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

• Published in: Journal of solid state chemistry Vol. 315; p. 123508
• Main Authors: Matsuishi, Satoru, Iwasaki, Daiki, Hosono, Hideo
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.11.2022
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2022.123508

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 Pm3¯m 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. High-pressure solid-state metathesis reaction yields perovskite-type LaWN3, unlike ambient pressure ammonolysis yields the oxynitride. [Display omitted] •High-pressure synthesis of LaWN3 binary nitride.•Solid-state metathesis (HPSSM) reaction of oxygen-free precursors.•Perovskite-type structure with pseudo-cubic symmetry.•Less residual oxygen compared to that in conventional oxynitrides.•Insulating/semiconducting nature with indirect band gap of ∼1.2 ​eV.