Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Yoshiaki Kawato

Kazuhiro Nakamoto

Masafumi Mochizuki

Hiroyuki Hoshiya

Tomohiro Okada

Yasuyuki Okada

Katsuro Watanabe

Isao Nunokawa

Hiroshi Fukui

Matahiro Komuro

Kimitoshi Etoh

Atsushi Nakamura

Nobuo Yoshida

Reiko Arai

Kaori Suzuki

Masaaki Futamoto

Kenchi Ito

Hisashi Kimura

Hiroshi Ide

Yuko Tsuchiya

Hisashi Takano

Yasutaka Nishida

Kazue Kudo

Kenichi Meguro

Hiroyuki Katada

Takayuki Ichihara

Yoshihiro Hamakawa

Chiseki Haginoya

Yasuo Wakaki

In a magnetic head to be used for a shingled recording method, degradation of a signal resolution and a decrease in a signal-to-noise ratio which are caused by an asymmetrical inter-bit transition curvature are prevented, and a low bit error rate is realized. A magnetic head includes a recording head and a reproducing head. The reproducing head includes a pair of magnetic shields and a sensor sandwiched between the pair of magnetic shields. The gap between the magnetic shields is formed so that the longitudinal direction thereof gets inclined by a certain angle with respect to a cross-track direction in line with the shape of a curvature of an inter-bit transition on an effective record track in a record pattern recorded on a recording medium.

Magnetic head and magnetic disk drive to be used for shingled recording method

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

A read sensor is disposed near a main pole, thereby reducing the distance between the read sensor and a write sensor. In this case, however, a magnetic field generated from the main pole affects magnetization of a free layer and a pinned layer of a magnetoresistive film, thereby causing the magnetizing directions to rotate, a magnetic barrier to be generated, and the read property to be degraded. According to the present invention, a main pole and a yoke configure a magnetic circuit together with a sub-pole and a soft magnetic under layer of the magnetic disk and an exciting coil magnetizes the magnetic circuit, thereby a recording magnetic field is applied to a recording layer to record information bits on the layer. And in order to sharpen the magnetic field distribution generated by the main pole, a trailing shield made of a ferromagnetic material is disposed at the trailing side of the main pole adjacently. And a read sensor (magnetoresistive element) for reading bit information is provided between the trailing shield and the main pole.

Magnetic head and magnetic disk system having a read sensor and a sensing current

The disclosed invention provides a magnetic head of high stability in which 'erase after write' is prevented. Here is provided a magnetic head comprising a thin-film magnetic head for perpendicular magnetic recording, the thin-film magnetic head including a main pole with its tip facing a magnetic recording medium and coils for exciting the main pole, wherein the tip of or at least a part of the main pole consists of a soft magnetic multilayer containing laminations, each of which comprises a first ferromagnetic film, a second ferromagnetic film, and an antiparallel coupling layer formed between the first ferromagnetic film and the second ferromagnetic film, wherein the antiparallel coupling layer causes antiferromagnetic interlayer coupling of the first ferromagnetic film and the second ferromagnetic film.

Magnetic head

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

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

A perpendicular magnetic recording medium for thermo-magnetic printing has an ultra-high recording density and is resistant to thermal decay of magnetization. An intermediate layer of the medium is provided between a first recording layer using a low-noise Co alloy ferromagnetic substance and a second recording layer using a ferrimagnetic substance (e.g., a rare-earth element-transition metal compound) having a compensation temperature below an operation ambient temperature. A magnetic field is applied thereto to form a magnetization pattern on the first recording layer. It is then heated-up to be printed onto the second recording layer, which has a higher coercivity at the ambient temperature, and a recording field is suitably set to form a magnetization pattern only on the first recording layer. The magnetization pattern is printed from the first recording layer to the second recording layer.

Magneto-optical recording using a heating element

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.

Perpendicular magnetic recording head and perpendicular magnetic recording and reproducing system

A method of fabricating a thin film magnetic recording head including a perpendicular recording head having an auxiliary pole, a main pole and a shield against an external magnetic field. The shield against the external magnetic field is formed so that an edge of the shield against the external magnetic field is disposed at a position recessed at least from an edge of the main pole relative to a surface against a medium.

Method of fabricating a thin film magnetic recording head

Disclosed herein is a magnetic head for perpendicular recording in which the main magnetic pole has reduced remanent magnetization and is less liable to cause erasure after recording. These characteristic properties were realized by constructing the magnetic head such that the recording magnetic pole and the yoke are separate from each other and the main magnetic pole is formed from a material with a high saturation magnetic flux density and the yoke is formed from a material having a negative magnetostriction constant.

Magnetic head and magnetic storage apparatus

The invention provides a magnetic head for perpendicular recording capable of recording with high linear recording density and high track density, and a magnetic disk drive incorporating the same. In order to achieve this, one or more sides of the main pole of the magnetic head for perpendicular recording except for the trailing side are formed in a taper with an appropriate angle against the tip surface of the main pole, and the yoke whose widest principal plane is in parallel to the tip surface is provided on the bottom of the main pole. Thereby, the invention achieves the magnetic head for perpendicular recording that generates a sufficiently high magnetic field, and assumes a sharp gradient of magnetic field on the trailing side. By incorporating this magnetic head, a magnetic disk drive capable of handling high linear recording density can be produced.

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Tokyo, Japan

Yoshiaki Kawato