Patents by Inventor Akihiro Odagawa

Akihiro Odagawa 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).

  • 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
  • Publication number: 20020191355
    Abstract: The present invention provides a magnetoresistive element that includes a pair of magnetic layers and an intermediate layer between the magnetic layers. The intermediate layer contains at least three elements selected from Groups 2 to 17, and the elements include at least one selected from the group consisting of F, O, N, C and B. According to the invention, a magnetoresistive element with high magnetoresistance change ratio and low resistance can be provided. The invention also provides a method for producing a magnetoresistive element. The method includes forming a precursor and forming at least one part of the intermediate layer from the precursor. The precursor is reacted with at least one reactive species selected from the group consisting of oxygen atoms, nitrogen atoms and carbon atoms in a reactive atmosphere containing the reactive species.
    Type: Application
    Filed: January 18, 2002
    Publication date: December 19, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd
    Inventors: Masayoshi Hiramoto, Akihiro Odagawa, Nozomu Matukawa, Kenji Iijima, Hiroshi Sakakima
  • 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
  • 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: 20020055016
    Abstract: The present invention provides a vertical current-type magneto-resistive element. The element includes an intermediate layer and a pair of magnetic layers sandwiching the intermediate layer, and at least one of a free magnetic layer and a pinned magnetic layer is a multilayer film including at least one non-magnetic layer and magnetic layers sandwiching the non-magnetic layer. The element area defined by the area of the intermediate layer through which current flows perpendicular to the film is not larger than 1000 &mgr;m2.
    Type: Application
    Filed: August 16, 2001
    Publication date: May 9, 2002
    Inventors: Masayoshi Hiramoto, Nozomu Matukawa, Akihiro Odagawa, Kenji Iijima, Hiroshi Sakakima
  • 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: 20020036876
    Abstract: The invention increases the electric resistance of CPP-GMR elements to a practical range. Moreover, the invention presents a CPP-GMR element and a TMR element that can be applied to track widths that are made narrower due to higher densities of the magnetic recording. The area S1 of a non-magnetic layer 7 is 1 &mgr;m or less, and at least one layer selected from a first magnetic layer 6, a second magnetic layer 8 and the non-magnetic layer 7 includes a first region 30 through which current flows and a second region 20 made of an oxide, a nitride or an oxynitride of the film constituting that first region. The area S2 of the first region is smaller than the area of the non-magnetic layer. At least one of the layers of the element is oxidized, nitrided or oxynitrided from a lateral side.
    Type: Application
    Filed: September 4, 2001
    Publication date: March 28, 2002
    Inventors: Yasuhiro Kawawake, Yasunari Sugita, Akihiro Odagawa, Akihisa Yoshida, Hiroshi Sakakima
  • Publication number: 20020030945
    Abstract: The present invention provides a magnetoresistive element in which discontinuity at a barrier layer interface is provided by utilizing a layered-perovskite oxide, and a device in which the foregoing magnetoresistive element is used. The element of the present invention includes a layered-perovskite oxide having a composition expressed by a formula L2(A1−zRz)2An−1MnO3n+3+x and including a (L-O)2 layer in its crystalline structure, and a pair of ferromagnetic bodies formed in contact with the layer perovskite oxide so as to sandwich the oxide. In response to bias application via the (L-O)2 layer, a magnetoresistive tunnel effect appears.
    Type: Application
    Filed: May 23, 2001
    Publication date: March 14, 2002
    Inventors: Akihiro Odagawa, Hideaki Adachi, Masayoshi Hiramoto, Nozomu Matukawa, 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
  • Publication number: 20010021124
    Abstract: A magneto-resistive device and a magneto-resistive effect type storage device are provided, which have improved selectivity and output signals by controlling bias to be applied. Two resistive devices are connected in series, and a magneto-resistive device is used for at least one of the resistive devices. When both of the resistive devices are magneto-resistive devices, their magnetic resistance should be controlled independently from each other, and by allowing the first magneto-resistive device to include a nonmagnetic substance of an electrical insulator and the second magneto-resistive device to include a nonmagnetic substance of a conductive substance, the second magneto-resistive device is operated as a bias control device for controlling the characteristics of the first magneto-resistive device so as to control the voltage to be applied to the storage device.
    Type: Application
    Filed: March 13, 2001
    Publication date: September 13, 2001
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiro Odagawa, Hiroshi Sakakima, Kiyoyuki Morita
  • Patent number: 6160266
    Abstract: This invention provides a superconducting device with good characteristics that can be reproduced at an arbitrary place on a substrate and a method of manufacturing the same. A convex region (a processed, linearly shaped platinum thin film) of oriented metal is provided on a substrate as a gate electrode. Then, an oxide insulating film (SrTiO.sub.3 thin film) is deposited on the convex region, and further a YBa.sub.2 Cu.sub.3 O.sub.7 oxide superconducting thin film is deposited on the oxide insulating film. Accordingly, a grain boundary part is formed on the convex region. A drain electrode and a source electrode are formed facing each other with the grain boundary part between.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: December 12, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiro Odagawa, Hideaki Adachi, Kentaro Setsune
  • Patent number: 6147360
    Abstract: This invention provides a superconducting device with good characteristics that can be reproduced at an arbitrary place on a substrate and a method of manufacturing the same. A convex region (a processed, linearly-shaped platinum thin film) of oriented metal is provided on a substrate as a gate electrode. Then, an oxide insulating film (SrTiO.sub.3 thin film) is deposited on the convex region, and further a YBa.sub.2 Cu.sub.3 O.sub.7 oxide superconducting thin film is deposited on the oxide insulating film. Accordingly, a grain boundary part is formed on the convex region. A drain electrode and a source electrode are formed facing each other with the grain boundary part in between.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: November 14, 2000
    Assignee: Matsushita Electric Industrial Co. Ltd.
    Inventors: Akihiro Odagawa, Hideaki Adachi, Kentaro Setsune
  • Patent number: 6074768
    Abstract: A process for forming a laminate of 123-type copper oxide superconductor thin films having dissimilar crystal axis orientations, a laminate of 123-type thin copper oxide superconductor layers exhibiting excellent superconducting property, and wiring for Josephson junction. A c-axis oriented single crystalline thin film of an oxide superconductor having a Y:Ba:Cu atomic ratio of substantially 1:2:3 and a lattice constant of 11.60 angstroms.ltoreq.c.ltoreq.11.70 angstroms at a temperature of 20.degree. C. under an oxygen partial pressure of 160 Torr is formed on a single crystalline substrate, and an a-axis oriented single crystalline thin film of said oxide superconductor is formed on the above laminated film relying upon a sputter deposition method.
    Type: Grant
    Filed: December 16, 1998
    Date of Patent: June 13, 2000
    Assignee: Kyocera Corporation
    Inventors: Yoshinori Matsunaga, Shuichi Fujino, Akihiro Odagawa, Youichi Enomoto
  • Patent number: 5885939
    Abstract: A process for forming a laminate of 123-type copper oxide superconductor thin films having dissimilar crystal axis orientations, a laminate of 123-type thin copper oxide superconductor layers exhibiting excellent superconducting property, and wiring for Josephson junction. A c-axis oriented single crystalline thin film of an oxide superconductor having a Y:Ba:Cu atomic ratio of substantially 1:2:3 and a lattice constant of 11.60 angstroms.ltoreq.c.ltoreq.11.70 angstroms at a temperature of 20.degree. C. under an oxygen partial pressure of 160 Torr is formed on a single crystalline substrate, and an a-axis oriented single crystalline thin film of said oxide superconductor is formed on the above laminated film relying upon a sputter deposition method.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: March 23, 1999
    Assignees: Kyocera Corporation, International Superconductivity Technology Center, Matsushita Electric Industrial Co., Ltd., Mitsubishi Materials Corporation
    Inventors: Yoshinori Matsunaga, Shuichi Fujino, Akihiro Odagawa, Youichi Enomoto
  • Patent number: 5885937
    Abstract: This invention provides a superconducting tunnel junction element showing satisfactory Josephson effect. The element includes a Bi-based layered compound such as Bi.sub.2 Sr.sub.2 (Ca.sub.0.6 Y.sub.0.4)Cu.sub.2 O.sub.8, Bi.sub.2 Sr.sub.2 Cu.sub.2 O.sub.6 and Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8 as the barrier layer between the superconducting oxide electrodes. The structural matching of the superconducting oxide with the Bi-based compound is supposed to be good. Some kinds of Cu-based superconducting oxides such as YSr.sub.2 Cu.sub.2.7 Re.sub.0.3 O.sub.7, Sr.sub.2 CaCu.sub.2 O.sub.6 and (La.sub.0.9 Sr.sub.0.1).sub.2 CuO.sub.4 are used for the electrodes to obtain a Josephson element which can work at a high temperature. When using the superconducting oxides including Ba such as YBa.sub.2 Cu.sub.3 O.sub.7 for the electrode, forming a thin film between the electrode and the barrier is better to prevent Ba from reacting with Bi in the barrier layer.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: March 23, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideaki Adachi, Masahiro Sakai, Akihiro Odagawa, Kentaro Setsune
  • Patent number: 5719105
    Abstract: A superconducting element is disclosed which includes a substrate and a superconducting layer provided on the substrate and formed of an oxide having the following chemical formula:RBa.sub.2 (Cu.sub.1-x M.sub.x).sub.3 O.sub.7wherein R represents at least one element selected from the group consisting of Y, La, Nd, Pm, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, M represents at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn and Ga, and x represents a number of less than 1 but greater than 0.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: February 17, 1998
    Assignees: International Superconductivity Technology Center, Matsushita Electric Industrial Co., Ltd., Sanyo Electric Co., Ltd.
    Inventors: Akihiro Odagawa, Youichi Enomoto, Shuuichi Yoshikawa