MURPHYS-HSFS-2014 - 7th International Workshop on Multi-Rate Processes & Hysteresis, 2nd International Workshop on Hysteresis and Slow-Fast Systems, April 7-11, 2014 - Abstract
Hovorka, Ondrej
Thermally activated magnetization decay is studied in ensembles of clusters of spins by applying the formalism of theory of Markov processes, as a model of thermal relaxation in systems of interacting single-domain ferromagnetic nanoparticles. Solving the associated master-equation reveals the memory effect where the magnetization decay depends on the field history applied during the system initialization. The memory effect depends on the geometry of spin arrangement within clusters, being most pronounced for clusters with reduced symmetry and disappearing for symmetric clusters. These results follow from a semi-analytical treatment, and are fully supported by kinetic Monte-Carlo simulations.