Title :
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
fDate :
9/1/1996 12:00:00 AM
Abstract :
The effects of grain size on intergranular magnetostatic coupling and on recording characteristics are discussed for the Co85.5Cr10.5Ta4 and Co78Cr 17Ta5 thin film media fabricated under the ultra clean sputtering process (UC-process). S/Nm increases not only with the increment in Hc/Hkgrain but also with the decrement in the grain diameter in both CoCrTa media. In media with high Hc/Hkgrain value more than 0.35, S/Nm 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 Hcc /Hkgrain value more than 0.35 even in media with small grain size below 10 nm, the selection of alloy composition which gives a small 4πMs/Hkgrain 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; Co85.5Cr10.5Ta4; 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;
Journal_Title :
Magnetics, IEEE Transactions on
