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.

A magnetic recording medium includes a nonmagnetic substrate, a soft magnetic underlayer, an orientation control layer, a perpendicular magnetic layer, and a protection layer that are arranged in this order. The perpendicular magnetic layer includes a first magnetic layer and a second magnetic layer that are arranged in this order on the orientation control layer. The first magnetic layer has a granular structure including an oxide at grain boundary parts of magnetic grains, and the second magnetic layer is closest to the protection layer among layers within the perpendicular magnetic layer, and includes magnetic grains made of a CoCrPt alloy, and a nitride of carbon or a hydride of carbon.

To provide a magnetic recording tape and the like that have excellent magnetic properties and exhibit a favorable SNR. There are provided a magnetic recording tape and the like including at least: a base layer that includes a long film having flexibility; and a magnetic layer formed on a side of one main surface of the base layer, in which an under layer and a seed layer are provided in the stated order from a side of the magnetic layer toward a side of the base layer between the magnetic layer and the base layer, the underlayer contains at least Co and Cr, and has an average atomic number ratio represented by the following formula (1): Co.sub.(100-y)Cr.sub.y (where y is within a range of 37≤y≤45.), and the seed layer formed directly on the base layer has a film thickness of 5 nm or more and 30 nm or less, and contains Ti and O and has an average atomic number ratio represented by the following formula (2): Ti.sub.(100-x)O.sub.x (where x≤10.) or contains Ti—Cr—O and has an average atomic number ratio represented by the following formula (3): (TiCr).sub.(100-x)O.sub.x (where x≤10.).

A magnetic recording cartridge is provided and including a magnetic recording medium, wherein an average thickness of the magnetic recording medium t.sub.T is 3.5 μm≤t.sub.T≤5.6 μm, a dimensional change amount Δw in a width direction of the magnetic recording medium with respect to a tension change in a longitudinal direction of the magnetic recording medium is 700 ppm/N≤Δw≤20000 ppm, the magnetic recording medium is accommodated in a state of being wound around the reel in the cartridge case and (a servo track width on an inner side of winding of the magnetic recording medium)—(a servo track width on an outer side of winding of the magnetic recording medium)>0 is satisfied, and a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more.

A magnetic recording medium includes a nonmagnetic substrate, a soft magnetic underlayer, an orientation control layer, a perpendicular magnetic layer, and a protection layer that are arranged in this order. The perpendicular magnetic layer includes a first magnetic layer and a second magnetic layer that are arranged in this order on the orientation control layer. The first magnetic layer has a granular structure including an oxide at grain boundary parts of magnetic grains, and the second magnetic layer is closest to the protection layer among layers within the perpendicular magnetic layer, and includes magnetic grains made of a CoCrPt alloy, and a nitride of carbon or a hydride of carbon.

There is provided a magnetic recording medium that enables stable traveling upon recording processing and reproduction processing. The magnetic recording medium is a magnetic recording medium having a tape-like shape. The magnetic recording medium includes a substrate and a magnetic layer provided on the substrate. When a weight of the magnetic recording medium is set to one, a rate of a moisture content contained in the magnetic recording medium in a state of being stored in an environment of 23 C. and 45% RH for 24 hours or more is 0.64 wt % or less.

There is provided a magnetic recording medium that enables stable traveling upon recording processing and reproduction processing. The magnetic recording medium is a magnetic recording medium having a tape-like shape. The magnetic recording medium includes a substrate and a magnetic layer provided on the substrate. When a weight of the magnetic recording medium is set to one, a rate of a moisture content contained in the magnetic recording medium in a state of being stored in an environment of 23 C. and 45% RH for 24 hours or more is 0.64 wt % or less.

According to one embodiment, a magnetic recording medium includes: a substrate; and a magnetic recording layer structure formed above the substrate. The magnetic recording layer structure includes five or more magnetic recording layers and four or more nonmagnetic exchange coupling layers, where the magnetic recording layers and the nonmagnetic exchange coupling layers are arranged in an alternating pattern, and where the magnetic recording layers are separated from each other by least one of the nonmagnetic exchange coupling layers. The magnetic recording layer positioned closest to the substrate has each of the following: an average magnetic grain pitch of about 8.3 nm or less, a magnetic anisotropy field (H.sub.k) value of greater than or equal to about 20 kOe, and a thickness that is about 40% of a total thickness of the magnetic recording layer structure.

According to one embodiment, a magnetic recording medium includes: a substrate; and a magnetic recording layer structure formed above the substrate. The magnetic recording layer structure includes five or more magnetic recording layers and four or more nonmagnetic exchange coupling layers, where the magnetic recording layers and the nonmagnetic exchange coupling layers are arranged in an alternating pattern, and where the magnetic recording layers are separated from each other by least one of the nonmagnetic exchange coupling layers. The magnetic recording layer positioned closest to the substrate has each of the following: an average magnetic grain pitch of about 8.3 nm or less, a magnetic anisotropy field (H.sub.k) value of greater than or equal to about 20 kOe, and a thickness that is about 40% of a total thickness of the magnetic recording layer structure.

There is provided a magnetic recording medium of which an average thickness t.sub.T is t.sub.T5.6 m, a dimensional change amount w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/Nw, a squareness ratio in a vertical direction is 65% or more, and a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is 0.06 mb0.06 m.