Investigation of the Binary Nitrides YN, LaN and LuN by Solid-State NMR Spectroscopy

Based on their various and outstanding properties, binary nitrides are used as (synthesis) materials in industry and research. Hence, their comprehensive characterization by analytical methods is of particular interest. Since Nuclear Magnetic Resonance (NMR) spectroscopy is very sensitive to the symmetry of the electronic density distribution, it is a suitable tool for the investigation of rock-salt structure types and, especially, for those with known stoichiometry issues. Here, we report on magic-angle spinning NMR spectra of the nuclides ⁸⁹Y (I=12), ¹³⁹La (I=72) and ¹⁴N (I=1) in polycrystalline samples of YN, LaN and LuN. Due to the high symmetry of their crystal structures, the spectra of all nuclides do not exhibit anisotropic effects of significant magnitude. The resulting isotropic chemical shift values are δiso(⁸⁹Y) = 516 ppm for YN, δiso(¹³⁹La) =1294 ppm for LaN, and δiso(¹⁴N) = 457 ppm (YN), 788 ppm (LaN) and 384 ppm (LuN). The newly determined δiso(¹⁴N) values for these three binary nitrides fit well into the previously reported linear correlation between nitrogen distance to the nearest cation and isotropic chemical shift, leading to a better correlation coefficient and reduced error margins for the fit parameters.