In this study, we investigated the phase and microstructural changes induced by heat-treatment of indium hydroxide nanoparticles produced by precipitation at various temperatures for different holding times. A white powder was obtained after heating for various times at temperatures of 150-900 oC. We also investigated changes in the specific surface area of indium oxide prepared by heating the precipitate between 200 and 900 oC. Finally, we propose a model for the formation of indium oxide powder from the precipitate. The model includes processes such as the formation of bundles of rod-shaped particles, generation of voids in the bundle from the evaporation of crystallized water, strong re-agglomeration of rod-shaped particles, collapse of the rod structure, formation of spherical agglomerates, heterogeneous crystal growth, and homogeneous crystal growth.

Keywords: Indium hydroxide, Precipitation method, Transparent conductive oxide, Heat-treatment, Raw material.