Various embodiments provide for a heat assisted magnetic recording (HAMR) media comprising: a magnetic recording layer; a barrier layer disposed under the magnetic recording layer; a first underlayer disposed under the barrier layer; and an amorphous seedlayer disposed under the first underlayer. For some embodiments, the recording medium may comprise: a magnetic recording layer including FePt alloy, a CoPt alloy, or a FePd alloy; a barrier layer including MgO, TiC, TiN, CrN, TiCN, β-WC, TaC, HfC, ZrC, VC, NbC, or NiO; a first underlayer including RuAl-oxide, NiAl, FeAl, AlMn, CuBe, or AlRe; or an amorphous seedlayer including a Cr—X alloy, where X comprises Al, B, C, Cu, Hf, Ho, Mn, Mo, Ni, Ta, Ti, V, W, or Ru.

Underlayers for heat assisted magnetic recording (HAMR) media

A perpendicular magnetic recording medium comprises a magnetic recording layer that records a signal, an underlayer formed of Ru or Ru compound below the magnetic recording layer, a non-magnetic layer formed of a non-magnetic material below the underlayer to control crystal orientation of the underlayer, a soft magnetic layer provided below the non-magnetic layer, and a substrate on which the magnetic recording layer, the underlayer, the non-magnetic layer, and the soft magnetic layer are formed. The non-magnetic layer comprises a first non-magnetic layer formed above the soft magnetic layer and a second non-magnetic layer formed above the first non-magnetic layer. The first non-magnetic layer is formed of amorphous Ni compound while the second non-magnetic layer is formed of crystalline Ni or crystalline Ni compound.

Perpendicular magnetic recording medium and method of manufacturing the same

A magnetic recording medium for perpendicular magnetic recording includes a substrate, a granular layer having magnetic crystal grains exhibiting perpendicular magnetic anisotropy and nonmagnetic substances for magnetically separating the magnetic crystal grains from each other at grain boundaries of the magnetic crystal grains, and a continuous film layer having magnetic grains to be exchange-coupled to the magnetic crystal grains, the grain boundary width of the magnetic grains being smaller than that of the magnetic crystal grains, wherein separation regions for magnetically separating tracks from each other are disposed in regions between the tracks of the magnetic recording medium in at least the continuous film layer.

Magnetic recording medium and method for manufacturing magnetic recording medium

In a perpendicular magnetic recording medium which includes a substrate ( 1 ) of a nonmagnetic material, first and second nonmagnetic underlayers ( 4 and 5 ) formed on the substrate, and a perpendicular magnetic recording layer ( 6 ) formed on the first and the second nonmagnetic underlayers, the first nonmagnetic underlayer is made of an amorphous nonmagnetic metal material containing a metal element which forms a face-centered cubic (fcc) crystal structure by a simple substance. The second nonmagnetic underlayer is formed on the first nonmagnetic underlayer in contact with the first nonmagnetic underlayer and made of a nonmagnetic material containing a hexagonal close packed structure. The perpendicular magnetic recording layer is formed on the second nonmagnetic underlayer in contact with the second nonmagnetic layer.

Perpendicular magnetic recording medium

An object of the present invention is to provide a perpendicular magnetic recording medium in which each space between crystal grains of a first magnetic recording layer is so designed as to allow the layer to also have a function as a continuous layer, and a method of manufacturing a perpendicular magnetic recording medium. In a perpendicular magnetic recording medium 100 according to the present invention, a first magnetic recording layer 122 a and a second magnetic recording layer 122 b are ferromagnetic layers each having a granular structure in which a grain boundary part made of a non-magnetic substance is formed between crystal grains each grown in a column shape and, in the first magnetic recording layer 122 a , an intergranular distance defined by an average of shortest distances between grain boundary parts each between a crystal grain and its adjacent crystal grain is equal to or shorter than 1 nm.

Perpendicular magnetic recording medium and process for manufacture thereof

[PROBLEMS] To improve the track density by reducing the track edge noise and sharpening the boundary between the recording magnetic fields by blocking the recording magnetic field spreading outside the recording region in magnetic recording. [MEANS FOR SOLVING PROBLEMS] A magnetic recording medium (10) has a substrate (12) and a vertical magnetic recording layer (30) formed over the substrate (12). The vertical magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20). The continuous film layer (24) has hard magnetic parts (204) formed in positions corresponding to the recording regions where magnetic signals are recorded in the granular layer (20) and magnetic shield parts (202) formed between the hard magnetic parts (204), each having a magnetization curve whose slope is larger than those of the hard magnetic parts in the region where the applied magnetic filed is zero when the magnetization curve is measured, and each having a residual magnetic polarization smaller than those in the hard magnetic parts.

Magnetic recording medium, magnetic recording medium manufacturing method, and magnetic disk

To provide a perpendicular magnetic recording disk having a film structure that improves overwrite characteristics (O/W) while maintaining a coercive force (Hc) high enough not to affect heat fluctuation resistance, and a manufacturing method thereof. A magnetic disk for use in perpendicular magnetic recording, having at least an underlayer, a first magnetic recording layer, and a second magnetic recording layer on a substrate in the order named, characterized in that the first magnetic recording layer and the second magnetic recording layer are each a ferromagnetic layer of a granular structure containing a nonmagnetic substance forming grain boundary portions between crystal grains containing at least Co (cobalt) and, given that the content of the nonmagnetic substance in the first magnetic recording layer is A mol % and the content of the nonmagnetic substance in the second magnetic recording layer is B mol %, A<B.

Perpendicular magnetic recording disk and method of manufacturing the same

[Object] To provide a manufacturing method that can easily enhance a reversed domain nucleation magnetic field of a magnetic recording layer in a perpendicular magnetic recording medium having, over a substrate, a soft magnetic layer, the magnetic recording layer having a granular structure, and a continuous layer having a high perpendicular magnetic anisotropy. [Solution] A perpendicular magnetic recording medium manufacturing method according to this invention is characterized by including a soft magnetic layer forming step of forming a soft magnetic layer over a substrate, a magnetic recording layer forming step of forming a magnetic recording layer having a granular structure as an upper layer of the soft magnetic layer, a continuous layer forming step of forming a continuous layer having a perpendicular magnetic anisotropy as an upper layer or a lower layer of the magnetic recording layer, and a heating step of heating a medium, obtained by forming the continuous layer in the continuous layer forming step, for improving a value of a reversed domain nucleation magnetic field.

Takahiro Onoue

Papers

Magnetic recording medium, magnetic recording medium manufacturing method, and magnetic disk

Perpendicular magnetic recording medium and method of manufacturing the same

Perpendicular magnetic recording medium and process for manufacture thereof

Perpendicular magnetic recording disk and method of manufacturing the same

Perpendicular magnetic recording medium manufacturing method