Magnetic head with stacked body configurations and magnetic recording device including the same

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body. The first magnetic pole includes a first face and a second face crossing the first face. The second face includes a first face region continuous with the first face. The second magnetic pole includes a third face and a fourth face crossing the third face, and the fourth face includes a second face region that is continuous with the third face. The first face and the third face are along the third direction. The stacked body is provided between the first face region and the second face region. The stacked body includes a first magnetic layer, and a second magnetic layer provided between the first magnetic layer and the second face region. The second magnetic layer includes a second magnetic layer face facing the second face region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-126244, filed on Aug. 8, 2022; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a magnetic head and a magnetic recording device.

BACKGROUND

Information is recorded on a magnetic recording medium such as an HDD (Hard Disk Drive) using a magnetic head. It is desired to improve the recording density in the magnetic head and the magnetic recording device.

DETAILED DESCRIPTION

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body. The first magnetic pole includes a first face and a second face crossing the first face. The second face includes a first face region continuous with the first face. The second magnetic pole includes a third face and a fourth face crossing the third face. The fourth face includes a second face region. The second face region is continuous with the third face. A direction from the first face region to the second face region is along a first direction. The first face region and the second face region are along a second direction and a third direction. The third direction crosses a plane including the first direction and the second direction. The first face and the third face are along the third direction. The stacked body is provided between the first face region and the second face region. The stacked body includes a first magnetic layer, and a second magnetic layer provided between the first magnetic layer and the second face region. The second magnetic layer includes a second magnetic layer face facing the second face region. A width ratio of a second width of the second magnetic layer face along the third direction to a first width of the first face region along the third direction is not less than 0.25 and not more than 0.92.

First Embodiment

FIGS.1A and1Bare schematic views illustrating a magnetic head according to a first embodiment.

FIG.1Ais a cross-sectional view.FIG.1Bis a plan view seen from arrow AR1inFIG.1A.

FIG.2is a schematic cross-sectional view illustrating the magnetic recording device according to the first embodiment.

As shown inFIG.2, a magnetic recording device210according to the embodiment includes a magnetic head110and an electric circuit20D. The magnetic recording device210may include a magnetic recording medium80. At least a recording operation is performed in the magnetic recording device210. In the recording operation, information is recorded on the magnetic recording medium80using the magnetic head110.

The magnetic head110includes a recording part60. As will be described later, the magnetic head110may include a reproducing part. The recording part60includes a first magnetic pole31, a second magnetic pole32and a stacked body20. The stacked body20is provided between the first magnetic pole31and the second magnetic pole32.

For example, the first magnetic pole31and the second magnetic pole32form a magnetic circuit. The first magnetic pole31is, for example, a main pole. The second magnetic pole32is, for example, a trailing shield.

A direction from the magnetic recording medium80to the magnetic head110is defined as a Z-axis direction. One direction perpendicular to the Z-axis direction is defined as an X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is defined as a Y-axis direction. The Z-axis direction corresponds to, for example, the height direction. The X-axis direction corresponds to, for example, the down-track direction. The Y-axis direction corresponds to, for example, the cross-track direction. The magnetic recording medium80and the magnetic head110move relatively along the down-track direction. A magnetic field (recording magnetic field) generated from the magnetic head110is applied to a desired position of the magnetic recording medium80. Magnetization at a desired position of the magnetic recording medium80is controlled in a direction according to the recording magnetic field. Information is thus recorded on the magnetic recording medium80. For example, perpendicular magnetic recording is performed.

As shown inFIG.2, a coil30cis provided. In this example, a portion of coil30cis located between first magnetic pole31and second magnetic pole32. In this example, a shield33is provided. The first magnetic pole31is located between the shield33and the second magnetic pole32in the X-axis direction. Another portion of coil30cis located between shield33and first pole31. An insulating portion30iis provided between these multiple elements. The shield33is, for example, a leading shield. The magnetic head110may also include side shields (not shown).

As shown inFIG.2, a recording current Iw is supplied from the recording circuit30D to the coil30c. A recording magnetic field corresponding to the recording current Iw is applied to the magnetic recording medium80from the first magnetic pole31.

As shown inFIG.2, the first magnetic pole31includes a medium facing surface30F. The medium facing surface30F is, for example, an ABS (Air Bearing Surface). The medium facing surface30F faces the magnetic recording medium80, for example. The medium facing surface30F spreads, for example, along the X-Y plane.

As shown inFIG.2, an electric circuit20D is electrically connected to the stacked body20. In this example, the stacked body20is electrically connected to the first magnetic pole31and the second magnetic pole32. In the magnetic head110, a first terminal T1and a second terminal T2are provided. The first terminal T1is electrically connected to the stacked body20via a first wiring W1and the first magnetic pole31. The second terminal T2is electrically connected to the stacked body20via a second wiring W2and the second magnetic pole32. For example, a current (for example, direct current) is supplied to the stacked body20from the electric circuit20D.

As shown inFIG.1B, a current ic is supplied to such the stacked body. The current ic is supplied, for example, from the electric circuit20D described above. As shown inFIG.1B, in this example, the current ic has an orientation from the second magnetic layer22to the first magnetic layer21. As shown inFIG.1B, an electron flow je associated with the current ic has an orientation from the first magnetic layer21to the second magnetic layer22. The orientation of the current ic is from the second magnetic pole32to the first magnetic pole31.

For example, the magnetization of the magnetic layers included in the stacked body20oscillates when the current ic of a threshold value or more flows through the stacked body20. The stacked body20functions, for example, as an STO (Spin-Torque Oscillator). Along with the oscillation, an alternating magnetic field (for example, a high frequency magnetic field) is generated from the stacked body20. The alternating magnetic field generated by the stacked body20is applied to the magnetic recording medium80to assist the writing to the magnetic recording medium80. For example, MAMR (Microwave Assisted Magnetic Recording) can be performed.

As shown inFIGS.1A and1B, in this example, the stacked body20includes a third magnetic layer23, a fourth magnetic layer24, a first non-magnetic layer41, and a second non-magnetic layer42, a third non-magnetic layer43, a fourth non-magnetic layer44and a fifth non-magnetic layer45. The insulating portion30iis omitted inFIGS.1A and1B.

The first magnetic pole31includes a first face F1and a second face F2. The second face F2crosses the first face F1. The second face F2includes a first face region r1. The first face region r1is continuous with the first face F1. The first face F1corresponds to the medium facing surface30F.

The second magnetic pole32includes a third face F3and a fourth face F4. The fourth face F4crosses the third face F3. The fourth face F4includes a second face region r2. The second face region r2is continuous with the third face F3. The third face F3is, for example, along a plane that includes the first face F1.

A direction from the first face region r1to the second face region r2is along a first direction D1. The first face region r1and the second face region r2are along a second direction D2and a third direction D3. The third direction D3crosses a plane including the first direction D1and the second direction D2. The first face F1and the third face F3are along the third direction D3. The stacked body20is provided between the first face region r1and the second face region r2.

The third direction D3is along the Y-axis direction, for example. The first direction D1may be along the X-axis direction. The first direction D1is along the gap direction (the direction of the gap between the first magnetic pole31and the second magnetic pole32). The first direction D1may be inclined with respect to the X-axis direction. The first direction D1corresponds to the stacking direction of the stacked body20. The second direction D2may correspond to the height direction. The second direction D2may be inclined with respect to the Z-axis direction.

The stacked body20includes a first magnetic layer21and a second magnetic layer22. The second magnetic layer22is provided between the first magnetic layer21and the second face region r2.

As shown inFIGS.1A and1B, the second magnetic layer22includes a second magnetic layer face22F. The second magnetic layer face22F faces the second face region r2. The second magnetic layer face22F is a face on a side of the second face region r2.

As shown inFIG.1B, a width along the third direction D3of the first face region r1is defined as a first width w1. A width along the third direction D3of the second magnetic layer face22F is defined as a second width w2. In the embodiment, a width ratio (w2/w1) of the second width w2to the first width w1is not less than 0.25 and not more than 0.92 or less. Thereby, the alternating magnetic field is efficiently generated as described later. Efficient MAMR can be performed. According to the embodiments, it is possible to provide a magnetic head capable of improving the recording density.

As shown inFIG.1A, the second face F2may further include a third face region r3. The first face region r1is between the first face F1and the third face region r3. The third face region r3are along the second direction D2and the third direction D3. The third face region r3is substantially parallel to the first face region r1. The third face region r3is continuous with the first face region r1.

As shown inFIG.1A, the fourth face F4further includes a fourth face region r4and a fifth face region r5. A direction from the third face region r3to the fourth face region r4is along the first direction D1. The fourth face region r4is along the second direction D2and the third direction D3. The fourth face region r4is substantially parallel to the second face region r2.

A distance along the first direction D1between the first surface region r1and the second surface region r2is defined as a first distance d1.

A distance along the first direction D1between the first face region r1and the second face region r2is defined as a first distance d1. A distance along the first direction D1between the third face region r3and the fourth face region r4is defined as a second distance d2. The first distance d1is shorter than the second distance d2.

The fifth face region r5is between the second face region r2and the fourth face region r4. A plane including the fifth face region r5crosses a plane including the third face region r3and a plane including the fourth face region r4.

The second magnetic pole32includes a crossing position32pof the plane including the fifth face region r5and the plane including the fourth face region r4. In one example, the crossing position32pis on the fourth face F4. In one example, the crossing position32pis inside the second magnetic pole32. The length along the second direction D2between the crossing position32pand the third face F3is defined as a first length L1. The first length L1corresponds to the effective height of the second magnetic pole32, for example.

A length along the second direction D2of the second magnetic layer face22F is defined as a second length L2. The second length L2corresponds to, for example, the effective height of the second magnetic layer face22F. A ratio (L2/L1) of the second length L2to the first length L1is defined as a length ratio. In the embodiment, for example, the ratio is preferably not less than 0.1 and not more than 0.85. Thereby, the alternating magnetic field is efficiently generated as described later. Efficient MAMR can be implemented. According to the embodiments, it is possible to provide a magnetic head capable of improving the recording density.

As shown inFIGS.1A and1B, in the magnetic head110, the stacked body20may include, for example, the third magnetic layer23, the fourth magnetic layer24, the first non-magnetic layer41, the second non-magnetic layer42, the third non-magnetic layer43, the fourth non-magnetic layer44and the fifth non-magnetic layer45. The third magnetic layer23is provided between the first magnetic pole31and the first magnetic layer21. The fourth magnetic layer24is provided between the first magnetic layer21and the second magnetic layer22.

The first non-magnetic layer41is provided between the first magnetic pole31and the third magnetic layer23. The second non-magnetic layer42is provided between the third magnetic layer23and the first magnetic layer21. The third non-magnetic layer43is provided between the first magnetic layer21and the fourth magnetic layer24. The fourth non-magnetic layer44is provided between the fourth magnetic layer24and the second magnetic layer22. The fifth non-magnetic layer45is provided between the second magnetic layer22and the second magnetic pole32.

As shown inFIG.1B, a thickness of the first magnetic layer21along the first direction D1is defined as a first thickness t1. A thickness of the second magnetic layer22along the first direction D1is defined as a second thickness t2. A thickness of the third magnetic layer23along the first direction D1is defined as a third thickness t3. A thickness of the fourth magnetic layer24along the first direction D1is defined as a fourth thickness t4.

In the magnetic head110, the first thickness t1is thicker than the third thickness t3. The second thickness t2is thicker than the fourth thickness t4. The third thickness t3is, for example, 0.7 times or less the first thickness t1. The fourth thickness t4is, for example, 0.75 times or less the second thickness t2. For example, the third thickness t3may be 0.1 times or more the first thickness t1. For example, the fourth thickness t4may be 0.1 times or more the second thickness t2.

For example, the first magnetic layer21and the second magnetic layer22may function, for example, as oscillation layers. The third magnetic layer23and the fourth magnetic layer24may function, for example, as spin injection layers. At least one of the first magnetic layer21, the second magnetic layer22, the third magnetic layer23, and the fourth magnetic layer24includes, for example, at least one selected from the group consisting of Fe, Co, and Ni.

In one example of the magnetic head110, the first thickness t1is, for example, not less than 3 nm and not more than 15 nm. The first thickness t1may be, for example, not less than 5 nm and not more than 15 nm. The second thickness t2is, for example, not less than 5 nm and not more than 15 nm. The third thickness t3is, for example, not less than 0.5 nm and not more than 5 nm. The fourth thickness t4is, for example, not less than 0.5 nm and not more than 8 nm.

In the magnetic head110, the first non-magnetic layer41include at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, for example. The second non-magnetic layer42includes, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. For example, the third non-magnetic layer43includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and the fourth non-magnetic layer44includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W. Alternatively, for example, the third non-magnetic layer43includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, and the fourth non-magnetic layer44includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer45includes, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.

As shown inFIG.1B, a thickness of the first non-magnetic layer41along the first direction D1is defined as a first non-magnetic layer thickness t41. A thickness of the second non-magnetic layer42along the first direction D1is defined as a second non-magnetic layer thickness t42. A thickness of the third non-magnetic layer43along the first direction D1is defined as a third non-magnetic layer thickness t43. A thickness of the fourth non-magnetic layer44along the first direction D1is defined as a fourth non-magnetic layer thickness t44. A thickness of the fifth non-magnetic layer45along the first direction D1is defined as a fifth non-magnetic layer thickness t45.

In one example of the magnetic head110, the first non-magnetic layer thickness t41is, for example, not less than 2 nm and not more than 8 nm. The second non-magnetic layer thickness t42is, for example, not less than 1 nm and not more than 5 nm. The third non-magnetic layer thickness t43is, for example, not less than 1 nm and not more than 8 nm. The fourth non-magnetic layer thickness t44is, for example, not less than 1 nm and not more than 8 nm. The fifth non-magnetic layer thickness t45is, for example, not less than 1 nm and not more than 8 nm.

As shown inFIG.1A, the first magnetic layer21has a face on a side of the second magnetic layer22. A length of the face of the first magnetic layer21along the second direction D2is defined as a third length L3. In embodiments, the third length L3is longer than the second length L2. As shown inFIG.1B, the first magnetic layer21has a face on a side of the second magnetic layer22. A width of the face of the first magnetic layer21along the third direction D3is defined as a third width w3. In embodiments, the third width w3is wider than the second width w2. For example, the size of the first magnetic layer21is larger than the size of the second magnetic layer22. For example, the resistance of the first magnetic layer21is lower than the resistance of the second magnetic layer22.

Example of simulation results for the characteristics of the magnetic head110will be described below.

FIG.3is a graph illustrating characteristics of the magnetic head.

The horizontal axis ofFIG.3is the width ratio Rw1. As already explained, the width ratio Rw1is the ratio (w2/w1) of the second width w2to the first width w1. The first width w1is the width along the third direction D3of the first face region r1. The second width w2is the width along the third direction D3of the second magnetic layer face22F. The vertical axis inFIG.3is a parameter P1relating to the magnitude of alternating resistance change in the second magnetic layer22. The parameter P1is normalized. When the parameter P1is large, the alternating change in resistance in the second magnetic layer22is large. When the alternating change in resistance is large, alternating power accompanying the alternating change in resistance acts on the first magnetic layer21. Thereby, the alternating magnetic field is efficiently generated from the first magnetic layer21.

The simulation conditions are as follows. The first width w1is 60 nm. The second width w2is changed. The first length L1is 50 nm. The second length L2is 35 nm. The first thickness t1is 5 nm. The second thickness t2is 5 nm. The third thickness t3is 2 nm. The fourth thickness t4is 2 nm. The first non-magnetic layer thickness t41is 4 nm. The second non-magnetic layer thickness t42is 2 nm. The third non-magnetic layer thickness t43is 2 nm. The fourth non-magnetic layer thickness t44is 3 nm. The fifth non-magnetic layer thickness t45is 2 nm.

As shown inFIG.3, the parameter P1of 0.5 or more is obtained when the width ratio Rw1is not less than 0.25 and not more than 0.92 or less. In the embodiment, the width ratio Rw1is preferably not less than 0.25 and not more than 0.92. When the width ratio Rw1is not less than 0.25 and more than 0.92, the alternating power accompanying the resistance change increases. The alternating magnetic field is effectively generated by the action of the alternating power.

The width ratio Rw1may be not less than 0.4 and not more than 0.85. The parameter P1greater than or equal to 0.75 is obtained. The alternating magnetic field is generated more effectively.

The reason why a large parameter P1is obtained when the width ratio Rw1is not less than 0.25 and not more than 0.92 is considered to be caused by, for example, an increase in a component parallel to the second magnetic layer face22F of the magnetic field applied to the second magnetic layer22from the first magnetic pole31and the second magnetic pole32. It is considered that the alternating change of the resistances of the resistances in the second magnetic layer22at the interface becomes large. The interface is, for example, the second magnetic layer face22F.

FIG.4is a graph illustrating characteristics of the magnetic head.

The horizontal axis ofFIG.4is the length ratio RL1. As already explained, the length ratio RL1is the ratio (L2/L1) of the second length L2to the first length L1. The second length L2is the length (height) along the second direction D2of the second magnetic layer face22F. The first length L1is the length (height) along the second direction D2between the crossing position32pand the third face F3. The vertical axis inFIG.4is the parameter P1.

As shown inFIG.4, the parameter P1of 0.5 or more is obtained when the length ratio RL1is not less than 0.1 and not more than 0.85. Thereby, the alternating power associated with the resistance change is increased. The alternating magnetic field is effectively generated by acting on the alternating power. In the embodiment, the length ratio RL1is preferably not less than 0.1 and not more than 0.85. When the length ratio RL1is not less than 0.1 and not more than 0.85, the alternating power accompanying resistance change increases. The alternating magnetic field is effectively generated by the action of the alternating power.

The length ratio RL1may be not less than 0.2 and not more than 0.72. The parameter P1greater than or equal to 0.75 is obtained. The alternating magnetic field is generated more effectively.

The reason why the large parameter P1is obtained when the length ratio RL1is not less than 0.1 and not more than 0.85 is considered to be caused by, for example, an increase in a component parallel to the second magnetic layer face22F of the magnetic field applied from the first magnetic pole31and the second magnetic pole32to the second magnetic layer22. For example, among the resistances in the second magnetic layer22, it is considered that the alternating change of the resistance at the interface becomes large. The interface is, for example, the second magnetic layer face22F. The reason why a larger parameter P1is obtained when the length ratio RL1is not less than 0.2 and not more than 0.7 is considered to be due to a further increase in a component parallel to the second magnetic layer face22F of the magnetic field applied from the first magnetic pole31and the second magnetic pole32to the second magnetic layer22.

FIG.5is a schematic diagram illustrating the operation of the magnetic head in the first embodiment.

As shown inFIG.5, the resistance between the first terminal T1and the second terminal T2changes alternately when the current ic of a threshold value or more flows through the stacked body20. By the alternating resistance change, the alternating power Pa1is generated. The alternating power Pa1is applied (superimposed) to the current ic. For example, the magnetization22M of the second magnetic layer22oscillates, and the resistance of the second magnetic layer22changes alternately. The magnetization21M of the first magnetic layer21oscillates when the current ic of the threshold value or higher flows into the first magnetic layer21. The alternating magnetic field Ha1is generated from the first magnetic layer21. The alternating power Pa1based on the resistance change of the second magnetic layer22acts on the first magnetic layer21. The frequency of the alternating magnetic field Ha1can substantially match the frequency of the alternating power Pa1. For example, the alternating magnetic field Ha1and the alternating electric power Pa1are synchronized. For example, a current magnetic field may be generated by the alternating power Pa1, and the generated current magnetic field may be superimposed on the alternating magnetic field Ha1.

The alternating electric power Pa1generated by the second magnetic layer22effectively acts on the first magnetic layer21to generate the alternating magnetic field Ha1with high efficiency. For example, by the action of the alternating power Pa1, the oscillation of the magnetization21M of the first magnetic layer21is stabilized, and the alternating magnetic field Ha1is generated with high efficiency. By obtaining efficiently resistance change in the second magnetic layer22, the alternating electric power Pa1of high intensity can act on the first magnetic layer21.

In the embodiment, the width ratio Rw1is in an appropriate range to provide an efficient resistance change. When the length ratio RL1is in an appropriate range, an efficient resistance change can be obtained.

Thus, in the magnetic head110, for example, when the current ic flows through the stacked body20, the alternating magnetic field Ha1is generated from the stacked body20, and the alternating power Pa1is generated in the stacked body20. For example, the absolute value of the difference between a first frequency of the alternating magnetic field Ha1and a second frequency of the alternating power Pa1is 0.25 times or less of the first frequency. The absolute value of the difference may be 0.1 times or less of the first frequency.

In one example, at least a part of the alternating power Pa1is generated in the second magnetic layer22. In one example, at least a part of the alternating magnetic field Ha1is generated from the first magnetic layer21. For example, it is considered that at least a part of the alternating power Pa1is generated from the magnetic layer having a small size. For example, it is considered that at least a part of the alternating magnetic field Ha1is generated from the magnetic layer having a large size.

The magnetic recording device210includes the magnetic head110and the electric circuit20D. The magnetic head110includes the first magnetic pole31, the second magnetic pole32, and the stacked body20. The stacked body20is provided between the first magnetic pole31and the second magnetic pole32. The electric circuit20D is configured to supply current to the stacked body20. The stacked body20includes the first magnetic layer21and the second magnetic layer22provided between the first magnetic layer21and the second magnetic pole32. When the current ic flows through the stacked body20, the alternating magnetic field Ha1is generated from the stacked body20, and the alternating electric power Pa1is generated in the stacked body20.

In the magnetic recording device210, the absolute value of the difference between the first frequency of the alternating magnetic field Ha1and the second frequency of the alternating power Pa1is 0.25 times or less of the first frequency. The absolute value of the difference may be 0.1 times or less of the first frequency. The first frequency is, for example, from 15 GHz to 50 GHz. The alternating magnetic field Ha1of the first frequency is applied to the magnetic recording medium80, and the MAMR is effectively performed.

FIGS.6to8are schematic plan views illustrating magnetic heads according to the first embodiment.

These are plan views viewed from arrow AR1inFIG.1A.

As shown inFIG.6, in a magnetic head110aaccording to the embodiment, the width (For example, the first width w1of the first face region r1) of the first magnetic pole31may be wider than the width of the stacked body20. The width of the stacked body20is, for example, the maximum length of the stacked body20in the third direction D3.

As shown inFIG.7, in a magnetic head110baccording to the embodiment, the width (For example, the first width w1of the first face region r1) of the first magnetic pole31may be smaller than the width of the stacked body20. The width of the stacked body20is, for example, the maximum length of the stacked body20in the third direction D3.

As shown inFIG.8, in a magnetic head110caccording to the embodiment, the position of the first magnetic pole31in the third direction D3may be shifted from the position of the stacked body20in the third direction D3. The position of the first magnetic pole31in the third direction D3may be, for example, a position of the center of the first magnetic pole31in the third direction D3. The position of the stacked body20in the third direction D3may be, for example, a position of the center of the stacked body20in the third direction D3.

The configuration of the magnetic head110a, the magnetic head110b, and the magnetic head110cother than the above may be the same as that of the magnetic head110. A magnetic head capable of improving the recording density can be provided

FIGS.9A and9Bare schematic views illustrating the magnetic head according to the first embodiment.

FIG.9Ais a cross-sectional view.FIG.9Bis a plan view seen from arrow AR1inFIG.9A. As shown inFIGS.9A and9B, a magnetic head111according to the embodiment also includes the first magnetic pole31, the second magnetic pole32and the stacked body20. The configuration of the stacked body20in the magnetic head111is different from the configuration of the stacked body20in the magnetic head110. Except for this, the configuration of the magnetic head111may be the same as the configuration of the magnetic head110.

In the magnetic head111, the stacked body20includes the first magnetic layer21, the second magnetic layer22, the third magnetic layer23, the fourth magnetic layer24, the first non-magnetic layer41, the second non-magnetic layer42, the third non-magnetic layer43, the fourth non-magnetic layer44, and the fifth non-magnetic layer45. The second magnetic layer22is provided between the first magnetic layer21and the second magnetic pole32. The third magnetic layer23is provided between the first magnetic layer21and the second magnetic layer22. The fourth magnetic layer24is provided between the second magnetic layer22and the second magnetic pole32. The first non-magnetic layer41is provided between the first magnetic pole31and the first magnetic layer21. The second non-magnetic layer42is provided between the first magnetic layer21and the third magnetic layer23. The third non-magnetic layer43is provided between the third magnetic layer23and the second magnetic layer22. The fourth non-magnetic layer44is provided between the second magnetic layer22and the fourth magnetic layer24. The fifth non-magnetic layer45is provided between the fourth magnetic layer24and the second magnetic pole32.

The first thickness t1along the first direction D1of the first magnetic layer21is thicker than the third thickness t3along the first direction D1of the third magnetic layer23. The second thickness t2along the first direction D1of the second magnetic layer22is thicker than the fourth thickness t4along the first direction D1of the fourth magnetic layer24. The third thickness t3is, for example, 0.75 times or less of the first thickness t1. The fourth thickness t4is, for example, 0.7 times or less of the second thickness t2.

The magnetic head111also has the same characteristics as the magnetic head110. For example, when the width ratio Rw1is not less than 0.25 and not more than 0.92, the large parameter P1is obtained. In the magnetic head111, the width ratio Rv1is preferably not less than 0.25 and not more than 0.92. The width ratio Rw1may be not less than 0.4 and not more than 0.85. A high efficiency resistance change is obtained, and the alternating magnetic fields is generated more effectively.

Also in the magnetic head111, a large parameter P1is obtained when the length ratio RL1is not less than 0.1 and not more than 0.85. Also in the magnetic head111, the length ratio RL1is preferably not less than 0.1 and not more than 0.85. The length ratio RL1may be not less than 0.2 and not more than 0.72. High efficiency resistance change is obtained, and the alternating magnetic field is generated more effectively.

Efficient MAMR can also be performed in the magnetic head111. According to the embodiments, it is possible to provide a magnetic head capable of improving the recording density.

In the magnetic head111, the first non-magnetic layer41includes at least one selected from the group consisting of, for example, Cu, Au, Cr, Al, V and Ag. For example, the second non-magnetic layer42includes at least one selected from the group consisting of, for example, Ru, Ir, Ta, Rh, Pd, Pt, and W, and the third non-magnetic layer43includes at least one selected from the group consisting of, for example, Cu, Au, Cr, Al, V, and Ag. Alternatively, for example, the second non-magnetic layer42includes at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag, and the third non-magnetic layer43includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth non-magnetic layer44includes, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer45includes, for example, at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

In one example of the magnetic head111, the first non-magnetic layer thickness t41is, for example, not less than 1 nm and not more than 8 nm. The second non-magnetic layer thickness t42is, for example, not less than 1 nm and not more than 8 nm. The third non-magnetic layer thickness t43is, for example, not less than 1 nm and not more than 8 nm. The fourth nonmagnetic layer thickness t44is, for example, not less than 1 nm and not more than 5 nm. The fifth non-magnetic layer thickness t45is, for example, not less than 2 nm and not more than 8 nm.

As shown inFIG.9B, the current ic is supplied to the stacked body20in the magnetic head111. For example, the current ic has an orientation from the first magnetic layer21to the second magnetic layer22. The electron flow je has an orientation from the second magnetic layer22to the first magnetic layer21.

FIGS.10A and10Bare schematic views illustrating the magnetic head according to the first embodiment.

FIG.10Ais a cross-sectional view.FIG.10Bis a plan view seen from arrow AR1inFIG.10A. As shown inFIGS.10A and10B, a magnetic head112according to the embodiment also includes the first magnetic pole31, the second magnetic pole32and the stacked body20. The configuration of the stacked body20in the magnetic head112is different from the configuration of the stacked body20in the magnetic head110. Except for this, the configuration of the magnetic head112may be the same as the configuration of the magnetic head110.

In magnetic head112, the stacked body20includes the first non-magnetic layer41. The first non-magnetic layer41is provided between the first magnetic pole31and the first magnetic layer21. The first non-magnetic layer41includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, for example.

In the magnetic head112, the stacked body20may include a second non-magnetic layer42. The second non-magnetic layer42is provided between the first magnetic layer21and the second magnetic layer22. In one example, the second non-magnetic layer42includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, for example. In another example, the second non-magnetic layer42may include at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, for example.

In the magnetic head112, the stacked body20may include the third non-magnetic layer43. The third non-magnetic layer43is provided between the second magnetic layer22and the second magnetic pole32. In one example, the third non-magnetic layer43includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, for example. In another example, the third non-magnetic layer43may include at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, for example.

The magnetic head112also has the same characteristics as the magnetic head110. For example, when the width ratio Rw1is not less than 0.25 and not more than 0.92, a high parameter P1is obtained. In the magnetic head111, the width ratio Rv1is preferably not less than 0.25 and not more than 0.92. The width ratio Rw1may be not less than 0.4 and not more than 0.85. High efficiency resistance change is obtained, and the alternating magnetic field is generated more effectively.

Also in the magnetic head112, a high parameter P1is obtained when the length ratio RL1is not less than 0.1 and not more than 0.85. Also in the magnetic head111, the length ratio RL1is preferably not less than 0.1 and not more than 0.85. The length ratio RL1may be not less than 0.2 and not more than 0.72. High efficiency resistance change is obtained, and the alternating magnetic field is generated more effectively.

Efficient MAMR can also be performed in the magnetic head112. According to the embodiments, it is possible to provide a magnetic head capable of improving the recording density.

In one example of the magnetic head112, the first non-magnetic layer thickness t41is, for example, not less than 2 nm and not more than 8 nm. The second non-magnetic layer thickness t42is, for example, not less than 1 nm and not more than to 8 nm. The third non-magnetic layer thickness t43is, for example, not less than 1 nm and not more than 8 nm.

As shown inFIG.10B, in one example of the magnetic head112, the current ic has an orientation from the second magnetic layer22to the first magnetic layer21. The electron flow je has an orientation from the first magnetic layer21to the second magnetic layer22. In another example in the magnetic head112, the current ic may have an orientation from the first magnetic layer21to the second magnetic layer22.

In the magnetic head112, for example, the first magnetic layer21can oscillate. The second magnetic layer22can oscillate.

In the magnetic head111and the magnetic head112, for example, when the current ic flows through the stacked body20, the alternating magnetic field Ha1is generated from the stacked body20, and the alternating power Pa1is generated in the stacked body20. For example, the absolute value of the difference between the first frequency of the alternating magnetic field Ha1and the second frequency of the alternating power Pa1is 0.25 times or less of the first frequency.

In the magnetic head111and the magnetic head112, the configuration described with respect to the magnetic head110may be applied. For example, the third length L3(seeFIG.1A) is longer than the second length L2. For example, the third width w3(seeFIG.1B) is wider than the second width w2.

In the magnetic head111and the magnetic head112, the structure described with respect to the magnetic head110a, the magnetic head110band the magnetic head110cmay be applied.

In the following, an example of the magnetic head and the magnetic recording medium80included in the magnetic recording device210according to the embodiment will be described.

FIG.11is a schematic perspective view illustrating the magnetic recording device according to the embodiment.

As shown inFIG.11, the magnetic head according to the embodiment (for example, the magnetic head110) is used together with the magnetic recording medium80. In this example, the magnetic head110includes the recording part60and the reproducing part70. Information is recorded on the magnetic recording medium80by the recording part60of the magnetic head110. The reproducing part70reproduces the information recorded on the magnetic recording medium80.

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 part60.

The reproducing part70includes, 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 element71is possible to output a signal corresponding to the magnetization83of the magnetic recording layer81.

As shown inFIG.11, the magnetic recording medium80moves relative to the magnetic head110in a direction of the medium movement direction85. The magnetic head110controls the information corresponding to the magnetization83of the magnetic recording layer81at an arbitrary position. The magnetic head110reproduces information corresponding to the magnetization83of the magnetic recording layer81at an arbitrary position.

FIG.12is a schematic perspective view illustrating a portion of the magnetic recording device according to the embodiment.

FIG.12illustrates 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.13is a schematic perspective view illustrating a magnetic recording device according to the embodiment.

As shown inFIG.13, 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.

FIGS.14A and14Bare schematic perspective views illustrating a portion of the magnetic recording device according to the embodiment.

FIG.14Aillustrates a partial configuration of the magnetic recording device and is an enlarged perspective view of a head stack assembly160.FIG.14Bis a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA)158that is a portion of the head stack assembly160.

As shown inFIG.14A, 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.14B, 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 embodiment may include the following configurations (e.g., technical proposals).

A magnetic head, comprising:a first magnetic pole, the first magnetic pole including a first face and a second face crossing the first face, the second face including a first face region continuous with the first face;a second magnetic pole, the second magnetic pole including a third face and a fourth face crossing the third face, the fourth face including a second face region, the second face region being continuous with the third face, a direction from the first face region to the second face region being along a first direction, the first face region and the second face region being along a second direction and a third direction, the third direction crossing a plane including the first direction and the second direction, the first face and the third face being along the third direction; anda stacked body provided between the first face region andthe second face region, the stacked body includinga first magnetic layer, anda second magnetic layer provided between the first magnetic layer and the second face region,the second magnetic layer including a second magnetic layer face facing the second face region, anda width ratio of a second width of the second magnetic layer face along the third direction to a first width of the first face region along the third direction being not less than 0.25 and not more than 0.92.
Configuration 2

The magnetic head according to Configuration 1, wherein the width ratio is not less than 0.4 and not more than to 0.85.

The magnetic head according to Configuration 1 or 2, whereinthe second face further includes a third face region,the second face further includes a third face region,the first face region is between the first face and the third face region,the third face region is along the second direction and the third direction,the fourth face further includes a fourth face region and a fifth face region,a direction from the third face region to the fourth face region is along the first direction,the fourth face region is along the second direction and the third direction,a first distance between the first face region and the second face region along the first direction is shorter than a second distance between the third face region and the fourth face region along the first direction,the fifth face region is between the second face region and the fourth face region,a plane including the fifth face region crosses a plane including the third face region and a plane including the fourth face region,the second magnetic pole has a first length along the second direction between a crossing position and the third face, the plane including the fifth face region crossing the plane including the fourth face region at the crossing position, anda length ratio of a second length of the second magnetic layer face along the second direction to the first length is not less than 0.1 and not more than 0.85.
Configuration 4

The magnetic head according to Configuration 3, wherein the length ratio is not less than 0.2 and not more than to 0.72.

The magnetic head according to any one of Configurations 1 to 4, wherein the second direction is inclined with respect to the first direction.

A magnetic head, comprising:a first magnetic pole, the first magnetic pole including a first face and a second face crossing the first face, the second face including a first face region continuous with the first face;a second magnetic pole, the second magnetic pole including a third face and a fourth face crossing the third face, the fourth face including a second face region, the second face region being continuous with the third face, a direction from the first face region to the second face region being along a first direction, the first face region and the second face region being along a second direction and a third direction, the third direction crossing a plane including the first direction and the second direction, the first face and the third face being along the third direction; anda stacked body provided between the first face region and the second face region,the stacked body includinga first magnetic layer, anda second magnetic layer provided between the first magnetic layer and the second face region,the second magnetic layer including a second magnetic layer face facing the second face region,the second face further including a third face region,the first face region being between the first face and the third face region,The third face region being along the second direction and the third direction,the fourth face further including a fourth face region and a fifth face region,a direction from the third surface region to the fourth surface region being along the first direction,the fourth face region being along the second direction and the third direction,a first distance between the first face region and the second face region along the first direction being shorter than a second distance between the third face region and the fourth face region along the first direction,the fifth surface region being between the second face region and the fourth face region,a plane including the fifth face region crossing a plane including the third plane region and a plane including the fourth plane region,the second magnetic pole having a first length along the second direction between a crossing position and the third face, the plane including the fifth face region crossing the plane including the fourth surface region at the crossing position, anda ratio of a second length of the second magnetic layer face along the second direction to the first length being not less than 0.1 and not more than 0.85.
Configuration 7

The magnetic head according to Configuration 6, wherein the length ratio is not less than 0.2 and not more than to 0.72.

The magnetic head according to Configuration 6, wherein the second direction is inclined with respect to the first direction.

The magnetic head according to any one of Configurations 1 to 8, wherein the stacked body further includes a first non-magnetic layer provided between the first magnetic layer and the second magnetic layer.

The magnetic head according to Configuration 9, wherein the stacked body further includes a second non-magnetic layer provided between the first magnetic pole and the first magnetic layer.

The magnetic head according to Configuration 10, wherein the stacked body includes a third non-magnetic layer provided between the second magnetic layer and the second magnetic pole.

The magnetic head according to any one of Configurations 1 to 8, whereinthe stacked body further includesa third magnetic layer provided between the first magnetic pole and the first magnetic layer,a fourth magnetic layer provided between the first magnetic layer and the second magnetic layer,a first non-magnetic layer provided between the first magnetic pole and the third magnetic layer,a second non-magnetic layer provided between the third magnetic layer and the first magnetic layer,a third non-magnetic layer provided between the first magnetic layer and the fourth magnetic layer,a fourth non-magnetic layer provided between the fourth magnetic layer and the second magnetic layer, anda fifth non-magnetic layer provided between the second magnetic layer and the second magnetic pole,a first thickness along the first direction of the first magnetic layer is thicker than a third thickness along the first direction of the third magnetic layer, anda second thickness of the second magnetic layer along the first direction is thicker than the fourth thickness of the fourth magnetic layer along the first direction.
Configuration 13

The magnetic head according to Configuration 12, wherein the first non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W,the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,the fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, andthe third nonmagnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and the fourth non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, or the third non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, and the fourth nonmagnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.
Configuration 14

The magnetic head according to any one of Configurations 1 to 8, whereinthe stacked body further includesa third magnetic layer provided between the first magnetic layer and the second magnetic layer,a fourth magnetic layer provided between the second magnetic layer and the second magnetic pole,a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer,a second non-magnetic layer provided between the first magnetic layer and the third magnetic layer,a third non-magnetic layer provided between the third magnetic layer and the second magnetic layer,a fourth non-magnetic layer provided between the second magnetic layer and the fourth magnetic layer, anda fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole,a first thickness along the first direction of the first magnetic layer is thicker than a third thickness along the first direction of the third magnetic layer, anda second thickness along the first direction of the second magnetic layer is thicker than a fourth thickness along the first direction of the fourth magnetic layer.
Configuration 15

The magnetic head according to Configuration 14, whereinthe first non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,the fourth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,the fifth non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W, andthe second non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, and the third non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, or the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and the third non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W.
Configuration 16

The magnetic head according to any one of Configurations 12 to 15, whereinwhen a current flows through the stacked body, an alternating magnetic field is generated from the stacked body, the alternating power is generated in the stacked body, andan absolute value of a difference between a first frequency of the alternating magnetic field and a second frequency of the alternating power is 0.25 times or less of the first frequency.
Configuration 17

The magnetic head according to Configuration 16, wherein the first thickness is thicker than the second thickness,at least a part of the alternating power is generated in the second magnetic layer, andat least a part of the alternating magnetic field is generated from the first magnetic layer.
Configuration 18

A magnetic recording device, comprising:a magnetic head including a first magnetic pole, a second magnetic pole, and a stacked body provided between the first magnetic pole and the second magnetic pole; andan electric circuit configured to supply a current to the stacked body,the stacked body including,a first magnetic layer, anda second magnetic layer provided between the first magnetic layer and the second magnetic pole,wherein the alternating power is configured to be generated in the stacked body when the current flows through the stacked body.
Configuration 19

The magnetic recording device according to Configuration 18, whereinwhen the current flows through the stacked body, an alternating magnetic field is generated from the stacked body, andan absolute value of a difference between a first frequency of the alternating magnetic field and a second frequency of the alternating power is 0.25 times or less of the first frequency.
Configuration 20

The magnetic recording device according to Configuration 19, wherein the first frequency is not less than 15 GHz and not more than 50 GHz.

According to the embodiment, a magnetic head and a magnetic recording device can be provided in which the recording density is possible to be improved.

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 heads such as magnetic poles, stacked bodies, magnetic layers, non-magnetic layers, wirings, 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 heads, and magnetic recording devices practicable by an appropriate design modification by one skilled in the art based on the magnetic heads, and the magnetic recording devices described above as embodiments of the invention also are within the scope of the invention to the extent that the purport of the invention is included.