Multiple Magnetic Layers Patents (Class 428/827)
  • Patent number: 7867637
    Abstract: A low-coupling perpendicular magnetic recording media comprising a magnetic storage layer and at least one low saturation magnetization layer. The magnetic storage layer has a saturation magnetization between about 400-900 emu/cm3 and the at least one low saturation magnetization layer has a saturation magnetization below that of the magnetic storage layer.
    Type: Grant
    Filed: November 17, 2008
    Date of Patent: January 11, 2011
    Assignee: Seagate Technology LLC
    Inventors: Erol Girt, Hans Jurgen Richter, Mariana R. Munteanu, Thomas Nolan
  • Patent number: 7862912
    Abstract: A perpendicular magnetic recording medium, usable for either continuous or patterned media, has a recording layer structure (RLS) of first and second perpendicular magnetic layers (PM1, PM2) and an antiferromagnetically coupling (AFC) layer and a ferromagnetic switching layer (SWL) between PM1 and PM2. The magnetic recording system uses heat to assist in the reading and/or writing of data. The SWL is a Co/Ni multilayer with a Curie temperature (TC-SWL) less than the Curie temperatures of PM1 and PM2. At room temperature, there is ferromagnetic coupling between SWL and the upper ferromagnetic layer (PM2) so that the magnetizations of SWL and PM2 are parallel, and antiferromagnetic coupling between SWL and the lower ferromagnetic layer (PM1) across the AFC layer so that the magnetization of PM1 is aligned antiparallel to the magnetizations of SWL and PM2.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: January 4, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Olav Hellwig, Bruce David Terris, Jan-Ulrich Thiele
  • Patent number: 7846563
    Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 may have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAG1 with MAG2. The LCL is located either above or below MAG1 and in direct contact with MAG1 and mediates an effective intergranular exchange coupling in MAG1. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG1, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: December 7, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Andreas Klaus Berger, Eric E. Fullerton, Byron Hassberg Lengsfield, III, David Thomas Margulies
  • Patent number: 7842408
    Abstract: Embodiments of the present invention provide a magnetic disk drive capable of allowing higher data transfer rates and higher recording densities. According to one embodiment, an upper magnetic core and lower magnetic core comprise a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is about 30±1° C., pH is about 2.0?1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Since each layer's crystal structure is different from that of its adjacent lower layer, epitaxial growth is broken within each layer.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: November 30, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kazue Kudo, Gen Oikawa, Yohji Maruyama, Noriyuki Saiki, Hiromi Shiina
  • Publication number: 20100279151
    Abstract: A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.
    Type: Application
    Filed: October 14, 2008
    Publication date: November 4, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Kazuaki Sakamoto, Kong Kim, Takahiro Onoue, Masafumi Ishiyama, Teiichiro Umezawa, Kenji Ayama
  • Patent number: 7821366
    Abstract: In a magnetic circuit for providing magnetic anisotropy in the in-plane radial direction of a soft magnetic under layer, magnets for perpendicular magnetization are respectively provide on the north and south poles of a magnet for horizontal magnetization. When magnetic circuits configured thus are stacked in a plurality of stages, a magnetic field (air-gap magnetic field) formed in a gap between the magnetic circuits is superimposed by magnetic fields from the magnets for perpendicular magnetization as well as a magnetic field from the magnet for horizontal magnetization (in-plane magnetization). The pole faces of the magnets for perpendicular magnetization are disposed closer to the gap between the magnetic circuits, so that a stronger magnetic field can be formed in the gap.
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: October 26, 2010
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventor: Ken Ohashi
  • Patent number: 7807278
    Abstract: A perpendicular magnetic recording medium, including a soft-magnetic backing layer; and a recording layer provided over the oft-magnetic backing layer. There is provided a magnetic flux slit layer between the soft-magnetic backing layer and the recording layer. The magnetic flux slit layer includes a soft-magnetic layer having a generally columnar structure generally isolated magnetically in an in-plane direction. The magnetic flux slit layer contains at least one selected from the group consisting of Co, Fe, Ni, a Co alloy, a Fe alloy, and a Ni alloy, as a major component, and the magnetic flux slit layer further contains any one selected from the group consisting of Ta, Cu, Pb, Cr, and Re.
    Type: Grant
    Filed: March 24, 2006
    Date of Patent: October 5, 2010
    Assignee: Showa Denko K.K.
    Inventors: Toshio Sugimoto, Ryosaku Inamura, Takuya Uzumaki
  • Publication number: 20100247969
    Abstract: Multiple anisotropy layered magnetic structures for controlling reversal mechanism and tightening of switching field distribution in bit patterned media are disclosed. The invention extends the exchange spring concept to more variable and sophisticated structures. Three or more layers with different anisotropy or anisotropy gradients increase writeability gains beyond the simple hard/soft bilayer exchange spring concept for BPM. The structures have a thin very hard, high anisotropy center layer that acts as a threshold or pinning layer for domain wall propagation through the entire media structure. In addition or alternatively, a thin very soft, low anisotropy center layer in between the commonly used soft surface layer and hard media layer allows quick initial propagation of the domain wall into the center of the media structure. Various properties of the media structures can be tuned more independently for optimization if using more advanced multi-anisotropy layer stacks.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas Hauet, Olav Hellwig, Manfred Ernst Schabes
  • Patent number: 7803470
    Abstract: One inventive aspect relates to a high-frequency magnetic thin film capable of working in a GHz-level band, and an electronic device comprising the film. The film comprises a magnetic layer and an insulating layer that are laminated alternately. The magnetic layer includes a first magnetic layer and a second magnetic layer. The first magnetic layer has a higher anisotropic magnetic field than the second magnetic layer, and the second magnetic layer has a higher saturation magnetization than the first magnetic layer.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: September 28, 2010
    Assignee: Taiyo Yuden Co.,Ltd.
    Inventor: Kenji Ikeda
  • Patent number: 7781079
    Abstract: A perpendicular magnetic recording medium includes a substrate, a soft magnetic lining layer formed on the substrate, and a recording layer. The recording layer includes a first recording layer, an auxiliary recording layer, and a second recording layer that are laminated in this sequence. The first and the second recording layers are ferromagnetic layers that have a magnetization easy axis perpendicular to the layers. The auxiliary recording layer includes two or more magnetic particles mutually separated by non-magnetism members, wherein the magnetic particles are arranged approximately perpendicular to the layer and have the magnetization easy axis in a direction slanted with reference to the layer. The auxiliary recording layer is exchange-coupled with the adjoining first recording layer and second recording layer.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: August 24, 2010
    Assignee: Showa Denko K.K.
    Inventor: Ryo Kurita
  • Publication number: 20100209737
    Abstract: Aspects are directed to recording media with enhanced magnetic properties for improved writability. Examples can be included or related to methods, systems and components that allow for improved writability while reducing defects so as to obtain uniform magnetic properties such as uniformly high anisotropy and narrow switching field distribution. Some examples include a recording medium with an exchange tuning layer inserted between the hard layer and the soft, semi-soft or thin semi-hard layer so as to maximize the writability improvement of the media. Preferably, the exchange tuning layer is granular and reduces or optimizes the vertical coupling between the hard layer and the soft, semi-soft or semi-hard layer of a magnetic recording or storing device.
    Type: Application
    Filed: February 19, 2009
    Publication date: August 19, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Bo Bian, Shoutao Wang, Weilu Xu, Abebe Hailu, Miaogen Lu, Charles C. Chen, Thomas Patrick Nolan, Alexander Yulievich Dobin
  • Publication number: 20100209738
    Abstract: Disclosed is a thin film material including a substrate and an underlying layer formed on the substrate. A large number of recesses of an extremely small size are demonstrated in a surface of the underlying layer. On this surface of the underlying layer is formed a magnetic film or a non-magnetic film.
    Type: Application
    Filed: February 18, 2010
    Publication date: August 19, 2010
    Applicant: NIHON UNIVERSITY
    Inventors: Akiyoshi Itoh, Katsuji Nakagawa, Arata Tsukamoto
  • Publication number: 20100209736
    Abstract: One object of the present invention is to provide a method for easily providing an ECC type magnetic recording medium with low cost, which is easily designed, and the present invention provides a perpendicular magnetic recording medium including at least a soft magnetic backing layer, an under layer, an intermediate layer, and a perpendicular magnetic recording layer on a non-magnetic substrate, wherein the perpendicular magnetic recording layer includes at least one of a main recording layer and an auxiliary recording layer, the main recording layer includes a layer having perpendicular magnetic anisotropy, the auxiliary recording layer is a multilayer including three or more of a soft magnetic layer and a non-magnetic layer which are layered alternately, and the outermost layer to the non-magnetic substrate is the soft magnetic layer.
    Type: Application
    Filed: September 4, 2008
    Publication date: August 19, 2010
    Applicant: Showa Denko K.K.
    Inventor: Atsushi Hashimoto
  • Patent number: 7771852
    Abstract: A magnetic recording disk has patterned nondata regions that are used for read/write head positioning and data synchronization. The nondata regions contain nondata islands of magnetizable material separated by nonmagnetic spaces with the nondata islands having alternating magnetization polarity in the along-the-track direction. In each nondata region, every other nondata island in the along-the track direction has the same magnetization direction, with adjacent nondata islands having antiparallel magnetization directions. The disk may be either a horizontal magnetic recording disk, wherein the antiparallel magnetization directions are in the plane of the recording layer and parallel to the along-the-track direction, or a perpendicular magnetic recording disk, wherein the antiparallel the magnetization directions are “into” and “out of” the recording layer.
    Type: Grant
    Filed: June 9, 2005
    Date of Patent: August 10, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas R. Albrecht, Zvonimir Bandic
  • Publication number: 20100196740
    Abstract: A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate 110, a soft magnetic layer 14, a magnetic recording layer 22, a continuous layer 24 magnetically continuous in the in-plane direction of the substrate, a blocking layer 25 for blocking shock imposed on the continuous layer, and a medium protective layer 28 containing carbon formed on the blocking layer.
    Type: Application
    Filed: September 24, 2008
    Publication date: August 5, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE LTD
    Inventors: Kenji Ayama, Tokichiro Sato, Teiichiro Umezawa, Masafumi Ishiyama
  • Publication number: 20100190035
    Abstract: [Problems] To provide a reinforcing layer between a main recording layer and a continuous layer so as to improve the S/N ratio of a magnetic recording medium and reduce the write fringing effect by the new configuration. [Means for Solving Problems] A perpendicular magnetic recording medium (100) includes a substrate (110), and a main recording layer (122), a reinforcing layer (124), and a continuous layer (126) which are overlaid in this order on the substrate. The reinforcing layer (124) has a granular structure. The saturation magnetization Ms of the reinforcing layer (124) is higher than the saturation magnetization of the main recording layer (122).
    Type: Application
    Filed: May 30, 2008
    Publication date: July 29, 2010
    Applicant: HOYA CORPORATION
    Inventors: Yoshiaki Sonobe, Kong Kim
  • Publication number: 20100182714
    Abstract: A thermal-assist magnetic recording medium is provided which can accomplish a surface recording density of 1 Tbit/inch2. The thermal-assist magnetic recording medium includes: a substrate; a plurality of underlying layers formed on the substrate; a first magnetic layer formed on the underlying layers; a coupling control layer formed on the first magnetic layer and formed of a ferromagnetic alloy; and a second magnetic layer formed on the coupling control layer. Here, Curie temperatures of the first magnetic layer and the second magnetic layer are higher than the Curie temperature of the coupling control layer, an anisotropy magnetic field of the first magnetic layer is greater than the anisotropy magnetic field of the second magnetic layer, and a saturation magnetic field has a minimum value at a temperature of 350° C. or lower.
    Type: Application
    Filed: November 30, 2009
    Publication date: July 22, 2010
    Applicant: SHOWA DENKO K.K.
    Inventors: Tetsuya KANBE, Yuzo Sasaki, Atsushi Hashimoto
  • Publication number: 20100178529
    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: Application
    Filed: March 24, 2010
    Publication date: July 15, 2010
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventor: Ernesto E. Marinero
  • Publication number: 20100159283
    Abstract: A magnetic storage medium includes a substrate, a first magnetic layer film that is deposited on the substrate, and a second magnetic layer film that is a cap layer of the first magnetic layer film. The first magnetic layer film contains a high magnetic anisotropic material and a low-temperature diffusion material which is added to the high magnetic anisotropic material, the low-temperature diffusion material starting diffusion by thermal treatment at a lower temperature than that of the high magnetic anisotropic material. The second magnetic layer film includes a material for promoting diffusion of the low-temperature diffusion material.
    Type: Application
    Filed: October 20, 2009
    Publication date: June 24, 2010
    Applicant: SHOWA DENKO K.K.
    Inventors: Takahiro IBUSUKI, Masashige SATO
  • Patent number: 7732069
    Abstract: A disk drive system having a shielded pole write head and media that includes a disk having a soft underlayer (SUL) that is relatively thin in order to save on cost for producing the SUL. The SUL is thin enough that it will become magnetically saturated in the vicinity of the write pole. The thickness of the SUL that will achieve this saturation may be stated as being less than a geometric factor times the ratio of the write pole saturation magnetization divided by the saturation magnetization of the SUL. The geometric factor is the ratio of the write pole area at the ABS to the write pole perimeter at the ABS.
    Type: Grant
    Filed: June 9, 2005
    Date of Patent: June 8, 2010
    Assignee: Seagate Technology LLC
    Inventors: Mourad Benakli, Michael Mallary, Adam Torabi
  • Publication number: 20100128390
    Abstract: The invention provides a method of forming a magnetic layer with stable magnetic properties and stable recording-and-reproducing properties, by uniformizing the distribution of oxygen radical concentration upon reactive sputtering, and thereby uniformizing the concentration of oxygen to be taken into the magnetic layer along the plane direction.
    Type: Application
    Filed: November 9, 2009
    Publication date: May 27, 2010
    Applicant: SHOWA DENKO K.K.
    Inventor: Takashi TANAKA
  • Publication number: 20100129685
    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: November 26, 2008
    Publication date: May 27, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Bin Lu, Bogdan Florin Valcu, Xiaoding Ma
  • Patent number: 7718282
    Abstract: A magnetic recording medium with a granular magnetic recording layer excellent in corrosion resistance is provided. In one embodiment, after formation of, on a non-magnetic substrate, an NiTa adhesion layer, a soft magnetic layer, a Ta intermediate layer, an Ru intermediate layer, and a Co alloy granular magnetic recording layer, hydrogen (H2) plasma processing is applied to the surface of the Co alloy granular magnetic recording layer. Then, a DLC protective film layer is formed and a lubricant layer is coated.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: May 18, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shigehiko Fujimaki, Toshinori Ono, Mitsuhiro Shoda
  • Publication number: 20100119876
    Abstract: A magnetic recording medium includes a substrate, and a soft magnetic layer, a crystal orientation control layer, a magnetic recording layer, and a protective layer formed sequentially on the substrate. The magnetic recording layer includes at least one granular magnetic layer having a granular structure and a non-granular magnetic layer having a non-granular structure. The at least one granular magnetic layers includes a plurality of magnetic portions and a separation portion surrounding the magnetic portions. The separation portion has magnetic characteristics different from the magnetic characteristics of the magnetic portions. The non-granular magnetic layer is a continuous film.
    Type: Application
    Filed: November 6, 2009
    Publication date: May 13, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventor: Shinji Uchida
  • Publication number: 20100119877
    Abstract: A corrosion-resistant granular magnetic recording medium with improved recording performance comprises a non-magnetic substrate having a surface; and a layer stack on the substrate surface, including, in order from the surface: a granular magnetic recording layer; an intermediate magnetic de-coupling layer; and a corrosion preventing magnetic cap layer. The intermediate magnetic de-coupling layer has an optimal thickness and/or composition for: (1) promoting magnetic exchange de-coupling between the granular magnetic recording layer and the magnetic cap layer; and (2) reducing the dynamic closure field (Hcl) for determining writeability and eraseability of the medium. Grain boundaries of the magnetic cap layer are substantially oxide-free, and have a greater density and lower average porosity and surface roughness than those of the granular magnetic recording layer.
    Type: Application
    Filed: January 14, 2010
    Publication date: May 13, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Michael Zyee-Shan Wu, Mason Lu, Kueir W. Chour, Connie C. Liu, Edward T. Yen, Lynn Li, Steve Hwang
  • Patent number: 7704614
    Abstract: A method of fabricating a patterned magnetic recording medium, comprises steps of: (a) providing a layer stack including an uppermost non-magnetic interlayer; (b) forming a resist layer on the interlayer; (c) forming a first pattern comprising a first group of recesses extending through the resist layer and exposing a first group of spaced apart surface portions of the interlayer; (d) filling the first group of recesses with a layer of a hard mask material; (e) selectively removing the resist layer to form a second pattern comprising a second group of recesses extending through the hard mask layer and exposing a second group of spaced apart surface portions of the interlayer; and (f) filling the second group of recesses with a layer of a magnetically hard material forming a magnetic recording layer.
    Type: Grant
    Filed: October 20, 2006
    Date of Patent: April 27, 2010
    Assignee: Seagate Technology LLC
    Inventors: Kim Y. Lee, Hong Ying Wang, Nobuo Kurataka, Christopher Formato, David S. Kuo, Dieter K. Weller
  • Patent number: 7701667
    Abstract: Embodiments in accordance with the present invention provide a perpendicular recording medium with low noise and high recording density by reducing the effects from noise generated from the vicinity of the interface with the intermediate layer of the recording layer, in a perpendicular recording medium utilizing a granular recording layer containing oxygen or oxide additive in a cobalt-chromium alloy formed on an intermediate layer with a ruthenium or ruthenium alloy layer. A first recording layer and a second recording layer are formed in order on an intermediate layer of ruthenium or ruthenium alloy. The first recording layer and the second recording layer are comprised of cobalt as the main material in a granular structure containing chromium and oxygen. The saturation magnetization of the first recording layer is lower than the saturation magnetization of the second recording layer.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: April 20, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ichiro Tamai, Ikuko Takekuma, Hiroaki Nemoto, Yoshiyuki Hirayama
  • Publication number: 20100091402
    Abstract: The invention uses an adhesion layer of an amorphous alloy of aluminum. A first aluminum titanium embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %). A second embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %) and up to 10 at. % Zr with 5 at. % Zr being preferred. A third embodiment is aluminum tantalum preferably including from 15 to 25 at. % tantalum with 20 at. % being preferred. The most preferred compositions are Al50Ti50, Al47.5Ti47.5Zr5 or Al80Ta20. The adhesion layer is deposited onto the substrate. The substrate can be glass or a metal such as NiP-plated AlMg. The preferred embodiment of media according to the invention is for perpendicular recording and includes a magnetically soft underlayer deposited above the adhesion layer.
    Type: Application
    Filed: December 9, 2009
    Publication date: April 15, 2010
    Inventors: Hong Deng, Yoshihiro Ikeda, Mary Frances Minardi, Kentaro Takano, Kai Tang
  • Patent number: 7691499
    Abstract: A corrosion-resistant granular magnetic recording medium with improved recording performance comprises a non-magnetic substrate having a surface; and a layer stack on the substrate surface, including, in order from the surface: a granular magnetic recording layer; an intermediate magnetic de-coupling layer; and a corrosion preventing magnetic cap layer. The intermediate magnetic de-coupling layer has an optimal thickness and/or composition for: (1) promoting magnetic exchange de-coupling between the granular magnetic recording layer and the magnetic cap layer; and (2) reducing the dynamic closure field (Hcl) for determining writeability and eraseability of the medium. Grain boundaries of the magnetic cap layer are substantially oxide-free, and have a greater density and lower average porosity and surface roughness than those of the granular magnetic recording layer.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: April 6, 2010
    Assignee: Seagate Technology LLC
    Inventors: Michael Zyee-Shan Wu, Mason Lu, Kueir W. Chour, Connie C. Liu, Edward T. Yen, Lynn Li, Steve Hwang
  • Patent number: 7691500
    Abstract: Embodiments of the present invention help to provide an excellent perpendicular recording medium of high medium signal-to-noise (S/N) and with suppressed blurring in writing. According to one embodiment, a perpendicular recording layer is provided by way of a negative magnetic strain soft-magnetic underlayer above a substrate applied with texturing in the circumferential direction. The soft-magnetic underlayer has a first soft magnetic layer, a second soft magnetic layer and a nonmagnetic magnetic layer formed between the first soft magnetic layer and the second soft magnetic layer in which the first soft magnetic layer and the second soft magnetic layer are antiferromagnetically coupled to each other and the easy magnetization axis is directed in the radial direction.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: April 6, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masayoshi Shimizu, Reiko Arai
  • Publication number: 20100055502
    Abstract: A tunneling magnetoresistive device includes: a fixed layer that includes a ferromagnetic material; a tunneling insulating film that is provided in contact with the fixed layer; and a free layer that includes a first ferromagnetic film provided in contact with the tunneling insulating film, a second ferromagnetic film whose magnetization is coupled parallel to the magnetization of the first ferromagnetic film, and a conductive film interposed between the first ferromagnetic film and the second ferromagnetic film.
    Type: Application
    Filed: August 26, 2009
    Publication date: March 4, 2010
    Applicant: Nat Inst of Adv Industrial Sci and Tech
    Inventors: Hitoshi KUBOTA, Akio FUKUSHIMA, Kei YAKUSHIJI, Shinji YUASA, Koji ANDO, Satoshi YAKATA
  • Patent number: 7666529
    Abstract: A magnetic recording medium having a first magnetic layer, a spacer layer, and a second magnetic layer, in this order, wherein the spacer layer includes a non-magnetic layer and a thickness of the spacer layer is selected to establish anti-ferromagnetic coupling between the first magnetic layer and the second magnetic layer, and a thickness of both the first and second magnetic layers are less than a critical thickness for formation of stripe domains in the magnetic layers is disclosed.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: February 23, 2010
    Assignee: Seagate Technology LLC
    Inventors: Erol Girt, Charles Frederick Brucker, Alexander Yulievich Dobin
  • Patent number: 7662491
    Abstract: Disclosed is a method for manufacturing a template for a high-density patterned medium and a high-density magnetic storage medium using the same. In the method, magnetic particles are used as a mask and no lithographic process is required.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: February 16, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hae Sung Kim, Myung Bok Lee, Jin Seung Sohn
  • Patent number: 7655324
    Abstract: An electro-magnetic storage device and method are disclosed. In one embodiment, a memory device includes a first magnetic material to attract a movable structure (e.g., a ferromagnetic material) when a first voltage is applied between the first magnetic material and the movable structure, and a second magnetic material to release the movable structure when a second voltage is applied between the second magnetic material and the movable structure. The movable arm may create a closed circuit when the second voltage is applied between the second magnetic material and the movable structure. There may be a vacuum-gap between the movable structure and at least one of the first magnetic material and/or the second magnetic material. The memory device may be stackable on other memory devices having similar properties, and/or electrically coupled with other memory devices having similar properties in a memory array.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: February 2, 2010
    Inventor: Sridhar Kasichainula
  • Publication number: 20100021768
    Abstract: [PROBLEMS] To improve the track density by reducing the track edge noise and sharpening the boundaries of a recording magnetic field by blocking the recording magnetic field spreading outside the recording region in magnetic recording. [MEANS FOR SOLVING PROBLEMS] A magnetic recording medium (10) has a substrate (12) and a perpendicular magnetic recording layer (30) formed over the substrate (12). The perpendicular magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20).
    Type: Application
    Filed: February 13, 2008
    Publication date: January 28, 2010
    Inventors: Yoshiaki Sonobe, Takahiro Onoue, Koichi Wago
  • Publication number: 20100014191
    Abstract: This invention provides a perpendicular magnetic recording medium which has magnetic layers of a stabilized laminated structure and excels in the recording and reproducing property. The perpendicular magnetic recording medium of this invention comprises at least an underlayer, a seed layer, a first intermediate layer, a second intermediate layer, a first magnetic recording layer, a second magnetic recording layer, and a protecting layer laminated in the order mentioned on a nonmagnetic substrate. The first intermediate layer is formed of an alloy having Ru as a main constituent and the second intermediate layer is formed of a CoCr alloy containing no Ru. An alloy layer of a composition having Ru element as an essential constituent is sandwiched between the first magnetic recording layer and the second magnetic recording layer. Further, the first magnetic recording layer is formed of a magnetic alloy containing Ru.
    Type: Application
    Filed: July 10, 2009
    Publication date: January 21, 2010
    Applicant: SHOWA DENKO K.K.
    Inventor: Hiroshi KANAZAWA
  • Publication number: 20100009218
    Abstract: The invention relates to a perpendicular magnetic recording medium comprising a substrate and a granular magnetic layer comprising ruthenium or ruthenium oxide in the grain boundaries.
    Type: Application
    Filed: July 8, 2008
    Publication date: January 14, 2010
    Applicant: Seagate Technology LLC
    Inventors: Jeffrey Shane Reiter, Steven Eric Barlow
  • Publication number: 20090296278
    Abstract: A perpendicular magnetic recording medium includes a nonmagnetic seed layer, a nonmagnetic intermediate layer provided on the nonmagnetic seed layer, and a perpendicular recording layer provided on the nonmagnetic intermediate layer. The nonmagnetic seed layer includes a first seed layer made of an amorphous material, and a second seed layer provided between the first seed layer and the nonmagnetic intermediate layer and made of a material having a fcc structure. The amorphous material includes at least one element selected from a group consisting of Ta, W, Nb, Mo, Zr and alloys thereof which include at least one of Ta, W, Nb, Mo and Zr as a main component exceeding 50 at. %.
    Type: Application
    Filed: March 12, 2009
    Publication date: December 3, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Ryosaku Inamura, Yuta Toyoda
  • Publication number: 20090291328
    Abstract: This application relates to a new process for the application of thin layers of substantially pure spin transition molecular materials while maintaining the hysteresis properties of the material. The process makes it possible to obtain a dense uniform surface with very low roughness.
    Type: Application
    Filed: March 19, 2007
    Publication date: November 26, 2009
    Applicants: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (C.N.R.S.), UNIVERSITAT DE VALENCIA
    Inventors: Azzedine Bousseksou, Gabor Molnar, Saioa Cobo, Lionel Salmon, José Antonio Real Cabezos, Christophe Vieu
  • Patent number: 7611783
    Abstract: A magnetic recording medium includes; a base member; an underlayer formed on the base member; a main recording layer formed on the underlayer, and a writing assist layer formed on or under the main recording layer in contact with the main recording layer. The main recording layer has perpendicular magnetic anisotropy with an anisotropic magnetic field of Hk1 and an inclination of a reversal part of a magnetization curve of a1. The writing assist layer has an anisotropic magnetic field of Hk2 and an inclination of a reversal part of a magnetization curve of a2. The anisotropic magnetic fields Hk1 and Hk2 and the inclinations a1 and a2 satisfy Hk1>Hk2 and a2>a1.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: November 3, 2009
    Assignee: Fujitsu Limited
    Inventors: Ryosaku Inamura, Isatake Kaitsu, Takuya Uzumaki
  • Patent number: 7608348
    Abstract: Magnetic medium for storing information, includes at least two materials A and B which are connected with one another, material A being a hard magnetic material, wherein material B is a material which exhibits metamagnetic behavior in a magnetic field, the metamagnetic behavior of the material being such that, even after passing repeatedly through an external magnetic field from 0 to 10 tesla at least at a magnetic field strength below 3 tesla, an increase in the magnetization occurs as a function of the magnetic field, the increase being superproportional and having a positive curvature.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: October 27, 2009
    Assignee: Leibniz - Institut fuer Festkoerper-und Werkstoffforschung Dresden e.V.
    Inventor: Sebastian Faehler
  • Patent number: 7597972
    Abstract: A magnetic recording medium is provided which has good recording/reproducing characteristics with a recording layer divided in a number of recording elements by a predetermined concavo-convex pattern, and a manufacturing method that enables efficient manufacture of such a magnetic recording medium. The magnetic recording medium includes a substrate, a soft magnetic layer formed over the substrate, a recording layer formed over the soft magnetic layer such as to have magnetic anisotropy in a direction perpendicular to surface, and being divided in a number of recording elements by a predetermined concavo-convex pattern, and a non-magnetic intermediate layer formed between the recording layer and the soft magnetic layer. The recording elements are formed to have a predetermined track shape in a data region.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: October 6, 2009
    Assignee: TDK Corporation
    Inventors: Yoshikazu Soeno, Mitsuru Takai, Katsumichi Tagami, Kazuya Shimakawa
  • Patent number: 7592079
    Abstract: A magnetic disk for information storage that includes a substrate and an information layer for containing information. The information layer includes a upper (e.g., recording) and lower (e.g., stabilizing) layers. The information layer has a remanence-squareness-thickness-product (“Mrt”) that varies radially between first and second disk radii. At least one of the following conditions is true: (i) the information layer has a coercivity that is at least substantially constant between the first and second disk radii; (ii) the lower magnetic layer has a magnetic anisotropy energy of no more than about 1.5×106 erg/cm3; and (iii) the magnetic anisotropy energy of the upper magnetic layer is at least about 150% of the magnetic anisotropy energy of the lower magnetic layer.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: September 22, 2009
    Assignee: Seagate Technology LLC
    Inventors: B. Ramamurthy Acharya, Gunn Choe
  • Publication number: 20090231755
    Abstract: The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.
    Type: Application
    Filed: June 9, 2006
    Publication date: September 17, 2009
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Patent number: 7588841
    Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 may have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAG1 with MAG2. The LCL is located either above or below MAG1 and in direct contact with MAG1 and mediates an effective intergranular exchange coupling in MAG1. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG1, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: September 15, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Andreas Klaus Berger, Eric E. Fullerton, Byron Hassberg Lengsfield, III, David Thomas Margulies
  • Patent number: 7582368
    Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 are either in direct contact with one another or have a coupling layer (CL) located between them. The LCL is located in direct contact with MAG2 and mediates intergranular exchange coupling in MAG2. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG2, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other segregants, which would tend to reduce intergranular exchange coupling in the LCL.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: September 1, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Andreas Klaus Berger, Hoa Van Do, Byron Hassberg Lengsfield, III, Natacha F. Supper
  • Publication number: 20090214895
    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: Application
    Filed: February 18, 2009
    Publication date: August 27, 2009
    Inventors: Tatsuya Hinoue, Hiroshi Kanai, Toshinori Ono, Hiroyuki Suzuki, Hiroshi Inaba
  • Publication number: 20090213494
    Abstract: A perpendicular magnetic recording disk has a soft magnetic underlayer (SUL) that has high corrosion resistance as well as high moment. The material of the SUL is an alloy comprising Co, Fe, X, and Y; where X is Ta or Nb, Y is Zr or Hf, and the combined amount of X and Y present in the alloy is between about 10 and 20 atomic percent. The atomic ratio of Co to Fe in the alloy is between about 90:10 to 10:90, preferably between about 25:75 and 35:65. The SUL may be a single-layer SUL or a multilayer SUL formed of multiple soft magnetic layers separated by an interlayer film or films.
    Type: Application
    Filed: April 27, 2009
    Publication date: August 27, 2009
    Inventors: Qing Dai, Bernd Heinz, Yoshihiro Ikeda, Mary Frances Minardi, Kentaro Takano
  • Patent number: 7579095
    Abstract: 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: Grant
    Filed: April 26, 2007
    Date of Patent: August 25, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Ichihara, Toru Den
  • Publication number: 20090201722
    Abstract: A method for defining magnetic domains in a magnetic thin film on a substrate, includes: coating the magnetic thin film with a resist; patterning the resist, wherein areas of the magnetic thin film are substantially uncovered; and exposing the magnetic thin film to a plasma, wherein plasma ions penetrate the substantially uncovered areas of the magnetic thin film, rendering the substantially uncovered areas non-magnetic.
    Type: Application
    Filed: January 16, 2009
    Publication date: August 13, 2009
    Inventors: Kamesh Giridhar, Omkaram Nalamasu, Steven Verhaverbeke, Mahalingam Venkatesan