Computational and experimental results of thermally induced magnetization reversal in single-domain magnetic nanoparticles are reported. The simulations are based on direct integration of the Fokker-Planck equation that governs the dynamics of the magnetic moment associated with the nanoparticles. A mean-field approximation is used to account for the influence of the dipolar interaction between nanoparticles. It is shown that the interactions can either speed up or slow down the reversal process, depending on the angle between the external magnetic field and the axis of easy magnetization. The numerical results are in good agreement with experimental measurements of cobalt-platinum nanoparticles.

• Received 23 September 2011

DOI:https://doi.org/10.1103/PhysRevB.84.172407