Preparation of ultrafine InN powder by the nitridation of In2O3 or In(OH)3 and its thermal stability

Abstract

Crystalline InN powder has been prepared by the nitridation of In₂O₃ and In(OH)₃ with NH₃ gas for the first time, and ultrafine InN powder in the size range 50–300 nm and with a specific surface area of 8 m² g⁻¹ has been obtained using In₂O₃ nanoparticles as the starting material. The resulting powders were characterized by XRD, FE-SEM, TEM, TG-DSC and BET surface area techniques. It was found that nanosized In₂O₃ was completely converted into InN at 600 °C within 8 h. The thermal stability of the ultrafine InN powder in air and under a nitrogen atmosphere was also investigated. It was observed that InN began to be oxidized into In₂O₃ at 389 °C and decomposed in the narrow temperature range of 595–696 °C in flows of air and N₂, respectively.