Patent ID: 6517956
Filing Date: 2003-02-11
Classification: G11B,Y10T

Abstract:
A magnetic recording medium having a dual layer protective overcoat over a magnetic layer, the dual layer protective overcoat comprising:a layer of aluminum nitride (AlN) over the magnetic layer; and a carbon-containing layer on the AlN layer, wherein the dual protective overcoat has a thickness of about 75 Ã¥ or less, the magnetic recording medium further comprising: a substrate comprising aluminum or an aluminum alloy, a glass, ceramic, glass-ceramic or polymeric material, or a metal-plastic composite, the substrate having a nickel-phosphorous plating thereon; a seedlayer on the substrate, the seedlayer comprising nickel-aluminum (NiAl) or oxidized NiAl; an intermediate layer on the seedlayer, the intermediate layer comprising chromium (Cr) or an Cr alloy; an underlayer on the intermediate layer, the underlayer comprising a Cr alloy; a non-magnetic grain epitaxy layer on the underlayer, the non-magnetic grains expitaxy layer comprising a cobalt-chromiumn alloy; a first magnetic layer on the non-magnetic grain epitaxy layer, the first magnetic layer comprising a cobalt-chromium-tantalum alloy without platinum; a second magnetic layer comprising a cobalt-chromium-platinum alloy, wherein the dual layer protective overcoat is on the second magnetic layer; and a lubricant topcoat on the dual layer protective overcoat.