A method for making a magnetic recording tape, in accordance with one approach, includes coupling an underlayer to a substrate, the substrate comprising a poly ether ether ketone (PEEK). A method for making a magnetic recording tape in accordance with another approach includes coupling an underlayer to a substrate via radiation-induced grafting, the substrate comprising a poly ether ether ketone (PEEK). A recording layer may be coupled to the underlayer.

Magnetic media including a magnetic recording layer structure formed of alternating magnetic recording sublayers and non-magnetic exchange control sublayers. The magnetic recording layer structure may include at least one magnetic recording sublayer formed to include a pair of thin films, with the films having different concentrations of platinum, ruthenium, and/or oxide segregants. That is, the sublayer has a “dual layer” structure. The dual layer structure can provide a gradient in magnetic anisotropy, saturation magnetization, and/or intergranular magnetic exchange coupling across the sublayer. In some examples, the film nearer to the substrate of the magnetic media has a higher platinum concentration than the other film. In one aspect, the magnetic media includes the substrate and the magnetic recording layer structure on the substrate, with the structure including six magnetic recording sublayers. In another aspect, a method of fabricating magnetic media with such structures is provided.

Methods of forming a layer of magnetic material on a substrate, the method including: configuring a substrate in a chamber; controlling the temperature of the substrate at a substrate temperature, the substrate temperature being at or below about 250 C.; and introducing one or more precursors into the chamber, the one or more precursors including: cobalt (Co), nickel (Ni), iron (Fe), or combinations thereof, wherein the precursors chemically decompose at the substrate temperature, and wherein a layer of magnetic material is formed on the substrate, the magnetic material including at least a portion of the one or more precursors, and the magnetic material having a magnetic flux density of at least about 1 Tesla (T).

A method of cleaning a substrate processing apparatus that etches a film including a metal includes (a) providing an inert gas, and removing a metal-containing deposition by plasma generated from the inert gas; and (b) after (a), providing a gas containing a fluorine-containing gas and an oxygen-containing gas, and removing a silicon-containing deposition by plasma generated from the gas containing the fluorine-containing gas and the oxygen-containing gas.

A magnetic disk substrate is composed of an aluminum alloy substrate, a base plating layer on a surface of the aluminum alloy substrate, and a boundary region between the aluminum alloy substrate and the base plating layer. The boundary region includes a specific boundary region (D(1).sub.I((50-84)) having A, emission intensities equal to 50% to 84% of an average Al emission intensity in an interior region of the aluminum alloy substrate in glow discharge optical emission spectroscopy in the depthwise direction from the surface of the magnetic disk substrate. The specific boundary region (D(1).sub.I(50-84)) has a maximum Fe emission intensity (I(1).sub.Fe(max)) higher than an average Fe emission intensity (I(1).sub.Fe(ave)) in the interior region of the aluminum alloy substrate in the glow discharge optical emission spectroscopy.

The purpose of the present invention is to provide a magnetic recording medium having a stacked structure of a seed layer including (Mg.sub.1-xTi.sub.x)O and a magnetic recording layer including an L1.sub.0 ordered alloy, and having improved properties. The method for producing a magnetic recording layer according to the present invention includes the steps of: (1) preparing a substrate; (2) forming a seed layer including (Mg.sub.1-xTi.sub.x)O onto the substrate; (3) plasma etching the seed layer in an atmosphere including inert gas; and (4) forming a magnetic recording layer including an ordered alloy onto the seed layer which has been subjected to the step (3).

A substrate processing method includes a first discharge step of discharging, from the first discharge port which faces a predetermined first region including the rotating center of the upper surface, a low surface tension liquid containing gas containing steam of a low surface tension liquid having a larger specific gravity than air and lower surface tension than the processing liquid and not discharging the low surface tension liquid containing gas from the second discharge port which faces a predetermined second region surrounding the outside of the first region on the upper surface of the substrate, and a second discharge step of discharging the low surface tension liquid containing gas from the second discharge port after the first discharge step and not discharging the low surface tension liquid containing gas from the first discharge port.

In one aspect, the present disclosure provides a method for producing an aluminum platter, which can improve the smoothness of the substrate surface before a magnetic layer is formed thereon and can provide a hard disk substrate that can be processed into a medium with a high yield. In another aspect, the present disclosure relates to a method for producing an aluminum platter, including the following steps 1 and 2: step 1: bringing a composition containing a compound (component A) that has at least one structure represented by the following formula (I) and has a molecular weight between 50 and 100,000 inclusive into contact with a substrate surface of a NiP plated aluminum alloy substrate; and step 2: forming a magnetic layer on the substrate obtained in the step 1.

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An aluminum alloy substrate (1) for magnetic disk satisfies at least two of three inequalities of an inequality group [A] and satisfies all of four inequalities of an inequality group [B], or satisfies at least two of the three inequalities of the inequality group [A] and satisfies all of four inequalities of an inequality group [C], when a plate thickness of the disk at a position (b1) is defined as t.sub.b1, a plate thickness at a position (b2) is defined as t.sub.b2, a plate thickness at a position (b3) is defined as t.sub.b3, a plate thickness at a position (a1) is defined as t.sub.a1, a plate thickness at a position (a2) is defined as t.sub.a2, and a plate thickness at a position (a3) is defined as t.sub.a3.

This aluminum alloy substrate for a magnetic recording medium has a metal structure made of an Al alloy having a composition including Si in a range of 18.0% by mass to 22.0% by mass, Fe in a range of 4.0% by mass to 6.0% by mass, Cu in a range of 2.5% by mass to 4.0% by mass, and Mg in a range of 0.8% by mass to 1.5% by mass with a remainder being Al, a primary-crystal Si precipitate having a maximum diameter of 0.5 m or more and an average particle diameter of 2 m or less is dispersed in the metal structure, a diameter is in a range of 53 mm to 97 mm, and a thickness is in a range of 0.2 mm to 0.9 mm.