Patent classifications
G11B5/65
MAGNETIC RECORDING MEDIUM AND MAGNETIC STORAGE APPARATUS
A magnetic recording medium includes a substrate, an underlayer disposed above the substrate, and a first magnetic layer disposed above the underlayer. The first magnetic layer has a granular structure including magnetic grains having a L1.sub.0 structure, and grain boundaries. A content of the grain boundaries is in a range of 25 volume percent to 50 volume percent, and the grain boundaries include a chalcogenide-based layered material.
MAGNETIC POWDER, MANUFACTURING METHOD OF MAGNETIC POWDER, AND MAGNETIC RECORDING MEDIUM
Magnetic powder includes: an epsilon-phase iron oxide-based compound selected from ε-Fe.sub.2O.sub.3 or a compound represented by Formula (1). The magnetic powder has an average particle diameter of 8 nm to 25 nm, a ratio of Hc to Hc′ of from 0.6 to 1.0, and Hc′ satisfying Expression (II). Hc′ represents a magnetic field at which a value of Expression (I) becomes zeroin a magnetic field-magnetization curve obtained by performing measurement at a maximum applied magnetic field of 359 kA/m, a temperature of 296 K, and a magnetic field sweeping speed of 1.994 kA/m/s. M represents magnetization and H represents applied magnetic field. Hc represents a magnetic field at which magnetization becomes zero in the magnetic field-magnetization curve. In Formula (1), A represents at least one metal element other than Fe, and a represents a number that satisfies a relationship of 0<a<2.
d.sup.2M/dH.sup.2 Expression (I)
119 kA/m<Hc′<2380 kA/m Expression (II)
ε-A.sub.xFe.sub.2-xO.sub.3 (1)
Process for forming magnetic recording layer for tape media
A method, in one approach, includes forming a magnetic recording layer having: encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an encapsulating layer, and a polymeric binder binding the encapsulated nanoparticles.
Process for forming magnetic recording layer for tape media
A method, in one approach, includes forming a magnetic recording layer having: encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an encapsulating layer, and a polymeric binder binding the encapsulated nanoparticles.
Magnetic stack including non-magnetic seed layer for hard disk drive media
A magnetic stack includes a substrate and a soft magnetic underlayer deposited on a top surface of the substrate. A heat sink layer is disposed on top of the soft magnetic underlayer, and an interlayer is deposited on top of the heat sink layer. A non-magnetic seed layer is deposited on top of the interlayer. A magnetic recording structure which includes more than one magnetic recording layer is deposited on the top surface of the non-magnetic seed layer.
Magnetic stack including non-magnetic seed layer for hard disk drive media
A magnetic stack includes a substrate and a soft magnetic underlayer deposited on a top surface of the substrate. A heat sink layer is disposed on top of the soft magnetic underlayer, and an interlayer is deposited on top of the heat sink layer. A non-magnetic seed layer is deposited on top of the interlayer. A magnetic recording structure which includes more than one magnetic recording layer is deposited on the top surface of the non-magnetic seed layer.
MAGNETIC RECORDING TAPE AND APPARATUS
A magnetic recording tape comprises a tape substrate, a perpendicular magnetic recording layer disposed over the tape substrate, and a soft-magnetic underlayer disposed between the recording layer and the tape substrate. The perpendicular magnetic recording layer comprises magnetic particles suspended in a binder material, and the soft-magnetic underlayer comprises a continuous film of soft-magnetic material. The magnetic particles in the recording layer comprise one of barium ferrite, strontium ferrite, epsilon iron oxide and chromium dioxide. Tape storage apparatus employing such tape is also provided. The apparatus comprises a read/write head having at least one probe write-head for writing data by perpendicular recording on magnetic tape, at least one reel of magnetic tape as defined above, and a tape transport mechanism for transporting the magnetic tape past the read/write head.
Magnetic recording medium
Provided is a magnetic recording medium having a recording track width of 2 μm or less, including: a recording layer containing a powder of particles containing ε iron oxide, in which a squareness ratio measured in a transport direction is 30% or less, a squareness ratio S1 measured in the transport direction and a squareness ratio S2 measured in a width direction satisfy a relationship S1≥S2, a coercive force is 220 kA/m or greater and 310 kA/m or less, an activation volume is 8000 nm.sup.3 or less, and in a switching field distribution (SFD) curve, a peak ratio X/Y of a main peak height X and a height Y of a sub-peak near zero magnetic field is 3.0 or greater.
Magnetic recording medium, magnetic storage apparatus, and method for manufacturing magnetic recording medium
A magnetic recording medium includes a substrate, and a magnetic recording layer including magnetic grains having an L1.sub.0 structure. The magnetic recording layer is (001) oriented, and a surface of growth of the magnetic recording layer includes a (001) plane, a (111) plane, and planes equivalent to the (111) plane. An area ratio of the (111) plane and the planes equivalent to the (111) plane, represented by (A.sub.111+A.sub.111e)/(A.sub.001+A.sub.111+A.sub.111e), is in a range of 0.2 to 0.7, where A.sub.111 denotes an area of the (111) plane, A.sub.111e denotes an area of the planes equivalent to the (111) plane, and A.sub.001 denotes an area of the (001) plane.
Magnetic recording medium and method of producing the same
There is provided a magnetic recording medium including a base; a seed layer; a foundation layer; and a recording layer, the seed layer being disposed between the base and the foundation layer, having an amorphous state, including an alloy containing Ti, Cr and O, a percentage of Ti being 30 atomic % to 100 atomic % based on a total amount of Ti and Cr contained in the seed layer, and a percentage of O being 15 atomic % or less based on a total amount of Ti, Cr and O contained in the seed layer. Also, a production method thereof is provided.