A magnetic recording medium includes a substrate, an underlayer formed on the substrate, and a magnetic layer formed on the underlayer. The magnetic layer includes an alloy having a L1.sub.0 structure. The underlayer includes a first underlayer and a second underlayer. The first underlayer includes Mo and Ru, the content of Ru in the first underlayer is in a range of 5 atom % to 30 atom %, and the second underlayer includes a material having a body-centered cubic (BCC) structure. The second underlayer is formed between the first underlayer and the substrate.

A magnetic tape in which a tape thickness of the magnetic tape is 5.2 m or less, and in an environment with a temperature of 32 C. and a relative humidity of 80%, a frictional force F.sub.45 on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45 is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0, 15, 30, and 45 is 10 gf or less.

A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer that are arranged in this order. The magnetic layer has a granular structure including magnetic grains having a L1.sub.0 crystal structure, and grain boundary parts having a volume fraction in a range of 25 volume % to 50 volume %. The magnetic grains have a c-axis orientation with respect to the substrate. The grain boundary parts include a material having a lattice constant in a range of 0.30 nm to 0.36 nm, or in a range of 0.60 nm to 0.72 nm.

A magnetic recording medium includes: an elongated substrate having flexibility; a first layer, being provided on the substrate, containing Cr, Ni, and Fe, and having a face-centered cubic lattice structure with a (111) plane preferentially oriented so as to be parallel to a surface of the substrate; a second layer, being provided on the first layer, containing Co and O, having a ratio of an average atomic concentration of O to an average atomic concentration of Co of 1 or more, and having a column structure with an average particle diameter of 3 nm or more and 13 nm or less; a third layer, being provided on the second layer, and containing Ru; and a perpendicular recording layer, being provided on the third layer.

Provided is an FePt based magnetic material sintered compact, comprising BN and SiO.sub.2 as non-magnetic materials, wherein Si and O are present in a region where B or N is present at a cut surface of the sintered compact. An object of the present invention is to provide a high density sputtering target which enables production of a magnetic thin film for heat-assisted magnetic recording media, and also reduces the amount of particles generated during sputtering.

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/Hc10.8, and a value of 1.50.5 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.

A heat-assisted magnetic recording (HAMR) medium has a heat-sink layer, a chemically-ordered FePt (or CoPt) alloy magnetic layer and a MgNiO intermediate layer between the heat-sink layer and the magnetic layer. The intermediate layer is a solid substitution crystalline alloy of the form (Mg.sub.(100-y)Ni.sub.y)O, where y is less than 10 and greater than or equal to 0.5. The magnetic layer may be formed directly on the MgNiO intermediate layer, in which case the MgNiO intermediate layer functions as both a seed layer and a thermal barrier layer. The HAMR medium may also include an optional layer of crystalline pure MgO directly below or directly above the MgNiO intermediate layer. If the MgO layer is located directly above the MgNiO intermediate layer then the MgNiO intermediate layer functions primarily as a thermal barrier layer. The HAMR medium with the MgNiO intermediate layer provides a substantial improvement in corrosion resistance.

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/Hc10.8, 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.

A sputtering target for magnetic recording media capable of producing a magnetic thin film in which the magnetic crystal grains are micronized and the distance between the centers of the grains is reduced while good magnetic properties are maintained. The target including metallic Pt and an oxide, with the balance being metallic Co and inevitable impurities, wherein the Co is contained in a range of 70 at % to 90 at % and the Pt is contained in a range of 10 at % to 30 at % relative to a total of metallic components in the sputtering target for magnetic recording media, the oxide is contained in a range of 26 vol % to 40 vol % relative to a total volume of the sputtering target for magnetic recording media, and the oxide is composed of B.sub.2O.sub.3 and one or more high-melting-point oxides having a melting point of 1470 C. or higher and 2800 C. or lower.

Provided is a magnetic recording medium having a recording track width of 2 m or less, including: a recording layer containing a powder of particles containing 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 S1S2, 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.