Title :
Fe-Co-B/Ni-Fe soft magnetic underlayer with high-saturation magnetization for perpendicular magnetic recording media
Author :
Kong, S.H. ; Okamoto, T. ; Nakagawa, S.
Author_Institution :
Tokyo Inst. of Technol., Japan
Abstract :
Fe-Co-B thin films with a high-saturation magnetization 4πMs of ∼23 kG were investigated for use as the soft magnetic underlayer in perpendicular magnetic recording media. In order to improve the soft magnetic properties of a Fe-Co-B layer, A Ni-Fe underlayer was examined. The Ni-Fe underlayer was effective in reducing the coercivity Hc from 43 to 1 Oe and in increasing the in-plane uniaxial magnetic anisotropy, Hk to ∼330 Oe. In the Fe-Co-B(200 nm)/Ni-Fe(10 nm) double layer, no domain wall was observed. The high Hk led to a high ferromagnetic resonance frequency fr above 3 GHz in the Fe-Co-B/Ni-Fe double layer.
Keywords :
boron alloys; cobalt alloys; coercive force; ferromagnetic materials; ferromagnetic resonance; iron alloys; magnetic anisotropy; magnetic domain walls; magnetic thin films; magnetisation; nickel alloys; perpendicular magnetic recording; soft magnetic materials; 10 nm; 200 nm; 23 kG; 3 GHz; Fe-Co-B thin films; Fe-Co-B/Ni-Fe soft magnetic underlayer; Fe64.6Co30.8B4.6; Fe64.6Co30.8B4.6-Ni79Fe21; Fe70Co30; FeCoB-NiFe; coercivity; domain wall; double layer; high ferromagnetic resonance frequency; high-saturation magnetization; in-plane uniaxial magnetic anisotropy; perpendicular magnetic recording media; Coercive force; Magnetic anisotropy; Magnetic domain walls; Magnetic films; Magnetic properties; Magnetic resonance; Magnetization; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Soft magnetic materials;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.816273
