Preparation and thermal decomposition of indium hydroxide

Indium hydroxides were prepared by the mixing of aqueous indium nitrate solution with sodium or ammonium hydroxide solutions under various conditions. The thermal decomposition of the resulting materials was examined by thermogravimetry, differential thermal analysis, X-ray diffraction study and infrared spectroscopy. It has been found that sodium hydroxide solution is more suitable than the addition of ammonium hydroxide solution to prepare indium hydroxide in well crystallization; the thermal decomposition of indium hydroxide, in which the composition is In(OH)3·xH2O where x£2, proceeds according to the following process: In(OH)3·xH2O®cubic In(OH)3®cubic In2O3