Role of the magnetic anisotropy in the magnetocaloric effect for a superparamagnetic nanoparticle system: a Monte Carlo study

摘要

The magnetocaloric properties of a fine magnetic particle system are studied by means of a Monte Carlo technique, focusing on the role played by the magnetic anisotropy. By varying the anisotropy of the particles, keeping fixed their size and magnetization, we have found that for a fixed concentration the entropy grows for smaller values of the anisotropy. It is also observed that, when comparing different concentrations,rnthe entropy change for low anisotropy is larger at low concentrations, while for high anisotropy it follows the opposite trend. It is also observed that the blocking temperature increases with increasing values of the anisotropy, as it is expected with the enhancement of the anisotropy energy barriers of the particles.