Heat-assisted magnetic recording (HAMR) medium with multilayered underlayer for the recording layer

    公开(公告)号:US11521648B2

    公开(公告)日:2022-12-06

    申请号:US17171852

    申请日:2021-02-09

    IPC分类号: G11B5/66 G11B5/73 G11B5/82

    摘要: A heat-assisted magnetic recording (HAMR) medium has a multilayered underlayer between the heat-sink layer and the recording layer. One embodiment of the underlayer is a multilayer of a thermal barrier layer consisting essentially of MgO and TiO, and a seed layer containing MgO and nitrogen (N) directly on the thermal barrier layer, with the recording layer on and in contact with the seed layer. The interface between the thermal barrier layer and the seed layer contains Ti and N, some of which may be present as TiN to act as a diffusion barrier to prevent diffusion of the Ti into the recording layer. The Ti-containing thermal barrier layer has a higher thermal resistivity than the conventional MgO thermal barrier/seed layer and thus allows for reduced laser power to the recording layer while still achieving a high thermal gradient at the recording layer.

    MAGNETIC RECORDING MEDIUM
    4.
    发明申请

    公开(公告)号:US20220165302A1

    公开(公告)日:2022-05-26

    申请号:US16649482

    申请日:2019-10-03

    申请人: Sony Corporation

    摘要: An object is to provide a magnetic recording medium having excellent traveling stability and a thin total thickness.
    The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which a surface on a side of the magnetic layer has a kurtosis of 3.0 or more, a surface on a side of the back layer has a kurtosis of 2.0 or more, the surface on the magnetic layer side has arithmetic average roughness Ra of 2.5 nm or less, the base layer includes a polyester as a main component, the magnetic recording medium has an average thickness tT of 5.6 μm or less, the magnetic recording medium includes a lubricant, the lubricant includes a fatty acid and a fatty acid ester, and a mass ratio between the fatty acid and the fatty acid ester extracted with hexane satisfies fatty acid/fatty acid ester ≤0.6, and the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried.

    Magnetic recording medium with multiple exchange coupling layers and small grain magnetic layers

    公开(公告)号:US11276428B2

    公开(公告)日:2022-03-15

    申请号:US16904400

    申请日:2020-06-17

    发明人: Yoshihiro Ikeda

    IPC分类号: G11B5/667 G11B5/65 G11B5/66

    摘要: A magnetic recording medium is provided that includes a recording layer structure including a first magnetic recording layer, a second magnetic recording layer, a third magnetic recording layer, a fourth magnetic recording layer, and a plurality of nonmagnetic exchange coupling layers. The first magnetic recording layer is closest to a substrate and the fourth magnetic recording layer is farthest from the substrate. An amount of Co in the first magnetic recording layer is greater than or equal to the amount of Co in the second magnetic recording layer, the third magnetic recording layer, and the fourth magnetic recording layer.

    Magnetic recording medium having magnetic layer with hydride of carbon, and magnetic storage apparatus

    公开(公告)号:US10984829B2

    公开(公告)日:2021-04-20

    申请号:US16279143

    申请日:2019-02-19

    申请人: SHOWA DENKO K.K.

    摘要: 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.

    MAGNETIC RECORDING CARTRIDGE
    9.
    发明申请

    公开(公告)号:US20200342907A1

    公开(公告)日:2020-10-29

    申请号:US16502418

    申请日:2019-07-03

    申请人: Sony Corporation

    摘要: A magnetic recording cartridge includes a magnetic recording medium of which an average thickness tT is tT≤5.6 μm, a dimensional change amount Δw in a width direction with respect to a tension change in a longitudinal direction is 660 ppm/N≤Δw, and a squareness ratio in a vertical direction is 65% or more, in which the magnetic recording medium is accommodated in a state of being wound around a reel 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.

    MAGNETIC HEAD AND MAGNETIC RECORDING AND REPRODUCING DEVICE

    公开(公告)号:US20200327901A1

    公开(公告)日:2020-10-15

    申请号:US16914382

    申请日:2020-06-28

    摘要: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, and a stacked body. The stacked body is provided between the magnetic pole and the first shield. The stacked body includes a magnetic layer including at least one selected from the group consisting of Fe, Co, and Ni, a first conductive layer provided between the magnetic pole and the magnetic layer, the first conductive layer being nonmagnetic, and a second conductive layer provided between the magnetic layer and the first shield, the second conductive layer being nonmagnetic. The first conductive layer includes Ir. A thickness of the first conductive layer along a first direction is not less than 0.3 nm and not more than 0.8 nm. The first direction is from the first conductive layer toward the second conductive layer.