Indexed on: 01 Sep '99Published on: 01 Sep '99Published in: Journal of Thermal Analysis and Calorimetry
The structural characterization, thermogravimetric analysis and electrical properties for solid solution system, (Ba1–xLax)2In2O5+x with perovskite-type structure were investigated. X-ray diffraction showed that the orthorhombic phase was in the range of 0.0<x≤0.3, the tetragonal phase 0.3<x≤0.5, and the cubic phase 0.5<x. The sharp transition of electrical conductivity shifted to a lower temperature with increasing x and disappeared at the phase boundary between the orthorhombic and tetragonal phases. This perovskite-related oxide exhibited a pure oxide-ion conduction over the oxygen partial pressure range of 1 atm to 10−3.5 atm, and the electrical conductivity reached the value of 1.6⋅10−1 (S cm−1) at 1073 K, which was nearly equal to that of the yttria stabilized zirconia. These properties were successfully explained in terms of disordered oxygen ions.