Abstract: An example article includes a composite free layer and a conductive channel. The composite free layer includes a high-anisotropy ferromagnetic layer, a non-magnetic transition metal layer adjacent to the high anisotropy ferromagnetic layer, and an ultra-low damping magnetic insulator. The non-magnetic transition metal layer is between the ultra-low damping magnetic insulator and the high-anisotropy ferromagnetic layer. An example spin-orbit torque (SOT) stack may include the example article. Techniques for forming and switching example articles and SOT stacks are described.
Abstract: In one embodiment, a magnetic media suitable for HAMR recording includes a recording layer having first and second magnetic layers. The first magnetic layer has a first segregant between magnetic grains thereof, the first segregant being primarily C. Moreover, the second magnetic layer is formed above the first magnetic layer. The second magnetic layer has a second segregant between magnetic grains thereof, the second segregant being primarily C and a second component. Additional systems and methods are also described herein.
Type:
Application
Filed:
November 19, 2013
Publication date:
May 21, 2015
Applicant:
HGST Netherlands B.V.
Inventors:
Olav Hellwig, Oleksandr Mosendz, Simone Pisana, Dieter K. Weller
Abstract: The magnetic recording medium is a particulate magnetic recording medium for heat-assisted recording, as well as includes a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic organic material support and a heat-diffusing layer of higher thermal conductivity than the magnetic layer between the nonmagnetic organic material support and the magnetic layer.
Abstract: A recording method for irradiating a multi-layered optical recording medium with a laser beam to record information thereon. The optical recording medium can form a first information recording layer that is the farthest from a light incident surface, a second information recording layer that is the second farthest from the light incident surface, and at least one third information recording layer that is located closer to the light incident surface than the second information recording layer is. The method is to record information on the second information recording layer when all the information recording layers other than the second information recording layer are either blank or have been completely recorded. This allows for realizing high-quality information recording in consideration of adherence of foreign matters or occurrence of scratches.
Abstract: A portable card adapted to interact with a data processing station when the portable card and the data processing station are moved relative to each other is disclosed. The portable card includes a substrate having a predetermined shape, e.g. rectangular. An accessible embedded storage member is enclosed within said substrate. The storage member includes at least one layer of storage material for storing information in a predetermined format for processing by the data processing station. The storage member and the substrate are adapted to be transported relative to each other to expose at least a portion of the storage member to the data processing station to facilitate processing of stored information and for embedment of the storage member within the substrate. The storage member may be in the form of an elongated strip member, or a circular member.
Abstract: A portable card adapted to interact with a data processing station when the portable card and the data processing station are moved relative to each other is disclosed. The portable card includes a substrate having a predetermined shape, e.g. rectangular. An accessible embedded storage member is enclosed within said substrate. The storage member includes at least one layer of storage material for storing information in a predetermined format for processing by the data processing station. The storage member and the substrate are adapted to be transported relative to each other to expose at least a portion of the storage member to the data processing station to facilitate processing of stored information and for embedment of the storage member within the substrate. The storage member may be in the form of an elongated strip member, or a circular member.
Abstract: Provided are a magnetic track using magnetic domain wall movement and an information storage device including the same. A magnetic track may comprise a zigzag shaped storage track including a plurality of first magnetic layers in parallel with each other, and stacked separate from each other, and a plurality of second magnetic layers for connecting the plurality of first magnetic layers. The information storage device may include the magnetic track having a plurality of magnetic domains, current applying device connected to the magnetic track, and a read/write device on a middle portion of the magnetic track.
Type:
Application
Filed:
February 29, 2008
Publication date:
February 12, 2009
Inventors:
Kwang-seok Kim, Sung-chul Lee, Sun-ae Seo
Abstract: A magnetic head for a magneto-optical device comprises a plurality of substantially parallel planar layers, including at least one layer comprising a coil formed by a plurality of turns an electrically conductive winding, the turns lying substantially in a plane defined by the layer and the winding being substantially centered on a central axis perpendicular to the plane, and further including a yoke layer comprised of an anisotropic flux guiding material. The yoke layer comprises a plurality of segments (16) of flux guiding material dividing the yoke layer into sectors that together surround the central axis. In each sector, the flux guiding material has an easy axis in a plane of the yoke layer with a direction different from the direction of the easy axis in an adjacent sector.
Type:
Application
Filed:
July 30, 2004
Publication date:
October 2, 2008
Inventors:
Hans Willem Van Kesteren, Rudolf Johan Maria Vullers
Abstract: A method for manufacturing a magneto-optical recording medium in which reading of recorded information is performed through domain wall displacement in a reproduction layer is provided, in which magnetic separation of groove side-wall portions is performed more reliably; as a result a magneto-optical recording medium with satisfactory recording and reproduction characteristics can be provided.
Abstract: The present invention provides a magneto-optical recording medium including a recording layer, an intermediate layer and a reproducing layer stacked in this order. Information recorded in the recording layer is transferred to the reproducing layer through the intermediate layer so that the information is reproduced. The reproducing layer includes an upper reproducing layer, a coupling layer, and a lower reproducing layer formed in this order on the intermediate layer. Magnetic information in the upper reproducing layer in an area whose temperature is increased to a predetermined temperature is transferred to the lower reproducing layer through the coupling layer.
Type:
Grant
Filed:
August 25, 2004
Date of Patent:
January 16, 2007
Assignee:
Fujitsu Limited
Inventors:
Ryo Kurita, Ken Tamanoi, Shoyu Ito, Motonobu Mihara
Abstract: A perpendicular magnetic recording medium has a substrate, a magnetic functional layer provided on the substrate, and a magnetic recording layer stacked in contact with the magnetic functional layer and having perpendicular magnetic anisotropy. ?4×2?Ms2?Ku?6×2?Ms2 is satisfied, wherein Ku represents a perpendicular magnetic anisotropy constant of the magnetic functional layer and Ms represents a saturation magnetization. The magnetic moment of the magnetic functional layer is rotated in a direction of an applied magnetic field during the recording, and the magnetic moment acts on the magnetization of the recording layer in such a manner that the applied magnetic field is assisted thereby. Minute magnetic domains can be stably retained and excellent thermal disturbance resistance can be obtained.
Type:
Grant
Filed:
December 30, 2003
Date of Patent:
May 2, 2006
Assignee:
Hitachi Maxell, Ltd.
Inventors:
Katsusuke Shimazaki, Satoshi Matsunuma, Teruaki Takeuchi, Norio Ota
Abstract: An optical information recording medium for recording information by a plurality of record mark lengths, wherein the shortest mark length is at most 0.5 ?m, and a crystal state is an unrecorded or erased state and an amorphous state is a recorded state, wherein the erasing is carried out by recrystallization which substantially proceeds by crystal growth from an interface between the amorphous portion or a melt portion and a peripheral crystal portion; and an optical recording method suitable therefore. The medium of the present invention has characteristics that overwriting can be made at a high speed, the jitter of mark edge is small, mark length modulation recording can be made at a high density, and the formed mark is excellent in the stability with the lapse of time.
Abstract: The evaluation reference tape includes at least one recess formed on a magnetic recording layer of a magnetic tape by processing the magnetic recording layer. In the method and apparatus for manufacturing the magnetic recording layer, at least one recess is formed on the magnetic recording layer of the magnetic tape by a laser beam or laser beams in a visible region, an ultraviolet region or both which is incident on the magnetic recording layer of the magnetic tape while the magnetic tape is transported in the longitudinal direction. The evaluation reference tape can perform sensitivity correction of a dropout testing apparatus in accordance with a depth or size of a defect of the magnetic tape and evaluation of the recording/replaying system of the magnetic tape without destroying the evaluation reference tape itself. The method and apparatus can efficiently manufacture the evaluation reference tape.
Abstract: A magneto-optical recording medium has a configuration such that information recorded can be read from a region smaller than a beam spot by applying an external magnetic field and directing a light beam in reproducing. The magneto-optical recording medium includes a magnetic recording layer for recording and holding information, a magnetic reproducing layer provided on one side of the magnetic recording layer on which the light beam is incident, a nonmagnetic layer provided on another side of the magnetic recording layer opposite to the magnetic reproducing layer, and a magnetic assist layer provided on the nonmagnetic layer. The magnetic assist layer has a coercive force smaller than an external magnetic field applied in recording or reproducing information.
Abstract: An optical recording medium has spirally or concentrically formed tracks and is capable of an optical recording. The optical recording medium includes a data recording and reproducing area divided into a plurality of zones in the radial direction. One zone is divided into a plurality of sectors respectively having an address part including pits having address information and a data part only composed of grooves. The number of sectors forming each zone is different. An optical disc is formed so that an average reflectance Iadd of the address part and an average reflectance Idata of the data part satisfy a relation expressed by 0.7≦(Iadd/Idata)≦1.3 or 0.8≦(Iadd/Idata)≦1.2.
Abstract: A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.
Type:
Grant
Filed:
December 5, 2001
Date of Patent:
August 3, 2004
Assignee:
Fujitsu Limited
Inventors:
Tsutomu Tanaka, Motonobu Mihara, Ken Tamanoi
Abstract: A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.
Abstract: An information recording medium comprising an information recording film formed on a base on which regular depressions and projections having Ra of 0.1 to 1.5 nm have been formed, the information recording film containing as a major component a rare earth-transition metal amorphous alloy capable of magnetically reproducing a recorded information.
Abstract: A magnetic recording medium includes: a disk substrate; and a recording layer having magnetic anisotropy along a direction perpendicular to a surface of the disk substrate. The recording layer is formed so that a product of a coercive force Hc and saturated magnetization Ms of the recording layer (Ms·Hc) at room temperatures is increased sufficiently so that a shortest mark length of the recording layer can be decreased to a desired value.
Type:
Application
Filed:
September 18, 2003
Publication date:
March 25, 2004
Applicant:
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Abstract: Featured is a recording and reproducing method of a magneto-optical recording medium including a recording layer for recording thereon information magneto-optically and a readout layer which has in-plane magnetization at room temperature and where a transition occurs from in-plane magnetization to perpendicular magnetization as temperature raises. The method includes projecting a light beam onto such a magneto-optical recording medium so as to form a perpendicularly magnetized area in the readout layer by duplication of the magnetization of said recording layer to the area. In further embodiments, the recording medium further includes an intermediate layer made of non-magnetic film formed between the readout and recording layers and the readout and recording layers are composed of rare-earth transition metal alloys such as TbFeCo (recoding layer) readout layer, made of GdFeCo (readout layer).
Abstract: A magneto-optical recording medium includes a magnetic reproducing layer having an axis of easy magnetization in a direction perpendicular to its layer surface, a magnetic intermediate layer formed on the magnetic reproducing layer and having an axis of easy magnetization in a plane at a room temperature, and a magnetic recording layer formed on the magnetic intermediate layer and having an axis of easy magnetization in a direction perpendicular to its layer surface. The magnetic reproducing layer has a composition of GdxFeCoy where 22 at %≦x≦25 at % and 16 at %≦y≦23 at %.
Abstract: A magneto-optical recording medium has magneto-optical recording layers (11, 12, 13) and reproducing layers (21, 22, 23). The information recorded in the reproducing layers are reproduced by means of reproducing light beams (31, 32, 33) of different wavelengths, respectively. In reproduction, magnetic domains (4) recorded in the recording layers are transferred in the reproducing layers formed on the respective recording layers, the transferred magnetic domains (5) are enlarged with an external magnetic field, and the information is reproduced. Since information is recorded and reproduced for each recording layer, the recording density is improved. Further since the reproduction signals are amplified by the magnetic domain enlargement, the C/N is improved.
Abstract: At least a reproduction layer of a magneto-optical recording medium is formed by sputtering using a processing gas comprising Kr or Xe as a main component. Hence, it is possible to reduce the dependence of saturation magnetization MS on temperature, thereby decreasing the influence of a demagnetizing field and a floating magnetic field over a wide range of temperature.
Abstract: A magneto-optical recording medium includes a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.
Abstract: In order to provide a magneto-optical recording medium which can select a single recording magnetic domain in the recording layer accurately and expand and transfer the same to the reproducing layer, the magneto-optical recording medium is arranged in the following manner. That is, the magnetization direction of the reproducing layer is in-plane at room temperature and shifts to perpendicular at or above a predetermined temperature Ttrans.. The recording layer is a magnetic layer which is magneto-statically coupled to the reproducing layer and shows the perpendicular magnetization up to its Curie temperature. The magnetic mask layer is provided between the recording layer and reproducing layer, and the magnetization thereof is reduced to 0 (zero) at or above a predetermined temperature (Tm) which is at or above Ttrans.. The magnetization of the magnetic mask layer is larger than that of the recording layer at least in a range between room temperature and Ttrans..
Type:
Grant
Filed:
November 30, 1999
Date of Patent:
November 5, 2002
Assignee:
Sharp Kabushiki Kaisha
Inventors:
Naoyasu Iketani, Go Mori, Michinobu Mieda, Akira Takahashi
Abstract: Patterned magnetic media are provided at high resolution and pattern definition by a process comprising steps of: applying to a magnetic layer a first uniform magnetic field of a first direction and strength to pre-align the magnetic grains thereof; applying a second uniform magnetic field of a second, opposite direction and of lesser strength than the first magnetic field, sufficient to change the alignment of the magnetic grains only when the temperature thereof is equal to or greater than the Curie temperature Tc; selectively increasing the temperature of a pattern of selected surface areas of the magnetic layer to at least Tc for an interval while applying the second magnetic field to thereby selectively change the alignment of the magnetic grains of the selectively heated surface areas; terminating application of the second magnetic field after completion of the selective realignment; and cooling the selectively heated surface areas to a temperature below Tc, whereby the magnetic pattern is preserved in