Debye function analysis of nanocrystalline gallium oxide γ-Ga2O3

The metastable nanocrystalline gamma-Ga2O3 with the particles' dimensions about 2 nm was prepared by coprecipitation method and its structure was studied using X-ray powder diffraction. The corresponding diffraction pattern is characterized by a strong broadening of diffraction peaks. The Debye function analysis method (DFA) was applied to calculate the full profile of the XRD pattern for the first time. Earlier reported structural models of the gamma-Ga2O3 were examined with respect to experimental diffraction data. The influence of crystallite sizes on the diffraction pattern was considered. The obtained structure of the disordered gamma-Ga2O3 has vacancies in 8a and 16d spinel positions and additional atoms in 8b, 16c and 48f non-spinel positions. The proposed structure differs from those reported by the ratio between occupancies of the tetrahedral and octahedral gallium positions.