Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
  • Patent number: 8208230
    Abstract: We disclose a magnetic read head, and method for making it, that operates in a binary rather than an analog mode. This greatly boosts signal amplitude for high area density recording as device dimensions get smaller. The device is well suited to the inclusion of side shields which further reduces side reading errors. The device has a utilization efficiency close to 100%.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: June 26, 2012
    Assignee: Headway Technologies, Inc.
    Inventor: Yue Liu
  • Patent number: 8203809
    Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.
    Type: Grant
    Filed: September 24, 2010
    Date of Patent: June 19, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Kenichi Takano, Kunliang Zhang
  • Patent number: 8203808
    Abstract: In an MR element constituted in such a manner that a pinned layer whose magnetization direction is fixed, a nonmagnetic spacer layer, and a free layer whose magnetization direction is changed according to an external magnetic field, are laminated in this order; the free layer has a multilayer constitution including a magnetic body mixed with an element having 4f electrons at a certain ratio. Specifically, the first layer in contact with the spacer layer, the third layer, the fifth layer, and the seventh layer of the free layer are formed by mixing Nd, Sm, Gd, or Tb into CoFe. The second layer and the sixth layer of the free layer are formed by mixing Nd, Sm, Gd, or Tb into NiFe. The third layer of the free layer is Cu. A damping constant of the free layer is greater than 0.018.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: June 19, 2012
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya
  • Publication number: 20120147504
    Abstract: A CPP MR read head and its method of fabrication includes a patterned CPP MR sensor stack having a SAF free layer structure that is longitudinally biased by the combination of an exchange biasing layer formed over the sensor stack and hard biasing layers that are formed adjacent to the patterned sides of the stack. The combination provides the stack with high resolution reading capabilities without the necessity for a narrow read gap formed by closely spaced top and bottom shields. Sixteen embodiments are described that provide different versions of the exchange biasing layer, different positions of the hard biasing layers and different patternings of the CPP MR sensor stack.
    Type: Application
    Filed: December 13, 2010
    Publication date: June 14, 2012
    Inventors: Yuchen Zhou, Wenyu Chen, Joe Smyth
  • Patent number: 8197953
    Abstract: A magnetic stack having a free layer having a switchable magnetization orientation, a reference layer having a pinned magnetization orientation, and a barrier layer therebetween. The stack includes an annular antiferromagnetic pinning layer electrically isolated from the free layer and in physical contact with the reference layer. In some embodiments, the reference layer is larger than the free layer.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: June 12, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Antoine Khoueir, Brian Lee, Pat Ryan, Michael Tang, Insik Jin, Paul E. Anderson
  • Patent number: 8194364
    Abstract: In an MR element of the present invention, an effect of an extremely-high MR ratio is obtained since a crystal structure of a CoFe magnetic layer in the vicinity of an interface with a spacer layer is formed as a close packed structure, such as an hcp structure and an fcc structure, and a total existing ratio of these crystal structures is 25% or more by an area ratio.
    Type: Grant
    Filed: August 31, 2009
    Date of Patent: June 5, 2012
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
  • Patent number: 8194363
    Abstract: A thin film magnetic head includes a first through fourth free layers, a spacer layer, and a bias magnetic field application layer. The first and second free layers are magnetized in opposite directions of each other in the orthogonal direction to the ABS when the bias magnetic field is applied to the first and second free layers, and are exchange-coupled such that an angle between the magnetization direction of the bias magnetic field and the first free layer is acute and such that an angle between the magnetization direction of the bias magnetic field and the second free layer is acute. Similarly, the third and fourth layers have the same configuration.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: June 5, 2012
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Yoshihiro Tsuchiya
  • Patent number: 8194365
    Abstract: A method and system for providing a magnetic structure in magnetic transducer is described. The magnetic structure includes a pinned layer, a nonmagnetic spacer layer, and a free layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer includes a first magnetic layer, a second magnetic layer, and a magnetic insertion layer between the first magnetic layer and the second magnetic layer. The first magnetic layer has a first magnetostriction. The second magnetic layer has a second magnetostriction opposite to the first magnetostriction. The magnetic insertion layer provides a growth texture barrier between the first magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: June 5, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Qunwen Leng, Chando Park, Yimin Guo, Christian Kaiser, Mahendra Pakala, Sining Mao
  • Patent number: 8191235
    Abstract: The method of the present invention provides a magnetoresistance effect element, which is capable of having a high MR ratio, corresponding to high density recording and being suitably applied to a magnetoresistance device even though a barrier layer is thinned to reduce resistance of the magnetoresistance effect element. The method of producing the magnetoresistance effect element, which includes the barrier layer composed of an oxidized metal, a first magnetic layer contacting one of surfaces of the barrier layer and a second magnetic layer contacting the other surface thereof, comprises the steps of: laminating the barrier layer on the first magnetic layer with using a target composed of the oxidized metal; and laminating the second magnetic layer on the barrier layer. The barrier layer is annealed before laminating the second magnetic layer thereon.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: June 5, 2012
    Assignees: Fujitsu Limited, Tohoku University
    Inventors: Migaku Takahashi, Masakiyo Tsunoda, Koujiro Komagaki, Yuji Uehara, Kazuyuki Sunaga
  • Patent number: 8189303
    Abstract: A thin film magnetic head includes a magneto-resistance (MR) laminated body, a lower shield layer and an upper shield layer that face the first MR magnetic layer. The lower and upper shield layers respectively have first and second anti-parallel layers and first and second antiferromagnetic layers. An exchange coupling intensity relating to an antiferromagnetic coupling between the second anti-parallel layer and the second antiferromagnetic layer is greater in the peripheral area of a projection area than that of the projection area of the upper shield layer side end surface of the MR laminated body to the film surface's orthogonal direction.
    Type: Grant
    Filed: August 12, 2008
    Date of Patent: May 29, 2012
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Yoshihiro Tsuchiya, Tsutomu Chou, Daisuke Miyauchi, Takahiko Machita
  • Patent number: 8189304
    Abstract: A magnetoresistive magnetic head according to one embodiment uses a current-perpendicular-to-plane magnetoresistive element having a laminate of a free layer, an intermediate layer, and a pinned layer, the pinned layer being substantially fixed to a magnetic field to be detected, wherein either the pinned layer or the free layer includes a Heusler alloy layer represented by a composition of X—Y—Z, wherein X is between about 45 at. % and about 55 at. % and is Co or Fe, Y accounts for between about 20 at. % and about 30 at. % and is one or more elements selected from V, Cr, Mn, and Fe, and Z is between about 20 at. % and about 35 at.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: May 29, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Susumu Okamura, Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Keizo Kato
  • Patent number: 8188558
    Abstract: In order to increase an efficiency of spin transfer and thereby reduce the required switching current, a current perpendicular to plane (CPP) magnetic element for a memory device includes either one or both of a free magnetic layer, which has an electronically reflective surface, and a permanent magnet layer, which has perpendicular anisotropy to bias the free magnetic layer.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: May 29, 2012
    Assignee: Seagate Technology LLC
    Inventors: Dexin Wang, Dimitar V. Dimitrov, Song S. Xue, Insik Jin
  • Patent number: 8184410
    Abstract: An example magnetoresistive element includes a first magnetic layer whose magnetization direction is substantially pinned toward one direction; a second magnetic layer whose magnetization direction is changed in response to an external magnetic field; and a spacer layer provided between the first magnetic layer and the second magnetic layer. At least one of the first magnetic layer and the second magnetic layer has a magnetic compound that is expressed by M1aM2bXc(where 5?a?68, 10?b?73, and 22?c?85). M1 is at least one element selected from the group consisting of Co, Fe, and Ni. M2 is at least one element selected from the group consisting of Ti, V, Cr, and Mn. X is at least one element selected from the group consisting of N, O, and C.
    Type: Grant
    Filed: September 24, 2007
    Date of Patent: May 22, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 8184408
    Abstract: A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer formed of an oxygen- or nitrogen-containing material and arranged in the magnetization pinned layer, or in the magnetization free layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: May 22, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shuichi Murakami, Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji
  • 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: 8176622
    Abstract: A process for manufacturing a high performance MTJ it is described: A first cap layer of NiFeHf is deposited on the free layer, followed by a second cap layer of Ru on Ta. The device is then heated so that oxygen trapped in the free layer diffuses into the NiFeHf layer, thereby sharpening the interface between the tunnel barrier layer and the free layer.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: May 15, 2012
    Assignee: MagIC Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong, Chyu-Jiuh Torng, Witold Kula
  • Patent number: 8174799
    Abstract: Embodiments of the present invention help to provide a single element type differential magnetoresistive magnetic head capable of achieving high resolution and high manufacturing stability. According to one embodiment, a magnetoresistive layered film is formed by stacking an underlayer film, an antiferromagnetic film, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a long distance antiparallel coupling layered film, and a differential soft magnetic free layer. The long distance antiparallel coupling layered film exchange-couples the soft magnetic free layer and the differential soft magnetic free layer in an antiparallel state with a distance of about 3 nanometers through 20 nanometers. By manufacturing the single element type differential magnetoresistive magnetic head using the magnetoresistive layered film, it becomes possible to achieve the high resolution and the high manufacturing stability without spoiling the GMR effect.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: May 8, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Katsumi Hoshino, You Sato, Hiroyuki Katada, Kazuhiro Nakamoto
  • Patent number: 8169753
    Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8166633
    Abstract: A method for manufacturing an extraordinary magnetoresistive sensor (EMR sensor) having reduced size and increased resolution is described. The sensor includes a plurality of electrically conductive leads contacting a magnetically active layer and also includes an electrically conductive shunt structure. The electrically conductive leads of the sensor and the shunt structure can be formed in a common photolithographic masking and etching process so that they are self aligned with one another. This avoids the need to align multiple photolithographic processing steps, thereby allowing greatly increased resolution and reduced lead spacing. The EMR sensor can be formed with a magnetically active layer that can be close to or at the air bearing surface (ABS) for improved magnetic spacing with an adjacent magnetic medium of a data recording system.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas Dudley Boone, Jr., Liesl Folks, Bruce Alvin Gurney, Jordan Asher Katine, Ernesto E. Marinero, Neil Smith
  • Patent number: 8164863
    Abstract: The invention provides a current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with multiple ferromagnetic sense layers. In one embodiment of the invention, a CPP TMR read sensor comprises a first sense layer formed by a ferromagnetic polycrystalline Co—Fe film, a second sense layer formed by a ferromagnetic interstitial-type amorphous Co—Fe—B film, a third sense layer formed by a ferromagnetic substitute-type amorphous Co—Fe—X film where X is Hf, Zr or Y, and a fourth sense layer formed by a ferromagnetic Ni—Fe film. The third sense layer acts as a diffusion barrier layer to suppress Ni diffusion, thus allowing the incorporation of the Ni—Fe fourth sense layer for improving ferromagnetic properties of the multiple sense layers. The multiple sense layers induce spin-dependent scattering, thus facilitating the CPP TMR read sensor to exhibit a strong TMR effect.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: April 24, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8151442
    Abstract: Magnetoresistive (MR) elements having flux guides defined by the free layer. The MR element includes a free layer, a spacer/barrier layer, a pinned layer, and a pinning layer. A back edge of the free layer (opposite the sensing surface of the MR element) extends past a back edge of the spacer/barrier layer. The portion of the free layer extending past the back edge of the spacer/barrier layer defines a continuous flux guide. The flux guide is processed to reduce the conductive characteristics of the flux guide, thereby reducing current shunt loss in the flux guide.
    Type: Grant
    Filed: March 31, 2010
    Date of Patent: April 10, 2012
    Assignee: Hitachi Global Strorage Technologies Netherlands, B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 8154828
    Abstract: An MR element in a CPP structure includes a spacer layer made of Cu, a magnetic pinned layer containing CoFe and a free layer containing CoFe that are laminated to sandwich the spacer layer. The free layer is located below the magnetic pinned layer. The free layer is oriented in a (001) crystal plane, the spacer layer is formed and oriented in a (001) crystal plane on the (001) crystal plane of the free layer. Therefore, in a low resistance area where an area resistivity (AR) of the MR element is, for example, lower than 0.3 ?·?m2, an MR element that has a large variation of a resistance is obtained.
    Type: Grant
    Filed: July 10, 2009
    Date of Patent: April 10, 2012
    Assignee: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Shinji Hara, Kiyoshi Noguchi, Migaku Takahashi, Masakiyo Tsunoda
  • Patent number: 8154825
    Abstract: It is made possible to provide a magnetic head that can stabilize the high-frequency magnetic field generated from the spin torque oscillator. A magnetic head includes: first and second main magnetic poles; and a spin torque oscillator provided between the first and second main magnetic poles.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: April 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Takashita, Hitoshi Iwasaki, Kenichiro Yamada, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Mariko Shimizu
  • Patent number: 8149547
    Abstract: An MR element includes a pinned layer, a free layer and a nonmagnetic space layer or a tunnel barrier layer sandwiched between the pinned layer and the free layer. A magnetization direction of the free layer is substantially perpendicular to a film surface thereof, and a magnetization direction of the pinned layer is substantially parallel to a film surface thereof.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: April 3, 2012
    Assignee: TDK Corporation
    Inventors: Naoki Ohta, Satoshi Miura, Tomohito Mizuno
  • Patent number: 8147994
    Abstract: A layered structure includes an amorphous Ta layer, a metallic oxide layer formed from zinc oxide (ZnO) or magnesium oxide (MgO) on the Ta layer, and a FePt magnetic layer formed on the metallic oxide layer. Therefore, an L10 structural FePt ordered alloy is obtained at a temperature of 300° C. or lower.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: April 3, 2012
    Assignee: TDK Corporation
    Inventors: Hironobu Matsuzawa, Tsutomu Chou
  • Patent number: 8149548
    Abstract: Embodiments of the present invention provide a magnetic head having a read head of stable reading operation and with less magnetic fluctuation noise. According to one embodiment, a free layer has a structure comprising two ferromagnetic layers (a first free layer and a second free layer) that are coupled anti-ferromagnetically by way of a non-magnetic intermediate layer, in which the magnetization amount of the first free layer is set to larger than the magnetization amount of the second free layer. Further, the magnetic domains in the first free layer and the second free layer are stabilized simultaneously by increasing the distance between the second free layer and the magnetic domain control film to be more than the distance between the first free layer and the magnetic domain control film, thereby adjusting the magnetization amount of the magnetic domain control film.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: April 3, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands BV
    Inventors: Masahiko Hatatani, Katsuro Watanabe, Nubuo Yoshida, Katsumi Hoshino
  • Patent number: 8144437
    Abstract: An orthogonalizing bias function part formed at a rear part of an MR part in a DFL structure influencing a substantial orthogonalizing function of first and second ferromagnetic layers in respective magnetization directions thereof, non-magnetic metal layers formed to abut both ends of the MR part in a width direction and separated from both ends of the MR part by respective insulation layers, each of the non-magnetic metal layers being in a two-layer structure configured with a first non-magnetic metal layer positioned at a lower side as a lower layer and a second non-metal layer positioned at an upper side as an upper layer are configured, and relationship R2<R1 is met, where R1 is a milling rate for the first non-magnetic metal layer that is the lower layer, and R2 is another milling rate for the second non-magnetic metal layer that is the upper layer.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: March 27, 2012
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Keita Kawamori, Takahiko Machita, Tetsuya Roppongi
  • Patent number: 8139324
    Abstract: To provide a magnetic head that is suited for high recording density magnetic read and write, and has little noise. A magnetic pinned layer is formed on a non-magnetic electrode layer via a first insulating layer, and a magnetic free layer is formed on a medium-side plane of the non-magnetic electrode layer via a second insulating layer. A circuit for flowing current between the non-magnetic electrode layer and the magnetic pinned layer via the first insulating layer, and a circuit for measuring voltage between the non-magnetic electrode layer and the magnetic free layer are connected to the magnetic free layer. The medium-side plane on which the magnetic free layer is formed may be a plane substantially parallel to the surface of the medium, or may be a plane tilted from the surface of the medium.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: March 20, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Takahashi, Masaki Yamada
  • Patent number: 8136227
    Abstract: A magnetic head having non-GMR shunt for perpendicular recording and method for making magnetic head having non-GMR shunt for perpendicular recording is disclosed. A shunt is provided for shunting charge from a read sensor. The shunt is formed co-planar with the read sensor and is fabricated using non-GMR materials.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: March 20, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Michael Feldbaum, Quang Le, Edward H. Lee, Neil L. Robertson, Charles G. Seegel, III
  • Patent number: 8130475
    Abstract: The present invention relates to a method of manufacturing a DFL type thin film magnetic head. The method includes laminating each of the layers from the lower magnetization control layer to the upper exchange coupling layer above the substrate; laminating an auxiliary magnetization control layer including at least a CoZrTa layer above the upper exchange coupling layer; forming at least each of the layers from the lower exchange coupling layer to the auxiliary magnetization control layer in pillar shape, and disposing the bias magnetic field application layer at an opposite position with respect to the ABS of each of the pillar shaped layers; trimming the auxiliary magnetization control layer by removing a part of the auxiliary magnetization control layer that is formed in the pillar shape, and disposing the upper shield layer such that the trimmed auxiliary magnetization control layer is at least covered.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: March 6, 2012
    Assignee: TDK Corporation
    Inventors: Keita Kawamori, Yoshihiro Tsuchiya, Daisuke Miyauchi, Takahiko Machita
  • Patent number: 8130474
    Abstract: A TMR sensor structure having free and reference layers, where the magnetic orientations of the free and reference layers are non-orthogonal. In one embodiment, a ferromagnetic free layer film has a bias-point magnetization nominally oriented in plane of the film thereof, in a first direction at an angle ?fb with respect to a longitudinal axis being defined as the intersection of the plane of deposition of the free layer and the plane of the ABS. A ferromagnetic reference layer film has a bias-point magnetization nominally oriented in a plane of the film thereof, in a second direction at angle ?rb with respect to said longitudinal axis that is not orthogonal to the said first direction.
    Type: Grant
    Filed: July 14, 2008
    Date of Patent: March 6, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jeffrey Robinson Childress, Neil Smith
  • Patent number: 8105703
    Abstract: The conventional free layer in a CPP GMR or TMR read head has been replaced by a tri-layer laminate comprising Co rich CoFe, moderately Fe rich NiFe, and heavily Fe rich NiFe. The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is described.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: January 31, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Hui-Chuan Wang, Min Li, Tong Zhao, Kunliang Zhang, Chyu-Jiuh Torng
  • Patent number: 8107201
    Abstract: A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: January 31, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Yun-Fei Li, Chyu-Jiuh Torng, Chen-Jung Chien
  • Patent number: 8098464
    Abstract: A magnetic field detecting element includes: first and second free layers; a spacer layer; a first exchange coupling transmitting layer; a first pinned layer; a second exchange coupling transmitting layer; and a second pinned layer. The first and second pinned layers are magnetized in directions which are perpendicular to an air bearing surface and which are anti-parallel with each other, respectively. The first exchange coupling transmitting layer or second exchange coupling transmitting layer has a positive exchange coupling strength, while the other has a negative exchange coupling strength. The first or second pinned layer that is located adjacent to the first or second exchange coupling transmitting layer having the negative exchange coupling strength has a larger magnetic film thickness than the first or second free layer that is located adjacent to the first or second exchange coupling transmitting layer having the negative exchange coupling strength.
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: January 17, 2012
    Assignee: TDK Corporation
    Inventor: Koji Shimazawa
  • Patent number: 8094420
    Abstract: The invention provides a magnetoresistive device of the CCP (current perpendicular to plane) structure comprising a magnetoresistive unit sandwiched between soft magnetic shield layers with a current applied in the stacking direction. The magnetoresistive unit comprises a nonmagnetic intermediate layer sandwiched between ferromagnetic layers. A planar framework positions the soft magnetic shield layers and comprises a combination of a nonmagnetic gap layer with a bias magnetic field-applying layer constructed by repeating the stacking of a multilayer unit comprising a nonmagnetic underlay layer and a high coercive material layer. The nonmagnetic gap layer is designed and located such that a magnetic flux given out of the bias magnetic field-applying layer is efficiently directed along a closed magnetic path around the framework to form a single domain of magnetization.
    Type: Grant
    Filed: May 23, 2008
    Date of Patent: January 10, 2012
    Assignee: TDK Corporation
    Inventors: Toshiyuki Ayukawa, Takahiko Machita, Daisuke Miyauchi, Tsutomu Chou, Koji Shimazawa, Shinji Hara, Tomohito Mizuno, Yoshihiro Tsuchiya
  • Patent number: 8085512
    Abstract: A magnetic field detecting element comprises: a stack which includes first, second and third magnetic layers whose magnetization directions depend upon an external magnetic field, the second magnetic layer being positioned between the first magnetic layer and the third magnetic layer, a first non-magnetic intermediate layer sandwiched between the first magnetic layer and the second magnetic layer, and a second non-magnetic intermediate layer sandwiched between the second magnetic layer and the third magnetic layer, wherein the stack is adapted such that sense current flows in a direction that is perpendicular to a film surface thereof; and a bias magnetic layer which is provided on a side of the stack, the side being opposite to an air bearing surface of the stack.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: December 27, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Shinji Hara, Koji Shimazawa, Tsutomu Chou
  • Patent number: 8081404
    Abstract: A magnetoresistive element includes: a free layer made of a ferromagnetic material, the free layer configured to change the direction of magnetization under the influence of an external magnetic field; an insulating layer overlaid on the free layer, the insulating layer made of an insulating material; an amorphous reference layer overlaid on the insulating layer, the amorphous reference layer made of a ferromagnetic material, the amorphous reference layer configured to fix the magnetization in a predetermined direction; a crystal layer overlaid on the amorphous reference layer, the crystal layer containing crystal grains; a non-magnetic layer overlaid on the crystal layer, the non-magnetic layer containing crystal grains having grown from the crystal grains in the crystal layer; and a pinned layer overlaid on the non-magnetic layer, the pinned layer configured to fix the magnetization in a predetermined direction.
    Type: Grant
    Filed: August 27, 2009
    Date of Patent: December 20, 2011
    Assignee: Fujitsu Limited
    Inventors: Takahiro Ibusuki, Shinjiro Umehara, Masashige Sato
  • Patent number: 8081403
    Abstract: A magnetic element includes a pinned layer, a nonferromagnetic spacer layer, and a free layer. The nonferromagnetic spacer layer resides between the pinned layer and the free layer. The free layer has a track width of not more than 0.08 micron.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: December 20, 2011
    Assignee: Western Digital (Fremont), LLC
    Inventors: Benjamin Chen, Hongping Yuan, Danning Yang, Wei Zhang, Hugh C. Hiner, Lei Wang, Yingjian Chen, Brant Nease
  • Patent number: 8077436
    Abstract: A magnetoresistance effect element comprises: a magnetoresistive stack including: first, second and third magnetic layers whose magnetization directions change in accordance with an external magnetic field, said second magnetic layer being located between said first magnetic layer and the third magnetic layer; a first non-magnetic intermediate layer sandwiched between said first and second magnetic layers; and a second non-magnetic intermediate layer sandwiched between said second and third magnetic layers; wherein sense current is adapted to flow in a direction perpendicular to a film plane; a bias magnetic layer provided on an opposite side of said magnetoresistive stack from an air bearing surface.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Satoshi Miura, Tomohito Mizuno, Takeo Kagami
  • Patent number: 8072800
    Abstract: Techniques and magnetic devices associated with a magnetic element that includes a fixed layer having a fixed layer magnetization and perpendicular anisotropy, a nonmagnetic spacer layer, and a free layer having a changeable free layer magnetization and perpendicular anisotropy.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: December 6, 2011
    Assignee: Grandis Inc.
    Inventors: Eugene Youjun Chen, Shengyuan Wang
  • Patent number: 8072712
    Abstract: At both sides of an element portion, a first hard bias layer having a higher residual magnetization Mr and a second hard bias layer having a higher coercive force Hc are deposited in that order from the bottom with one end of the first hard bias layer being closed close to a free magnetic layer. A film thickness ratio of the first hard bias layer in a whole hard bias layer is from 35% to 75%. This stabilizes magnetization in the free magnetic layer to reduce asymmetry, thus enabling improvement in stability of reproducing characteristics including noise suppression.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: December 6, 2011
    Assignee: TDK Corporation
    Inventors: Masahlko Ishizone, Yasuo Hayakawa
  • Patent number: 8072714
    Abstract: A barrier layer is disposed over a pinned layer made of ferromagnetic material having a fixed magnetization direction, the barrier layer having a thickness allowing electrons to transmit therethrough by a tunneling phenomenon. A first free layer is disposed over the barrier layer, the first free layer being made of amorphous or fine crystalline soft magnetic material which changes a magnetization direction under an external magnetic field. A second free layer is disposed over the first free layer, the second free layer being made of crystalline soft magnetic material which changes a magnetization direction under an external magnetic field and being exchange-coupled to the first free layer. A tunneling magnetoresistance device is provided which has good magnetic characteristics and can suppress a tunnel resistance change rate from being lowered.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: December 6, 2011
    Assignee: Fujitsu Limited
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Patent number: 8059374
    Abstract: A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low ? in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) ? and (?) ? values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, ?˜1×10?6, and RA=1.2 ohm-um2 when FL1 is CoFe/CoFeB/CoFe, FL2 is CoFe/NiFe/CoFe, and the insertion layer is CoTa or CoFeBTa.
    Type: Grant
    Filed: January 14, 2009
    Date of Patent: November 15, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Min Li, Kunliang Zhang
  • Patent number: 8054587
    Abstract: An MR element includes a lower shield layer, a magnetization free function part stacked on the lower shield layer, an upper shield layer stacked on the magnetization free function part, a nonmagnetic intermediate layer stacked on a surface, that is opposite to a magnetically sensitive surface, of the magnetization free function part, and a magnetization fixed function part stacked on the nonmagnetic intermediate layer. The nonmagnetic intermediate layer and the magnetization fixed function part are formed only within an outer region of the magnetization free function part, located opposite side to the magnetically sensitive surface.
    Type: Grant
    Filed: January 9, 2009
    Date of Patent: November 8, 2011
    Assignee: TDK Corporation
    Inventor: Takumi Yanagisawa
  • Patent number: 8049997
    Abstract: A first shield portion located below an MR stack includes a first main shield layer, a first antiferromagnetic layer, and a first magnetization controlling layer including a first ferromagnetic layer exchange-coupled to the first antiferromagnetic layer. A second shield portion located on the MR stack includes a second main shield layer, a second antiferromagnetic layer, and a second magnetization controlling layer including a second ferromagnetic layer exchange-coupled to the second antiferromagnetic layer. The MR stack includes two free layers magnetically coupled to the two magnetization controlling layers. Only one of the two magnetization controlling layers includes a third ferromagnetic layer that is antiferromagnetically exchange-coupled to the first or second ferromagnetic layer through a nonmagnetic middle layer. The first shield portion includes an underlayer disposed on the first main shield layer, and the first antiferromagnetic layer is disposed on the underlayer.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: November 1, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Takahiko Machita, Koji Shimazawa
  • Patent number: 8043732
    Abstract: Magnetic tunnel junction cells and methods of making magnetic tunnel junction cells that include a radially protective layer extending proximate at least the ferromagnetic free layer of the cell. The radially protective layer can be specifically chosen in thickness, deposition method, material composition, and/or extent along the cell layers to enhance the effective magnetic properties of the free layer, including the effective coercivity, effective magnetic anisotropy, effective dispersion in magnetic moment, or effective spin polarization.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: October 25, 2011
    Assignee: Seagate Technology LLC
    Inventors: Paul E. Anderson, Song S. Xue
  • Patent number: 8045300
    Abstract: A free magnetic layer has a laminated structure in which a first magnetic sublayer composed of Co—Fe or Fe and a second magnetic sublayer composed of Co—Fe—B or Fe—B are formed, in that order, on an insulating barrier layer composed of Mg—O. This effectively improves the rate of change in resistance (?R/R) compared with the related art.
    Type: Grant
    Filed: February 25, 2008
    Date of Patent: October 25, 2011
    Assignee: TDK Corporation
    Inventors: Kazumasa Nishimura, Yosuke Ide, Naoya Hasegawa, Masamichi Saito, Yoshihiro Nishiyama, Ryo Nakabayashi, Hidekazu Kobayashi
  • Patent number: 8036024
    Abstract: In a ferromagnetic tunnel junction element, a recording layer is in a circular shape, which can suppress an increase in magnetization switching field due to miniaturization of the element. Further, the recording layer includes a first ferromagnetic layer, a first non-magnetic layer, a second ferromagnetic layer, a second non-magnetic layer, and a third ferromagnetic layer successively stacked. The first and second ferromagnetic layers, and the second and third ferromagnetic layers are coupled antiparallel to each other, so that it is possible to control the magnetization distribution of the recording layer in an approximately single direction.
    Type: Grant
    Filed: May 30, 2006
    Date of Patent: October 11, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Kobayashi, Sadeh Beysen
  • Patent number: 8035931
    Abstract: The conventional free layer in a TMR read head has been replaced by a composite of two or more magnetic layers, one of which is iron rich The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: October 11, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Chyu-Jiuh Torng
  • Patent number: 8031441
    Abstract: A CPP-GMR spin valve having a composite spacer layer comprised of at least one metal (M) layer and at least one semiconductor or semi-metal (S) layer is disclosed. The composite spacer may have a M/S, S/M, M/S/M, S/M/S, M/S/M/S/M, or a multilayer (M/S/M)n configuration where n is an integer ?1. The pinned layer preferably has an AP2/coupling/AP1 configuration wherein the AP2 portion is a FCC trilayer represented by CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where y is 0 to 60 atomic %, and z is 75 to 100 atomic %. In one embodiment, M is Cu with a thickness from 0.5 to 50 Angstroms and S is ZnO with a thickness of 1 to 50 Angstroms. The S layer may be doped with one or more elements. The dR/R ratio of the spin valve is increased to 10% or greater while maintaining acceptable EM and RA performance.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: October 4, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Moris Dovek, Yue Liu