1060results about How to "Improve recording density" patented technology

The magnetic signal reproduction system comprises a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support and a reproduction head, wherein a number of protrusions equal to or greater than 10 nm in height on the magnetic layer surface, as measured by an atomic force microscope, ranges from 50 to 2500/10,000 μm², a quantity of lubricant on the magnetic layer surface, denoted as a surface lubricant index, ranges from 0.5 to 5.0, a surface abrasive occupancy of the magnetic layer ranges from 2 to 20 percent, the reproduction head is a magnetoresistive magnetic head comprising a spin-valve layer, the spin-valve layer comprises a magnetization free layer, a magnetization pinned layer and an antiferromagnetic layer, and the antiferromagnetic layer is comprised of alloy comprising iridium and manganese, and the reproduction head comes in sliding contact with the magnetic recording medium during signal reproduction.

The present invention relates to a magnetic ring unit and a magnetic memory device; an object of the invention is to control the direction of rotation of the magnetic flux freely and with high reproducibility in a simple structure without using a thermal process such as pinning; and a magnetic ring unit is formed of a magnetic ring in eccentric ring form where the center of the inner diameter is located at a decentered position relative to the center of the outer diameter.

A magnetic tape comprising a non-magnetic substrate and at least one magnetic layer formed on one surface of the non-magnetic substrate, characterized in that magnetic particles contained in an uppermost magnetic layer of the magnetic layer are substantially granular particles with a particle size of 30 nm or less, and that the ratio of a coercive force Hc_M in the machine direction to a coercive force Hc_T in the transverse direction, i.e., [Hc_M/Hc_T], is at least 2.2. This magnetic tape has a capacity capable of corresponding to mass storage of 1 TB or more, and achieves a high ratio of reproducing output to noises (C/N), particularly for signals within a short wavelength range, thus showing excellent high-density recording performance.

The magnetic tape device includes a magnetic tape and a TMR head, in which the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

A magnetic device includes a first magnetic layer having at least one magnetic material layer, a second magnetic layer having at least one magnetic material layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, a third magnetic layer including a ferromagnetic material with a fixed magnetization direction, and a pair of electrodes. The pair of electrodes are operable to pass a current through a laminated body including the first and second magnetic layers, the nonmagnetic layer, and the third magnetic layer.

An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system.

In a magnetic disk apparatus including a magnetic disk, a recording head that writes information on the magnetic disk, and a controller that controls a writing operation of the recording head to the magnetic disk, the controller controls the writing operation such that the recording head writes information on a region including a target track and a portion of track adjacent thereto in an overlapping manner while position-shifting in a radial direction of the magnetic disk and a first writing frequency to a track on which information is last written is higher than a second writing frequency to another track.

It is aimed to provide a perpendicular magnetic recording medium capable of dealing with an ultra-higher recording density than before and its manufacturing method.

The present invention concerns a perpendicular magnetic recording medium including at least a seed layer made of noncrystalline ceramic, a crystalline orientation control layer and a magnetic layer made of a material mainly containing a FePt alloy in this order on a substrate. This perpendicular magnetic recording medium is suitably manufactured by forming at least the seed layer, the orientation control layer and the magnetic layer made of the material mainly containing the FePt alloy in this order on the substrate by sputtering, wherein the magnetic layer is formed at a predetermined temperature of 500° C. or less.

A thin-film magnetic head that has a configuration in which the element-formed surface and the opposed-to-medium surface are perpendicular to each other, and a light source is sufficiently distanced from the medium surface is provided. The head comprises at least one near-field-light-generating layer for heating a part of a magnetic medium during write operation by generating a near-field light, having a shape tapered toward a head end surface on the opposed-to-medium surface side, and comprising a near-field-light-generating portion having a light-received surface and a tip reaching the head end surface on the opposed-to-medium surface side, and the light-received surface being sloped in respect to the element-formed surface and being provided in a position where an incident light propagating from a head end surface opposite to the opposed-to-medium surface can reach at least a part of the light-received surface.

A perpendicular magnetic recording medium is disclosed that achieves improved recordability without deteriorating thermal stability by reducing the switching field. A perpendicular magnetic recording medium of the invention has a first magnetic recording layer and a second magnetic recording layer between with is interposed a coupling layer that ferromagnetically couples the two layers. The first and second magnetic recording layers satisfy an inequality Ku₁T₁>Ku₂T₂ in the case where Hk₁ >Hk₂ and an inequality Ku₁T₁<Ku₂T₂ in the case where Hk₁<Hk₂, where Hk₁ and Hk₂ are anisotropy magnetic fields, Ku₁ and Ku₂ are uniaxial anisotropy constants, and T₁ and T₂ are thicknesses of the first magnetic recording layer and the second recording layer, respectively. An exchange coupling energy between the magnetic recording layers is preferably at least 5×10⁻³ erg/cm². Advantageously, the coupling layer is mainly composed of a material selected from V, Cr, Fe, Co, Ni, Cu, Nb, Mo, Ru, Rh, Ta, W, Re, and Ir, and has a thickness of at most 2 nm. At least one of the magnetic recording layers preferably has a granular structure.

A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.

To provide a method for manufacturing a perpendicular magnetic recording medium, which is capable of coping with the much higher recording density.

Disclosed is a method for manufacturing a perpendicular magnetic recording medium to be used for recording information by a perpendicular magnetic recording system, including at least a soft magnetic layer, an intermediate layer, and a magnetic recording layer on a substrate, characterized in that the method includes the step of:

• composing the intermediate layer of consecutive N layers (provided that N is an integer of at least 3 or more), depositing a first layer containing ruthenium (Ru) as a main component, first; setting a gas pressure during the deposition to the pressure which is higher than or the same as that in the first layer; depositing a second layer containing ruthenium (Ru), or ruthenium (Ru) containing oxygen or an oxide as a main component; and adjusting so that the oxygen content remains constant, or increases toward the uppermost layer in the second layer and succeeding layers.

In a method of manufacturing a magnetic disk including at least a magnetic recording layer on a substrate 1 and used for vertical magnetic recording, in a step of forming, on the substrate 1, the magnetic recording layer composed of a ferromagnetic layer 5 having a granular structure and an exchange energy control layer 7 constituted by a laminated layer formed on the ferromagnetic layer 5, at least the exchange energy control layer 7 is formed through sputtering in an atmosphere of a rare gas having a greater mass than an argon gas. The rare gas having a greater mass than the argon gas is a krypton (Kr) gas, for example. The exchange energy control layer 7 is a laminated layer composed of a first layer containing Co or a Co-alloy and a second layer containing palladium (Pd) or platinum (Pt), for example.

To provide a method for manufacturing a perpendicular magnetic recording medium which has improved electromagnetic conversion characteristics, and thus making it possible to achieve the much higher recording density.

Disclosed is a method for manufacturing a perpendicular magnetic recording medium to be used for recording information by a perpendicular magnetic recording system, the perpendicular magnetic recording medium including at least a soft magnetic layer, an underlayer, and a magnetic recording layer on a substrate. In the method, the underlayer is formed by sputtering deposition, including a low-gas-pressure deposited layer deposited at a low gas pressure during the deposition, and a high-gas-pressure deposited layer deposited at a high gas pressure during the deposition. The high-gas-pressure deposited layer is formed of a multilayer deposited by decreasing a deposition rate in a stepwise manner.