Abstract

The structures of Σ = 3 incoherent twin boundaries in β‐SiC were studied by high‐resolution electron microscopy (HREM), electron energy‐loss spectroscopy (EELS), and theoretical calculation. Especially, the existence of the variety of structures of Σ = 3 incoherent twin boundaries was found by HREM. All the observed Σ = 3 incoherent twin boundaries consist of arrays of structural units composed of five‐, six‐, and seven‐membered rings, although the kinds or features of structural units change according to the lengths or circumstances of the boundaries. It is shown from the tight‐binding calculations that the grain boundary energy becomes lower when the reconstructed 〈011〉 bonds are occupied by Si‐Si bonds than C‐C bonds. The grain boundary energy of the symmetrical structural unit composed of five‐seven‐six‐membered rings is lower than that of the asymmetric one, however, the difference between those is small. EELS analysis indicated that C atoms exist at grain boundaries on the similar condition of grain interior. The observed results of HREM and EELS can be explained by the theoretical results.

This content is only available as a PDF.
You do not currently have access to this article.