boron alloys; coercive force; ferromagnetic materials; iron alloys; Kerr magneto-optical effect; magnetic anisotropy; magnetic annealing, magnetic domains; nanostructured materials; niobium alloys; soft magnetic materials
Résumé :
[en] The magnetic domains of nanocrystalline Fe84Nb6B10 annealed under static and rotating magnetic fields have been investigated by means of magneto-optical Kerr effect (MOKE) microscopy in order to clarify the origin of the dramatic magnetic softening brought about by rotating field annealing. The coercivity (Hc) values after static- and rotating-magnetic field annealings are 5.9 and 3.0 A/m, respectively. The MOKE image after static field annealing implies a highly coherent uniaxial anisotropy (Ku) in the sample whereas no sign of such a strong Ku is evident in the domain configuration after rotating field annealing. Our analytical solution of the random anisotropy model with additional Ku predicts that the fluctuating amplitude of the effective anisotropy (δK) in nanocrystalline Fe84Nb6B10 decreases from 20 to 11 J/m3 by removing Ku. The observed reduction of Hc may be attributed to this decrease in δK induced by rotating field annealing.
Disciplines :
Physique
Identifiants :
UNILU:UL-ARTICLE-2010-481
Auteur, co-auteur :
Suzuki, K.; Department of Materials Engineering, Monash University, Clayton, Australia
Ito, N.
Saranu, S.
Herr, U.
MICHELS, Andreas ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Garitaonandia, J. S.
Langue du document :
Anglais
Titre :
Magnetic domains and annealing-induced magnetic anisotropy in nanocrystalline soft magnetic materials
Date de publication/diffusion :
2008
Titre du périodique :
Journal of Applied Physics
ISSN :
0021-8979
Maison d'édition :
American Institute of Physics, Melville, Etats-Unis - New York
