Preparation of ABi2O6 (A = Mg, Zn) with the trirutile-type structure

New bismuth oxides, ABi2O6, (A = Mg, Zn) with the trirutile-type structure were prepared by low-temperature hydrothermal reaction using NaBiO3 · nH2O as a starting material. The tetragonal lattice parameters are a = 4.8260(1) and c = 9.7190(1) إ for A = Mg and a = 4.8386(1) and c = 9.7422(3) إ for A = Zn. The crystal structure of MgBi2O6 was refined using neutron diffraction data giving final R factors of Rwp = 12.6 and Rp = 9.64%. Both bismuth oxides decomposed by reduction of Bi5+ to Bi3+ above 380 °C.