Ambient pressure synthesis of corundum-type In2O3

This communication reports the formation of the high-pressure modification of indium (III) oxide (so-called corundum-type or hexagonal In2O3) under ambient pressure. Corundum-type In2O3 was obtained by precipitation from the solution of indium nitrate in methanol by adding concentrated ammonia solution and subsequent calcination of the obtained precipitate at 250-500 °C. The role of the impurities and the additives in the stabilization of corundum-type In2O3 is discussed.