Synthesis and oxide ion conductivity of new layered perovskite La1−xSr1+xInO4−d

New La1−xSr1+xInO4−d compounds were synthesized and identified by the powder X-ray diffraction (XRD) method. In the composition range of 0≤x≤0.2, La1−xSr1+xInO4−d compounds were prepared by heating at 1573 K in air for 36 h as single phase. Rietveld analysis of their XRD data revealed that La1−xSr1+xInO4−d compounds possess the orthorhombic K2NiF4-type structure. Measurement of electrical conductivity as a function of oxygen partial pressure (PO2) showed oxide ion conduction for the samples below PO2=10−12 atm for x=0 and below 10−5 atm for x=0.1 and 0.2. At high oxygen partial pressure, it also showed contribution of hole conduction for the samples.