Abstract: A magnetic recording medium that includes a substrate, an insulation layer applied onto a surface of the substrate, and a magnetic layer applied onto the insulation layer. The insulation layer is made from a redox-corrosion-inhibiting material. In one embodiment, the insulation layer inhibits redox corrosion by inhibiting electron transfer through the insulation layer (e.g., inhibits electron transfer between the substrate and the magnetic layer).

Abstract: A magnetic recording medium that includes a substrate, an insulation layer applied onto a surface of the substrate, and a magnetic layer applied onto the insulation layer. The insulation layer is made from a redox-corrosion-inhibiting material. In one embodiment, the insulation layer inhibits redox corrosion by inhibiting electron transfer through the insulation layer (e.g., inhibits electron transfer between the substrate and the magnetic layer).

Abstract: Techniques for writing data to a buffer region of a magnetic disk are described. In one example, a hard disk drive comprises a magnetic disk comprising a data buffer region including a first zone and a second zone. Data may be written to the magnetic disk using shingled magnetic recording (SMR) and the buffer region may be an exception region (E-region). A hard disk drive may be configured to calculate a position accuracy value associated with a data writing head. The hard disk drive may select one of the zones based on the position accuracy value. Further, a selected zone may have a determined zone format. The hard disk drive may be configured to write data to the selected zone using the determined zone format.

Abstract: A magnetic-recording-disk test-head. The magnetic-recording-disk test-head includes a slider, a test pad and a slider-surface-shape control mechanism. The slider includes a leading edge and a trailing edge. The test pad is disposed at a trailing-edge side of the slider and is configured to remove and to detect asperities on a magnetic-recording disk. The slider-surface-shape control mechanism is configured to change a shape of an air-bearing surface of the slider and is disposed at a leading-edge side of the slider.

Abstract: A magnetic-recording-disk test-head. The magnetic-recording-disk test-head includes a slider, a test pad and a slider-surface-shape control mechanism. The slider includes a leading edge and a trailing edge. The test pad is disposed at a trailing-edge side of the slider and is configured to remove and to detect asperities on a magnetic-recording disk. The slider-surface-shape control mechanism is configured to change a shape of an air-bearing surface of the slider and is disposed at a leading-edge side of the slider.

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 bit error rate is improved and, at the same time, an aging change due to thermal fluctuation is decreased. In one embodiment, a magnetic recording medium has first, second, third, and fourth magnetic layers stacked over the underlayer film on a substrate. The product (Brt2) of the residual magnetic flux density and film thickness of the second magnetic layer is smaller than the product (Brt3) of the residual magnetic flux density and film thickness of the third magnetic layer. The second magnetic layer has a thickness larger than that of the third magnetic layer and is anti-ferromagnetically coupled with the first magnetic layer by way of the first non-magnetic intermediate layer. The fourth magnetic layer is formed by way of a second non-magnetic intermediate layer above the third magnetic 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: 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: An inplane magnetic recording medium having high S/N and thermal stability and a reliable magnetic storage device having surface recording density of 50 megabit/mm2 or more is described. The magnetic recording medium includes magnetic layers formed on a nonmagnetic substrate with a plurality of ground layers therebetween, at least one of the ground layers formed from an alloy of a body-centered cubic structure containing Cr as a main component and B of from 2 atomic % to 12 atomic %. Main components of the magnetic layers include a lower magnetic layer containing Co and Cr of from 10 atomic % to 16 atomic %, with film thickness of from 1.5 nm to 4.5 nm, and an upper magnetic layer containing Co, coupling anti-ferromagnetically with the lower magnetic layer through nonmagnetic intermediate layers.

Abstract: A magnetic recording apparatus including a drive unit to drive the magnetic recording medium, a compound-type magnetic head, a means to move the magnetic head relative to the magnetic recording medium, and a means to process recording and retrieving signals generated by the magnetic head. The magnetic recording medium comprises a non-magnetic substrate and a magnetic layer formed thereon with three underlayers interposed inbetween. The magnetic layer is composed of a plurality of layers of Co-based alloy of hexagonal close-packed structure which are antiferromagnetically coupled to one another through a non-magnetic intermediate layer, said three underlayers including an amorphous alloy layer, a Ta layer, and a Cr-based alloy layer of body-centered cubic structure.

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 bit error rate is improved and, at the same time, an aging change due to thermal fluctuation is decreased. In one embodiment, a magnetic recording medium has first, second, third, and fourth magnetic layers stacked over the underlayer film on a substrate. The product (Brt2) of the residual magnetic flux density and film thickness of the second magnetic layer is smaller than the product (Brt3) of the residual magnetic flux density and film thickness of the third magnetic layer. The second magnetic layer has a thickness larger than that of the third magnetic layer and is anti-ferromagnetically coupled with the first magnetic layer by way of the first non-magnetic intermediate layer. The fourth magnetic layer is formed by way of a second non-magnetic intermediate layer above the third magnetic layer.

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: 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: An inplane magnetic recording medium having high S/N and thermal stability and a reliable magnetic storage device having surface recording density of 50 megabit/mm2 or more is described. The magnetic recording medium includes magnetic layers formed on a nonmagnetic substrate with a plurality of ground layers therebetween, at least one of the ground layers formed from an alloy of a body-centered cubic structure containing Cr as a main component and B of from 2 atomic % to 12 atomic %. Main components of the magnetic layers include a lower magnetic layer containing Co and Cr of from 10 atomic % to 16 atomic %, with film thickness of from 1.5 nm to 4.5 nm, and an upper magnetic layer containing Co, coupling anti-ferromagnetically with the lower magnetic layer through nonmagnetic intermediate layers.

Abstract: An inplane magnetic recording medium having high S/N and thermal stability and a reliable magnetic storage device having surface recording density of 50 megabit/mm2 or more is described. The magnetic recording medium includes magnetic layers formed on a nonmagnetic substrate with a plurality of ground layers therebetween, at least one of the ground layers formed from an alloy of a body-centered cubic structure containing Cr as a main component and B of from 2 atomic % to 12 atomic %. Main components of the magnetic layers include a lower magnetic layer containing Co and Cr of from 10 atomic % to 16 atomic %, with film thickness of from 1.5 nm to 4.5 nm, and an upper magnetic layer containing Co, coupling anti-ferromagnetically with the lower magnetic layer through nonmagnetic intermediate layers.

Abstract: It is an object of the present invention to provide a high reliability magnetic storage apparatus capable of performing writing and reading back of high density information. The magnetic storage apparatus is so configured as to have a longitudinal magnetic recording medium including: a magnetic layer formed on a non-magnetic substrate via a plurality of underlayers; the magnetic layer including a lower magnetic layer containing Ru in an amount of not less than 3 at % to not more than 30 at %, and Cr in an amount of not less than 0 at % to not more than 18 at %, and further containing at least one of B or C in an amount of not less than 0 at % to not more than 20 at %, and an upper magnetic layer containing Co as a main component disposed thereon via a non-magnetic intermediate layer.