1. Time quantification for Monte Carlo modeling of superparamagnetic relaxation
- Author
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V. V. Rusakov, Régine Perzynski, P. V. Melenev, and Yu. L. Raikher
- Subjects
Physics ,Magnetic moment ,Field (physics) ,Monte Carlo method ,Relaxation (physics) ,Non-equilibrium thermodynamics ,Particle ,Statistical physics ,Condensed Matter Physics ,Anisotropy ,Electronic, Optical and Magnetic Materials ,Superparamagnetism - Abstract
Monte Carlo modeling of superparamagnetic kinetics is addressed with regard to quantification of the simulation steps in units of real time. For the classical N\'eel case (field-free relaxation of the magnetic moment in a single-domain uniaxial particle), a modification of the Nowak-Chantrell-Kennedy formula is proposed enabling the calculations with the variation amplitude of the magnetic moment independent of the particle anisotropy. This relation is obtained from comparison of the Monte Carlo simulated relaxation against the solution of the kinetic equation for the particle magnetic moment. The same idea is applied to a strongly nonequilibrium process: steady re-magnetization of a superparamagnetic particle under an ac field. It is found that in the latter case a linear relationship can be established between the number of simulation steps and the real-time scale (the field period) that holds fairly well in wide frequency and anisotropy parameter intervals.
- Published
- 2012