Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Hitachi Storage Technologies Japan, Ltd.

Yotsuo Yahisa

Yoshibumi Matsuda

Yuzuru Hosoe

Tetsuya Kanbe

Hiroyuki Suzuki

Yoshihiro Shiroishi

Tomoo Yamamoto

Akira Ishikawa

Koji Sakamoto

Kiwamu Tanahashi

Masaki Ohura

Tomoyuki Ohno

Hidekazu Kashiwase

Sadao Hishiyama

Akira Kato

Ichiro Tamai

Kazumasa Takagi

Norikazu Tsumita

Akira Osaki

Noriyuki Shige

Yoshiyuki Hirayama

Tatsuya Hinoue

Takaaki Shirakura

Hiroyuki Kataoka

Yoshiki Kato

Toshinori Ono

Shinji Fukaya

Naoto Endo

Jun Fumioka

Kazuhiro Ura

Jo Inagaki

Akemi Hirotsune

Masukazu Igarashi

Yoshio Takahashi

Masatoshi Takeshita

Joe Inagaki

Yukio Katoh

Kazuetsu Yoshida

Shinji Narishige

Naoki Kodama

Hiroshi Tani

Futoshi Tomiyama

Yukio Kato

Katsuo Abe

Mitsuhiro Shoda

Youichi Inomata

Masatomo Terakado

Kiyoshi Akamatsu

Yoko Ogawa

Susumu Funamoto

Emi Mangyo

Takao Yonekawa

Masae Suzuki, Legal Representative

Hiroyuko Suzuki

Shinichiro Saitoh

Suzuki Hiroyuki

Yuichi Ootani

Enji Fujita

According to one embodiment, a perpendicular magnetic recording medium includes a soft magnetic underlayer formed above a substrate, a lower seed layer formed above the soft magnetic underlayer, at least one upper seed layer formed above the lower seed layer, an interlayer formed above the at least one upper seed layer, a perpendicular recording layer formed above the interlayer, and a protective layer formed above the perpendicular recording layer, wherein the at least one upper seed layer comprises Ni or a Ni based alloy including N, and wherein the lower seed layer includes Ni and at least one element selected from a group consisting of: W and Cr. Other embodiments are described herein regarding perpendicular magnetic recording systems and methods of producing perpendicular magnetic media.

Perpendicular magnetic recording medium and magnetic storage apparatus 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

In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron. The concentration of chromium contained in the third magnetic layer is lower than that of chromium contained in the second magnetic layer.

Magnetic recording medium having a cobalt-based alloy film for high density recording and magnetic storage device using same

An inplane magnetic recording medium having high S/N and thermal stability and a reliable magnetic storage device having surface recording density of 50 megabit/mmor more is described. The magnetic recording medium includes magnetic layers formed on a nonmagnetic substrate with a plurality of ground layers therebetween, at least one of the ground layers formed from an alloy of a body-centered cubic structure containing Cr as a main component and B of from 2 atomic % to 12 atomic %. Main components of the magnetic layers include a lower magnetic layer containing Co and Cr of from 10 atomic % to 16 atomic %, with film thickness of from 1.5 nm to 4.5 nm, and an upper magnetic layer containing Co, coupling anti-ferromagnetically with the lower magnetic layer through nonmagnetic intermediate layers.

Magnetic recording medium and magnetic storage device

A magnetic recording apparatus including a drive unit to drive the magnetic recording medium, a compound-type magnetic head, a means to move the magnetic head relative to the magnetic recording medium, and a means to process recording and retrieving signals generated by the magnetic head. The magnetic recording medium comprises a non-magnetic substrate and a magnetic layer formed thereon with three underlayers interposed inbetween. The magnetic layer is composed of a plurality of layers of Co-based alloy of hexagonal close-packed structure which are antiferromagnetically coupled to one another through a non-magnetic intermediate layer, said three underlayers including an amorphous alloy layer, a Ta layer, and a Cr-based alloy layer of body-centered cubic structure.

Magnetic recording medium and magnetic recording apparatus

A magnetic recording medium having at least two magnetic layers and a non-magnetic intermediate layer held between them. The first magnetic layer (which is closer to the substrate than the non-magnetic intermediate layer) is formed from an alloy composed of Co, Pr, and Cr, with Pt content being 3-9 at %. The second magnetic layer (which is farther from the substrate than the non-magnetic intermediate layer) is formed from a Co-based alloy containing Pt, Cr, and B. The first and second magnetic layers are magnetized in the mutually antiparallel direction in the absence of an applied magnetic field. The magnetic recording medium is characterized by good thermal stability for recording bits, high recording resolution, and low media noise. It is suitable for a magnetic storage for high recording density with high reliability.

Magnetic recording medium and magnetic recording system using the same

Disclosed is a magnetic recording medium and a method for manufacturing the same to provide a magnetic recording medium reducing medium noise and having excellent thermal stability. The magnetic recording medium includes a substantially amorphous seed layer and a polycrystal underlayer made of crystal grains having a substantially columnar structure, the polycrystal underlayer contacting thereto. In a boundary between the seed layer and the underlayer, fine grooves having a period up to as large as the magnetic layer crystal grain diameter are formed in the disc circumferential direction. Accordingly, the magnetic recording medium is allowed to have a grain shape with a value obtained by dividing the average grain diameter for the disc circumferential direction by the average grain diameter for the disc radial direction of no less than 0.5 and no more than 0.9, thus achieving simultaneously reduction of the medium noise and thermal stability.

Method for manufacturing a magnetic medium

A large-capacity, low-cost, longitudinal magnetic recording medium capable of ultra-high-density recording of 70 Gigabits or more per square inch is disclosed. The longitudinal magnetic recording medium of the present invention comprises a first seed layer, a second seed layer, a first underlayer, a second underlayer, and a magnetic layer, which are formed on a nonmagnetic substrate in this order. A material containing at least Al and any one of Ru and Re is used to form the second seed layer, and a material containing at least any one of Co and Ni and one or both of Al and Ti is used to form the first underlayer. It is also possible to use Cr or a Cr alloy containing Cr and at least one element selected from the constituent element group A consisting of Ti, Mo, and W for forming the second seed layer.

Magnetic recording medium

A magnetic recording system includes an in-plane magnetic recording medium having a magnetic layer fabricated on a single underlayer or on a plurality of underlayers respectively fabricated on a substrate; a driver unit for driving the in-plane magnetic recording medium in a write direction; a magnetic head having a read unit and a write unit; a unit for moving the magnetic head relative to the in-plane magnetic recording medium; and a read/write signal processing unit for reading an output signal from the magnetic head and writing an input signal to the magnetic recording media, wherein the read unit of the magnetic head is a magnetoresistive head and the single underlayer or at least one of the plurality of underlayers is made of Co-containing amorphous material or fine crystal material, or is made of alloy material, the alloy material having as the main components at least one element selected from a group consisting of Cr, Mo, V and Ta and containing at least one element selected from a group consisting of B, C, P and Bi. The magnetic recording system can be realized which can read and write high density information and have high reliability.

Magnetic recording media and magnetic recording system using the same

The longitudinal magnetic recording medium includes a non-magnetic substrate, a first underlayer having at least one of an amorphous structure and a fine crystal structure formed on the non-magnetic substrate, a second underlayer having a body-centered cubic structure formed on the first underlayer, a third underlayer having a hexagonal closed packed structure formed on the second underlayer, and a magnetic layer having the hexagonal closed packed structure formed on the third underlayer, wherein the third underlayer is composed of an alloy containing Co and Ru.

Magnetic recording medium with controlled grain diameters and method for manufacturing the same

It is an object of the present invention to provide a high reliability magnetic storage apparatus capable of performing writing and reading back of high density information. The magnetic storage apparatus is so configured as to have a longitudinal magnetic recording medium including: a magnetic layer formed on a non-magnetic substrate via a plurality of underlayers; the magnetic layer including a lower magnetic layer containing Ru in an amount of not less than 3 at % to not more than 30 at %, and Cr in an amount of not less than 0 at % to not more than 18 at %, and further containing at least one of B or C in an amount of not less than 0 at % to not more than 20 at %, and an upper magnetic layer containing Co as a main component disposed thereon via a non-magnetic intermediate layer.

A magnetic recording medium includes a first underlying film of a NiTa alloy having a nonmagnetic amorphous structure and formed on a nonmagnetic substrate, and a second underlying film made of an alloy containing Cr and Ti, further a first magnetic film of a CoCrPt alloy, a nonmagnetic intermediate film of Ru and a second magnetic film of a CoCrPtB alloy that are serially formed over the first underlying film, wherein oxygen locally exists in an interface between the first underlying film and the second underlying film.

Magnetic recording medium and manufacturing method thereof

Growing community of inventors

Odawara, Japan

Yotsuo Yahisa