Patents by Inventor Tuqiang Li
Tuqiang Li 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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Patent number: 10923147Abstract: Magnetic media including a magnetic recording layer structure of at least six magnetic recording sublayers and at least six non-magnetic exchange control sublayers in an alternating pattern are provided. The magnetic recording layer structure includes a gradient of platinum content across the magnetic recording sublayers such that a top magnetic recording sublayer has a lowest platinum content and a bottom magnetic recording sublayer has a highest platinum content. In one such case, the magnetic media includes a substrate and the magnetic recording layer structure on the substrate. In another case, a method of fabricating such magnetic media is provided.Type: GrantFiled: April 20, 2018Date of Patent: February 16, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Kai Tang, Arien Michael Ghaderi, Tuqiang Li, Chi Ho Lo
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Patent number: 10783915Abstract: A method and system provide a magnetic recording media usable in a magnetic storage device. The magnetic recording media includes a substrate, at least one intermediate layer and a magnetic recording stack for storing magnetic data. The intermediate layer(s) include a majority phase having a first diffusion constant and a secondary phase having a second diffusion constant greater than the first diffusion constant. The magnetic recording stack residing on the intermediate layer such that the at least one intermediate layer is between the substrate and the magnetic recording stack.Type: GrantFiled: October 26, 2017Date of Patent: September 22, 2020Assignee: Western Digital Technologies, Inc.Inventors: Kumar Srinivasan, Tuqiang Li, Mrugesh Desai
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Publication number: 20190325905Abstract: Magnetic media including a magnetic recording layer structure of at least six magnetic recording sublayers and at least six non-magnetic exchange control sublayers in an alternating pattern are provided. The magnetic recording layer structure includes a gradient of platinum content across the magnetic recording sublayers such that a top magnetic recording sublayer has a lowest platinum content and a bottom magnetic recording sublayer has a highest platinum content. In one such case, the magnetic media includes a substrate and the magnetic recording layer structure on the substrate. In another case, a method of fabricating such magnetic media is provided.Type: ApplicationFiled: April 20, 2018Publication date: October 24, 2019Inventors: Kai Tang, Arien Michael Ghaderi, Tuqiang Li, Chi Ho Lo
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Publication number: 20180047420Abstract: A method and system provide a magnetic recording media usable in a magnetic storage device. The magnetic recording media includes a substrate, at least one intermediate layer and a magnetic recording stack for storing magnetic data. The intermediate layer(s) include a majority phase having a first diffusion constant and a secondary phase having a second diffusion constant greater than the first diffusion constant. The magnetic recording stack residing on the intermediate layer such that the at least one intermediate layer is between the substrate and the magnetic recording stack.Type: ApplicationFiled: October 26, 2017Publication date: February 15, 2018Inventors: Kumar Srinivasan, Tuqiang Li, Mrugesh Desai
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Patent number: 9818442Abstract: A method and system provide a magnetic recording media usable in a magnetic storage device. The magnetic recording media includes a substrate, at least one intermediate layer and a magnetic recording stack for storing magnetic data. The intermediate layer(s) include a majority phase having a first diffusion constant and a secondary phase having a second diffusion constant greater than the first diffusion constant. The magnetic recording stack residing on the intermediate layer such that the at least one intermediate layer is between the substrate and the magnetic recording stack.Type: GrantFiled: December 1, 2014Date of Patent: November 14, 2017Assignee: WD MEDIA, LLCInventors: Kumar Srinivasan, Tuqiang Li, Mrugesh Desai
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Patent number: 9685184Abstract: A recording medium having improved signal-to-noise ratio (SNR) capabilities includes a NiFeX-based magnetic seed layer over a soft magnetic underlayer, where X comprises an element that is soluble in and has a higher melting point than Ni. X may be selected from a group of elements, including ruthenium (Ru), which may facilitate growth of smaller grains and distributions in the corresponding magnetic recording layer(s).Type: GrantFiled: September 25, 2014Date of Patent: June 20, 2017Assignee: WD Media, LLCInventors: Kumar Srinivasan, Tuqiang Li, Mrugesh Desai
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Publication number: 20160155460Abstract: A method and system provide a magnetic recording media usable in a magnetic storage device. The magnetic recording media includes a substrate, at least one intermediate layer and a magnetic recording stack for storing magnetic data. The intermediate layer(s) include a majority phase having a first diffusion constant and a secondary phase having a second diffusion constant greater than the first diffusion constant. The magnetic recording stack residing on the intermediate layer such that the at least one intermediate layer is between the substrate and the magnetic recording stack.Type: ApplicationFiled: December 1, 2014Publication date: June 2, 2016Inventors: KUMAR SRINIVASAN, TUQIANG LI, MRUGESH DESAI
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Patent number: 8956741Abstract: Media may be produced with narrow c-axis dispersion while having small grain size and high grain density. A dual seed layer design and a substrate bias voltage may be applied during deposition of the seed layer are used in the media. In some embodiments, the first seed layer is an amorphous material because of a high content of elements with large atomic sizes. Application of the substrate bias during deposition of the second seed layer may reduce the grain size and may narrow c-axis dispersion.Type: GrantFiled: June 30, 2011Date of Patent: February 17, 2015Assignee: WD Media, LLCInventors: Tuqiang Li, Donald C. Stafford, Sudhir S. Malhotra, Tsutomu T. Yamashita
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Patent number: 8895164Abstract: A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate. The SUL has a plurality of SUL layers including a type-A SUL layer, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb.Type: GrantFiled: June 9, 2009Date of Patent: November 25, 2014Assignee: Fuji Electric Co., Ltd.Inventors: Tuqiang Li, Shunji Takenoiri, Yuko Ueki
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Publication number: 20090305080Abstract: A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate. The SUL has a plurality of SUL layers including a type-A SUL layer, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb.Type: ApplicationFiled: June 9, 2009Publication date: December 10, 2009Applicant: Fuji Electric Device Technology Co., Ltd.Inventors: Tuqiang Li, Shunji Takenoiri, Yuko Ueki
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Publication number: 20080318085Abstract: A method of forming a carbon protective film is disclosed that improves electromagnetic conversion characteristics through reduction of the film thickness without any damage on a magnetic layer. Also disclosed is a magnetic recording medium that exhibits good electromagnetic conversion characteristics and corrosion resistance. The method of forming the carbon protective film uses a high frequency plasma CVD method on a disk including at least a magnetic film on a nonmagnetic substrate. A bias voltage in a range of ?200 V to zero V is applied at the beginning of discharge in a process of forming the carbon protective film, and a bias voltage in a range of ?500 V to ?200 V is applied at the end of discharge. Also disclosed is a magnetic recording medium having at least a magnetic film and a protective film on a nonmagnetic substrate, wherein the protective film is formed by the method of forming a protective film stated above according to the invention.Type: ApplicationFiled: June 11, 2008Publication date: December 25, 2008Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Tuqiang LI, Masaki MIYAZATO, Tsuyoshi ONITSUKA, Makoto ISOZAKI, Hajime KURIHARA
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Publication number: 20080261080Abstract: A magnetic recording medium includes as formed on a non-magnetic substrate, a seed layer, an underlayer of a bcc structure-having Cr alloy, an interlayer of an hcp structure-having Ru alloy, a lower recording layer of a Co—Cr—Pt—B base alloy, an upper recording layer having the same alloying base components as those of the lower recording layer, a larger B atom concentration and having a larger Co atom concentration to Cr atom concentration ratio, and a protective layer. The lower recording layer includes a first and a second lower recording layer. When the B atom concentration in the first lower recording layer is B1 and that of the second lower recording layer is B2, then B1<B2, and when the Co atom concentration to Cr atom concentration ratio in the first lower recording layer is (Co/Cr)1, and that of the second lower recording layer is (Co/Cr)2, then (Co/Cr)1<(Co/Cr)2.Type: ApplicationFiled: December 21, 2007Publication date: October 23, 2008Applicants: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD., TOHOKU UNIVERSITYInventors: Hirohisa OHYAMA, Tuqiang Li, Daiji Hasegawa, Shin Saito, Migaku Takahashi
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Publication number: 20080044688Abstract: A high-recording-density magnetic recording medium and a method of its manufacture can achieve a high OR with only a small reduction in Hcr. The magnetic recording medium has a nonmagnetic substrate and a first seed layer, a second seed layer, a first underlayer, a second underlayer, and a magnetic recording layer formed on the substrate in this order. The first seed layer can be a single layer or a plurality of layers made of at least one material selected from the group consisting of Ni—Ti alloys, Cr—Al alloys, Cr—Ta alloys, and Cr—Ti alloys. The second seed layer can be a single layer or a plurality of layers made of at least one material selected from the group consisting of Ni—W alloys, Ni—Ru—W alloys, and Co—W alloys. The first underlayer can be a single layer or a plurality of layers made of a Cr—Ru alloy. The second underlayer can be a single layer or a plurality of layers made of a Cr alloy comprising Cr and at least one element selected from the group consisting of Mo, B, Ti, and W.Type: ApplicationFiled: March 7, 2007Publication date: February 21, 2008Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Tuqiang Li, Manabu Shimosato, Toyoji Ataka, Hiromi Ono, Kenichiro Soma, Hiroyuki Uwazumi, Souta Matsuo