Synthesis of ultrafine gallium nitride powder by the direct current arc plasma method

Ultrafine gallium nitride (GaN) powder has been synthesized by the dc arc plasma method through the reaction of metal gallium (Ga) with the mixture gas of nitrogen ( N2) and ammonia ( NH3). The analyses of the produced powder by x‐ray diffraction, transmission electron microscopy, and selected‐area electron diffraction showed that the GaN particles in wurtzite structure consisted of nanometer‐sized polycrystals and monocrystals. The conversion of Ga to GaN was determined by the mixture ratio of NH3 and N2 in the mixture gas. The morphology of the GaN particles was mainly hexagonal with the size about 20–200 nm. When heated in air or nitrogen atmosphere, the thermostablity of the GaN powder was different.