Patents by Inventor Kaizhong Gao

Kaizhong Gao 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: 8000128
    Abstract: A resistive random access memory (RRAM) cell that includes a first electrode having a lower portion, a continuous side portion and an upper portion, the lower portion and the continuous side portion having an outer surface and an inner surface; a resistive layer having a lower portion, a continuous side portion and an upper portion, the lower portion and the continuous side portion having an outer surface and an inner surface; and a second electrode having a lower portion, an upper portion and an outer surface; wherein the outer surface of the resistive layer directly contacts the inner surface of the first electrode.
    Type: Grant
    Filed: July 14, 2010
    Date of Patent: August 16, 2011
    Assignee: Seagate Technology LLC
    Inventors: Shaoping Li, Insik Jin, Zheng Gao, Eileen Yan, Kaizhong Gao, Haiwen Xi, Song Xue
  • Publication number: 20110194343
    Abstract: Spin-transfer torque memory having a compensation element is disclosed. A spin-transfer torque memory unit includes a free magnetic layer having a magnetic easy axis and a magnetization orientation that can change direction due to spin-torque transfer when a write current passes through the spin-transfer torque memory unit; a reference magnetic element having a magnetization orientation that is pinned in a reference direction; an electrically insulating and non-magnetic tunneling barrier layer separating the free magnetic layer from the magnetic reference element; and a compensation element adjacent to the free magnetic layer. The compensation element applies a bias field on the magnetization orientation of the free magnetic layer. The bias field is formed of a first vector component parallel to the easy axis of the free magnetic layer and a second vector component orthogonal to the easy axis of the free magnetic layer.
    Type: Application
    Filed: April 14, 2011
    Publication date: August 11, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Haiwen Xi, Wenzhong Zhu, Olle Heinonen
  • Publication number: 20110194213
    Abstract: In some examples, a system comprising a data storage member including a magnetic storage medium, the magnetic storage medium having a plurality of magnetic bit domains aligned on at least one data track, where a transition boundary between respective magnetic bit domains defines a transition curvature. The system may further comprise a magnetic read head including a first shield layer, a second shield layer, and a read sensor stack provided proximate to the first and second shield layers, where the magnetic read head senses a magnetic field of each of the plurality of magnetic bit domains according to a read playback sensitivity function. In some examples, the shield layers and read sensor stack may be configured to provide a reader playback sensitivity function that substantially corresponds to the shape of the respective magnetic bit domains.
    Type: Application
    Filed: February 8, 2010
    Publication date: August 11, 2011
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Xilin Peng, Zhongyan Wang, Yonghua Chen
  • Publication number: 20110177621
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Application
    Filed: March 28, 2011
    Publication date: July 21, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Publication number: 20110164335
    Abstract: A magnetic sensor includes a reference layer having a first magnetization direction and a free layer assembly having an effective magnetization direction substantially perpendicular to the first magnetization direction and substantially perpendicular to a plane of each layer of the free layer assembly. A spacer layer is between the reference layer and the free layer, and a signal enhancement layer is exchange coupled to the free layer assembly on a side opposite the spacer layer.
    Type: Application
    Filed: March 15, 2011
    Publication date: July 7, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Song S. Xue, Zheng Gao, Shaoping Li, Kaizhong Gao, Dimitar V. Dimitrov, Konstantin Nikolaev, Patrick J. Ryan
  • Publication number: 20110134572
    Abstract: A trilayer magnetoresistive sensor includes first and second ferromagnetic layers separated by a nonmagnetic layer. A high coercivity permanent magnet bias element biases the first ferromagnetic layer in a first direction. A high moment permanent magnet bias element biases the second ferromagnetic layer in a second direction substantially orthogonal to the first direction.
    Type: Application
    Filed: December 4, 2009
    Publication date: June 9, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Jiaoming Qiu, Yonghua Chen, Kaizhong Gao
  • Publication number: 20110121418
    Abstract: A free ferromagnetic data storage layer of an MRAM cell is coupled to a free ferromagnetic stabilization layer, which stabilization layer is directly electrically coupled to a contact electrode, on one side, and is separated from the free ferromagnetic data storage layer, on an opposite side, by a spacer layer. The spacer layer provides for the coupling between the two free layers, which coupling is one of: a ferromagnetic coupling and an antiferromagnetic coupling.
    Type: Application
    Filed: January 27, 2011
    Publication date: May 26, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Haiwen Xi, Kaizhong Gao, Dimitar V. Dimitrov, Song S. Xue
  • Publication number: 20110109999
    Abstract: An apparatus and associated method for a magnetic shield structure for data transduction from a recordable media in a data storage device. Various embodiments of the present invention are generally directed to a data transducer and a magnetic shield structure comprising a write shield magnetic material constructed of exchange decoupled material.
    Type: Application
    Filed: November 12, 2009
    Publication date: May 12, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Mourad Benakli, Kirill Rivkin, Kaizhong Gao, James Wessel, Ming Sun, Ibro Tabakovic, Mark Thomas Kief
  • Patent number: 7935435
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Publication number: 20110089510
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Application
    Filed: December 23, 2010
    Publication date: April 21, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Publication number: 20110090588
    Abstract: A magnetic recording head comprises a write pole tip adjacent to an air bearing surface and a return pole. In addition, a near field transducer is positioned adjacent the write pole in order to produce near field radiation to heat a portion of a recording medium to facilitate switching by the magnetic write pole. The near field transducer is a reverse optical near field transducer with internal bevel structures that enhance the magnetic write field intensity.
    Type: Application
    Filed: October 20, 2009
    Publication date: April 21, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Xuhui Jin, Arkadi Goulakov
  • Patent number: 7929258
    Abstract: A magnetic sensor includes a reference layer having a first magnetization direction and a free layer assembly having an effective magnetization direction substantially perpendicular to the first magnetization direction and substantially perpendicular to a plane of each layer of the free layer assembly. A spacer layer is between the reference layer and the free layer, and a signal enhancement layer is exchange coupled to the free layer assembly on a side opposite the spacer layer.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: April 19, 2011
    Assignee: Seagate Technology LLC
    Inventors: Song S. Xue, Zheng Gao, Shaoping Li, Kaizhong Gao, Dimitar V. Dimitrov, Konstantin Nikolaev, Patrick J. Ryan
  • Publication number: 20110076516
    Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.
    Type: Application
    Filed: December 7, 2010
    Publication date: March 31, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang
  • Publication number: 20110069537
    Abstract: The present invention relates to a memory cell including a first reference layer having a first magnetization with a first magnetization direction and a second reference layer having a second magnetization with a second magnetization direction substantially perpendicular to the first magnetization direction. A storage layer is disposed between the first reference layer and second reference layer and has a third magnetization direction about 45° from the first magnetization direction and about 135° from the second magnetization direction when the memory cell is in a first data state, and a fourth magnetization direction opposite the third magnetization direction when the memory cell is in a second data state.
    Type: Application
    Filed: December 1, 2010
    Publication date: March 24, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Haiwen Xi, Yiming Shi, Song S. Xue, Sining Mao
  • Publication number: 20110050211
    Abstract: A magnetic sensor comprises a sensor stack and magnetic bias elements positioned adjacent each side of the sensor stack. The sensor stack and bias elements have substantially trapezoidal shapes.
    Type: Application
    Filed: August 26, 2009
    Publication date: March 3, 2011
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Jiaoming Qiu, Lei Wang, Yonghua Chen
  • Publication number: 20110051294
    Abstract: A magnetic sensor or magnetoresistive read head comprises a sensor stack and magnetic bias elements positioned adjacent each side of the sensor stack. The sensor stack and bias elements have non-rectangular shapes, such as substantially trapezoidal or parallelogram shapes having non-perpendicular corners. In some embodiments, the sensor stack and bias elements have a shape that stabilizes a “C” state or “S” state magnetization pattern.
    Type: Application
    Filed: March 19, 2010
    Publication date: March 3, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Lei Wang, Jiaoming Qiu, Yonghua Chen
  • Publication number: 20110038072
    Abstract: Data storage systems are provided. Data storage systems illustratively include a recording head having a writing element and a bit patterned medium having a plurality of media dots. In some embodiments, the plurality of media dots pass the recording head at a media dot frequency. In some embodiments, the writing element writes data to the bit patterned media at a writing frequency that is less than the media dot frequency.
    Type: Application
    Filed: August 11, 2009
    Publication date: February 17, 2011
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Housan Dakroub
  • Patent number: 7880209
    Abstract: A free ferromagnetic data storage layer of an MRAM cell is coupled to a free ferromagnetic stabilization layer, which stabilization layer is directly electrically coupled to a contact electrode, on one side, and is separated from the free ferromagnetic data storage layer, on an opposite side, by a spacer layer. The spacer layer provides for the coupling between the two free layers, which coupling is one of: a ferromagnetic coupling and an antiferromagnetic coupling.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: February 1, 2011
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Kaizhong Gao, Dimitar V. Dimitrov, Song S. Xue
  • Publication number: 20110019300
    Abstract: Data storage systems are provided. Data storage systems illustratively include a writing element and a recording medium. In some embodiments, the writing element generates first and second magnetization fields that respectively record first and second magnetization patterns to the recording medium. In some embodiments, the writing element is de-saturated between recording the first and second magnetization patterns.
    Type: Application
    Filed: July 21, 2009
    Publication date: January 27, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Olle Gunnar Heinonen, Jianhua Xue, Wenzhong Zhu
  • Publication number: 20110007422
    Abstract: A transducer includes magnetic material formed on a substrate that is shaped to include a trailing edge, a leading edge and a pair of opposing sidewalls extending between the trailing edge and the leading edge. A layer of protective material is positioned in contact with each of the pair of sidewalls of the shaped magnetic material. Backfill material surrounds the protective material on each of the pair of sidewalls of the shaped magnetic material.
    Type: Application
    Filed: July 13, 2009
    Publication date: January 13, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Alexey V. Nazarov, Vladyslav Alexandrovich Vasko, Olle Gunnar Heinonen, Lijuan Zou, Thomas R. Boonstra, Xilin Peng, Kaizhong Gao