Synthesis of nanocrystal GaN powders by mechanochemical reaction

The synthesis of nanocrystal GaN by mechanochemical reaction was studied by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and optical absorption. The solid state displacement reaction of Ga/sub 2/O/sub 3/+Mg/sub 3/N/sub 2//spl rarr/2GaN+3MgO was induced by mechanical milling. Nanocrystal hexagonal GaN with an average size of 11.4 nm was obtained through subsequent annealing and removal of the by-product through washing. Optical absorption showed the bandgap of the sample is consistent with that of bulk GaN sample.