Abstract: According to one embodiment, a magnetic recording device includes a magnetic recording head and a magnetic recording medium. The magnetic recording head includes a main magnetic pole, a shield and a stacked structure. The main magnetic pole has a medium facing surface and a main magnetic pole side surface. The shield has a shield side surface. The stacked structure is provided between the main magnetic pole and shield, and includes first and second magnetic layers, and an intermediate layer. The magnetic recording medium includes a backing layer and a magnetic recording layer. A distance between an end portion of the medium facing surface on a side of the stacked structure and the backing layer is twice or more of a distance between the main magnetic pole side surface and the shield side surface.

Abstract: An example magnetic writing head includes a main magnetic pole, a coil to generate an ampere magnetic field to magnetize the main magnetic pole to cause the magnetized main magnetic pole to generate a magnetic field, and a laminated body. The laminated body includes a first magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole and a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole.

Abstract: An example magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes is operable to pass a current through the laminated body.

Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field perpendicular to a recording medium, a trailing-shield pole opposed to the main pole with a recording gap therebetween, a high-frequency oscillator between the main pole and the trailing-shield pole in the recording gap, configured to produce a high-frequency magnetic field, a magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the main pole, and a highly oriented magnetic layer of a soft magnetic material superposed on the magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the high-frequency oscillator.

Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a return pole opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between respective facing surfaces of the main pole and the return pole and configured to produce a high-frequency magnetic field. At least one of the main and return poles faces the high-frequency oscillator and includes a laminated structure portion includes a magnetic layer and a nonmagnetic layer laminated to one another.

Abstract: According to one embodiment, a magnetic head includes a reproducing section. The reproducing section detects a medium magnetic field recorded in a magnetic recording medium. The reproducing section includes a stacked film and a magnetic field application unit. The stacked film includes a first magnetization layer and a second magnetization layer. The first magnetization layer has a perpendicular magnetic anisotropy. A magnetization of the first magnetization layer being is fixed. The second magnetization layer is stacked with the first magnetization layer and oscillates. The magnetic field application unit is stacked with the stacked film and applies a bias magnetic field having a component along the first axis to the stacked film. A resistance of the stacked film changes in accordance with the medium magnetic field when a current not less than a value at which the second magnetization layer oscillates is passed.

Abstract: It is made possible to provide a magnetic head that generates a sufficient high-frequency magnetic field for assisting recording operations, and a magnetic recording device that includes the magnetic head. A magnetic head includes: a recording magnetic pole; a return yoke magnetically coupled to the recording magnetic pole; and at least two spin torque oscillators provided near the recording magnetic pole.

Abstract: 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.

Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole, a shield, and a stacked structure body. The shield is provided to oppose the main magnetic pole. The stacked structure body is provided between the main magnetic pole and the shield. The stacked structure body includes a first magnetic layer, a second magnetic layer, and an intermediate layer. The first magnetic layer has coercivity lower than a magnetic field applied from the main magnetic pole. A size of a film surface of the second magnetic layer is larger than a size of a film surface of the first magnetic layer. The intermediate layer is provided between the first magnetic layer and the second magnetic layer and is made of a nonmagnetic material. A current is configured to pass between the first magnetic layer and the second magnetic layer.

Abstract: A magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes are operable to pass a current through the laminated body.

Abstract: According to one embodiment, a disk drive has a magnetic disk and a magnetic head having a spin-torque oscillator. The disk drive further has a head amplifier IC configured to supply a write signal and a drive signal to the magnetic head. The write signal corresponds to write data. The drive signal is supplied to generate a high-frequency magnetic field. The head amplifier IC continuously supplies a drive signal of normal level to the spin-torque oscillator, and supplies a drive signal of high level higher than the normal level, only for a prescribed time after the polarity inversion of the write signal.

Abstract: A recording head including a first electrode, a first magnetic layer, a second magnetic layer, a first intermediate layer, a third magnetic layer, a second electrode, and a magnetic pole.

Abstract: According to one embodiment, a recording track has a surface modification layer in the surface region. This surface modification layer has an anisotropic magnetic field Hk reduced from that of a region between adjacent recording tracks.

Abstract: A magnetic recorder includes: a magnetic recording medium; a reproducing head; a magnetic recording head including: a main magnetic pole; a first magnetic layer containing a TM alloy; a second magnetic layer containing a TM alloy or an RE-TM alloy; a third magnetic layer containing an RE-TM alloy; a first intermediate layer provided between the first magnetic layer and the second magnetic layer; and a second intermediate layer provided between the second magnetic layer and the third magnetic layer; and a signal processing portion which performs signal writing into the magnetic recording medium by using the magnetic recording head and reading from the magnetic recording medium by using the reproducing head.

Abstract: According to one embodiment, there is provided a spin torque oscillator including an oscillation layer formed of a magnetic material, a spin injection layer formed of a magnetic material and configured to inject a spin into the oscillation layer, and a current confinement layer including an insulating portion formed of an oxide or a nitride and a conductive portion formed of a nonmagnetic metal and penetrating the insulating portion in a direction of stacking. The conductive portion of the current confinement layer is positioned near a central portion of a plane of a device region including the oscillation layer and the spin injection layer.

Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole generating a recording magnetic field in a magnetic recording medium, a return yoke paired with the main magnetic pole and a spin torque oscillator interposed between the main magnetic pole and the return yoke and including a first magnetic layer, a second magnetic layer and a third magnetic layer of Fe4N, the second magnetic layer being interposed between the first magnetic layer and the third magnetic layer, wherein the magnetic recording head is configured to allow a current for oscillation to flow in a direction from the first magnetic layer to the third magnetic layer.

Abstract: An optical disc apparatus including means for calculating a spherical aberration correction quantity of an object lens, reproduced information signal generation means and spherical aberration correction means conducts spherical aberration correction, finds a spherical aberration correction quantity suitable for another layer by calculation on the basis of the obtained spherical aberration correction quantity, and sets the correction quantity as an initial correction quantity of spherical aberration correction. An optical disc apparatus including tilt correction quantity calculation means, reproduced information signal generation means and tilt adjustment means conducts tilt adjustment, finds a tilt correction quantity suitable for another layer by calculation on the basis of the obtained tilt correction quantity, and sets the correction quantity as an initial correction quantity of tilt adjustment.

Abstract: A magnetic recording head includes a recording magnetic pole, and a spin oscillation device including a first magnetic layer having at least one magnetic material layer, a second magnetic layer having at least one magnetic material layer, and a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. The first magnetic layer and the second magnetic layer are antiferromagnetically coupled and/or magnetostatically coupled to each other. The first magnetic layer and the second magnetic layer are laminated in a direction generally parallel to a medium facing surface and generally parallel to a side surface of the recording magnetic pole intersecting with the medium facing surface.

Abstract: It is made possible to provide a magnetic head that can stabilize the high-frequency magnetic field generated from the spin torque oscillator. A magnetic head includes: first and second main magnetic poles; and a spin torque oscillator provided between the first and second main magnetic poles.

Abstract: A magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes operable to pass a current through the laminated body. The laminated body includes a first magnetic layer, a second magnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. A lamination direction of the laminated body is substantially parallel to a medium moving direction. In a first direction parallel to an air bearing surface and perpendicular to the lamination direction, the laminated body has a protruding portion that protrudes beyond an end of a surface of the main magnetic pole facing the laminated body.