New Sr₉Os₅O₂₃, Made Up of Quasi 1D and 2D Fragments of the Perovskite Structure

Abstract

Sr 9 Os 5 O 23 , a new strontium osmate, has been synthesized as a coarse-crystalline material from SrO 2 and Os, in a SrCl 2 flux. It crystallizes in a rather large monoclinic cell with space group, C2/c. It is a member of a newly identified homologous series Sr 2n-1 Os n O 5n-2 of compounds with n = 3, 5, 7,•••. The crystal structure consists of stacks of two-dimensional slabs of perovskite-type layers alternating with one-dimensional zigzag chains of corner sharing OsO 6 octahedra. The (Os 5+/6+ ) mixed valence title compound shows an antiferromagnetic-like transition at T N ∼ 75 K, as inferred from magnetic susceptibility data.