Magnetic Head and Magnetic Recording Device

Abstract

A magnetic head and a magnetic recording device capable of increasing the recording density are provided. According to an embodiment, the magnetic head includes a first magnetic pole, a second magnetic pole, and a laminate. The laminate includes a first magnetic layer to a fourth magnetic layer and a first non-magnetic layer to a fifth non-magnetic layer. The second non-magnetic layer is in contact with the second magnetic layer and the first magnetic layer, the third non-magnetic layer is in contact with the third magnetic layer and the second magnetic layer, the fourth non-magnetic layer is in contact with the fourth magnetic layer and the third magnetic layer. The fourth thickness of the fourth magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is 0.5 times or more and 1.6 times or less the first thickness of the first magnetic layer along the first direction, and the second thickness of the second magnetic layer along the first direction is less than the first thickness.

Description

[0001] This application is based on Japanese Patent Application No. 2021-197483 (filing date: December 6, 2021), and claims priority therefrom. This application incorporates the entire content of that application by reference thereto. Technical Field

[0002] Embodiments of the present invention relate to a magnetic head and a magnetic recording device. Background Art

[0003] Information is recorded on a magnetic recording medium such as an HDD (Hard Disk Drive) using a magnetic head. In magnetic heads and magnetic recording devices, it is desirable to increase the recording density. Summary of the Invention

[0004] Embodiments of the present invention provide a magnetic head and a magnetic recording device capable of increasing the recording density.

[0005] [Technical Solution for Solving the Problem]

[0006] According to an embodiment of the present invention, a magnetic head includes: a first magnetic pole; a second magnetic pole; and a laminate disposed between the first magnetic pole and the second magnetic pole. The laminate includes: a first magnetic layer; a second magnetic layer disposed between the second magnetic pole and the first magnetic layer; a third magnetic layer disposed between the second magnetic pole and the second magnetic layer; a fourth magnetic layer disposed between the second magnetic pole and the third magnetic layer; a first non-magnetic layer disposed between the first magnetic layer and the first magnetic pole; a second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer; a third non-magnetic layer disposed between the third magnetic layer and the second magnetic layer; a fourth non-magnetic layer disposed between the fourth magnetic layer and the third magnetic layer; and a fifth non-magnetic layer disposed between the second magnetic pole and the fourth magnetic layer, the second non-magnetic layer being in contact with the second magnetic layer and the first magnetic layer, the third non-magnetic layer being in contact with the third magnetic layer and the second magnetic layer, the fourth non-magnetic layer being in contact with the fourth magnetic layer and the third magnetic layer, a fourth thickness of the fourth magnetic layer along a first direction from the first magnetic pole to the second magnetic pole being 0.5 times or more and 1.6 times or less a first thickness of the first magnetic layer along the first direction, and a second thickness of the second magnetic layer along the first direction being less than the first thickness.

[0007] According to the magnetic head configured as described above, a magnetic head and a magnetic recording device capable of increasing the recording density can be provided. Description of the Drawings

[0008] Figure 1 of (a) and Figure 1(b) is a schematic diagram illustrating the magnetic head of the first embodiment.

[0009] Figure 2 is a schematic cross-sectional view illustrating the magnetic recording device of the first embodiment.

[0010] Figure 3 is a chart illustrating the characteristics of the magnetic head.

[0011] Figure 4 (a) to Figure 4 (d) is a chart illustrating the characteristics of the magnetic head.

[0012] Figure 5 (a) to Figure 5 (c) is a chart illustrating the characteristics of the magnetic head.

[0013] Figure 6 (a) to Figure 6 (c) is a chart illustrating the characteristics of the magnetic head.

[0014] Figure 7 is a chart illustrating the characteristics of the magnetic head.

[0015] Figure 8 is a chart illustrating the characteristics of the magnetic head.

[0016] Figure 9 (a) and Figure 9 (b) are schematic diagrams illustrating the magnetic head of the first embodiment.

[0017] Figure 10 is a chart illustrating the characteristics of the magnetic head.

[0018] Figure 11 (a) to Figure 11 (d) is a chart illustrating the characteristics of the magnetic head.

[0019] Figure 12 (a) to Figure 12 (c) is a chart illustrating the characteristics of the magnetic head.

[0020] Figure 13 (a) to Figure 13 (c) is a chart illustrating the characteristics of the magnetic head.

[0021] Figure 14 (a) and Figure 14 (b) are charts illustrating the characteristics of the magnetic head.

[0022] Figure 15 is a schematic cross-sectional view illustrating the magnetic head of the embodiment.

[0023] Figure 16 is a schematic perspective view illustrating the magnetic recording device of the embodiment.

[0024] Figure 17 is a schematic perspective view of a part of a magnetic recording device according to an exemplary embodiment.

[0025] Figure 18 is a schematic perspective view of a magnetic recording device according to an exemplary embodiment.

[0026] Figure 19 (a) of Figure 19 and (b) of are schematic perspective views of a part of a magnetic recording device according to an exemplary embodiment.

[0027]

Description of Reference Numerals

[0028] 20... laminate, 20D... electric circuit, 21 - 24... first magnetic layer - fourth magnetic layer, 30D... recording circuit, 30F... medium opposing surface, 30c... coil, 30i... insulating part, 31, 32... first magnetic pole, second magnetic pole, 33... shield, 41 - 45... first non - magnetic layer - fifth non - magnetic layer, 60... recording part, 70... reproducing part, 71... magnetic reproducing element, 72a, 72b... first reproducing magnetic shield, second reproducing magnetic shield, 80... magnetic recording medium, 81... magnetic recording layer, 82... medium substrate, 83... magnetization, 85... medium moving direction, θ1... angle, 110... magnetic head, 150... magnetic recording device, 154... suspension, 155... arm, 156... voice coil motor, 157... bearing part, 158... head gimbal assembly, 159... head slider, 159A... air inflow side, 159B... air outflow side, 160... head stack assembly, 161... support frame, 162... coil, 180... recording medium disk, 180M... spindle motor, 181... recording medium, 190... signal processing part, 210... magnetic recording device, AR, AR1... arrow, D1... first direction, Iw... recording current, OS... oscillation intensity, MD1 - MD3... first model - third model, MD11 - MD14, MD31 - MD35... model, OS... oscillation intensity, R21, R23, R31, R41, R42, R43... ratio, T1, T2... first terminal, second terminal, W1, W2... first wiring, second wiring, d1... distance, ic... current, jc... current density, je... electron flow, t1 - t4... first thickness - fourth thickness, t41 - t45... thickness Detailed Embodiments

[0029] Hereinafter, each embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] The accompanying drawings are schematic or conceptual, and the relationships between the thicknesses and widths of the respective parts, the ratios of the sizes between parts, etc. are not necessarily the same as in reality. Even when representing the same part, there are cases where the sizes and ratios are represented differently according to the accompanying drawings.

[0031] In the specification of the present application and in each of the accompanying drawings, for elements that are the same as those previously described with respect to the accompanying drawings that have already appeared, the same reference numerals are assigned, and detailed descriptions are appropriately omitted.

[0032] (First Embodiment)

[0033] Figure 1 of (a) and Figure 1 of (b) are schematic views illustrating the magnetic head of the first embodiment.

[0034] Figure 1 of (a) is a cross-sectional view. Figure 1 of (b) is a top view observed from the arrow AR1 of Figure 1 of (a).

[0035] Figure 2 is a schematic cross-sectional view illustrating the magnetic recording device of the first embodiment.

[0036] As Figure 2 shown, the magnetic recording device 210 of the embodiment includes a magnetic head 110 and an electric circuit 20D. The magnetic recording device 210 may also include a magnetic recording medium 80. In the magnetic recording device 210, at least a recording operation is performed. In the recording operation, the magnetic head 110 is used to record information on the magnetic recording medium 80.

[0037] The magnetic head 110 includes a recording section 60. As will be described later, the magnetic head 110 may also include a reproducing section. The recording section 60 includes a first magnetic pole 31, a second magnetic pole 32, and a laminate 20. The laminate 20 is disposed between the first magnetic pole 31 and the second magnetic pole 32.

[0038] For example, the first magnetic pole 31 and the second magnetic pole 32 form a magnetic circuit. The first magnetic pole 31 is, for example, a main magnetic pole. The second magnetic pole 32 is, for example, a trailing shield. Alternatively, the first magnetic pole 31 may be a trailing shield and the second magnetic pole 32 may be a main magnetic pole.

[0039] The direction from the magnetic recording medium 80 to the magnetic head 110 is set as the Z-axis direction. One direction perpendicular to the Z-axis direction is set as the X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is set as the Y-axis direction. The Z-axis direction corresponds to, for example, the height direction. The X-axis direction corresponds to, for example, the tracking (along the track) direction. The Y-axis direction corresponds to, for example, the cross-track (crossing the track) direction. Along the tracking direction, the magnetic recording medium 80 moves relative to the magnetic head 110. A magnetic field (recording magnetic field) generated from the magnetic head 110 is applied to a desired position of the magnetic recording medium 80. The magnetization of the desired position of the magnetic recording medium 80 is controlled in a direction corresponding to the recording magnetic field. Thereby, information is recorded on the magnetic recording medium 80.

[0040] The direction from the first magnetic pole 31 to the second magnetic pole 32 is set as the first direction D1. The first direction D1 substantially follows the X-axis direction. In the embodiment, the first direction D1 may be inclined at a small angle with respect to the X-axis direction.

[0041] As Figure 2 shown, a coil 30c is provided. In this example, a part of the coil 30c is between the first magnetic pole 31 and the second magnetic pole 32. In this example, a shield 33 is provided. In the X-axis direction, the first magnetic pole 31 is between the shield 33 and the second magnetic pole 32. Another part of the coil 30c is between the shield 33 and the first magnetic pole 31. An insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 may also include side shields (not shown).

[0042] As Figure 2 shown, a recording current Iw is supplied from the recording circuit 30D to the coil 30c. A recording magnetic field corresponding to the recording current Iw is applied from the first magnetic pole 31 to the magnetic recording medium 80.

[0043] As Figure 2 shown, the first magnetic pole 31 includes a medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F faces the magnetic recording medium 80, for example. The medium facing surface 30F is along the X-Y plane, for example.

[0044] As Figure 2 shown, the electric circuit 20D is electrically connected to the laminate 20. In this example, the laminate 20 is electrically connected to the first magnetic pole 31 and the second magnetic pole 32. In the magnetic head 110, a first terminal T1 and a second terminal T2 are provided. The first terminal T1 is electrically connected to the laminate 20 via the first wiring W1 and the first magnetic pole 31. The second terminal T2 is electrically connected to the laminate 20 via the second wiring W2 and the second magnetic pole 32. A current (for example, a direct current) is supplied from the electric circuit 20D to the laminate 20, for example.

[0045] As shown in Figure 1 FIG. (a) of Figure 1 and FIG. (b) of Figure 1 FIG. (a) of Figure 1 FIG. (b) of

[0046] The first magnetic layer 21 is disposed between the first magnetic pole 31 and the second magnetic pole 32. The second magnetic layer 22 is disposed between the second magnetic pole 32 and the first magnetic layer 21. The third magnetic layer 23 is disposed between the second magnetic pole 32 and the second magnetic layer 22. The fourth magnetic layer 24 is disposed between the second magnetic pole 32 and the third magnetic layer 23. The first non-magnetic layer 41 is disposed between the first magnetic layer 21 and the first magnetic pole 31. The second non-magnetic layer 42 is disposed between the second magnetic layer 22 and the first magnetic layer 21. The third non-magnetic layer 43 is disposed between the third magnetic layer 23 and the second magnetic layer 22. The fourth non-magnetic layer 44 is disposed between the fourth magnetic layer 24 and the third magnetic layer 23. The fifth non-magnetic layer 45 is disposed between the second magnetic pole 32 and the fourth magnetic layer 24.

[0047] For example, the first non-magnetic layer 41 may be in contact with the first magnetic layer 21 and the first magnetic pole 31. The second non-magnetic layer 42 may be in contact with the second magnetic layer 22 and the first magnetic layer 21. The third non-magnetic layer 43 may be in contact with the third magnetic layer 23 and the second magnetic layer 22. The fourth non-magnetic layer 44 may be in contact with the fourth magnetic layer 24 and the third magnetic layer 23. The fifth non-magnetic layer 45 may be in contact with the second magnetic pole 32 and the fourth magnetic layer 24.

[0048] The first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 contain a first element, which includes at least one selected from the group consisting of Fe, Co, and Ni. These magnetic layers may contain, for example, an FeCo alloy or the like.

[0049] The first non-magnetic layer 41 contains, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag. The fifth non-magnetic layer 45 contains, for example, at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W. Thus, in the laminate 20, the first non-magnetic layer 41 and the fifth non-magnetic layer 45 are asymmetric.

[0050] The second non-magnetic layer 42 contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag, and the third non-magnetic layer 43 contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth non-magnetic layer 44 contains, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0051] As Figure 1 shown in (b) of FIG., a current ic is supplied to such a laminate 20. The current ic is supplied, for example, from the above-described electric circuit 20D. As Figure 1 shown in (b) of FIG., the current ic has a direction from the first magnetic layer 21 toward the second magnetic layer 22. As Figure 1 shown in (b) of FIG., the electron flow je accompanying the current ic has a direction from the second magnetic layer 22 toward the first magnetic layer 21. The direction of the current ic is a direction from the first magnetic pole 31 toward the second magnetic pole 32.

[0052] For example, when a current ic above a threshold value flows through the laminate 20, the magnetization of the magnetic layers included in the laminate 20 oscillates. The laminate 20 functions, 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 laminate 20. The alternating magnetic field generated in the laminate 20 is applied to the magnetic recording medium 80 to assist writing to the magnetic recording medium 80. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented.

[0053] In the magnetic head 110, the first magnetic layer 21 and the fourth magnetic layer 24 function, for example, as oscillation layers. For example, the magnetization 21M of the first magnetic layer 21 and the magnetization 24M of the fourth magnetic layer 24 rotate. The second magnetic layer 22 and the third magnetic layer 23 function, for example, as spin injection layers. The first magnetic pole 31 includes a portion facing the laminate 20. In this facing portion, the first magnetic pole 31 has a magnetization 31M. For example, the direction of the magnetization 22M of the second magnetic layer 22 is reversed with respect to the magnetization 31M. For example, the magnetization 23M of the third magnetic layer 23 has the direction of the magnetization 31M. The magnetization 22M is reversed with respect to the magnetization 23M. For example, spins are injected from the third magnetic layer 23 into the fourth magnetic layer 24. Spins are injected from the second magnetic layer 22 into the first magnetic layer 21. For example, corresponding to the reversal of the recording current Iw, the direction of the magnetization 31M is reversed, and the magnetizations 22M and 23M are respectively reversed.

[0054] As Figure 1As shown in (b) of FIG. , the thickness of the first magnetic layer 21 along the first direction D1 (the direction from the first magnetic pole 31 to the second magnetic pole 32) is set as the first thickness t1. The thickness of the second magnetic layer 22 along the first direction D1 is set as the second thickness t2. The thickness of the third magnetic layer 23 along the first direction D1 is set as the third thickness t3. The thickness of the fourth magnetic layer 24 along the first direction D1 is set as the fourth thickness t4. In the embodiment, the difference between the first thickness t1 and the fourth thickness t4 is small. For example, the fourth thickness t4 is 0.5 times or more and 1.6 times or less of the first thickness t1. The second thickness t2 is smaller than the first thickness t1, whereby, as will be described later, oscillation is easily obtained.

[0055] The thickness of the first non-magnetic layer 41 along the first direction D1 is set as the thickness t41. The thickness of the second non-magnetic layer 42 along the first direction D1 is set as the thickness t42. The thickness of the third non-magnetic layer 43 along the first direction D1 is set as the thickness t43. The thickness of the fourth non-magnetic layer 44 along the first direction D1 is set as the thickness t44. The thickness of the fifth non-magnetic layer 45 along the first direction D1 is set as the thickness t45. These thicknesses are, for example, 0.5 nm or more and 6 nm or less. By these thicknesses being 0.5 nm or more, for example, magnetic coupling is easily reduced. For example, high oscillation intensity is easily obtained. By these thicknesses being 6 nm or less, for example, the thickness of the laminate 20 can be suppressed. For example, the distance (recording gap) between the first magnetic pole 31 and the second magnetic pole 32 can be reduced. Thereby, high recording density is easily obtained.

[0056] Hereinafter, an example of the simulation result of the behavior of oscillation in the laminate 20 will be described. In the first model of the simulation, there is provided Figure 1 the configuration shown in (b) of FIG. . That is, the first magnetic pole 31, the second magnetic pole 32, the first magnetic layer to the fourth magnetic layer 21 to 24, and the first non-magnetic layer to the fifth non-magnetic layer 41 to 45 are provided. As the physical property values of the first magnetic layer 21 and the fourth magnetic layer 24, the physical property values of a Fe 70 Co 30 alloy are used. As the physical property values of the second magnetic layer 22 and the third magnetic layer 23, the physical property values of a FeNi alloy are used. In this example, the FeNi alloy is Fe 78 Ni 22 . The first thickness t1 is 6.5 nm. The second thickness t2 is 3 nm. The third thickness t3 is 3 nm. The fourth thickness t4 is 6.5 nm. The thicknesses t41 to t45 are 2 nm. In the first model, as the physical property values of the first non-magnetic layer 41, the second non-magnetic layer 42, and the fourth non-magnetic layer 44, the physical property values of Cu are used. As the physical property values of the third non-magnetic layer 43 and the fifth non-magnetic layer 45, the physical property values of Ta are used.

[0057] In the second model of the simulation, the second magnetic layer 22 and the second non-magnetic layer 42 are not provided, and the third non-magnetic layer 43 is in contact with the first magnetic layer 21. The third magnetic layer 23 exchanges with the fourth magnetic layer 24. The other configurations in the second model are the same as those in the first model. In these models, the simulation Figure 1 The magnetization oscillation characteristics when the current ic illustrated in (b) is supplied.

[0058] Figure 3 It is a chart illustrating the characteristics of the magnetic head.

[0059] Figure 3 The horizontal axis is the current density jc. The vertical axis is the oscillation strength OS. The oscillation strength OS is the sum of the product of the amplitude of the vibration of the magnetization 21M of the first magnetic layer 21 and the first thickness t1 and the product of the amplitude of the vibration of the magnetization 24M of the fourth magnetic layer 24 and the fourth thickness t4. In the case where the oscillation strength OS is high, for example, the recording density based on MAMR is likely to be increased.

[0060] As Figure 3 shown, in the region where the current density jc is low, the oscillation strength OS of the first model MD1 is higher than the oscillation strength OS of the second model MD2. Thus, by including the first magnetic layer to the fourth magnetic layer 21 to 24, a high oscillation strength OS can be obtained. It is considered that this is because: by adding the second magnetic layer 22 and the second non-magnetic layer 42, the spin is effectively injected into the oscillation layer (i.e., the first magnetic layer 21 or the fourth magnetic layer 24).

[0061] According to the embodiment, for example, a high oscillation strength OS can be obtained. A more stable oscillation can be obtained. According to the embodiment, stable MAMR can be implemented. A magnetic head capable of increasing the recording density can be provided.

[0062] Figure 4 (a) to Figure 4 (d) are charts illustrating the characteristics of the magnetic head.

[0063] Figure 4 The horizontal axis of (a) is the first thickness t1. In Figure 4 (a), the second thickness t2 is 1 nm, the third thickness t3 is 3 nm, and the fourth thickness t4 is 10 nm. Figure 4 The horizontal axis of (b) is the second thickness t2. In Figure 4 (b), the first thickness t1 is 10 nm, the third thickness t3 is 1 nm, and the fourth thickness t4 is 10 nm. Figure 4 The horizontal axis of (c) is the third thickness t3. In Figure 4 (c), the first thickness t1 is 10 nm, the second thickness t2 is 1 nm, and the fourth thickness t4 is 10 nm. Figure 4In (d), the horizontal axis is the fourth thickness t4. In Figure 4 (d), the first thickness t1 is 10 nm, the second thickness t2 is 1 nm, and the third thickness t3 is 1 nm. In these figures, the current density jc supplied to the laminate 20 is 1.2×10 8 A / cm 2 . The vertical axis of these figures is the oscillation strength OS.

[0064] As Figure 4 shown in (a), the first thickness t1 is preferably 5 nm or more and 15 nm or less. Thereby, a high oscillation strength OS can be obtained.

[0065] As Figure 4 shown in (b), when the second thickness t2 is 5 nm or less, a high oscillation strength OS can be obtained. For example, the second thickness t2 is preferably 1 nm or more and 5 nm or less. By making the second thickness t2 thin, for example, the magnetization 22M is easily reversed with respect to the magnetization 31M. Thereby, the threshold value of the current required for oscillation becomes small. For example, the second thickness t2 may also be 3 nm or less. For example, the second thickness t2 may also be 2 nm or less.

[0066] As Figure 4 shown in (c), it does not substantially change in the range where the third thickness t3 is 1 nm or more and 9 nm or less. The third thickness t3 is preferably 9 nm or less. Thereby, the absolute value of the magnetization along the direction of the magnetization 31M in the laminate 20 can be reduced. It is easy to obtain a high recording density. For example, the third thickness t3 may also be 5 nm or less. For example, the third thickness t3 may also be 3 nm or less. The third thickness t3 may also be 1 nm.

[0067] As Figure 4 shown in (d), when the fourth thickness t4 is 5 nm or more and 15 nm or less, a high oscillation strength OS can be obtained. The fourth thickness t4 is preferably 5 nm or more and 15 nm or less, for example. The fourth thickness t4 may also be 8 nm or more and 12 nm or less.

[0068] Figure 5 (a) to Figure 5 (c) are charts illustrating the characteristics of the magnetic head.

[0069] Figure 5 In (a), the horizontal axis is the ratio R21. The ratio R21 is the ratio of the second thickness t2 to the first thickness t1. Figure 5 In (b), the horizontal axis is the ratio R31. The ratio R31 is the ratio of the third thickness t3 to the first thickness t1. Figure 5 In (c), the horizontal axis is the ratio R41. The ratio R41 is the ratio of the fourth thickness t4 to the first thickness t1. In Figure 5In (a), the ratio R31 is 0.13 and the ratio R41 is 1.25. In Figure 5 In (b), the ratio R21 is 0.1 and the ratio R41 is 1. In Figure 5 In (c), the ratio R21 is 0.1 and the ratio R31 is 0.1.

[0070] As Figure 5 shown in (a), when the ratio R21 is low, a high oscillation intensity OS can be obtained. For example, the second thickness t2 is preferably, for example, less than the first thickness t1. For example, a high oscillation intensity OS can be obtained when the ratio R21 is 0.6 or less. The second thickness t2 is preferably, for example, 0.6 times or less of the first thickness t1. The second thickness t2 can also be, for example, 0.4 times or less of the first thickness t1. The second thickness t2 can also be, for example, 0.38 times or less of the first thickness t1. The magnetization 22M is easily reversed with respect to the magnetization 31M. The threshold value of the current required for oscillation becomes smaller.

[0071] As Figure 5 shown in (b), a high oscillation intensity OS can be obtained in the range where the ratio R31 is 0.9 or less. For example, the third thickness t3 is preferably 0.9 times or less of the first thickness t1. For example, the third thickness t3 can also be, for example, 0.5 times or less of the first thickness t1.

[0072] As Figure 5 shown in (c), when the ratio R41 is 0.5 or more and 1.6 or less, a high oscillation intensity OS can be obtained. For example, the fourth thickness t4 is preferably 0.5 times or more and 1.6 times or less of the first thickness t1. For example, the fourth thickness t4 can also be 1.5 times or less of the first thickness t1. A high oscillation intensity OS can be obtained.

[0073] Figure 6 (a) to Figure 6 (c) are charts illustrating the characteristics of the magnetic head.

[0074] Figure 6 The horizontal axis of (a) is the ratio R23. The ratio R23 is the ratio of the second thickness t2 to the third thickness t3. Figure 6 The horizontal axis of (b) is the ratio R24. The ratio R43 is the ratio of the second thickness t2 to the fourth thickness t4. Figure 5 The horizontal axis of (c) is the ratio R34. The ratio R24 is the ratio of the second thickness t2 to the fourth thickness t4. In Figure 6 In (a), the ratio R31 is 0.3 and the ratio R41 is 1. In Figure 6 In (b), the ratio R31 is 0.1 and the ratio R41 is 0.8. In Figure 6 In (c), the ratio R21 is 0.1 and the ratio R41 is 1.

[0075] AsFigure 6 As shown in (a) of FIG. , when R23 is 1 or less, a high oscillation intensity OS can be obtained. The second thickness t2 is preferably, for example, equal to or less than the third thickness t3. The second thickness t2 can also be, for example, 0.5 times or less of the third thickness t3. The second thickness t2 can also be, for example, 0.3 times or less of the third thickness t3. The magnetization 22M is easily reversed with respect to the magnetization 31M. The threshold value of the current required for oscillation becomes smaller.

[0076] As Figure 6 shown in (b) of FIG. , when R24 is 0.6 or less, a high oscillation intensity OS can be obtained. For example, the second thickness t2 is preferably 0.6 times or less of the fourth thickness t4. For example, the second thickness t2 can also be 0.4 times or less of the fourth thickness t4. For example, the second thickness t2 can also be 0.38 times or less of the fourth thickness t4. A higher oscillation intensity OS can be obtained.

[0077] As Figure 6 shown in (c) of FIG. , when R34 is 0.9 or less, a high oscillation intensity OS can be obtained. For example, the third thickness t3 is preferably 0.9 times or less of the fourth thickness t4. For example, the third thickness t3 can also be 0.5 times or less of the fourth thickness t4. The absolute value of the magnetization along the direction of the magnetization 31M in the laminate 20 can be reduced. It is easy to obtain a high recording density.

[0078] As described above, the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 contain a first element, and the first element includes at least one selected from the group consisting of Fe, Co, and Ni. In an embodiment, for example, the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 substantially do not contain a second element, and the second element includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. Alternatively, the concentration of the second element in the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 is less than 10 atm%. For example, the first magnetic layer to the fourth magnetic layer 21 to 24 have, for example, positive polarization. In such a magnetic layer, stable oscillation is easily obtained.

[0079] Figure 7 is a graph illustrating the characteristics of the magnetic head.

[0080] In Figure 7In [the figure], the characteristics of models MD11, MD12, MD13, and MD14 are shown. In model MD11, the first non-magnetic layer 41 is a Cu layer, and the fifth non-magnetic layer 45 is a Ta layer. In model MD12, the first non-magnetic layer 41 is a Ta layer, and the fifth non-magnetic layer 45 is a Ta layer. In model MD13, the first non-magnetic layer 41 is a Cu layer, and the fifth non-magnetic layer 45 is a Cu layer. In model MD14, the first non-magnetic layer 41 is a Ta layer, and the fifth non-magnetic layer 45 is a Cu layer. In these models, the second non-magnetic layer 42 is a Cu layer, the third non-magnetic layer 43 is a Ta layer, and the fourth non-magnetic layer 44 is a Cu layer. In Figure 7 In [the figure], the horizontal axis is the current density jc. The vertical axis is the oscillation strength OS.

[0081] As Figure 7 shown, in model MD11, a higher oscillation strength OS than others can be obtained. In an embodiment, the first non-magnetic layer 41 is preferably a Cu layer. In this case, the fifth non-magnetic layer 45 can be a Ta layer or a Cu layer.

[0082] Figure 8 is a chart illustrating the characteristics of the magnetic head.

[0083] Figure 8 Illustrates the characteristics of the laminate 20 including two oscillation layers. Figure 8 The horizontal axis of [the figure] is the distance d1 between the two oscillation layers. The vertical axis is the intensity Ha1 of the alternating magnetic field generated from the laminate 20. In this example, the intensity Ha1 is the intensity at a position 10 nm away from the laminate 20 in the Z-axis direction. As Figure 8 shown, if the distance d1 is too short, the intensity Ha1 is low. The distance d1 is preferably 5 nm or more. When the distance d1 is 8 nm or more, the intensity Ha1 has a tendency to saturate. When the distance d1 becomes 16 nm or more, the intensity Ha1 has a tendency to slightly decrease.

[0084] As Figure 1 shown in (b) of [the figure], the distance d1 corresponds to the distance between the fourth magnetic layer 24 and the first magnetic layer 21. In an embodiment, the distance d1 is preferably 5 nm or more and 16 nm or less. Thereby, a high-intensity Ha1 of the alternating magnetic field is obtained. The distance d1 is more preferably 8 nm or more and 16 nm or less.

[0085] In the magnetic head of the embodiment, between the first magnetic layer 21 and the fourth magnetic layer 24, two magnetic layers (the second magnetic layer 22 and the third magnetic layer 23) are provided. In such a configuration, the distance d1 between the first magnetic layer 21 and the fourth magnetic layer 24 is moderately enlarged. A high-intensity Ha1 alternating magnetic field with a high oscillation strength OS is applied to the magnetic recording medium 80. High-efficiency MAMR can be implemented.

[0086] (The second embodiment)

[0087] Figure 9 (a) and Figure 9 (b) of FIG. are schematic views illustrating the magnetic head according to the first embodiment.

[0088] Figure 9 (a) of FIG. is a cross-sectional view. Figure 9 (b) of FIG. is a Figure 9 top view observed from the arrow AR1 of (a) of FIG.

[0089] The magnetic recording device 210 according to the embodiment includes the magnetic head 120 and the electric circuit 20D according to the second embodiment. Hereinafter, parts different from the magnetic head 110 will be described with respect to the magnetic head 120.

[0090] As Figure 9 (a) and Figure 9 (b) of FIG. show, the laminate 20 includes a first magnetic layer 21, a second magnetic layer 22, a third magnetic layer 23, a fourth magnetic layer 24, a first non-magnetic layer 41, a second non-magnetic layer 42, a third non-magnetic layer 43, a fourth non-magnetic layer 44, and a fifth non-magnetic layer 45.

[0091] The first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 contain a first element, and the first element includes at least one selected from the group consisting of Fe, Co, and Ni. These magnetic layers may contain, for example, an FeCo alloy or the like.

[0092] The first non-magnetic layer 41 contains, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag. The fifth non-magnetic layer 45 contains, for example, at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0093] The second non-magnetic layer 42 contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag. The third non-magnetic layer 43 contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth non-magnetic layer 44 contains, for example, at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0094] Also in the magnetic head 120, when a current ic above the threshold flows through the laminate 20, the magnetization of the magnetic layers included in the laminate 20 oscillates. For example, MAMR can be implemented.

[0095] In the magnetic head 110, the first magnetic layer 21 and the third magnetic layer 23 function as, for example, oscillation layers. For example, the magnetization of the first magnetic layer 21 and the magnetization of the third magnetic layer 23 rotate. The second magnetic layer 22 and the fourth magnetic layer 24 function as, for example, spin injection layers. For example, spin is injected from the second magnetic layer 22 into the first magnetic layer 21, and spin is injected from the fourth magnetic layer 24 into the third magnetic layer 23.

[0096] In the magnetic head 120, the difference between the third thickness t3 and the first thickness t1 is small. For example, the third thickness t3 is 0.5 times or more and 1.5 times or less the first thickness t1. Thus, as will be described later, oscillation is easily obtained. The thicknesses of the non-magnetic layers (thicknesses t41, t42, t43, t44, and t45) are, for example, 0.5 nm or more and 6 nm or less.

[0097] Hereinafter, an example of the simulation result of the behavior of oscillation in the laminate 20 will be described. In the third model of the simulation, the configuration shown in Figure 9 (b) is provided. That is, a first magnetic pole 31, a second magnetic pole 32, first to fourth magnetic layers 21 to 24, and first to fifth non-magnetic layers 41 to 45 are provided. As the physical property values of the first magnetic layer 21 and the third magnetic layer 23, the physical property values of an Fe 70 Co 30 alloy are used. As the physical property values of the second magnetic layer 22 and the fourth magnetic layer 24, the physical property values of an FeNi alloy are used. In this example, the FeNi alloy is Fe 78 Ni 22 . The first thickness t1 is 6.5 nm. The second thickness t2 is 3 nm. The third thickness t3 is 6.5 nm. The fourth thickness t4 is 3 nm. The thicknesses t41 to t45 are 2 nm. In the third model, as the physical property values of the first non-magnetic layer 41, the second non-magnetic layer 42, and the fourth non-magnetic layer 44, the physical property values of Cu are used. As the physical property values of the third non-magnetic layer 43 and the fifth non-magnetic layer 45, the physical property values of Ta are used.

[0098] Figure 10 is a graph illustrating the characteristics of the magnetic head.

[0099] Figure 10 The horizontal axis of is the current density jc. The vertical axis is the oscillation intensity OS. In Figure 10 , the characteristics of the third model MD3 and the second model MD2 are shown. The result of the second model MD2 is the same as the result of the second model MD2 described with respect to Figure 3 .

[0100] As Figure 10As shown, in the region where the current density jc is low, the oscillation strength OS of the third model MD3 is higher than that of the second model MD2. Thus, by including the first magnetic layer to the fourth magnetic layers 21 to 24, a high oscillation strength OS can be obtained. This is presumably because the spin injected into the oscillation layer (i.e., the first magnetic layer 21 or the third magnetic layer 23) increases by adding the second magnetic layer 22.

[0101] According to the magnetic head 120, for example, a high oscillation strength OS can be obtained. More stable oscillation can be obtained. According to the embodiment, stable MAMR can be implemented. A magnetic head capable of increasing the recording density can be provided.

[0102] Figure 11 of (a) to Figure 11 (d) are diagrams illustrating the characteristics of the magnetic head.

[0103] Figure 11 In (a), the horizontal axis is the first thickness t1. In Figure 11 (a), the second thickness t2 is 2 nm, the third thickness t3 is 10 nm, and the fourth thickness t4 is 3 nm. Figure 11 In (b), the horizontal axis is the second thickness t2. In Figure 11 (b), the first thickness t1 is 8 nm, the third thickness t3 is 10 nm, and the fourth thickness t4 is 3 nm. Figure 11 In (c), the horizontal axis is the third thickness t3. In Figure 11 (c), the first thickness t1 is 10 nm, the second thickness t2 is 2 nm, and the fourth thickness t4 is 3 nm. Figure 11 In (d), the horizontal axis is the fourth thickness t4. In Figure 11 (d), the first thickness t1 is 8 nm, the second thickness t2 is 3 nm, and the third thickness t3 is 10 nm. In these figures, the current density jc supplied to the laminate 20 is 1.2×10 8 A / cm 2 . The vertical axis of these figures is the oscillation strength OS.

[0104] As Figure 11 shown in (a), the first thickness t1 is preferably 5 nm or more and 14 nm or less. Thereby, a high oscillation strength OS can be obtained.

[0105] As Figure 11 shown in (b), the second thickness t2 is preferably 5 nm or less. Thereby, a high oscillation strength OS can be obtained. The second thickness t2 can be, for example, 1 nm or more and 5 nm or less.

[0106] As Figure 11As shown in (c), the third thickness t3 is preferably 5 nm or more and 14 nm or less. Thereby, a high oscillation strength OS can be obtained.

[0107] As Figure 11 shown in (d), the fourth thickness t4 is preferably 5 nm or less. Thereby, a high oscillation strength OS can be obtained. The fourth thickness t4 is, for example, 1 nm or more and 5 nm or less.

[0108] Figure 12 of (a) to Figure 12 (c) is a graph illustrating the characteristics of the magnetic head.

[0109] Figure 12 In the horizontal axis of (a), the ratio R21. The ratio R21 is the ratio of the second thickness t2 to the first thickness t1. Figure 12 In the horizontal axis of (b), the ratio R31. The ratio R31 is the ratio of the third thickness t3 to the first thickness t1. Figure 12 In the horizontal axis of (c), the ratio R41. The ratio R41 is the ratio of the fourth thickness t4 to the first thickness t1. In Figure 12 In (a), the ratio R31 is 1 and the ratio R41 is 0.2. In Figure 12 In (b), the ratio R21 is 0.375 and the ratio R41 is 0.25. In Figure 12 In (c), the ratio R21 is 0.3 and the ratio R31 is 0.8.

[0110] As Figure 12 shown in (a), the ratio R21 is preferably low. Thereby, a high oscillation strength OS can be obtained. For example, the second thickness t2 is preferably less than the first thickness t1. For example, the second thickness t2 is preferably 0.5 times or less of the first thickness t1. For example, the second thickness t2 may also be 0.3 times or less of the first thickness t1. A high oscillation strength OS can be obtained.

[0111] As Figure 12 shown in (b), the ratio R31 is preferably close to 1.25. Thereby, a high oscillation strength OS can be obtained. For example, the third thickness t3 is preferably 0.5 times or more and 1.5 times or less of the first thickness t1. For example, the third thickness t3 may also be 0.75 times or more and 1.5 times or less of the first thickness t1. A high oscillation strength OS can be obtained.

[0112] As Figure 12 shown in (c), the ratio R41 is preferably low. Thereby, a high oscillation strength OS can be obtained. For example, the fourth thickness t4 is preferably less than the first thickness t1. For example, the fourth thickness t4 is preferably 0.5 times or less of the first thickness t1. For example, the fourth thickness t4 may also be 0.3 times or less of the first thickness t1. A high oscillation strength OS can be obtained.

[0113] Figure 13 (a) to Figure 13 (c) are diagrams illustrating the characteristics of the magnetic head.

[0114] Figure 13 In (a), the horizontal axis is the ratio R23. The ratio R23 is the ratio of the second thickness t2 to the third thickness t3. Figure 13 In (b), the horizontal axis is the ratio R43. The ratio R43 is the ratio of the fourth thickness t4 to the third thickness t3. Figure 13 In (c), the horizontal axis is the ratio R24. The ratio R24 is the ratio of the second thickness t2 to the fourth thickness t4. In Figure 13 (a), the ratio R31 is 1.25 and the ratio R41 is 0.375. In Figure 13 (b), the ratio R21 is 0.375 and the ratio R31 is 1.25. In Figure 13 (c), the ratio R31 is 1.25. At some points, the ratio R21 is 0.375 and the ratio R41 varies. At other points, the ratio R41 is 0.375 and the ratio R21 varies.

[0115] As Figure 13 (a) shows, the ratio R23 is preferably low. Thus, a high oscillation strength OS can be obtained. For example, the second thickness t2 is preferably 0.5 times or less of the third thickness t2. For example, the second thickness t2 can also be 0.3 times or less of the third thickness t3. A high oscillation strength OS can be obtained.

[0116] As Figure 13 (b) shows, the ratio R43 is preferably low. Thus, a high oscillation strength OS can be obtained. For example, the fourth thickness t4 is preferably 0.5 times or less of the third thickness t3. For example, the fourth thickness t4 can also be 0.3 times or less of the third thickness t3. A high oscillation strength OS can be obtained.

[0117] As Figure 13 (c) shows, the ratio R24 is preferably close to 1. Thus, a high oscillation strength OS can be obtained. For example, the second thickness t2 is preferably 0.43 times or more and 2.33 times or less of the fourth thickness t4. For example, the second thickness t2 can also be 0.6 times or more and 1.67 times or less of the fourth thickness t4. A high oscillation strength OS can be obtained.

[0118] As described above, the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 contain a first element, which includes at least one selected from the group consisting of Fe, Co, and Ni. In an embodiment, for example, the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 substantially do not contain a second element, which includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. Alternatively, the concentration of the second element in the first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 is less than 10 atm%. For example, the first magnetic layer to the fourth magnetic layer 21 to 24 have, for example, positive polarization. In such a magnetic layer, stable oscillation is easily obtained.

[0119] Figure 14 (a) of and Figure 14 (b) of are diagrams illustrating the characteristics of the magnetic head.

[0120] In Figure 14 (a) of and Figure 14 (b) of, the characteristics of the models MD31, MD32, MD33, MD34, and MD35 are shown.

[0121] In the model MD31, the first non-magnetic layer 41 is a Cu layer, the second non-magnetic layer 42 is a Cu layer, the third non-magnetic layer 43 is a Ta layer, the fourth non-magnetic layer 44 is a Cu layer, and the fifth non-magnetic layer 45 is a Ta layer.

[0122] In the model MD32, the first non-magnetic layer 41 is a Cr layer, the second non-magnetic layer 42 is a Cu layer, the third non-magnetic layer 43 is a Ta layer, the fourth non-magnetic layer 44 is a Cu layer, and the fifth non-magnetic layer 45 is a Ta layer.

[0123] In the model MD33, the first non-magnetic layer 41 is a Ta layer, the second non-magnetic layer 42 is a Cu layer, the third non-magnetic layer 43 is a Ta layer, the fourth non-magnetic layer 44 is a Cu layer, and the fifth non-magnetic layer 45 is a Ta layer.

[0124] In the model MD34, the first non-magnetic layer 41 is a Cu layer, the second non-magnetic layer 42 is a Cr layer, the third non-magnetic layer 43 is a Ta layer, the fourth non-magnetic layer 44 is a Cu layer, and the fifth non-magnetic layer 45 is a Ta layer.

[0125] In the model MD35, the first non-magnetic layer 41 is a Cu layer, the second non-magnetic layer 42 is a Cu layer, the third non-magnetic layer 43 is a Ta layer, the fourth non-magnetic layer 44 is a Cr layer, and the fifth non-magnetic layer 45 is a Ta layer.

[0126] In these figures, the horizontal axis is the current density jc. The vertical axis is the oscillation strength OS.

[0127] As shown in Figure 14 (a) of FIG. 1, in the model MD31, the oscillation intensity OS is higher than that of the models MD32 and MD33. In an embodiment, the first non-magnetic layer 41 is preferably a Cu layer.

[0128] As shown in Figure 14 (a) of FIG. 2, at a practical lower current density jc, the characteristics of the models MD34 and MD35 are substantially the same as those of the model MD1. In an embodiment, the second non-magnetic layer 42 can be a Cr layer or a Cu layer. The fourth non-magnetic layer 44 can be a Cr layer or a Cu layer.

[0129] In an embodiment, the first magnetic pole 31 may also include a plurality of magnetic regions arranged along the X-axis direction. The second magnetic pole 32 may also include a plurality of magnetic regions arranged along the X-axis direction. The boundary between the plurality of magnetic regions may be clear or unclear. For example, the plurality of magnetic regions are continuous.

[0130] Hereinafter, examples of the magnetic head and the magnetic recording medium 80 included in the magnetic recording apparatus 210 of the embodiment will be described. In the following description, the magnetic head 110 may also be the magnetic head 120.

[0131] Figure 15 FIG. 3 is a schematic cross-sectional view illustrating a magnetic head according to an embodiment.

[0132] As shown in Figure 15 FIG. 3, in the magnetic head (e.g., the magnetic head 110) of the embodiment, the first direction D1 from the first magnetic pole 31 to the second magnetic pole 32 may be inclined with respect to the X-axis direction. The first direction D1 corresponds to the stacking direction of the laminate 20. The X-axis direction is along the medium facing surface 30F. Let the absolute value of the angle between the first direction D1 and the medium facing surface 30F be the angle θ1. The angle θ1 is, for example, 15 degrees or more and 30 degrees or less. The angle θ1 may also be 0 degrees.

[0133] When the first direction D1 is inclined with respect to the X-axis direction, the thickness of the layer corresponds to the length along the first direction D1. The configuration in which the first direction D1 is inclined with respect to the X-axis direction may also be applied to any magnetic head according to the embodiment. For example, the interface between the first magnetic pole 31 and the laminate 20 and the interface between the laminate 20 and the second magnetic pole 32 may also be inclined with respect to the X-axis direction.

[0134] Hereinafter, examples of the magnetic head and the magnetic recording medium 80 included in the magnetic recording apparatus 210 of the embodiment will be described.

[0135] Figure 16 FIG. 4 is a schematic perspective view illustrating a magnetic recording apparatus according to an embodiment.

[0136] As shown in Figure 16As shown, a magnetic head (e.g., magnetic head 110) of an embodiment is used together with a magnetic recording medium 80. In this example, the magnetic head 110 includes a recording section 60 and a reproducing section 70. Information is recorded on the magnetic recording medium 80 through the recording section 60 of the magnetic head 110. The information recorded on the magnetic recording medium 80 is reproduced through the reproducing section 70.

[0137] The magnetic recording medium 80 includes, for example, a medium substrate 82 and a magnetic recording layer 81 provided on the medium substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording section 60.

[0138] The reproducing section 70 includes, for example, a first reproducing magnetic shield 72a, a second reproducing magnetic shield 72b, and a magnetic reproducing element 71. The magnetic reproducing element 71 is provided between the first reproducing magnetic shield 72a and the second reproducing magnetic shield 72b. The magnetic reproducing element 71 can output a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0139] As Figure 16 shown, the magnetic recording medium 80 moves relative to the magnetic head 110 in the direction of the medium movement direction 85. Through the magnetic head 110, information corresponding to the magnetization 83 of the magnetic recording layer 81 is controlled at an arbitrary position. Through the magnetic head 110, the information corresponding to the magnetization 83 of the magnetic recording layer 81 is reproduced at an arbitrary position.

[0140] Figure 17 is a schematic perspective view showing a part of a magnetic recording device of an embodiment.

[0141] Figure 17 An example of a head slider is shown.

[0142] The magnetic head 110 is provided on the head slider 159. The head slider 159 contains, for example, Al2O3 / TiC or the like. The head slider 159 moves relative to the magnetic recording medium while floating or contacting on the magnetic recording medium.

[0143] The head slider 159 has, for example, an air inflow side 159A and an air outflow side 159B. The magnetic head 110 is disposed on a side surface of the air outflow side 159B of the head slider 159 or the like. Thus, the magnetic head 110 moves relative to the magnetic recording medium while floating or contacting on the magnetic recording medium.

[0144] Figure 18 is a schematic perspective view showing a magnetic recording device of an embodiment.

[0145] As Figure 18As shown, in the magnetic recording device 150 of the embodiment, a rotary actuator is used. The recording medium disk 180 is assembled to the spindle motor 180M. The recording medium disk 180 rotates in the direction of arrow AR by the spindle motor 180M. The spindle motor 180M responds to a control signal from the drive device control unit. The magnetic recording device 150 of the present embodiment may also include a plurality of recording medium disks 180. The magnetic recording device 150 may also include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). As the recording medium 181, a non-volatile memory such as a flash memory is used, for example. For example, the magnetic recording device 150 may be a hybrid HDD (Hard Disk Drive).

[0146] The head slider 159 performs recording and reproduction of information recorded on the recording medium disk 180. The head slider 159 is provided at the front end of the thin film-like suspension 154. Near the front end of the head slider 159, the magnetic head of the embodiment is provided.

[0147] When the recording medium disk 180 rotates, the pressing pressure obtained based on the suspension 154 balances with the pressure generated on the medium facing surface (ABS) of the head slider 159. The distance between the medium facing surface of the head slider 159 and the surface of the recording medium disk 180 becomes a predetermined floating amount. In the embodiment, the head slider 159 may also be in contact with the recording medium disk 180. For example, a contact moving type may be applied.

[0148] The suspension 154 is connected to one end of the arm 155 (for example, an actuator arm). The arm 155 has, for example, a bobbin portion or the like. The bobbin portion holds the drive coil. At the other end of the arm 155, a voice coil motor 156 is provided. The voice coil motor 156 is a type of linear motor. The voice coil motor 156 includes, for example, a drive coil and a magnetic circuit. The drive coil is wound around the bobbin portion of the arm 155. The magnetic circuit includes a permanent magnet and a relative yoke. The drive coil is provided between the permanent magnet and the relative yoke. The suspension 154 has one end and the other end. The magnetic head is provided at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0149] The arm 155 is held by ball bearings. The ball bearings are provided at two positions, above and below, of the bearing portion 157. The arm 155 can rotate and slide by the voice coil motor 156. The magnetic head can move to any position on the recording medium disk 180.

[0150] Figure 19 (a) and Figure 19 (b) are schematic perspective views illustrating a part of the magnetic recording device of the embodiment.

[0151] Figure 19Example (a) illustrates the configuration of a part of a magnetic recording device and is an enlarged perspective view of a head stack assembly 160. Figure 19 Example (b) is a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA) 158 that is part of the head stack assembly 160.

[0152] As Figure 19 As shown in example (a), the head stack assembly 160 includes a bearing portion 157, a head gimbal assembly 158, and a support frame 161. The head gimbal assembly 158 extends from the bearing portion 157. The support frame 161 extends from the bearing portion 157. The extending direction of the support frame 161 is opposite to the extending direction of the head gimbal assembly 158. The support frame 161 supports the coil 162 of the voice coil motor 156.

[0153] As Figure 19 As shown in example (b), the head gimbal assembly 158 has an arm 155 extending from the bearing portion 157 and a suspension 154 extending from the arm 155.

[0154] At the front end of the suspension 154, a head slider 159 is provided. On the head slider 159, the magnetic head of the embodiment is provided.

[0155] The magnetic head assembly (head gimbal assembly) 158 of the embodiment includes the magnetic head of the embodiment, a head slider 159 provided with the magnetic head, a suspension 154, and an arm 155. The head slider 159 is provided at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0156] The suspension 154 has, for example, leads (not shown) for recording and reproducing signals. The suspension 154 may also have, for example, leads (not shown) for a heater for adjusting the floating amount. The suspension 154 may also have, for example, leads (not shown) for a spin transfer torque oscillator or the like. These leads are electrically connected to a plurality of electrodes provided on the magnetic head.

[0157] In the magnetic recording device 150, a signal processing unit 190 is provided. The signal processing unit 190 uses the magnetic head to record and reproduce signals for the magnetic recording medium. The input / output lines of the signal processing unit 190 are connected, for example, to the electrode pads of the head gimbal assembly 158 and are electrically connected to the magnetic head.

[0158] The magnetic recording device 150 of the embodiment includes a magnetic recording medium, the magnetic head of the embodiment, a movable part, a position control part, and a signal processing part. The movable part can relatively move the magnetic recording medium and the magnetic head in a separated or contacting state. The position control part aligns the magnetic head position with a predetermined recording position of the magnetic recording medium. The signal processing part performs recording and reproduction of signals for the magnetic recording medium using the magnetic head.

[0159] For example, as the above-described magnetic recording medium, a recording medium disk 180 is used. The above-described movable part includes, for example, a head slider 159. The above-described position control part includes, for example, a head gimbal assembly 158.

[0160] The embodiment may also include the following configurations (for example, technical solutions).

[0161] (Configuration 1)

[0162] A magnetic head includes:

[0163] A first magnetic pole;

[0164] A second magnetic pole; and

[0165] A laminate disposed between the first magnetic pole and the second magnetic pole;

[0166] The laminate includes:

[0167] A first magnetic layer;

[0168] A second magnetic layer disposed between the second magnetic pole and the first magnetic layer;

[0169] A third magnetic layer disposed between the second magnetic pole and the second magnetic layer;

[0170] A fourth magnetic layer disposed between the second magnetic pole and the third magnetic layer;

[0171] A first non-magnetic layer disposed between the first magnetic layer and the first magnetic pole;

[0172] A second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer;

[0173] A third non-magnetic layer disposed between the third magnetic layer and the second magnetic layer;

[0174] A fourth non-magnetic layer disposed between the fourth magnetic layer and the third magnetic layer; and

[0175] A fifth non-magnetic layer disposed between the second magnetic pole and the fourth magnetic layer,

[0176] The second non-magnetic layer is in contact with the second magnetic layer and the first magnetic layer,

[0177] The third non-magnetic layer is in contact with the third magnetic layer and the second magnetic layer,

[0178] The fourth non-magnetic layer is in contact with the fourth magnetic layer and the third magnetic layer,

[0179] The fourth thickness of the fourth magnetic layer along the first direction from the first magnetic pole to the second magnetic pole is 0.5 times or more and 1.6 times or less the first thickness of the first magnetic layer along the first direction.

[0180] The second thickness of the second magnetic layer along the first direction is less than the first thickness.

[0181] (Configuration 2)

[0182] According to the magnetic head described in Configuration 1,

[0183] The second thickness is 0.6 times or less the first thickness.

[0184] (Configuration 3)

[0185] According to the magnetic head described in Configuration 2,

[0186] The second thickness is 1 time or less the third thickness of the third magnetic layer along the first direction.

[0187] (Configuration 4)

[0188] According to the magnetic head described in Configuration 3,

[0189] The third thickness is 0.9 times or less the first thickness.

[0190] (Configuration 5)

[0191] According to the magnetic head described in any one of Configurations 1 to 4,

[0192] The first thickness is 5 nm or more and 15 nm or less.

[0193] (Configuration 6)

[0194] According to the magnetic head described in any one of Configurations 1 to 5,

[0195] The second thickness is 5 nm or less.

[0196] (Configuration 7)

[0197] According to the magnetic head described in any one of Configurations 1 to 6,

[0198] The fourth thickness is 5 nm or more and 15 nm or less.

[0199] (Configuration 8)

[0200] According to the magnetic head described in any one of Configurations 1 to 7,

[0201] The distance between the fourth magnetic layer and the first magnetic layer is 5 nm or more and 16 nm or less.

[0202] (Constitution 9)

[0203] The magnetic head according to any one of Constitutions 1 to 8,

[0204] The first non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0205] (Constitution 10)

[0206] The magnetic head according to Constitution 9,

[0207] The second non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0208] (Constitution 11)

[0209] The magnetic head according to Constitution 10,

[0210] The third non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0211] (Constitution 12)

[0212] The magnetic head according to Constitution 11,

[0213] The fourth non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0214] (Constitution 13)

[0215] The magnetic head according to Constitution 12,

[0216] The fifth non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0217] (Constitution 14)

[0218] The magnetic head according to Constitution 13,

[0219] The first non-magnetic layer is in contact with the first magnetic layer and the first magnetic pole.

[0220] (Constitution 15)

[0221] The magnetic head according to Constitution 14,

[0222] The fifth non-magnetic layer is in contact with the second magnetic pole and the fourth magnetic layer.

[0223] (Constitution 16)

[0224] A magnetic head, comprising:

[0225] The first magnetic pole;

[0226] The second magnetic pole; and

[0227] A laminate disposed between the first magnetic pole and the second magnetic pole,

[0228] The laminate includes:

[0229] A first magnetic layer;

[0230] A second magnetic layer disposed between the second magnetic pole and the first magnetic layer;

[0231] A third magnetic layer disposed between the second magnetic pole and the second magnetic layer;

[0232] A fourth magnetic layer disposed between the second magnetic pole and the third magnetic layer;

[0233] A first non-magnetic layer disposed between the first magnetic layer and the first magnetic pole;

[0234] A second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer;

[0235] A third non-magnetic layer disposed between the third magnetic layer and the second magnetic layer;

[0236] A fourth non-magnetic layer disposed between the fourth magnetic layer and the third magnetic layer; and

[0237] A fifth non-magnetic layer disposed between the second magnetic pole and the fourth magnetic layer,

[0238] The second non-magnetic layer is in contact with the second magnetic layer and the first magnetic layer,

[0239] The third non-magnetic layer is in contact with the third magnetic layer and the second magnetic layer,

[0240] The fourth non-magnetic layer is in contact with the fourth magnetic layer and the third magnetic layer,

[0241] The first non-magnetic layer contains Cu,

[0242] The fifth non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0243] (Constitution 17)

[0244] According to the magnetic head described in Constitution 16,

[0245] The second non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0246] The third non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0247] The fourth non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0248] (Constitution 18)

[0249] According to the magnetic head described in Constitution 16 or 17,

[0250] The first non-magnetic layer is in contact with the first magnetic layer and the first magnetic pole.

[0251] The fifth non-magnetic layer is in contact with the second magnetic pole and the fourth magnetic layer.

[0252] (Constitution 19)

[0253] A magnetic recording device includes:

[0254] A magnetic head described in any one of Constitutions 1 to 18; and

[0255] An electric circuit,

[0256] The electric circuit can supply current to the laminate,

[0257] The current has a direction from the first magnetic layer to the second magnetic layer.

[0258] (Constitution 20)

[0259] According to the magnetic recording device described in Constitution 19,

[0260] When the electric circuit supplies the current to the laminate,

[0261] An alternating magnetic field is generated from the laminate.

[0262] According to the embodiment, a magnetic head and a magnetic recording device capable of improving the recording density can be provided.

[0263] In the present specification, "vertical" and "parallel" do not merely refer to strict verticality and strict parallelism, but also include, for example, deviations in manufacturing processes, as long as they are substantially vertical and substantially parallel.

[0264] As described above, the embodiments of the present invention have been explained with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific configurations of various elements such as the magnetic poles, laminates, magnetic layers, non-magnetic layers, and wirings included in the magnetic head, as long as those skilled in the art can appropriately select from the publicly known range and can implement the present invention in the same manner and achieve the same effects, they are included in the scope of the present invention.

[0265] Solutions obtained by combining any two or more elements of each specific example within the technically feasible range, as long as they include the gist of the present invention, are also included in the scope of the present invention.

[0266] In addition, based on the magnetic head and magnetic recording device described above as embodiments of the present invention, all magnetic heads and magnetic recording devices that those skilled in the art can appropriately modify the design and implement, as long as they include the gist of the present invention, also belong to the scope of the present invention.

[0267] In addition, it should be understood that within the scope of the idea of the present invention, various modification examples and correction examples can be conceived by those skilled in the art, and these modification examples and correction examples also belong to the scope of the present invention.

[0268] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their variations are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Claims

1. A magnetic head, comprising: A first magnetic pole; A second magnetic pole; and A laminate disposed between the first magnetic pole and the second magnetic pole, The laminate includes: A first magnetic layer; A second magnetic layer disposed between the second magnetic pole and the first magnetic layer; A third magnetic layer disposed between the second magnetic pole and the second magnetic layer; A fourth magnetic layer disposed between the second magnetic pole and the third magnetic layer; A first non-magnetic layer disposed between the first magnetic layer and the first magnetic pole; A second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer; A third non-magnetic layer disposed between the third magnetic layer and the second magnetic layer; A fourth non-magnetic layer disposed between the fourth magnetic layer and the third magnetic layer; and A fifth non-magnetic layer disposed between the second magnetic pole and the fourth magnetic layer, The second non-magnetic layer is in contact with the second magnetic layer and the first magnetic layer, The third non-magnetic layer is in contact with the third magnetic layer and the second magnetic layer, The fourth non-magnetic layer is in contact with the fourth magnetic layer and the third magnetic layer, The fourth thickness of the fourth magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is 0.5 times or more and 1.6 times or less of the first thickness of the first magnetic layer along the first direction, The second thickness of the second magnetic layer along the first direction is less than the first thickness.

2. The magnetic head according to claim 1, The second thickness is 0.6 times or less of the first thickness.

3. The magnetic head according to claim 2, The second thickness is 1 time or less of the third thickness of the third magnetic layer along the first direction, and the third thickness is 0.9 times or less of the first thickness.

4. The magnetic head according to claim 1, The first non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

5. The magnetic head according to claim 4, The second non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

6. The magnetic head according to claim 5, The third non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

7. The magnetic head according to claim 6, The fourth non-magnetic layer contains at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

8. The magnetic head according to claim 7, The fifth non-magnetic layer contains at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W.

9. A magnetic recording device, comprising: The magnetic head according to claim 1; and An electric circuit, The electric circuit can supply current to the laminate, The current has a direction from the first magnetic layer to the second magnetic layer.

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