Perovskite solid solution powders of (La1−xSrx)(Al0.9Mg0.1)O3−δ (x = 0.1−0.4) were prepared by a coprecipitation method using corresponding aqueous solutions and ammonium carbonate solution. The X-ray diffraction patterns for the compositions of x = 0.1 to 0.4 were identified as those of hexagonal LaAlO3 solid solutions. The bulk conductivity of (La0.6Sr0.4) (Al0.9Mg0.1)O3−δ by AC method at 1V was independent of the oxygen partial pressure and 2.33 x 10−3S/cm at 800C, suggesting the oxide ion conduction. The activation energy of bulk conductivity was 111kJ/mol at 300 to 500C. The grain boundary conductivity increased from 2.02 x 10−6S/cm at Po2 = 10−15Pa to 1.11 x 10−5S/cm at Po2 = 2.1 x 104Pa at 800C. Hole conduction contributed to the increased conductivity. DC conductivity of (La0.6Sr0.4)(Al0.9Mg0.1)O3−δ depended on the applied voltage and temperature. In N2 atmosphere, hole conductivity overlapped oxide ion conductivity at a high applied voltage (E > 1V) because of the chemical reaction between positively charged oxide vacancy and N2 gas (VO•• + N2 → 2NO' + 4h•).

Synthesis and Electrical Conductivity of La1−xSrxAl0.9Mg0.1O3−δ (x = 0.1-0.4) Perovskite Solid Solution. A.Shinomiya, Y.Hirata, S.Sameshima, N.Matsunaga: IOP Conference Series - Materials Science and Engineering, 2011, 18[9B], 132015