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).
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Publication number: 20220148619Abstract: 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: ApplicationFiled: January 28, 2022Publication date: May 12, 2022Applicant: Western Digital Technologies, Inc.Inventors: James Mac FREITAG, Susumu OKAMURA, Alexander GONCHAROV, Zheng GAO
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Patent number: 11289118Abstract: 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: GrantFiled: February 24, 2021Date of Patent: March 29, 2022Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Christian Kaiser, Andrew Chen, Zheng Gao, Susumu Okamura, James Mac Freitag
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Patent number: 11283006Abstract: 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: GrantFiled: May 5, 2020Date of Patent: March 22, 2022Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: James Mac Freitag, Zheng Gao
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Patent number: 11257514Abstract: 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: GrantFiled: June 25, 2020Date of Patent: February 22, 2022Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: James Mac Freitag, Susumu Okamura, Alexander Goncharov, Zheng Gao
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Publication number: 20210407534Abstract: 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: ApplicationFiled: June 25, 2020Publication date: December 30, 2021Inventors: James Mac FREITAG, Susumu OKAMURA, Alexander GONCHAROV, Zheng GAO
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Patent number: 11211083Abstract: 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: GrantFiled: June 24, 2020Date of Patent: December 28, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Yuankai Zheng, Zheng Gao, Christian Kaiser, Zhitao Diao, Susumu Okamura, James Mac Freitag, Alexander Goncharov
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Publication number: 20210390977Abstract: 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: ApplicationFiled: August 31, 2021Publication date: December 16, 2021Applicant: Western Digital Technologies, Inc.Inventors: James Mac FREITAG, Zheng GAO, Susumu OKAMURA, Brian R. YORK
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Patent number: 11127420Abstract: 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: GrantFiled: June 24, 2019Date of Patent: September 21, 2021Assignee: Western Digital Technologies, Inc.Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Brian York
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Publication number: 20210233560Abstract: 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: ApplicationFiled: April 12, 2021Publication date: July 29, 2021Applicant: Western Digital Technologies, Inc.Inventors: James Mac FREITAG, Zheng GAO, Masahiko HASHIMOTO, Sangmun OH
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Patent number: 10997993Abstract: 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: GrantFiled: February 14, 2020Date of Patent: May 4, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: James Mac Freitag, Zheng Gao, Masahiko Hashimoto, Sangmun Oh
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Patent number: 10997992Abstract: 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: GrantFiled: September 16, 2019Date of Patent: May 4, 2021Assignee: Western Digital Technologies, Inc.Inventors: James Mac Freitag, Susumu Okamura, Masahiko Hashimoto, Zheng Gao
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Patent number: 10950258Abstract: 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: GrantFiled: May 26, 2020Date of Patent: March 16, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Zheng Gao, Susumu Okamura, James Mac Freitag
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Patent number: 10950260Abstract: 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: GrantFiled: April 17, 2020Date of Patent: March 16, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: James Mac Freitag, Zheng Gao
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Patent number: 10943611Abstract: 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: GrantFiled: March 31, 2020Date of Patent: March 9, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Yongchul Ahn, Aron Pentek, Amanda Baer
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Patent number: 10872627Abstract: 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: GrantFiled: August 12, 2020Date of Patent: December 22, 2020Assignee: 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
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Patent number: 10867625Abstract: 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: GrantFiled: February 27, 2020Date of Patent: December 15, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INCInventors: James Mac Freitag, Zheng Gao, Masahiko Hashimoto, Sangmun Oh, Hua Ai Zeng
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Publication number: 20200372929Abstract: 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: ApplicationFiled: August 12, 2020Publication date: November 26, 2020Inventors: Quang LE, Yongchul AHN, Susumu OKAMURA, Zheng GAO, Alexander GONCHAROV, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, James Mac FREITAG
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Patent number: 10839833Abstract: 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: GrantFiled: February 27, 2020Date of Patent: November 17, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INCInventors: James Mac Freitag, Masahiko Hashimoto, Zheng Gao, Susumu Okamura
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Patent number: 10762917Abstract: 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: GrantFiled: March 28, 2019Date of Patent: September 1, 2020Assignee: 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
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Patent number: 10734013Abstract: 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: GrantFiled: February 15, 2019Date of Patent: August 4, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Zheng Gao, Masahiko Hashimoto, Susumu Okamura, James Mac Freitag