Preparation and characterization of the perovskites BaCe1 − xBixO3

The solid solution BaCe1 − xBixO3has been prepared and characterized by X-ray diffraction. This series of compounds has a cubic perovskite-related structure. The bismuth-rich phase (x ≥ 0.80) is isostructural to the monoclinic parent compound BaBiO3 (S.G. I 2/m), which has an ordered arrangement of Bi3+ and Bi5+ ions. The region of 0 ≤ x < 0.8 has orthorhombic symmetry (S.G. Pbnm) with a random distribution of Bi atoms. Although this structural feature is quite similar to that of the superconducting BaPb1 − xBixO3 system, all samples of BaCe1 − xBixO3 show an increase in electrical resistivity upon the Ce doping. These results are explained in terms of the competition between the bandwidth and the charge disproportionation.