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185 results about "Spin torque oscillators" patented technology

Magnetic head and magnetic recording device

It is made possible to restrict the variation of the oscillation frequency of a spin torque oscillator placed in the vicinity of the recording magnetic pole. A magnetic head includes: a recording magnetic pole to generate a recording magnetic field; a spin torque oscillator formed in the vicinity of the recording magnetic pole; and a magnetic field applying unit configured to apply a magnetic field to the spin torque oscillator. The magnetic field applied to the spin torque oscillator by the magnetic field applying unit is perpendicular to a recording magnetic field generated from the recording magnetic pole.
Owner:KK TOSHIBA

Magnetic recording head, magnetic head assembly, magnetic recording apparatus, and magnetic recording method

A magnetic recording head includes a first magnetic pole, a second magnetic pole, a spin torque oscillator, a first coil, a second coil, and a third coil. The first magnetic pole applies a recording magnetic field to a magnetic recording medium. The second magnetic pole is provided parallel to the first magnetic pole. At least a portion of the spin torque oscillator is provided between the first magnetic pole and the second magnetic pole. The first coil magnetizes the first magnetic pole. A current is passed through the second coil independently of the first coil. A current is passed through the third coil independently of both the first coil and the second coil.
Owner:KK TOSHIBA

Magnetic head and magnetic recording device

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.
Owner:KK TOSHIBA

Perpendicular magnetic recording write head and system with improved spin torque oscillator for microwave-assisted magnetic recording

A microwave-assisted magnetic recording (MAMR) write head and system has a spin-torque oscillator (STO) located between the write pole of the write head and a trailing shield that alters the write field from the write pole. The STO is a stack of layers whose planes lie generally parallel to the X-Y plane of an X-Y-Z coordinate system, the stack including a ferromagnetic polarizer layer, a free ferromagnetic layer, and a nonmagnetic electrically conductive spacer between the polarizer layer and the free layer. In the presence of the write field from the write pole the polarizer layer has its magnetization oriented at an angle between 20 and 80 degrees, preferably between 30 and 70 degrees, with the Z-axis. In the presence of a direct electrical current through the STO stack, the free layer magnetization rotates or precesses about the Z-axis with a non-zero angle to the Z-axis.
Owner:WESTERN DIGITAL TECH INC

Magnetic recording head with spin torque oscillator layers satisfying width, thickness and angle relationship formulas

A magnetic recording head has a main magnetic pole that generates a recording magnetic field applied on a magnetic recording medium from an end surface that is one portion of an air bearing surface facing the magnetic recording medium; a trailing shield provided on the trailing side of the main magnetic pole with a write gap interposed therebetween; and a spin torque oscillator that is provided in the write gap to be interposed between the main magnetic pole and the trailing shield and that generates a magnetic field that exerts an interaction on the recording magnetic field applied on the magnetic recording medium.
Owner:TDK CORPARATION

Spin-torque oscillator, magnetic head including the spin-torque oscillator, and magnetic recording and reproducing apparatus

It is made possible to to provide a spin-torque oscillator that has a high Q value and a high output. A spin-torque oscillator includes: an oscillating field generating unit configured to generate an oscillating field; and a magnetoresistive element including a magnetoresistive effect film including a first magnetization pinned layer of which a magnetization direction is pinned, a first magnetization free layer of which a magnetization direction oscillates with the oscillating field, and a first spacer layer interposed between the first magnetization pinned layer and the first magnetization free layer.
Owner:KK TOSHIBA

Magnetic head, magnetic recording method and apparatus for controlling magnetic head with spin torque oscillator in a disk drive

A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.
Owner:HITACHI LTD

Spin-torque oscillator (STO) with magnetically damped free layer

A spin-torque oscillator (STO) has increased magnetic damping of the oscillating free ferromagnetic layer. The Gilbert magnetic damping parameter (α) is at least 0.05, and preferably greater than 0.05. The free layer may be a any type of conventional ferromagnetic material, but contains one or more damping elements as a dopant. The damping element is selected from the group consisting of Pt, Pd and the 15 lanthanide elements. The free layer damping may also be increased by a damping layer adjacent the free layer. One type of damping layer may be an antiferromagnetic material, like a Mn alloy. As a modification to the antiferromagnetic damping layer, a bilayer damping layer may be formed of the antiferromagnetic layer and a nonmagnetic metal electrically conductive separation layer between the free layer and the antiferromagnetic layer. Another type of damping layer may be one formed of one or more of the elements selected from Pt, Pd and the lanthanides.
Owner:WESTERN DIGITAL TECH INC

Magnetic recording head and magnetic recording device

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.
Owner:KK TOSHIBA

Apparatus for assisting write operation using high frequency magnetic field in disk drive

According to one embodiment, a disk drive having a spin torque oscillator and designed to perform high frequency assisted writing. The disk drive has a magnetic disk, a magnetic head, a coil, and a drive current controller. The drive current controller controls a drive current to supply to the spin torque oscillator. To record data magnetically in the disk, the drive current controller supplies to the spin torque oscillator the drive current that changes in synchronism with the polarity inversion of the recording current supplied to the coil, which excites the recording magnetic pole of the magnetic head.
Owner:KK TOSHIBA

Magnetic head assembly and magnetic recording/reproducing apparatus

ActiveUS20100007996A1Reduce the write magnetic fieldNanomagnetismNanoinformaticsInter layerSpin torque oscillators
It is made possible to reduce the write magnetic field generated from the main magnetic pole toward the spin torque oscillator, so as to reduce the variation in the oscillation characteristics of the spin torque oscillator, and reduce the current required for oscillation. The magnetic head assembly includes: a recording magnetic pole; a spin torque oscillator that has first and second magnetic layers, and an intermediate layer interposed between the first and second magnetic layers, the spin torque oscillator generating a high-frequency magnetic field by applying a current between the first and second magnetic layers; and a third magnetic layer that is placed adjacent to at least part of a side face of the second magnetic layer.
Owner:KK TOSHIBA

Perpendicular magnetic recording write head and system with improved spin torque oscillator for microwave-assisted magnetic recording

A microwave-assisted magnetic recording (MAMR) write head and system has a spin-torque oscillator (STO) located between the write pole of the write head and a trailing shield that alters the write field from the write pole. The STO is a stack of layers whose planes lie generally parallel to the X-Y plane of an X-Y-Z coordinate system, the stack including a ferromagnetic polarizer layer, a free ferromagnetic layer, and a nonmagnetic electrically conductive spacer between the polarizer layer and the free layer. In the presence of the write field from the write pole the polarizer layer has its magnetization oriented at an angle between 20 and 80 degrees, preferably between 30 and 70 degrees, with the Z-axis. In the presence of a direct electrical current through the STO stack, the free layer magnetization rotates or precesses about the Z-axis with a non-zero angle to the Z-axis.
Owner:WESTERN DIGITAL TECH INC

Magnetic head assembly and magnetic recording apparatus

A magnetic head assembly includes a magnetic recording head, a head slider, a suspension and an actuator arm. The magnetic recording head includes: a main magnetic pole; an adjustment magnetic pole provided together with the main magnetic pole; a spin torque oscillator; a main magnetic pole coil being wound around the main magnetic pole; and an adjustment magnetic pole coil being wound around the adjustment magnetic pole. At least part of the spin torque oscillator is provided between the main magnetic pole and the adjustment magnetic pole. A way of winding of the adjustment magnetic pole coil is different from a way of winding of the main magnetic pole coil. The magnetic recording head is mounted on the head slider. The head slider is mounted on one end of the suspension. The actuator arm is connected to the other end of the suspension.
Owner:KK TOSHIBA

Magnetic recording head and magnetic recording device

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.
Owner:KK TOSHIBA

Apparatus for assisting write operation using high frequency magnetic field in disk drive

According to one embodiment, a disk drive having a spin torque oscillator and designed to perform high frequency assisted writing. The disk drive has a magnetic disk, a magnetic head, a coil, and a drive current controller. The drive current controller controls a drive current to supply to the spin torque oscillator. To record data magnetically in the disk, the drive current controller supplies to the spin torque oscillator the drive current that changes in synchronism with the polarity inversion of the recording current supplied to the coil, which excites the recording magnetic pole of the magnetic head.
Owner:KK TOSHIBA

Three-terminal spin-torque oscillator (STO)

A spin-torque oscillator (STO) has a single free ferromagnetic layer that forms part of both a giant magnetoresistance (GMR) structure with a nonmagnetic conductive spacer layer and a tunneling magnetoresistance (TMR) structure with a tunnel barrier layer. The STO has three electrical terminals that connect to electrical circuitry that provides a spin-torque excitation current through the conductive spacer layer and a lesser sense current through the tunnel barrier layer. When the STO is used as a magnetic field sensor, the excitation current causes the magnetization of the free layer to oscillate at a fixed base frequency in the absence of an external magnetic field. A detector coupled to the sense current detects shifts in the free layer magnetization oscillation frequency from the base frequency in response to external magnetic fields.
Owner:WESTERN DIGITAL TECH INC

Spin torque oscillator, magnetic recording head, magnetic head assembly and magnetic recording apparatus

A spin torque oscillator includes a first magnetic layer, a second magnetic layer and a first nonmagnetic layer. The first magnetic layer includes a magnetic film of a magnetic material with a body-centered cubic (bcc) structure and an oriented {110} plane of the body-centered cubic structure, the oriented {110} plane being oriented substantially parallel to a principal plane of the magnetic film. The first nonmagnetic layer is disposed between the first magnetic layer and the second magnetic layer. In addition, a magnetic moment in the magnetic film precesses around an axis substantially parallel to the principal plane. Furthermore, a magnetic field is applied in a direction substantially perpendicular to the principal plane, and a current is passed perpendicularly to the principal plane.
Owner:KK TOSHIBA

Modified field generation layer for microwave assisted magnetic recording

A spin torque oscillator is described in which the conventional Field Generation Layer (FGL) is replaced by a bilayer, one of whose members exhibits perpendicular magnetic anisotropy while the other exhibits conventional in-plane anisotropy. Provided the layer with the perpendicular anisotropy is the one that is closest to the spacer layer, the device is able to generate microwaves at current densities as low as 1×108 A / cm2.
Owner:HEADWAY TECH INC

Spin-torque oscillator, magnetic head including the spin-torque oscillator, and magnetic recording and reproducing apparatus

It is made possible to provide a spin-torque oscillator that has a high Q value and a high output. A spin-torque oscillator includes: an oscillating field generating unit configured to generate an oscillating field; and a magnetoresistive element including a magnetoresistive effect film including a first magnetization pinned layer of which a magnetization direction is pinned, a first magnetization free layer of which a magnetization direction oscillates with the oscillating field, and a first spacer layer interposed between the first magnetization pinned layer and the first magnetization free layer.
Owner:KK TOSHIBA

Perpendicular magnetic recording write head with spin torque oscillator for fast switching of write pole magnetization

A perpendicular magnetic recording write head that a write pole, an electrically conductive coil coupled to the write pole for generating magnetic flux in the write pole in the presence of electrical write current, and a spin torque oscillator (STO) that injects auxiliary magnetic flux to the write pole in a direction generally orthogonal to the write pole to facilitate magnetization switching of the write pole. The STO comprises a stack of layers including electrodes, a pinned ferromagnetic layer having a fixed, a free ferromagnetic layer having a magnetization free to rotate, and a nonmagnetic spacer layer between the pinned and free layers. The free layer may be oriented either substantially orthogonal to the write pole or substantially parallel to the write pole, in which latter embodiment a flux guide may be located between the free layer and the write pole for directing the auxiliary magnetic flux from the free layer to the write pole.
Owner:WESTERN DIGITAL TECH INC

Circuit for phase locked oscillators

The present invention pertains to a circuit comprising a DC current source and at least two spin torque oscillators, the at least two spin torque oscillators being electrically coupled to each other and to the DC current source. A circuit comprising phase shifting means is connected in such a way as to cause a phase shift between current and voltage through the spin torque oscillators. An advantage of the present invention is that the controlled phase shift significantly increases the tolerance for deviating anisotropy fields, which makes manufacturing of spin torque oscillator devices much more feasible in practice.FIG. 2, wherein the DC current source comprises phase shifting means.
Owner:PERSSON JOHAN +2

Spin Torque Oscillator Sensor

A spin torque oscillation magnetoresistive sensor for measuring a magnetic field. The sensor uses a change in precessional oscillation frequency of a magnetization of a magnetic layer to determine the magnitude of a magnetic field. The sensor can include a magnetic free layer, a magnetic pinned layer and a non-magnetic layer sandwiched therebetween. Circuitry is connected with these layers to induce an electrical current through the layers. Spin polarization of electrons traveling through the device causes a spin torque induced precession of the magnetization of one or more of the layers. The frequency of this oscillation modulates in response to a magnetic field. The modulation of the oscillation frequency can be measured to detect the presence of the magnetic field, and determine its magnitude.
Owner:WESTERN DIGITAL TECH INC

Magnetic recording head with protruding spin torque oscillator

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.
Owner:KK TOSHIBA

Magnetic head, magnetic recording method and apparatus for controlling magnetic head with spin torque oscillator in a disk drive

A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.
Owner:HITACHI LTD

Pile spin-torque oscillator with AF-mode oscillation for generating high AC-field in microwave-assisted magnetic recording

The present disclosure generally relates to a structure for a perpendicular microwave-assisted magnetic recording head used in a magnetic disk drive. A first spin-torque oscillator and a second spin-torque oscillator are positioned between the main pole of a recording head and a trailing shield, and are separated by a spin torque shield layer. The first spin-torque oscillator comprises a first magnetic layer, a first non-magnetic interlayer, and a second magnetic layer. The second spin-torque oscillator comprises a third magnetic layer, a second non-magnetic interlayer, and a fourth magnetic layer. An applied current is adapted to flow in a direction from the second magnetic layer to the first magnetic layer, and from the fourth magnetic layer to the third magnetic layer.
Owner:WESTERN DIGITAL TECH INC
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