The orientational relationship between monoclinic β-Ga2O3 and cubic NiO

The orientational relationship between beta-Ga2O3 and NiO was studied by X-ray diffraction measurements and cross-sectional high resolution transmission electron microscopy. A beta-Ga2O3 thin film was formed on a (100) NiO layer on a (100) MgO substrate by gallium evaporation in an oxygen plasma. It was found that the resulting beta-Ga2O3 had a four-fold domain structure satisfying both (100) beta-Ga2O3 parallel to (100) NiO and (010) beta-Ga2O3 parallel to {011} NiO. A gamma-Ga2O3 layer was observed at the interface between the beta-Ga2O3 and the NiO. An NiO film was also formed on a (100) beta-Ga2O3 single-crystal substrate by the sol gel method. An epitaxial (100) NiO film was formed on a (100) beta-Ga2O3 substrate, and satisfied (011) NiO parallel to (010) beta-Ga2O3. The crystal orientations of beta-Ga2O3 on (100) NiO and NiO on (100) beta-Ga2O3 can be explained using atomic arrangement models of the (100) plane of NiO and the (100) plane of beta-Ga2O3. (C) 2016 Elsevier B.V. All rights reserved.