Abstract: A tape-shaped magnetic recording medium includes a base, a nonmagnetic layer that is provided on the base and contains a nonmagnetic powder, and a magnetic layer that is provided on the nonmagnetic layer and contains a magnetic powder. In the magnetic recording medium, the magnetic layer has an average thickness of not more than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, a coercive force Hc1 in a perpendicular direction is not more than 3,000 Oe, the coercive force Hc1 in the perpendicular direction and a coercive force Hc2 in a longitudinal direction satisfy the relation of Hc2/Hc1?0.8, the nonmagnetic layer has an average thickness of not more than 1.1 ?m, and the nonmagnetic powder has an average particle volume of not more than 2.0×10?5 ?m3.

Abstract: [Object] A cobalt ferrite magnetic powder includes magnetic particles that have a uniaxial crystal magnetic anisotropy and contain cobalt ferrite. A peak top 2? of a (3, 1, 1) plane determined by powder X-ray diffractometry using a CoK? ray is 41.3° or more and 41.5° or less. Some Cos contained in the magnetic particles are substituted with at least one selected from the group consisting of Zn, Ge, and a transition metal element other than Fe.

Abstract: Provided is a magnetic recording medium including: a recording layer containing a powder of particles containing ? iron oxide, in which a ratio ((Hc(50)/Hc(25))×100) of a coercive force Hc(50) measured in a thickness direction of the magnetic recording medium at 50° C. and a coercive force Hc(25) measured in the thickness direction of the magnetic recording medium at 25° C. is 95% or greater, the coercive force Hc(25) is 200 kA/m or greater, and a squareness ratio measured in a transport direction of the magnetic recording medium is 30% or less.

Abstract: A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, and the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1?0.8.

Abstract: A magnetic recording medium used on a record/playback device with a minimum recording wavelength or 50 nm or shorter, the magnetic recording medium including a magnetic layer that contains a spinel-type ferrite magnetic powder, the magnetic layer having an average thickness of 85 nm or smaller, and the magnetic layer having a saturation flux density of 1600 Gauss or larger and 2000 Gauss or smaller.

Abstract: A method of producing a magnetic powder includes performing heat treatment on first particles that contain ferrous oxide to prepare 5 second particles that contain ?-iron oxide.

Abstract: A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1?0.8, and a value of ?1.5??0.5 is not more than 0.6 N in a tensile test of the magnetic recording medium in the longitudinal direction, where ?0.5 is a load at an elongation rate of 0.5% in the magnetic recording medium and ?1.5 is a load at an elongation rate of 1.5% in the magnetic recording medium.

Abstract: A method of producing a magnetic powder includes: performing heat treatment on first particles that contain triiron tetraoxide to prepare second particles that contain ?-iron oxide.

Abstract: [Object] Provided is a technology that is capable of further improving a recording density of data.

Abstract: A magnetic recording medium is used in a recording/reproduction apparatus having a shortest recording wavelength of not more than 75 nm, the magnetic recording medium including a recording layer that contains a powder of particles containing ?-iron oxide, in which a squareness ratio measured in a traveling direction of the magnetic recording medium is not more than 30%, a ratio (Dmax/Dmin) of an average longest diameter Dmax of the particles to an average shortest diameter Dmin of the particles satisfies a relationship of 1.0?(Dmax/Dmin)?1.1, an average thickness ?mag of the recording layer is not more than 100 nm, and a ratio (?mag/Dmin) of the average thickness ?mag of the recording layer to the average shortest diameter Dmin of the particles satisfies a relationship of ?mag/Dmin?5.

Abstract: There is provided a magnetic recording medium which has a layer structure including a magnetic layer and a base layer, and of which an average thickness tT is tT?5.6 ?m, a dimensional change amount ?w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/N??w, a servo pattern is recorded on the magnetic layer, a standard deviation ?PES of a position error signal (PES) value obtained from a servo signal in which the servo pattern is reproduced is ?PES?25 nm, and a maximum value ?1M of a friction coefficient ?1 between a surface on a side of the magnetic layer and an LTO3 head in a case where measurement of the friction coefficient ?1 is performed 250 times is 0.04??1M?0.5.

Abstract: [Solving Means] A method of producing a magnetic powder includes: coating a surface of each of silica-coated precursor particles with at least one type of coating agent of a metal chloride or a sulfate; and firing the precursor particles coated with the coating agent.

Abstract: A tape-shaped magnetic recording medium includes a base, a nonmagnetic layer that is provided on the base and contains a nonmagnetic powder, and a magnetic layer that is provided on the nonmagnetic layer and contains a magnetic powder. In the magnetic recording medium, the magnetic layer has an average thickness of not more than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, a coercive force Hc1 in a perpendicular direction is not more than 3,000 Oe, the coercive force Hc1 in the perpendicular direction and a coercive force Hc2 in a longitudinal direction satisfy the relation of Hc2/Hc1?0.8, the nonmagnetic layer has an average thickness of not more than 1.1 ?m, and the nonmagnetic powder has an average particle volume of not more than 2.0×10?5 ?m3.

Abstract: A magnetic recording medium is provided and includes a layer structure including a magnetic layer, a non-magnetic layer, and a base layer in this order, in which an average thickness tT of the magnetic recording medium is 3.5 ?m?tT?5.3 ?m, a dimensional variation ?w in a width direction of the magnetic recording medium to tension change in a longitudinal direction of the magnetic recording medium is 700 ppm/N??w?2000 ppm/N, and an average thickness tn of the non-magnetic layer is tn?1.0 ?m.

Abstract: A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, and the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1?0.8.

Abstract: [Object] Provided is a technology that is capable of further improving a recording density of data.

Abstract: A magnetic recording medium according to a first technique includes an elongated substrate having a first surface and a second surface, a first reinforcing layer disposed on the first surface, a second reinforcing layer disposed on the second surface, an adhesion suppressing layer disposed on the second reinforcing layer, and a recording layer disposed on the first reinforcing layer or the adhesion suppressing layer.

Abstract: A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1?0.8, and a value of ?1.5??0.5 is not more than 0.6 N in a tensile test of the magnetic recording medium in the longitudinal direction, where ?0.5 is a load at an elongation rate of 0.5% in the magnetic recording medium and ?1.5 is a load at an elongation rate of 1.5% in the magnetic recording medium.

Abstract: A magnetic recording medium includes a nonmagnetic support body, and a magnetic layer containing magnetic powder, in which the magnetic powder contains ?-Fe2O3 crystal (including a case of substituting a portion of Fe site with a metal element M), a product of residual magnetization and a thickness of the magnetic layer is from 0.5 mA to 6.0 mA, and a squareness ratio which is measured in a longitudinal direction of the magnetic layer is 0.3 or less.

Abstract: A magnetic recording medium includes a layer structure including a magnetic layer, a non-magnetic layer, and a base layer in this order, in which an average thickness tT is tT?5.5 ?m, a dimensional variation ?w in a width direction to tension change in a longitudinal direction is 660 ppm/N??w, and an average thickness tn of the non-magnetic layer is tn?1.0 ?m.