Using Exchange Couple Biasing Patents (Class 360/327.32)
  • Patent number: 10490396
    Abstract: A magnet assembly for an ion source comprising a first magnet of a first magnet type; a second magnet of a second magnet type; a heat shield located between the first magnet and the second magnet; and a heat sink coupled to the heat shield; wherein the first magnet type having a higher Curie temperature than the second magnet type.
    Type: Grant
    Filed: March 27, 2018
    Date of Patent: November 26, 2019
    Assignee: Thermo Finnigan LLC
    Inventors: Edward B. McCauley, Deven L. Shinholt
  • Patent number: 10060880
    Abstract: Magnetoresistive (MR) sensors employing dual MR devices for differential MR sensing are provided. These MR sensors may be used as biosensors to detect the presence of biological materials as an example. An MR sensor includes dual MR sensor devices that may be tunnel magnetoresistive (TMR) devices or giant magnetoresistive (GMR) devices as examples. The MR devices are arranged such that a channel is formed between the MR devices for receiving magnetic nanoparticles. A magnetic stray field generated by the magnetic nanoparticles causes free layers in the MR devices to rotate in opposite directions, thus causing differential resistances between the MR devices for greater sensing sensitivity. Further, as another aspect, by providing the channel between the MR devices, the magnetic stray field generated by the magnetic nanoparticles can more easily rotate the magnetic moment orientation of the free layers in the MR devices, thus further increasing sensitivity.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: August 28, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Wei-Chuan Chen, Jung Pill Kim, Seung Hyuk Kang
  • Patent number: 9689902
    Abstract: When miniaturizing an ammeter or wattmeter, a magnetoresistance effect element given a barber-pole electrode could be considered an efficient device. It was considered that a barber-pole electrode formed at 45° with respect to an axis of easy magnetization (the longitudinal direction of a rectangular-shaped element) would be the most efficient. Current is refracted, however, when the current passes through the boundaries of substances with different conductivity, so a barber-pole electrode formed at 45° is not the most efficient. According to the invention, it is possible to provide a highly efficient magnetoresistance element having a rectangular magnetic film whereupon an axis of easy magnification is induced in the longitudinal direction, and a barber-pole electrode which is formed upon the magnetic film at an oblique angle ? to the longitudinal direction, where the magnetoresistance element takes into account current refraction at the boundary between the electrode and the magnetic film.
    Type: Grant
    Filed: November 21, 2013
    Date of Patent: June 27, 2017
    Assignee: SIRC CO., LTD
    Inventor: Hiroaki Tsujimoto
  • Patent number: 8182705
    Abstract: A method for producing a thin film magnetic head including a magnetoresistive effect element (MR element) that has a magnetic sensor multi-layered film with a polygonal shape such that a vertex angle faces an air bearing surface (ABS) and a tip of the vertex angle is cut when the magnetic sensor multi-layered film is viewed from an X-Y plane that is parallel to a plane of a lower shield electrode layer includes a step for stopping a lapping process by using a measurement point in which a resistance value is steeply increased while the lapping face is gradually approaching the vertex angle of polygonal shape by lapping from the ABS side. Therefore, an excellent effect in which an ultra narrow track width that exceeds limits of photolithography technology can be securely and constantly formed is obtained.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: May 22, 2012
    Assignee: TDK Corporation
    Inventors: Kosuke Tanaka, Daisuke Miyauchi, Takumi Yanagisawa
  • Patent number: 7007374
    Abstract: A narrow track width read sensor having a high magnetoresistive sensitivity is made using a self-aligned process which requires the use of only a single resist mask. A plurality of sensor layers is deposited over a substrate. After forming a resist mask in the central region, first lead layers are deposited in the end regions and over the resist mask. Using the resist mask, ion milling is performed such that the first lead layers and sensor layers in the end regions are substantially removed but sensor layers in the central region remain, to thereby form a read sensor having lead overlays on the edges thereof. Hard bias and second lead layers are then deposited in the end regions and over the resist mask. After the resist mask is removed, the top of the read sensor may be oxidized through an exposure to oxygen plasma.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: March 7, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Jeffrey Scott Lille
  • Patent number: 6741433
    Abstract: As to a magnetic tunnel junction magneto-resistive head, which comprises an antiferromagnetically coupling layer, a pinned ferromagnetic layer adjacent to said antiferromagnctically coupling layer and magnetically pinned by a magnetization of said antiferromagnctically coupling layer, a free ferromagnetic layer which is magnetically free from the magnetization of said antiferromagnetically coupling layer, insulating layers sandwiched by these ferromagnetic layers, a stacked layers of ferromagnetic layers to control the magnetic domain of said free ferromagnetic layer and a pair of electrodes to apply a current to these layers and films, said stacked layers of ferromagnetic layers are formed between said free ferromagnetic layer and one of said electrodes. According to this composition, it is possible to present a magnetic tunnel junction magneto-resistive sensor with preferable domain controlling force against the free ferromagnetic layer.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: May 25, 2004
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventor: Koichi Nishioka
  • Patent number: 6657825
    Abstract: A magnetoresistive sensor for use in a data storage device has a recessed sensing element (magnetic tunnel junction, CPP spin valve, etc.) with an exchange biased sensing ferromagnetic (free) layer, and a flux guide that magnetically connects the sensing element to a sensing surface of the sensor. The free layer is selectively exchange biased by a layer of exchange bias material placed under non-active regions of the free layer that lie outside the sensing element and flux guide track widths. The flux guide is provided by extending the free layer from a forward edge of the sensing element to the sensor surface. Advantageously, the sensing element and the flux guide have equal track width so that magnetic flux directed from the flux guide into the sensing element is not diluted with consequent loss of sensitivity.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: December 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: Kuok San Ho, Tao Pan
  • Patent number: 6574080
    Abstract: A magnetoresistive thin film head comprises a magnetoresistive element including an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer, and a pair of the right and the left laminated transverse biasing layers, each including a nonmagnetic layer, a ferromagnetic layer and an antiferromagnetic layer, provided on the free magnetic layer constituting said magnetoresistive element. The layer thickness of said nonmagnetic layer has been established to a certain specific value so that magnetizing direction in said free magnetic layer opposing to the ferromagnetic layer via said nonmagnetic layer assumes a direction that is opposite to that of said ferromagnetic layer.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: June 3, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaya Sakaguci, Toshio Fukazawa
  • Publication number: 20030063415
    Abstract: A seed layer is formed of a Cr film with a thickness of 15 Å or more and 50 Å or less comprising at least partially an amorphous phase, thereby enabling wettability of the surface the seed layer to be remarkably improved as compared with conventional one, the unidirectional bias magnetic field in the pinned magnetic layer to be increased, and the surface of each layer on the seed layer to have good lubricity.
    Type: Application
    Filed: July 17, 2002
    Publication date: April 3, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Kenichi Tanaka
  • Patent number: 6449131
    Abstract: A dual stripe magnetoresistive (DSMR) sensor element, and a method for fabricating the dual stripe magnetoresistive (DSMR) sensor element. When fabricating the dual stripe magnetoresistive (DSMR) sensor element while employing the method, there are employed two pair of patterned magnetic biasing layers formed of a single magnetic biasing material. The two pair of patterned magnetic biasing layers bias a pair of patterned magnetoresistive (MR) layers in a pair of opposite canted directions.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: September 10, 2002
    Assignee: Headway Technologies, Inc.
    Inventors: Yimin Guo, Kochan Ju, Po-Kang Wang, Cherng-Chyi Han, Hui-Chuan Wang
  • Publication number: 20020114113
    Abstract: A magnetoresistive (MR) read sensor fabricated on a substrate includes a ferromagnetic layer that is exchange coupled with an antiferromagnetic layer made of a defined composition of iridium manganese. A tantalum layer is used so that the exchange field and coercivity do not change with variations in annealing temperature. The antiferromagnetic layer is formed with a material composition of IrxMn100-x wherein x is in the range of 15<x>23. In an embodiment of a spin valve structure, the tantalum layer is disposed over the substrate and the antiferromagnetic layer is in direct contact with a pinned ferromagnetic layer. In another embodiment, the IrMn layer is formed over a soft active layer. In a third embodiment using exchange pinning, spaced IrMn regions are formed over the active MR layer to define the sensor track width.
    Type: Application
    Filed: March 28, 2002
    Publication date: August 22, 2002
    Inventors: Marcos M. Lederman, Daniel A. Nepela, Hua-Ching Tong
  • Patent number: 6430015
    Abstract: A longitudinally magnetically biased dual stripe magnetoresistive (DSMR) sensor element comprises a first patterned magnetoresistive (MR) layer. There are contacts at the opposite ends of the patterned magnetoresistive (MR) layer with a first pair of stacks defining a track width of the first magnetoresistive (MR) layer with a first pair of stacks defining a track width of the first magnetoresistive (MR) layer, each of the stacks including a first Anti-Ferro-Magnetic (AFM) layer and a first lead layer. With the first MR layer in place the device was annealed in the presence of a longitudinal external magnetic field. A second patterned magnetoresistive (MR) layer was formed above the previous structure. There are contacts at the opposite ends of the second patterned magnetoresistive (MR) layer with a second pair of stacks defining a second track width of the second patterned magnetoresistive (MR) layer.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: August 6, 2002
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, Mao-Min Chen, Cheng T. Horng, Jei-Wei Chang
  • Publication number: 20020021537
    Abstract: A PtMn alloy film known as an antiferromagnetic material having excellent corrosion resistance is used for an antiferromagnetic layer. However, an exchange coupling magnetic field is decreased depending upon the conditions of crystal grain boundaries. Therefore, in the present invention, the crystal grain boundaries formed in an antiferromagnetic layer (PtMn alloy film) and the crystal grain boundaries formed in a ferromagnetic layer are made discontinuous in at least a portion of the interface between both layers. As a result, the antiferromagnetic layer can be appropriately transformed to an ordered lattice by heat treatment to obtain a larger exchange coupling magnetic field than a conventional element.
    Type: Application
    Filed: July 9, 2001
    Publication date: February 21, 2002
    Applicant: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito
  • Patent number: 6344955
    Abstract: A magnetoresistive element comprising a magnetic sensitive film responding to a magnetic field applied from the outside and a magnetic domain control film applying a bias magnetic field to said magnetic sensitive film in the longitudinal direction in which a sense current flows, wherein in case of assuming that the minimum magnetical thickness of said magnetic domain control film determined in consideration of the minimum magnetic field Hmin required for operation, of a longitudinal bias magnetic field applied to said magnetic sensitive film is &agr; (gauss-&mgr;m), the magnetical thickness x (gauss-&mgr;m) of the magnetic sensitive film given by the product of the remnant magnetization Br1 (gauss) of said magnetic sensitive film and its film thickness THx (&mgr;m), and the magnetical thickness y (gauss-&mgr;m) of the magnetic domain control film given by the product of the film thickness THy (&mgr;m) of said magnetic domain control film and its remnant magnetization Br2 (gauss) are set so as to meet “y
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: February 5, 2002
    Assignee: TDK Corporation
    Inventors: Jun-ichi Sato, Fumihiro Hiromatsu
  • Publication number: 20010053053
    Abstract: An exchange coupling film has an antiferromagnetic layer, a pinned magnetic layer, and a seed layer provided on the side of the antiferromagnetic layer 4 opposite to the pinned magnetic layer. The seed layer has a crystalline structure constituted mainly by face-centered cubic crystals with (111) planes substantially aligned. The seed layer is preferably non-magnetic. A laminate structure including the antiferromagnetic layer and a free layer inclusive of the intervening layers have crystalline orientations with their (111) planes substantially aligned, so that large crystal grains and, hence, large ratio of resistance variation can be achieved.
    Type: Application
    Filed: April 11, 2001
    Publication date: December 20, 2001
    Inventors: Masamichi Saito, Naoya Hasegawa, Yosuke Ide, Kenichi Tanaka
  • Patent number: 6317301
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting a magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein the resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: November 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Patent number: 6317302
    Abstract: A thin-film magnetic read head device comprises an end face extending in a first direction, in which a magnetic information carrier is movable with respect to the magnetic head device, and in a second direction, perpendicular to said first direction. The magnetic head device further comprises a multilayer structure with at least two soft-magnetic layers separated by a magnetic insulation layer and with at least one exchange biasing layer, which multilayer structure extends in the second direction and in a third direction, perpendicular to the first and the second direction, and forms at least one flux path in the first and the third direction. The exchange coupling between one of the soft-magnetic layers and the exchange biasing layer is at least partly reduced locally, i.e. interrupted or at least substantially reduced, in at least the second direction, while the exchange biasing layer extends uninterruptedly in the region of said reductions.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: November 13, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Hans W. Van Kesteren, Derk J. Adelerhof, Reinder Coehoorn
  • Patent number: 6310751
    Abstract: A dual stripe magnetoresistive (DSMR) sensor element, and a method for fabricating the dual stripe magnetoresistive (DSMR) sensor element. When fabricating the dual stripe magnetoresistive (DSMR) sensor element while employing the method, there are employed two pair of patterned longitudinal magnetic biasing layers formed of a single longitudinal magnetic biasing material longitudinally magnetically biased in substantially anti-parallel directions. When longitudinally magnetically biasing the second pair of patterned longitudinal magnetic biasing layers there is employed a thermal annealing method employing a thermal annealing temperature, a thermal annealing exposure time and an extrinsic magnetic bias field strength such that the pair of longitudinally magnetically biased patterned first longitudinal magnetic biasing layers is not substantially demagnetized.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: October 30, 2001
    Assignee: Headway Technologies, Inc.
    Inventors: Yimin Guo, Kochan Ju, Hui-Chuan Wang, Simon H. Liao
  • Publication number: 20010014001
    Abstract: A magnetoresistance effect magnetic head includes a magnetoresistance effect element having first and second ends. An electrically insulating biasing portion is at ends of the magnetoresistance effect element to apply a longitudinal bias magnetic field to the magnetoresistance effect element and to suppress leakage current at the ends of the magnetoresistance element. The biasing portion can include an intermediate longitudinal bias application layer disposed between a first insulating antiferromagnetic layer and a second layer that can be an antiferromagnetic layer. The bias portion can also be formed as one bias application layer.
    Type: Application
    Filed: April 4, 2001
    Publication date: August 16, 2001
    Applicant: FUJITSU LIMITED
    Inventors: Kenichi Aoshima, Kenji Noma, Junichi Ito
  • Patent number: 6266217
    Abstract: a magnetic head with a head face includes a multilayer structure with a flux guide, a magnetoresistive sensor, and an intermediate layer present between the flux guide and the sensor. The intermediate layer includes an anti-ferromagnetic oxide which insulates the sensor from the flux guide and also magnetically biases the sensor.
    Type: Grant
    Filed: March 1, 1999
    Date of Patent: July 24, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Jacobus J. M. Ruigrok, Pieter J. Van Der Zaag
  • Patent number: RE37819
    Abstract: The present invention provides a magnetoresistive head wherein: a magnetoresistive film is created in a read-track region at the center of the magnetoresistive head; an antiferromagnetic film and a ferromagnetic film experiencing an exchange coupling magnetic field due to direct contact with the antiferromagnetic film are created on each end of the magnetoresistive film outside the read-track region in such a way that the ferromagnetic film is located beside the magnetoresistive film; a nonmagnetic intermediate film is created between the magnetoresistive film and the ferromagnetic film for preventing ferromagnetic coupling from being developed on a contact boundary surface between the magnetoresistive film and the ferromagnetic film and for making crystal orientations of the antiferromagnetic film and the ferromagnetic film uniform; and bias magnetization is applied to the magnetoresistive film by exchange coupling between the antiferromagnetic film and the ferromagnetic film.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: August 13, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventors: Masamichi Saito, Toshinori Watanabe, Toshihiro Kuriyama
  • Patent number: RE37992
    Abstract: A magnetoresistive head including a magnetoresistive film formed in a read-track region, and antiferromagnetic and ferromagnetic films are formed on each end of the magnetoresistive film outside of the read-track region such that bias magnetization is applied to the magnetoresistive film by exchange coupling between the antiferromagnetic film and the ferromagnetic film. A nonmagnetic intermediate film is formed between the ferromagnetic film and the magnetoresistive film for preventing ferromagnetic coupling on a contact boundary surface between the ferromagnetic film and the magnetoresistive film. In accordance with another aspect, a magnetoresistive head includes an antiferromagnetic layer formed from an X—Mn alloy, where X is an element selected from the group consisting of Pt, Rh, Ru, Tr, and Pd. An interdiffusion layer is formed between the antiferromagnetic film and a ferromagnetic layer or a pinned magnetic layer by heat treatment.
    Type: Grant
    Filed: April 7, 1999
    Date of Patent: February 18, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Masamichi Saito, Toshinori Watanabe, Toshihiro Kuriyama