Evaporation and thermodynamic properties of silicon nitride

Abstract

1. We have studied evaporation of silicon nitride by the Langmuir and Knudsen methods in the range 1688–1773°K. It has been established that during evaporation this compound dissociates into silicon (solid or liquid, depending on the temperature) and nitrogen. 2. The rate of evaporation of Si3N4 depends on the area of the effusion orifice. 3. We have determined the equilibrium pressures of nitrogen above silicon nitride in the investigated range of temperatures, the evaporation coefficient of this compound, and its standard heat of formation from the elements by the second and third laws of thermodynamics.