite-gallate; 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: 0167-2738; 1872-7689
• DOI: 10.1016/S0167-2738(98)00469-X

The LaGa1−x−yCoxMgyO3−δ solid solutions with rhombohedrally-distorted perovskite structure were ascertained to form in the concentration range of 0≤y≤0.10 at x=0.60 and 0≤y≤0.20 at x=0.35–0.40. Increasing cobalt content results in increasing electrical conductivity and thermal expansion of the perovskites. Thermal expansion coefficients of the LaGa1−x−yCoxMgyO3−δ ceramics were calculated from the dilatometric data to vary in the range of 12.4–19.8×10−6 K−1 at 300–1100 K. Doping La(Ga,Co)O3−δ solid solutions with magnesium leads to increasing oxygen nonstoichiometry, electronic and oxygen ionic conductivity. Oxygen permeation fluxes through LaGa1−x−yCoxMgyO3−δ membranes were found to be limited by the bulk ionic conduction and to increase with magnesium concentration, being essentially independent of cobalt content.