Formation and microstructural characterization of In2O3 sheath layer on InN nanostructures

An In2O3 sheath layer was formed on an InN nanostructure by a rapid thermal oxidation process. Rounding and bursting phenomena were observed as the progression of the oxidation process was followed. InN/In2O3 core-shell structures were identified as intermediate structures. After a 20 min oxidation, the InN nanostructures were completely transformed to an In2O3 phase. InN and In2O3 had wurtzite (WZ) and body-centered cubic (BCC) structures, respectively. The preferred orientation relationship of <1 1 2 ¯ 0>WZ//<1 1 0>BCC and {0 0 0 1}WZ//{ 1 ¯ 1 1}BCC was observed between InN and In2O3. Cracks in burst nanostructures were generated at the corners and penetrated along the <1 1 2 ¯ 0> directions.