Title :
Correlation between activation volume and intergranular magnetic interaction in longitudinal media
Author :
Mikami, M. ; Djayaprawira, D.D. ; Kong, T.K. ; Yoshimura, S. ; Horii, A. ; Takahashi, M.
Author_Institution :
Dept. of Electron. Eng., Tohoku Univ., Sendai, Japan
fDate :
7/1/2001 12:00:00 AM
Abstract :
We have investigated the correlation between the activation grain diameter derived from activation volume and the intergranular magnetic interaction, in CoCrPt-based thin film media fabricated by an ultra clean sputtering process. We found that the activation grain diameter depends on the physical grain diameter and intergranular exchange interaction, but is independent of intergranular magnetostatic interaction (4πMs/Hkgrain). The activation grain diameter normalized by the physical grain diameter, which corresponds with the normalized coercivity (Hc/Hk grain) and microstructure, indicate the character of the intergranular exchange interaction in the media with various compositions. It is also clarified that the media noise can be characterized by the activation grain diameter together with the intergranular magnetostatic interaction
Keywords :
chromium alloys; cobalt alloys; coercive force; exchange interactions (electron); ferromagnetic materials; grain size; magnetic recording noise; magnetic thin films; platinum alloys; sputtered coatings; CoCrPt; CoCrPt-based thin film media; activation grain diameter; activation volume; intergranular exchange interaction; intergranular magnetic interaction; intergranular magnetostatic interaction; longitudinal media; media noise; microstructure; normalized coercivity; ultra clean sputtering; Coercive force; Elementary particle exchange interactions; Magnetic anisotropy; Magnetic films; Magnetization; Magnetostatics; Microstructure; Perpendicular magnetic anisotropy; Sputtering; Substrates;
Journal_Title :
Magnetics, IEEE Transactions on
