Synchrotron X-ray and ab initio studies of β-Si3N4

Abstract

Almost absorption- and extinction-free single-crystal synchrotron X-ray diffraction data were measured at 150, 200 and 295 K for β-Si3N4, silicon nitride, at a wavelength of 0.7 Å. The true symmetry of this material has been the subject of minor controversy for several decades. No compelling evidence favouring the low-symmetry P63 model was identified in this study.