Temperature-Induced Phase Transition of In₂O₃ 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.