Dipolar interaction effects on the thermally activated magnetic relaxation of two-dimensional nanoparticle ensembles

The thermally activated magnetic relaxation in two-dimensional lattices of dipolar interacting nanoparticles with large uniaxial perpendicular anisotropy is studied by a numerical method and within the mean-field approximation for comparison. The role that the correlation effects play in magnetic relaxation and the influence of lattice structure and bias magnetic field on the relaxation process are revealed. The correlations of the nanoparticle magnetic moments enhance relaxation on small times, delay it on large times, and reduce the steady-state absolute magnetization at nonzero bias fields. In a hexagonal lattice, magnetic relaxation on small times occurs faster and the steady-state absolute magnetization has the larger magnitude than in a square lattice with the same lattice spacing. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/262