Patents by Inventor Nozomu Matsukawa

Nozomu Matsukawa 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: 6567246
    Abstract: A magnetoresistance effect element includes a free layer, in which a magnetization direction thereof is easily rotated in response to an external magnetic field, a first non-magnetic layer, and a first pinned layer provided on a side opposite to the free layer of the first non-magnetic layer, in which a magnetization direction of the first pinned layer is not easily rotated in response to the external magnetic field. At least one of the first pinned layer and the free layer includes a first metal magnetic film contacting the first non-magnetic layer, and a first oxide magnetic film.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: May 20, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Yasunari Sugita, Mitsuo Satomi, Yasuhiro Kawawake, Masayoshi Hiramoto, Nozomu Matsukawa
  • Patent number: 6555889
    Abstract: A magnetoresistive device including a high-resistivity layer (13), a first magnetic layer (12) and a second magnetic layer (14), the first magnetic layer (12) and the second magnetic layer (14) being arranged so as to sandwich the high-resistivity layer (13), wherein the high-resistivity layer (13) is a barrier for passing tunneling electrons between the first magnetic layer (12) and the second magnetic layer (14), and contains at least one element LONC selected from oxygen, nitrogen and carbon; at least one layer A selected from the first magnetic layer (12) and the second magnetic layer (14) contains at least one metal element M selected from Fe, Ni and Co, and an element RCP different from the metal element M; and the element RCP combines with the element LONC more easily in terms of energy than the metal element M. Accordingly, a novel magnetoresistive device having a low junction resistance and a high MR can be obtained.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: April 29, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima, Hideaki Adachi, Akihiro Odagawa
  • Patent number: 6528326
    Abstract: A magnetoresistive device including a high-resistivity layer (13), a first magnetic layer (12) and a second magnetic layer (14), the first magnetic layer (12) and the second magnetic layer (14) being arranged so as to sandwich the high-resistivity layer (13), wherein the high-resistivity layer (13) is a barrier for passing tunneling electrons between the first magnetic layer (12) and the second magnetic layer (14), and contains at least one element LONC selected from oxygen, nitrogen and carbon; at least one layer A selected from the first magnetic layer (12) and the second magnetic layer (14) contains at least one metal element M selected from Fe, Ni and Co, and an element RCP different from the metal element M; and the element RCP combines with the element LONC more easily in terms of energy than the metal element M. Accordingly, a novel magnetoresistive device having a low junction resistance and a high MR can be obtained.
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: March 4, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima, Hideaki Adachi, Akihiro Odagawa
  • Publication number: 20030017723
    Abstract: A magnetoresistive device including a high-resistivity layer (13), a first magnetic layer (12) and a second magnetic layer (14), the first magnetic layer (12) and the second magnetic layer (14) being arranged so as to sandwich the high-resistivity layer (13), wherein the high-resistivity layer (13) is a barrier for passing tunneling electrons between the first magnetic layer (12) and the second magnetic layer (14), and contains at least one element LONC selected from oxygen, nitrogen and carbon; at least one layer A selected from the first magnetic layer (12) and the second magnetic layer (14) contains at least one metal element M selected from Fe, Ni and Co, and an element RCP different from the metal element M; and the element RCP combines with the element LONC more easily in terms of energy than the metal element M. Accordingly, a novel magnetoresistive device having a low junction resistance and a high MR can be obtained.
    Type: Application
    Filed: August 19, 2002
    Publication date: January 23, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima, Hideaki Adachi, Akihiro Odagawa
  • Patent number: 6436526
    Abstract: A magneto-resistive effect element includes a first ferromagnetic film; a second ferromagnetic film; and a first nonmagnetic film interposed between the first ferromagnetic film and the second ferromagnetic film. The first ferromagnetic film has a magnetization more easily rotatable than a magnetization of the second ferromagnetic film by an external magnetic field. The first ferromagnetic film has an effective magnetic thickness of about 2 nm or less.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: August 20, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiro Odagawa, Hiroshi Sakakima, Masayoshi Hiramoto, Nozomu Matsukawa
  • Patent number: 6433958
    Abstract: A magnetic head includes a pair of magnetic core halves; and a nonmagnetic layer provided between the pair of magnetic core halves for combining the pair of magnetic core halves. The pair of magnetic core halves each includes an oxide magnetic base, at least one underlying layer provided on the oxide magnetic base, and a metal magnetic thin film provided between the underlying film and the nonmagnetic layer. The metal magnetic thin film includes a magnetic film containing, as a major material, magnetic crystalline particles having an average volume Va and an average surface area Sa fulfilling the relationship of Sa>about 4.84 Va⅔. At least one of the pair of magnetic core halves has a winding window therein. The metal magnetic thin film is provided in such a manner as to prevent the oxide magnetic base from cracking due to an internal stress generated in the metal magnetic thin film.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: August 13, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nozomu Matsukawa, Masayoshi Hiramoto, Hiroshi Sakakima, Koichi Osano, Eisuke Sawai
  • Publication number: 20020106448
    Abstract: A magnetic head includes a pair of magnetic core halves; and a nonmagnetic layer provided between the pair of magnetic core halves for combining the pair of magnetic core halves. The pair of magnetic core halves each includes an oxide magnetic base, at least one underlying layer provided on the oxide magnetic base, and a metal magnetic thin film provided between the underlying film and the nonmagnetic layer. The metal magnetic thin film includes a magnetic film containing, as a major material, magnetic crystalline particles having an average volume Va and an average surface area Sa fulfilling the relationship of Sa>about 4.84 Va⅔. At least one of the pair of magnetic core halves has a winding window therein. The metal magnetic thin film is provided in such a manner as to prevent the oxide magnetic base from cracking due to an internal stress generated in the metal magnetic thin film.
    Type: Application
    Filed: December 28, 2001
    Publication date: August 8, 2002
    Inventors: Nozomu Matsukawa, Masayoshi Hiramoto, Hiroshi Sakakima, Koichi Osano, Eisuke Sawai
  • Publication number: 20020084501
    Abstract: A magnetoresistive device including a high-resistivity layer (13), a first magnetic layer (12) and a second magnetic layer (14), the first magnetic layer (12) and the second magnetic layer (14) being arranged so as to sandwich the high-resistivity layer (13), wherein the high-resistivity layer (13) is a barrier for passing tunneling electrons between the first magnetic layer (12) and the second magnetic layer (14), and contains at least one element LONC selected from oxygen, nitrogen and carbon; at least one layer A selected from the first magnetic layer (12) and the second magnetic layer (14) contains at least one metal element M selected from Fe, Ni and Co, and an element RCP different from the metal element M; and the element RCP combines with the element LONC more easily in terms of energy than the metal element M. Accordingly, a novel magnetoresistive device having a low junction resistance and a high MR can be obtained.
    Type: Application
    Filed: January 3, 2002
    Publication date: July 4, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima, Hideaki Adachi, Akihiro Odagawa
  • Publication number: 20020067581
    Abstract: A magneto-resistive element includes a vertical current type magneto-resistive element; a first conductor for causing a current to flow into the vertical current type magneto-resistive element; and a second conductor for causing the current to flow out of the vertical current type magneto-resistive element. The first conductor generates a first magnetic field based on the current. The second conductor generates a second magnetic field based on the current. The first conductor and the second conductor are located so that the first magnetic field and the second magnetic field act as a bias magnetic field applied on the vertical current type magneto-resistive element.
    Type: Application
    Filed: October 2, 2001
    Publication date: June 6, 2002
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Akihiro Odagawa, Kenji Iijima, Hiroshi Sakakima
  • Publication number: 20020058158
    Abstract: A magneto-resistive effect element includes a first ferromagnetic film; a second ferromagnetic film; and a first nonmagnetic film interposed between the first ferromagnetic film and the second ferromagnetic film. The first ferromagnetic film has a magnetization more easily rotatable than a magnetization of the second ferromagnetic film by an external magnetic field. The first ferromagnetic film has an effective magnetic thickness of about 2 nm or less.
    Type: Application
    Filed: December 28, 2001
    Publication date: May 16, 2002
    Inventors: Akihiro Odagawa, Hiroshi Sakakima, Masayoshi Hiramoto, Nozomu Matsukawa
  • Publication number: 20020044391
    Abstract: A magneto-resistive element includes a magnetic substrate; a magnetic layer; and a non-magnetic layer provided between the magnetic substrate and the magnetic layer.
    Type: Application
    Filed: November 8, 2001
    Publication date: April 18, 2002
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Akihiro Odagawa, Hideaki Adachi, Kenji Iijima, Hiroshi Sakakima
  • Publication number: 20020036872
    Abstract: The present invention provides a magnetic head having improved characteristics, using a magnetoresistive device in which current flows across the film plane such as a TMR device. In a first magnetic head of the present invention, when the area of a non-magnetic layer is defined as a device cross-section area, and the area of a yoke is defined as a yoke area, viewed along the direction perpendicular to the surface of the substrate over which the yoke and the magnetoresistive device are formed, then the device cross-section area is not less than 30% of the yoke area, so that a resistance increase of the device cross-section area is suppressed. In a second magnetic head of the present invention, a magnetoresistive device is formed on a substrate, and a yoke is provided above a non-magnetic layer constituting the device.
    Type: Application
    Filed: April 9, 2001
    Publication date: March 28, 2002
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Akihiro Odagawa, Kenji Iijima, Hiroshi Sakakima
  • Publication number: 20010026466
    Abstract: A magnetic control device including an antiferromagnetic layer, a magnetic layer placed in contact with one side of the antiferromagnetic layer, and an electrode placed in contact with another side of the antiferromagnetic layer, wherein the direction of the magnetization of the magnetic layer is controlled by voltage applied between the magnetic layer and the electrode. In particular, when an additional magnetic layer is further laminated on the magnetic layer placed in contact with the antiferromagnetic layer via a non-magnetic layer, the direction of the magnetization of the controlled magnetic layer can be detected as a change in the electric resistance. Since such a magnetic control device, in principle, responds to the electric field or magnetic field, it forms a magnetic component capable of detecting an electric signal or a magnetic signal. In this case, the direction of the magnetization basically is maintained until the next signal is detected, so that such a device also can form an apparatus.
    Type: Application
    Filed: March 9, 2001
    Publication date: October 4, 2001
    Applicant: Matsushita Electric Industrial Co. Ltd.
    Inventors: Hideaki Adachi, Akihiro Odagawa, Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima
  • Patent number: 6231968
    Abstract: The present invention provides a soft magnetic thin film having high reliability that is useful in a magnetic device such as a magnetic head, where the degradation of heat stability due to a high saturation magnetic flux density of the soft magnetic thin film, the degradation of resistance against surroundings and substrate breakage are suppressed. The magnetic thin film of the present invention comprises a magnetic film comprising approximately columnar, needle or branched magnetic crystal grains as a mother phase, which is formed by sputtering or the like. The magnetic crystal grains have an average maximum length more than 50 nm, and an average crystal size in a short direction of the approximately columnar or needle shape is more than 5 nm and less than 60 nm.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: May 15, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima
  • Patent number: 6110609
    Abstract: A magnetic thin film includes magnetic crystal grains and a region where an average crystal size of the magnetic crystal grains along a first direction is smaller than an average crystal size of the magnetic crystal grains along a second direction that is orthogonal to the first direction. Magnetization along the first direction is effected by an external magnetic field that is smaller than an external magnetic field for magnetization along the second direction. Thus, excellent characteristics in a high frequency can be obtained.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: August 29, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Nozomu Matsukawa, Hiroshi Sakakima