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A comparative structural study has been carried out on gallium oxynitride powders using XRD and Raman spectroscopy. Gallium oxynitrides have been prepared by ammonolysis of either NiGa2O4 ternary oxide or the citrate method-derived amorphous oxide. Their crystal chemistry is different and appears to be influenced by the nature of the oxide precursor: whereas gallium oxynitride obtained from amorphous gallium oxide crystallizes with the common wurtzite structure, gallium oxynitride obtained from NiGa2O4 crystallizes with an original structure that we have identified as the carborundum II (B6) structure type or 6H–SiC. As far as we know, this is the first 6H–SiC structure found in gallium oxynitride powders.

Gallium I 2200 Preparation and Lithium Doping of Gallium Oxynitride by Ammonia Nitridation via a Citrate PrecursorRoute. -(Ga 0.89 0.11 )(N 0.66 O 0.34 ) ( : Ga vacancy) is synthesized by nitridation of a precursor obtained from an aqueous solution of GaNO3 and citric acid in a flow of NH3 at 750-850°C. Approximately 10 at.% Li + is doped into the gallium oxynitride using an aqueous solution of LiNO3. The samples are characterized by powder XRD, electrical measurements, and Raman, photoluminescence, and UV/VIS diffuse reflectance spectroscopy. The new compound Li 2 Ga 3 NO 4 is isostructural to hexagonal GaN and crystallizes in the space group P63mc. It displays yellow luminescence under excitation at 254 nm. -(KIKKAWA*, S.; NAGASAKA, K.; TAKEDA, T.; BAILEY, M.; SAKURAI, T.; MIYAMOTO, Y.; J. Solid State Chem.