Temperature-Induced Phase Transition of In 2 O 3 from a Rhombohedral Structure to a Body-Centered Cubic Structure

We report an experimental study on the temperature-induced phase transition of three-dimensional nanosheet-based flower-like microspheres (NBFMs) of In2O3. Using InOOH as precursor, rhombohedral-In2O3 NBFMs are fabricated. Temperature-induced phase transition of In2O3 NBFMs from a rhombohedral (rh) structure to a body-centered cubic (bcc) structure is examined by Raman spectroscopy and x-ray diffraction. The critical phase transition temperature is found to be about 500°C. Photoluminescence (PL) spectra of In2O3 are measured before annealing and after annealing at different temperatures. The PL spectral results provide further evidence for the phase transition, confirming the fabrication of bcc-In2O3 NBFMs via a simple annealing method.