Details

Autor(en) / Beteiligte

• Yan, M.L.
• Skomski, R.
• Kashyap, A.
• Gao, L.
• Liou, S.H.
• Sellmyer, D.J.

Titel

Hysteresis of granular FePt:Ag films with perpendicular anisotropy

Ist Teil von

• IEEE transactions on magnetics, 2004-07, Vol.40 (4), p.2495-2497

Ort / Verlag

New York, NY: IEEE

Erscheinungsjahr

2004

Quelle

IEEE Xplore

Beschreibungen/Notizen

• Intergranular interactions in nanostructured FePt:Ag thin films and their effect on magnetic hysteresis are investigated. The films, produced by multilayer deposition plus rapid thermal annealing, consist of FePt nanoparticles embedded in a silver matrix. They are investigated by magnetization measurements and magnetic force microscopy. Analytical model calculations, supported by micromagnetic simulations, are used to elucidate the relation between coercivity, hysteresis-loop slope, and spatial correlations during magnetization reversal. The analytical calculations yield simple expressions for the loop slope and the coercivity as a function of the intergranular exchange. Small intergranular exchange enhances the coercivity, but for strong exchange there is a self-energy cutoff, associated with the onset of cooperative reversal and preventing alpha from becoming negative.