Role of surface disorder on the magnetic properties and hysteresis of nanoparticles

Abstract

We present the results of Monte Carlo simulations of a model of a single maghemite ferrimagnetic nanoparticle including radial surface anisotropy distinct from that in the core with the aim to clarify what is its role on the magnetization processes at low temperatures. The low temperature equilibrium states are analized and compared to those of a ferromagnetic particle with the same lattice structure. We have found that the formation of hedgehog-like structures due to increased surface anisotropy is responsible for a change in the reversal mechanism of the particles.

arXiv comment9 pages,4 eps +1 gif figures. Presented at HMM 2003, Salamanca (Spain), to be published in Physica B. Animated snapshots of configurations along the hysteresis loops may be found at http://hermes.ffn.ub.es/oscar/Simulations/Simulations.html

References in corpus (3)

• Finite-Size and surface effects in maghemite nanoparticles: Monte Carlo simulations
• Surface effects in nanoparticles: application to maghemite $\gamma$-Fe_{2}O_{3}
• Monte Carlo Study of the Finite Size Effects on the Magnetization of Maghemite Small Particles

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