Nanoindentation-induced phase transformation between silicon carbide (SiC) polymorphs has been investigated by a combined study of transmission electron microscopy and first principles calculations. In situ nanoindentation of 4H-SiC single crystals revealed the occurrence of a phase transformation from 4H to 3C in the vicinity of a crack. First principles calculations pointed out an extremely low energy barrier for this phase transformation, which could be attributed to the very smooth transition in the atomic and electronic structures across the 3C/4H interface. The phase transformation from 4H to 3C may retard the propagation of cracks and reduce the band gap of SiC. (C) 2018 Elsevier B.V. All rights reserved.
