Role of geometrical symmetry in thermally activated processes in clusters of interacting dipolar moments

Article

关键词: MAGNETIC NANOPARTICLES;    LANGEVIN-DYNAMICS;    PARTICLE ASSEMBLIES;    RELAXATION;    TIME;    FLUCTUATIONS;    BEHAVIOR;    SYSTEMS;    ARRAYS;    ENERGY;   

DOI  :  10.1103/PhysRevB.89.104410

来源: SCIE

【 摘 要 】

Thermally activated magnetization decay is studied in ensembles of clusters of interacting dipolar moments by applying themaster-equation formalism, as a model of thermal relaxation in systems of interacting single-domain ferromagnetic particles. Solving the associated master equation reveals a breakdown of the energy barrier picture depending on the geometrical symmetry of structures. Deviations are most pronounced for reduced symmetry and result in a strong interaction dependence of relaxation rates on the memory of system initialization. A simple two-state system description of an ensemble of clusters is developed, which accounts for the observed anomalies. These results follow from a semianalytical treatment, and are fully supported by kinetic Monte Carlo simulations.

【 授权许可】

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