Thin-film media with compositional gradient for high-density recording

Author

Lal, Brij B. ; Shinohara, T.

Author_Institution

IBM Technol., Fremont, CA, USA

Volume

29

Issue

6

fYear

1993

fDate

11/1/1993 12:00:00 AM

Firstpage

3712

Lastpage

3714

Abstract

A sputtering technique for mixing two or more magnetic alloys has been developed. This technique produces magnetic compositional-gradient along film thickness. CoNiCr and CoCrTa-magnetic alloys were used for this sputtering scheme. In one case, the low-noise characteristics of the first magnetic layer-CoCrTa with Ms:659 emu/cc is combined with the high Br, remanence magnetization characteristics of the second magnetic layer-CoNiCr with Ms:1110 EMU/CC. The performance of CoNiCr/CoCrTa-gradient media was better than the CoCrTa/CoNiCr-gradient media. Magnetic and recording properties of the gradient thin-film media were compared with the single-layer media of CoNiCr and CoCrTa. The coercivity of gradient media was about 20% higher than their single-layer media. The remanence magnetization of gradient-media is about 25-30% higher than the CoCrTa-single layer media. Also, CoNiCr/CoCrTa-compositional gradient media produce about 40% lower media-noise in comparison to CoNiCr-single layer media

Keywords

chromium alloys; cobalt alloys; coercive force; ferromagnetic properties of substances; magnetic multilayers; magnetic recording; nickel alloys; noise; remanence; sputter deposition; tantalum alloys; CoCrTa; CoCrTa-CoNiCr; CoCrTa/CoNiCr-gradient media; CoNiCr; CoNiCr-CoCrTa; CoNiCr/CoCrTa-gradient media; TEM micrographs; coercivity; gradient thin-film media; high-density recording; low-noise characteristics; magnetic compositional-gradient; performance; recording properties; remanence magnetization characteristics; sputtering technique; Coercive force; Magnetic films; Magnetic noise; Magnetic properties; Magnetic recording; Magnetic separation; Magnetization; Remanence; Sputtering; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.281278

Filename

281278