Crystal growth of bismuth(V) oxides from hydroxide fluxes

摘要

The first example of a 2 H-perovskite related A_3A'BiO_6 oxide, (Sr_(2.59)Ba_(0.41))NaBiO_6, with two different divalent cations on the A site, was synthesized in a reactive, mixed strontium-, barium-, sodium-hydroxide flux. (Sr_(2.59)Ba_(0.41))NaBiO_6 crystallizes in the space group R3-barc, with a = 9.9839(2) A and c = 11.8008(4) A. Crystals of isostructural oxides, Sr_3NaBiO_6 and Sr_3LiBiO_6, were also obtained from reactive Sr(OH)_2, NaOH and LiOH fluxes. Sr_3NaBiO_6 and Sr_3LiBiO_6 crystallize in the space group R3-barc with a = 9.9193(2) A, c = 11.7473(5) A and a = 9.9293(2) A, c = 11.4188(5) A, respectively. In addition, we report the crystal growth of a strontium bismuth oxyhydroxide, Sr_4(BiO_6)(OH), isolated from a reactive Sr(OH)_2 flux contained in sealed silver tubes. Sr_4(BiO_6)(OH) crystallizes in the monoclinic space group, P2_1 with a = 6.9429(8) A, b = 6.1286(7) A, c = 9.2746(10) A, and beta = 102.176(2) deg. The structure consists of layers of connected SrO_x polyhedra, with isolated BiO_6 octahedra located in every second Sr-O layer.