Studies on a group of silicon carbide structures

Abstract

Morphological and structural details of silicon carbide type 141R are given. This polymorph, having a structure represented by the zigzag sequence 3333333333333332, is a member of the '3...2' rhombohedral series proposed by Ramsdell [Am. Mineralogist 32, 64 (1947)]. A detailed study of the '3...2' series is undertaken, resulting in an empirical mechanism which can be used for the direct determination of the structure of any member of this series. Using this means the structure of the new polymorph 393R is suggested.