Magnetic sensor, magnetic head, and magnetic recording device

According to one embodiment, a magnetic sensor includes first to sixth shields, first and second magnetic layers, a first member, and first to fourth terminals. The first magnetic layer is provided between the first shield and the second shield. The first magnetic layer is between the third shield and the fourth shield in the second direction. The second magnetic layer is provided between the first magnetic layer and the second shield. The second magnetic layer is between the fifth shield and the sixth shield in the second direction. The second magnetic layer is electrically connected to the fifth shield and the sixth shield. The first member includes a first region and a second region. The first region is provided between the third shield and the first magnetic layer. The second region is provided between the first magnetic layer and the fourth shield.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-169280, filed on Oct. 21, 2022; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments of the invention generally relate to a magnetic sensor, a magnetic head, and a magnetic recording device.

BACKGROUND

There is a magnetic sensor using a magnetic layer. Information is recorded on a magnetic recording medium such as an HDD (Hard Disk Drive) using a magnetic head including the magnetic sensor. Magnetic sensors are desired to have improved resolution.

DETAILED DESCRIPTION

According to one embodiment, a magnetic sensor includes a first shield, a second shield, a third shield, a fourth shield, a fifth shield, a sixth shield, a first magnetic layer, a second magnetic layer, a first member, a first terminal, a second terminal, a third terminal, and a fourth terminal. The third shield is provided between the first shield and the second shield. The fourth shield is provided between the first shield and the second shield. A second direction from the third shield to the fourth shield crosses a first direction from the first shield to the second shield. The fifth shield is provided between the third shield and the second shield. The sixth shield is provided between the fourth shield and the second shield. A direction from the fifth shield to the sixth shield is along the second direction. The first magnetic layer is provided between the first shield and the second shield. The first magnetic layer is between the third shield and the fourth shield in the second direction. The second magnetic layer is provided between the first magnetic layer and the second shield. The second magnetic layer is between the fifth shield and the sixth shield in the second direction. The second magnetic layer is electrically connected to the fifth shield and the sixth shield. The first member includes a first region and a second region. The first region is provided between the third shield and the first magnetic layer. The second region is provided between the first magnetic layer and the fourth shield. The first terminal is electrically connected to the fifth shield. The second terminal is electrically connected to the sixth shield. The third terminal is electrically connected to the first magnetic layer. The fourth terminal electrically connected to the second magnetic layer.

In the specification and drawings, components similar to those described previously in an antecedent drawing are marked with like reference numerals, and a detailed description is omitted as appropriate.

First Embodiment

FIG.1andFIG.2are schematic cross-sectional views illustrating a magnetic sensor according to the first embodiment.

As shown inFIG.1, a magnetic sensor70A according to the embodiment includes a first shield41, a second shield42, a third shield43, a fourth shield44, a fifth shield45, a sixth shield46, and a first magnetic layer11, a second magnetic layer12, a first member31, a first terminal51, a second terminal52, a third terminal53and a fourth terminal54. In this example, the magnetic sensor70A includes a first conductive region21and a second conductive region22.

The third shield43is provided between the first shield41and the second shield42. The fourth shield44is provided between the first shield41and the second shield42. A second direction D2from the third shield43to the fourth shield44crosses a first direction D1from the first shield41to the second shield42.

The first direction D1is defined as an X-axis direction. One direction perpendicular to the X-axis direction is defined as a Y-axis direction. A direction perpendicular to the X-axis direction and the Y-axis direction is defined as a Z-axis direction. The second direction D2is, for example, the Y-axis direction.

The fifth shield45is provided between the third shield43and the second shield42. The sixth shield46is provided between the fourth shield44and the second shield42. A direction from the fifth shield45to the sixth shield46is along the second direction D2.

The first magnetic layer11is provided between the first shield41and the second shield42. The first magnetic layer11is located between the third shield43and the fourth shield44in the second direction D2. The first magnetic layer11is, for example, a ferromagnetic layer.

The second magnetic layer12is provided between the first magnetic layer11and the second shield42. The second magnetic layer12is located between the fifth shield45and the sixth shield46in the second direction D2. The second magnetic layer12is, for example, a ferromagnetic layer. The second magnetic layer12is electrically connected to, for example, the fifth shield45and the sixth shield46.

The first conductive region21is provided between the fifth shield45and the second magnetic layer12. The first conductive region21is electrically connected to the fifth shield45and the second magnetic layer12. The first conductive region21is non-magnetic. The first conductive region21may be, for example, a continuous layer. The first conductive region21may be mesh-like, for example. The first conductive region21may include, for example, a plurality of discontinuous island regions.

The second conductive region22is provided between the second magnetic layer12and the sixth shield46. The second conductive region22is electrically connected to the second magnetic layer12and the sixth shield46. The second conductive region22is non-magnetic. The second conductive region22may be, for example, a continuous layer. The second conductive region22may be mesh-like, for example. The second conductive region22may include, for example, a plurality of discontinuous island regions. The first conductive region21and the second conductive region22may be provided or omitted as required.

The first member31includes a first region31aand a second region31b. The first region31ais provided between the third shield43and the first magnetic layer11. The second region31bis provided between the first magnetic layer11and the fourth shield44.

The first terminal51is electrically connected to the fifth shield45. The second terminal52is electrically connected to the sixth shield46. The first terminal51is electrically connected to the second magnetic layer12via the fifth shield45(and the first conductive region21). The second terminal52is electrically connected to the second magnetic layer12via the sixth shield46(and the second conductive region22).

The third terminal53is electrically connected to the first magnetic layer11. For example, the third terminal53may be electrically connected to the first magnetic layer11via the first shield41. The fourth terminal54is electrically connected to the second magnetic layer12. For example, the fourth terminal54may be electrically connected to the second magnetic layer12via the second shield42.

By such a magnetic sensor70A, a detection target magnetic field can be detected with high spatial resolution. According to the embodiment, it is possible to provide a magnetic sensor capable of improving resolution.

For example, a first current i1can be supplied between the first terminal51and the second terminal52. For example, the magnetic sensor70A may include a first circuit75a. The first circuit75acan supply a first current i1between the first terminal51and the second terminal52. The first current i1flows through the second magnetic layer12. The first current i1includes a component along the second direction D2.

A voltage Vx between the third terminal53and the fourth terminal54can be detected in the magnetic sensor70A. For example, the magnetic sensor70A may include a second circuit75b. The second circuit75bcan detect a value corresponding to the voltage Vx between the third terminal53and the fourth terminal54.

The voltage Vx between the third terminal53and the fourth terminal54when the first current i1flows between the first terminal51and the second terminal52can change according to the detection target magnetic field.

The detection target magnetic field includes a component along a third direction D3. The third direction D3crosses a plane including the first direction D1and the second direction D2. The third direction D3is, for example, the Z-axis direction.

For example, in a first state, the detection target magnetic fields in the same direction are applied to both the first magnetic layer11and the second magnetic layer12. In a second state, the direction of the detection target magnetic field applied to the first magnetic layer11is opposite to the direction of the detection target magnetic field applied to the second magnetic layer12. In the magnetic sensor70A, the voltage Vx in the first state differs from the voltage Vx in the second state. By detecting the change in the voltage Vx, the first state and the second state can be distinguished and detected. For example, a change in the orientation of the detection target magnetic field in the region between the first magnetic layer11and the second magnetic layer12is detected. For example, it is possible to detect a change in the detection target magnetic field in a small area. According to embodiments, improving the resolution is possible.

In the magnetic sensor70A, the detection target magnetic field may be based on, for example, the orientation of magnetization recorded on a magnetic recording medium. For example, information recorded on the magnetic recording medium can be detected with high resolution.

In one example, a concentration of a first element in the first region31ais higher than a concentration of the first element in the first conductive region21, and a concentration of the first element in the second region31bis higher than a concentration of the first element in the second conductive region22. Alternatively, the first conductive region21and the second conductive region22do not include the first element. The first element includes at least one selected from the group consisting of oxygen and nitrogen.

For example, the first region31aand the second region31binclude oxide, nitride or oxynitride. In one example, at least one of the first region31aor the second region31bfurther includes a second element including at least one selected from the group consisting of Si, Al, Ta, Hf, and Mg. The first region31aand the second region31binclude, for example, at least one selected from the group consisting of silicon oxide, silicon nitride and aluminum oxide. The first region31aand the second region31bare, for example, insulative.

On the other hand, at least one of the first conductive region21or the second conductive region22includes at least one selected from the group consisting of Cu, Au, Ag, Pt, Al, Pd, Ta, Ru, Hf, W, Mo, Ir, Cr, Tb and Rh. At least one of the first conductive region21or the second conductive region22may include at least one selected from the group consisting of Au, Ta, Pt, Ru, Hf, W, Mo, Ir, Cr, Tb and Rh. In these materials, for example, the spin-orbit interaction is large. Unnecessary spin transfer is suppressed by using a material with a large spin-orbit interaction. The conductivity of the first conductive region21and the second conductive region22is higher than the conductivity of the first region31aand the second region31b.

For example, the direction of the magnetization of the second magnetic layer12is changed by the first current i1. The change in the direction of the magnetization direction of the second magnetic layer12includes, for example, a rotation component about the X-axis direction. On the other hand, the first current i1does not substantially flow through the first magnetic layer11. Therefore, the change in the orientation of the first magnetic layer11caused by the first current i1has small effect on the voltage Vx. It is considered that the difference in the voltage Vx is caused by such an action and the action of the difference between the first state and the second state with respect to the detection target magnetic field.

As shown inFIG.2, the first magnetic layer11has a first magnetization11M. The second magnetic layer12has a second magnetization12M. For example, the first magnetization11M and the second magnetization12M have components in the second direction D2. For example, the orientation of the first magnetization11M is opposite to the orientation of the second magnetization12M. For example, the first magnetic layer11may be antiferromagnetically coupled with the second magnetic layer12.

For example, when the detection target magnetic field in the first state is applied to the first magnetic layer11and the second magnetic layer12that are antiferromagnetically coupled, the change in the magnetization directions of these magnetic layers is small. On the other hand, when the detection target magnetic field in the second state is applied to the antiferromagnetically coupled first magnetic layer11and second magnetic layer12, the change in the magnetization directions of these magnetic layers is large. A change in the Z-axis component of magnetization due to a change in magnetization direction can be detected as a difference in change in voltage Vx based on the first current i1.

As shown inFIG.2, the third shield43has a third magnetization43M. The fourth shield44has a fourth magnetization44M. The fifth shield45has a fifth magnetization45M. The sixth shield46has a sixth magnetization46M. For example, the orientation of the third magnetization43M and the fourth magnetization44M may be the same as the orientation of the first magnetization11M. For example, the orientation of the fifth magnetization45M and the sixth magnetization46M may be the same as the orientation of the second magnetization12M.

As shown inFIG.1, the magnetic sensor70A may further include a first intermediate layer61, a second intermediate layer62and a third intermediate layer63. The first intermediate layer61is provided between the first magnetic layer11and the second magnetic layer12and is non-magnetic. The second intermediate layer62is provided between the third shield43and the fifth shield45and is non-magnetic. The third intermediate layer63is provided between the fourth shield44and the sixth shield46and is non-magnetic.

In one example, at least one of the first intermediate layer61, the second intermediate layer62, or the third intermediate layer63includes Ru. At this time, the thickness of the at least one of these layers along the first direction D1is not less than 0.1 nm and not more than 1.0 nm; or not less than 1.4 nm and not more than 2.2 nm; or not less than 2.6 nm and not more than 3.5 nm. By such a configuration it becomes easy to obtain antiferromagnetic coupling.

In another example, at least one of the first intermediate layer61, the second intermediate layer62or the third intermediate layer63includes Ir. At this time, the thickness of the at least one of these layers along the first directions D1is not less than 0.3 nm and not more than 0.8 nm; or not less than 1.1 nm and not more than 1.6 nm. By such a configuration, it becomes easy to obtain antiferromagnetic coupling. For example, it is easy to obtain antiferromagnetic coupling while suppressing leakage of the first current i1to the first magnetic layer11.

In the embodiment, a configuration corresponding to the peak (second peak, or first peak, etc.) of the RKKY (Ruderman-Kittel-Kasuya-Yosida) coupling may be applied to at least one of the first intermediate layer61, the second intermediate layer62, or the third intermediate layer63.

As shown inFIG.1, in the magnetic sensor70A, the first member31may further include a third region31cand a fourth region31d. The third region31cis provided between the first shield41and the third shield43. The fourth region31dis provided between the first shield41and the fourth shield44.

For example, the third region31cand the fourth region31dare insulative. For example, the first region31amay be continuous with the third region31c. The second region31bmay be continuous with the fourth region31d. The boundary between the first region31aand the third region31cmay be clear or unclear. The boundary between the second region31band the fourth region31dmay be clear or unclear. For example, the material of the third region31cmay be the same as the material of the first region31a. For example, the material of the fourth region31dmay be the same as the material of the second region31b.

As shown inFIG.1, the first member31may further include a fifth region31eand a sixth region31f. The fifth region31eis provided between the fifth shield45and the second shield42. The sixth region31fis provided between the sixth shield46and the second shield42. The fifth region31eand the sixth region31fare insulative.

As shown inFIG.1, a portion of the first region31amay be provided between the second intermediate layer62and the first intermediate layer61. A portion of the second region31bmay be provided between the first intermediate layer61and the third intermediate layer63.

As shown inFIG.1, the magnetic sensor70A may further include a fourth intermediate layer64and a fifth intermediate layer65. The fourth intermediate layer64is provided between the first shield41and the first magnetic layer11and is non-magnetic. The fifth intermediate layer65is provided between the second magnetic layer12and the second shield42and is non-magnetic.

The fourth intermediate layer64and the fifth intermediate layer65include, for example, at least one selected from the group consisting of Ti, Cu, Ru, Ta, Cr, Hf, and Mg. Thereby, it becomes easier for the first current i1to pass through the second magnetic layer12. The fourth intermediate layer64and the fifth intermediate layer65may include, for example, a nitride or an oxide of at least one selected from the group consisting of Ti, Cu, Ru, Ta, Cr, Hf, and Mg.

As shown inFIG.2, the thickness of the first conductive region21along the second direction D2is defined as a first conductive region thickness t21. The thickness of the second conductive region22along the second direction D2is defined as a second conductive region thickness t22. The first conductive region thickness t21may be, for example, not less than 1.0 nm and not more than 5.0 nm. The second conductive region thickness t22may be, for example, not less than 1.0 nm and not more than 5.0 nm. With such a thickness, for example, unnecessary spin transfer can be easily suppressed while obtaining magnetic interaction with the shield.

As shown inFIG.2, the thickness of the first magnetic layer11along the first direction D1is defined as a first magnetic layer thickness t11. The thickness of the second magnetic layer12along the first direction D1is defined as a second magnetic layer thickness t12. In the embodiment, the first magnetic layer thickness t11is not less than 2.0 nm and not more than 10.0 nm. The second magnetic layer thickness t12is not less than 2.0 nm and not more than 10.0 nm.

In the magnetic sensor70A, the stacked body provided between the first shield41and the second shield42includes the first magnetic layer11, the first intermediate layer61and the second magnetic layer12. The thickness of the stacked boy is thin. It is easy to obtain high resolution.

For example, the direction of magnetization of the second magnetic layer12changes depending on the detection target magnetic field. The change in the voltage Vx due to the change in the magnetization direction in the state where the first current i1is supplied may be based on, for example, the Anomalous Hall Effect (AHE). For example, the second magnetic layer12has an anomalous Hall effect.

For example, the second magnetic layer12includes at least one selected from the group consisting of CoMnGa, CoMnAl, and FePt. In such materials, a large anomalous Hall effect can easily be obtained. For example, it is easy to obtain a large detection output. CoMnGa and CoMnAl are, for example, Heusler alloy materials.

In the embodiment, the first current i1is suppressed from flowing through the first magnetic layer11by the first region31aand the second region31b. Therefore, even if the first magnetic layer11includes a material with a large anomalous Hall effect, the anomalous Hall effect is suppressed. The material of the first magnetic layer11may be the same as the material of the second magnetic layer12.

In the embodiment, the anomalous Hall effect may be small in the first magnetic layer11. Even if a part of the first current i1flows through the first magnetic layer11, adverse effects can be suppressed. For example, the material of the first magnetic layer11is preferably different from the material of the second magnetic layer12. For example, the first magnetic layer11includes at least one selected from the group consisting of Co, Ni, and Fe. The first magnetic layer11may include, for example, at least one selected from the group consisting of CoFe, CoNiFe, NiFe, CoZrNb, FeN, FeSi, and FeAlSi. The first magnetic layer11may include, for example, a soft magnetic material having a relatively high saturation magnetic flux density and magnetic anisotropy in the in-plane direction. The anomalous Hall effect is relatively small in the above materials. For example, it is easy to increase the change (difference) in the voltage Vx between the first state and the second state.

As described below, the thickness of the first magnetic layer11(first magnetic layer thickness t11) may be different from the thickness of the second magnetic layer12(second magnetic layer thickness t12).

FIG.3is a schematic cross-sectional view illustrating the magnetic sensor according to the first embodiment.

As shown inFIG.3, in a magnetic sensor70B according to the embodiment, the thickness of the first magnetic layer11(first magnetic layer thickness t11) is thinner than the thickness of the second magnetic layer12(second magnetic layer thickness t12). Except for this, the configuration of the magnetic sensor70B may be the same as the configuration of the magnetic sensor70A.

By the first magnetic layer thickness t11being thin, the influence of the anomalous Hall effect in the first magnetic layer11is further suppressed. For example, it is easy to increase the change (difference) in the voltage Vx between the first state and the second state.

In the magnetic sensor70B, the second magnetic layer12may include at least one selected from the group consisting of Co, Ni, and Fe, for example. The second magnetic layer12may include, for example, at least one selected from the group consisting of CoMnGa, CoMnAl, and FePt. CoMnGa and CoMnAl are Heusler alloy materials. The material of the first magnetic layer11may be different from the material of the second magnetic layer12. For example, the first magnetic layer11may include at least one selected from the group consisting of Co, Ni, and Fe. The first magnetic layer11may include, for example, at least one selected from the group consisting of CoFe, CoNiFe, NiFe, CoZrNb, FeN, FeSi, and FeAlSi.

Second Embodiment

FIG.4is a schematic perspective view illustrating a magnetic head and a magnetic recording device according to the second embodiment.

As shown inFIG.4, a magnetic head110according to the embodiment includes a reproducing section70. The reproducing section70includes a magnetic sensor (magnetic sensor70A or magnetic sensor70B) according to the first embodiment. The magnetic head110is used with magnetic recording medium80. In this example, the magnetic head110includes a recording section90. Information is recorded on the magnetic recording medium80by the recording section90of the magnetic head110. Information recorded on the magnetic recording medium80is reproduced by the reproducing section70.

The magnetic recording medium80includes, for example, a medium substrate82and a magnetic recording layer81provided on the medium substrate82. The magnetization83of the magnetic recording layer81is controlled by the recording section90. The recording section90includes, for example, a first magnetic pole91and a second magnetic pole92. The first magnetic pole91is, for example, the main magnetic pole. The second magnetic pole92is, for example, a trailing shield. The recording section90may include a recording section element93. The recording section element93may include a magnetic field control element, a high frequency oscillation element, or the like. The recording section element93may be omitted.

The reproducing section70includes, for example, a first reproducing magnetic shield72a, a second reproducing magnetic shield72b, and a magnetic reproducing element71. The magnetic reproducing element71is provided between the first reproducing magnetic shield72aand the second reproducing magnetic shield72b. The magnetic reproducing element71can output a signal corresponding to the magnetization83of the magnetic recording layer81.

The first reproducing magnetic shield72acorresponds to, for example, the first shield41(seeFIG.1). The second reproducing magnetic shield72bcorresponds to, for example, the second shield42(seeFIG.1). The magnetic reproducing element71includes a stacked boy including the first magnetic layer11, the second magnetic layer12and the first intermediate layer61. InFIG.4, the third shield43, the fourth shield44, the fifth shield45, the sixth shield46, etc. are omitted.

As shown inFIG.4, the magnetic recording medium80moves relative to the magnetic head110in a medium movement direction85. Information corresponding to the magnetization83of the magnetic recording layer81is controlled at an arbitrary position by the magnetic head110. Information corresponding to the magnetization83of the magnetic recording layer81is reproduced at an arbitrary position by the magnetic head110.

FIG.5is a schematic perspective view illustrating a portion of the magnetic recording device according to the embodiment.

FIG.5illustrates a head slider.

The magnetic head110is provided on a head slider159. The head slider159includes, for example, Al2O3/TIC and the like. The head slider159moves relative to the magnetic recording medium while floating or contacting the magnetic recording medium.

The head slider159includes, for example, an air inflow side159A and an air outflow side159B. The magnetic head110is arranged on the side surface of the air outflow side159B of the head slider159. As a result, the magnetic head110moves relative to the magnetic recording medium while floating or contacting the magnetic recording medium.

FIG.6is a schematic perspective view illustrating a magnetic recording device according to the embodiment.

FIGS.7A and7Bare schematic perspective views illustrating a portion of the magnetic recording device according to the embodiment.

The magnetic recording device may be a magnetic recording/reproducing device. As shown inFIG.6, in the magnetic recording device150according to the embodiment, a rotary actuator is used. A recording medium disk180is mounted on a spindle motor180M. The recording medium disk180is rotated in the direction of an arrow AR by the spindle motor180M. The spindle motor180M responds to a control signal from the drive device controller. The magnetic recording device150according to the embodiment may include multiple recording medium disks180. The magnetic recording device150may include a recording medium181. The recording medium181is, for example, an SSD (Solid State Drive). As the recording medium181, for example, a non-volatile memory such as a flash memory is used. For example, the magnetic recording device150may be a hybrid HDD (Hard Disk Drive).

The head slider159records and reproduces the information to be recorded on the recording medium disk180. The head slider159is provided at the tip of the thin film suspension154. A magnetic head according to the embodiment is provided near the tip of the head slider159.

When the recording medium disk180rotates, the pressing pressure by a suspension154and the pressure generated on the medium facing surface (ABS) of the head slider159are balanced. The distance between the media facing surface of the head slider159and the surface of the recording medium disk180is a predetermined fly height. In the embodiment, the head slider159may contact the recording medium disk180. For example, a contact-sliding type may be applied.

The suspension154is connected to one end of an arm155(e.g., an actuator arm). The arm155includes, for example, a bobbin portion and the like. The bobbin portion holds a drive coil. A voice coil motor156is provided at the other end of the arm155. The voice coil motor156is a kind of linear motor. The voice coil motor156includes, for example, a drive coil and a magnetic circuit. The drive coil is wound around the bobbin portion of the arm155. The magnetic circuit includes a permanent magnet and an opposed yoke. A drive coil is provided between the permanent magnet and the opposing yoke. The suspension154has one end and the other end. The magnetic head is provided at one end of the suspension154. The arm155is connected to the other end of the suspension154.

The arm155is held by a ball bearing. Ball bearings are provided at two locations above and below the bearing part157. The arm155can be rotated and slid by the voice coil motor156. The magnetic head can be moved to an arbitrary position on the recording medium disk180.

FIG.7Aillustrates a partial configuration of the magnetic recording device and is an enlarged perspective view of a head stack assembly160.

FIG.7Bis a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA)158that is a portion of the head stack assembly160.

As shown inFIG.7A, the head stack assembly160includes the bearing part157, the head gimbal assembly158, and a support frame161. The head gimbal assembly158extends from the bearing part157. The support frame161extends from the bearing part157. The extending direction of the support frame161is opposite to the extending direction of the head gimbal assembly158. The support frame161supports a coil162of the voice coil motor156.

As shown inFIG.7B, the head gimbal assembly158includes the arm155extending from the bearing part157and the suspension154extending from the arm155.

The head slider159is provided at the tip of the suspension154. The head slider159is provided with the magnetic head according to the embodiment.

The magnetic head assembly (head gimbal assembly)158according to the embodiment includes the magnetic head according to the embodiment, the head slider159provided with the magnetic head, the suspension154, and the arm155. The head slider159is provided at one end of the suspension154. The arm155is connected to the other end of the suspension154.

The suspension154includes, for example, lead wires (not shown) for recording and reproducing signals. The suspension154may include, for example, a lead wire (not shown) for a heater for adjusting the fly height. The suspension154may include, for example, a lead wire (not shown) for a spin transfer torque oscillator. These lead wires and multiple electrodes provided on the magnetic head are electrically connected.

The magnetic recording device150is provided with a signal processor190. The signal processor190records and reproduces a signal on a magnetic recording medium using a magnetic head. The input/output lines of the signal processor190are connected to, for example, the electrode pads of the head gimbal assembly158, and are electrically connected to the magnetic head.

The magnetic recording device150according to the embodiment includes the magnetic recording medium, the magnetic head according to the embodiment, a movable part, a position controller, and the signal processor. The movable part is relatively movable in a state where the magnetic recording medium and the magnetic head are separated or brought into contact with each other. The position controller aligns the magnetic head with a predetermined recording position on the magnetic recording medium. The signal processor records and reproduces a signal on a magnetic recording medium using a magnetic head.

For example, as the above-mentioned magnetic recording medium, the recording medium disk180is used. The movable part includes, for example, the head slider159. The position controller includes, for example, the head gimbal assembly158.

The embodiments may include the following configurations (e.g., technical proposals).

A magnetic sensor, comprising:a first shield;a second shield;a third shield provided between the first shield and the second shield;a fourth shield provided between the first shield and the second shield, a second direction from the third shield to the fourth shield crossing a first direction from the first shield to the second shield;a fifth shield provided between the third shield and the second shield;a sixth shield provided between the fourth shield and the second shield, a direction from the fifth shield to the sixth shield being along the second direction;a first magnetic layer provided between the first shield and the second shield, the first magnetic layer being between the third shield and the fourth shield in the second direction;a second magnetic layer provided between the first magnetic layer and the second shield, the second magnetic layer being between the fifth shield and the sixth shield in the second direction, the second magnetic layer being electrically connected to the fifth shield and the sixth shield;a first member including a first region and a second region, the first region being provided between the third shield and the first magnetic layer, the second region being provided between the first magnetic layer and the fourth shield;a first terminal electrically connected to the fifth shield;a second terminal electrically connected to the sixth shield;a third terminal electrically connected to the first magnetic layer; anda fourth terminal electrically connected to the second magnetic layer.
Configuration 2

The sensor according to Configuration 1, whereina voltage between the third terminal and the fourth terminal when a first current flows between the first terminal and the second terminal is configured to be changed according to a detection target magnetic field.
Configuration 3

The sensor according to Configuration 1 or 2, further comprising:a first conductive region provided between the fifth shield and the second magnetic layer, the first conductive region being electrically connected to the fifth shield and the second magnetic layer, the first conductive region being non-magnetic; anda second conductive region provided between the second magnetic layer and the sixth shield, the second conductive region being electrically connected to the second magnetic layer and the sixth shield, the second conductive region being non-magnetic,a concentration of a first element in the first region being higher than a concentration of the first element in the first conductive region, and a concentration of the first element in the second region being higher than a concentration of the first element in the second conductive region; or the first conductive region and the second conductive region not including the first element, andthe first element including at least one selected from the group consisting of oxygen and nitrogen.
Configuration 4

The sensor according to Configuration 3, whereinat least one of the first region or the second region further includes a second element including at least one selected from the group consisting of Si, Al, Ta, Hf, and Mg.
Configuration 5

The sensor according to Configuration 3 or 4, whereinat least one of the first conductive region or the second conductive region includes at least one selected from the group consisting of Au, Ta, Pt, Ru, Hf, W, Mo, Ir, Cr, Tb, and Rh.
Configuration 6

The sensor according to any one of Configurations 1-5, further comprising:a first intermediate layer provided between the first magnetic layer and the second magnetic layer, the first intermediate layer being non-magnetic;a second intermediate layer provided between the third shield and the fifth shield, the second intermediate layer being non-magnetic; anda third intermediate layer provided between the fourth shield and the sixth shield, the third intermediate layer non-magnetic,at least one of the first intermediate layer, the second intermediate layer, or the third intermediate layer including Ru, anda thickness of the at least one along the first directions being not less than 0.1 nm and not more than 1.0 nm; or not less than 1.4 nm and not more than 2.2 nm; or not less than 2.6 nm and not more than 3.5 nm.
Configuration 7

The sensor according to any one of Configurations 1-5, further comprising:a first intermediate layer provided between the first magnetic layer and the second magnetic layer, the first intermediate layer being non-magnetic;a second intermediate layer provided between the third shield and the fifth shield, the second intermediate layer being non-magnetic; anda third intermediate layer provided between the fourth shield and the sixth shield, the third intermediate layer non-magnetic,at least one of the first intermediate layer, the second intermediate layer, or the third intermediate layer including Ir, anda thickness of the at least one along the first directions being not less than 0.3 nm and not more than 0.8 nm; or not less than 1.1 nm and no more than 1.6 nm.
Configuration 8

The sensor according to any one of Configurations 1-5, whereinthe first magnetic layer is antiferromagnetically coupled with the second magnetic layer.
Configuration 9

The sensor according to any one of Configurations 1-8, whereinthe second magnetic layer includes at least one selected from the group consisting of CoMnGa, CoMnAl, and FePt.
Configuration 10

The sensor according to any one of Configurations 1-9, whereina material of the first magnetic layer is different from a material of the second magnetic layer.
Configuration 11

The sensor according to Configuration 9 or 10, whereina first magnetic layer thickness along the first direction of the first magnetic layer is thinner than a second magnetic layer thickness along the first direction of the second magnetic layer.
Configuration 12

The sensor according to any one of Configurations 1-11, whereinthe first member further includes:a third region provided between the first shield and the third shield; anda fourth region provided between the first shield and the fourth shield, andthe third region and the fourth region are insulative.
Configuration 13

The sensor according to Configuration 12, whereinthe first region is continuous with the third region, andthe second region is continuous with the fourth region.
Configuration 14

The sensor according to any one of Configurations 1-13, whereinthe first member further includes:a fifth region provided between the fifth shield and the second shield; anda sixth region provided between the sixth shield and the second shield, andthe fifth region and the sixth region are insulative.
Configuration 15

The sensor according to any one of Configurations 1-14, further comprising:a fourth intermediate layer provided between the first shield and the first magnetic layer, the fourth intermediate layer being non-magnetic; anda fifth intermediate layer provided between the second magnetic layer and the second shield, the fifth intermediate layer being non-magnetic, andthe fourth intermediate layer and the fifth intermediate layer including at least one selected from the group consisting of Ti, Cu, Ru, Ta, Cr, Hf, and Mg.
Configuration 16

The sensor according to any one of Configurations 3-5, whereina first conductive region thickness along the second direction of the first conductive region is not less than 1.0 nm and not more than 5.0 nm, anda second conductive region thickness along the second direction of the second conductive region is not less than 1.0 nm and not more than 5.0 nm.
Configuration 17

A magnetic sensor, comprising:a first shield;a second shield;a third shield provided between the first shield and the second shield;a fourth shield provided between the first shield and the second shield, a second direction from the third shield to the fourth shield crossing a first direction from the first shield to the second shield;a fifth shield provided between the third shield and the second shield;a sixth shield provided between the fourth shield and the second shield, a direction from the fifth shield to the sixth shield being along the second direction;a first magnetic layer provided between the first shield and the second shield, the first magnetic layer being between the third shield and the fourth shield in the second direction;a second magnetic layer provided between the first magnetic layer and the second shield, the second magnetic layer being between the fifth shield and the sixth shield in the second direction, the second magnetic layer being electrically connected to the fifth shield and the sixth shield, the second magnetic layer being antiferromagnetically coupled with the first magnetic layer;a first member including a first region and a second region, the first region being provided between the third shield and the first magnetic layer, the second region being provided between the first magnetic layer and the fourth shield;a first terminal electrically connected to the fifth shield;a second terminal electrically connected to the sixth shield;a third terminal electrically connected to the first magnetic layer; anda fourth terminal electrically connected to the second magnetic layer.
Configuration 18

The sensor according to any one of Configurations 1-17, whereinthe second magnetic layer has an Anomalous Hall Effect.
Configuration 19

A magnetic head, comprising:the magnetic sensor according to any one of Configurations 1-18
Configuration 20

A magnetic recording device, comprising:the magnetic head according to Configuration 19; anda magnetic recording medium,the magnetic sensor being configured to reproduce information recorded on the magnetic recording medium.

According to the embodiments, it is possible to provide a magnetic sensor, a magnetic head, and a magnetic recording device capable of improving resolution.

Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in magnetic sensors, magnetic heads and magnetic recording devices such as shields, magnetic layers, conductive regions, members, intermediate layers and terminals, etc., from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained.

Moreover, all magnetic sensors, magnetic heads, and magnetic recording devices practicable by an appropriate design modification by one skilled in the art based on the magnetic sensors, magnetic heads, and magnetic recording devices described above as embodiments of the invention also are within the scope of the invention to the extent that the spirit of the invention is included.