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】
Free