High density recording on SmCo/Cr thin film media

Author

Velu, E.M.T. ; Lambeth, D.N.

Author_Institution

Dept. of Electr. & Comput. Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA

Volume

28

Issue

5

fYear

1992

fDate

9/1/1992 12:00:00 AM

Firstpage

3249

Lastpage

3254

Abstract

SmCo/Cr thin films with coercivity up to 3000 Oe were prepared by RF-diode sputtering. Hard disks were fabricated using glass substrates and the recording properties, carrier-to-integrated-noise ratio, media noise, and overwritability were evaluated using conventional thin-film inductive heads. The influence of the thickness of the Cr underlayer, SmCo magnetic layer, and Cr overlayer on media noise was studied. The intergranular exchange and magnetostatic interaction effects present in SmCo/Cr media were measured from their remanence magnetization curves and correlated with media noise values obtained from recording measurements. The media noise in SmCo/Cr disks varied little with increasing linear density, and no supralinear increase in noise as explained by a transition noise model was observed. A thin Cr underlayer (<100 nm) gave the lowest noise SmCo media. An isolated pulse-to-integrated-noise ratio of 44 dB and an overwritability of better than 45 dB were obtained for SmCo/Cr hard disks

Keywords

chromium; cobalt alloys; exchange interactions (electron); ferromagnetic properties of substances; hard discs; magnetic recording; magnetic thin films; metallic thin films; remanence; samarium alloys; sputtered coatings; 100 nm; 44 dB; Cr; Cr overlayer; Cr underlayer; RF-diode sputtering; Sm-Co alloys; SmCo magnetic layer; SmCo-Cr; carrier-to-integrated-noise ratio; coercivity; glass substrates; hard disks; intergranular exchange; longitudinal thin film media; magnetostatic interaction effects; media noise; overwritability; recording measurements; recording properties; remanence magnetization curves; Chromium; Coercive force; Disk recording; Hard disks; Magnetic noise; Magnetic recording; Magnetostatics; Noise measurement; Sputtering; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.179774

Filename

179774