Synthesis and Crystal Structure of Sr2ScBiO6

A new complex oxide Sr 2 ScBiO 6 was synthesized by a solid state reaction in air. The compound is stable up to 1150°C and acquires the desired oxygen stoichiometry at 850°C. The crystal structure was determined using powder X-ray diffraction, electron diffraction, and high-resolution electron microscopy. Sr 2 ScBiO 6 has a perovskite-derived pseudocubic face-centered unit cell ( a =8.1816(3) A) and a rock-salt ordering of Sc 3+ and Bi 5+ over the B positions. Electron microscopy investigation reveals that the real structure is of the La 2 NiRuO 6 type, monoclinic with cell parameters a ≈ b = a per √2≈5.785 A, c =2 a per ≈8.182 A, and P2 1 / n space group. The structure can be described by an a + b − b − system of the BO 6 octahedral tilting. The presence of numerous twin domains is a characteristic feature of this compound.