Single Magnetic Layer Patents (Class 428/836)
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Publication number: 20090169731Abstract: Patterned magnetic recording media and associated methods of fabrication are described. The patterned magnetic recording media includes a perpendicular magnetic recording layer that is patterned into a plurality of discrete magnetic islands. The patterned magnetic recording media also includes an exchange bridge structure formed from magnetic material that connects the islands of the perpendicular magnetic recording layer. Connecting the islands with magnetic material increases exchange coupling between the islands, which makes the islands more magnetically stable.Type: ApplicationFiled: December 26, 2007Publication date: July 2, 2009Inventors: Thomas R. Albrecht, Manfred E. Schabes
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Publication number: 20090162703Abstract: Not only chemical durability of a glass substrate for an information recording medium is improved, but also no deformation of the substrate and no alteration of substrate characteristics are to be made. A chemical treatment layer formed on the glass substrate surface is made thicker toward a large surface roughness portion of the glass substrate, prior to being subjected to a chemical treatment, from a small surface roughness portion of the glass substrate. Layer thickness D of the resulting chemical treatment layer preferably satisfies the following inequality (1) in view of acquisition of chemical durability. 100 Ra?D?3000 Ra??(1) wherein Ra is surface roughness of the glass substrate prior to being subjected to the chemical treatment.Type: ApplicationFiled: October 4, 2007Publication date: June 25, 2009Applicant: KONICA MINOLTAInventor: Hideki Kawai
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Patent number: 7544428Abstract: An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.Type: GrantFiled: October 13, 2005Date of Patent: June 9, 2009Assignee: Victor Company of Japan, LimitedInventors: Tetsuya Kondo, Kenji Oishi
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Publication number: 20090117409Abstract: A perpendicular magnetic recording medium and a method of manufacturing the same are provided. The perpendicular magnetic recording medium includes a substrate, and a recording layer comprising a plurality of independent first magnetic body regions and a plurality of second magnetic body regions formed on the substrate, the second magnetic body regions separating the first magnetic body regions from each other, and being formed by implanting dopant into a region in which the first magnetic body regions are to be separated. Each of the first magnetic body regions has an L10 structure and the dopant has an ionic or molecular shape.Type: ApplicationFiled: May 9, 2008Publication date: May 7, 2009Applicant: Samsung Electronics Co., Ltd.Inventors: Hoo-san LEE, Hoon-sang Oh
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Publication number: 20090061259Abstract: A bit patterned medium in which an exchange coupling layer induces exchange coupling between adjacent bits in order to reduce a switching field difference resulting from different magnetization directions of bits. The exchange coupling layer is disposed either over or under a recording layer having a plurality of bits. The exchange coupling layer induces exchange coupling between a bit which is to be recorded and an adjacent bit and reduces a switching field difference resulting from a difference between the magnetization direction of the bit to be recorded and the magnetization direction of neighboring bits due to an exchange coupling force generated during the exchange coupling.Type: ApplicationFiled: February 28, 2008Publication date: March 5, 2009Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Hoo-san LEE, Sung-chul LEE, Hoon-sang OH
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Patent number: 7498088Abstract: There are provided a magnetic thin film utilizing a granular film and having excellent high frequency characteristics and a method of manufacturing the same, and a multilayered magnetic film and magnetic components and electronic equipment utilizing the same. A nonreactive sputtering is performed so that there is no oxidation of a magnetic metal, and a saturation magnetization is increased to increase a resonant frequency of permeability. Also, a multi-target simultaneous sputtering is combined with the nonreactive sputtering so that in a granular structure including magnetic grains and an insulating layer a size of the magnetic grains and a thickness of the insulating layer are optimized thereby ensuring a proper magnitude for a crystalline magnetic anisotropy within the grains and excellent soft magnetic properties.Type: GrantFiled: May 11, 2004Date of Patent: March 3, 2009Assignee: Taiyo Yuden Co., Ltd.Inventors: Kazuyoshi Kobayashi, Kenji Ikeda, Masayuki Fujimoto
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Patent number: 7482070Abstract: A magnetic recording medium having high reliability is provided, in which concave portions between recording elements formed as convex portions of a concavo-convex pattern are approximately completely filled with a non-magnetic material. The magnetic recording medium is a plate-like body including: a substrate; a recording layer that is formed in a predetermined concavo-convex pattern over the substrate and includes recording elements for recording information formed as convex portions of the concavo-convex pattern; and the non-magnetic material filling concave portions between the recording elements. Side faces of the recording elements are inclined to face a surface of the plate-like body on a side toward which the recording elements 16 project in the concavo-convex pattern. An inclination angle of the side faces of the recording elements with respect to a direction perpendicular to that surface is smaller than 90° and 5° or more.Type: GrantFiled: April 27, 2005Date of Patent: January 27, 2009Assignee: TDK CorporationInventors: Mitsuru Takai, Yoshikazu Soeno, Katsumichi Tagami, Kazuya Shimakawa
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Patent number: 7468214Abstract: A tilted magnetic recording medium comprises a layer of magnetic material having a magnetic easy axis defined by tilted alignment of a particular crystalline phase of the magnetic material. A film of (101) and (011) textured L10 phase of a tetragonal crystalline magnetic material has crystalline c-axes oriented 45° to the medium surface normal. The L10 crystalline magnetic alloy comprises a first element selected from the group consisting of Co and Fe, and a second element selected from the group consisting of Pt and Pd. A seedlayer comprising a bcc or B2 crystal structure with a natural texture of (110) creates interfacial stress with the magnetic layer, giving rise to a pure (101) and (011) textured L10 crystalline film. A textured underlying surface facilitates preferential formation of the seedlayer and subsequent growth of the magnetic material to achieve tilted magnetic directions perpendicular to the recording tracks.Type: GrantFiled: July 5, 2005Date of Patent: December 23, 2008Assignee: Seagate Technology LLCInventors: Bin Lu, Dieter Weller
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Publication number: 20080311431Abstract: A magnetic multilayered film current element includes: at least one magnetic layer; at least one film structure containing a first insulating layer where a first opening is formed, a second insulating layer where a second opening is formed and a conductor disposed between the first insulating layer and the second insulating layer under the condition that a distance “A” between the first insulating layer and a portion of the second insulating layer at a position of the second opening is set larger than a closest distance “B” between the first insulating layer and the second insulating layer; and a pair of electrodes for flowing current to a magnetic multilayered film containing the at least one magnetic layer and the at least one film structure along a stacking direction of the magnetic multilayered film.Type: ApplicationFiled: June 11, 2008Publication date: December 18, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
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Publication number: 20080299416Abstract: 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: ApplicationFiled: January 23, 2008Publication date: December 4, 2008Applicant: Samsung Electronics Co., Ltd.Inventors: Seong-yong YOON, Chee-kheng Lim, Hoo-san Lee, Hoon-sang Oh, Sok-hyun Kong
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Patent number: 7449256Abstract: A method and system for magnetic recording using self-organized magnetic nanoparticles is disclosed. The method may include depositing surfactant coated nanoparticles on a substrate, wherein the surfactant coated nanoparticles represent first bits of recorded information. The surfactant coating is then removed from selected of the surfactant coated nanoparticles. The selected nanoparticles with their surfactant coating removed may then be designated to represent second bits of recorded information. The surfactant coated nanoparticles have a first saturation magnetic moment and the selected nanoparticles with the surfactant coating removed have a second saturation magnetic moment. Therefore, by selectively removing the surfactant coating from certain nanoparticles, a write operation for recording the first and second bits of information may be performed.Type: GrantFiled: December 21, 2005Date of Patent: November 11, 2008Assignee: Seagate Technology LLCInventors: René J. M. van de Veerdonk, Xiaowei Wu, Dieter K. Weller
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Publication number: 20080274380Abstract: The present invention provides a magnetic recording medium that excels in electromagnetic conversion characteristics. The magnetic recording medium has a 55 nm or less thickness magnetic layer formed on a major surface of an elongated nonmagnetic support by performing a vacuum thin film forming technique, the magnetic recording medium being slid over a magnetoresistive effect magnetic head or a giant magnetoresistive effect head to reproduce a signal, wherein an angle ? which is formed by a growth direction of magnetic particles in a columnar structure in a longitudinal cross-section of the magnetic layer and a normal to a longitudinal direction of the nonmagnetic support, satisfies the following relation: ?i??f?25°. where ?i is an angle of ? in an initial growth portion of the magnetic layer, and ?f is an angle of ? in a final growth portion of the magnetic layer.Type: ApplicationFiled: June 27, 2008Publication date: November 6, 2008Inventor: Kazunari Motohashi
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Publication number: 20080241601Abstract: The present invention provides a mold structure including: a concavo-convex pattern formed on its surface, wherein the mold structure is used for transferring the concavo-convex pattern onto an imprint resist layer formed on a surface of a substrate having a thickness of 0.3 mm to 2.0 mm by placing the concavo-convex pattern against the imprint resist layer, and wherein a thickness Dm (mm) of the mold structure, a thickness Ds (mm) of the substrate and a curl amount C (mm) of the mold structure satisfy the relationship 0.01?10,000×(Dm3/Ds3)1/2×C2?250.Type: ApplicationFiled: March 31, 2008Publication date: October 2, 2008Applicant: FUJIFILM CorporationInventors: Kenichi MORIWAKI, Toshihiro Usa, Masakazu Nishikawa
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Publication number: 20080220291Abstract: A magnetic paint is prepared by a method comprising a surface-treating step for magnetic powder, to obtain a first composition by mixing and stirring a composition which comprises a magnetic powder, a dispersant and/or a binder resin, and an organic solvent, and which contains 40% by weight or less of a non-solvent component, while applying a shear force to the composition; and a concentrating step to obtain a second composition by concentrating the first composition until the content of the non-solvent components of the first composition reaches 80% by weight or more.Type: ApplicationFiled: March 6, 2008Publication date: September 11, 2008Applicant: HITACHI MAXELL, LTD.Inventors: Kazuhiko Nakiri, Sadamu Kuse, Hiroyuki Mitsuhashi
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Publication number: 20080220290Abstract: To provide a magnetic recording medium manufacturing method capable of transferring a pattern that can serve as a source for forming anodized alumina-nanoholes with high precision and realizing high productivity, and a large-capacity magnetic recording medium capable of achieving high density recording. The method includes forming a metallic layer on a concavo-convex pattern formed on a surface of a mold; bonding a substrate using an adhesive to a surface of the metallic layer on the side opposite to the mold; separating the mold from the metallic layer; forming, through nanohole formation treatment, a porous layer in which a plurality of nanoholes are formed to orient in a direction substantially perpendicular to a substrate plane by using as a nanohole source a concavo-convex pattern which has been formed by transferring the concavo-convex pattern in the mold to the metallic layer; and charging a magnetic material inside the nanoholes.Type: ApplicationFiled: December 28, 2007Publication date: September 11, 2008Applicants: Fujitsu Limited, Kanagawa Academy of Science and TechnologyInventors: Ken-ichi Itoh, Hideyuki Kikuchi, Hiroshi Nakao, Hirotaka Oshima, Takahiro Umada, Hideki Masuda, Kazuyuki Nishio, Mitsuo Takeuchi, Hiroaki Date
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Patent number: 7413819Abstract: A magnetic recording medium is provided, which has a recording layer formed in a concavo-convex pattern and makes it possible to obtain the stable flying characteristics of a head. In the magnetic recording medium, concave portions between recording elements are filled with a non-magnetic material. Thus, the surface of the magnetic recording medium takes a concavo-convex shape which is different from the concavo-convex pattern of the recording layer. Also, the arithmetical mean deviation of the assessed profile of the concavo-convex shape in the surface is restricted to 1 nm or less.Type: GrantFiled: February 17, 2005Date of Patent: August 19, 2008Assignee: TDK CorporationInventors: Kazuhiro Hattori, Mitsuru Takai
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Publication number: 20080188165Abstract: A method for manufacturing a magnetic recording medium disk substrate is provided for achieving a magnetic disk having a suitable surface roughness, a high in-plane magnetic anisotropy and a high S/N. The manufacturing method has a texturing process wherein the magnetic recording medium disk substrate is rotated in the circumferential direction while a polishing tape is pressed against the rotating substrate. The polishing tape includes polyester fiber having a fiber diameter of 400 nm to 950 nm, on the surface coming into contact with the substrate. All the while, slurry including abrasive grains including a cluster diamond is supplied to the surfaces of the substrate. The present invention relates to a magnetic recording medium disk substrate produced by the manufacturing method; and a magnetic recording medium at least comprising a magnetic layer on the magnetic recording medium disk substrate and manufacturing method of the magnetic recording medium.Type: ApplicationFiled: December 21, 2007Publication date: August 7, 2008Applicants: Fuji Electric Device Technology Co., Ltd., Teijin Fibers LimitedInventors: Shoji Sakaguchi, Hiroyuki Nakamura, Hideki Matsuo
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Patent number: 7368186Abstract: The master carrier for magnetic transfer of the invention comprises a support and a magnetic layer formed on the surface of the support, wherein an uneven transfer pattern that corresponds to the information to be transferred to a magnetic recording medium is formed in the surface of the magnetic layer, and a relief is formed in the site where the transfer pattern is not formed.Type: GrantFiled: July 23, 2004Date of Patent: May 6, 2008Assignee: FUJIFILM CorporationInventors: Naoto Fujiwara, Seiji Kasahara, Kazuhiro Niitsuma
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Patent number: 7369336Abstract: A master carrier for magnetic transfer having a data region and a servo pattern region that has a pattern of fine projections arrayed in the track direction thereof in accordance with the preformat signal information to be transferred onto an in-plane magnetic recording medium is disclosed. The data region has a projection formed of a material such as carbon-based material that differs from the material of the servo pattern region.Type: GrantFiled: July 21, 2004Date of Patent: May 6, 2008Assignee: FUJIFILM CorporationInventors: Hideyuki Kubota, Akito Kamatani, Masakazu Nishikawa
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Publication number: 20070281078Abstract: According to one embodiment, a patterned media includes a magnetic film processed into patterns for tracks, servo zones or data zones, and a nonmagnetic filling material filled between patterns of the magnetic film for the tracks, servo zones or data zones and including a base material and a barrier material formed of a metal that does not constitute the base material.Type: ApplicationFiled: May 30, 2007Publication date: December 6, 2007Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai, Satoshi Shirotori
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Patent number: 7298569Abstract: A magnetic recording medium includes: an underlayer constituted of at least a substrate and a nonmagnetic metal element; and an amorphous magnetic layer, made of amorphous magnetic material, which magnetically records information. In certain example embodiments, the amorphous magnetic layer has bumps on a surface thereof or the magnetic recording medium has bumps on a surface thereof (surface of a lubricating layer) so that density of the bumps is not less than 400 bumps/?m2 or so that height of the bumps is not less than 2% with respect to an average layer thickness of the amorphous magnetic layer. Thus, magnetic wall movement of the amorphous magnetic layer is effectively suppressed, so that it is possible to stably form a recording bit.Type: GrantFiled: October 7, 2003Date of Patent: November 20, 2007Assignee: Sharp Kabushiki KaishaInventors: Junichi Sato, Hiroshi Fuji
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Publication number: 20070259210Abstract: A structure has a substrate and a layer containing a magnetic material dispersed in a nonmagnetic material, the magnetic material being comprised of first crystal particles having an easy magnetization axis crytsllographically oriented in the direction of the normal line of the substrate and forming columns perpendicular to the substrate and second crystal particles having a crystallographic orientation in a direction different from the direction of the crystallographic orientation in the first crystal particles, and the ratio of the second crystal particles to the entire crystal particles in the columns ranging from 10% to 50% by weight.Type: ApplicationFiled: April 26, 2007Publication date: November 8, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Shigeru Ichihara, Toru Den
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Publication number: 20070229998Abstract: A master for magnetic transfer is made which comprises a substrate which has on a surface thereof a convex area and a concave area corresponding to servo information and which is constituted of a soft magnetic, and a ferromagnetic which is provided in the concave portion of the substrate, which has a coercive force larger than the external magnetic field for reversing the direction of magnetization of the vertical recording medium, and which has magnetization in a direction opposite to the direction of the external magnetic field.Type: ApplicationFiled: August 21, 2006Publication date: October 4, 2007Inventors: Sumio Kuroda, Takeshi Morikawa
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Publication number: 20070224455Abstract: A magnetic recording medium includes a continuous recording layer, and a seed layer including a surface held in contact with the recording layer. The seed layer includes an oxidized region and a non-oxidized region in the surface held in contact with the recording layer. The recording layer includes a recording magnetic region and a non-recording magnetic region. The recording magnetic region corresponds in position to the non-oxidized region and has perpendicular magnetic anisotropy. The non-recording magnetic region corresponds in position to the oxidized region.Type: ApplicationFiled: March 22, 2007Publication date: September 27, 2007Inventors: Koichi Iida, Kazuyuki Ozaki
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Publication number: 20070218318Abstract: A magnetic recording medium having magnetic dots that can achieve high density recording is disclosed. The magnetic recording medium comprises at least an underlayer, a magnetic recording layer, and a protective layer sequentially laminated on a nonmagnetic substrate. The underlayer is composed of ruthenium or an alloy of mainly ruthenium and has an undulating structure formed with ridge lines in a predetermined pitch on the surface of the underlayer. The magnetic recording layer contains at least ferromagnetic crystal grains and a nonmagnetic component. Magnetic dots composed of crystal grains with a grain size not smaller than 4 nm in the magnetic recording layer are aligned on a surface of the underlayer along the ridge line, and each of the magnetic dots s separated by the nonmagnetic component from each other. A simple manufacturing method for this medium also is disclosed.Type: ApplicationFiled: March 7, 2007Publication date: September 20, 2007Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventor: Sadayuki WATANABE
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Patent number: 7258935Abstract: A magnetic recording medium having a magnetic layer with a single-layered structure applicable to a linear system is provided. The magnetic recording medium includes an elongated nonmagnetic support and a single-layered magnetic layer having an orthorhombic structure formed on a main surface of the nonmagnetic support by a vacuum thin film deposition technique, and an Hcmax/Hx0 ratio is not greater than 1.2, where Hcmax is a maximum value of a coercive force of the magnetic layer which acts in a plane perpendicular to the magnetic layer and containing a longitudinal direction of the magnetic recording medium, and Hc0 is a coercive force of the magnetic layer which acts in the longitudinal direction of the magnetic recording medium.Type: GrantFiled: April 15, 2004Date of Patent: August 21, 2007Assignee: Sony CorporationInventor: Kazunari Motohashi
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Patent number: 7232621Abstract: A method of patterning magnetic material includes forming a ferromagnetic material layer containing one element selected from the group consisting of Fe, Co and Ni on a substrate, selectively masking a surface of the ferromagnetic material layer, and making nonferromagnetic. The making nonferromagnetic step includes exposing an exposed portion in halogen-containing reaction gas, changing magnetism of the exposed portion and a lower layer thereof by chemical reaction, and making the exposed portion a nonferromagnetic material region. A magnetic recording medium is fabricated by using the magnetic material patterning method and includes a plurality of recording regions made of ferromagnetic materials, each containing at least one element selected from the group consisting of Fe, Co and Ni, and a nonferromagnetic material region for separating the recording regions from each other. The nonferromagnetic material region is a compound region of the ferromagnetic material and halogen.Type: GrantFiled: July 7, 2004Date of Patent: June 19, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiyuki Kamata, Katsuyuki Naito, Hiroyuki Hieda
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Patent number: 7218465Abstract: A stamper/imprinter for use in forming a magnetic transition pattern in a magnetic material by means of contact printing, comprising: (a) a non-magnetic substrate having a major surface comprising a patterned plurality of spaced-apart recesses with a plurality of non-recessed areas therebetween, the patterned plurality of recesses corresponding to the magnetic transition pattern to be formed in the magnetic material; and (b) unidirectionally permanently magnetized material filling each of the plurality of recesses and having exposed surfaces substantially coplanar with the plurality of non-recessed areas.Type: GrantFiled: June 4, 2003Date of Patent: May 15, 2007Assignee: Seagate Technology LLCInventors: Neil Deeman, Shih-Fu Lee
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Patent number: 7199953Abstract: A favorable magnetic transfer is performed to a perpendicular magnetic recording medium. A master medium is provided with a substrate on the surface of which protrusion portions, which form a pattern corresponding to the data that is to be transferred, having a pliable layer thereon have been formed. The master medium is further provided with a soft magnetic layer formed in the depression portions between the protrusion portions, and which is magnetically linked to the soft magnetic layer of the protrusion portions. The soft magnetic layer of the surface of the protrusion portions is conjoined with the magnetic recording layer of a perpendicular magnetic recording medium to form a conjoined body, and a transfer magnetic field is applied to the conjoined body in the direction from the substrate of the master medium toward the slave medium to perform the magnetic transfer.Type: GrantFiled: May 12, 2004Date of Patent: April 3, 2007Assignee: Fujifilm CorporationInventors: Masakazu Nishikawa, Kazunori Komatsu
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Patent number: 7157162Abstract: A magnetic recording medium having a substrate, an under-layer formed on the substrate, a magnetic layer formed on the substrate and a protective layer formed on the magnetic layer. The magnetic layer comprises Co, Cr and Pt with a thickness being from 10 nm to 22 nm. Further, a coercivity of the magnetic layer is not less than 2000 Oe, and a fluctuation field of magnetic viscosity at a field strength equal to remanence coercivity or coercivity is not less than 30 Oe.Type: GrantFiled: January 18, 2005Date of Patent: January 2, 2007Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Kazusuke Yamanaka, Tomoo Yamamoto, Yuzuru Hosoe, Nobuyuki Inaba, Yasutaro Uesaka, Masaaki Futamoto, Yoshibumi Matsuda, Kenji Furusawa, Shinji Narishige
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Patent number: 7153597Abstract: A data storage medium is provided according to the present invention for magnetic recording. The data storage medium includes a substrate having a locking pattern etched therein defining patterned regions. The patterned regions are chemically modified by depositing a self-assembled monolayer therein. A first layer of nanoparticles is provided in the patterned regions on top of the self-assembled monolayer and is chemically bonded to the substrate via the self-assembled monolayer. The first layer of nanoparticles is chemically modified using functional surfactant molecules applied thereto, such that a second layer of nanoparticles may be formed on top of the first layer and chemically bonded thereto via the functional surfactant molecules. Additional layers of nanoparticles may be applied by chemically modifying the top layer of nanoparticles utilizing the functional surfactant molecules and applying a further layer of nanoparticles thereto.Type: GrantFiled: October 9, 2003Date of Patent: December 26, 2006Assignee: Seagate Technology LLCInventors: Xiaomin Yang, Earl C. Johns, Timothy J. Klemmer, Chao Liu, Dieter K. Weller
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Patent number: 7067207Abstract: A magnetic recording medium includes a non-magnetic substrate; a soft magnetic layer which is formed on the non-magnetic substrate and which includes projected parts arranged on the surface thereof and recessed parts surrounding each of the projected part; and a ferromagnetic layer which is formed on the soft magnetic layer and which includes projected parts and recessed parts reflecting the projected parts and the recessed parts of the soft magnetic layer. Further the magnetic recording medium includes recording areas which have perpendicular magnetic anisotropy and ferromagnetism, and which are formed of the projected parts of the ferromagnetic layer and separated magnetically from their surroundings.Type: GrantFiled: November 7, 2003Date of Patent: June 27, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiyuki Kamata, Masatoshi Sakurai, Akira Kikitsu
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Patent number: 7041394Abstract: A magnetic recording disc is provided according to the present invention for magnetic recording. The magnetic recording disc includes a disc substrate having a locking pattern etched therein. Chemically synthesized iron-platinum particles are provided in the locking pattern and completely fill the locking pattern. The chemically synthesized iron-platinum nanoparticles exhibit short-range order characteristics forming self organized magnetic arrays.Type: GrantFiled: December 3, 2001Date of Patent: May 9, 2006Assignee: Seagate Technology LLCInventors: Dieter Klaus Weller, Neil Deeman, Rene Johannes Marinus van de Veerdonk, Nisha Shukla
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Patent number: 7029773Abstract: A method and system for magnetic recording using self-organized magnetic nanoparticles is disclosed. The method may include depositing surfactant coated nanoparticles on a substrate, wherein the surfactant coated nanoparticles represent first bits of recorded information. The surfactant coating is then removed from selected of the surfactant coated nanoparticles. The selected nanoparticles with their surfactant coating removed may then be designated to represent second bits of recorded information. The surfactant coated nanoparticles have a first saturation magnetic moment and the selected nanoparticles with the surfactant coating removed have a second saturation magnetic moment. Therefore, by selectively removing the surfactant coating from certain nanoparticles, a write operation for recording the first and second bits of information may be performed.Type: GrantFiled: October 10, 2003Date of Patent: April 18, 2006Assignee: Seagate Technology LLCInventors: René J. M. van de Veerdonk, Xiaowei Wu, Dieter K. Weller
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Patent number: 6982127Abstract: An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.Type: GrantFiled: June 4, 2003Date of Patent: January 3, 2006Assignee: Victor Company of Japan, Ltd.Inventors: Tetsuya Kondo, Kenji Oishi