CoCrPtTa and Co/Pd perpendicular magnetic recording media with amorphous underlayers

Author

Onoue, T. ; Asahi, T. ; Kuramochi, K. ; Kawaji, J. ; Homma, T. ; Osaka, T.

Author_Institution

Dept. of Appl. Chem., Waseda Univ., Tokyo, Japan

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

1592

Lastpage

1594

Abstract

The effect of amorphous carbon underlayers on magnetic properties and read-write characteristics of Co₇₃Cr₁₈Pt₆Ta₃ single layer and Co/Pd multilayer perpendicular magnetic recording media were investigated. The increase in H_c and decrease in α, defined as 4π(dM/dH)_H=Hc, were observed by increasing the underlayer thickness for both Co ₇₃Cr₁₈Pt₆Ta₃ and Co/Pd media. The media with a low α value, suggesting a decrease in the exchange coupling, exhibited the higher coercivity and the improvement of S/N ratio. In read-write experiments, the improvement of S/N ratio for the Co/Pd media was achieved up to 400 kFRPI or even higher in the recording density by increasing carbon underlayer thickness, while that for the Co₇₃Cr₁₈Pt₆Ta₃ media was obtained up to ca. 250 kFRPI

Keywords

amorphous state; carbon; chromium alloys; cobalt; cobalt alloys; coercive force; exchange interactions (electron); magnetic recording noise; palladium; perpendicular magnetic recording; platinum alloys; tantalum alloys; thermal stability; Co; Co/Pd multilayer; Co₇₃Cr₁₈Pt₆Ta₃; Co₇₃Cr₁₈Pt₆Ta₃ single layer; Pd; amorphous C underlayers; coercivity; exchange coupling; magnetic properties; perpendicular magnetic recording media; read-write characteristics; read-write experiments; recording density; underlayer thickness; Amorphous materials; Chemistry; Chromium; Magnetic anisotropy; Magnetic films; Magnetic multilayers; Magnetic recording; Magnetic separation; Perpendicular magnetic anisotropy; Perpendicular magnetic recording;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.950910

Filename

950910