1208.1013 (Benjamin Scheifele et al.)

Heterogeneous Nucleation in the Low Barrier Regime    [PDF]

Benjamin Scheifele, Ivan Saika-Voivod, Richard K. Bowles, Peter H. Poole

In simulations of the 2D Ising model, we examine heterogeneous nucleation induced by a small impurity consisting of a line of 1 fixed spins. As l increases, we identify a limit of stability beyond which the metastable phase is not defined. Approaching the limit of stability, we evaluate G(n), the free energy when the system contains an $n$-site cluster of the stable phase attached to the impurity. We show that the conventional definition of the nucleation barrier as the difference between the minimum and the maximum (at $n=n^\ast$) of G(n) gives poor results when used to predict the nucleation time (from classical nucleation theory) and the size of the critical cluster (from the nucleation theorem). However, if the barrier is defined relative to a reference state that considers the entire configuration space of the metastable phase (i.e. all $nView original: http://arxiv.org/abs/1208.1013