Gas-Phase Reaction of Trimethylgallium and Ammonia:  Experimental Determination of the Equilibrium Constant and ab Initio Calculations

The equilibrium constant for the reaction of trimethylgallium and ammonia has been determined at 40−100 °C via direct pressure measurements. The reaction enthalpy found from experimental data (−15.2 ± 1.5 kcal/mol) is in good agreement with the value obtained from ab initio calculations (−15.9 kcal/mol) using a series of Dunning's basis sets. Presented data should be useful for modeling of gallium nitride chemical vapor deposition reactors as well as for further theoretical analysis of thermodynamic and kinetic processes in gallium chemistry.