Wd Media, LLC

Western Digital Technologies, Inc.

Hot Socket, LLC

Hot Sockett, LLC

Western Digital Media, LLC

Paul Christopher Dorsey

Hoan Cong Ho

David Treves

Tomoko Seki

Pierre-Olivier Jubert

Hua Yuan

Antony Ajan

Andrew M Homola

Thomas Anthony O'Dell

Chunbin Zhang

B Ramamurthy Acharya

Shahid Ali Pirzada

Rui Zhang

Calvin Tue Chiu Siu

Yi Heng Chen

Gerardo Bertero

Alan Kalitsov

Allen J Bourez

Alexander S Chernyshov

David E Wachenschwanz

Kumar Srinivasan

Bogdan Florin Valcu

Zhaoqiang Bai

Tatsuru Tanaka

Fenghua Zong

Yew Ming Chiong

Wen Jiang

Xiaofeng Yao

Chin Yim Poon

Oleg Mryasov

Yang Yun

Asif Bashir

Various apparatuses, systems, methods, and media are disclosed for heat-assisted magnetic recording (HAMR) that includes a HAMR medium with a seed-thermal barrier structure. The seed-thermal barrier structure is positioned between a heat sink layer and a magnetic recording layer. In some examples, the seed-thermal barrier structure has a first layer including MgOTiO (MTO), a second layer including TiN on the first layer, a third layer on the second layer, and a fourth layer including MTO on the third layer. The third layer, in some examples, includes at least one of: RuAl, Pt, PtZr, PtTa, Rh, FePt, CrMo, or Cr.

Media underlayer structure for heat-assisted magnetic recording and media fabrication methods therefor

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 MgO—TiO (MTO) underlayer, where the MTO underlayer is formed using pulsed DC sputtering and has less than 50 mol % of TiO. By providing an MTO layer with less than 50 mol % of TIO, smaller grain sizes may be achieved in the magnetic recording layer, providing for higher areal densities. In some embodiments, a second MTO underlayer is provided, which is formed using non-pulsed DC sputtering and has 50 mol % of TiO. That is, a dual-layer MTO underlayer may be provided with, e.g., an MgO-30TiO layer atop an MgO-50TiO layer.

Magnetic recording medium with magnesium-titanium oxide (MTO) layer formed using pulsed direct current sputter deposition

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.

Media structure with selected segregants configured to improve heat-assisted magnetic recording

Various apparatuses, systems, methods, and media are disclosed for heat-assisted magnetic recording (HAMR) that, in some examples, provide a HAMR medium with two soft underlayers (SULs) on opposing sides of a single heatsink layer. For example, a magnetic recording medium is provided that includes a lower SUL on a substrate. The lower SUL is configured and positioned within the medium to provide a first return path for magnetic flux from a magnetic recording head during a write operation. The medium also includes a heatsink layer on the lower SUL and an upper SUL on the heatsink layer. The upper SUL is configured and positioned within the medium to provide a second return path for magnetic flux from the magnetic recording head. A magnetic recording layer is provided on the upper SUL to store information during the write operation. Additional layers or films may be provided as well.

Magnetic recording medium with multiple soft underlayers and magnetic recording apparatus for use therewith

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.

Magnetic recording medium with underlayer configured to reduce diffusion of titanium into a magnetic recording layer

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.

Heat-assisted magnetic recording (HAMR) medium with optical-coupling multilayer between the recording layer and heat-sink layer

System and method for controlling an irrigation system using feedback from flow meters installed in an irrigation system are described. The system and method allows for automatic detection of the number of flow meters and their relation to controls valves attached to an irrigation system and for precise and reliable fluid flow measurements. Typical water flows for the system are learned and then compared to current water flows to detect water leaks (i.e., high water flow), malfunctioning control valves and/or low water flow and subsequently trigger electronic alerts to the user when system malfunctions are detected.

System and method for fluid flow measurement and control

Aspects of the present disclosure provide a heat assisted magnetic recording HAMR media structure and methods for reducing the Curie temperature distribution to improve the signal-to-noise characteristics of HAMR media. A magnetic recording medium includes a substrate, a heat sink layer on the substrate, and a magnetic recording layer on the heat sink layer. The magnetic recording layer includes a plurality of magnetic recording grains configured for recording and comprising a first magnetic alloy. The magnetic recording layer further includes a plurality of segregants disposed to isolate the plurality of magnetic recording grains and comprising a second magnetic alloy. A Curie temperature of the second magnetic alloy is higher than a Curie temperature of the first magnetic alloy.

Heat assisted magnetic recording media with amorphous magnetic grain boundary material

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.

Heat-assisted magnetic recording (HAMR) medium with multilayered underlayer for the recording layer

A circuit that can be used to add a flow meter to an existing set of wires that connects a controller to an electric valve. The circuit does not require the need to run additional wiring from the controller to the valve and flow meter. The circuit creates pulses of current with a rate that is proportional to the flow, which are then transmitted to a receiver and converted to a flow measurement output to the user by a controller.

Electronic circuit for fluid flow measurement and control

A heat-assisted magnetic recording (HAMR) medium has a non-magnetic multilayered overcoat on the recording layer. The overcoat includes a heat-dissipation layer, a diamond-like carbon (DLC) layer on and in contact with the heat-dissipation layer, and an optional interface layer between and in contact with the recording layer and the heat-dissipation layer. The heat-dissipation layer is a material with relatively high in-plane thermal conductivity, substantially higher than the in-plane thermal conductivity of both the DLC layer and the recording layer. The heat-dissipation layer laterally spreads the heat generated in the DLC layer by absorption of light from the near-field transducer to thereby reduce the temperature of the DLC layer. The optional interface layer is a material with relatively low thermal conductivity and increases the thermal resistance between the recording layer and the heat-dissipation layer.

Heat-assisted magnetic recording (HAMR) medium with multilayered overcoat

System and method for controlling an irrigation system using feedback from flow meters installed in an irrigation system are described. The systems and method allows for automatic detection of the number of flow meters and their relation to controls valves attached to an irrigation system and for precise and reliable fluid flow measurements. Typical water flows for the system are learned and then compared to current water flows to detect water leaks (i.e., high water flow), malfunctioning control valves and/or low water flow and subsequently trigger electronic alerts to the user when system malfunctions are detected.

A heat-assisted magnetic recording (HAMR) medium has a heat-sink layer, a chemically-ordered FePt (or CoPt) alloy magnetic layer and a MgNiO intermediate layer between the heat-sink layer and the magnetic layer. The intermediate layer is a solid substitution crystalline alloy of the form (MgNi)O, where y is less than 10 and greater than or equal to 0.5. The magnetic layer may be formed directly on the MgNiO intermediate layer, in which case the MgNiO intermediate layer functions as both a seed layer and a thermal barrier layer. The HAMR medium may also include an optional layer of crystalline 'pure' MgO directly below or directly above the MgNiO intermediate layer. If the MgO layer is located directly above the MgNiO intermediate layer then the MgNiO intermediate layer functions primarily as a thermal barrier layer. The HAMR medium with the MgNiO intermediate layer provides a substantial improvement in corrosion resistance.

Heat-assisted magnetic recording (HAMR) medium with improved corrosion resistance

Magnetic media having dual phase MgO-X seed layers with both MgO grains and segregants are provided. One such magnetic medium includes a substrate, a heatsink layer on the substrate, a dual phase seed layer on the heatsink layer, where the dual phase seed layer comprises MgO and a segregant, where a concentration of the MgO is greater than 50 percent by volume in the dual phase seed layer, and a magnetic recording layer including FePt on the dual phase seed layer.

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Los Altos, CA, United States of America

Paul Christopher Dorsey