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

Volume

39

Issue

5

fYear

2003

Firstpage

2285

Lastpage

2287

Abstract

Fe-Co-B thin films with a high-saturation magnetization 4πM_s 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 H_c from 43 to 1 Oe and in increasing the in-plane uniaxial magnetic anisotropy, H_k to ∼330 Oe. In the Fe-Co-B(200 nm)/Ni-Fe(10 nm) double layer, no domain wall was observed. The high H_k led to a high ferromagnetic resonance frequency f_r 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; Fe_64.6Co_30.8B_4.6; Fe_64.6Co_30.8B_4.6-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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2003.816273

Filename

1233050