Abstract: A magnetic recording medium comprising; a nonmagnetic support; a first under layer which is constituted by a nonmetal element, per se, a compound consisting of nonmetal elements, or a compound containing titanium and a nonmetal element; a second under layer containing at least one element selected from the group consisting of chromium, titanium, iridium, platinum, palladium, ruthenium, rhodium, rhenium and osmium; and a magnetic layer which contains a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic compound, in this order.

Abstract: A removable magnetic recording medium which is a removable disc medium for use in a magnetic recording system, wherein the removable disc medium is encased in a cartridge, a diameter of the disc medium is from 20 mm to 50 mm, and the disc medium comprises a flexible polymer support and at least one recording layer comprising a ferromagnetic metal alloy containing cobalt.

Abstract: A perpendicular magnetic recording medium comprising a substrate and a recording layer, the recording layer comprising a cobalt-containing ferromagnetic metal alloy and a non-magnetic oxide.

Abstract: A magnetic recording medium comprising a flexible support, a first recording layer, an intermediate layer and a second recording layer in this order, wherein the second recording layer comprises a ferromagnetic metal alloy comprising Co, Pt and Cr, and a nonmagnetic oxide.

Abstract: The present invention provides a magnetic recording medium, which comprises a chromium-containing primer layer and a magnetic layer at least on one surface of a nonmagnetic support member, said chromium-containing primer layer contains chromium and at least one type of element selected from a group of cobalt, beryllium, osmium, rhenium, titanium, zinc, tantalum, aluminum, molybdenum, tungsten, vanadium, iron, antimony, iridium, ruthenium, rhodium, platinum, palladium, silicon, and zirconium, and said magnetic layer comprises a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material.