La0.9Sr0.1Ga0.8M0.2O3�?����? (M = Mn, Co, Ni, Cu or Zn): Transition metal-substituted derivatives of lanthanum�?�strontium�?�gallium�?�magnesium (LSGM) perovskite oxide ion conductor

[摘要] Perovskite oxides of the general formula, La_0.9Sr_0.1Ga_0.8M_0.2O_{3â€�?�ð�?��?} for M = Mn, Co, Ni, Cu and Zn, have been prepared and investigated. All the oxides exhibit high electrical conductivities (𝜎∼ 10^â€�??2 S/cm at 800°C) comparable to that of the best perovskite oxide ion conductor, La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85 (LSGM) (𝜎∼ 8 Ã�? 10^â€�??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 (𝑝O₂ 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 (𝜎∼ 1.5 Ã�? 10^â€�??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.

[学科分类] 材料工程

[关键词] LSGM substitution;mixed ionicâ€�?�electronic conductors;oxide ion conductor.