Presented at 1997 March Meeting of the American Physical Society.
Simulations involving kinetic Ising models have been used to make theoretical predictions for the switching in single-grain single-domain ferromagnets.1 Droplet theory has been quite successful in explaining simulation results for the d=2 kinetic Ising model.1 To compare these predictions in d=3 we have performed large scale Monte Carlo simulations of a cubic nearest-neighbor kinetic Ising model. The simulation results include the lifetime of the metastable state, the system size dependence of the switching field for a given waiting time, and the time dependence of the magnetization. In particular, we compare with predictions due to Avrami's law for simultaneous nucleation and growth of droplets. Our d=3 simulations confirm droplet theory predictions while demonstrating some important effects which did not appear to be as significant in the d=2 work.
1H.L. Richards, S.W. Sides, M.A. Novotny, and P.A. Rikvold, J. Magn. Magn. Mater. 150, 37 (1995); J. Appl. Phys. 79, 5479 (1996).