Atomistic and lattice model of a grain boundary defaceting phase transition.
Recent calculations have shown that grain boundary (GB) stress is too small to stabilize finite GB facets, suggesting that the existing theory of GB defaceting phase transitions is incomplete. We perform molecular dynamics calculations, which show a reversible phase transition at approximately 400 K with a concerted shuffle of two atoms at the facet junction as the elementary excitation. Based on this excitation we formulate an appropriate lattice model, perform Monte Carlo simulations, and establish an analytical relationship between the elementary excitation energy and the transition temperature.
Daruka
István
I
Sandia National Laboratories, Livermore, California 94550, USA.
Hamilton
J C
JC