Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Technologies Japan, Ltd.

Takashi Kawabe

Moriaki Fuyama

Makoto Morijiri

Katsuro Watanabe

Hisashi Takano

Hiroshi Fukui

Shinji Narishige

Tadayuki Iwakura

Masaaki Sano

Kenzo Masuda

Shun-ichi Narumi

Yoshiaki Kita

Hisano Yamamoto

Yohji Maruyama

Takao Imagawa

Kazuhiro Nakamoto

Tetsuya Okai

Shunichiro Kuwatsuka

Hiroshi Ikeda

Yutaka Sugita

Hiromasa Takahashi

Nobuo Yoshida

Tomohiro Okada

Shigeru Tadokoro

Eiji Ashida

Harunobu Saito

Hiroshi Kamio

Atsushi Saito

Hiroyuki Hoshiya

Yoshihiro Shiroishi

Takehiko Hamaguchi

Hisashi Kimura

Naoki Koyama

Kazue Kudo

Kyo Akagi

Yasuyuki Okada

Masuo Umemoto

Yokuo Saitoh

Kouichirou Wakabayashi

Chiaki Ishikawa

Gen Oikawa

Reijiro Tsuchiya

Noriyuki Saiki

Makoto Aihara

Masatoshi Tsuchiya

Hideki Yamazaki

Shinobu Sasaki

Kaori Totsuka

Eizi Ashida

Makoto Saito

Atsushi Nakamura

Matahiro Komuro

Masaaki Hayashi

Mikio Suzuki

Noboru Shimizu

Kanji Kawakami

Katsumi Hoshino

Tetsuo Kobayashi

Masanobu Hanazono

Kazuo Nakagoshi

Kiyoshi Matsumoto

Masanori Tanabe

Masayasu Fujisawa

Issei Takemoto

Yosuke Hamada

Eisei Togawa

Saburo Suzuki

Yoshiki Hagiwara

Akira Onuma

Shinichi Hara

Yoshikazu Tsuji

Miki Hara

Shin-ichi Hara

Shun-ichi Marumi

Noboru Yoshida

Ataru Kobayashi

A magnetic head comprises a retrieving unit for converting magnetic information output from a recording medium into an electric signal, a writing unit having the function of electromagnetic conversion for writing the magnetic information in the recording medium in response to the electric signal, and a first protective film formed on the retrieving unit. A second protective film is formed on the first protective film. The coefficient of linear expansion of the second protective film is reduced in comparison with that of the first protective film. Furthermore, the first protective film is an alumina film; in contrast, the second protective film is a film made of an alumina film containing silicon oxide therein.

Magnetic head having first and second protective films with different coefficients of linear expansion

Disclosed is a magnetic disk apparatus including a magnetic reproducing head portion, and a magnetic recording head including an upper magnetic core having a end portion and a rear portion. As a resist for a frame which is used for forming the rear portion, a negative resist or an electron beam resist is used, whereby the frame is formed without any adverse effect of halation from a coil insulating film. That is, it is possible to manufacture a magnetic recording head in which the rear portion of an upper magnetic core is not emerged at the face opposed to a medium, and hence to obtain a magnetic disk apparatus exhibiting an areal recording density of 5 Gbit/inor more by mounting a magnetic recording/reproducing head including such a magnetic recording head.

Thin film magnetic head and magnetic disk apparatus including the same

A material for magnetic pole for attaining a writing head generating an intense recording magnetic field, and a structure and a manufacturing method therefor. The thin film magnetic head includes a magnetic pole layer having a plated magnetic layer containing Co, Ni and Fe formed on a plated underlayer of a sputtered magnetic layer containing Co, Ni and Fe. The CoNiFe magnetic layer having a composition: 40 wt %&#x2266;Co&#x2266;70 wt %, 10 wt %&#x2266;Ni&#x2266;25 wt % and 10 wt %&#x2266;Fe&#x2266;30 wt % and a peak intensity ratio in the X-ray diffraction of I(200)/I(111)&#x2267;0.5 and I(110)/I(111)&#x2267;1 (defining peak intensities for the face-centered cubic fcc (111) face, fcc (200) face and the body-centered cubic bcc (119) face as: I(111), I(200), I(110)).

Structure and plating method of thin film magnetic head and magnetic storage apparatus

Magnetic head for reducing projection of retrieving and writing unit from float surface, and magnetic recording/retrieving apparatus using the same

A material for magnetic pole for attaining a writing head generating an intense recording magnetic field, and a structure and a manufacturing method therefor. The thin film magnetic head includes a magnetic pole layer having a plated magnetic layer containing Co, Ni and Fe formed on a plated underlayer of a sputtered magnetic layer containing Co, Ni and Fe. The CoNiFe magnetic layer having a composition: 40 wt %&lE;Co&lE;70 wt %, 10 wt %&lE;Ni&lE;25 wt % and 10 wt %&lE;Fe&lE;30 wt % and a peak intensity ratio in the X-ray diffraction of I(200)/I(111)&gE;0.5 and I(110)/I(111)&gE;1 (defining peak intensities for the face-centered cubic fcc (111) face, fcc (200) face and the body-centered cubic bcc (119) face as: I(111), I(200), I(110)).

A magnetoresistive sensor which, despite a narrow reproducing shield gap, affords high resolution and high reproducing output because of its structure and is able to minimize the amount of sense current leaking into the shield layer through the gap layer. A magnetic storage apparatus suitable for high-density recording is provided with a magnetic head having said magnetoresistive sensor. The structure is characterized in that at least either of the lower shield layer or upper shield layer is partly or entirely a magnetic layer which is a composite film composed of ferromagnetic metal and oxide, and an insulation protective film is arranged between the electrode film or longitudinal bias film and the magnetic film which is a composite film composed of ferromagnetic metal and oxide.

Magnetoresistive sensor and magnetic storage apparatus

A magnetic disk apparatus includes a magnetic disk for recording information and a magnetic head which has a reproducing head and a recording head. The reproducing head comprising a lower shield film, a magnetoresistive film, a pair of electrodes and an upper shield, and the recording head comprising an upper magnetic core, a lower magnetic core, and a coil disposed between said upper magnetic core and said lower magnetic core. The upper magnetic core and the lower magnetic core include an electroplated thin film with an average crystal grain size smaller than 500 &angst;, and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Magnetic disk apparatus with magnetic head having upper and lower magnetic cores of an electroplated thin film

A magnetic head include a pair of magnetic shield layers, a pair of gap layers formed between the pair of magnetic shield layers, a magnetoresistive layer arranged between the pair of gap layers, and a pair of electrodes electrically connected to the magnetoresistive layer. At least one of the pair of magnetic shield layers is formed as a discontinuous multi-layer or as a mixed layer.

Magnetic head having magnetic shield layers

A slider having a thin film magnetic head. The thin film magnetic head has an upper magnetic core, a lower magnetic core and a coil disposed between the upper magnetic core and the lower magnetic core. The upper magnetic core and the lower magnetic core is an electroplated thin film with an average crystal grain size smaller than 500 &angst;, and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Thin film magnetic head with electroplated Ni-Fe alloy thin film having small average crystal grain size range

Disclosed is a magnetic disk apparatus including a magnetic reproducing head portion, and a magnetic recording head including an upper magnetic core having a end portion and a rear portion. As a resist for a frame which is used for forming the rear portion, a negative resist or an electron beam resist is used, whereby the frame is formed without any adverse effect of halation from a coil insulating film. That is, it is possible to manufacture a magnetic recording head in which the rear portion of an upper magnetic core is not emerged at the face opposed to a medium, and hence to obtain a magnetic disk apparatus exhibiting an areal recording density of 5 Gbit/in or more by mounting a magnetic recording/reproducing head including such a magnetic recording head.

The present invention is to realize a magnetic recording and reproducing apparatus in which even if a spacing between shields of a magnetic head is narrowed, a deterioration in characteristic caused by a short-circuiting between a magnetoresistive layer and a magnetic shield layer is prevented to provide a high recording density. The present invention comprises an upper shield layer a lower shield layer and a magnetoresistive layer arranged therebetween. Further, there is provided a constitution in which one or both shield layers has (have) a high resistance layer comprising a mixed layer of ferromagnetic metal and an insulating material, or a discontinuous multi-layer having a plurality of ferromagnetic metal layers and a plurality of insulating material layers laminated alternately, to prevent a deterioration in characteristic caused by a short-circuiting.

Magnetic head with shield layer having discontinuous multi-layer or mixed layer and magnetic recording apparatus utilizing the magnetic head

A thin film magnetic head having a first magnetic core, a second magnetic core formed on the first magnetic core, a coil disposed between the first magnetic core and second magnetic core, and a non-magnetic insulator body for separating the first magnetic core, second magnetic core and coil with respect to each other. At least one of the first magnetic core and the second magnetic core includes an electroplated thin film with an average crystal grain size smaller than 500 &angst; and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Thin film magnetic head and assembled construction thereof

A read-write head is capable of suppressing fluctuation on a reproduced waveform caused by repetition of a writing and reading operation, and is capable suppressing noise appearing in the reproduced waveform just after a writing operation is carried out. The read-write head has an upper magnetic core, an upper shield also serving as an lower magnetic core, a lower shield and a magnetoresistive film arranged between the upper shield and the lower shield. The upper shield has a soft magnetic film having a magnitude of anisotropy field of 5 to 30 Oe, or is a multilayer film composed of a high saturation magnetic flux density film and a negative magneto-striction film. The lower shield has a soft magnetic film having a magnitude of anisotropy field of 5 to 30 Oe.

Read-write head

A thin film magnetic head and a disk storage system having a magnetic disk and the thin film magnetic head provided on a floating type slider. The thin film magnetic head has an upper magnetic core and a lower magnetic core, wherein the upper magnetic core and the lower magnetic core are made of an electroplated thin film having sufficient average crystal grain size. The upper magnetic core is made of a Ni&mdash;Fe alloy having Ni of 38 to 60 wt % and Fe of 40 to 62 wt %, and the crystal grain size is smaller than 500 &angst;.

Thin film magnetic head with Ni-Fe alloy thin film

A magnetoresistive head in which Barkhausen noise is substantially suppressed and a variation in reproduction is minimized, and a magnetic disk apparatus using the same magnetic head have been provided. The feature of the magnetic head and the magnetic disk apparatus of the invention resides in the provision of the longitudinal bias layer which comprises a hard magnetic thin film formed on an underlayer made of either of a ferromagnetic thin film having a body-centered cubic lattice crystal structure formed of body-centered cells, an amorphous ferromagnetic thin film or antiferromagnetic thin film having a body-centered cubic lattice crystal structure formed of body-centered cells.

Magnetoresistive head and magnetic disk apparatus

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Hitachi, Japan

Takashi Kawabe