Numerical stochastic model for the magnetic relaxation time of the fine particle system with dipolar interactions

摘要

This paper presents the results obtained by numerical simulations, the magnetic relaxation time simulation for a fine particle system with dipolar magnetic interaction. We used a 3D simulation model for fine magnetic particles with spherical shape and lognormal distribution for their diameters. Starting from Dormann-Bessais-Fiorani model, the 3D model we used is more realistic if we consider that the particles are randomly arranged into a preset volume, following a Gaussian distribution generated with the Box-Mueller transformation. Concerning the dependency of the average relaxation time on temperature and on the dispersion of the particle diameter's logarithm, the analysis is achieved for three cases: without interaction, weak dipolar magnetic interaction, and strong dipolar magnetic interaction between particles. We found that the average relaxation time for the fine particle system decreases by temperature's increasing and the average relaxation time grows by the growth of the dispersion of the random "ln d" variable.