Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Metals, Ltd.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies

Kazuhiro Nakamoto

Yoshiaki Kawato

Hiroyuki Hoshiya

Yasuyuki Okada

Kenichi Meguro

Masafumi Mochizuki

Katsuro Watanabe

Hisashi Kimura

Nobuo Yoshida

Takashi Kawabe

Chiaki Ishikawa

Hiromasa Takahashi

Yasunori Abe

Hiroshi Fukui

Masaaki Futamoto

Kimitoshi Etoh

Hiroyuki Katada

Chiseki Haginoya

Masahiko Hatatani

Kaori Totsuka

Makoto Saito

Moriaki Fuyama

Masato Shiimoto

Masayuki Kurita

Kazue Kudo

Shinji Narishige

Takao Imagawa

Mikito Sugiyama

Katsumi Hoshino

Tetsuo Kobayashi

Tadayuki Iwakura

Masaaki Sano

Katsuya Mitsuoka

Kaori Suzuki

Masanori Tanabe

Makoto Aihara

Kenichi Meguroo

Shun-ichi Marumi

You Sato

Shuji Sudo

Chiaki Ishakawa

Embodiments of the present invention help to reduce mag-noise in a magnetoresistive head without deterioration in reproduced output and improve the signal/noise ratio (SNR) of the magnetoresistive head. According to one embodiment, the magnetoresistive head uses a synthetic ferri free layer and it is arranged such that the magnetic field which is applied to an end of a free layer with smaller film thickness and saturation magnetization in the track width direction by a coupling field is larger than the magnetic field which is applied to it by a bias layer.

Magnetic head using a synthetic ferri free structure

There is provided an angle sensor and angle detection device of high output and high accuracy with a wide operating temperature range. First through eighth sensor unitsandare produced from spin valve magnetoresistive films that use a self-pinned type ferromagnetic pinned layer comprising two layers of ferromagnetic films that are strongly and anti-ferromagnetically coupled. The respective sensor units are produced via the formation and patterning of thin-films magnetized at angles that differ by 90&#xb0;, and the formation of insulation films. By using, for the ferromagnetic films, CoFe and FeCo films that have similar Curie temperatures to make the difference in magnetization amount be zero, high immunity to external magnetic fields, a broad adaptive temperature range, and high output are realized.

Angle sensor, angle sensor manufacturing method, and angle detection device using the angle sensor

According to one embodiment, a perpendicular magnetic recording head includes a main pole, wherein a thickness in a down-track direction of the main pole increases moving away from an air bearing surface of the magnetic pole, and wherein a center position in a thickness direction of a portion of the main pole which is exposed at the air bearing surface (the ABS portion) is positioned toward a trailing side of the main pole with respect to a center position in a thickness direction of a portion of the magnetic pole having a greatest cross-sectional area and which is set back from the air bearing surface (the set-back portion). Further embodiments of this magnetic recording head, along with systems thereof and methods of producing magnetic recording heads are also described, according to more embodiments.

Perpendicular magnetic recording head and method for producing the same

Embodiments of the present invention help to provide a single element type differential magnetoresistive magnetic head capable of achieving high resolution and high manufacturing stability. According to one embodiment, a magnetoresistive layered film is formed by stacking an underlayer film, an antiferromagnetic film, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a long distance antiparallel coupling layered film, and a differential soft magnetic free layer. The long distance antiparallel coupling layered film exchange-couples the soft magnetic free layer and the differential soft magnetic free layer in an antiparallel state with a distance of about 3 nanometers through 20 nanometers. By manufacturing the single element type differential magnetoresistive magnetic head using the magnetoresistive layered film, it becomes possible to achieve the high resolution and the high manufacturing stability without spoiling the GMR effect.

Differential magnetoresistive magnetic head

Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.

Thin film perpendicular magnetic recording head, their fabrication process and magnetic disk drive using it

Embodiments of the invention secure a sufficiently large magnetic field, and deter a protrusion phenomenon of a perpendicular magnetic recording head, causing a problem in implementing a low flying height, while solving problems such as erasure of information in peripheral tracks. In one embodiment, a main pole or a stacked body made up of the main pole, and an auxiliary pole is deposited over an underlayer formed on a substrate so as to be in contact with the underlayer. On top of the main pole or the stacked body, there is deposited a coil, a return pole, and a read element in that order, thereby fabricating a perpendicular magnetic recording head. Further, an additional structure may be added such that an underlayer containing a metal is disposed between the substrate, and the main pole or the stacked body made up of the main pole, and the auxiliary pole, and a heat diffusion layer is disposed between portions of the coil and the substrate, or portions of the coil is disposed closer to the substrate than other portions of the coil.

Perpendicular recording head with reduced thermal protrusion

Embodiments of the invention provide a magnetic recording and read head which reduces the spread read width in a narrow track having a width of 100 nm or less and shows stable read operation. In one embodiment, a side magnetic shield has a multi-layered structure including non-magnetic separate layers and soft magnetic layers, and the soft magnetic layers are magnetized in opposite directions to reduce a magnetic field induced by the side magnetic shield.

Magnetic head with laminated side shields

In a side shield structure employed to narrow the effective track, a noise caused by the side shield structure can be reduced. In one embodiment, the side shield is inclined with respect to the film plane to suppress the generation of a magnetic pole in the end portion of the side shield. To this end, the side face of a device is inclined at a desired angle. Further, a reproduction device is formed at two or more angles &#x3b2;and &#x3b2;to improve the track width accuracy.

Magnetic head with side shield and manufacturing method thereof

To provide a magnetic encoder having high resolution and a high output, and a magnetoresistive sensor for an encoder. A fine sensor having a reduced demagnetization field is produced by: forming a free layer consists of a laminated soft magnetic film in which two soft magnetic layers are coupled in anti-parallel, and setting the width of a sensor unit to 2 &#x3bc;m to 4 &#x3bc;m.

Magnetic encoder apparatus

There is provided a perpendicular magnetic recording and reproducing system in which the overwrite erase ratio of a perpendicular magnetic head has been improved to prevent the deterioration of an overwrite property. In the perpendicular magnetic head, a third magnetic pole composed of a soft magnetic layer is formed on the leading side of a recording magnetic pole via a non-magnetic layer, thereby reducing magnetic interference from magnetization on a medium with the recording magnetic pole and preventing the deterioration of the overwrite property.

Perpendicular magnetic recording and reproducing head

The present invention provides a magnetic sensor suitable for high resolution and having high reliability by achieving stable output even at the occurrence of variations in a gap between a magnetic medium and the magnetic sensor, and a magnetic encoder using the magnetic sensor. The present invention uses a magnetoresistive element having magnetoresistive properties that satisfy the inequation, H10&#x2212;50&#x3c;H50&#x2212;90, where H10&#x2212;50 represents a magnetic field required for a resistance change from &#x394;R&#xd7;10% to &#x394;R&#xd7;50% with respect to a maximum amount of resistance change &#x394;R on a magnetoresitance effect curve, and H50&#x2212;90 represents a magnetic field required for a resistance change from &#x394;R&#xd7;50% to &#x394;R&#xd7;90%.

Magnetic encoder having a stable output property with unsaturated magnetic sensor

An improved perpendicular magnetic recording medium and an improved magnetic storage apparatus are provided, which are suitable for high speed and high density magnetic recording. A magnetic under layer of a two-layered perpendicular magnetic recording medium includes three layers: a ferromagnetic layer; a non-magnetic layer; and a ferromagnetic layer, wherein the ferromagnetic layers are antiferromagnetically coupled with each other, thereby preventing a magnetic flux from a magnetic wall in a magnetic under layer from entering a read back head.

Perpendicular magnetic recording medium and magnetic storage apparatus

Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field exceeding 10 kOe while suppressing remanent magnetic fields occurring immediately after write operations. The perpendicular magnetic head comprises a main pole, a return path for supplying a magnetic flux to that main pole, and a conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer has a thickness within 0.5 to 5 nanometers, and The high saturation flux density layer has a thickness from 10 to 50.

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Odawara, Japan

Kazuhiro Nakamoto