International Business Machines Corporation

Kenneth E Johnson

David A Edmonson

Peter R Ivett

James J Mayerle

Seyyed M Mirzamaani

Arthur Carl Wall

James F Ward, Jr

Richard E Nelson

In a rigid magnetic recording disk, the magnetic properties, such as the coercivity, of a cobalt based, hard, magnetic alloy, such as a cobalt-platinum-chromium (CoPtCr) thin film magnetic recording layer, are controlled by providing a thin, sputtered, underlayer of a nonmagnetic, binary, chromium-tungsten (CrW) alloy whose major constituent is chromium, and preferably of a composition Cr.sub.88 W.sub.12 upon which the thin film magnetic recording layer is subsequently sputter deposited.

Magnetic recording medium having a cobalt-plantinum-chromium alloy

The magnetic properties of a cobalt based, thin film, magnetic recording layer are controlled, independent of controlling the process for depositing the magnetic layer itself, by the introduction of process compatible dopant gases into an argon atmosphere during the vacuum deposition (i.e. a sputtering process or an evaporation process) of a chromium based underlayer upon which the magnetic layer is subsequently deposited. The same or a different dopant may also be introduced into the magnetic layer. The process compatible dopant gases described contain oxygen, nitrogen and/or carbon, and mixtures thereof, and include the group purified air, oxygen, nitrogen, a mixture of oxygen and nitrogen, carbon monoxide, carbon dioxide, methane and water vapor.

Underlayer doping in thin film magnetic recording media

A fabrication method and structure for a cobalt alloy thin film magnetic recording media uses an underlayer of sputter deposited chromium having a thickness of 50 to 200 angstroms which presents the (100) plane of the chromium atoms at the surface upon which the cobalt alloy magnetic thin film layer is to be deposited. The cobalt alloy hexagonal close packed atomic structure is sputtered onto the chromium underlayer and epitaxially grown such that the (110) plane of the cobalt alloy structure is parallel to the media surface. This disposes the cobalt magnetic layer structure to have the C axis (easiest axis of the magnetization) parallel to the media surface to optimize horizontal recording density.

Thin film magentic media

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Rochester, MN, United States of America

Kenneth E Johnson