Abstract: An object is to automatically detect the positions of spike noise, create a distribution diagram, and perform pass/fail decisions. The cross-correlation function of the signal waveform from a magnetic head 1 and a reference waveform simulating spike noise is used in extraction of spike noise. The number of peaks in the cross-correlation function exceeding a threshold value is counted, and quantitative evaluation of spike noise is performed.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nomnagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

Abstract: An object is to automatically detect the positions of spike noise, create a distribution diagram, and perform pass/fail decisions. The cross-correlation function of the signal waveform from a magnetic head 1 and a reference waveform simulating spike noise is used in extraction of spike noise. The number of peaks in the cross-correlation function exceeding a threshold value is counted, and quantitative evaluation of spike noise is performed.

Abstract: A magnetic storage device has a magnetic layer, the magnetic crystal grains of which are separated by a nonmagnetic phase. The typical crystal grain is in the approximate shape of a sphere or an ellipsoid. The thickness of the magnetic crystal grains, which is in the direction perpendicular to the surface or the film, is smaller than that of the thickness of the magnetic film. The ratio of the coercive force, which is measured in the circumferential direction, to the coercive force, which is measured in the radial direction, (the orientation ratio of the coercive force), is larger than 1.0, but preferably nor greater than 3.0. Further, the area fraction of the magnetic grains having an extended axis within 30° from the circumferential direction is equal to or more than 45%.

Abstract: A magnetic recording apparatus provides improved resolution and S/N without adversely affecting thermal stability. An angle formed by the direction of easy magnetization of a recording layer and the direction normal to a magnetic recording medium is in the range between 5° and 55°, the easy magnetization direction is from a back surface of the recording layer toward a front surface thereof, and when a recording track direction is from the upstream of the direction of transportation of the medium toward the downstream thereof, an angle formed by the direction of a projection of the easy magnetization direction on the medium plane and the recording track direction is in the range between 0° and 70°.

Abstract: A magnetic recording apparatus provides improved resolution and S/N without adversely affecting thermal stability. An angle formed by the direction of easy magnetization of a recording layer and the direction normal to a magnetic recording medium is in the range between 5° and 55°, the easy magnetization direction is from a back surface of the recording layer toward a front surface thereof, and when a recording track direction is from the upstream of the direction of transportation of the medium toward the downstream thereof, an angle formed by the direction of a projection of the easy magnetization direction on the medium plane and the recording track direction is in the range between 0° and 70°.

Abstract: An object is to automatically detect the positions of spike noise, create a distribution diagram, and perform pass/fail decisions. The cross-correlation function of the signal waveform from a magnetic head 1 and a reference waveform simulating spike noise is used in extraction of spike noise. The number of peaks in the cross-correlation function exceeding a threshold value is counted, and quantitative evaluation of spike noise is performed.

Abstract: There is provided a perpendicular magnetic recording medium comprising a non-magnetic layer having a face-centered cubic structure, an antiferromagnetic layer provided on the non-magnetic layer, a soft magnetic underlayer provided on the antiferromagnetic layer, and a perpendicular recording layer provided on the soft magnetic underlayer, which magnetic recording medium makes it possible to realize a recording density not less than 50 Gb/in2 and makes the error rate thereof low while suppressing the spike noise.

Abstract: Disclosed are a double-layer perpendicular magnetic recording medium having a high medium S/N at a recording density of 50 Gbit or more per square inch and a magnetic storage apparatus with high reliability, which shows a low error rate. In the perpendicular magnetic recording medium in which a pre-coating layer, a soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer are sequentially formed on a substrate, the soft magnetic underlayer contains Fe, Ta and C as main components, a Ta concentration is set to a range from 8 at % to 15 at % , and a ratio of a C concentration to the Ta concentration (C concentration/Ta concentration) is set to a range from 0.5 to 0.9.

Abstract: This invention provides a magnetic recording/reproducing apparatus with high storage capability and an areal recording density over 7.75 Gbits/cm2, in which fluctuation of readback output and decay of magnetization or erasure of recorded magnetization in the recording layer are prevented. On the substrate of a magnetic disk, a soft magnetic underlayer and a perpendicular recording layer are formed in order, where the soft magnetic underlayer has a triple-layered structure in which a domain control layer including an anti-ferromagnetic layer is sandwiched between two first and second soft magnetic layers. Given that thickness of the first soft magnetic layer is d1 and thickness of the second soft magnetic layer is d2, d1 and d2 should be between 25 nm and 150 nm and a ratio of d1/d2 should fall within a range of 0.3 to 1.5. Thereby, magnetic domains in the soft magnetic underlayer of a perpendicular magnetic recording medium are controlled and magnetic domain wall motion can be inhibited.

Abstract: A soft magnetic underlayer includes a first amorphous soft magnetic layer to which an exchange bias magnetic field is applied directly from an antiferromagnetic layer or via a ferromagnetic layer, and a second amorphous soft magnetic layer which is formed on the first amorphous soft magnetic layer via a non-magnetic layer. The first amorphous soft magnetic layer and the second amorphous soft magnetic layer are antiferromagnetically coupled.

Abstract: There is provided a perpendicular magnetic recording medium comprising a non-magnetic layer having a face-centered cubic structure, an antiferromagnetic layer provided on the non-magnetic layer, a soft magnetic underlayer provided on the antiferromagnetic layer, and a perpendicular recording layer provided on the soft magnetic underlayer, which magnetic recording medium makes it possible to realize a recording density not less than 50 Gb/in2 and makes the error rate thereof low while suppressing the spike noise.

Abstract: A double layer perpendicular magnetic recording medium having a high medium S/N ratio at a recording density of 50 Gb/in2 or higher and a magnetic storage apparatus with a lower error rate and excellent reliability are provided. In a perpendicular magnetic recording medium in which a soft magnetic underlayer 12, an intermediate layer 13, and a perpendicular magnetic recording layer 14 are sequentially formed on a substrate 11, the intermediate layer 13 is made to be a non-magnetic amorphous alloy, in which Ni is a main component and Zr is contained, and the soft magnetic underlayer 12 is constituted of ferromagnetic nan-crystals precipitated by annealing.

Abstract: Provided are a double-layer perpendicular magnetic recording medium having a high medium S/N at an areal recording density of 50 Gbits or more per square inch, and a magnetic storage apparatus having excellent reliability with a low error rate. The perpendicular magnetic recording medium is formed by sequentially laminating a domain control layer, an amorphous soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer on a substrate. The domain control layer is a triple-layer film formed by laminating a first polycrystalline soft magnetic layer, a disordered antiferromagnetic layer, and a second polycrystalline soft magnetic layer from a substrate side.

Abstract: Disclosed herein are a magnetic recording medium having a high coercive force and being capable of high-density writing/reading, a magnetic recording apparatus equipped with said magnetic recording medium, and a process for producing said magnetic recording medium.

Abstract: A double layer perpendicular magnetic recording medium having a high medium S/N ratio at a recording density of 50 Gb/in2 or higher and a magnetic storage apparatus with a lower error rate and excellent reliability are obtained with a structure having soft magnetic underlayer 12, an intermediate layer 13 and a perpendicular magnetic recording layer 14 are sequentially formed on a substrate 11. The, intermediate layer 13 is made to be a non-magnetic amorphous alloy, in which Ni is a main component and Zr is contained, and the soft magnetic underlayer 12 is constituted of ferromagnetic nano-crystals precipitated by annealing.

Abstract: A magnetic recording apparatus provides improved resolution and S/N without adversely affecting thermal stability. An angle formed by the direction of easy magnetization of a recording layer and the direction normal to a magnetic recording medium is in the range between 5° and 55°, the easy magnetization direction is from a back surface of the recording layer toward a front surface thereof, and when a recording track direction is from the upstream of the direction of transportation of the medium toward the downstream thereof, an angle formed by the direction of a projection of the easy magnetization direction on the medium plane and the recording track direction is in the range between 0° and 70°.

Abstract: Provided are a double-layer perpendicular magnetic recording medium having a high medium S/N at an areal recording density of 50 Gbits or more per square inch, and a magnetic storage apparatus having excellent reliability with a low error rate. The perpendicular magnetic recording medium is formed by sequentially laminating a domain control layer, an amorphous soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer on a substrate. The domain control layer is a triple-layer film formed by laminating a first polycrystalline soft magnetic layer, a disordered antiferromagnetic layer, and a second polycrystalline soft magnetic layer from a substrate side.

Abstract: A magnetic recording medium having a high coercive force and being capable of high-density writing/reading has a substrate, a soft magnetic layer, a non-magnetic intermediate layer, a magnetic layer, a protective layer, and a lubricating layer. The magnetic layer is characterized by stacking fault density and dispersion of particle diameters. The stacking fault density should preferably be no larger than 0.05, and the dispersion of particle diameters should preferably be no larger than 0.4. The magnetic recording medium has a coercive force larger than 4000 Oe, is highly stable to thermal decay, and has a recording density in excess of 50 Gbit/in2.

Abstract: A perpendicular recording medium includes a perpendicular recording layer formed over a substrate through a soft magnetic underlayer, the soft magnetic underlayer then being arranged to include a plurality of soft magnetic layers physically separated by a non-magnetic layer, and further, the soft magnetic layers being formed of nanocrystals, with these arrangements, local magnetic loops are formed between the soft magnetic layers that are adjacent to each other through the non-magnetic layer, thereby suppressing spike noise and modulation that arises from the soft magnetic underlayer.