Computer calculation of phase diagrams of Si-N-Cl-H, Si-C-Cl-H, and Al-N-Cl-H systems for synthesis of Si₃N₄, SiC and AIN

Using the SOLGAS-MIX computer program and JANAF thermochemical data, the equilibrium phase diagrams of Si-N-Cl-H, Si-C-Cl-H and Al-N-Cl-H systems at 1473 K and 1 atmosphere have been constructed for synthesis of Si₃N₄, SiC and AlN. Based on these phase diagrams, selection and combination of gaseous reactant chemicals are discussed with respect to the synthesis yields and total free energy change in the formation reactions. Desirable conditions for synthesis are shown under equilibrium conditions.