Grace Lim

US Patent:

46542760, Mar 31, 1987

Filed:

Apr 29, 1986

Appl. No.:

6/857019

Inventors:

Richard H. Ahlert - San Jose CA
James K. Howard - Morgan Hill CA
Grace S. Lim - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B32B 1500

US Classification:

428641

Abstract:

An improved cobalt-platinum (CoPt) thin film metal alloy media for horizontal magnetic recording has a coercivity substantially greater than prior CoPt thin film metal alloy media. A tungsten underlayer between the substrate and the CoPt magnetic layer improves the coercivity above that of media wiht conventional underlayers, such as chromium. The coercivity of the CoPt layer can be increased even further if the CoPt film is deposited in such a manner as to form an intermetallic compound of Co. sub. 3 W in the interface region between the tungsten underlayer and the CoPt magnetic layer. The tungsten underlayer also improves the magnetic properties of the media when the magnetic layer is an alloy of cobalt-platinum-chromium (CoPtCr).

US Patent:

47496282, Jun 7, 1988

Filed:

Apr 29, 1986

Appl. No.:

6/857206

Inventors:

Richard H. Ahlert - San Jose CA
James K. Howard - Morgan Hill CA
Grace S. Lim - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01F 1016
H01F 1030

US Classification:

428660

Abstract:

A vertical magnetic recording medium is formed of multiple layers, each layer comprising a cobalt-platinum (CoPt) magnetic film formed on a hexagonal-close-packed (HCP) necleating film. The thickness of each CoPt film in each layer is sufficiently thin to assure that the film has perpendicular magnetic anisotropy. The magnetic properties of the multilayered magnetic film structure can be varied by varying the thickness of the individual films and the number of layers.