Edge topography and polytype boundaries
The growth of disordered layers surrounding low period polytypes, the so called reverse sandwich has not been observed in practice. In the same way Long period polytypes LPP’s are always found in coalescence with the common 6H, 15R & 4H polytypes in an idealised “sandwich”.
Bands of high defect density often in association with 1DD layers exist at many of the boundaries between different polytypes.
The ubiquitous nature of these features has been clearly highlighted using SRS XRDT and the comprehensive database on polytype neighbourism provides details on the extent of disorder in SiC.
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Acknowledgements: EPSRC, CLRC,IMG