Synthesis Routes and Characterization of High‐Purity, Single‐Phase Gallium Nitride Powders

Synthesis of high‐purity, single‐phase gallium nitride powder has been achieved in a hot‐wall tube furnace via (i) the reaction of gallium with ammonia (NH 3 ) and (ii) the conversion of gallium oxide (Ga 2 O 3 ). For complete reaction, the optimum temperatures, NH 3 flow rates, and boat positions relative to the NH 3 inlet were 975°C, 400 standard cubic centimeters per minute (sccm), and 50 cm, respectively, for the gallium‐NH 3 reaction, and 1050°C, 500 sccm, and 50 cm, respectively, for the Ga 2 O 3 conversion. Polyhedra of various shapes were obtained from both processes; some rod‐shaped crystals also were observed in the material derived from Ga 2 O 3 .