Relative Thermal Stability of Α- and Β-Modifications of Ge3n4

Abstract

In this article the processes occurring when heating pure α-, β-Ge3N4 and their mixtures in a low dynamic vacuum, as well as in hydrogen and water vapor are discussed. Relative thermal stability of pure α- and β-modifications of Ge3N4 and their mixtures is studied. In vacuum α-Ge3N4
dissociates at temperatures of T ≥ 740°C, and β-Ge3N4 at T ≥ 780°C. At lower temperatures both modifications are sublimated. Sublimation heat of α-Ge3N4 is ~245 kJ/mol, and of β-Ge3N4 is ~290 kJ/mol. The predominant thermal stability of β-Ge3N4 is also evident in hydrogen and water vapor media.

Keywords: Germanium nitride, α-Ge3N4, β-Ge3N4, thermal stability, sublimation dissociation.