The oxide-ion conductivities of these Ga-based perovskite-type oxides were investigated. It was noted that the oxide-ion transference number was almost equal to unity in Sr3Ga2O6 and Ba3Ga2O6. However, the conductivities of this type of oxide were lower than 0.001S/cm, due to a low solubility of the aliovalent cations. On the other hand, doped perovskite-type oxides such as GaNdO3 or GaLaO3 exhibited high conductivities, and the transference number of the oxide ion was greater than 0.9 at O partial pressures ranging from 1 to 10-21atm. In particular, Ca-doped or Mg-doped NdGaO3 exhibited a high oxide-ion conductivity.

T.Ishihara, H.Matsuda, M.Azmi bin Bustam, Y.Takita: Solid State Ionics, 1996, 86-88[1], 197-201