Abstract: Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.
Abstract: The present invention aims to provide a rare earth magnet having sufficiently excellent anticorrosion property. The rare earth magnet 1 according to the present invention to solve the above problems includes a magnet body 10 containing rare earth elements, a substantial amorphous layer 20 formed on a surface of the magnet body 10, and a protecting layer 30 on a surface of the amorphous layer 20, and the amorphous layer 20 contains material identical to main component elements of magnet material contained in the magnet body 10.
Abstract: Provided is a magnetic disk comprising a lubricating layer formed of a lubricant. The lubricant constituting the lubricating layer has excellent properties, for example, excellent fluidity, surface energy, and CFT properties. By virtue of the excellent properties, the magnetic disk has a high level of reliability despite a low flying height of a magnetic head due to a recent rapid increase in recording density and a very severe environment resistance requirement due to diversification of applications. The magnetic disk comprises a substrate and at least a magnetic layer, a protective layer, and a lubricating layer provided in that order over the substrate.
Abstract: A lubricant for a magnetic disk that is excellent in heat resistance and is suitably used in a magnetic disk to be mounted on a magnetic recording device of a thermally assisted magnetic recording system and a magnetic disk provided with a lubricant layer containing this lubricant. The lubricant for a magnetic disk contains a compound where perfluoropolyether groups each having a perfluoropolyether main chain in its structure and a phosphazene ring at an end are linked to each other through a linking group. The linking group is an aliphatic group or a phosphazene ring. In a magnetic disk having at least a magnetic recording layer, a protective layer, and a lubricant layer on a substrate, the lubricant layer contains the lubricant for a magnetic disk.
Abstract: A perpendicular magnetic recording (PMR) media including a non-magnetic or superparamagnetic grain isolation magnetic anisotropy layer (GIMAL) to provide a template for initially well-isolated small grain microstructure as well as improvement of Ku in core grains of a magnetic recording layer. The GIMAL composition may be adjusted to have lattice parameters similar to a bottom magnetic recording layer and to provide a buffer for reducing interface strains caused by lattice mismatch between the bottom magnetic recording layer and an underlying layer.
Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.
Type:
Grant
Filed:
June 29, 2012
Date of Patent:
March 31, 2015
Assignee:
Western Digital Technologies, Inc.
Inventors:
Bollapragada Varaprasad, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov
Abstract: A lubricant containing a compound (A) comprising a perfluoropolyether having a main-chain structure of the formula (1) and having a polar group at each of opposite terminals thereof, and a compound (B) comprising a perfluoropolyether having a main-chain structure of the formula (1) and having a nonpolar group at at least one terminal thereof —(CF2CF2CF2O)a-??(1) wherein a is a real number of 5 to 30.
Abstract: A magnetic recording medium includes a nonmagnetic substrate provided on which are, in the order recited; an underlayer; a magnetic layer; a protective layer comprised of carbon; and a lubricating layer composed of a lubricant mixture composed of a lubricant represented by Formula (I) below where m is an integer equal to or greater than 1, and R1 and R2 are divalent straight chains consisting of both —CH2 CF2 — or both —CH2 CF2CF2—; and a lubricant represented by Formula (II) below where p and q are integers equal to or greater than 0, provided that p =q =0 is excluded. A method of manufacturing the magnetic recording medium is likewise disclosed.
Abstract: A magnetic recording medium includes a substrate; a metal film layer disposed on the substrate; a protective film disposed on the metal film layer; and a lubricant film disposed on a surface of the protective film. The protective film is composed of amorphous carbon containing fluorine and nitrogen in a surface region, and a region deeper than 0.5 nm deep from the surface of the protective film is substantially free from the fluorine and nitrogen. The fluorine and nitrogen may be each added in an amount of 5 to 20 at. %. The present invention simultaneously accomplishes a reduction in film thickness, an improvement in durability and corrosion resistance, and an improvement of the bonding strength of the surface of the protective film to the lubricating film.
Abstract: A thin film magnetic head includes a magnetoresistive effect (MR) laminated body that has the following structure: first and second magnetic layers in which the magnetization direction of at least one of the magnetic layers changes according to an external magnetic field; the first magnetic layer is provided at a lower side of a laminated direction; the second magnetic layer is provided at an upper side of the laminated direction; a non-magnetic intermediate layer made of ZnO sandwiched between the first and the second magnetic layers; a first intermediate interface layer is provided at the interface between the first magnetic layer and the non-magnetic intermediate layer; and a second intermediate interface layer is provided at the interface between the non-magnetic intermediate layer and the second magnetic layer. At least the first intermediate interface layer contains Ag and Zn, or Au and Zn.
Abstract: Media may be produced with narrow c-axis dispersion while having small grain size and high grain density. A dual seed layer design and a substrate bias voltage may be applied during deposition of the seed layer are used in the media. In some embodiments, the first seed layer is an amorphous material because of a high content of elements with large atomic sizes. Application of the substrate bias during deposition of the second seed layer may reduce the grain size and may narrow c-axis dispersion.
Type:
Grant
Filed:
June 30, 2011
Date of Patent:
February 17, 2015
Assignee:
WD Media, LLC
Inventors:
Tuqiang Li, Donald C. Stafford, Sudhir S. Malhotra, Tsutomu T. Yamashita
Abstract: [Problem] A perpendicular magnetic disk with an improved SNR and increased recording density by further advancing microfabrication and uniformalization of particle diameters and improving crystal orientation regarding a preliminary ground layer made of a Ni-base alloy is provided. [Solution] The perpendicular magnetic disk includes: on a base 110, a first Ni alloy layer 142 and a second Ni alloy layer 144; a ground layer 150 having Ru as a main component; and a perpendicular magnetic recording layer 160 containing a CoPt-base alloy and an oxide in this order, the first Ni alloy layer 142 and the second Ni alloy layer 144 including at least one element that takes a bcc crystal structure as a simple substance, and the second Ni alloy layer 144 further including an oxide.
Abstract: A recording medium comprising a magnetic recording layer having an axis of magnetic anisotropy substantially perpendicular to the surface thereof, a soft magnetic underlayer disposed under the magnetic recording layer and physically coupled to the magnetic recording layer through one or more intermediate layers magnetically decoupling the soft magnetic underlayer from the magnetic recording layer, and an orientation initialization layer disposed between the magnetic recording layer and the soft magnetic underlayer.
Type:
Grant
Filed:
August 5, 2010
Date of Patent:
February 3, 2015
Assignee:
WD Media, LLC
Inventors:
Hua Yuan, Alexander Chernyshov, B. Ramamurthy Acharya
Abstract: A magnetic recording medium in which information can be recorded using a heat-assisted magnetic recording method comprises a recording layer formed on a substrate. The recording layer has a plurality of magnetic recording bit regions and a plurality of high thermal conductors each extending inside a corresponding one of the bit regions. The high thermal conductors have a thermal conductivity higher than that of the recording layer and assist in dissipating heat energy imparted to the bit regions during the recording of information.
Abstract: A cyclophosphazene compound of the formula (I), and lubricants and magnetic disks using the compound wherein n is 2, 3 or 4, m is an integer of 1 to 12, R is C1-4 fluoroalkyl and Rf is —CF2O(CF2CF2O)x(CF2O)yCF2— or —CF2CF2O(CF2CF2CF2O)zCF2CF2— in which x, y and z are each 0 or a positive real number to give a number average molecular weight of 500 to 4000 to a fluoropolyether of the formula HOCH2—Rf—CH2OH including said Rf, the fluoropolyether having a molecular weight distribution (PD) of 1.0 to 1.5.
Abstract: According to one embodiment, a patterned magnetic storage medium is disclosed herein. The magnetic storage medium includes a pattern formed on a substrate. The pattern includes at least a first and second feature and an edge defined between the first and second features. Additionally, the magnetic storage medium includes a magnetic layer formed on the pattern. The magnetic layer includes grains separated by a non-magnetic segregant boundary. The segregant boundary is positioned above the edge of the pattern.
Type:
Grant
Filed:
December 31, 2011
Date of Patent:
December 30, 2014
Assignee:
HGST Netherlands B.V.
Inventors:
Liesl Folks, Michael K. Grobis, Dan S. Kercher, Ricardo Ruiz, Kentaro Takano, Bruce D. Terris, Qing Zhu
Abstract: Magnetic memories and methods are disclosed. A magnetic memory as described herein includes a plurality of stacked data storage layers to form a three-dimensional magnetic memory. The data storage layers are each formed from a multi-layer structure. At ambient temperatures, the multi-layer structures exhibit an antiparallel coupling state with a near zero net magnetic moment. At higher transition temperatures, the multi-layer structures transition from the antiparallel coupling state to a parallel coupling state with a net magnetic moment. At yet higher temperatures, the multi-layer structure transitions from the antiparallel coupling state to a receiving state where the coercivity of the multi-layer structures drops below a particular level so that magnetic fields from write elements or neighboring data storage layers may imprint data into the data storage layer.
Type:
Grant
Filed:
December 16, 2007
Date of Patent:
December 16, 2014
Assignee:
HGST Netherlands B.V.
Inventors:
Olav Hellwig, Bruce D. Terris, Jan-Ulrich Thiele
Abstract: A magnetic data storage medium comprising: an ion doped magnetic recording layer having a continuous grading of coercivity or anisotropy, wherein the coercivity or anisotropy is at a minimum substantially at one side of the magnetic recording layer, and having substantial portion of maximum coercivity or anisotropy at the other side of the magnetic recording layer. Also, a method of fabricating a magnetic data storage medium is included.
Type:
Grant
Filed:
January 31, 2012
Date of Patent:
December 2, 2014
Assignee:
International Business Machines Corporation
Inventors:
Charanjit Singh Bhatia, Koashal Kishor Mani Pandey, Nikita Gaur, Siegfried L. Maurer, Ronald W. Nunes
Abstract: In a perpendicular magnetic recording medium having, over a substrate, a magnetic recording layer, an underlayer made of Ru or a Ru compound and provided below the magnetic recording layer, a pre-underlayer made of a nonmagnetic crystalline material, and a soft magnetic layer provided below the pre-underlayer, when the difference between the highest point and the lowest point of unevenness of the interface between the soft magnetic layer and the pre-underlayer, derived by a cross-sectional TEM image, is given as an interface roughness (nm) and the distance between the soft magnetic layer and the magnetic recording layer, excluding the soft magnetic layer and the magnetic recording layer, is given as a SUL-MAG distance (nm), interface roughness (nm)?0.4 (nm) and interface roughness×SUL-MAG distance (nm)?12 (nm) are satisfied.
Abstract: A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate. The SUL has a plurality of SUL layers including a type-A SUL layer, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb.