Abstract: According to one embodiment, there is provided a magnetic recording head which records information on a magnetic recording medium, including an ABS surface, a near-field light generating unit, a heat conducting unit, and a heat absorbing unit. The ABS surface is opposed to the magnetic recording medium. The near-field light generating unit is disposed on the ABS surface. The heat conducting unit is formed by a heat conductor disposed in contact with the near-field light generating unit. The heat absorbing unit is disposed in contact with the heat conducting unit adjacently to the near-field light generating unit in a direction along the ABS surface.

Abstract: A magnetic disk device of an embodiment includes a magnetic disk, a magnetic head, a laser-beam-intensity control unit, a reproduced-signal detecting unit, and a magnetic-disk evaluating unit. The magnetic head reads a signal recorded in the magnetic disk, or performs magnetic recording while irradiating a laser beam onto the magnetic disk. The laser-beam-intensity control unit controls the intensity of the laser beam. The reproduced-signal detecting unit detects the signal read by the magnetic head. The magnetic-disk evaluating unit evaluates the signal read from the magnetic head, on the basis of a relation between a noise level detected from the signal read by the magnetic head, and the intensity of the laser beam.

Abstract: A magnetic recording head includes a main magnetic pole generating a recording magnetic field, a trailing shield, a recording coil generating a magnetic field and a high frequency oscillator. The trailing shield includes a magnetic region including a gap side end surface facing a write gap and a nonmagnetic film arranged in the vicinity of the write gap in the trailing shield, and within a plane including track width direction centers of the main magnetic pole and the high frequency oscillator and being perpendicular to a recording layer of a recording medium, a film thickness of the nonmagnetic film along a track moving direction is substantially equivalent to or more than a half of a distance from the gap side end surface to the nonmagnetic film.

Abstract: According to one embodiment, a magnetic recording head includes a main pole, a trailing shield opposing the main pole with a write gap therebetween, and a high-frequency oscillator between a distal end portion of the main pole and the trailing shield configured to produce a high-frequency magnetic field. The high-frequency oscillator includes a lower end surface facing the recording medium and an upper end surface substantially parallel to the lower end surface. The width of the lower end surface in a track-width direction is smaller than that of the upper end surface.

Abstract: According to one embodiment, a main pole of a recording head includes a first magnetic pole layer and a second magnetic pole layer laminated on the trailing side of the first magnetic pole layer. The first magnetic pole layer includes a tapered portion and a first tip portion. The second magnetic pole layer includes a tapered portion and a second tip portion. A width in a track direction of the second tip portion is smaller than that of the first tip portion. The high-frequency oscillator is between the second tip portion and the trailing shield and includes a width in the track direction substantially equal to the width in the track direction of the second tip portion, and a height of the first tip portion is taller than that of the second tip portion.

Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field, a return pole opposed to a trailing side of the main pole across a write gap and configured to return magnetic flux from the main pole, a coil configured to excite magnetic flux in the main pole, a spin-torque oscillator located between respective facing surfaces of the return pole and an end portion of the main pole on the recording-medium side and configured to produce a high-frequency magnetic field, a current source configured to apply current to the spin-torque oscillator through the return and main poles, and a nonmagnetic layer provided in at least one of the poles and extending from a facing surface of the at least one of the poles, which faces the spin-torque oscillator, in a direction across the facing surface.

Abstract: According to one embodiment, a perpendicular magnetic recording medium characterized by includes: a substrate; an undercoat layer formed on the substrate and made of a soft magnetic material; a recording layer formed on the undercoat layer and having an easy axis of magnetization in a direction that is approximately perpendicular to a surface of the perpendicular magnetic recording medium; and a protective layer which is formed on the recording layer and in which soft magnetic particles are mixed.

Abstract: According to one embodiment, a recording head includes a main pole formed of a soft magnetic material, a write shield pole formed of a soft magnetic material and on a trailing side of the main pole with a write gap, and side shields on both sides of the main pole in a track width direction and including nonmagnetic cavities formed of a nonmagnetic material in inner portions of the side shields. The side shields includes surfaces formed of a soft magnetic material and configured to be between a distal end portion of the main pole and the nonmagnetic cavity and between the recording medium and the nonmagnetic cavity.

Abstract: A magnetic disk device of an embodiment includes a magnetic disk, a magnetic head, a laser-beam-intensity control unit, a reproduced-signal detecting unit, and a magnetic-disk evaluating unit. The magnetic head reads a signal recorded in the magnetic disk, or performs magnetic recording while irradiating a laser beam onto the magnetic disk. The laser-beam-intensity control unit controls the intensity of the laser beam. The reproduced-signal detecting unit detects the signal read by the magnetic head. The magnetic-disk evaluating unit evaluates the signal read from the magnetic head, on the basis of a relation between a noise level detected from the signal read by the magnetic head, and the intensity of the laser beam.

Abstract: According to one embodiment, there is provided a magnetic recording head which records information on a magnetic recording medium, including an ABS surface, a near-field light generating unit, a heat conducting unit, and a heat absorbing unit. The ABS surface is opposed to the magnetic recording medium. The near-field light generating unit is disposed on the ABS surface. The heat conducting unit is formed by a heat conductor disposed in contact with the near-field light generating unit. The heat absorbing unit is disposed in contact with the heat conducting unit adjacently to the near-field light generating unit in a direction along the ABS surface.

Abstract: According to one embodiment, a magnetic head for perpendicular recording includes a first magnetic core includes a main pole configured to produce a recording magnetic field, and a return pole configured to reflux magnetic flux from the main pole to form a magnetic circuit in conjunction with the main pole, a first coil configured to excite magnetic flux in the magnetic circuit, side shields arranged individually on opposite sides of the main pole transversely relative to a track so as to be magnetically separated from the main pole and formed integrally with the return pole, a second magnetic core configured to form a physically closed magnetic path, a part of which comprises the return pole, and a second coil wound around the second magnetic core and configured to excite magnetic flux in the closed magnetic path.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing shield including a first connecting portion and a second connecting portion, and configured to form together with the main pole a first magnetic core, a leading shield including a first connecting portion connected to the main pole through a magnetic material and an end portion opposing to the end portion of the main pole through a non-magnetic material, and configured to form together with the main pole a second magnetic core, and first and second coils wound around the first and second magnetic cores, and a connection terminal configured to flow a current through the main pole, non-magnetic conductive layer, and trailing shield.

Abstract: According to one embodiment, a perpendicular magnetic recording head includes a main pole which generates a recording magnetic field, a return pole which forms a closed magnetic circuit for the recording magnetic field, and a side shield magnetically spaced from the main pole in a cross-track direction in which a point on a trailing edge of the side shield which is closest to the main pole is positioned on a leading side of a trailing edge of the main pole.

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: An example magnetic recording head includes a main magnetic pole containing a ferromagnetic layer and a main magnetic pole-magnetization fixing portion containing an anti-ferromagnetic layer in contact with at least one side surface of the main magnetic pole. A heater for the main magnetic pole is configured so as to include an oxide layer with a metal path therein embedded in or provided in the vicinity of the main magnetic pole-magnetization fixing portion and a pair of electrodes, provided in the vicinity of the oxide layer, for flowing a current parallel to a surface of a recording medium through the metal path. A magnetic field generator generates a magnetic field so as to direct a magnetization of the main magnetic pole in one direction.

Abstract: According to one embodiment, a perpendicular magnetic recording medium characterized by includes: a substrate; an undercoat layer formed on the substrate and made of a soft magnetic material; a recording layer formed on the undercoat layer and having an easy axis of magnetization in a direction that is approximately perpendicular to a surface of the perpendicular magnetic recording medium; and a protective layer which is formed on the recording layer and in which soft magnetic particles are mixed.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing core, a first coil wound around the trailing core, a leading core, and a second coil wound around the leading core. The trailing core includes a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole at a distance not more than double a track pitch of the recording medium. The leading core includes a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields with a width of 20 ?m or less transversely relative to the tracks and a connecting portion joined to the main pole in a position off the recording medium.

Abstract: An example magnetic recording head includes a main magnetic pole containing a ferromagnetic layer and a main magnetic pole-magnetization fixing portion containing an anti-ferromagnetic layer in contact with at least one side surface of the main magnetic pole. A heater for the main magnetic pole is configured so as to include an oxide layer with a metal path therein embedded in or provided in the vicinity of the main magnetic pole-magnetization fixing portion and a pair of electrodes, provided in the vicinity of the oxide layer, for flowing a current parallel to a surface of a recording medium through the metal path. A magnetic field generator generates a magnetic field so as to direct a magnetization of the main magnetic pole in one direction.

Abstract: According to one embodiment, a magnetic disk drive includes a magnetic disk to be subjected to perpendicular recording, a first pole core including a main pole configured to record signals on the magnetic disk, a first coil wound around the first pole core, a second pole core magnetically independent of the first pole core, tip ends of which are arranged on both sides of the main pole, a second coil wound around the second pole core, a read unit including an element configured to read data recorded on the magnetic disk, and a correction unit configured to correct a current phase difference between the first and second coils.

Abstract: According to one embodiment, a perpendicular magnetic recording head includes a main pole which generates a recording magnetic field, a return pole which forms a closed magnetic circuit for the recording magnetic field, and a side shield magnetically spaced from the main pole in a cross-track direction in which a point on a trailing edge of the side shield which is closest to the main pole is positioned on a leading side of a trailing edge of the main pole.