Topochemically Reduced Iridium oxide phases

There is growing interest in the topochemical reduction of transition metal oxides to form oxyhydride (containing both O2- and H- anions) or oxide-ion deficient materials, as these phases can exhibit electronic and magnetic behaviour which is strikingly different from the corresponding all-oxide starting materials. Following this synthesis strategy we have prepared a series of reduced/anion-exchanged phases from iridium-containing complex oxides: LaxSr4-xCoIrO8 (x = 0, 0.5, 1, 2) Ruddlesden-Popper phases have been converted to the corresponding LaxSr4-xCoIrO6H¬y phases; LaxSr2CoIrO6 (x = 0, 1) double-perovskite oxides have been converted to the corresponding LaxSr2CoIrO4 and LaxSr2CoIrO4Hy phases, and hexagonal Ba3CoIr2O9 has been converted to Ba3CoIr2O6Hy and Ba3CoIr2O8Hy. We propose to collect high resolution neutron diffraction data from these reduced materials to determine their crystal structures (especially the location of the hydride ions) and also their low-temperature magnetic structures.