Advances in Gallium Oxonitride Ceramics: A New Class of Materials in the System Ga-O-N

This research news highlights the history, synthesis and new developments of gallium oxonitride phases. Many practical applications are expected of this class of materials because of its analogy to aluminium oxonitride phases. A new approach to gallium oxonitride ceramics is a synthesis pathway starting from a precursor that provides gallium simultaneously bonded to nitrogen and oxygen on a molecular level. One suitable precursor is the dimethylamine adduct of gallium tris-(t-butoxide), Ga(OtBu)3·HNMe2. The optimization of the pyrolysis process was controlled by analyzing the nitrogen to oxygen content and the reduction of carbon content in the ceramic. The samples were investigated using FTIR spectroscopy and elemental analysis. The degree of crystallinity was determined by transmission electron microscopy in combination with an electron energy loss spectrometer. The precursor-derived gallium oxonitride ceramic remains nanocrystalline up to 600 °C and reacts to GaN with the wurtzite type structure by loss of all oxygen in an ammonia atmosphere at temperatures above 600 °C