Synthesis and structure refinement of the spinel, γ-Ge3N4

Abstract

γ-Ge3N4 is formed from α-or β-Ge3N4 at pressures greater than 12 GPa and temperatures above 100°C. It has the spinel structure, symmetry Fc3̄m, and lattice parameter a = 8.2125(1) Å. Germanium has both tetrahedral [Ge-N = 1.879(2) Å] and octahedral [Ge-N = 1.996(1) Å] coordination to nitrogen. The difference between the octahedral and tetrahedral bond lengths in this nitride is close to that expected from systematics, which were largely derived from oxides.