Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Nagatugu Koiso

Fumiyoshi Kirino

Yuzuru Hosoe

Noriyuki Kumasaka

Kiwamu Tanahashi

Yoshio Takahashi

Ichiro Tamai

Tetsuya Kanbe

Satoshi Matsunuma

Hiroshi Umezaki

Takeshi Miura

Yutaka Sugita

Shigekazu Otomo

Hirozi Yamada

Hideki Nishida

Katsuhiro Kaneko

Ryo Suzuki

Toshio Kobayashi

Tadashi Ikeda

Hitoshi Nakamura

Teruaki Takeuchi

Ryoichi Nakatani

Ryo Imura

Norikazu Tsumita

Shigeharu Otomo

Masatake Takahashi, Deceased

In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, means for causing the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor means for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magnetoresistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of the underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as selected from the group consisting of Nb and Ta.

Magnetic recording media and magnetic storage apparatus using the same

In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, a way to cause the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magnetoresistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of hte underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as selected from the group consisting of Nb and Ta.

Magnetic storage apparatus

In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, means for causing the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor means for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magneto-resistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of the underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as selected from the group consisting of Nb and Ta.

Magnetic recording media

A recording head for recording data onto a recording medium is provided with a thin film formed of the following compound Fe.sub.100-a-b-c X.sub.a Y.sub.b Z.sub.c, wherein X is at least one element selected from the group consisting of Nb, Ta, Hf and Zr, Y is one or two elements selected from the group consisting of Cr, Ru, Al, Si, Ti and Rh, and Z is at least one element selected from the group consisting of C and N, and wherein 5.ltoreq.a.ltoreq.20, 0.5.ltoreq.b.ltoreq.15, 1.ltoreq.c.ltoreq.20, and 0.5.ltoreq.a/c.ltoreq.0.7, the carbide or the nitride of the element X having an average grain size of not larger than 3 nm. This way, increased corrosion resistance is provided without substantially reducing magnetic characteristics such as saturation and coercive force. A recording apparatus, such as a VTR, including such a recording head is disclosed as well as a recording medium formed using this thin film.

Soft magnetic thin film, and magnetic head and magnetic recording device

To obtain a soft magnetic thin film having improved soft magnetic characteristics, thermal stability and corrosion resistance, this invention uses a soft magnetic thin film comprising Fe as the principal component thereof and containing Ta and/or Hf and C and/or N, wherein the (110) plane of Fe is preferentially oriented, the size d.sub.1 of the Fe crystal particle is not greater than 15 nm and the size d.sub.2 of the Ta--C, Ta--N, Hf--C or Hf--N particle is not greater than 3 nm. The crystal particle size is controlled by causing first the Fe crystal particle to precipitate at the initial stage of the film formation and then causing the crystal particle of Ta--C, Ta--N, Hf--C or Hf--N to precipitate.

Soft magnetic thin film, and magnetic head and magnetic recording

Corrosion resistance of a magnetic film composed mainly of Fe is maintained while keeping its magnetic properties. A magnetic head having a magnetic core is formed in part of the magnetic thin film, which contains not only an alloy of Fe-metalloid series but also (Al, Ru) or (Al, Rh) and which is thermally treated at a constant temperature to develop the soft magnetic properties. The deterioration of the saturation magnetization and the soft magnetic properties is suppressed by adding (Al, Ru) or (Al, Rh) together. The magnetic film has a high saturation magnetization and excellent soft magnetic properties and is excellent in corrosion resistance and hardness.

A ferromagnetic film which comprises ferromagnetic metal in which an oxide phase is present, a method for producing it, and a magnetic head in which said ferromagnetic film is used are disclosed. The ferromagnetic metal includes iron and cobalt and the oxide phase contains preferably at least one element selected from IVa, Va and VIa group elements.

Magnetic film having a magnetic phase with crystallites of 200 A or less

A method of implanting a magnetic garnet film with ions is disclosed in which a covering film is provided on a monocrystalline magnetic garnet film for magnetic bubbles, and hydrogen ions are implanted in a desired portion of a surface region in the magnetic garnet film through the covering film. According to this method, it is possible to form an ion-implanted layer in which the ion concentration distribution in the direction of depth is uniform, and moreover the inplane anisotropy field in the ion-implanted layer decreases only a little with time in an annealing process.

Method of making magnetic bubble memory device by implanting hydrogen

A method of forming a microscopic pattern wherein the object to be etched is overlaid with a film made of a material which is highly immune to etching and further provided with a reflection reducing film. Thus, the reflection of the irradiating ultraviolet rays by the underlying layer is effectively prevented.

Method of forming a microscopic pattern

A magnetic bubble memory device is disclosed in which a hardened film made of a heat-resisting highly-polymerized organic resin and having a predetermined thickness is employed for an insulating film interposed between a conductor pattern and a soft magnetic material pattern. In a conventional magnetic bubble memory device in which the above-mentioned insulating film is made of SiO.sub.2, an abrupt step is produced in the soft magnetic material pattern due to the existence of the conductor pattern beneath a portion of the soft magnetic material pattern, and the margin of bias magnetic field is thereby lowered. According to the present invention, the step is reduced and smoothed, and thus the lowering of the margin can be prevented.

Growing community of inventors

Tama, Japan

Nagatugu Koiso