Magnetic recording media including a soft magnetic underlayer (SUL) formed over a plasma-polished substrate or pre-seed layer. In some examples, the substrate or pre-seed layer is plasma-polished using an inert gas such as krypton so that the roughness of the surface on which the SUL is deposited is reduced. The roughness reduction can lead to improved crystallographic texture within subsequently deposited media films, and consequently, to increased recording performance of the media. In particular, media signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a carbon deposition/etching apparatus may be modified to polish the substrate or pre-seed layer with krypton or other inert gases, rather than be used to deposit carbon overcoat.

Magnetic recording media including a soft magnetic underlayer (SUL) formed over a plasma-polished substrate or pre-seed layer. In some examples, the substrate or pre-seed layer is plasma-polished using an inert gas such as krypton so that the roughness of the surface on which the SUL is deposited is reduced. The roughness reduction can lead to improved crystallographic texture within subsequently deposited media films, and consequently, to increased recording performance of the media. In particular, media signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a carbon deposition/etching apparatus may be modified to polish the substrate or pre-seed layer with krypton or other inert gases, rather than be used to deposit carbon overcoat.

A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.

A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.

Various apparatuses, systems, methods, and media are disclosed to provide a magnetic recording medium with a tungsten (W) pre-seed layer. The W pre-seed layer has a higher conductance than a CrTi pre-seed layer with a similar thickness. In one embodiment, the W pre-seed layer is made of about 95 atomic percent or more of W. The W pre-seed layer has lower electrical resistivity than the CrTi pre-seed layer. As a result, the thickness of the W pre-seed layer can be reduced as compared to the thickness of a CrTi pre-seed layer if a similar conductance is to be achieved. The magnetic recording materials deposited on top of the W pre-seed layer with the reduced thickness provide comparable crystallographic orientation and recording performance to those deposited on top of a thicker CrTi pre-seed layer with a similar conductance.

Various apparatuses, systems, methods, and media are disclosed to provide a magnetic recording medium with a tungsten (W) pre-seed layer. The W pre-seed layer has a higher conductance than a CrTi pre-seed layer with a similar thickness. In one embodiment, the W pre-seed layer is made of about 95 atomic percent or more of W. The W pre-seed layer has lower electrical resistivity than the CrTi pre-seed layer. As a result, the thickness of the W pre-seed layer can be reduced as compared to the thickness of a CrTi pre-seed layer if a similar conductance is to be achieved. The magnetic recording materials deposited on top of the W pre-seed layer with the reduced thickness provide comparable crystallographic orientation and recording performance to those deposited on top of a thicker CrTi pre-seed layer with a similar conductance.

A method of manufacturing a magnetic recording medium including: forming a diffusion preventing layer, wherein the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein the perpendicular magnetic layer has a multi-layer structure, the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide, the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer, and the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component.

A method of manufacturing a magnetic recording medium including: forming a diffusion preventing layer, wherein the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein the perpendicular magnetic layer has a multi-layer structure, the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide, the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer, and the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component.

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.

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.