The present invention is a method for mass-production of a recording medium with the component composition thereof monotonically changing along the film thickness direction. In the method, the magnetic recording medium that includes at least a substrate, and first magnetic recording layer and second magnetic recording layer as the magnetic recording layer. The method includes: laminating a second magnetic layer of FePtRh on a first magnetic layer of FePt or FePtRh with heating. In the method, heat treatment may be preheat-treatment or postheat-treatment, when laminating the second magnetic layer of FePtRh onto the first magnetic layer of FePtRh, the concentration of Rh in the second magnetic layer is higher than that of the first magnetic layer.

The present invention aims at providing a magnetic recording medium capable of realizing lowering of recording temperature. A magnetic recording medium comprises a substrate, and a magnetic recording layer comprising a first magnetic layer and a second magnetic layer, in which the second magnetic layer comprises an FePtRh ordered alloy, and the first magnetic layer has Ku at room temperature larger than Ku of the second magnetic layer at room temperature.

A stack includes a substrate, a magnetic recording layer having a columnar structure, and an interlayer disposed between the substrate and the magnetic recording layer. The columnar structure includes magnetic grains separated by a crystalline segregant or a combination of crystalline and amorphous segregants.

An e-type iron-based oxide magnetic particle powder has narrow particle size distribution and has a low content of fine particles which do not contribute to magnetic recording characteristics. As a result, a narrow coercive force distribution is achieved and the powder is suitable for increasing recording density of a magnetic recording medium. The powder containing substituting metal elements can be obtained by: adding an alkali to an aqueous solution containing trivalent iron ions and ions of the metals for partially substituting Fe sites to neutralize the aqueous solution to a pH of 1.5 to 2.5; then adding a hydroxycarboxylic acid; further adding the alkali to neutralize the aqueous solution to a pH of 8.0 to 9.0; washing with water a precipitation of an iron oxyhydroxide containing the substituting metal elements produced; and coating the iron oxyhydroxide containing the substituting metal elements with a silicon oxide and heating the resultant.

The hexagonal ferrite powder has an activation volume of greater than or equal to 800 nm.sup.3 but less than 1,200 nm.sup.3, a rare earth atom content falling within a range of 0.5 to 8.0 atom % per 100 atom % of iron atoms, and a localized presence of rare earth atoms in the surface layer portion, as well as is in the form of ellipsoidal powder.

A stack includes a substrate, a magnetic recording layer comprising FePtX disposed over the substrate, and a capping layer disposed on the magnetic recording layer. The capping layer comprises Co; at least one rare earth element; one or more elements selected from a group consisting of Fe and Pt; and an amorphizing agent comprising one to three elements selected from a group consisting of B, Zr, Ta, Cr, Nb, W, V, and Mo.

Magnetic recording media including an interlayer configured to reduce lattice mismatch with adjacent layers of the media, such as an adjacent seed layer or an adjacent underlayer. In one example, an interlayer alloy is provided that includes tungsten (W) along with Cobalt (Co), Chromium (Cr), and Ruthenium (Ru). The atomic percentages of W and Ru within the interlayer are selected so that the amount lattice mismatch between the interlayer and its adjacent layers is below a preselected amount, such as below 3% as quantified by d-spacing. In some examples, the atomic percentage of Ru is greater than 25% and the atomic percentage of W is 2-10%. Methods of fabricating the magnetic recording media are also provided.

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 zero in 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.aFe.sub.2-aO.sub.3  (1)

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 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)