Cerâmica (Jun 2013)
Zinc-gallium oxynitride powders: effect of the oxide precursor synthesis route
Abstract
Zinc-gallium oxynitride powders (ZnGaON) were synthesized by nitridation of ZnGa2O4 oxide precursor obtained by polymeric precursors (PP) and solid state reaction (SSR) methods and the influence of the synthesis route of ZnGa2O4 on the final compound ZnGaON was investigated. Crystalline single phase ZnGa2O4 was obtained at 1100 ºC / 12 h by SSR and at 600 ºC / 2 h by PP with different grain sizes and specific surface areas according to the synthesis route. After nitridation, ZnGaON oxynitrides with a GaN würtzite-type structure were obtained in both cases, however at lower temperatures for PP samples. The microstructure and the specific surface area were strongly dependent on the oxide synthesis method and on the nitridation temperature (42 m²g-1 and 5 m²g-1 for PP and SSR oxides treated at 700 °C, respectively). The composition analyses showed a strong loss of Zn for the PP samples, favored by the increase of ammonolysis temperature and by the higher specific surface area.
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