Differing Compositions In Plurality Of Magnetic Layers (e.g., Layer Compositions Having Differing Elemental Components, Different Proportions Of Elements, Etc.) Patents (Class 428/829)
  • Patent number: 8580410
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium 100 including a magnetic recording layer 122, the medium in which a particle diameter of crystal grains in the magnetic recording layer 122 of a two-layer structure is so designed as to improve an SNR while a high coercive force is maintained.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: November 12, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Takahiro Onoue
  • Patent number: 8582241
    Abstract: A method and system for providing a magnetic read transducer is described. The magnetic recording transducer includes a write pole, a nonmagnetic gap, a magnetic seed layer, a trailing shield and coil(s) that energize the write pole. The write pole is configured to write to a media. The nonmagnetic gap is between the write pole and the magnetic seed layer. The magnetic seed layer includes a high moment layer and a magnetic buffer layer. The high moment layer is between the nonmagnetic gap and the magnetic buffer layer. The high moment layer has a saturation magnetization greater than 2.3 T and a first corrosion potential. The magnetic buffer layer has a second corrosion potential less than the first corrosion potential. The magnetic seed layer is between the trailing shield and the nonmagnetic gap layer. The magnetic buffer layer is between the trailing shield and the high moment layer.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: November 12, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Chengtao R. Yu, Dehua Han, Ying Hong, Feng Liu, Bo Zhang, Tao Pan
  • Patent number: 8580409
    Abstract: Perpendicular magnetic recording (PMR) media and methods of fabricating PMR media are described. The PMR media includes, among other layers, an underlayer, a first onset layer on the underlayer, a second onset layer on the first onset layer, and a perpendicular magnetic recording layer on the second onset layer. The second onset layer has a magnetic moment which is higher than both a magnetic moment of the first onset layer and a magnetic moment of the perpendicular magnetic recording layer.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: November 12, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Xiaoping Bian, Jack Jyh-Kau Chang, Zhupei Shi
  • Patent number: 8557408
    Abstract: A recording medium having a substrate, a first soft magnetic underlayer, a second soft magnetic underlayer and a perpendicular magnetic recording layer without a spacer layer between the first and second soft magnetic underlayers is disclosed.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: October 15, 2013
    Assignee: Seagate Technology LLC
    Inventors: Qixu Chen, Charles Brucker, Chung-Hee Chang, Tom Nolan, Samuel Dacke Harkness, IV
  • Patent number: 8546000
    Abstract: A perpendicular magnetic disk that includes, a base 110, a granular magnetic layer 160, and a auxiliary recording layer 180 disposed as an upper layer of the granular magnetic layer 160. The granular magnetic layer 160 has a granular structure in which a grain boundary portion is formed by segregation of a non-magnetic substance containing an oxide as a main component around magnetic particles containing a CoCrPt alloy grown in a columnar shape as a main component. The auxiliary recording layer 180 contains a CoCrPtRu alloy as a main component and has a film thickness of 1.5 nm to 4.0 nm. With this structure, the auxiliary recording layer can be thinned while maintaining the function thereof to improve SNR.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: October 1, 2013
    Assignee: WD Media, LLC
    Inventor: Teiichiro Umezawa
  • Patent number: 8530065
    Abstract: A composite hard magnetic recording layer for a magnetic storage comprises a hard magnetic layer and a capping layer. The composite recording layer has a crystal structure where crystal grains include a portion within the magnetic layer and a portion within the capping layer.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: September 10, 2013
    Assignee: WD Media, LLC
    Inventors: Alexander Chernyshov, Hua Yuan, B. Ramamurthy Acharya
  • Patent number: 8529989
    Abstract: The present invention relates to a method for manufacturing a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic under layer, an orientation control layer, a magnetic recording layer constituted of two or more layers and a protective layer formed on the nonmagnetic substrate, the method including a step of forming a first magnetic recording layer having a granular structure constituted of ferromagnetic crystal grains and crystal grain boundaries made of a nonmagnetic oxide or nitride on the nonmagnetic substrate side, a step of forming a second magnetic recording layer constituted only of ferromagnetic crystal grains, a step of forming a surface unevenness control layer for decreasing surface unevenness of the first magnetic recording layer located between the first magnetic recording layer and the second magnetic recording layer, and a step of heating the nonmagnetic substrate so as to decrease a surface roughness Ra of the second magnetic recording layer
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: September 10, 2013
    Assignee: Showa Denko K.K.
    Inventors: Gohei Kurokawa, Yuzo Sasaki
  • Publication number: 20130209835
    Abstract: A method involves depositing a seed layer comprising at least A1 phase FePt. A main layer of A1 phase FePt is deposited over the seed layer. The main layer includes FePt of a different stoichiometry than the seed layer. The seed and main layers are annealed to convert the A1 phase FePt to L10 phase FePt. The annealing involves heating the substrate prior to depositing at least part of the A1 phase FePt of the main or seed layers.
    Type: Application
    Filed: March 15, 2013
    Publication date: August 15, 2013
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventor: SEAGATE TECHNOLOGY LLC
  • Publication number: 20130208578
    Abstract: Disclosed is a magnetic recording medium having a structure in which at least an underlayer, a first magnetic layer and a second magnetic layer are sequentially stacked on a substrate, wherein the first magnetic layer includes an alloy having an L1o structure as a main component, and wherein the second magnetic layer includes a non-crystalline alloy including Co as a main component and containing Zr of 6 to 16 atomic percent and at least one element of B and Ta.
    Type: Application
    Filed: February 11, 2013
    Publication date: August 15, 2013
    Applicant: SHOWA DENKO K.K.
    Inventor: SHOWA DENKO K.K.
  • Patent number: 8507114
    Abstract: A magnetic stack includes multiple granular layers, at least one of the multiple granular layers is a magnetic layer that includes exchange coupled magnetic grains separated by a segregant having Ms greater than 100 emu/cc. Each of the multiple granular layers have anisotropic thermal conductivity.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: August 13, 2013
    Assignee: Seagate Technology LLC
    Inventors: Yingguo Peng, Jan-Ulrich Thiele, Ganping Ju, Thomas Patrick Nolan, Yinfeng Ding, Alexander Qihong Wu
  • Patent number: 8507115
    Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a soft magnetic underlayer having an amorphous structure or a microcrystalline structure, a first seed layer comprised of a magnetic material having an fcc crystal structure including a CoFe alloy formed on a substrate side, and a second seed layer formed on the first seed layer, the second seed layer comprised of a nonmagnetic material having an fcc crystal structure including a NiW alloy. The medium also includes an intermediate layer comprised of Ru or an alloy thereof, a magnetic recording layer, and a protective layer, wherein the layers are sequentially stacked on a substrate in the foregoing order and the protective layer is closer to the substrate than the soft magnetic underlayer. Other embodiments of magnetic recording media, and methods of fabrication, are also described.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: August 13, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Reiko Arai, Niroyuki Nakagawa
  • Patent number: 8492010
    Abstract: A silicon/gold (Si/Au) bilayer seed structure is located in a film stack between an amorphous or crystalline lower layer and an upper layer with a well-defined crystalline structure. The seed structure includes a Si layer on the generally flat surface of the lower layer and a Au layer on the Si layer. The Si/Au interface initiates the growth of the Au layer with a face-centered-cubic (fcc) crystalline structure with the (111) plane oriented in-plane. The upper layer grown on the Au layer has a fcc or hexagonal-close-packed (hcp) crystalline structure. If the upper layer is a fcc material its [111] direction is oriented substantially perpendicular to the (111) plane of the Au layer and if the upper layer is a hcp material, its c-axis is oriented substantially perpendicular to the (111) plane of the Au layer.
    Type: Grant
    Filed: May 1, 2010
    Date of Patent: July 23, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Olav Hellwig, Dieter K. Weller
  • Patent number: 8492009
    Abstract: A method of fabricating a perpendicular magnetic recording disk is described. The method may include providing a magnetic recording layer disposed above a substrate with a plurality of intermediate layers disposed there between and electrochemically etching the magnetic recording layer.
    Type: Grant
    Filed: August 25, 2009
    Date of Patent: July 23, 2013
    Assignee: WD Media, Inc.
    Inventors: Andrew Homola, Chunbin Zhang, Paul C. Dorsey, David Treves
  • Publication number: 20130155542
    Abstract: In one embodiment, a perpendicular magnetic recording medium includes an oxide recording layer including an oxide and a non-oxide recording layer which does not contain an oxide positioned above the oxide recording layer. The oxide recording layer includes a region R1 where a grain boundary width in a direction parallel to a plane of formation of R1 increases therealong from a lowermost portion of the oxide recording layer toward a medium surface, a region R3 positioned above R1 wherein a grain boundary width increases therealong toward the medium surface, a region R2 where a grain boundary width of R2 decreases therealong from R1 to R3, with R2 being positioned between R1 and R3, and a region R4 where a grain boundary width of R4 decreases therealong from R3 toward the medium surface, with R4 being positioned above R3 and near an uppermost portion of the oxide recording layer.
    Type: Application
    Filed: December 14, 2011
    Publication date: June 20, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shun Tonooka, Kiwamu Tanahashi, Hiroyuki Nakagawa, Ichiro Tamai
  • Patent number: 8460805
    Abstract: An apparatus includes a first magnetic layer including a plurality of grains. The first magnetic layer has a first anisotropy value. The apparatus also includes a second magnetic layer including a plurality of grains. The second magnetic layer has a second anisotropy value that is different than the first anisotropy value. The apparatus also includes an exchange tuning layer including a plurality of grains and located between the first and second magnetic layers. The exchange tuning layer has stronger inter-granular exchange coupling than the first and second magnetic layers. The exchange tuning layer has an anisotropy value less than the first and second anisotropy values.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: June 11, 2013
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Yingguo Peng
  • Publication number: 20130143073
    Abstract: An apparatus having a recording layer of a magnetic material with a concentration of implanted ions that increases in relation to a thickness direction of the recording layer to provide the recording layer with a continuously varied perpendicular magnetic anisotropy constant.
    Type: Application
    Filed: January 28, 2013
    Publication date: June 6, 2013
    Applicant: SEAGATE TECHNOLOGY INTERNATIONAL
    Inventor: SEAGATE TECHNOLOGY INTERNATIONAL
  • Patent number: 8455118
    Abstract: An apparatus may include a composite soft underlayer and a perpendicular magnetic recording layer overlying the composite soft underlayer. The composite soft underlayer may include a growth template layer, a negative magnetic anisotropy layer overlying the growth template layer, and a magnetically soft layer overlying the negative magnetic anisotropy layer. In some embodiments, the negative magnetic anisotropy layer includes a plurality of grains, and substantially all the grains have negative magnetic anisotropy along an axis substantially perpendicular to a major plane of the composite soft underlayer. In some embodiments, the negative magnetic anisotropy layer includes a thickness of less than or equal to about 3 nm.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: June 4, 2013
    Assignee: Seagate Technology LLC
    Inventors: Kai-Chieh Chang, Li Tang, Shanghsien S. Rou, Connie Chunling Liu, Bogdan Florin Valcu, Wen Jiang, Tao Zhang
  • Patent number: 8455119
    Abstract: A magnetic disk includes a substrate, a soft magnetic underlayer disposed over the substrate, and a media layer disposed over the underlayer. The underlayer includes a plurality of magnetic layers each containing FeCoN having an atomic concentration of iron that is greater than an atomic concentration of cobalt, and has an atomic concentration of nitrogen that is less than the atomic concentration of cobalt. The atomic concentration of nitrogen is less than eight percent. The underlayer includes a plurality of nonmagnetic layers that are interleaved with the magnetic layers. Each of the nonmagnetic layers has a thickness that is less than one-tenth that of an adjoining layer of the magnetic layers. The media layer contains a magnetically hard material having an easy axis of magnetization oriented substantially perpendicular to both the media layer and the underlayer.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: June 4, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Hai Jiang, Kyusik Sin, Yingjian Chen
  • Patent number: 8440332
    Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium that reduces the noise of granular recording layers, obtains sufficient overwrite characteristic that suppresses an increase in the magnetic cluster size, and allows high-density recording. According to one embodiment, a perpendicular magnetic recording medium comprising substrate having thereon at least soft magnetic layer, nonmagnetic intermediate layer, a perpendicular recording layer and protective layer formed in that order. The perpendicular recording layer consists of three or more layers of first recording layer, a second recording layer, and a third recording layer from the side nearer to the substrate. The first recording layer and the second recording layer have a granular structure comprising a grain boundary of an oxide surrounding ferromagnetic crystal grains containing Co and Pt, and the third recording layer has a non-granular structure mainly comprising Co and not containing an oxide.
    Type: Grant
    Filed: April 8, 2009
    Date of Patent: May 14, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Ichiro Tamai, Kiwamu Tanahashi
  • Patent number: 8431257
    Abstract: A perpendicular magnetic recording medium is used for information recording of a perpendicular magnetic recording type. The perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, an underlayer, and a magnetic layer having a multilayered structure including a plurality of magnetic layers. The soft magnetic layer, the underlayer, and the magnetic layer are formed on the substrate. At least one of the magnetic layers includes CoPt magnetic grains containing oxide. The oxide includes at least one material selected from the group consisting of SiO2, TiO2, Cr2O3, Ta2O5, WO3, CoO, and Co3O4.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: April 30, 2013
    Assignee: WD Media (Singapore) PTE. Ltd.
    Inventors: Kong Kim, Hi Shin, Tomoko Seki, Satoshi Ishii
  • Patent number: 8404368
    Abstract: In some embodiments, an article comprising a first magnetic recording layer, the first magnetic recording layer including a granular layer having a first magnetic anisotropy and a multi-layer stack adjacent the granular layer, the multi-layer stack comprising one or more substantially magnetic film layers alternating with one or more polarization conductor layers, wherein the multi-layer stack has a second magnetic anisotropy that is greater than the first magnetic anisotropy.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: March 26, 2013
    Assignee: Seagate Technology LLC
    Inventors: Zhong Wu, Shanghsien Rou
  • Patent number: 8383254
    Abstract: An apparatus includes a substrate, a magnetically soft underlayer on the substrate, and a plurality of generally cubic FePt nanoparticles on the magnetically soft underlayer, wherein the nanoparticles have a magnetization in a direction substantially normal to a surface of the magnetically soft underlayer. The FePt nanoparticles can have magnetically easy axes perpendicular to the surface of the soft underlayer.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: February 26, 2013
    Assignee: Seagate Technology LLC
    Inventors: Nisha Shukla, Timothy John Klemmer, Dieter Klaus Weller, Chao Liu
  • Patent number: 8383253
    Abstract: Embodiments of the present invention produce discrete track media and bit patterned media having both excellent read/write performance and reliability. According to one embodiment, the medium comprises a magnetic layers formed by at least two ferromagnetic alloy layers with different compositions on a substrate. The ferromagnetic alloy layer located closest to the medium surface has more concentrated parts and less concentrated parts of nonmagnetic element in the in-plane direction. The more concentrated parts of the nonmagnetic element contain more nonmagnetic elements than the other parts except for an intermediate layer in the magnetic recording layer. The more concentrated parts and the less concentrated parts of the nonmagnetic element in the ferromagnetic alloy layer located closest to the medium surface are formed substantially concentric. The more concentrated parts of the nonmagnetic element is formed by being doped with ions of nonmagnetic element.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: February 26, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Tatsuya Hinoue, Hiroshi Kanai, Toshinori Ono, Hiroyuki Suzuki, Hiroshi Inaba
  • Patent number: 8367229
    Abstract: The present invention relates to a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic layer (SUL), an alignment control layer, a magnetic recording layer and a protective layer formed on the nonmagnetic substrate, wherein the magnetic recording layer is constituted of two or more layers and includes a first magnetic recording layer and a second magnetic recording layer from the nonmagnetic substrate side and, regarding magnetocrystalline anisotropic energy Ku of each magnetic recording layer, the first magnetic recording layer has 4×106 erg/cc or higher and the second magnetic recording layer has 2×106 erg/cc or lower, wherein the first magnetic recording layer is constituted of CoCrPtRu magnetic alloy crystal grains and grain boundaries made of an oxide and the area of grain boundaries is 30% or more based on the entire area in a planar TEM observation of the first magnetic recording layer.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: February 5, 2013
    Assignee: Showa Denko K.K.
    Inventor: Yuzo Sasaki
  • Patent number: 8361641
    Abstract: A perpendicular magnetic recording medium and a method of manufacturing the same are provided. The perpendicular magnetic recording medium comprises a recording layer including a plurality of regions formed in the depth direction of the recording layer and a magnetic anisotropy constant of a region relatively deeper than another region, among the plurality of regions, is greater than that of the another region. The method of manufacturing a perpendicular magnetic recording medium includes: forming a recording layer having perpendicular magnetic anisotropy; and irradiating the recording layer with ions.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: January 29, 2013
    Assignee: Seagate Technology LLC
    Inventors: Seong-yong Yoon, Chee-kheng Lim, Hoo-san Lee, Hoon-sang Oh, Sok-hyun Kong
  • Patent number: 8361640
    Abstract: Embodiments of the present invention provide recording area separated magnetic recording media (DTMs, BPMs) allowing magnetic heads to fly lower. According to one embodiment, the recording area separated magnetic recording media are configured so that magnetic recording layers have parts with the relatively higher element ratio of a ferromagnetic material, and parts with the lower element ratio of the ferromagnetic material, occurring periodically in the in-plane direction, and the average height from the substrate surface of the parts with the relatively higher element ratio of a ferromagnetic material is higher than the average height from the substrate surface of the parts with the lower element ratio of the ferromagnetic material.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: January 29, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Toshinori Ono, Hiroshi Kanai, Tatsuysa Hinoue, Hiroyuki Suzuki, Hiroshi Inaba
  • Patent number: 8355223
    Abstract: The present invention provides a magnetic recording medium that has sufficient recording/reproducing characteristics and good write characteristics and can correspond to high recording density, and a method of manufacturing the same. A magnetic recording medium 1 includes a plurality of magnetic recording patterns 2 that is magnetically separated from each other. Each of the magnetic recording patterns 2 includes a low-coercivity region 2a and a high-coercivity region 2b having a coercivity higher than the low-coercivity region, and the high-coercivity region 2b is arranged at the center of the low-coercivity region 2a in a plan view.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: January 15, 2013
    Assignee: Showa Denko K.K.
    Inventors: Shinichi Ishibashi, Akira Yamane
  • Patent number: 8338007
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
  • Patent number: 8338005
    Abstract: A media for perpendicular recording and a method of creating the media is provided. The media includes a hard recording layer and a soft underlayer (SUL). The SUL is composed of at least two anti-ferromagnetically coupled (AFC) sub-underlayers. The sub-underlayers respond to a magnetic field established during dynamic reversal with respective magnetic fields. The sub-underlayers are formed and disposed to differ in one or more magnetic moment, anisotropy, and thickness, so that their respective magnetic fields constructively interfere in one or more points in the hard recording layer, thereby reducing a total SUL magnetic field response to the dynamic reversal field approximately to zero at one or more points in the hard recording layer, which reduces side track erasure.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: December 25, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Qixu Chen, Chung-Hee Chang, Thomas Patrick Nolan
  • Patent number: 8329321
    Abstract: A perpendicular magnetic recording medium is disclosed that achieves improved recordability without deteriorating thermal stability by reducing the switching field. A perpendicular magnetic recording medium of the invention has a first magnetic recording layer and a second magnetic recording layer between with is interposed a coupling layer that ferromagnetically couples the two layers. The first and second magnetic recording layers satisfy an inequality Ku1T1>Ku2T2 in the case where Hk1 >Hk2 and an inequality Ku1T1<Ku2T2 in the case where Hk1<Hk2, where Hk1 and Hk2 are anisotropy magnetic fields, Ku1 and Ku2 are uniaxial anisotropy constants, and T1 and T2 are thicknesses of the first magnetic recording layer and the second recording layer, respectively. An exchange coupling energy between the magnetic recording layers is preferably at least 5×10?3 erg/cm2.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: December 11, 2012
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shunji Takenoiri, Yasushi Sakai
  • Publication number: 20120300600
    Abstract: A thermally assisted magnetic recording medium having a structure in which a first magnetic layer 106 and a second magnetic layer 107 are formed on a substrate 101 in this order, wherein the first magnetic layer 106 has a granular structure containing a FePt alloy having a L10 structure, a CoPt alloy having a L10 crystal lattice structure or a CoPt alloy having a L11 crystal lattice structure, and at least one material for causing grain boundary segregation selected from the group consisting of SiO2, TiO2, Cr2O3, Al2O3, Ta2O5, ZrO2, Y2O3, CeO2, MnO, TiO, ZnO, and MgO, and the content of the material for causing grain boundary segregation in the first magnetic layer 106 is decreased from the substrate side to the second magnetic layer 107 side.
    Type: Application
    Filed: January 24, 2011
    Publication date: November 29, 2012
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya Kanbe, Atsushi Hashimoto, Takayuki Fukushima
  • Patent number: 8313848
    Abstract: A perpendicular magnetic recording medium having a substrate, a Cr-doped Fe-alloy-containing underlayer containing about 8 to 18 at % Cr and a perpendicular recording magnetic layer, and a process for improving corrosion resistance of the recording medium and for manufacturing the recording medium are disclosed.
    Type: Grant
    Filed: August 15, 2011
    Date of Patent: November 20, 2012
    Assignee: Seagate Technology LLC
    Inventors: Raj Nagappan Thangaraj, Mariana Rodica Munteanu, Erol Girt, Michael J. Stirniman, Thomas Patrick Nolan
  • Patent number: 8309239
    Abstract: A vertical magnetic recording disc (100) includes a base (10), a magnetic recording layer (22), and a medium protection layer (26). The magnetic recording layer (22) is a ferromagnetic layer having a granular structure where a granular portion is formed. The medium protection layer (26) contains nitrogen (N) atoms and carbon (C) atoms with a number ratio (N/C) in a range from 0.050 to 0.150. In a Raman spectrum obtained by exciting the medium protection layer (26) by argon ion laser light of wavelength 514.5 nm, from which a fluorescence is removed, the peak ratio Dh/Gh is in a range from 0.70 to 0.95, when a D peak Dh appearing in the vicinity of 1350 cm?1 is separated from G peak Gh appearing in the vicinity of 1520 cm?1 by the Gauss function.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: November 13, 2012
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Teiichiro Umezawa, Masafumi Ishiyama, Kenji Ayama, Tokichiro Sato
  • Patent number: 8309238
    Abstract: The present invention has its object to offer magnetic recording medium and magnetic recording and reproducing device that can record and reproduce high density data by optimizing the soft magnetic layer material forming the soft magnetic underlayer and the under layer material. In the present invention, the perpendicular magnetic recording medium A has at least the soft magnetic underlayer a, the under layer 5, the intermediate layer 6 and the perpendicular magnetic recording layer on the non-magnetic substrate 1. The soft magnetic layers 2, 4 that form the soft magnetic underlayer a, has an amorphous structure and is made of CoAl alloy or CoFeAl alloy having saturation magnetic flux density Bs greater than 1.1 T.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: November 13, 2012
    Assignee: Showa Denko K.K.
    Inventor: Kenji Shimizu
  • Patent number: 8279555
    Abstract: A magnetic recording medium and a method of manufacturing the magnetic recording medium are provided. In order to increase the recording density of the magnetic recording medium, the magnetic recording medium is configured to multiple magnetic layers by consecutively forming a first magnetic layer having a thin film shape and a second magnetic layer comprising patterned magnetic bits. The first magnetic layer has a magnetic anisotropic coefficient greater than that of the second magnetic layer.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: October 2, 2012
    Assignee: Seagate Technology International
    Inventors: Myung-bok Lee, Jin-seung Sohn, Hoo-san Lee
  • Patent number: 8263190
    Abstract: The present invention aims to provide a method of producing a magnetic recording medium which is a method of producing a magnetic recording medium having a magnetically-separated magnetic recording pattern, the method including: forming a magnetic layer on a non-magnetic substrate; then exposing a surface of the magnetic layer partially to reactive plasma, or a reactive ion generated in the plasma to amorphize the portion of the magnetic layer.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: September 11, 2012
    Assignee: Showa Denko K.K.
    Inventors: Masato Fukushima, Akira Sakawaki, Yasumasa Sasaki
  • Publication number: 20120225325
    Abstract: Surface flatness of magnetic recording medium to which a magnetic recording layer made of L10 FePt magnetic alloy thin film, with distance between a magnetic head and a magnetic recording medium sufficiently reduced. The magnetic recording layer includes: magnetic layers containing a magnetic alloy including Fe and Pt as principal materials; and one non-magnetic material selected from carbon, oxide and nitride. The first magnetic layer disposed closer to a substrate has a granular structure in which magnetic alloy grains including FePt alloy as the principal material are separated from grain boundaries including the non-magnetic material as the principal material. The second magnetic layer disposed closer to the surface than the first magnetic layer is fabricated so as to have a homogeneous structure in which an FePt alloy and the non-magnetic material are mixed in a state finer than diameters of the FePt magnetic alloy grains in the first magnetic layer.
    Type: Application
    Filed: February 13, 2012
    Publication date: September 6, 2012
    Inventors: HIROAKI NEMOTO, Ikuko TAKEKUMA, Kimio NAKAMURA, Junichi SAYAMA
  • Patent number: 8257845
    Abstract: Embodiments of the present invention help to produce discrete track media and bit patterned media having both excellent recording and reproducing performance and reliability. According to one embodiment, a manufacturing method forms a nonmagnetic layer mainly composed of the same element as a nonmagnetic element contained in magnetic recording layers and on the magnetic recording layers and a mask layer having apertures for forming more concentrated parts of the nonmagnetic element in the magnetic recording layers on the nonmagnetic layer. The method implants ions of the nonmagnetic element through the nonmagnetic layer masked by the mask layer to form the more concentrated parts of the nonmagnetic element in the magnetic recording layer.
    Type: Grant
    Filed: February 10, 2009
    Date of Patent: September 4, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tatsuya Hinoue, Hiroshi Kanai, Toshinori Ono, Hiroyuki Suzuki, Hiroshi Inaba
  • Publication number: 20120219827
    Abstract: A stack including a crystallographic orientation interlayer, a magnetic zero layer disposed on the interlayer, and a magnetic recording layer disposed on the magnetic zero layer is disclosed. The magnetic zero layer is non-magnetic or has a saturation magnetic flux density (Bs) less than about 100 emu/cc. The magnetic zero layer and the magnetic layer include grains surrounded by a non-magnetic segregant. The magnetic zero layer provides a coherent interface between the interlayer and the magnetic layer with a lattice mismatch less than about 4%.
    Type: Application
    Filed: February 28, 2011
    Publication date: August 30, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Jai-Young Kim, Thomas P. Nolan, Kyongha Kang, Shoutao Wang, Vincent D. Nguyen, Abebe Hailu, Charles C. Chen
  • Patent number: 8241766
    Abstract: An apparatus includes a plurality of bilayer structures positioned adjacent to each other, each of the bilayer structures including a first layer of magnetic material having a first Curie temperature and a second layer of magnetic material positioned adjacent to the first layer, wherein the second layer has a second Curie temperature that is lower than the first Curie temperature, and magnetic grains of the first layer are unstable when the second layer of magnetic material is heated above the second Curie temperature. The recording temperature is reduced due to the smaller switching volume achieved by using vertically decoupled laminations at elevated temperatures.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: August 14, 2012
    Assignee: Seagate Technology LLC
    Inventors: Bin Lu, Ganping Ju
  • Patent number: 8228636
    Abstract: An apparatus, system and method for magnetic recording are disclosed. In at least one embodiment, the apparatus includes a first portion of a first magnetic medium having a first cross-sectional area, and a second portion of a second magnetic medium having a second cross-sectional area. The first and second portions are joined by way of a junction that allows for at least some ferromagnetic coupling therebetween. Additionally, the first and second cross-sectional areas are of differing extent in a first dimension so that a first ledge portion of one of the first and second portions extends past a first edge of the other of the first and second portions.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: July 24, 2012
    Assignee: The Regents of the University of California
    Inventors: Vitaliy Lomakin, Boris Livshitz, Richard Choi, Shaojing Li, Akihiro Inomata
  • Patent number: 8202636
    Abstract: A method is described for improving recording performance of a perpendicular media. The method includes controlling the anisotropy levels in different sublayers of the magnetic recording layers of the perpendicular media. Further, the different sublayers thicknesses can be altered to match the media to a particular head.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: June 19, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Gunn Choe, Yoshihiro Ikeda, Mohammad T. Mirzamaani, Kai Tang, Jinliu Wang
  • Publication number: 20120141834
    Abstract: Aspects include recording media with enhanced areal density through reduction of head media spacing, head keeper spacing, or head to soft underlayer spacing. Such aspects comprise replacing currently non-magnetic components of devices, such as interlayers and overcoats with components and compositions comprising magnetic materials. Other aspects relate to magnetic seed layers deposited within a recording medium. Preferably, these aspects, embodied as methods, systems and/or components thereof reduce effective magnetic spacing without sacrificing physical spacing.
    Type: Application
    Filed: February 13, 2012
    Publication date: June 7, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Bin Lu, Bogdan Florin Valcu, Xiaoding Ma
  • Patent number: 8168309
    Abstract: Perpendicular recording media with sublayers of dual oxide dopant magnetic materials are disclosed. The magnetic layer may comprise multiple sublayers of magnetic materials. In each sublayer, dual oxide dopants are incorporated. The compositions of the sublayers can be the same or different depending on the application. The magnetic layer may be deposited using a target comprising a mixture of CoPtCrB and dual oxides as dopants. The layer deposited with such targets can be the entire magnetic layer or a sublayer.
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Gunn Choe, Mohammad T. Mirzamaani, Kai Tang, Jinliu Wang
  • Patent number: 8168310
    Abstract: A magnetic storage medium according to one embodiment includes a substrate; a first oxide magnetic layer formed above the substrate; a second oxide magnetic layer formed above the first oxide magnetic layer; an exchange coupling layer formed above the second oxide magnetic layer, the exchange coupling layer comprising an oxide; and a magnetic cap layer formed above the exchange coupling layer. A method according to one embodiment includes forming a high Ku first oxide magnetic layer above a substrate by sputtering; forming a low Ku second oxide magnetic layer above the first oxide magnetic layer by sputtering; forming an exchange coupling layer of CoCrPt-oxide above the second oxide magnetic layer; and forming a magnetic cap layer above the exchange coupling layer. Additional systems and methods are also presented.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Xiaoping Bian, Jack Jyh-Kau Chang, Qing Dai, Hoa V. Do, Yoshihiro Ikeda, Kentaro Takano, Chu S. Tran
  • Publication number: 20120052330
    Abstract: A perpendicular magnetic recording medium having sufficient perpendicular uniaxial magnetic anisotropy energy and a crystal grain size for realizing an areal recording density of one terabit or more per one square centimeter, and excellent in mass productivity, and a manufacturing method of the same are provided. On a substrate, a substrate-temperature control layer, an underlayer and a magnetic recording layer are sequentially formed. The magnetic recording layer is formed by repeating a magnetic layer stacking step N times (N?2), which includes a first step of heating the substrate in a heat process chamber, and a second step of depositing, in a deposition process chamber, the magnetic recording layer constituted of an alloy mainly composed of FePt to which at least one kind of non-magnetic material selected from a group constituted of C and an Si oxide is added.
    Type: Application
    Filed: August 22, 2011
    Publication date: March 1, 2012
    Applicant: HITACHI, LTD.
    Inventors: Ikuko TAKEKUMA, Kimio NAKAMURA, Junichi SAYAMA, Hiroaki NEMOTO
  • Publication number: 20120044595
    Abstract: In one embodiment, a perpendicular magnetic recording medium (PMRM) includes a first interlayer comprising Ru or a Ru alloy, a second interlayer above the first interlayer comprising Ru or a Ru alloy, and a third interlayer formed between the first interlayer and the second interlayer that reduces an average cluster size of the second interlayer. In another embodiment, a PMRM includes a first interlayer comprising Ru or a Ru alloy, a second interlayer above the first interlayer comprising Ru or a Ru alloy, and a third interlayer formed between the first interlayer and the second interlayer that reduces an average cluster size of the second interlayer. The third interlayer has a thickness of between about 1.0 nm and about 3.0 nm and has a structure selected from a group consisting of: BCC, B2, C11b, L21, and D03. Other PMRMs and methods of fabrication are presented as well.
    Type: Application
    Filed: August 23, 2010
    Publication date: February 23, 2012
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yotsuo Yahisa, Ichiro Tamai, Akemi Hirotsune
  • Patent number: 8119263
    Abstract: A magnetic recording medium having a substrate, a first magnetic layer and a second magnetic layer, in this order, wherein an exchange coupling in the first magnetic layer is lower than an exchange coupling in the second magnetic layer, and the first and second magnetic layers are in a film stack so that magnetic grains in the first magnetic layer are exchange coupled by a pathway through the second magnetic layer is disclosed. A method of manufacturing a magnetic recording medium by obtaining a substrate, depositing a first magnetic layer at a first sputter gas pressure and depositing a second magnetic layer at a second sputter gas pressure, in this order, wherein the first sputter gas pressure is higher than the second sputter gas pressure, and an exchange coupling in the first magnetic layer is lower than an exchange coupling in the second magnetic layer is also disclosed.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: February 21, 2012
    Assignee: Seagate Technology LLC
    Inventors: Thomas Patrick Nolan, Samuel D. Harkness, IV
  • Patent number: 8119264
    Abstract: A perpendicular magnetic recording disk has a granular cobalt alloy recording layer (RL) containing an additive oxide or oxides, an intermediate layer (IL) as an exchange-break layer on the “soft” magnetic underlayer (SUL), and an ultrathin nucleation film (NF) between the IL and the RL. In the method of making the disk, the IL is deposited at a relatively low sputtering pressure, to thereby reduce the roughness of the RL and overcoat (OC), while the NF and RL are deposited at substantially higher sputtering pressures. The resulting disk has good recording properties and improved corrosion resistance over a comparable disk made with an IL deposited at high sputtering pressure and without the NF. The NF may be a discontinuous film with an average thickness of less than about 1 nm.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: February 21, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Ernesto E. Marinero
  • Patent number: 8114470
    Abstract: Aspects include recording media with enhanced areal density through reduction of head media spacing, head keeper spacing, or head to soft underlayer spacing. Such aspects comprise replacing currently non-magnetic components of devices, such as interlayers and overcoats with components and compositions comprising magnetic materials. Other aspects relate to magnetic seed layers deposited within a recording medium. Preferably, these aspects, embodied as methods, systems and/or components thereof reduce effective magnetic spacing without sacrificing physical spacing.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: February 14, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Bin Lu, Bogdan Florin Valcu, Xiaoding Ma