ANALYTICAL AND COMPUTATIONAL STUDY OF MAGNETIZATION SWITCHING IN KINETIC ISING SYSTEMS WITH DEMAGNETIZING FIELDS

摘要: An important aspect of real ferromagnetic particles is the demagnetizing field resulting from magnetostatic dipole-dipole interactions, which causes large to break up into equilibrium domains. Sufficiently small particles, however, remain single domain in equilibrium. This makes them particularly promising as materials for high-density magnetic recording media. In this paper we use analytic arguments and Monte Carlo simulations quantitatively study effects on dynamics magnetization switching two-dimensional, single-domain, kinetic Ising systems. For systems weak-field {open_quote}{open_quote}stochastic region,{close_quote}{close_quote} where average effected by nucleation growth a droplet, simulation results can be explained simple model free energy function only magnetization. intermediate-field {open_quote}{open_quote}multidroplet generalization Avrami{close_quote}s law involving magnetization-dependent effective gives good agreement with simulations. The do not qualitatively change droplet-theoretical picture highly anisotropic, single-domain grains, recently proposed [J. Magn. Mater. {bold 150}, 37 (1995)]. {copyright} {ital 1996 American Physical Society.}