Atomic and Electronic Structure Analysis of Σ=3, 9 and 27 Boundary, and Multiple Junction in β-SiC

Abstract

The atomic structures of Σ=3, 9 and 27 boundaries, and multiple junctions in β-SiC were studied by high-resolution electron microscopy (HREM). Especially, the existence of the variety of structures of Σ=3 incoherent twin boundaries and Σ=27 boundary was shown by HREM. The structures of Σ=3, 9 and 27 boundary were explained by structural unit models. Electron energy-loss spectroscopy (EELS) was used to investigate the electronic structure of grain boundaries. The spectra recorded from bulk, {111}Σ=3 coherent twin boundary (CTB) and {211}Σ=3 incoherent twin boundary (ITB) did not show significant differences. Especially, the energy-loss corresponding to carbon ls-to π* transition was not found. It indicates that C atoms exist at grain boundary on the similar condition of bulk.