Systematic X-ray diffraction study of Ba1-xKxBiO3 single crystals

Crystal structures of ten Ba1-xKxBiO3 single crystals (BKBO), grown by the anodic electrocrystallization process, were analysed to compare with previous studies on sintered powder samples. Results show that BKBO prepared in this way exhibit the same crystal symmetry of space group Pm3m for a wide range of x-values (0.39 to 0.66) and also indicates that there are solubility distrbutions both for potassium and oxygen. Oxygen deficiency lowers the superconducting transition temperature T-c. Electron density maps, calculated from room temperature X-ray diffraction data, do not show conspicuous difference between superconducting and nonsuperconducting samples.