Magnetic recording medium having a cobalt-plantinum-chromium alloy magnetic layer and a chromium-tungsten underlayer a specified underlayer thickness range

摘要

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 Cr88W12 upon which the thin film magnetic recording layer is subsequently sputter deposited.