A magnetic recording medium includes a long-shaped base substrate having flexibility, a soft magnetic layer, and a magnetic recording layer. A squareness ratio in a longitudinal direction of the base substrate is equal to or less than a squareness ratio in a short-side direction of the base substrate. The squareness ratio in the longitudinal direction of the base substrate is 30% or less.

Provided herein is an apparatus including a top continuous layer and a bottom continuous layer under the top continuous layer. The top continuous layer and the bottom continuous layer are antiferromagnetically coupled. A number of granular columns are under the bottom continuous layer. The number of granular columns include at least a first granular layer under the bottom continuous layer and a second granular layer also under the first granular layer. The first granular layer and the second granular layer are separated by a non-magnetic spacer. The first granular layer and the second granular layer are ferromagnetically coupled. The first granular layer is antiferromagnetically coupled to the bottom continuous layer.

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.

Magnetic recording media including a soft magnetic underlayer (SUL) formed over an oxidized pre-seed layer. In some examples, the pre-seed layer is oxidized to reduce an amount of intermixing between the pre-seed layer and the SUL. The reduction in intermixing via oxidation can lead to improved recording performance of the recording media that are deposited on the SUL. In particular, media overwrite, signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a deposition apparatus may be modified to inject oxygen during pre-seed layer deposition to oxidize the pre-seed layer.

Magnetic recording media including a soft magnetic underlayer (SUL) formed over an oxidized pre-seed layer. In some examples, the pre-seed layer is oxidized to reduce an amount of intermixing between the pre-seed layer and the SUL. The reduction in intermixing via oxidation can lead to improved recording performance of the recording media that are deposited on the SUL. In particular, media overwrite, signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a deposition apparatus may be modified to inject oxygen during pre-seed layer deposition to oxidize the pre-seed layer.

Aspects of the present disclosure provide a heat assisted magnetic recording HAMR media structure and methods for reducing the Curie temperature distribution to improve the signal-to-noise characteristics of HAMR media. A magnetic recording medium includes a substrate, a heat sink layer on the substrate, and a magnetic recording layer on the heat sink layer. The magnetic recording layer includes a plurality of magnetic recording grains configured for recording and comprising a first magnetic alloy. The magnetic recording layer further includes a plurality of segregants disposed to isolate the plurality of magnetic recording grains and comprising a second magnetic alloy. A Curie temperature of the second magnetic alloy is higher than a Curie temperature of the first magnetic alloy.

A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, and the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1≤0.8.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

A magnetic recording medium includes a non-magnetic substrate; a soft magnetic layer; a first seed layer; a second seed layer; an underlayer; and a perpendicular magnetic recording layer. The soft magnetic layer, the first seed layer, the second seed layer, the underlayer and the perpendicular magnetic recording layer are disposed on the non-magnetic substrate in this order. The first seed layer includes MoS.sub.2, hexagonal-BN, WS.sub.2, WSe.sub.2 or graphite. The second seed layer includes AlN having a hexagonal wurtzite type crystal structure. The underlayer includes Ru.