Patents by Inventor Hoan Cong Ho

Hoan Cong Ho 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: 20240096368
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium. A magnetic recording medium includes a substrate, a heat sink layer on the substrate, and an underlayer on the heat sink layer. The underlayer includes an amount of an electrically conductive material between about 20 mole percent (mol %) and about 100 mol %. The magnetic recording medium further includes the plurality of magnetic recording layers on the underlayer. The plurality of magnetic recording layers includes a first magnetic recording layer that comprises FePt—Ag—X, wherein X is an oxide.
    Type: Application
    Filed: September 15, 2022
    Publication date: March 21, 2024
    Inventors: Hua Yuan, Hoan Cong Ho, Paul Christopher Dorsey
  • Publication number: 20240071416
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium. The HAMR medium includes a substrate, a heat sink layer on the substrate, and a plurality of magnetic recording layers on the heat sink layer. The plurality of magnetic recording layers includes a first magnetic layer and a second magnetic layer disposed on the first magnetic layer. The second magnetic layer includes FePt—Ag—Cu—X, wherein X is a segregant comprising BN. The HAMR medium can use BN-based segregants to improve a thermal gradient of the HAMR medium for better areal density capability (ADC) and enable the use of a MgO underlayer with reduced thickness.
    Type: Application
    Filed: August 25, 2022
    Publication date: February 29, 2024
    Inventors: Hoan Cong Ho, Tomoko Seki, Paul Christopher Dorsey
  • Publication number: 20240055019
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a magnetic recording layer on a magnesium oxide-titanium oxide (MTO) underlayer, where the MTO underlayer includes an additive material that chemically bonds with titanium. In some examples, the additive material includes iron-oxide, iron, carbon, or various aluminum oxides. By providing the additive material to the MTO that chemically bonds with the titanium of the MTO, diffusion of titanium from the MTO underlayer into the magnetic recording layer is mitigated to provide an improved recording layer that achieves improved areal densities. In some embodiments, an additional magnesium oxide-nitrogen underlayer is also provided, which may include more of the additive material.
    Type: Application
    Filed: August 11, 2022
    Publication date: February 15, 2024
    Inventors: Hoan Cong Ho, Hua Yuan, Tomoko Seki, Paul Christopher Dorsey
  • Patent number: 11900978
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a magnetic recording layer on a magnesium oxide-titanium oxide (MTO) underlayer, where the MTO underlayer includes an additive material that chemically bonds with titanium. In some examples, the additive material includes iron-oxide, iron, carbon, or various aluminum oxides. By providing the additive material to the MTO that chemically bonds with the titanium of the MTO, diffusion of titanium from the MTO underlayer into the magnetic recording layer is mitigated to provide an improved recording layer that achieves improved areal densities. In some embodiments, an additional magnesium oxide-nitrogen underlayer is also provided, which may include more of the additive material.
    Type: Grant
    Filed: August 11, 2022
    Date of Patent: February 13, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hoan Cong Ho, Hua Yuan, Tomoko Seki, Paul Christopher Dorsey
  • Patent number: 11869556
    Abstract: A heat-assisted magnetic recording (HAMR) disk has a magnetic recording layer (typically a FePt chemically-ordered alloy), a seed-thermal barrier layer (typically MgO) below the recording layer, a heat-sink layer, and an optical-coupling multilayer of alternating plasmonic and non-plasmonic materials between the heat-sink layer and the seed-thermal barrier layer. Unlike a heat sink layer, the multilayer has very low in-plane and out-of-plane thermal conductivity and thus does not function as a heat sink layer. The multilayer's low thermal conductivity allows the multilayer to also function as a thermal barrier. Due to the plasmonic materials in the multilayer it provides excellent optical coupling with the near-field transducer (NFT) of the HAMR disk drive.
    Type: Grant
    Filed: August 29, 2022
    Date of Patent: January 9, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Pierre-Olivier Jubert, Paul Christopher Dorsey, Hoan Cong Ho
  • Publication number: 20230048634
    Abstract: A heat-assisted magnetic recording (HAMR) disk has a magnetic recording layer (typically a FePt chemically-ordered alloy), a seed-thermal barrier layer (typically MgO) below the recording layer, a heat-sink layer, and an optical-coupling multilayer of alternating plasmonic and non-plasmonic materials between the heat-sink layer and the seed-thermal barrier layer. Unlike a heat sink layer, the multilayer has very low in-plane and out-of-plane thermal conductivity and thus does not function as a heat sink layer. The multilayer's low thermal conductivity allows the multilayer to also function as a thermal barrier. Due to the plasmonic materials in the multilayer it provides excellent optical coupling with the near-field transducer (NFT) of the HAMR disk drive.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 16, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Pierre-Olivier JUBERT, Paul Christopher DORSEY, Hoan Cong HO
  • Publication number: 20230005503
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a magnesium (Mg) trapping layer that is configured to mitigate Mg migration in the HAMR medium so as to prevent near field transducer (NFT) damage caused by dissociated Mg reacting with a compound used in the NFT. In one example, the HAMR medium can include a substrate, a seed layer on the substrate and including MgO, a magnetic recording layer on the seed layer, and a Mg trapping layer on the substrate and configured to mitigate Mg migration from the seed layer to a surface of the HAMR medium above the magnetic recording layer.
    Type: Application
    Filed: July 1, 2021
    Publication date: January 5, 2023
    Inventors: Takashi Iwanami, Kouji Matsuda, Junguo Xu, Kenji Tasaka, Hoan Cong Ho, Tomoko Seki, Paul Christopher Dorsey, Masayoshi Shimokoshi
  • Patent number: 11521648
    Abstract: A heat-assisted magnetic recording (HAMR) medium has a multilayered underlayer between the heat-sink layer and the recording layer. One embodiment of the underlayer is a multilayer of a thermal barrier layer consisting essentially of MgO and TiO, and a seed layer containing MgO and nitrogen (N) directly on the thermal barrier layer, with the recording layer on and in contact with the seed layer. The interface between the thermal barrier layer and the seed layer contains Ti and N, some of which may be present as TiN to act as a diffusion barrier to prevent diffusion of the Ti into the recording layer. The Ti-containing thermal barrier layer has a higher thermal resistivity than the conventional MgO thermal barrier/seed layer and thus allows for reduced laser power to the recording layer while still achieving a high thermal gradient at the recording layer.
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: December 6, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hoan Cong Ho, Paul Christopher Dorsey, Tomoko Seki
  • Patent number: 11437064
    Abstract: A heat-assisted magnetic recording (HAMR) disk has a magnetic recording layer (typically a FePt chemically-ordered alloy), a seed-thermal barrier layer (typically MgO) below the recording layer, a heat-sink layer, and an optical-coupling multilayer of alternating plasmonic and non-plasmonic materials between the heat-sink layer and the seed-thermal barrier layer. Unlike a heat sink layer, the multilayer has very low in-plane and out-of-plane thermal conductivity and thus does not function as a heat sink layer. The multilayer's low thermal conductivity allows the multilayer to also function as a thermal barrier. Due to the plasmonic materials in the multilayer it provides excellent optical coupling with the near-field transducer (NFT) of the HAMR disk drive.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: September 6, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Pierre-Olivier Jubert, Paul Christopher Dorsey, Hoan Cong Ho
  • Publication number: 20220139422
    Abstract: A heat-assisted magnetic recording (HAMR) medium has a multilayered underlayer between the heat-sink layer and the recording layer. One embodiment of the underlayer is a multilayer of a thermal barrier layer consisting essentially of MgO and TiO, and a seed layer containing MgO and nitrogen (N) directly on the thermal barrier layer, with the recording layer on and in contact with the seed layer. The interface between the thermal barrier layer and the seed layer contains Ti and N, some of which may be present as TiN to act as a diffusion barrier to prevent diffusion of the Ti into the recording layer. The Ti-containing thermal barrier layer has a higher thermal resistivity than the conventional MgO thermal barrier/seed layer and thus allows for reduced laser power to the recording layer while still achieving a high thermal gradient at the recording layer.
    Type: Application
    Filed: February 9, 2021
    Publication date: May 5, 2022
    Inventors: Hoan Cong Ho, Paul Christopher Dorsey, Tomoko Seki
  • Patent number: 10276199
    Abstract: High thermal gradient heatsinks for heat assisted magnetic recording media are provided. One example magnetic recording medium for heat assisted magnetic recording includes a substrate, a first seed layer on the substrate, a heatsink layer on the first seed layer and including Ru having a crystal texture of (11.0), a second seed layer on the heatsink layer, and a magnetic recording layer on the second seed layer. Methods for manufacturing such magnetic recording media are also disclosed.
    Type: Grant
    Filed: June 29, 2016
    Date of Patent: April 30, 2019
    Assignee: WD MEDIA, LLC
    Inventors: Hoan Cong Ho, Tomoko Seki, Paul C. Dorsey, Antony Ajan
  • Patent number: 9824710
    Abstract: A heat-assisted magnetic recording (HAMR) medium has a multilayered or laminated heat-sink structure. The laminated heat-sink structure includes a first heat-sink layer and a RuAl—X thermal barrier layer between the medium substrate and the first heat-sink layer. The laminated heat-sink structure may include a second heat-sink layer may between the substrate and the RuAl—X thermal barrier layer. In the RuAl—X thermal barrier layer, X is selected from C and one or more oxides of Si, Ti, W, Zr and Hf. The HAMR medium with the laminated heat-sink structure reduces the amount of required laser current as compared to a similar HAMR medium with a conventional single heat-sink layer of the same thickness, while also slightly improving magnetic properties and recording performance.
    Type: Grant
    Filed: May 1, 2017
    Date of Patent: November 21, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hua Yuan, Shahid Ali Pirzada, Hoan Cong Ho, Paul Christopher Dorsey, B. Ramamurthy Acharya
  • Patent number: 9406329
    Abstract: Segregants for magnetic recording layers and materials for intermediate layers underlying the magnetic recording layers are provided for improved heat assisted magnetic recording (HAMR) media. One such HAMR medium includes a substrate, a heat sink layer on the substrate, an underlayer on the heat sink layer, an intermediate layer of TiON, VON, CrON, TiOC, VOC, TiONC, and/or combinations thereof, on the underlayer, and a magnetic recording layer of FePt on the intermediate layer. The magnetic recording layer further includes three sublayers, each having a different segregant. The segregant of the first magnetic recording sublayer on the intermediate layer includes AgBN, AgCN, AgBNC, AgB2O3, AgMoO3, AgV2O5, B2O3, MoO3, V2O5, and/or combinations thereof.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: August 2, 2016
    Assignee: WD Media, LLC
    Inventors: Hoan Cong Ho, Hua Yuan, Tomoko Seki, Antony Ajan, Paul C. Dorsey