Title :
Exchange-coupled CoZrNb/CoSm underlayer for perpendicular recording media
Author :
Ando, Toshio ; Nishihara, Toshikazu
Author_Institution :
Victor Co. of Japan Ltd., Yokohama, Japan
fDate :
7/1/2001 12:00:00 AM
Abstract :
The characteristics and effects of an exchange-coupled CoZrNb/CoSm underlayer for perpendicular recording media are reviewed. A CoSm layer pins CoZrNb domains via exchange coupling resulting from large induced radial anisotropy of the CoSm layer in the disk medium as well as in the CoZrNb layer. The number of CoZrNb domain walls is considerably reduced by the CoSm pinning effect which is effective in both signal stabilization to stray fields and noise reduction. Furthermore, the CoZrNb/CoSm underlayers exhibit high-frequency responses of over 1 GHz in permeability, which also result from their large induced anisotropy. The CoZrNb/CoSm underlayer is expected to enable the practical realization of perpendicular recording in data storage applications requiring high densities and high-speed data rates
Keywords :
cobalt alloys; exchange interactions (electron); ferromagnetic materials; frequency response; induced anisotropy (magnetic); magnetic domain walls; magnetic hysteresis; magnetic permeability; magnetic recording noise; magnetic thin films; niobium alloys; perpendicular magnetic recording; samarium alloys; zirconium alloys; 0.1 to 3 GHz; CoZrNb domain walls; CoZrNb-CoSm; M-H loops; data storage applications; domain pinning; exchange coupling; exchange-coupled CoZrNb/CoSm underlayer; hard disks; high-frequency response; high-speed data rates; induced radial anisotropy; noise reduction; permeability; perpendicular recording media; stray field signal stabilization; Amorphous magnetic materials; Anisotropic magnetoresistance; Couplings; Disk recording; Magnetic anisotropy; Magnetic films; Permeability; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Soft magnetic materials;
Journal_Title :
Magnetics, IEEE Transactions on
