The effect of adding small amounts of rare-earth cations was investigated in a study of La0.8Sr0.2Ga0.8Mg0.2O3. It was found that the addition of small amounts of rare-earth cations to La sites in LaGaO3 was effective in suppressing hole conduction under high O partial pressures, although the electrical conductivity decreased slightly. In particular, the perovskite, (La0.9Nd0.1)0.8Sr0.2Ga0.8Mg0.2O3, exhibited almost pure oxide ionic conduction at O partial pressures of between 1 and 10-21atm. The conductivity attained a value of 0.32S/cm at 1223K.

T.Ishihara, H.Matsuda, Y.Takita: Solid State Ionics, 1995, 79, 147-51