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)over bar> 0>(WZ)//<1 1 0>(BCC) and {0 0 0 1}(WZ)//{(1) over bar 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)over bar> 2 0> directions. (C) 2010 Elsevier B.V. All rights reserved.