FCC vs HCP transformation of small BCC clusters and asymmetry of the BCC-HCP transition

Abstract

The free Gibbs energy gradient descent method, which allows for zero-point energy and temperature related effects, was applied for a structure relaxation of initially BCC clusters with several thousands atoms. The mechanism of the transition to the FCC vs HCP structure depends on size, shape, temperature and initial lattice distortion. Multidomain structures may result from the BCC-HCP transition. Domain boundaries as well as the found intermediate structures are metastable, evolve in time and potentially important in connection with the phenomenon of supersolidity. © 2009 IOP Publishing Ltd.