X-ray and electron microscopy studies of polysulphur nitride

Abstract

(SN) _x crystals have been studied by a combination of scanning electron microscopy, transmission electron microscopy and rotating crystal X-ray diffraction. The studies reveal a structure of considerable complexity. The size of individual crystallites is typically a few nanometres by a few tens of nanometres, and their crystal structure is as previously reported by Mikulski and co-workers rather than that reported by Boudeulle. In bulk crystals there is a mosiac spread of approximately 10° in and about the fibre axis. A new twin mode is proposed where crystals twin about a plane perpendicular to the plane defined by individual chains arid is referred to as a (¯102)^* mode. The possibility of the existence of at least two other twin modes is also discussed. An alternative orientation relationship between the precursor dimer phase and the final polymer is presented.