Patents by Inventor Masashi Sahashi

Masashi Sahashi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6784509
    Abstract: In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: August 31, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
  • Publication number: 20040121185
    Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.
    Type: Application
    Filed: October 10, 2001
    Publication date: June 24, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
  • Patent number: 6754053
    Abstract: A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: June 22, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Yoshikawa, Masashi Sahashi, Katsuhiko Koi, Hitoshi Iwasaki, Hiromi Yuasa, Hideaki Fukuzawa
  • Publication number: 20040114280
    Abstract: A magnetoresistive element has a magnetoresistive film and a pair of electrodes adapted to flow a sense current in a direction substantially perpendicular to a plane of the magnetoresistive film. The magnetoresistive film includes first and second magnetization free layers and first to fourth magnetization pinned layers with nonmagnetic intermediate layers interposed therebetween. The second magnetization pinned layer and the third magnetization pinned layer are formed between the second nonmagnetic intermediate layer and the third nonmagnetic intermediate layer. The directions of magnetization of the first and second magnetization pinned layers are substantially parallel to each other. The directions of magnetization of the third and fourth magnetization pinned layers are substantially parallel to each other. Further, the direction of magnetization of the second magnetization pinned layer is substantially antiparallel to the direction of magnetization of the third magnetization pinned layer.
    Type: Application
    Filed: September 5, 2003
    Publication date: June 17, 2004
    Inventors: Masatoshi Yoshikawa, Masayuki Takagishi, Masashi Sahashi
  • Patent number: 6690553
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness of the second portion being smaller than the film thickness of the first portion.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: February 10, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Publication number: 20040021990
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film including a magnetically pinned layer whose direction of magnetization is pinned substantially in one direction, a magnetically free layer whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic intermediate layer located between the pinned layer and the free layer; and a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film, The intermediate layer has a first layer including a first region whose resistance is relatively high and second regions whose resistance is relatively low. The sense current preferentially flows through the second regions when the current passes the first layer.
    Type: Application
    Filed: March 28, 2003
    Publication date: February 5, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Masatoshi Yoshikawa, Masayuki Takagishi, Masashi Sahashi, Takeo Sakakubo, Hitoshi Iwasaki
  • Patent number: 6676772
    Abstract: The magnetic material for magnetic refrigeration of the present invention is characterized by exhibiting, in a certain temperature region, preferably, only in part of a temperature region from 200 K to 350 K, an inflection point at which a second order differential coefficient of a magnetization curve changes from positive to negative with respect to a magnetic field, within the range of this magnetic field formed using a permanent magnet unit. This magnetic material of the present invention can generate a low temperature by using a relatively low magnetic field, by transferring the entropy between the electron spin system and the lattice system near the temperature at which an inflection point appears on the magnetization curve. Examples of the magnetic material meeting this condition are La(Fe,Si)13, (Hf,Ta)Fe2, (Ti,Sc)Fe2, and (Nb,Mo)Fe2, each containing 50 to 60 atomic % of transition metals such as Fe.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: January 13, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akiko Saito, Tadahiko Kobayashi, Takao Sawa, Masashi Sahashi
  • Publication number: 20030214742
    Abstract: A magnetic recording apparatus comprises a magnetic field impression unit, a current supplying unit and a controlling unit t. The magnetic field impression unit impresses a magnetic field to a magnetic recording medium. The current supplying unit supplies a current to the magnetic recording medium. The controlling unit makes the current supplying unit supply the current to the magnetic recording medium while making the magnetic field impression unit impress the magnetic field to at least a unit of a magnetic recording unit of the magnetic recording medium. Thus, a information is recorded magnetically by making a direction of a magnetization of the magnetic recording unit of the magnetic recording medium in a predetermined direction.
    Type: Application
    Filed: March 28, 2003
    Publication date: November 20, 2003
    Inventors: Tadashi Kai, Masayuki Takagishi, Masashi Sahashi, Junichi Akiyama, Hitoshi Iwasaki, Akira Kikitsu
  • Patent number: 6636399
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness-of the second portion being smaller than the film thickness of the first portion.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: October 21, 2003
    Assignee: Kabushiki Kaishia Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Publication number: 20030168673
    Abstract: In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.
    Type: Application
    Filed: August 14, 2002
    Publication date: September 11, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
  • Patent number: 6593841
    Abstract: Disclosed herein is a planar magnetic element comprising a substrate, a first magnetic layer arranged over the substrate, a first insulation layer arranged over the first magnetic layer, a planer coil formed of a conductor, having a plurality of turns, arranged over the first insulation layer and having a gap aspect ratio of at least 1, the gap aspect ratio being the ratio of the thickness of the conductor to the gap between any adjacent two of the turns, a second insulation layer arranged over the planar coil, and a second magnetic layer arranged over the second insulation layer. When used as an inductor, the planar magnetic element has a great quality coefficient Q. When used as a transformer, it has a large gain and a high voltage ratio. Since the element is small and thin, it is suitable for use in an integrated circuit, and can greatly contribute to miniaturization of electronic devices.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: July 15, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tetsuhiko Mizoguchi, Toshiro Sato, Masashi Sahashi, Michio Hasegawa, Hiroshi Tomita, Atsuhito Sawabe
  • Publication number: 20030051774
    Abstract: The magnetic material for magnetic refrigeration of the present invention is characterized by exhibiting, in a certain temperature region, preferably, only in part of a temperature region from 200 K to 350 K, an inflection point at which a second order differential coefficient of a magnetization curve changes from positive to negative with respect to a magnetic field, within the range of this magnetic field formed using a permanent magnet unit. This magnetic material of the present invention can generate a low temperature by using a relatively low magnetic field, by transferring the entropy between the electron spin system and the lattice system near the temperature at which an inflection point appears on the magnetization curve. Examples of the magnetic material meeting this condition are La(Fe,Si)13, (Hf,Ta)Fe2, (Ti,Sc)Fe2, and (Nb,Mo)Fe2, each containing 50 to 60 atomic % of transition metals such as Fe.
    Type: Application
    Filed: March 18, 2002
    Publication date: March 20, 2003
    Inventors: Akiko Saito, Tadahiko Kobayashi, Takao Sawa, Masashi Sahashi
  • Publication number: 20030011463
    Abstract: In a CPP element using a metal intermediate layer excellent in shot noise and response to high frequencies unlike a TMR element, its magnetoresistive effect film includes a magnetic layer mainly made of a half-metal exhibiting ferromagnetism, ferrimagnetism or antiferromagnetism, and largely variable in way of conduction in response to spin direction of electrons.
    Type: Application
    Filed: June 24, 2002
    Publication date: January 16, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hitoshi Iwasaki, Katsuhiko Koui, Masatoshi Yoshikawa, Hiromi Yuasa, Hideaki Fukuzawa, Masashi Sahashi
  • Publication number: 20030011945
    Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate value, thereby to increase the resistance variable amount.
    Type: Application
    Filed: June 21, 2002
    Publication date: January 16, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20020191354
    Abstract: A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.
    Type: Application
    Filed: March 29, 2002
    Publication date: December 19, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Yoshikawa, Masashi Sahashi, Katsuhiko Koi, Hitoshi Iwasaki, Hiromi Yuasa, Hideaki Fukuzawa
  • Patent number: 6495275
    Abstract: A magnetoresistance effect element includes a free layer, a pinned layer and a non-magnetic intermediate layer interposed between the free layer and the pinned layer. Additionally, a metal barrier layer is provided adjacent to the first magnetic layer. An electron reflecting layer located adjacent to the metal barrier layer contains at least one selected from oxides, nitrides, carbides, fluorides, chlorides, sulfides and borides.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: December 17, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Kamiguchi, Akiko Saito, Katsuhiko Koui, Masatoshi Yoshikawa, Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki, Hiroaki Yoda, Masashi Sahashi
  • Patent number: 6475302
    Abstract: Disclosed is a permanent magnet which comprises an alloy containing a hard magnetic phase having a ThMn12 type tetragonal structure and a nonmagnetic phase. The alloy is represented by a general formula given below: [R1-a(M1)a][T1-b-c(M2)b(M3)c]dx&agr; where R is at least one rare earth element (including Y), Ml is at least one element selected from the group consisting of Zr and Hf, T is at least one element selected from the group consisting of Fe, Co and Ni, M2 is at least one element selected from the group consisting of Cu, Bi, Sn, Mg, In and Pb, M3 is at least one element selected from the group consisting of Al, Ga, Ge, Zn, B, P and S, X is at least one element selected from the group consisting of Si, Ti, V, Cr, Mn, Nb, Mo, Ta and W, and the atomic ratios of a, b, c, d and &agr; fall within the ranges of 0≦a≦0.6, 0.01≦b≦0.20, 0≦c≦0.05, 6≦d≦11, and 0.5≦&agr;≦2.0.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: November 5, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wu Mei, Toshiya Sakamoto, Shinya Sakurada, Takao Sawa, Akihiko Tsutai, Akiko Saito, Masashi Sahashi
  • Publication number: 20020150791
    Abstract: A magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, a nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer, and electrodes allowing a sense current to flow in a direction substantially perpendicular to the plane of the stack including the magnetization pinned layer, the nonmagnetic intermediate layer and the magnetization free layer. At least one of the magnetization pinned layer and the magnetization free layer is substantially formed of a binary or ternary alloy represented by the formula FeaCobNic (where a+b+c=100 at %, and a≦75 at %, b≦75 at %, and c≦63 at %), or formed of an alloy having a body-centered cubic crystal structure.
    Type: Application
    Filed: February 1, 2002
    Publication date: October 17, 2002
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Yuzo Kamiguchi, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 6466122
    Abstract: A planar inductor has a spiral coil, insulating layers stacked on both surfaces of the spiral coil, and ferromagnetic layers stacked on the insulating layers, wherein each ferromagnetic layer has a saturation magnetization 4&pgr;Ms of 10 kG or more, and a thickness of 100 &mgr;m or less.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: October 15, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michio Hasegawa, Masashi Sahashi
  • Patent number: 6455178
    Abstract: An exchange coupling film comprises a ferromagnetic film and an antiferromagnetic film laminated on the ferromagnetic film, wherein at least a portion of the antiferromagnetic film has a face-centered cubic crystal structure and the antiferromagnetic film comprises an IrMn alloy represented by the general formula of IrxMn100−x, wherein x stands for a value by atomic % satisfying the expression, 2≦x≦80.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: September 24, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Yuuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Kazuhiro Saito, Hitoshi Iwasaki, Masashi Sahashi