Abstract: A hard-disk drive having a structurally efficient magnetic head slider utilizes a MAMR-based spin torque oscillator (STO) for head-disk contact detection and for flying height sensing. Contact detection and spacing estimation techniques consider the nominal temperature difference, and thus different criteria, between read and write operations.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) erasure prevention for microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). A first voltage is applied to an STO element in the MAMR head at the time of write operation. A second voltage is applied to the STO element at the time of read operation, or not write operation, to prevent STO erasure otherwise resulting from remnant magnetization of STO at the time of read operation.

Abstract: Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.

Abstract: The present disclosure generally relates to a high-frequency oscillator for use in a recording device having a microwave-assisted magnetic recording head. The microwave-assisted magnetic recording head achieves a large assist effect by using an extended spin torque oscillator disposed between a main magnetic pole and a pole opposite the main magnetic pole. The spin torque oscillator obtains a strong high-frequency magnetic field and comprises a first non-magnetic spin scatterer, a reference layer, a first non-magnetic spin transfer layer, a first magnetic field generating layer, a second non-magnetic spin transfer layer, a second magnetic field generating layer, and a second non-magnetic spin scatterer. The spin torque oscillator has a drive current flowing though in the direction from the first magnetic field generating layer to the reference layer.

Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO and a current switching system electrically coupled to the STO. The current switching system can be used to optimize the STO frequency by changing the STO bias polarity, i.e., by changing the direction of the current flowing to the STO. As a result, the difference between the STO frequency and the magnetic media frequency is minimized, which improves recording capability of the MAMR head.

Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first magnetic layer, a second magnetic layer and an interlayer disposed between the first and second magnetic layers. One of the first and second magnetic layers is made of a negative polarization material while the other magnetic layer is made of a positive polarization material. As a result, the magnetizations in the first and second magnetic layers are in the same direction when in oscillation, which suppresses the partial cancellation of the magnetizations in the first and second magnetic layers and strengthens the AC magnetic field.

Abstract: Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first magnetic layer, a second magnetic layer and an interlayer disposed between the first and second magnetic layers. One of the first and second magnetic layers is made of a negative polarization material while the other magnetic layer is made of a positive polarization material. As a result, the magnetizations in the first and second magnetic layers are in the same direction when in oscillation, which suppresses the partial cancellation of the magnetizations in the first and second magnetic layers and strengthens the AC magnetic field.

Abstract: Embodiments of the present invention help to reduce mag-noise in a magnetoresistive head without deterioration in reproduced output and improve the signal/noise ratio (SNR) of the magnetoresistive head. According to one embodiment, the magnetoresistive head uses a synthetic ferri free layer and it is arranged such that the magnetic field which is applied to an end of a free layer with smaller film thickness and saturation magnetization in the track width direction by a coupling field is larger than the magnetic field which is applied to it by a bias layer.

Abstract: Embodiments of the present invention generally include magnetoresistive heads, such as read heads, having a sensor structure and side shields disposed adjacent to the sensor structure. The distance between the side shields and the sensor structure increase in a direction from an ABS in the off-track direction. The magnetoresistive heads may include tapered surfaces on the side shields or sensor structure, or may include stepped surfaces on the side shields or sensor structure.

Abstract: The present disclosure generally relates to a high-frequency oscillator for use in a recording device having a microwave-assisted magnetic recording head. The microwave-assisted magnetic recording head achieves a large assist effect by using an extended spin torque oscillator disposed between a main magnetic pole and a pole opposite the main magnetic pole. The spin torque oscillator obtains a strong high-frequency magnetic field and comprises a first non-magnetic spin scatterer, a reference layer, a first non-magnetic spin transfer layer, a first magnetic field generating layer, a second non-magnetic spin transfer layer, a second magnetic field generating layer, and a second non-magnetic spin scatterer. The spin torque oscillator has a drive current flowing though in the direction from the first magnetic field generating layer to the reference layer.

Abstract: Embodiments of the present invention generally relate to a microwave assisted magnetic recording (MAMR) head. The MAMR head includes a main pole, a trailing shield, and a spin torque oscillator (STO) disposed between the main pole and the trailing shield. The STO is recessed from an air bearing surface.

Abstract: The present disclosure generally relates to the structure of a perpendicular magnetic write head for use in a magnetic disk drive. A shingled-microwave-assisted magnetic recording head for use in a high-areal-density hard disk drive comprises a trailing shield, a flare-shaped main pole, one or more side shields, a spin torque oscillator, and two asymmetric side gaps, where one side gap has a smaller width than the other side gap. The spin torque oscillator shares a first continuous edge with the main pole on a side adjacent the side gap having the smaller width and shares a second continuous edge adjacent a media facing surface. The angle of the spin torque oscillator and the main pole formed by the media facing surface and the narrow side gap is greater than about 90°.

Abstract: The embodiments disclosed generally relate to a read head sensor in a magnetic recording head. The read head sensor comprises side shields in addition to the upper and lower shields. The upper shield sensor is a multilayer structure with antiferromagnetic coupling. The side shield is a multilayer structure whereby a lower magnetic layer is separated from an upper magnetic layer. The upper magnetic layer is ferromagnetically coupled to a bottom layer of the upper shield. The bias direction of the read head sensor is antiparallel to the bottom layer of the upper shield.

Abstract: The embodiments disclosed generally relate to a read head sensor in a magnetic recording head. The read head sensor comprises side shields in addition to the upper and lower shields. The upper shield sensor is a multilayer structure with antiferromagnetic coupling. The side shield is a multilayer structure whereby a lower magnetic layer is separated from an upper magnetic layer. The upper magnetic layer is ferromagnetically coupled to a bottom layer of the upper shield. The bias direction of the read head sensor is antiparallel to the bottom layer of the upper shield.

Abstract: The embodiments disclosed generally relate to an STO structure for a magnetic head. The STO structure has an FGL having a greater thickness than the SPL. The SPL may have multiple layers. In one embodiment, a MAMR head comprises a main pole; a trailing shield; and an STO coupled between the main pole and the trailing shield. The STO includes: a first magnetic layer having a first thickness; a non-magnetic spacer layer coupled to the first magnetic layer; and a second magnetic layer having a second thickness and coupled to the non-magnetic spacer layer, wherein the first thickness is greater than the second thickness, wherein a current is charged from the first magnetic layer to the second magnetic layer, and wherein a vertical magnetic anisotropy field of the second magnetic film is less than 0 kOe.

Abstract: Approaches to improving the signal-to-noise ratio in a microwave-assisted magnetic recording hard disk drive over the entire region from the inner diameter to the outer diameter of the disk, especially in the context of shingled magnetic recording, include a narrower side gap on the side opposing a spin torque oscillator offset direction than the side gap in the offset direction, thereby increasing the gradient of the recording magnetic field in the cross-track direction and reducing the track edge noise of the recording pattern. Embodiments include use of a side shield on the side opposing the offset direction that has a higher saturation magnetization than the side shield on the side in the offset direction, thereby further increasing the gradient of the recording magnetic field in the cross-track direction.

Abstract: Embodiments described herein generally relate to a magnetic read head wherein read sensitivity distribution is made asymmetric in the off-track direction. The method of making the magnetic head is also disclosed. The read head may comprise a magneto-resistive effect element with an asymmetric structure around the element in the off-track direction and the read sensitivity profile in the off-track direction may also be asymmetric.

Abstract: 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.

Abstract: A microwave-assisted magnetic recording (MAMR) head according to one embodiment includes a main magnetic pole adapted to generate a writing magnetic field when current is applied to a write coil; a trailing shield positioned, at an air bearing surface (ABS), in a trailing direction from the main magnetic pole; and a field generation layer (FGL) positioned, at the ABS, between the main magnetic pole and the trailing shield, wherein either a portion of the main magnetic pole closer to the FGL or a portion of the trailing shield closer to the FGL is adapted to act as a spin polarization layer.

Abstract: Approaches to improving the signal-to-noise ratio in a microwave-assisted magnetic recording hard disk drive over the entire region from the inner diameter to the outer diameter of the disk, especially in the context of shingled magnetic recording, include a narrower side gap on the side opposing a spin torque oscillator offset direction than the side gap in the offset direction, thereby increasing the gradient of the recording magnetic field in the cross-track direction and reducing the track edge noise of the recording pattern. Embodiments include use of a side shield on the side opposing the offset direction that has a higher saturation magnetization than the side shield on the side in the offset direction, thereby further increasing the gradient of the recording magnetic field in the cross-track direction.