Magnetic recording medium for e.g hard disk, has a thin, low rate deposited cobalt alloy nucleation layer

摘要

A magnetic recording medium has an extremely thin, low rate deposited cobalt alloy nucleation layer between a chromium under layer and a cobalt-platinum alloy magnetic layer. A magnetic recording medium is produced by successively applying chromium, cobalt alloy and cobalt-platinum alloy layers onto a substrate, the novelty being that (a) the chromium layer is applied under equilibrium or near equilibrium crystal growth conditions; (b) the cobalt alloy layer is applied at less than 1 Angstrom /sec.; (c) the chromium layer is applied to <= 20 Angstrom thickness; or (d) the chromium layer is applied using a target cathode current density of <= 1.0 W/cm<2>. Independent claims are also included for the following: (i) a magnetic recording medium having a sequence of a <= 20 Angstrom thick chromium layer, a cobalt alloy layer and a cobalt-platinum alloy layer; (ii) a magnetic recording medium having a sequence of chromium, cobalt alloy and cobalt-platinum alloy layers, the chromium layer being applied under equilibrium or near equilibrium crystal growth conditions; and (iii) disk drives comprising the above magnetic recording media. Preferred Features: The low deposition rate is achieved by h.f. sputter deposition with a d.c. substrate bias.