Schematic illustrating the various non-degenerate polytype configurations observed in SiC arranged in order of increasing complexity of model. For convenience the basic common polytypes are shown as vertical and hatched lines while the LPP/1DD regions as darker typeface.

(a) The various sandwiches that have been observed containing LPP/1DD layers as fillings or as an asymmetric layer, in the case of the open sandwich, on only one face of the crystal are shown. It should be noted that No example of the reverse sandwich has been observed in this survey and the authors have included it for completeness.

(b) Multipolytypes of silicon carbide occur in roughly equal proportion in the survey representing approximately 20% of the sample. While only the 6H single polytype has been observed as a stand-alone, combinations of either 4H and/or 15R polytypes syntactically coalesce alongside the 6H to form doubles and triples.