Synthesis,Crystal Structure,and High Temperature Behavior of Zr3N4

A red-brown zirconium nitride was prepared by ammonolysis of ZrCl₄. Chemical analysis leads to a composition of Zr₃N₄. It is not possible to distinguish between the space groups Pnam and Pna2₁ in the case of Zr₃N₄ using powder methods. The lattice constants are: a = 972.94(5) pm, b = 1081.75(6) pm, c = 328.10(1) pm (Z = 4). X-ray powder diffraction data were used for structure refinement. The high temperature behavior was investigated with in situ XRD methods. Zr₃N₄ decomposes into ZrN and nitrogen gas at temperatures above 800°C.