# $La_{0.9}Sr_{0.1}Ga_{0.8}M_{0.2}O_{3–\delta}$ (M = Mn, Co, Ni, Cu or Zn): Transition metal-substituted derivatives of lanthanum–strontium–gallium–magnesium (LSGM) perovskite oxide ion conductor

Litty, Sebastian and Shukla, AK and Gopalkrishana, J (2000) $La_{0.9}Sr_{0.1}Ga_{0.8}M_{0.2}O_{3–\delta}$ (M = Mn, Co, Ni, Cu or Zn): Transition metal-substituted derivatives of lanthanum–strontium–gallium–magnesium (LSGM) perovskite oxide ion conductor. In: Bulletin of Materials Science, 23 (3). pp. 169-173.

Perovskite oxides of the general formula, $La_{0.9}Sr_{0.1}Ga_{0.8}M_{0.2}O_{3–\delta}$ for M = Mn, Co, Ni, Cu and Zn, have been prepared and investigated. All the oxides exhibit high electrical conductivities $(\sigma ~ 10^{–2} S/cm at 800°C)$ comparable to that of the best perovskite oxide ion conductor, $La_{0.9}Sr_{0.1}Ga_{0.8}Mg_{0.2}O_{2.85}$ (LSGM)$(\sigma ~ 8\times 10^{–2} S/cm at 800°C)$. While M = Mn, Co, Ni, Cu members appear to be mixed conductors with a variable electronic contribution to the conductivity, especially at high oxygen partial pressures $(pO_2 \geq 1 atm)$, arising from mixed-valency of the transition metals, the M = Zn(II) phase is a pure oxide ion conductor exhibiting a conductivity $(\sigma ~ 1.5 \geq 10^{–2} S/cm at 800°C)$ that is slightly lower than that of LSGM. The lower conductivity of the M = Zn(II) derivative could be due to the preference of Zn(II) for a tetrahedral oxygen coordination.