Patents by Inventor James Mac Freitag

James Mac Freitag has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220148619
    Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.
    Type: Application
    Filed: January 28, 2022
    Publication date: May 12, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Susumu OKAMURA, Alexander GONCHAROV, Zheng GAO
  • Patent number: 11289118
    Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and spintronic device disposed between the main pole and the trailing shield. The spintronic device comprises a negative polarization layer (NPL) disposed on the main pole, the NPL comprising FeTi, FeV, FeCr, or FeN, an interface layer disposed on the NPL, the interface layer comprising V, Cr, or Ru, a spacer layer disposed on the interface layer, and a spin torque layer (FGL) disposed on the spacer layer. When current is applied to the spintronic device, the NPL and a first interface disposed between the NPL and the interface layer have a negative spin polarization while the FGL and a second interface disposed between the FGL and the spacer layer have a positive spin polarization.
    Type: Grant
    Filed: February 24, 2021
    Date of Patent: March 29, 2022
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Christian Kaiser, Andrew Chen, Zheng Gao, Susumu Okamura, James Mac Freitag
  • Patent number: 11283006
    Abstract: The present disclosure generally relates to magnetoresistive device apparatus and methods. The magnetoresistive device includes a read head. The read head is a tunneling magnetoresistive reader that includes a multilayer free layer structure. The multilayer structure includes one or more layers of Co or FCC FeCo sandwiched between a BCC CoFe50 nanolayer and an amorphous CoFeB layer. The one or more layers of Co or FCC FeCo create nanocrystalline disorder that allows the thickness of the amorphous CoFeB layer to be reduced while retaining or even improving TMR and reducing the interlayer coupling field.
    Type: Grant
    Filed: May 5, 2020
    Date of Patent: March 22, 2022
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Zheng Gao
  • Patent number: 11257514
    Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head includes a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.
    Type: Grant
    Filed: June 25, 2020
    Date of Patent: February 22, 2022
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Susumu Okamura, Alexander Goncharov, Zheng Gao
  • Publication number: 20210407534
    Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.
    Type: Application
    Filed: June 25, 2020
    Publication date: December 30, 2021
    Inventors: James Mac FREITAG, Susumu OKAMURA, Alexander GONCHAROV, Zheng GAO
  • Patent number: 11211083
    Abstract: Embodiments of the present disclosure generally relate to a write head for a magnetic recording device. The write head includes a spin torque oscillator (STO) that has a seed layer formed on a write pole, a spin polarization layer (SPL) formed on the seed layer, a first spacer layer formed on the SPL, a field generation layer (FGL) formed on the first spacer layer, a second spacer layer formed on the FGL, and a notch formed on the second spacer layer. The FGL and the notch are antiferromagnetically coupled through the second spacer layer and thus increases the FGL angle and improves the write capabilities of the write head.
    Type: Grant
    Filed: June 24, 2020
    Date of Patent: December 28, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Yuankai Zheng, Zheng Gao, Christian Kaiser, Zhitao Diao, Susumu Okamura, James Mac Freitag, Alexander Goncharov
  • Publication number: 20210390977
    Abstract: Certain embodiments are directed to a spin torque oscillator (STO) device in a microwave assisted magnetic recording (MAMR) device. The magnetic recording head includes a seed layer, a spin polarization layer over the seed layer, a spacer layer over the spin polarization layer, and a field generation layer is over the spacer layer. In one embodiment, the seed layer comprises a tantalum alloy layer. In another embodiment, the seed layer comprises a template layer and a damping reduction layer over the template layer. In yet another embodiment, the seed layer comprises a texture reset layer, a template layer on the texture reset layer, and a damping reduction layer on the template layer.
    Type: Application
    Filed: August 31, 2021
    Publication date: December 16, 2021
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Zheng GAO, Susumu OKAMURA, Brian R. YORK
  • Patent number: 11127420
    Abstract: Certain embodiments are directed to a spin torque oscillator (STO) device in a microwave assisted magnetic recording (MAMR) device. The magnetic recording head includes a seed layer, a spin polarization layer over the seed layer, a spacer layer over the spin polarization layer, and a field generation layer is over the spacer layer. In one embodiment, the seed layer comprises a tantalum alloy layer. In another embodiment, the seed layer comprises a template layer and a damping reduction layer over the template layer. In yet another embodiment, the seed layer comprises a texture reset layer, a template layer on the texture reset layer, and a damping reduction layer on the template layer.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: September 21, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Brian York
  • Publication number: 20210233560
    Abstract: A magnetic recording write head and system has a spin-torque oscillator (STO) located between the write head's write pole and trailing shield. The STO's ferromagnetic free layer is located near the write pole with a multilayer seed layer between the write pole and the free layer. The STO's nonmagnetic spacer layer is between the free layer and the STO's ferromagnetic polarizer. The polarizer may be the trailing shield of the write head, one or more separate polarizer layers, or combinations thereof. The STO electrical circuitry causes electron flow from the write pole to the trailing shield. The multilayer seed layer removes the spin polarization of electrons from the write pole, which enables electrons reflected from the polarizer layer to become spin polarized, which creates the spin transfer torque on the magnetization of the free layer. The multilayer seed layer includes a Mn or a Mn-alloy layer.
    Type: Application
    Filed: April 12, 2021
    Publication date: July 29, 2021
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Zheng GAO, Masahiko HASHIMOTO, Sangmun OH
  • Patent number: 10997993
    Abstract: A magnetic recording write head and system has a spin-torque oscillator (STO) located between the write head's write pole and trailing shield. The STO's ferromagnetic free layer is located near the write pole with a multilayer seed layer between the write pole and the free layer. The STO's nonmagnetic spacer layer is between the free layer and the STO's ferromagnetic polarizer. The polarizer may be the trailing shield of the write head, one or more separate polarizer layers, or combinations thereof. The STO electrical circuitry causes electron flow from the write pole to the trailing shield. The multilayer seed layer removes the spin polarization of electrons from the write pole, which enables electrons reflected from the polarizer layer to become spin polarized, which creates the spin transfer torque on the magnetization of the free layer. The multilayer seed layer includes a Mn or a Mn-alloy layer.
    Type: Grant
    Filed: February 14, 2020
    Date of Patent: May 4, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Zheng Gao, Masahiko Hashimoto, Sangmun Oh
  • Patent number: 10997992
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.
    Type: Grant
    Filed: September 16, 2019
    Date of Patent: May 4, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Susumu Okamura, Masahiko Hashimoto, Zheng Gao
  • Patent number: 10950258
    Abstract: Aspects of the present disclosure relate to spin torque oscillator (STO) and methods, such as spin torque oscillators used in write heads of magnetic media drives. The STO includes a seed layer, a spin polarization layer (SPL), a spacer layer, a field generation layer (FGL), a capping layer. An insertion layer is disposed within the STO. The insertion layer increases the negative Hk. The insertion layer may be located between the FGL and the capping layer, as well as between the FGL and the spacer layer. For a reverse STO, the insertion layer may be disposed between the FGL and the seed layer, as well as between the FGL and the spacer layer.
    Type: Grant
    Filed: May 26, 2020
    Date of Patent: March 16, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, Susumu Okamura, James Mac Freitag
  • Patent number: 10950260
    Abstract: A free layer comprising a bilayer (e.g., a first and a second layer) with an amorphous insertion layer in between the bilayer. The free layer includes a ferromagnetic nanolayer between the bilayer and a barrier layer. The magnetostriction of the free layer is tunable by varying the thicknesses of each of the first and the second layers. The free layer can be part of a magnetoresistive device with a reference layer or with another free layer.
    Type: Grant
    Filed: April 17, 2020
    Date of Patent: March 16, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Zheng Gao
  • Patent number: 10943611
    Abstract: In one embodiment, a write head includes a spin polarization layer (SPL) over a seed layer. A spacer layer is over the SPL. A trailing shield is over the spacer layer. The spacer layer forms a first interface between the spacer layer and the trailing shield and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface. In another embodiment, a write head includes a SPL over a spacer layer. A capping layer is over the SPL. A trailing shield is over the capping layer. The spacer layer forms a first interface between the spacer layer and the main pole and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: March 9, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Yongchul Ahn, Aron Pentek, Amanda Baer
  • Patent number: 10872627
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Grant
    Filed: August 12, 2020
    Date of Patent: December 22, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Susumu Okamura, Zheng Gao, Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, James Mac Freitag
  • Patent number: 10867625
    Abstract: A spin transfer torque (STT) device has a free ferromagnetic layer that includes a Heusler alloy layer and a template layer beneath and in contact with the Heusler alloy layer. The template layer may be a ferromagnetic alloy comprising one or more of Co, Ni and Fe and the element X, where X is selected from one or more of Ta, B, Hf, Zr, W, Nb and Mo. A CoFe nanolayer may be formed below and in contact with the template layer. The STT device may be a spin-torque oscillator (STO), like a STO incorporated into the write head of a magnetic recording disk drive. The STT device may also be a STT in-plane or perpendicular magnetic tunnel junction (MTJ) cell for magnetic random access memory (MRAM). The template layer reduces the critical current density of the STT device.
    Type: Grant
    Filed: February 27, 2020
    Date of Patent: December 15, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC
    Inventors: James Mac Freitag, Zheng Gao, Masahiko Hashimoto, Sangmun Oh, Hua Ai Zeng
  • Publication number: 20200372929
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Application
    Filed: August 12, 2020
    Publication date: November 26, 2020
    Inventors: Quang LE, Yongchul AHN, Susumu OKAMURA, Zheng GAO, Alexander GONCHAROV, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, James Mac FREITAG
  • Patent number: 10839833
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic polarizer layer near the substrate, a ferromagnetic free layer, and a nonmagnetic spacer layer between the ferromagnetic polarizer layer and the ferromagnetic free layer. A multilayer structure is located between the substrate and the ferromagnetic polarizer layer. The multilayer structure includes a metal or metal alloy seed layer for the ferromagnetic polarizer layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the write pole and thus reduces undesirable spin pumping of the ferromagnetic polarizer layer.
    Type: Grant
    Filed: February 27, 2020
    Date of Patent: November 17, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC
    Inventors: James Mac Freitag, Masahiko Hashimoto, Zheng Gao, Susumu Okamura
  • Patent number: 10762917
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: September 1, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Susumu Okamura, Zheng Gao, Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, James Mac Freitag
  • Patent number: 10734013
    Abstract: Spin transfer torque (STT) devices with multilayer seed layers that can be used in magnetic recording and memory are provided. One such STT device includes a substrate, and a stack of layers formed on the substrate, where the stack includes a first seed layer directly on the substrate and including Cr, a second seed layer on the first seed layer and including Ta, a ferromagnetic free layer on the second seed layer; a ferromagnetic polarizing layer, and a nonmagnetic spacer layer between the free layer and the polarizing layer. One such method includes fabricating the STT device.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: August 4, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, Masahiko Hashimoto, Susumu Okamura, James Mac Freitag