NaIrO3—A pentavalent post-perovskite

Sodium iridium (V) oxide, NaIrO3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO3, the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO3. Among the oxide post-perovskites, NaIrO3 is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO6 octahedra separated by layers of NaO8 bicapped trigonal prisms. NaIrO3 shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides.

Sodium iridium(V) oxide, NaIrO3, synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO3 post-perovskite.Figure optionsDownload as PowerPoint slideResearch highlights
► NaIrO3 post-perovskite stabilized by pressure.
► First example of a pentavalent oxide post-perovskite.
► Non-metallic and non-magnetic behavior of NaIrO3.