A magnetic recording medium includes a substrate; a lower base layer formed on the substrate; and a (001) oriented L1.sub.0 magnetic layer formed on the lower base layer and including a first magnetic layer formed on the lower base layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing C, and a second magnetic layer formed on the first magnetic layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing oxide or nitride, the second magnetic layer further containing one or more elements selected from a group consisting of Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au and Pb as an additive.

The magnetic tape includes a magnetic layer having ferromagnetic powder and a binder on a non-magnetic support, in which the magnetic layer includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm.sup.3, and an edge shape of the timing-based servo pattern specified by a magnetic force microscope observation is a shape in which a difference (l.sub.99.9−l.sub.0.1) between a value l.sub.99.9 of a cumulative frequency function of 99.9% of a position deviation width from an ideal shape in a longitudinal direction of the magnetic tape and a value l.sub.0.1 of the cumulative frequency function of 0.1% thereof is equal to or smaller than 180 nm.

Hexagonal ferrite powder has an average particle size falling within a range of 10 nm to 50 nm, a switching field distribution SFD.sub.23° C. measured at a temperature of 23° C. that is less than or equal to 0.80, and a ratio of a switching field distribution SFD.sub.−190° C. that is measured at a temperature of −190° C. to the SFD.sub.23° C. (SFD.sub.−190° C./SFD.sub.23° C.) that is greater than 0.80.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.

A base for a magnetic recording medium, includes an aluminum alloy substrate, and a nickel alloy film provided on at least one principal surface of the aluminum alloy substrate. The nickel alloy film includes Mo in a range of 0.5 wt % to 3 wt %, P in a range of 11 wt % to 15 wt %, and Fe in a range of 0.0001 wt % to 0.001 wt %.

According to one embodiment, a magnetic recording medium includes a substrate, a magnetic recording layer on the substrate, and a first protective layer of carbon formed on the magnetic recording layer by thermal CVD.

Hexagonal ferrite magnetic particles have an activation volume ranging from 1,000 nm.sup.3 to 1,500 nm.sup.3, and ΔE.sub.10%/kT, thermal stability at 10% magnetization reversal, is equal to or greater than 40.

A magnetic recording medium of the present invention is a magnetic recording medium including a non-magnetic substrate; a non-magnetic layer that is formed on one of principal surfaces of the non-magnetic substrate and contains a non-magnetic powder, a binder, and a lubricant; and a magnetic layer that is formed on a principal surface of the non-magnetic layer opposite to the non-magnetic substrate and contains a magnetic powder and a binder. The magnetic powder has an average particle size between 10 nm and 35 nm inclusive. The lubricant is migratable to the magnetic layer and forms a lubricant layer on a surface of the magnetic layer when a pressure is applied to the magnetic layer. When spacing of the surface of the magnetic layer before and after washing the lubricant with n-hexane is measured with a TSA (Tape Spacing Analyzer), the value of the spacing after washing is 3 to 10 nm, and the value of the spacing before washing is 1 to 5 nm smaller than the value of the spacing after washing.

Magnetic recording media including a soft magnetic underlayer (SUL) formed over an oxidized pre-seed layer. In some examples, the pre-seed layer is oxidized to reduce an amount of intermixing between the pre-seed layer and the SUL. The reduction in intermixing via oxidation can lead to improved recording performance of the recording media that are deposited on the SUL. In particular, media overwrite, signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a deposition apparatus may be modified to inject oxygen during pre-seed layer deposition to oxidize the pre-seed layer.

The magnetic tape cartridge includes a magnetic tape, and a cartridge reel, in which, in the magnetic tape, a minimum winding deviation occurrence load measured after the magnetic tape is rewound around the cartridge reel by applying a tension of 0.20 N in a longitudinal direction of the magnetic tape is 200 N or less.