Abstract: 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.

Abstract: 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.