Precessional and thermal relaxation dynamics of magnetic nanoparticles: A time-quantified Monte Carlo approach

Abstract

A hybrid Monte Carlo (MC) method is proposed to study the full magnetization dynamics of a magnetic nanoparticle, comprising damping, thermal fluctuations, and precessional motion involved in a magnetization reversal process. The precessional motion is an athermal process, and has been neglected in previous MC schemes used to model magnetization dynamics. We introduce it into our hybrid method by adding a precessional step of the appropriate size to the random walk of the heat-bath Metropolis MC method. This hybrid MC method is applied for the study of the role of precession in the magnetization switching process of a magnetic nanoparticle under the influence of an oblique field. We numerically predict two distinct behaviors in the switching process corresponding to the high and low damping limits.