Various embodiments provide for a heat assisted magnetic recording (HAMR) media comprising: a magnetic recording layer; a barrier layer disposed under the magnetic recording layer; a first underlayer disposed under the barrier layer; and an amorphous seedlayer disposed under the first underlayer. For some embodiments, the recording medium may comprise: a magnetic recording layer including FePt alloy, a CoPt alloy, or a FePd alloy; a barrier layer including MgO, TiC, TiN, CrN, TiCN, β-WC, TaC, HfC, ZrC, VC, NbC, or NiO; a first underlayer including RuAl-oxide, NiAl, FeAl, AlMn, CuBe, or AlRe; or an amorphous seedlayer including a Cr—X alloy, where X comprises Al, B, C, Cu, Hf, Ho, Mn, Mo, Ni, Ta, Ti, V, W, or Ru.

Underlayers for heat assisted magnetic recording (HAMR) media

A perpendicular magnetic recording medium comprises a magnetic recording layer that records a signal, an underlayer formed of Ru or Ru compound below the magnetic recording layer, a non-magnetic layer formed of a non-magnetic material below the underlayer to control crystal orientation of the underlayer, a soft magnetic layer provided below the non-magnetic layer, and a substrate on which the magnetic recording layer, the underlayer, the non-magnetic layer, and the soft magnetic layer are formed. The non-magnetic layer comprises a first non-magnetic layer formed above the soft magnetic layer and a second non-magnetic layer formed above the first non-magnetic layer. The first non-magnetic layer is formed of amorphous Ni compound while the second non-magnetic layer is formed of crystalline Ni or crystalline Ni compound.

Perpendicular magnetic recording medium and method of manufacturing the same

An object of the present invention is to provide a perpendicular magnetic recording medium in which each space between crystal grains of a first magnetic recording layer is so designed as to allow the layer to also have a function as a continuous layer, and a method of manufacturing a perpendicular magnetic recording medium. In a perpendicular magnetic recording medium 100 according to the present invention, a first magnetic recording layer 122 a and a second magnetic recording layer 122 b are ferromagnetic layers each having a granular structure in which a grain boundary part made of a non-magnetic substance is formed between crystal grains each grown in a column shape and, in the first magnetic recording layer 122 a , an intergranular distance defined by an average of shortest distances between grain boundary parts each between a crystal grain and its adjacent crystal grain is equal to or shorter than 1 nm.

Perpendicular magnetic recording medium and process for manufacture thereof

Provided are a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer ( 20 ) which is formed on a disk substrate 10 directly or via an intermediate layer and which has non-magnetic regions between granular columnar particles; and an auxiliary recording layer ( 22 ) which is formed on the granular magnetic recording layer 20 and which causes exchange interaction among the granular columnar particles, wherein the auxiliary recording layer ( 22 ) contains 0.1 to 3 moles of oxygen.

Magnetic disk and method for manufacturing same

Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.

Magnetic disk and method of manufacturing the same

A disk for a hard disk drive is provided. The disk comprises a substrate comprising aluminum, and a coating layer disposed over the substrate. The coating layer comprises an alloy of Ni, X 1 and X 2 , wherein X 1 comprises one or more elements selected from the group consisting of Ag, Au, B, Cr, Cu, Ga, In, Mn, Mo, Nb, Pb, Sb, Se, Sn, Te, W, Zn and Zr, and wherein X 2 comprises either B or P, and wherein X 1 and X 2 do not comprise the same elements.

Electroless coated disks for high temperature applications and methods of making the same

An aqueous electroless nickel-phosphorous plating bath for forming an electroless nickel-phosphorous coating on an alkaline zincate coated substrate includes about 1.0 g/l to less than 5.0 g/l Ni, about 25 g/l to about 40 g/l hypophosphorous reducing agent; and 0 to about 120 g/l orthophosphite by-product. The electroless nickel-phosphorous bath with an orthophosphite concentration of up to about 120 g/l provides an electroless nickel-phosphorous deposit on the zincate coated substrate with an intrinsic stress that is more compressive than electroless nickel-phosphorous deposit provided using conventional electroless nickel-phosphorous baths.

Alan J. Ruffini

Papers

Electroless coated disks for high temperature applications and methods of making the same

Electroless nickel-phosphorous plating baths with reduced ion concentration and methods of use

Electroless nickel-phosphorous plating method using baths with reduced ion concentration