Crystal growth kinetics in Lennard-Jones and Weeks-Chandler-Andersen systems along the solid-liquid coexistence line

Kinetics of crystal-growth is investigated along the solid-liquid coexistence line for the (100), (110) and (111) orientations of the Lennard-Jones and Weeks-Chandler-Andersen fcc crystal-liquid interface, using non-equilibrium molecular dynamics simulations. A slowing down of the growth kinetics along the coexistence line is observed, which is mostly a temperature effect, with other quantities such as the melting pressure and liquid self-diffusion coefficient having a negligible impact. The growth kinetics of the two potentials become similar at large values of the melting temperature and pressure, when both resemble a purely repulsive soft-sphere potential. Classical models of crystallization from the melt are in reasonable qualitative agreement with our simulation data. Finally, several one-phase empirical melting/freezing rules are studied with respect to their validity along the coexistence line.

Ronald Benjamin, Jürgen Horbach · 2015