Media noise reduction in Co-based longitudinal media with new Co co-precipitated NiP/Al substrate

Author

Yoshimura, S. ; Djayaprawira, D.D. ; Kong, Tham Kim ; Masuda, Y. ; Shoji, H. ; Takahashi, M.

Author_Institution

Dept. of Electron. Eng., Tohoku Univ., Sendai, Japan

Volume

36

Issue

5

fYear

2000

fDate

9/1/2000 12:00:00 AM

Firstpage

2363

Lastpage

2365

Abstract

To decrease the grain size and grain size distribution in longitudinal media, a small amount of oxygen exposure onto either normal NiP or Co co-precipitated Co-NiP/Al-alloy substrates has been used. The substrate surfaces of both media were dry-etched by RF-plasma prior to oxygen exposure. The exposure of 3.5 L of oxygen onto the normal NiP substrate surface reduces the grain diameter from 10.0 nm to 8.8 nm while maintaining the standard distribution of grain diameter of about 1.4 nm. As a result, the media signal to noise ratio increases by 0.6 dB. By adding 400 ppm of Co into NiP plated substrate and combined with 1.5 L of oxygen exposure, the grain diameter and the standard distribution of grain diameter decrease from 9.2 nm to 8.3 nm. As a result, the media signal to noise ratio increases by 1.0 dB

Keywords

aluminium; cobalt alloys; grain size; magnetic recording noise; magnetic thin films; nickel compounds; sputter etching; substrates; Al; Co co-precipitated NiP/Al substrate; Co-based longitudinal media; CoCrTaNiPt; Cr; NiP; RF-plasma; dry-etching; grain diameter; grain size; media noise reduction; oxygen exposure; signal to noise ratio; substrate surfaces; Chromium; Coercive force; Crystallography; Grain size; Noise reduction; Oxygen; Signal to noise ratio; Sputtering; Substrates; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.908431

Filename

908431