Patents by Inventor Yo Sato

Yo Sato 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: 10037772
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.
    Type: Grant
    Filed: September 25, 2017
    Date of Patent: July 31, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Masashige Sato, Keiichi Nagasaka, Yo Sato
  • Patent number: 9990943
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole and a texture control layer (TCL), a seed control layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO has a crystallographic preferred growth orientation and includes a spin polarized layer (SPL). The TCL may include a Cu layer.
    Type: Grant
    Filed: August 1, 2017
    Date of Patent: June 5, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Yo Sato, Keiichi Nagasaka, Masashige Sato
  • Publication number: 20180025746
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.
    Type: Application
    Filed: September 25, 2017
    Publication date: January 25, 2018
    Inventors: Susumu Okamura, Masashige Sato, Keiichi Nagasaka, Yo Sato
  • Publication number: 20180005651
    Abstract: A magnetic write head having a spin torque oscillator with a magnetic field sensor for accurately determining magnetic field oscillation frequency. The spin torque oscillator has one or more tunnel junction (TMR) sensors formed at the side of the spin torque oscillator. The TMR sensor advantageously detects a magnetic field signal that is an additive signal of both fields from the spin polarization layer and the magnetic field generation layer, thereby providing efficient detection of magnetic field and associated oscillation frequency.
    Type: Application
    Filed: June 30, 2016
    Publication date: January 4, 2018
    Inventors: Masashige Sato, Susumu Okamura, Yo Sato, Keiichi Nagasaka
  • Patent number: 9858952
    Abstract: A magnetic write head having a spin torque oscillator with a magnetic field sensor for accurately determining magnetic field oscillation frequency. The spin torque oscillator has one or more tunnel junction (TMR) sensors formed at the side of the spin torque oscillator. The TMR sensor advantageously detects a magnetic field signal that is an additive signal of both fields from the spin polarization layer and the magnetic field generation layer, thereby providing efficient detection of magnetic field and associated oscillation frequency.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: January 2, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Masashige Sato, Susumu Okamura, Yo Sato, Keiichi Nagasaka
  • Publication number: 20170365282
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole and a texture control layer (TCL), a seed control layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO has a crystallographic preferred growth orientation and includes a spin polarized layer (SPL). The TCL may include a Cu layer.
    Type: Application
    Filed: August 1, 2017
    Publication date: December 21, 2017
    Inventors: Susumu Okamura, Yo Sato, Keiichi Nagasaka, Masashige Sato
  • Patent number: 9805746
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: October 31, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Masashige Sato, Keiichi Nagasaka, Yo Sato
  • Patent number: 9728210
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole and a texture control layer (TCL), a seed control layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO has a crystallographic preferred growth orientation and includes a spin polarized layer (SPL). The TCL may include a Cu layer.
    Type: Grant
    Filed: November 25, 2015
    Date of Patent: August 8, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Yo Sato, Keiichi Nagasaka, Masashige Sato
  • Publication number: 20170148474
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole and a texture control layer (TCL), a seed control layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO has a crystallographic preferred growth orientation and includes a spin polarized layer (SPL). The TCL may include a Cu layer.
    Type: Application
    Filed: November 25, 2015
    Publication date: May 25, 2017
    Inventors: Susumu Okamura, Yo Sato, Keiichi Nagasaka, Masashige Sato
  • Patent number: 9437222
    Abstract: A magnetic oscillator for use in Microwave Assisted Magnetic Recording (MAMR). The magnetic oscillator can be a spin torque oscillator and includes a magnetic spin polarization layer, a magnetic field generation layer and a non-magnetic intermediate layer sandwiched between the magnetic spin polarization layer and the magnetic field generation layer. The non-magnetic intermediate layer is constructed of a material that provides improved performance, increased lifespan and thermal robustness. The magnetic intermediate layer is constructed of an alloy of Ag and an element X. More preferably the element X can be Sn or Zn.
    Type: Grant
    Filed: May 30, 2015
    Date of Patent: September 6, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Susumu Okamura, Masao Shiimoto, Katsuro Watanabe, Masashige Sato, Keiichi Nagasaka, Yo Sato, Masukazu Igarashi
  • Patent number: 9406315
    Abstract: The embodiments disclosed generally relate to an STO structure for a magnetic head. The STO structure has an FGL having a greater thickness than the SPL. The SPL may have multiple layers. In one embodiment, a MAMR head comprises a main pole; a trailing shield; and an STO coupled between the main pole and the trailing shield. The STO includes: a first magnetic layer having a first thickness; a non-magnetic spacer layer coupled to the first magnetic layer; and a second magnetic layer having a second thickness and coupled to the non-magnetic spacer layer, wherein the first thickness is greater than the second thickness, wherein a current is charged from the first magnetic layer to the second magnetic layer, and wherein a vertical magnetic anisotropy field of the second magnetic film is less than 0 kOe.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: August 2, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Shiimoto, Masukaza Igarashi, Keiichi Nagasaka, Yo Sato
  • Patent number: 9378759
    Abstract: Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: June 28, 2016
    Assignee: HGST NETHERLANDS B.V.
    Inventors: Keiichi Nagasaka, Yo Sato, Masashige Sato, Susumu Okamura, Masato Shiimoto, Masukazu Igarashi
  • Publication number: 20160148627
    Abstract: Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.
    Type: Application
    Filed: November 20, 2014
    Publication date: May 26, 2016
    Inventors: Keiichi NAGASAKA, Yo SATO, Masashige SATO, Susumu OKAMURA, Masato SHIIMOTO, Masukazu IGARASHI
  • Patent number: 9336797
    Abstract: The present disclosure generally relates to a high-frequency oscillator for use in a recording device having a microwave-assisted magnetic recording head. The microwave-assisted magnetic recording head achieves a large assist effect by using an extended spin torque oscillator disposed between a main magnetic pole and a pole opposite the main magnetic pole. The spin torque oscillator obtains a strong high-frequency magnetic field and comprises a first non-magnetic spin scatterer, a reference layer, a first non-magnetic spin transfer layer, a first magnetic field generating layer, a second non-magnetic spin transfer layer, a second magnetic field generating layer, and a second non-magnetic spin scatterer. The spin torque oscillator has a drive current flowing though in the direction from the first magnetic field generating layer to the reference layer.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: May 10, 2016
    Assignee: HGST NETHERLANDS B.V.
    Inventors: Masukazu Igarashi, Masato Matsubara, Keiichi Nagasaka, Yo Sato, Masato Shiimoto, Masashige Sato
  • Patent number: 9311934
    Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO and a current switching system electrically coupled to the STO. The current switching system can be used to optimize the STO frequency by changing the STO bias polarity, i.e., by changing the direction of the current flowing to the STO. As a result, the difference between the STO frequency and the magnetic media frequency is minimized, which improves recording capability of the MAMR head.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: April 12, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Shiimoto, Masashige Sato, Masukazu Igarashi, Yo Sato, Masato Matsubara
  • Patent number: 9305574
    Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first magnetic layer, a second magnetic layer and an interlayer disposed between the first and second magnetic layers. One of the first and second magnetic layers is made of a negative polarization material while the other magnetic layer is made of a positive polarization material. As a result, the magnetizations in the first and second magnetic layers are in the same direction when in oscillation, which suppresses the partial cancellation of the magnetizations in the first and second magnetic layers and strengthens the AC magnetic field.
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: April 5, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Keiichi Nagasaka, Yo Sato, Masato Shiimoto, Masashige Sato, Masukazu Igarashi, Susumu Okamura
  • Publication number: 20160086623
    Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first magnetic layer, a second magnetic layer and an interlayer disposed between the first and second magnetic layers. One of the first and second magnetic layers is made of a negative polarization material while the other magnetic layer is made of a positive polarization material. As a result, the magnetizations in the first and second magnetic layers are in the same direction when in oscillation, which suppresses the partial cancellation of the magnetizations in the first and second magnetic layers and strengthens the AC magnetic field.
    Type: Application
    Filed: September 23, 2014
    Publication date: March 24, 2016
    Inventors: Keiichi NAGASAKA, Yo SATO, Masato SHIIMOTO, Masashige SATO, Masukazu IGARASHI, Susumu OKAMURA
  • Patent number: 9230569
    Abstract: In one embodiment, a magnetic head includes a main magnetic pole positioned configured to generate a writing magnetic field when current is applied to a write coil, and a spin torque oscillator (STO) located adjacent the main magnetic pole, the STO being configured to generate a high frequency magnetic field when current is applied thereto, wherein the high frequency magnetic field is generated simultaneously to the writing magnetic field to assist in reversing magnetization of a magnetic recording medium. The STO includes: a spin polarization layer (SPL), a field generation layer (FGL) positioned adjacent the SPL, and one or more interlayers positioned between the SPL and the FGL, and a magnetization easy axis of the SPL is positioned in an in-plane direction such that the SPL has no perpendicular magnetic anisotropy.
    Type: Grant
    Filed: November 26, 2014
    Date of Patent: January 5, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Shimoto, Masukazu Igarashi, Keiichi Nagasaka, Yo Sato, Susumu Okamura, Masashige Sato
  • Patent number: 9230597
    Abstract: In one embodiment, a magnetic head includes a main pole configured to write data to a magnetic medium, a trailing shield positioned on a trailing side of the main pole, and a STO between the main pole and the trailing shield, wherein the STO includes a laminated structure having a FGL, a spun polarization layer (SPL), and a non-magnetic spacer positioned between the FGL and the SPL, wherein the FGL includes a laminated structure having one or more layers of a CoFe alloy and a Heusler alloy alternately laminated in this order from an end of the FGL closest to the non-magnetic spacer. In another embodiment, a method is presented for forming such a magnetic head utilizing a FGL that includes a laminated structure baying layers of a CoFe alloy and a Heusler alloy alternately laminated in this order from an end of the FGL closest to the non-magnetic spacer.
    Type: Grant
    Filed: November 1, 2013
    Date of Patent: January 5, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Shimoto, Keiichi Nagasaka, Masato Matsubara, Yo Sato
  • Patent number: D848918
    Type: Grant
    Filed: January 24, 2018
    Date of Patent: May 21, 2019
    Assignee: MAZDA MOTOR CORPORATION
    Inventors: Seiji Hisada, Shigeyuki Sato, Mitsuaki Maekawa, Yo Kitamura, Isao Fujioka