Barium Potassium Bismuth Oxide Synthesis and Physical Properties

ABSTRACTA series of compounds Ba1−xKxBiO3 have been prepared and characterized over the range of compositions ranging from x = 0.3 to 0.5. A neutron powder diffraction analysis has been carried out for the composition x = 0.4 at room temperature and at 10 K. Examination of the superconducting properties as a function of x indicates superconductivity occurs over a narrow range of compositions close to x = 0.4, with Tc of 29 K. Specific heat measurements indicate conventional electron-phonon interactions may play a role in promoting superconductivity in Ba.6K.4BiO3. Magnetization loops and examination of the time dependent magnetization indicate that Ba.6K.4BiO3 has a low value of Jc due to very weak pinning.