Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Netherlands B.v.

Western Digital Technologies, Inc.

Kiwamu Tanahashi

Yuzuru Hosoe

Ichiro Tamai

Tetsuya Kanbe

Atsushi Kikugawa

Yoshio Takahashi

Akira Ishikawa

Tomoo Yamamoto

Yukio Honda

Yotsuo Yahisa

Hiroyuki Nakagawa

Masaaki Futamoto

Satoshi Matsunuma

Yoshihiro Shiroishi

Reiko Arai

Yoshibumi Matsuda

Yoshiyuki Hirayama

Noboru Shimizu

Shun Tonooka

Masayoshi Shimizu

Fumiyoshi Kirino

Kazuetsu Yoshida

Yoshinori Honda

Toshinori Ono

Hiroyuki Kataoka

Nagatugu Koiso

Akira Osaki

Shinji Fukaya

Naoto Endo

Kazuhiro Ura

Yoshifumi Matsuda

Hiroyuki Suzuki

Yohji Maruyama

Mikio Suzuki

Yoshiki Kato

Masatoshi Takeshita

Masaki Ohura

Takayuki Ichihara

Takanobu Takayama

Jun Fumioka

Yukio Katoh

Atsushi Nakamura

Akemi Hirotsune

Akira Kato

Masukazu Igarashi

Shinji Narishige

Naoki Kodama

Hiroaki Nemoto

Yoshihiro Ikeda

Koji Sakamoto

Futoshi Tomiyama

Ikuko Takekuma

Yuko Tsuchiya

Katsuo Abe

Gunn Choe

Mineaki Kodama

Maki Maeda

Emi Mangyo

Zhengang Zhang

A magnetic media for magnetic data recording having reduced signal noise. The magnetic media includes a magnetic recording layer that has first, second and third portions. The first portion at the bottom of the magnetic recording layer includes an oxide and has a high anisotropy field. The third portion, located at the top of the magnetic recording layer has a low anisotropy field and does not include an oxide. The second portion, located between the first and third portions has an anisotropy field that is between that of the first and third magnetic portions. The second portion includes a thin layer of a material that has an extremely low anisotropy field that is located within a material having a higher magnetic anisotropy.

Perpendicular magnetic recording media having an extremely low Hk layer

In one embodiment, a perpendicular magnetic recording medium includes: a substrate; and a soft magnetic underlayer structure positioned above the substrate, where the soft magnetic underlayer includes: a coupling layer; a first soft underlayer positioned above the coupling layer; and a second soft underlayer positioned below the coupling layer, where a difference between a magnetic flux density of the soft magnetic underlayer structure at 25&#xb0; C. and a magnetic flux density of the soft underlayer structure at 85&#xb0; C. is less than or equal to about 10% of the magnetic flux density of the soft magnetic underlayer structure at 25&#xb0; C.

Soft magnetic underlayer having high temperature robustness for high areal density perpendicular recording media

In one embodiment, a perpendicular magnetic recording medium includes an oxide recording layer including an oxide and a non-oxide recording layer which does not contain an oxide positioned above the oxide recording layer. The oxide recording layer includes a region Rwhere a grain boundary width in a direction parallel to a plane of formation of Rincreases therealong from a lowermost portion of the oxide recording layer toward a medium surface, a region Rpositioned above Rwherein a grain boundary width increases therealong toward the medium surface, a region Rwhere a grain boundary width of Rdecreases therealong from Rto R, with Rbeing positioned between Rand R, and a region Rwhere a grain boundary width of Rdecreases therealong from Rtoward the medium surface, with Rbeing positioned above Rand near an uppermost portion of the oxide recording layer.

Perpendicular magnetic recording medium with grain boundary controlling layers

Embodiments of the invention provide a manufacturing method which permits a high quality perpendicular magnetic recording medium to be manufactured with a high yield by preventing abnormal discharge which sputters particles from the target. In one embodiment, while the perpendicular magnetic recording medium is formed, DC pulses are applied to the target. During the reversal period (Reversal Time) between sputtering periods, a voltage of the opposite polarity is applied. During the sputtering period, a negative voltage is applied which biases the target surface to a negative potential, causing Ar+ to collide with and sputter CoCrPt and SiOfor deposition on the intermediate layer. The top surface of the insulation material (SiO) on the target is charged by Ar+ to have a voltage larger than the target voltage. However, arcing can be prevented since the charge on the surface of the insulation material is neutralized due to a positive voltage applied to the target during the non-sputtering period.

Method for manufacturing perpendicular magnetic recording medium

According to one embodiment, a PMRM includes a substrate, a soft magnetic underlayer above the substrate, an underlayer above the soft magnetic underlayer, an oxide-containing magnetic layer above the underlayer, and a ferromagnetic layer above the magnetic layer having no oxides. The underlayer controls orientation and segregation of the magnetic layer. The oxide-containing magnetic layer comprises at least two or more magnetic layers, a Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer is between about 23 at. % and about 32 at. %, and a difference between the Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer and a magnetic layer having a lowest Cr concentration among the at least three magnetic layers is less than about 25 at. %, the magnetic layer with a lowest Cr concentration has a granular structure, and a nucleation field is greater than about 159.2 kA/m.

Perpendicular magnetic recording medium (PMRM) and magnetic storage device using the same

In one embodiment, a perpendicular magnetic recording medium includes a substrate, a soft-magnetic underlayer above the substrate, a seed layer above the soft-magnetic underlayer, a first intermediate layer above the seed layer, a second intermediate layer above the first intermediate layer, a recording layer above the second intermediate layer, and a protective layer above the recording layer. The second intermediate layer includes an Ru alloy having an element selected from a group consisting of: Ti in a range from about 20 at. % to about 50 at. %, Nb in a range from about 20 at. % to about 50 at. %, Al in a range from about 20 at. % to about 40 at. %, Ta in a range from about 30 at. % to about 50 at. %, and Si in a range about 20 at. % to about 40 at. %. Other magnetic media and systems using this media are described according to more embodiments.

Perpendicular magnetic recording media having low medium noise and systems using the same

Embodiments of the present invention provide a perpendicular magnetic recording medium that reduces the noise of granular recording layers, obtains sufficient overwrite characteristic that suppresses an increase in the magnetic cluster size, and allows high-density recording. According to one embodiment, a perpendicular magnetic recording medium comprising substrate having thereon at least soft magnetic layer, nonmagnetic intermediate layer, a perpendicular recording layer and protective layer formed in that order. The perpendicular recording layer consists of three or more layers of first recording layer, a second recording layer, and a third recording layer from the side nearer to the substrate. The first recording layer and the second recording layer have a granular structure comprising a grain boundary of an oxide surrounding ferromagnetic crystal grains containing Co and Pt, and the third recording layer has a non-granular structure mainly comprising Co and not containing an oxide. The grain boundary of the first recording layer contains Si, Cr and oxygen, and at least one element selected from Ti, Ta and Nb, and the grain boundary of the second recording layer contains Cr and oxygen, or contains Cr and oxygen and at least one element selected from Si, W and V.

Perpendicular magnetic recording medium and magnetic storage device using the same

According to one embodiment, a perpendicular magnetic recording medium includes at least one soft magnetic underlayer above a substrate, a seed layer above the at least one soft magnetic underlayer, an intermediate layer above the seed layer, a magnetic recording layer above the intermediate layer, and an overcoat layer above the magnetic recording layer, wherein the seed layer includes a second seed layer above a first seed layer. In another embodiment, the seed layer is a multilayered structure of at least two cycles of a unit of layered film which includes a first seed layer and a second seed layer. The first seed layer includes a non-magnetic alloy having a Face-Centered-Cubic (FCC) structure, and the second seed layer includes a soft magnetic alloy having a FCC structure. Other structures are also disclosed, according to more embodiments.

Perpendicular magnetic recording medium having FCC seed layers

According to one embodiment, a magnetic recording medium includes a magnetic recording layer formed above a substrate, comprising: a first magnetic layer formed from a [Co/Pt]multilayered film, wherein the first magnetic layer has a face-centered cubic (fcc) (111) crystal structure, the (111) direction being perpendicular to a film surface thereof, and a second magnetic layer comprising a CoCrPt or CoCrPt alloy film formed above the first magnetic layer, wherein the second magnetic layer has a hexagonal close packed (hcp) (00.1) crystal structure, the (00.1) direction being perpendicular to a film surface thereof. According to another embodiment, a system includes a magnetic recording medium as described above, a magnetic head for reading from and/or writing to the magnetic recording medium, a magnetic head slider for supporting the magnetic head, and a control unit coupled to the magnetic head for controlling operation of the magnetic head.

[object Object]

Soft magnetic film fabricated with preferred uniaxial anisotropy for perpendicular recording. One type of cathode design has a field direction that is parallel to the direction of the Hex of the second SUL with a magnetically-pinned first SUL. In addition, SUL structures having low AP exchange energy also are disclosed. The SUL structure combines the cathode field direction of the SULwith the pinned SUL. The SULis magnetically pinned to the pinning layer and the pinning direction is parallel to the direction of the cathode field applied during deposition of the SUL. High Hc ferro-magnetic materials may be deposited onto a heated substrate that is magnetized along the radial direction by the cathode field. The pinning field may be higher than the cathode field, indicating that the cathode field during deposition of the SULcannot disturb the magnetic state of the SULpinned to pinning layer.

Methods and apparatus to fabricate soft magnetic film with preferred uniaxial anisotropy for perpendicular recording

Embodiments of the present invention provide a perpendicular magnetic recording medium having a substrate, a magnetic recording layer and a protective layer. The magnetic recording layer includes a perpendicular recording layer, a magnetic coupling layer and a writing assist layer. The perpendicular recording layer is a Co alloy layer containing an oxide disposed between the magnetic coupling layer and the substrate. The magnetic coupling layer is a ferromagnetic layer disposed between the perpendicular recording layer and the writing assist layer. The writing assist layer is a ferromagnetic layer disposed between the magnetic coupling layer and the protective layer. The saturation magnetization of the magnetic coupling layer is lower than the saturation magnetization of the perpendicular recording layer or the writing assist layer. The thickness of the magnetic coupling layer is 1 nm or more and 3 nm or less.

Perpendicular magnetic recording medium and system having a magnetic recording layer with a perpendicular recording layer, a magnetic coupling layer, and a writing assist layer

Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nonmagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

Perpendicular magnetic recording medium, manufacturing process of the same, and magnetic recording/reproducing apparatus using the same

A perpendicular magnetic recording medium is manufactured having excellent thermal stability and recording performances across the entire disk surface. In one embodiment, the recording layer includes at least two layers deposited by using a reactive sputtering method under an oxygen-containing atmosphere at a deposition rate larger than the second recording layer which is formed on the first recording layer while depositing the first recording layer on the intermediate layer.

Manufacturing process for perpendicular magnetic recording medium

There is provided a perpendicular magnetic recording medium comprising a non-magnetic layer having a face-centered cubic structure, an antiferromagnetic layer provided on the non-magnetic layer, a soft magnetic underlayer provided on the antiferromagnetic layer, and a perpendicular recording layer provided on the soft magnetic underlayer, which magnetic recording medium makes it possible to realize a recording density not less than 50 Gb/inand makes the error rate thereof low while suppressing the spike noise.

Perpendicular magnetic recording media

A magnetic recording/reproducing apparatus is disclosed with high storage capability. The apparatus also prevents fluctuation of readback output and decay of magnetization or erasure of recorded magnetization in the recording layer. A soft magnetic underlayer and a perpendicular recording layer are formed in specific order on the substrate of a magnetic disk. The soft magnetic underlayer has a triple-layered structure in which a domain control layer, including an anti-ferromagnetic layer, is sandwiched between two first and second soft magnetic layers. The thickness of the first and second soft magnetic layers (d, d) is between 25 nm and 150 nm and a ratio of d/dis within a range of 0.3 to 1.5. Accordingly, magnetic domains in the soft magnetic underlayer of a perpendicular magnetic recording medium can be controlled and magnetic domain wall motion can be inhibited.

Perpendicular magnetic recording medium and magnetic recording/reproducing apparatus

Growing community of inventors

Kokubunji, Japan

Kiwamu Tanahashi