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Magnetic relaxation in a model of interacting nanoparticles in terms of microscopic energy barriers

2004/07/07 by Òscar Iglesias, Oscar Iglesias, Amilcar Labarta +1
Physics and Astronomy · #Magnetic properties of thin films #Quantum and electron transport phenomena #Theoretical and Computational Physics #cond-mat.mtrl-sci

paper · pdf · doi:10.1002/pssa.200405486

published as Phys. Stat. Sol. A, 201, 3329 (2004) · Contribution to SCM 2004 (2nd Seeheim Conference on Magnetism), to be published in Physica Status Solidi. 5 pages, 3 figures

arxiv created 2004/07/07 · openalex publication_date 2004/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Monte Carlo simulations are used to study the magnetic relaxation of a system of single domain particles with dipolar interactions modeled by a chain of Heisenberg classical spins. We show that the so-called T ln (t/τ0) method can be extended to interacting systems and how, from the computed master relaxation curves, the effective energy barrier distributions responsible for the relaxation can be obtained. A transition from a quasi-logarithmic to power-law behavior of the relaxation as the interaction strength is increased is found. By direct computation of the effective energy barriers of the system, we show that this is due to the appearance of an increasing number of small energy barriers caused by the reduction of the anisotropy energy barriers as the local dipolar fields increase. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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