Synthesis of perovskite-type LaWN3 by high-pressure solid-state metathesis reaction

Perovskite-type LaWN3 was synthesized by the solid-state metathesis reaction of LaCl3, WCl6, and Li3N under a pressure of 5 GPa and a temperature of 1573 K. The amount of oxygen in the synthesized sample is smaller than that in the sample prepared by the conventional ammonolysis of La2W2O9. The x-ray diffraction pattern of resulting phase can be fitted by either the meta-stable cubic structure with a Pm3m space group or the ground-state rhombohedral structure with an R3c space group. The indirect bandgap of-1.2 eV and the direct band gap of-2.2 eV are consistent with those of the rhombohedral structure calculated by the density functional theory calculation with the HSE06 hybrid functional.

Automated summary

Perovskite-type LaWN3 was synthesized via solid-state metathesis reaction and showed a lower oxygen content compared to the sample prepared by conventional ammonolysis. The x-ray diffraction pattern indicated either a meta-stable cubic structure or a ground-state rhombohedral structure. The synthesized material exhibited a certain band gap.