Effects of grain size and intergranular coupling on recording characteristics in CoCrTa media

Author

Sato, H. ; Nakai, J. ; Kikuchi, A. ; Mitsuya, H. ; Shimatsu, T. ; Takahashi, M.

Author_Institution

Kao Corp., Haga, Japan

Volume

32

Issue

5

fYear

1996

fDate

9/1/1996 12:00:00 AM

Firstpage

3596

Lastpage

3598

Abstract

The effects of grain size on intergranular magnetostatic coupling and on recording characteristics are discussed for the Co_85.5Cr_10.5Ta₄ and Co₇₈Cr ₁₇Ta₅ thin film media fabricated under the ultra clean sputtering process (UC-process). S/N_m increases not only with the increment in H_c/H_k^grain but also with the decrement in the grain diameter in both CoCrTa media. In media with high H_c/H_k^grain value more than 0.35, S/N_m drastically increases with decrease in the grain diameter, which corresponds to the decrease in the dispersion of magnetic field strength from recorded bits. To maintain high Hc_c/H_k^grain value more than 0.35 even in media with small grain size below 10 nm, the selection of alloy composition which gives a small 4πM_s/H_k^grain value of less than 1.0 is required

Keywords

chromium alloys; cobalt alloys; exchange interactions (electron); ferromagnetic materials; grain size; magnetic recording; magnetic recording noise; magnetic thin films; sputtered coatings; tantalum alloys; 10 nm; Co₇₈Cr₁₇Ta₅; Co_85.5Cr_10.5Ta₄; CoCrTa media; alloy composition; grain diameter; grain size; intergranular coupling; intergranular magnetostatic coupling; magnetic field strength dispersion; recorded bits; recording characteristics; thin film media; ultra clean sputtering process; Coercive force; Couplings; Disk recording; Dry etching; Fabrication; Grain size; Magnetic force microscopy; Magnetic noise; Signal to noise ratio; Silicon compounds;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.538701

Filename

538701