Lawrence Berkeley National Laboratory

Successful theories of phase transformation processes include classical nucleation theory (CNT), which envisions a local equilibrium between coexisting phases, and non--equilibrium kinetic cluster theories. Using computer simulations of the magnetization reversal of the Ising model in three different ensembles we make quantitative connections between these physical pictures. We show that the critical nucleus size of CNT is strongly correlated with a dynamical measure of metastability, and that the metastable phase persists to thermodynamic conditions previously thought of as unstable.