Structural investigation of YAM-type yttrium silicon oxynitride by 15N magic-angle spinning nuclear magnetic resonance

Abstract

Structural investigations carried out by ¹⁵N MAS NMR on the yttrium silicon oxynitride Y₄Si₂O₇N₂ show that, contrary to previous work using ²⁹Si NMR, this compound does obey Pauling's second rule as regards the ordering of the oxygen and nitrogen atoms within Si₂O₅N₂ groups, with the nitrogen atoms occupying the bridging site and one terminal site. The single peak observed on ²⁹Si NMR spectra is therefore interpreted in terms of an overlap between two peaks corresponding to SiO₃N and SiO₂N₂ environments.