Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Maxell, Limited

Hitachi Global Storage Technologies

Masahiro Kitada

Noboru Shimizu

Hideo Tanabe

Naoki Koyama

Hisashi Takano

Isamu Yuito

Toshio Kobayashi

Mikio Suzuki

Ryoichi Nakatani

Kazuo Shiiki

Masaaki Futamoto

Yoshibumi Matsuda

Kyo Akagi

Takeshi Nakao

Yoshinori Miyamura

Fumio Kugiya

Eijin Moriwaki

Hirotsugu Fukuoka

Takayuki Munemoto

Tokuho Takagaki

Tooru Takeura

Hitoshi Nakamura

Yoshihisa Kamo

Kazuhiro Momata

Makoto Morijiri

Tetsuo Kobayashi

Yoshihiro Hamakawa

Masahide Suenaga

Masao Katsumata

Hiroshi Yamamoto

Yuzuru Hosoe

Hideo Fujiwara

Kanji Kawakami

Sadao Hishiyama

Naoki Sato

Yasutaro Uesaka

Hiroshi Tsuchiya

Yukihisa Tsukada

Kazuyoshi Adachi

Toshikane Yoshimatsu

Isamu Yuitoo

Katsunori Ohwada

Shigeyoshi Kato

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetic apparatus with perpendicular recording medium and head having multilayered reproducing element using tunneling effect

Method for manufacturing magnetic head device

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetic head with conductors formed on endlayers of a multilayer film having magnetic layer coercive force difference

Magnetic disk apparatus including magnetic head having multilayered reproducing element using tunneling effect

The proposed magnetic storage apparatus has the following features. The frequency at which data is recorded is selected to be 45 MHz. The thickness, resistivity and relative permeability of the magnetic film of which the magnetic poles of the magnetic head used in the apparatus are made are designed considering the eddy current loss. Also, the relation of &mgr;d /&rgr;&lE;500 is satisfied where d (&mgr;m) is the thickness of the magnetic film of which the magnetic poles of the magnetic head are made, &rgr; (&mgr;&OHgr;-cm) is the resistivity, and &mgr; is the relative permeability in a low-frequency range. Under these conditions, the amount of attenuation of recording magnetic field is reduced to 10% or below, and problems of writing blur and overwrite value variation which occur as the recording frequency changes can be solved. Moreover, the media data rate is 15 megabytes per sec., and the areal data-recording density is 500 megabits per square inch or more.

Magnetic storage apparatus

The proposed magnetic storage apparatus has the following features. The frequency at which data is recorded is selected to be 45 MHz. The thickness, resistivity and relative permeability of the magnetic film of which the magnetic poles of the magnetic head used in the apparatus are made are designed considering the eddy current loss. Also, the relation of &mgr;d,/&rgr;&lE;500 is satisfied where d (&mgr;m) is the thickness of the magnetic film of which the magnetic poles of the magnetic head are made, &rgr;(&mgr;&OHgr;-cm) is the resistivity, and &mgr;is the relative permeability in a low-frequency range. Under these conditions, the amount of attenuation of recording magnetic field is reduced to 10% or below, and problems of writing blur and overwrite value variation which occur as the recording frequency changes can be solved. Moreover, the media data rate is 15 megabytes per sec., and the areal data-recording density is 500 megabits per square inch or more.

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semicondutor or an antiferromagnetic material against the magnetic layers, and the magneto-resistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetoresistance effect elements and magnetic heads using the tunneling magnetoresistive effect

The proposed magnetic storage apparatus has the following features. The frequency at which data is recorded is selected to be 45 MHz. The thickness, resistivity and relative permeability of the magnetic film of which the magnetic poles of the magnetic head used in the apparatus are made are designed considering the eddy current loss. Also, the relation of .mu.d.sup.2 /.rho..ltoreq.500 is satisfied where d (.mu.m) is the thickness of the magnetic film of which the magnetic poles of the magnetic head are made, .rho. (.mu..OMEGA.-cm) is the resistivity, and .mu. is the relative permeability in a low-frequency range. Under these conditions, the amount of attenuation of recording magnetic field is reduced to 10% or below, and problems of writing blur and overwrite value variation which occur as the recording frequency changes can be solved. Moreover, the media data rate is 15 megabytes per sec., and the areal data-recording density is 500 megabits per square inch or more.

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-denisity recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetoresistance effect multilayer film with ferromagnetic film

A magnetoresistive element uses a multilayer film where ferromagnetic layers and nonferromagnetic layers are layered on each other, wherein a permanent magnet layer is formed on the aforementioned multilayer film through one of the nonferromagnetic layers and a bias field is applied on the multilayer film.

Multilayer which shows magnetoresistive effect and magnetoresistive

A magnetoresistance effect reproduction head which comprises a magnetoresistive layer having a central sensing region and an end domain control region and formed into a thin film of a ferromagnetic material, a hard magnetic layer overlapping with the end domain control region in direct contact therewith and formed into a thin film of a hard magnetic material, a magnetic field and a longitudinal magnetic bias field by ferromagnetic exchange coupling is generated for maintaining the central sensing region of the magnetoresistive layer in single domain state.

Magnetoresistance effect reproduction head

Multilayer magnetoresistance effect-type magnetic head

In an inductive-write, magnetoresistive-read type magnetic head having a magnetoresistive read head and an inductive write head superimposed on each other, the magnetic center of the read head is made more coincident with the physical center of the write head by a changing of a magnetization direction of a magnetoresistive element. The recording/reproducing apparatus using this magnetic head can thus have a good S/N ratio even if the track width is narrow.

Magnetic head and recording and reproducing apparatus having an

In a magnetic head whose recording and reproduction sections are separated, the magnetoresistive element constituting the reproduction head has a structure comprising a soft magnetic film, a spacer metallic film, and a magnetoresistive film and uses a high-performance soft magnetic film whose composition is Ni--Fe--Ru, Ni--Fe--Ru--M (M: fourth element), Ni--Fe--Ta or Ni--Fe--Ta--M (M: fourth element) and which has low coercivity, low magnetostriction, high specific resistance, high saturation magnetization, low magnetoresistivity and high corrosion resistance, this invention provides a recording-reproduction separation type magnetic head comprising a soft magntic bias film which is high magnetic performance, low production cost, and high corrosion resistance.

Magnetoresistive head

Growing community of inventors

Tokyo, Japan

Masahiro Kitada