Thermodynamical consideration of the synthesis of solid AlN from thermal plasma

The synthesis process of solid AlN in thermal plasmas was investigated theoretically by computing the equilibrium composition of the gas mixture involving nitrogen and various amounts of aluminum, oxygen and hydrogen for the temperature range between 1000 and 5500 K. The results obtained by treating the plasma as a single-gas system were combined with those which take into account the presence of solid AlN and liquid Al, to find the optimal conditions for the deposition of solid AlN. The factors determining the efficiency of this process are discussed.