Provided is a sputtering target, the sputtering target containing 0.05 at % or more of Bi and having a total content of metal oxides of from 10 vol % to 60 vol %, the balance containing at least Co and Pt.

A glass for magnetic recording medium substrate is an amorphous oxide glass. In terms of mol %, SiO.sub.2 content ranges from 45 to 68%, Al.sub.2O.sub.3 from 5 to 20%, total content of SiO.sub.2 and Al.sub.2O.sub.3 60 to 80%, B.sub.2O.sub.3 from 0 to 5%, MgO from 3 to 28%, CaO from 0 to 18%, total content of BaO and SrO 0 to 2%, total content of alkali earth metal oxides from 12 to 30%, total content of alkali metal oxides from 3.5 to 15%, and at least one kind selected from the group made of Sn oxide and Ce oxide being included, a total content of Sn oxide and Ce oxide ranges from 0.05 to 2.00%, a glass transition temperature ≥625° C., a Young's modulus ≥83 GPa, a specific gravity ≤2.85, and an average linear expansion coefficient at 100 to 300° C.≥48×10.sup.−7/° C.

Provided is a sputtering target containing 0.05 at % or more of Bi, and having a total content of metal oxides of from 10 vol % to 70 vol %, the balance containing at least Ru.

For a further high capacity, provided is a sputtering target for a magnetic recording medium that can form a magnetic thin film having enhanced uniaxial magnetic anisotropy, reduced intergranular exchange coupling, and improved thermal stability and SNR (signal-to-noise ratio).

The sputtering target for a magnetic recording medium, comprises: a metal phase containing Pt and at least one or more selected from Cu and Ni, with the balance being Co and incidental impurities; and an oxide phase containing at least B.sub.2O.sub.3.

A data storage drive includes a magnetic recording media comprising a ferroelectric layer between a bottom electrode layer and a top electrode layer. An applied voltage to the ferroelectric layer generates a strain that is transferred to a ferromagnetic recording layer formed proximate to the ferroelectric layer. The change in strain transferred to the recording layer changes the magnetic properties of the recording layer. A voltage can be selectively applied to all or part of the ferroelectric layer to place the ferromagnetic recording layer in a low coercivity state to assist in writing data. Voltage-assisted magnetic recording (VAMR) is provided based upon control of a magnetic recording media comprising a ferroelectric layer between a bottom electrode layer and a top electrode layer.

A sputtering target according to the present invention contains Co and Pt as metal components, wherein a molar ratio of a content of Pt to a content of Co is from 5/100 to 45/100, and wherein the sputtering target contains Nb.sub.2O.sub.5 as a metal oxide component.

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 a nonmagnetic substrate, a soft magnetic underlayer, an orientation control layer, a perpendicular magnetic layer, and a protection layer that are arranged in this order. The perpendicular magnetic layer includes a first magnetic layer and a second magnetic layer that are arranged in this order on the orientation control layer. The first magnetic layer has a granular structure including an oxide at grain boundary parts of magnetic grains, and the second magnetic layer is closest to the protection layer among layers within the perpendicular magnetic layer, and includes magnetic grains made of a CoCrPt alloy, and a nitride of carbon or a hydride of carbon.

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.

To provide a magnetic recording tape and the like that have excellent magnetic properties and exhibit a favorable SNR. There are provided a magnetic recording tape and the like including at least: a base layer that includes a long film having flexibility; and a magnetic layer formed on a side of one main surface of the base layer, in which an under layer and a seed layer are provided in the stated order from a side of the magnetic layer toward a side of the base layer between the magnetic layer and the base layer, the underlayer contains at least Co and Cr, and has an average atomic number ratio represented by the following formula (1): Co.sub.(100-y)Cr.sub.y (where y is within a range of 37≤y≤45.), and the seed layer formed directly on the base layer has a film thickness of 5 nm or more and 30 nm or less, and contains Ti and O and has an average atomic number ratio represented by the following formula (2): Ti.sub.(100-x)O.sub.x (where x≤10.) or contains Ti—Cr—O and has an average atomic number ratio represented by the following formula (3): (TiCr).sub.(100-x)O.sub.x (where x≤10.).