The synthesis of high purity, single-phase gallium nitride (GaN) powder has been achieved through the reaction between molten Ga and ammonia (NH3) using Bi as a catalyst. In this simple apparatus, 25 g Ga can be fully, stoichiometrically converted into GaN within 5 h. The optimum temperature, NH3 flow rate and reaction time in this hot wall tube furnace were 1000 degrees C, 500 standard cubic centimeters per minute (sccm) and 5 h, respectively. The synthesized powder was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), glow discharge mass spectrometry (GDMS), Raman spectroscopy, and cathodoluminescence (CL). All of these techniques indicated high purity, hexagonal polycrystalline GaN with 1 20 mu m across plate like grains. (c) 2005 Elsevier B.V. All rights reserved.