Atomic replacement effect on electron charge density of perovskite oxides

Charge density distributions of cubic SrTiO₃ have been investigated related to the atomic replacement effect on the phase transition, by analyzing the synchrotron-radiation X-ray powder-diffraction data by the MEM (Maximum Entropy Method)/Rietveld method. The chemical bonding natures between constituent atoms in cubic SrTiO₃ are compared with those in cubic BaTiO₃ that we investigated previously at the same temperature. The Characteristic charge density distribution around the O atom, which may present a clue what kind of phase transition occurs in the cubic perovskite oxide, is found in SrTiO₃.