Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/10916
Title: Magnetic relaxation in terms of microscopic energy barriers in a model of dipolar interacting nanoparticles
Author: Iglesias, Òscar
Labarta, Amílcar
Keywords: Relaxació magnètica
Mètode de Montecarlo
Histèresi
Nanopartícules
Magnetic relaxation
Monte Carlo method
Hysteresis
Nanoparticles
Issue Date: 2004
Publisher: The American Physical Society
Abstract: The magnetic relaxation and hysteresis of a system of single domain particles with dipolar interactions are studied by Monte Carlo simulations. We model the system by a chain of Heisenberg classical spins with randomly oriented easy-axis and log-normal distribution of anisotropy constants interacting through dipole-dipole interactions. Extending the so-called $T\ln(t/\tau_0)$ method to interacting systems, we show how to relate the simulated relaxation curves to the effective energy barrier distributions responsible for the long-time relaxation. We find that the relaxation law changes from quasi-logarithmic to power-law when increasing the interaction strength. This fact is shown to be due to the appearence of an increasing number of small energy barriers caused by the reduction of the anisotropy energy barriers as the local dipolar fields increase.
Note: Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevB.70.144401
It is part of: Physical Review B, 2004, vol. 70, núm, 14, p. 144401-1-144401-10
Related resource: http://doi.org/10.1103/PhysRevB.70.144401
URI: http://hdl.handle.net/2445/10916
ISSN: 0163-1829
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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