Influence of surface anisotropy on the hysteresis of magnetic nanoparticles

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:290

Article; Proceedings Paper

Iglesias, O ; Labarta, A

关键词: anisotropy surface;    Monte Carlo simulation;    nanoparticles;   

DOI  :  10.1016/j.jmmm.2004.11.358

来源: Elsevier

【 摘 要 】

We present the results of Monte Carlo simulations of the magnetic properties of individual spherical nanoparticles with the aim of explaining the role played by surface anisotropy on their low-temperature magnetization processes. Phase diagrams for the equilibrium configurations have been obtained, showing a change from quasi-uniform magnetization state to a state with hedgehog-like structures at the surface as k(S), the surface anisotropy constant, increases. Through the simulated hysteresis loops and the analysis of spin configurations along them, we have identified a change in the magnetization reversal mechanism from quasi-uniform rotation at low k(S) values, to a non-uniform switching process at high k(S). Results for the dependence of the coercive field and remanence on k(S) and particle size are also reported. (c) 2004 Elsevier B.V. All rights reserved.

【 授权许可】

Free