Exchange coupling mechanism for magnetization reversal and thermal stability of Co nanoparticles embedded in a CoO matrix

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:294

Article; Proceedings Paper

Givord, D ; Skumryev, V ; Nogués, J

关键词: superparamagnetism;    exchange bias;    magnetic nanoparticles;    antiferromagnets;   

DOI  :  10.1016/j.jmmm.2005.03.022

来源: Elsevier

【 摘 要 】

A model providing a semi-quantitative account of the magnetic behavior of Co nanoparticles embedded in a CoO matrix is presented. The results confirm that exchange coupling at the interface between ferromagnetic (FNI) and antiferromagnetic (AFM) nanostructures could provide an extra source of magnetic anisotropy, leading to thermal stability of the FM nanoparticles. It is shown that perpendicular coupling between the AFM and FM moments may result in large coercivities. The energy barrier, which works against reversal is due to the AFM susceptibility anisotropy. The experimentally observed exchange bias is tentatively ascribed to pre-existing intrinsic canting of the AFM moments at the interface. (c) 2005 Elsevier B.V. All rights reserved.

【 授权许可】

Free