Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium with less medium noise, excellent overwrite characteristics, and scratch resistance. According to one embodiment, when an Ar gas with addition of a micro-amount of oxygen is used upon forming an upper Ru intermediate layer, a micro-structure of a magnetic layer formed thereon can be formed in a state where no magnetic oxide region is segregated and the magnetic crystal grains are isolated. In this case, a gas pressure for forming the upper intermediate layer is set to 5 Pa or more and 12 Pa or less which is a region much higher compared with 0.5 Pa or more and 1 Pa for the lower Ru intermediate layer.

Abstract: In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron.

Abstract: An AFC magnetic recording medium having a three-layered ferromagnetic structure capable of reducing noises without deteriorating thermal stability is provided in order to achieve ultra-high recording density.

Abstract: In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron.

Abstract: In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron.

Abstract: A longitudinal magnetic recording medium having a high medium S/N, with no problems in view of the overwrite characteristic, excellent in the bit error rate and sufficiently stable also to thermal fluctuations is provided. In one embodiment, a first underlayer, second underlayer, and a third underlayer are formed on a substrate and, further, a first magnetic layer, a spacer layer including Ru as a main ingredient, a second magnetic layer, and a third magnetic layer are formed in adjacent with each other in this order. The thickness of the second magnetic layer is made larger than the thickness of the third magnetic layer and the total for the concentrations of cobalt and platinum obtained in the second magnetic layer is not more than the total for the concentrations of cobalt and platinum contained in the third magnetic layer.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium with less medium noise, excellent overwrite characteristics, and scratch resistance. According to one embodiment, when an Ar gas with addition of a micro-amount of oxygen is used upon forming an upper Ru intermediate layer, a micro-structure of a magnetic layer formed thereon can be formed in a state where no magnetic oxide region is segregated and the magnetic crystal grains are isolated. In this case, a gas pressure for forming the upper intermediate layer is set to 5 Pa or more and 12 Pa or less which is a region much higher compared with 0.5 Pa or more and 1 Pa for the lower Ru intermediate layer.

Abstract: Fluctuation of read/write characteristics during mass production is suppressed for a perpendicular magnetic recording medium having a perpendicular recording layer of a bi-layered structure, in which a first Co—Cr—Pt alloy magnetic layer containing an oxide and a second Co—Cr—Pt magnetic layer are formed successively. According to one embodiment, in a perpendicular magnetic recording medium, an adhesion layer, a soft magnetic underlayer, a seed layer, an intermediate layer, a perpendicular recording layer, a protective layer, and a lubricating layer are successively formed on a substrate. The perpendicular recording layer has a bi-layered structure in which a first Co—Cr—Pt alloy magnetic layer containing an oxide and a second Co—Cr—Pt alloy magnetic layer containing a marker element for measurement of a thickness selected from Mo, Mn, and V are successively formed, and the content of the marker element for measurement of thickness is about 1.5 at % or more and about 5 at % or less.

Abstract: A magnetic recording medium capable of attaining high in-plane recording density of 100 Mbits or more per 1 mm2 is provided. Magnetic recording medium is provided in which underlayers, a first magnetic layer, a first intermediate layer, a second magnetic layer, a second intermediate layer, a third magnetic layer, a protection layer and lubrication layer are formed in this order above a substrate. Each of the third magnetic layer and the second magnetic layer comprises a Co-based alloy containing at least Pt, Cr and B. The concentration of Pt contained in the second magnetic layer is not more than that in the third magnetic layer.

Abstract: A large-capacity, low-cost, longitudinal magnetic recording medium capable of ultra-high-density recording of 70 Gigabits or more per square inch is disclosed. The longitudinal magnetic recording medium of the present invention comprises a first seed layer, a second seed layer, a first underlayer, a second underlayer, and a magnetic layer, which are formed on a nonmagnetic substrate in this order. A material containing at least Al and any one of Ru and Re is used to form the second seed layer, and a material containing at least any one of Co and Ni and one or both of Al and Ti is used to form the first underlayer. It is also possible to use Cr or a Cr alloy containing Cr and at least one element selected from the constituent element group A consisting of Ti, Mo, and W for forming the second seed layer.

Abstract: A magnetic recording medium having a substrate, an under-layer formed on the substrate, a magnetic layer formed on the substrate and a protective layer formed on the magnetic layer. The magnetic layer comprises Co, Cr and Pt with a thickness being from 10 nm to 22 nm. Further, a coercivity of the magnetic layer is not less than 2000 Oe, and a fluctuation field of magnetic viscosity at a field strength equal to remanence coercivity or coercivity is not less than 30 Oe.

Abstract: A magnetic recording material is provided which has high medium S/N, and provides excellent overwriting characteristic, excellent thermal fluctuation and sufficient stability against thermal fluctuation. In one embodiment, a first underlayer comprising one of alloys of a Ti—Co alloy, a Ti—Co—Ni alloy, and an Ni—Ta alloy, a second underlayer comprising a W—Co alloy or Ta, and a third underlayer of a body-centered cubic structure comprising a Cr—Ti—B alloy or a Cr—Ti alloy are disposed over a substrate. A first magnetic layer comprising a Co—Cr—B alloy or a Co—Cr—Ta alloy, a second magnetic layer comprising a Co—Cr—Pt—B—Ta alloy, a third magnetic layer comprising a Co—Cr—Pt—B alloy, and a protective film are disposed further thereover. An intermediate region (Th) is disposed between the second magnetic layer and the third magnetic layer, the intermediate region having a higher oxygen concentration than those of the magnetic layers.

Abstract: A magnetic recording medium which comprises a substrate, an orientation control layer formed directly thereon, and a Co alloy magnetic layer formed thereon directly or indirectly with a Cr underlayer or Cr alloy underlayer interposed between them, the orientation control layer having an L10 crystal structure, L21 crystal structure, fcc crystal structure, or B2 (CsCl) crystal structure containing B, owing to this construction, has a high coercive force and a low noise level and is only slightly vulnerable to thermal fluctuation.

Abstract: In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron.

Abstract: A magnetic recording system includes an in-plane magnetic recording medium having a magnetic layer fabricated on a single underlayer or on a plurality of underlayers respectively fabricated on a substrate; a driver unit for driving the in-plane magnetic recording medium in a write direction; a magnetic head having a read unit and a write unit; a unit for moving the magnetic head relative to the in-plane magnetic recording medium; and a read/write signal processing unit for reading an output signal from the magnetic head and writing an input signal to the magnetic recording media, wherein the read unit of the magnetic head is a magnetoresistive head and the single underlayer or at least one of the plurality of underlayers is made of Co-containing amorphous material or fine crystal material, or is made of alloy material, the alloy material having as the main components at least one element selected from a group consisting of Cr, Mo, V and Ta and containing at least one element selected from a group consisting o

Abstract: An AFC magnetic recording medium having a three-layered ferromagnetic structure capable of reducing noises without deteriorating thermal stability is provided in order to achieve ultra-high recording density.

Abstract: A longitudinal magnetic recording medium having a high medium S/N, with no problems in view of the overwrite characteristic, excellent in the bit error rate and sufficiently stable also to thermal fluctuations is provided. In one embodiment, a first underlayer, second underlayer, and a third underlayer are formed on a substrate and, further, a first magnetic layer, a spacer layer including Ru as a main ingredient, a second magnetic layer, and a third magnetic layer are formed in adjacent with each other in this order. The thickness of the second magnetic layer is made larger than the thickness of the third magnetic layer and the total for the concentrations of cobalt and platinum obtained in the second magnetic layer is not more than the total for the concentrations of cobalt and platinum contained in the third magnetic layer.

Abstract: A magnetic recording medium having a substrate, an under-layer formed on the substrate, a magnetic layer formed on the substrate and a protective layer formed on the magnetic layer. The magnetic layer comprises Co, Cr and Pt with a thickness being from 10 nm to 22 nm. Further, a coercivity of the magnetic layer is not less than 2000 Oe, and a fluctuation field of magnetic viscosity at a field strength equal to remanence coercivity or coercivity is not less than 30 Oe.

Abstract: A large-capacity magnetic storage apparatus is disclosed, capable of performing ultra-high density magnetic recording of 50 gigabits or more per 1 square inch. In a perpendicular magnetic recording medium having a non-magnetic intermediate layer and a magnetic recording layer sequentially formed, the non-magnetic intermediate layer is composed of a layer having a face-centered cubic structure and containing a non-magnetic elements excluding Pt. Specifically, the intermediate layer mainly contains at least one selected from the group of elements constituted of Al, Cu, Rh, Pd, Ag, Ir and Au, and is composed of a film having a face-centered cubic (f. c. c.) structure. The magnetic recording layer contains at least Co, Cr and Pt, and is composed of a film having a hexagonal close-packed (h. c. p.) structure. More preferably, a non-magnetic h. c. p. intermediate layer is provided between the non-magnetic intermediate layer and the magnetic recording layer.

Abstract: A magnetic recording medium capable of attaining high in-plane recording density of 100 Mbits or more per 1 mm2 is provided. Magnetic recording medium is provided in which underlayers, a first magnetic layer, a first intermediate layer, a second magnetic layer, a second intermediate layer, a third magnetic layer, a protection layer and lubrication layer are formed in this order above a substrate. Each of the third magnetic layer and the second magnetic layer comprises a Co-based alloy containing at least Pt, Cr and B. The concentration of Pt contained in the second magnetic layer is not more than that in the third magnetic layer.