Grain Boundaries in Silicon from Zero Temperature through Melting

The results of atomistic simulations of twist grain boundaries in covalent silicon are presented and compared with similar studies in metals. Three aspects are discussed in detail: (i) the zero-temperature structure-energy correlation, (ii) the elastic anomalies near a twist boundary at zero temperature, and (iii) the high-temperature stability of a boundary and its role in thermodynamic melting. In each case striking similarities with studies on metals are found, which are attributed to the important role played by atoms in close proximity. By contrast the covalent nature of bonding in silicon appears to play only a minor role.