Abstract:
At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.
Abstract:
A microwave assisted magnetic head includes a main magnetic pole; a trailing shield; and a spin torque oscillator provided between the main magnetic pole and the trailing shield. The spin torque oscillator has a first end surface configuring a part of an air bearing surface, a second end surface facing the main magnetic pole, and a third end surface facing the first end surface, the first angle θ1 made by the first end surface and the second end surface is smaller than the second angle θ2 formed by the second end surface and the third end surface, and the second angle θ2 is 80 to 100 degrees.
Abstract:
A thermal assisted magnetic recording head of the present invention has an air bearing surface (ABS) opposite to a magnetic recording medium, a core that can propagate laser light as propagating light, a plasmon generator that includes a generator front end surface facing the ABS, and a main pole that faces the ABS and emits magnetic flux to the magnetic recording medium. The plasmon generator is opposite to a part of the core and extends to the generator front surface, is coupled with a portion of the propagating light that propagates through the core in the surface plasmon mode to generate a surface plasmon, propagates the surface plasmon to the generator front end surface, and generates near-field light (NF light) at the generator front end surface to irradiate the NF light to the magnetic recording medium. The ABS has a protrusion that is closer to the leading side than the generator front end surface in the down track direction, and that protrudes more toward the magnetic recording medium than the generator front end surface upon operation of the thermal assisted magnetic recording head.
Abstract:
A base multilayer body is made by laminating a seed layer and a buffer layer in respective order. The seed layer is an alloy layer containing tantalum (Ta) and at least one type of other metal, and having an amorphous structure or a microcrystal structure. The buffer layer is an alloy layer having a [001] plane orientation hexagonal close-packed structure and containing at least one type of a group VI metal and at least one type of a group IX metal in the periodic table. With this configuration, a magnetic layer providing a desired magnetic characteristic(s) can be laminated on the thinned base multilayer body.
Abstract:
While a plurality of drive currents for flying height setting with current values smaller than a tentative optimum drive current are supplied to a light source, respectively, heater power is supplied to a heater part, and touch down of a thermally-assisted magnetic recording head is detected. Tentative optimum heater power is determined based on a correlation between the heater power when the touch down is detected and each drive current for flying height setting. The tentative optimum drive current is supplied to the light source part; the tentative optimum heater power is supplied to the heater part; a reference signal is recorded in a magnetic recording medium; and flying height of the thermally-assisted magnetic recording head is set by determining whether or not the reference signal is recorded with the desired signal intensity.
Abstract:
A thermal assisted magnetic recording head has a magnetic head slider having an air bearing surface that is opposite to a magnetic recording medium, a core that can propagate laser light as propagating light, a plasmon generator that includes a generator front end surface facing the air bearing surface, and a main pole facing the air bearing surface, and a laser light generator that supplies the laser light to the core. The plasmon generator generates near-field light (NF light) at the generator front end surface to heat the magnetic recording medium. The main pole includes a main pole end surface that faces the air bearing surface and that is positioned in the vicinity of the generator front end surface, and emits a magnetic flux to the magnetic recording medium from the main pole end surface. At least a portion of the laser light that is not coupled with the plasmon generator thermally deforms the air bearing surface so that a part of the air bearing surface positioned closer to the leading side than the generator front end surface and the main pole end surface in the down track direction protrudes toward the magnetic recording medium.
Abstract:
A plasmon generator of a thermally-assisted magnetic recording head has a first configuration member having a near-field light generation end surface at an ABS, and a second configuration member being in contact with main magnetic pole, and terminating at a front end portion of a slope positioned at the position recessed from the ABS. An end part of a separator layer, which is interposed between the main magnetic pole and the first configuration member, on a side opposite to the ABS is at a position more recessed from the air bearing surface than the front end portion of the slope of the second configuration member.
Abstract:
A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an S/N ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.