Size dependence of twin formation energy in cubic SiC at the nanoscale

Abstract

This letter reports the size dependence of twin formation energy in cubic SiC at the nanoscale, while the bulk value is nearly zero. Atomic edges surround the twin boundary of SiC nanowires, and they are responsible for the finite twin formation energy and its size dependence. Based on classical molecular statics calculations, the average formation energy of convex and concave edges is 73meV∕nm. Effectively, the twin formation energy is inversely proportional to the length of edges surrounding the twin boundary. Results of this letter make it possible to understand large separations of twin boundaries in SiC nanowires.