Magnetic head and magnetic recording apparatus

Abstract

The invention provides a magnetic head capable of improving characteristics and a magnetic recording apparatus. According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element. The magnetic element is provided between the first magnetic pole and the second magnetic pole in a first direction from the first magnetic pole to the second magnetic pole. The magnetic element includes a first magnetic layer provided between the first magnetic pole and the second magnetic pole, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, and a fourth magnetic layer provided between the third magnetic layer and the second magnetic pole. The first magnetic layer includes a first surface facing the first magnetic pole. The fourth magnetic layer includes a second surface facing the second magnetic pole. A first area of the first surface is larger than a second area of the second surface.

Description

[0001] This application is based on Japanese Patent Application No. 2024-002759 (filing date: January 11, 2024) and claims priority therefrom. This application incorporates the entire contents 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 the magnetic head, improvement in characteristics is desired. Summary of the Invention

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

[0005] Technical Solution for Solving the Problem

[0006] According to an embodiment, the magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element. The magnetic element is disposed between the first magnetic pole and the second magnetic pole in a first direction from the first magnetic pole to the second magnetic pole. The magnetic element includes: a first magnetic layer disposed between the first magnetic pole and the second magnetic pole; a second magnetic layer disposed between the first magnetic layer and the second magnetic pole; a third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and a fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole. The first magnetic layer includes a first surface facing the first magnetic pole. The fourth magnetic layer includes a second surface facing the second magnetic pole. A first area of the first surface is larger than a second area of the second surface.

[0007] With the magnetic head configured as described above, it is possible to provide a magnetic head and a magnetic recording device capable of improving characteristics. Description of the Drawings

[0008] Figure 1 is a schematic plan view illustrating a magnetic head according to a first embodiment.

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

[0010] Figure 3 (a) to Figure 3 (d) are schematic plan views illustrating the operating state of the magnetic head according to the first embodiment.

[0011] Figure 4 is a graph illustrating the characteristics of a magnetic head according to a reference example.

[0012] Figure 5 It is a graph showing the characteristics of the magnetic head.

[0013] Figure 6 It is a graph showing the characteristics of the magnetic head.

[0014] Figure 7 It is a schematic top view showing the magnetic head of the first embodiment.

[0015] Figure 8 It is a schematic top view showing the magnetic head of the first embodiment.

[0016] Figure 9 It is a schematic top view showing the magnetic head of the first embodiment.

[0017] Figure 10 It is a schematic top view showing the magnetic head of the first embodiment.

[0018] Figure 11 It is a graph showing the characteristics of the magnetic head of the first embodiment.

[0019] Figure 12 It is a graph showing the characteristics of the magnetic head of the first embodiment.

[0020] Figure 13 It is a graph showing the characteristics of the magnetic head of the first embodiment.

[0021] Figure 14 It is a graph showing the characteristics of the magnetic head of the first embodiment.

[0022] Figure 15 It is a flowchart showing the operation of the magnetic recording device of the second embodiment.

[0023] Figure 16 It is a flowchart showing the operation of the magnetic recording device of the second embodiment.

[0024] Figure 17 It is a flowchart showing the operation of the magnetic recording device of the second embodiment.

[0025] Figure 18 It is a schematic perspective view showing the magnetic recording device of the embodiment.

[0026] Figure 19 It is a schematic perspective view showing a part of the magnetic recording device of the embodiment.

[0027] Figure 20 It is a schematic perspective view showing the magnetic recording device of the embodiment.

[0028] Figure 21 of (a) and Figure 21Figure (b) is a schematic perspective view of a part of the magnetic recording device according to the exemplary embodiment.

[0029] Explanation of reference numerals

[0030] 20: Magnetic element, 20D: Element circuit, 21 - 25: First magnetic layer - Fifth magnetic layer, 21a, 24a: First end, Second end, 21b, 24b: First other end, Second other end, 30D: Recording circuit, 30F: Medium opposite surface, 30c: Coil, 30i: Insulating portion, 31, 32: First magnetic pole, Second magnetic pole, 33: Shield, 41 - 46: First non-magnetic layer - Sixth non-magnetic layer, 60: Recording portion, 70: Reproducing portion, 71: Magnetic reproducing element, 72a, 72b: First reproducing magnetic shield, Second reproducing magnetic shield, 75: Control portion, 80: Magnetic recording medium, 81: Magnetic recording layer, 82: Medium substrate, 83: Magnetization, 85: Medium moving direction, 110 - 113: Magnetic head, 150: Magnetic recording device, 154: Suspension, 155: Arm, 156: Voice coil motor, 157: Bearing portion, 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 portion, 210 - 213: Magnetic recording device, AR: Arrow, CF1 - CF4: First configuration - Fourth configuration, D1, D2: First direction, Second direction, F1, F2: First surface, Second surface, Hg: Gap magnetic field, Iw: Recording current, Ln1, Ln2: First straight line, Second straight line, OP1, OP2: First operation, Second operation, Rd1: Differential resistance, SR1: Oscillation intensity, T1, T2: First terminal, Second terminal, Tc1, Tc2: First coil terminal, Second coil terminal, Va1: Voltage, Ve1, Ve2: First voltage range, Second voltage range, Vn1: First negative peak voltage, Vp1, Vp2: First positive peak voltage, Second positive peak voltage, W1, W2: First wiring, Second wiring, ic: Element current, je: Electron flow, n1: First negative peak, p1, p2: First positive peak, Second positive peak, t21 - t25: First thickness - Fifth thickness, t41 - t46: Thickness, tm: Time, θ1, θ2: First angle, Second angle Detailed implementation mode

[0031] (First embodiment)

[0032] Figure 1 Figure is a schematic top view of the magnetic head according to the first embodiment.

[0033] Figure 2It is a schematic cross-sectional view illustrating a magnetic recording apparatus including a magnetic head according to the first embodiment.

[0034] As Figure 2 shown, the magnetic recording apparatus 210 of the embodiment includes a magnetic head 110 and a magnetic recording medium 80. The magnetic recording apparatus 210 may further include a control unit 75. In the magnetic recording apparatus 210, at least a recording operation is performed. In the recording operation, information is recorded on the magnetic recording medium 80 using the magnetic head 110.

[0035] The magnetic head 110 includes a recording unit 60. As described later, the magnetic head 110 may also include a reproducing unit. The recording unit 60 includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20. The recording unit 60 may further include a coil 30c. The magnetic element 20 is disposed between the first magnetic pole 31 and the second magnetic pole 32.

[0036] 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.

[0037] The direction from the magnetic recording medium 80 to the magnetic head 110 is defined as the Z-axis direction. One direction perpendicular to the Z-axis direction is defined as the X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is defined as the Y-axis direction. The Z-axis direction corresponds, for example, to the height direction. The X-axis direction corresponds, for example, to the down-track direction. The Y-axis direction corresponds, for example, to the cross-track direction. Along the down-track direction, the magnetic recording medium 80 moves relative to the magnetic head 110. At a desired position of the magnetic recording medium 80, a recording magnetic field generated from the magnetic head 110 is applied. The magnetization at the desired position of the magnetic recording medium 80 is controlled to a direction corresponding to the recording magnetic field. Thereby, information is recorded on the magnetic recording medium 80.

[0038] The direction from the first magnetic pole 31 to the second magnetic pole 32 is defined 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 with respect to the X-axis direction. The inclined angle is, for example, more than 0 degrees and 10 degrees or less.

[0039] 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).

[0040] As shown Figure 2 As shown, a recording current Iw is supplied from a recording circuit 30D to a coil 30c. For example, a first coil terminal Tc1 and a second coil terminal Tc2 are provided in the coil 30c. Through these coil terminals, the recording current Iw is supplied to the coil 30c. A recording magnetic field corresponding to the recording current Iw is applied from a first magnetic pole 31 to a magnetic recording medium 80.

[0041] As shown Figure 2 As 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.

[0042] As shown Figure 2 As shown, an element circuit 20D is electrically connected to a magnetic element 20. In this example, the magnetic element 20 is electrically connected to the first magnetic pole 31 and the second magnetic pole 32. A first terminal T1 and a second terminal T2 are provided in a magnetic head 110. The first terminal T1 is electrically connected to one end of the magnetic element 20 through a first wiring W1 and the first magnetic pole 31. The second terminal T2 is electrically connected to the other end of the magnetic element 20 through a second wiring W2 and the second magnetic pole 32. An element current ic is supplied from the element circuit 20D to the magnetic element 20, for example.

[0043] As shown Figure 2 As shown, in one operation state, the element current ic has a direction from the first magnetic pole 31 to the second magnetic pole 32. In this case, an electron flow je accompanying the element current ic has a direction from the second magnetic pole 32 to the first magnetic pole 31. The element current ic is, for example, a direct current. As described later, in another operation state, the element current ic has a direction from the second magnetic pole 32 to the first magnetic pole 31. In this case, the electron flow je has a direction from the first magnetic pole 31 to the second magnetic pole 32.

[0044] For example, when an element current ic above a threshold value flows through the magnetic element 20, oscillation is generated in a magnetic layer included in the magnetic element 20. The magnetic element 20 functions as an STO (Spin-Torque Oscillator), for example. Along with the oscillation, an alternating magnetic field (for example, a high-frequency magnetic field) is generated from the magnetic element 20. The alternating magnetic field generated by the magnetic element 20 is applied to the magnetic recording medium 80 to assist recording on the magnetic recording medium 80. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented.

[0045] A control unit 75 controls the recording circuit 30D and the element circuit 20D.

[0046] As shown Figure 1 As shown, the magnetic element 20 includes a first magnetic layer 21, a second magnetic layer 22, a third magnetic layer 23, and a fourth magnetic layer 24. 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 first magnetic layer 21 and the second magnetic pole 32. The third magnetic layer 23 is disposed between the second magnetic layer 22 and the second magnetic pole 32. The fourth magnetic layer 24 is disposed between the third magnetic layer 23 and the second magnetic pole 32.

[0047] The magnetic element 20 may include 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. The first non-magnetic layer 41 is disposed between the first magnetic pole 31 and the first magnetic layer 21. The second non-magnetic layer 42 is disposed between the first magnetic layer 21 and the second magnetic layer 22. The third non-magnetic layer 43 is disposed between the second magnetic layer 22 and the third magnetic layer 23. The fourth non-magnetic layer 44 is disposed between the third magnetic layer 23 and the fourth magnetic layer 24. The fifth non-magnetic layer 45 is disposed between the fourth magnetic layer 24 and the second magnetic pole 32.

[0048] As shown Figure 1 As shown, the first magnetic layer 21 includes a first surface F1 opposite to the first magnetic pole 31. The fourth magnetic layer 24 includes a second surface F2 opposite to the second magnetic pole 32. In an embodiment, a first area of the first surface F1 is larger than a second area of the second surface F2.

[0049] For example, a side surface of the magnetic element 20 is inclined with respect to a first direction D1. As shown Figure 2 As shown, the first magnetic pole 31 includes a dielectric opposite surface 30F. As shown Figure 1 As shown, a first length L1 of the first surface F1 along a second direction D2 is longer than a second length L2 of the second surface F2 along the second direction D2. The second direction D2 is along the dielectric opposite surface 30F and is orthogonal to the first direction D1. The second direction D2 is, for example, the Y-axis direction. The above-mentioned difference in area can be generated by such a difference in length.

[0050] As will be described later, due to such a difference in area (or, difference in length), in the magnetic element 20, a high-speed magnetization reversal can be obtained. A high-speed writing operation can be implemented. According to the embodiment, a magnetic head capable of improving characteristics can be provided. For example, a high recording density can be obtained.

[0051] As shown Figure 1As shown, the first surface F1 includes a first end 21a and a first other end 21b. The direction from the first other end 21b to the first end 21a is along the second direction D2. The second surface F2 includes a second end 24a and a second other end 24b. The direction from the second other end 24b to the second end 24a is along the second direction D2. The distance between the first end 21a and the second end 24a is shorter than the distance between the first end 21a and the second other end 24b. The first end 21a and the second end 24a are ends on the same side in the second direction D2. The first other end 21b and the second other end 24b are ends on the same side in the second direction D2.

[0052] Let the straight line passing through the first end 21a and the second end 24a be the first straight line Ln1. The first straight line Ln1 is inclined with respect to the direction perpendicular to the first surface F1 (the first direction D1). Let the angle between the first straight line Ln1 and the direction perpendicular to the first surface F1 (the first direction D1) be the first angle θ1. The first angle θ1 is greater than 0.

[0053] Let the straight line passing through the first other end 21b and the second other end 24b be the second straight line Ln2. The second straight line Ln2 is inclined with respect to the direction perpendicular to the first surface F1 (the first direction D1). Let the angle between the second straight line Ln2 and the direction perpendicular to the second surface F2 (the first direction D1) be the second angle θ2. The second angle θ2 is greater than 0.

[0054] The above-mentioned area difference and the above-mentioned length difference can be generated by such a first angle θ1 and a second angle θ2. The second angle θ2 can be substantially the same as the first angle θ1. In the embodiment, the first angle θ1 can be, for example, 5 degrees or more and 15 degrees or less. The second angle θ2 can be, for example, 5 degrees or more and 15 degrees or less.

[0055] Hereinafter, an example of the operation of the magnetic head 110 will be described.

[0056] Figure 3 of (a) to Figure 3 of (d) are schematic top views illustrating the operation states of the magnetic head according to the first embodiment.

[0057] In the magnetic head 110, a first operation OP1 and a second operation OP2 are performed. In the first operation OP1, the element current ic flows from the first magnetic pole 31 to the second magnetic pole 32. In the second operation OP2, the element current ic flows from the second magnetic pole 32 to the first magnetic pole 31. In both the first operation OP1 and the second operation OP2, the magnetization of the magnetic element 20 oscillates.

[0058] On the other hand, a gap magnetic field Hg is generated between the first magnetic pole 31 and the second magnetic pole 32 by a recording magnetic field based on a recording current Iw supplied to the coil 30c. According to the information to be recorded, the direction of the recording current Iw changes. As a result, the direction of the gap magnetic field Hg changes.

[0059] In Figure 3 In the first configuration CF1 shown in (a) of Figure 3 in the first operation OP1, the gap magnetic field Hg has a direction from the second magnetic pole 32 to the first magnetic pole 31. In Figure 3 In the second configuration CF2 shown in (b) of Figure 3 in the first operation OP1, the gap magnetic field Hg has a direction from the first magnetic pole 31 to the second magnetic pole 32. In

[0060] In the third configuration CF3 shown in (c) of

[0061] Figure 4 is a graph illustrating the characteristics of the head of the reference example.

[0062] Figure 4 The simulation results of the characteristics of the head 119 of the reference example are illustrated. In the head 119, the first angle θ1 and the second angle θ2 are 0, and the first area of the first surface F1 is the same as the second area of the second surface F2. Figure 4 The horizontal axis of

[0063] is the time tm. The vertical axis is the oscillation intensity SR1 (relative value) of the magnetic layer.

[0064] As Figure 4 shown, in the first operation OP1 and the second operation OP2, the oscillation intensity SR1 is low when the time tm is about 0.2 ns. When the time tm is 0.6 ns or more, a high oscillation intensity SR1 can be obtained. In this example, for example, the switching time is about 0.6 ns.

[0065] In the time range where the time tm is 0 ns or more and 0.5 ns or less, in the first operation OP1, the oscillation intensity SR1 is low. On the other hand, in this time range, in the second operation OP2, an oscillation intensity SR1 higher than that in the first operation OP1 can be obtained. In the time range where the time tm is 0.6 ns or more, the oscillation intensity SR1 in the first operation OP1 is higher than the oscillation intensity SR1 in the second operation OP2.

[0066] Thus, in the second operation OP2, although a relatively high oscillation intensity SR1 can be obtained in the initial stage of switching, the oscillation intensity SR1 is low after a long time from the switching. In contrast, in the first operation OP1, although the oscillation intensity SR1 is low in the initial stage of switching, a high oscillation intensity SR1 can be obtained after a long time from the switching.

[0067] Hereinafter, an example of the simulation result of the oscillation intensity SR1 when changing the first angle θ1 will be described. In the following example, the second angle θ2 is the same as the first angle θ1.

[0068] Figure 5 and Figure 6 are diagrams illustrating the characteristics of the magnetic head.

[0069] The horizontal axis of these diagrams is the first angle θ1. When the first angle θ1 is positive, the first area of the first surface F1 is larger than the second area of the second surface F2. When the first angle θ1 is negative, the side surface of the magnetic element 20 shows the opposite inclination, and the first area of the first surface F1 is smaller than the second area of the second surface F2. In Figure 5 , the time tm is 0.375 ns. In Figure 6 , the time tm is 0.875 ns.

[0070] As Figure 5 shows, by making the first angle θ1 greater than 0 degrees, the oscillation intensity SR1 in the second operation OP2 becomes higher. On the other hand, the oscillation intensity SR1 in the first operation OP1 does not change significantly with the change of the first angle θ1. When the first angle θ1 is greater than 5 degrees, in the second operation OP2, a high oscillation intensity SR1 can be effectively obtained. The first angle θ1 is preferably 5 degrees or more, for example.

[0071] As Figure 6 shows, in this example, by making the first angle θ1 greater than 0 degrees, the oscillation intensity SR1 in the second operation OP2 becomes higher. On the other hand, the oscillation intensity SR1 in the first operation OP1 decreases when the first angle θ1 exceeds 15 degrees. In the embodiment, the first angle θ1 is preferably 15 degrees or less.

[0072] When the first angle θ1 is 5 degrees or more and 15 degrees or less, high oscillation intensity SR1 can be obtained in the first operation OP1 and the second operation OP2.

[0073] When the first angle θ1 is greater than 0, the oscillation intensity SR1 rises in the second operation OP2 at time tm = 0.375 ns, which is considered to be because the current density in the multiple magnetic layers included in the magnetic element 20 is appropriately controlled.

[0074] For example, when the first angle θ1 is greater than 0, the current density in the third magnetic layer 23 becomes higher than the current density in the first magnetic layer 21. Thus, for example, it is easy to quickly generate oscillation of the magnetization of the third magnetic layer 23 after switching. For example, since the current density in the first magnetic layer 21 is low, it is difficult for the magnetization of the first magnetic layer 21 to move, suppressing the case of "hindering the oscillation of the third magnetic layer 23". For example, regarding the oscillation intensity SR1 in the second operation OP2, the contribution of the oscillation of the magnetization of the third magnetic layer 23 is large.

[0075] Hereinafter, several examples of the configuration of the magnetic element 20 will be described.

[0076] Figures 7 - 10 It is a schematic top view illustrating the magnetic head of the first embodiment.

[0077] As Figure 7 shown, in the magnetic head 110 of the embodiment, the magnetic element 20 includes 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.

[0078] In the magnetic head 110, the first non-magnetic layer 41 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The second non-magnetic layer 42 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. The third non-magnetic layer 43 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The fourth non-magnetic layer 44 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The fifth non-magnetic layer 45 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0079] As Figure 1 shown, the thickness of the first magnetic layer 21 along the first direction D1 is defined as the first thickness t21. The thickness of the second magnetic layer 22 along the first direction D1 is defined as the second thickness t22. The thickness of the third magnetic layer 23 along the first direction D1 is defined as the third thickness t23. The thickness of the fourth magnetic layer 24 along the first direction D1 is defined as the fourth thickness t24.

[0080] In the magnetic head 110, the first thickness t21 is thicker than the second thickness t22. The third thickness t23 is thicker than the fourth thickness t24. The first thickness t21 is, for example, 3 nm or more and 15 nm or less. The first thickness t21 can also be, for example, 5 nm or more and 15 nm or less. The second thickness t22 is, for example, 1 nm or more and 8 nm or less. The second thickness t22 can also be, for example, 1 nm or more and 4 nm or less. The third thickness t23 is, for example, 3 nm or more and 15 nm or less. The third thickness t23 can also be, for example, 5 nm or more and 15 nm or less. The fourth thickness t24 is, for example, 1 nm or more and 8 nm or less. The fourth thickness t24 can also be, for example, 1 nm or more and 4 nm or less.

[0081] In Figure 8 In the magnetic head 111 of the illustrated embodiment, the first nonmagnetic layer 41 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The second nonmagnetic layer 42 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The third nonmagnetic layer 43 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth nonmagnetic layer 44 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The fifth nonmagnetic layer 45 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0082] In the magnetic head 111, the first thickness t21 is thicker than the second thickness t22. The third thickness t23 is thicker than the fourth thickness t24. The first thickness t21 is, for example, 3 nm or more and 15 nm or less. The first thickness t21 can also be, for example, 5 nm or more and 15 nm or less. The second thickness t22 is, for example, 1 nm or more and 8 nm or less. The second thickness t22 can also be, for example, 1 nm or more and 4 nm or less. The third thickness t23 is, for example, 3 nm or more and 15 nm or less. The third thickness t23 can also be, for example, 5 nm or more and 15 nm or less. The fourth thickness t24 is, for example, 1 nm or more and 8 nm or less. The fourth thickness t24 can also be, for example, 1 nm or more and 4 nm or less.

[0083] In Figure 9 In the magnetic head 112 of the illustrated embodiment, the first nonmagnetic layer 41 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The second nonmagnetic layer 42 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The third nonmagnetic layer 43 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth nonmagnetic layer 44 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The fifth nonmagnetic layer 45 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0084] In the magnetic head 112, the first thickness t21 is thicker than the second thickness t22. The third thickness t23 is thinner than the fourth thickness t24. The first thickness t21 is, for example, 3 nm or more and 15 nm or less. The first thickness t21 may also be, for example, 5 nm or more and 15 nm or less. The second thickness t22 is, for example, 1 nm or more and 8 nm or less. The second thickness t22 may also be, for example, 1 nm or more and 4 nm or less. The third thickness t23 is, for example, 1 nm or more and 8 nm or less. The third thickness t23 may also be, for example, 1 nm or more and 4 nm or less. The fourth thickness t24 is, for example, 3 nm or more and 15 nm or less. The fourth thickness t24 may also be, for example, 5 nm or more and 15 nm or less.

[0085] In the magnetic heads 110, 111, and 112, the first nonmagnetic layer 41 is in contact with the first magnetic pole 31 and the first magnetic layer 21. The second nonmagnetic layer 42 is in contact with the first magnetic layer 21 and the second magnetic layer 22. The third nonmagnetic layer 43 is in contact with the second magnetic layer 22 and the third magnetic layer 23. The fourth nonmagnetic layer 44 is in contact with the third magnetic layer 23 and the fourth magnetic layer 24. The fifth nonmagnetic layer 45 is in contact with the fourth magnetic layer 24 and the second magnetic pole 32.

[0086] In Figure 10 In the magnetic head 113 of the illustrated embodiment, the magnetic element 20 further includes a fifth magnetic layer 25 and a sixth nonmagnetic layer 46. The configuration of the magnetic head 113 other than these may be the same as that of the magnetic head 110 or the like, for example.

[0087] In the magnetic head 113, the fifth magnetic layer 25 is disposed between the third nonmagnetic layer 43 and the third magnetic layer 23. The sixth nonmagnetic layer 46 is disposed between the fifth magnetic layer 25 and the third magnetic layer 23.

[0088] In the magnetic head 113, the first nonmagnetic layer 41 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The second nonmagnetic layer 42 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The third nonmagnetic layer 43 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. The fourth nonmagnetic layer 44 contains at least one selected from Cu, Au, Cr, V, Al, and Ag. The fifth nonmagnetic layer 45 contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. The sixth nonmagnetic layer 46 contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0089] As Figure 10 shown, in the magnetic head 113, the thickness of the fifth magnetic layer 25 along the first direction D1 is defined as the fifth thickness t25. As Figure 1Define the first thickness t21, the second thickness t22, the third thickness t23, and the fourth thickness t24 as shown. In the magnetic head 113, the first thickness t21 is thicker than the second thickness t22. The third thickness t23 is thicker than the fourth thickness t24. The fifth thickness t25 is thinner than the third thickness t23. The first thickness t21 is, for example, 3 nm or more and 15 nm or less. The first thickness t21 can also be, for example, 5 nm or more and 15 nm or less. The second thickness t22 is, for example, 1 nm or more and 8 nm or less. The second thickness t22 can also be, for example, 1 nm or more and 4 nm or less. The third thickness t23 is, for example, 3 nm or more and 15 nm or less. The third thickness t23 can also be, for example, 5 nm or more and 15 nm or less. The fourth thickness t24 is, for example, 1 nm or more and 8 nm or less. The fourth thickness t24 can also be, for example, 1 nm or more and 4 nm or less. The fifth thickness t25 is, for example, 1 nm or more and 8 nm or less. The fifth thickness t25 can also be, for example, 1 nm or more and 4 nm or less.

[0090] In the magnetic heads 111, 112, and 113, the configuration described for the magnetic head 110 can be applied. For example, the first area of the first surface F1 is larger than the second area of the second surface F2. For example, the first length L1 is longer than the second length L2. The first angle θ1 is 5 degrees or more and 15 degrees or less. The second angle θ2 is 5 degrees or more and 15 degrees or less.

[0091] In the magnetic heads 110 to 113, the thickness t41 of the first non-magnetic layer 41 (refer to Figure 1 ) is, for example, 0.5 nm or more and 6 nm or less. The thickness t42 of the second non-magnetic layer 42 (refer to Figure 1 ) is, for example, 0.5 nm or more and 10 nm or less. The thickness t43 of the third non-magnetic layer 43 (refer to Figure 1 ) is, for example, 0.5 nm or more and 10 nm or less. The thickness t44 of the fourth non-magnetic layer 44 (refer to Figure 1 ) is, for example, 0.5 nm or more and 6 nm or less. The thickness t45 of the fifth non-magnetic layer 45 (refer to Figure 1 ) is, for example, 1 nm or more and 10 nm or less. The thickness t46 of the sixth non-magnetic layer 46 (refer to Figure 10 ) is, for example, 0.5 nm or more and 6 nm or less.

[0092] In the embodiment, the first operation OP1 and the second operation OP2 can be implemented. These operations can be switched and implemented. In the first operation OP1, the element current ic supplied between the first magnetic pole 31 and the second magnetic pole 32 flows from the first magnetic pole 31 to the second magnetic pole 32. In the second operation OP2, the element current ic flows from the second magnetic pole 32 to the first magnetic pole 31.

[0093] Next, the differential resistance of the magnetic element 20 when the voltage Va1 applied to the magnetic element 20 is changed is exemplified.

[0094] Figures 11 - 14 It is a graph exemplifying the characteristics of the magnetic head of the first embodiment.

[0095] The horizontal axis of these graphs is the voltage Va1 applied to the magnetic element 20. The vertical axis is the differential resistance Rd1 of the magnetic element 20. The voltage Va1 can be the voltage between the first terminal T1 and the second terminal T2. For example, a voltage corresponding to the voltage Va1 is applied to the magnetic element 20.

[0096] When the voltage Va1 is positive, the potential of the first magnetic pole 31 is higher than the potential of the second magnetic pole 32. When the voltage Va1 is negative, the potential of the first magnetic pole 31 is lower than the potential of the second magnetic pole 32. When the voltage Va1 is positive, the first operation OP1 is performed. When the voltage Va1 is negative, the second operation OP2 is performed.

[0097] As Figure 11 shown, in the magnetic head 110, the differential resistance Rd1 when the voltage Va1 is changed includes a plurality of peaks. These peaks are considered to correspond to discontinuous changes in resistance accompanying the reversal of magnetization of the plurality of magnetic layers included in the magnetic element 20.

[0098] In the magnetic head 110, the plurality of peaks include a first negative peak n1 and a first positive peak p1. The voltage Va1 corresponding to the first negative peak n1 is the first negative peak voltage Vn1. The voltage Va1 corresponding to the first positive peak p1 is the first positive peak voltage Vp1. In the first operation OP1, the voltage Va1 is in the first voltage range Ve1. The first voltage range Ve1 is, for example, higher than the first positive peak voltage Vp1. In the second operation OP2, the voltage Va1 is in the second voltage range Ve2. The second voltage range Ve2 is, for example, lower than the first negative peak voltage Vn1.

[0099] Figure 12 Corresponding to the magnetic head 111. In the magnetic head 111, the plurality of peaks include a first positive peak p1 and a second positive peak p2. The voltage Va1 corresponding to the second positive peak p2 is the second positive peak voltage Vp2. The second positive peak voltage Vp2 is higher than the first positive peak voltage Vp1. In the first operation OP1, the voltage Va1 is in the first voltage range Ve1. The first voltage range Ve1 is, for example, higher than the second positive peak voltage Vp2.

[0100] Figure 13Corresponding to the magnetic head 112. In the magnetic head 112, a plurality of peaks include the first negative peak n1 and the first positive peak p1. In the first operation OP1, the voltage Va1 is within the first voltage range Ve1. The first voltage range Ve1 is higher than the first positive peak voltage Vp1. In the second operation OP2, the voltage Va1 is within the second voltage range Ve2. The second voltage range Ve2 is, for example, lower than the first negative peak voltage Vn1.

[0101] Figure 14 Corresponding to the magnetic head 113. In the magnetic head 113, a plurality of peaks include the first negative peak n1, the first positive peak p1, and the second positive peak p2. In the first operation OP1, the voltage Va1 is within the first voltage range Ve1. The first voltage range Ve1 is, for example, higher than the second positive peak voltage Vp2. In the second operation OP2, the voltage Va1 is within the second voltage range Ve2. The second voltage range Ve2 is, for example, lower than the first negative peak voltage Vn1.

[0102] (Second Embodiment)

[0103] The second embodiment relates to a magnetic recording device 210. The magnetic recording device 210 includes a magnetic head, a magnetic recording medium 80, an element circuit 20D, and a control unit 75. The magnetic head is configured to record information on the magnetic recording medium 80.

[0104] In the second embodiment, the magnetic head may, for example, have a configuration exemplified by any one of Figures 7 - 10 . The magnetic head includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20 disposed between the first magnetic pole 31 and the second magnetic pole 32. The magnetic element 20 includes: a first magnetic layer 21 disposed between the first magnetic pole 31 and the second magnetic pole 32, a second magnetic layer 22 disposed between the first magnetic layer 21 and the second magnetic pole 32, a third magnetic layer 23 disposed between the second magnetic layer 22 and the second magnetic pole 32, and a fourth magnetic layer 24 disposed between the third magnetic layer 23 and the second magnetic pole 32. The magnetic element 20 may include 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. The magnetic element 20 may further include a fifth magnetic layer 25 and a sixth non-magnetic layer 46 (see Figure 10 ).

[0105] The element circuit 20D is configured to supply an element current ic between the first magnetic pole 31 and the second magnetic pole 32. The element circuit 20D is configured to perform the first operation OP1 and the second operation OP2. In the first operation OP1, the element current ic flows from the first magnetic pole 31 to the second magnetic pole 32. In the second operation OP2, the element current ic flows from the second magnetic pole 32 to the first magnetic pole 31.

[0106] In the first operation OP1 and the second operation OP2, information regarding Figure 4The described characteristics. In the first operation OP1, although the initial oscillation strength SR1 is low at the beginning of the switching, a high oscillation strength SR1 can be obtained after a long time from the switching. In the second operation OP2, although a relatively high oscillation strength SR1 can be obtained at the beginning of the switching, the oscillation strength SR1 is low after a long time from the switching. Based on the recording conditions suitable for such characteristics, the first operation OP1 or the second operation OP2 is switched and implemented.

[0107] In the second embodiment, in the magnetic element 20, the first area of the first surface F1 may be the same as the second area of the second surface F2. The first area may be larger than the second area. The first area may also be smaller than the second area. In the second embodiment, the operation of the control unit 75 is changed according to the recording conditions.

[0108] Figure 15 It is a flowchart exemplifying the operation of the magnetic recording device of the second embodiment.

[0109] As Figure 15 shown, in the magnetic recording device 211 of the embodiment, the control unit 75 determines whether the recording position on the magnetic recording medium 80 is closer to the inside than the determined position (step S11). When the recording position on the magnetic recording medium 80 is closer to the inside than the determined position, the control unit 75 causes the element circuit 20D to perform the first operation OP1 (step S21). When the recording position on the magnetic recording medium 80 is not closer to the inside than the determined position, the control unit 75 causes the element circuit 20D to perform the second operation OP2 (step S22).

[0110] The magnetic recording medium 80 is disk-shaped. When the recording position is inside, the first operation OP1 is performed. When the recording position is outside, the second operation OP2 is performed. Thereby, recording with a high recording density can be performed at high speed.

[0111] Figure 16 It is a flowchart exemplifying the operation of the magnetic recording device of the second embodiment.

[0112] As Figure 16 shown, in the magnetic recording device 212 of the embodiment, the control unit 75 determines whether the recording density in the circumferential direction is lower than the determined density Vd1 (step S12). When the recording density in the circumferential direction is lower than the determined density Vd1, the control unit 75 causes the element circuit 20D to perform the first operation OP1 (step S21). When the recording density in the circumferential direction is not lower than the determined density Vd1, the control unit 75 causes the element circuit 20D to perform the second operation OP2 (step S22).

[0113] For example, in the case of low BPI (Bits per Inch), the first operation OP1 is performed. For example, in the case of high BPI, the second operation OP2 is performed. Thus, high-density recording can be performed at high speed.

[0114] Figure 17 It is a flowchart illustrating the operation of the magnetic recording device according to the second embodiment.

[0115] As Figure 17 shown, in the magnetic recording device 213 of the embodiment, the control unit 75 determines whether to perform shingled magnetic recording (SMR) (step S13). When the control unit 75 performs shingled magnetic recording, it causes the element circuit 20D to perform the first operation OP1 (step S21). When the control unit 75 performs a recording that is not shingled magnetic recording, it causes the element circuit 20D to perform the second operation OP2 (step S22).

[0116] For example, in the case of performing shingled magnetic recording, the first operation OP1 is performed. For example, in the case of performing CMR recording (Conventional Magnetic Recording), the second operation OP2 is performed. Thus, high-density recording can be performed at high speed.

[0117] Hereinafter, examples of other configurations of the magnetic recording device according to the embodiment will be described.

[0118] Figure 18 It is a schematic perspective view illustrating the magnetic recording device according to the embodiment.

[0119] As Figure 18 shown, the magnetic head (for example, the magnetic head 110) according to the embodiment is used together with the magnetic recording medium 80. In this example, the magnetic head 110 includes a recording unit 60 and a reproducing unit 70. Information is recorded on the magnetic recording medium 80 through the recording unit 60 of the magnetic head 110. The information recorded on the magnetic recording medium 80 is reproduced through the reproducing unit 70.

[0120] 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 unit 60.

[0121] The reproducing unit 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.

[0122] As shown Figure 18 in FIG. 1, the magnetic recording medium 80 moves relative to the magnetic head 110 in the direction of the medium movement direction 85. Information corresponding to the magnetization 83 of the magnetic recording layer 81 is controlled at an arbitrary position by the magnetic head 110. Information corresponding to the magnetization 83 of the magnetic recording layer 81 is reproduced at an arbitrary position by the magnetic head 110.

[0123] Figure 19 FIG. 2 is a schematic perspective view of a part of the magnetic recording apparatus according to the exemplary embodiment.

[0124] Figure 19 The head slider is illustrated.

[0125] The magnetic head 110 is provided on the head slider 159. The head slider 159 includes, for example, Al2O3 / TiC or the like. The head slider 159 moves relative to the magnetic recording medium while floating or contacting the magnetic recording medium.

[0126] 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 the 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 the magnetic recording medium.

[0127] Figure 20 FIG. 3 is a schematic perspective view of the magnetic recording apparatus according to the exemplary embodiment.

[0128] Figure 21 FIG. 4(a) and Figure 21 FIG. 4(b) are schematic perspective views of a part of the magnetic recording apparatus according to the exemplary embodiment.

[0129] As shown Figure 20 in FIG. 5, in the magnetic recording apparatus 150 of the embodiment, a rotary actuator is used. The recording medium disk 180 is mounted on the spindle motor 180M. The recording medium disk 180 rotates in the direction of the 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 apparatus 150 of the present embodiment may also include a plurality of recording medium disks 180. The magnetic recording apparatus 150 may also include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). For the recording medium 181, a non-volatile memory such as a flash memory is used, for example. For example, the magnetic recording apparatus 150 may be a hybrid HDD (Hard Disk Drive).

[0130] The head slider 159 records and reproduces information recorded on the recording medium disk 180. The head slider 159 is provided at the front end of the thin-film suspension 154. A magnetic head of the embodiment is provided near the front end of the head slider 159.

[0131] When the recording medium disk 180 rotates, the pressing pressure generated by the suspension 154 and the pressure generated on the medium facing surface (ABS) of the head slider 159 are balanced. 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.

[0132] The suspension 154 is connected to one end of the arm 155 (e.g., actuator arm). The arm 155 has, for example, a bobbin portion. The bobbin portion holds the drive coil. A voice coil motor 156 is provided at the other end of the arm 155. 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.

[0133] The arm 155 is held by ball bearings. The ball bearings are provided at two upper and lower positions of the bearing portion 157. The arm 155 can rotate and slide through the voice coil motor 156. The magnetic head can move to any position on the recording medium disk 180.

[0134] Figure 21 Example (a) illustrates the configuration of a part of the magnetic recording device and is an enlarged perspective view of the head stack assembly 160.

[0135] Figure 21 Example (b) is a perspective view illustrating the magnetic head assembly (head gimbal assembly: HGA) 158 which is a part of the head stack assembly 160.

[0136] As Figure 21 shown in (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.

[0137] As Figure 21 shown in (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.

[0138] A head slider 159 is provided at the front end of the suspension 154. A magnetic head of the embodiment is provided on the head slider 159.

[0139] 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.

[0140] 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 floating amount adjustment. The suspension 154 may also have, for example, leads (not shown) for an oscillation element or the like. These leads are electrically connected to a plurality of electrodes provided on the magnetic head.

[0141] 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 to and from 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.

[0142] 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 move the magnetic recording medium and the magnetic head relative to each other in a separated or contacting state. The position control part aligns the position of the magnetic head to a predetermined recording position on the magnetic recording medium. The signal processing part performs recording and reproduction of signals to and from the magnetic recording medium using the magnetic head.

[0143] For example, as the above magnetic recording medium, a recording medium disk 180 is used. The above movable part includes, for example, the head slider 159. The above position control part includes, for example, the head gimbal assembly 158.

[0144] The embodiment may also include the following technical solutions.

[0145] (Technical solution 1)

[0146] A magnetic head includes:

[0147] A first magnetic pole;

[0148] A second magnetic pole; and

[0149] A magnetic element disposed between the first magnetic pole and the second magnetic pole in a first direction from the first magnetic pole to the second magnetic pole,

[0150] The magnetic element includes:

[0151] The first magnetic layer is disposed between the first magnetic pole and the second magnetic pole;

[0152] The second magnetic layer is disposed between the first magnetic layer and the second magnetic pole;

[0153] The third magnetic layer is disposed between the second magnetic layer and the second magnetic pole; and

[0154] The fourth magnetic layer is disposed between the third magnetic layer and the second magnetic pole,

[0155] The first magnetic layer includes a first surface opposite to the first magnetic pole,

[0156] The fourth magnetic layer includes a second surface opposite to the second magnetic pole,

[0157] A first area of the first surface is larger than a second area of the second surface.

[0158] (Technical solution 2)

[0159] The magnetic head according to technical solution 1,

[0160] The first magnetic pole includes a medium-facing surface,

[0161] A first length of the first surface along a second direction is longer than a second length of the second surface along the second direction,

[0162] The second direction is along the medium-facing surface and orthogonal to the first direction.

[0163] (Technical solution 3)

[0164] The magnetic head according to technical solution 2,

[0165] The first surface includes a first end and a first other end,

[0166] The direction from the first other end to the first end is along the second direction,

[0167] The second surface includes a second end and a second other end,

[0168] The direction from the second other end to the second end is along the second direction,

[0169] The distance between the first end and the second end is shorter than the distance between the first end and the second other end,

[0170] A first angle between a first straight line passing through the first end and the second end and a direction perpendicular to the first surface is 5 degrees or more and 15 degrees or less.

[0171] (Technical solution 4)

[0172] The magnetic head according to Technical Solution 3

[0173] The second angle between the second straight line passing through the second ends of the first and the second and the direction perpendicular to the first surface is 5 degrees or more and 15 degrees or less.

[0174] (Technical Solution 5)

[0175] The magnetic head according to any one of Technical Solutions 1 to 4

[0176] The magnetic element further includes:

[0177] A first non-magnetic layer disposed between the first magnetic pole and the first magnetic layer;

[0178] A second non-magnetic layer disposed between the first magnetic layer and the second magnetic layer;

[0179] A third non-magnetic layer disposed between the second magnetic layer and the third magnetic layer;

[0180] A fourth non-magnetic layer disposed between the third magnetic layer and the fourth magnetic layer; and

[0181] A fifth non-magnetic layer disposed between the fourth magnetic layer and the second magnetic pole.

[0182] (Technical Solution 6)

[0183] The magnetic head according to Technical Solution 5

[0184] The first non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0185] The second non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W,

[0186] The third non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0187] The fourth non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0188] The fifth non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0189] (Technical Solution 7)

[0190] The magnetic head according to Technical Solution 6

[0191] The first thickness of the first magnetic layer along the first direction is thicker than the second thickness of the second magnetic layer along the first direction.

[0192] The third thickness of the third magnetic layer along the first direction is thicker than the fourth thickness of the fourth magnetic layer along the first direction.

[0193] (Technical solution 8)

[0194] The magnetic head according to Technical solution 5,

[0195] The first non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0196] The second non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0197] The third non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0198] The fourth non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0199] The fifth non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0200] (Technical solution 9)

[0201] The magnetic head according to Technical solution 8,

[0202] The first thickness of the first magnetic layer along the first direction is thicker than the second thickness of the second magnetic layer along the first direction.

[0203] The third thickness of the third magnetic layer along the first direction is thicker than the fourth thickness of the fourth magnetic layer along the first direction.

[0204] (Technical solution 10)

[0205] The magnetic head according to Technical solution 5,

[0206] The first thickness of the first magnetic layer along the first direction is thicker than the second thickness of the second magnetic layer along the first direction.

[0207] The third thickness of the third magnetic layer along the first direction is thinner than the fourth thickness of the fourth magnetic layer along the first direction.

[0208] (Technical solution 11)

[0209] The magnetic head according to Technical Solution 10

[0210] The first non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0211] The second non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0212] The third non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

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

[0214] The fifth non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0215] (Technical Solution 12)

[0216] The magnetic head according to any one of Technical Solutions 5 to 11

[0217] The first non-magnetic layer is in contact with the first magnetic pole and the first magnetic layer.

[0218] The second non-magnetic layer is in contact with the first magnetic layer and the second magnetic layer.

[0219] The third non-magnetic layer is in contact with the second magnetic layer and the third magnetic layer.

[0220] The fourth non-magnetic layer is in contact with the third magnetic layer and the fourth magnetic layer.

[0221] The fifth non-magnetic layer is in contact with the fourth magnetic layer and the second magnetic pole.

[0222] (Technical Solution 13)

[0223] The magnetic head according to Technical Solution 5

[0224] The magnetic element further includes:

[0225] A fifth magnetic layer disposed between the third non-magnetic layer and the third magnetic layer; and

[0226] A sixth non-magnetic layer disposed between the fifth magnetic layer and the third magnetic layer.

[0227] (Technical Solution 14)

[0228] The magnetic head according to Technical Solution 13

[0229] The first non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0230] The second non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0231] The third non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W,

[0232] The fourth non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag,

[0233] The fifth non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W,

[0234] The sixth non-magnetic layer contains at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0235] (Technical solution 15)

[0236] The magnetic head according to technical solution 14,

[0237] The first thickness of the first magnetic layer along the first direction is thicker than the second thickness of the second magnetic layer along the first direction,

[0238] The third thickness of the third magnetic layer along the first direction is thicker than the fourth thickness of the fourth magnetic layer along the first direction,

[0239] The fifth thickness of the fifth magnetic layer along the first direction is thinner than the third thickness.

[0240] (Technical solution 16)

[0241] The magnetic head according to any one of technical solutions 1 to 15,

[0242] Perform the first action and the second action,

[0243] In the first action, the element current supplied between the first magnetic pole and the second magnetic pole flows from the first magnetic pole to the second magnetic pole,

[0244] In the second action, the element current flows from the second magnetic pole to the first magnetic pole.

[0245] (Technical solution 17)

[0246] A magnetic recording device includes:

[0247] The magnetic head according to any one of technical solutions 1 to 15; and

[0248] An element circuit configured to supply an element current between the first magnetic pole and the second magnetic pole.

[0249] The element circuit is configured to perform a first operation and a second operation.

[0250] In the first operation, the element current flows from the first magnetic pole to the second magnetic pole.

[0251] In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

[0252] (Technical solution 18)

[0253] A magnetic recording device comprising:

[0254] A magnetic head;

[0255] A magnetic recording medium;

[0256] An element circuit; and

[0257] A control unit,

[0258] The magnetic head is configured to record information on the magnetic recording medium.

[0259] The magnetic head includes:

[0260] A first magnetic pole;

[0261] A second magnetic pole; and

[0262] A magnetic element disposed between the first magnetic pole and the second magnetic pole.

[0263] The magnetic element includes:

[0264] A first magnetic layer disposed between the first magnetic pole and the second magnetic pole;

[0265] A second magnetic layer disposed between the first magnetic layer and the second magnetic pole;

[0266] A third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and

[0267] A fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole.

[0268] The element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole.

[0269] The element circuit is configured to perform a first operation and a second operation.

[0270] In the first operation, the element current flows from the first magnetic pole to the second magnetic pole.

[0271] In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

[0272] The control unit is configured to cause the element circuit to perform the first operation when a recording position on the magnetic recording medium is closer to the inside than a determined position.

[0273] The control unit is configured to cause the element circuit to perform the second operation when the recording position on the magnetic recording medium is not closer to the inside than the determined position.

[0274] (Technical solution 19)

[0275] A magnetic recording device includes:

[0276] A magnetic head;

[0277] A magnetic recording medium;

[0278] An element circuit; and

[0279] A control unit,

[0280] The magnetic head is configured to record information on the magnetic recording medium.

[0281] The magnetic head includes:

[0282] A first magnetic pole;

[0283] A second magnetic pole; and

[0284] A magnetic element disposed between the first magnetic pole and the second magnetic pole,

[0285] The magnetic element includes:

[0286] A first magnetic layer disposed between the first magnetic pole and the second magnetic pole;

[0287] A second magnetic layer disposed between the first magnetic layer and the second magnetic pole;

[0288] A third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and

[0289] A fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole,

[0290] The element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole.

[0291] The element circuit is configured to perform a first operation and a second operation.

[0292] In the first operation, the element current flows from the first magnetic pole to the second magnetic pole.

[0293] In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

[0294] The control unit is configured to cause the element circuit to perform the first operation when the recording density in the circumferential direction is lower than a determined density.

[0295] The control unit is configured to cause the element circuit to perform the second operation when the recording density in the circumferential direction is not lower than the determined density.

[0296] (Technical solution 20)

[0297] A magnetic recording device includes:

[0298] A magnetic head;

[0299] A magnetic recording medium;

[0300] An element circuit; and

[0301] A control unit,

[0302] The magnetic head is configured to record information on the magnetic recording medium.

[0303] The magnetic head includes:

[0304] A first magnetic pole;

[0305] A second magnetic pole; and

[0306] A magnetic element disposed between the first magnetic pole and the second magnetic pole.

[0307] The magnetic element includes:

[0308] A first magnetic layer disposed between the first magnetic pole and the second magnetic pole;

[0309] A second magnetic layer disposed between the first magnetic layer and the second magnetic pole;

[0310] A third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and

[0311] A fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole.

[0312] The element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole.

[0313] The element circuit is configured to perform a first operation and a second operation.

[0314] In the first operation, the element current flows from the first magnetic pole to the second magnetic pole.

[0315] In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

[0316] The control unit is configured to cause the element circuit to perform the first operation in the case of performing the shingled write recording.

[0317] The control unit is configured to cause the element circuit to perform the second operation in the case of performing a recording other than the shingled write recording.

[0318] According to the embodiment, a magnetic recording device capable of increasing the recording density can be provided.

[0319] In the present specification, "perpendicular" and "parallel" do not merely refer to strict perpendicularity and strict parallelism, but also include, for example, deviations in the manufacturing process, etc., as long as they are substantially perpendicular and substantially parallel.

[0320] As described above, the embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific configurations of each element such as the magnetic poles, magnetic elements, magnetic layers, non-magnetic layers, and control unit included in the magnetic head and the magnetic recording device, as long as those skilled in the art can similarly implement the present invention and obtain the same effects by appropriately selecting from the known range, they are included in the scope of the present invention.

[0321] A solution obtained by combining any two or more elements of each specific example within a technically possible range is also included in the scope of the present invention as long as it includes the gist of the present invention.

[0322] In addition, all magnetic recording devices that those skilled in the art can appropriately design and modify based on the magnetic recording device described as an embodiment of the present invention and implement, as long as they include the gist of the present invention, also belong to the scope of the present invention.

[0323] Furthermore, it should be understood that within the scope of the idea of the present invention, as long as various modification examples and correction examples can be conceived by those skilled in the art, these modification examples and correction examples also belong to the scope of the present invention.

[0324] 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 modifications 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 magnetic element disposed between the first magnetic pole and the second magnetic pole in a first direction from the first magnetic pole to the second magnetic pole, The magnetic element includes: A first magnetic layer disposed between the first magnetic pole and the second magnetic pole; A second magnetic layer disposed between the first magnetic layer and the second magnetic pole; A third magnetic layer disposed between the second magnetic layer and the second magnetic pole; And A fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole, The first magnetic layer includes a first surface opposite to the first magnetic pole, The fourth magnetic layer includes a second surface opposite to the second magnetic pole, A first area of the first surface is larger than a second area of the second surface.

2. The magnetic head according to claim 1, The first magnetic pole includes a medium-facing surface, A first length of the first surface along a second direction is longer than a second length of the second surface along the second direction, The second direction is along the medium-facing surface and orthogonal to the first direction.

3. The magnetic head according to claim 2, The first surface includes a first end and a first other end, A direction from the first other end to the first end is along the second direction, The second surface includes a second end and a second other end, A direction from the second other end to the second end is along the second direction, A distance between the first end and the second end is shorter than a distance between the first end and the second other end, A first angle between a first straight line passing through the first end and the second end and a direction perpendicular to the first surface is 5 degrees or more and 15 degrees or less.

4. The magnetic head according to claim 1, The magnetic element further includes: A first non-magnetic layer disposed between the first magnetic pole and the first magnetic layer; A second non-magnetic layer disposed between the first magnetic layer and the second magnetic layer; A third non-magnetic layer disposed between the second magnetic layer and the third magnetic layer; A fourth non-magnetic layer disposed between the third magnetic layer and the fourth magnetic layer; and A fifth non-magnetic layer disposed between the fourth magnetic layer and the second magnetic pole.

5. The magnetic head according to claim 4, The magnetic element further includes: A fifth magnetic layer disposed between the third non-magnetic layer and the third magnetic layer; And A sixth non-magnetic layer disposed between the fifth magnetic layer and the third magnetic layer.

6. The magnetic head according to claim 1, Performing a first operation and a second operation, In the first operation, an element current supplied between the first magnetic pole and the second magnetic pole flows from the first magnetic pole to the second magnetic pole, In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

7. A magnetic recording device, comprising: The magnetic head according to claim 1; and An element circuit configured to supply an element current between the first magnetic pole and the second magnetic pole, The element circuit is configured to perform a first operation and a second operation, In the first operation, the element current flows from the first magnetic pole to the second magnetic pole, In the second operation, the element current flows from the second magnetic pole to the first magnetic pole.

8. A magnetic recording apparatus comprising: a magnetic head; a magnetic recording medium; an element circuit; and a control unit, wherein the magnetic head is configured to record information on the magnetic recording medium, the magnetic head includes: a first magnetic pole; a second magnetic pole; and a magnetic element disposed between the first magnetic pole and the second magnetic pole, the magnetic element includes: a first magnetic layer disposed between the first magnetic pole and the second magnetic pole; a second magnetic layer disposed between the first magnetic layer and the second magnetic pole; a third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and a fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole, the element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole, the element circuit is configured to perform a first operation and a second operation, in the first operation, the element current flows from the first magnetic pole to the second magnetic pole, in the second operation, the element current flows from the second magnetic pole to the first magnetic pole, the control unit is configured to cause the element circuit to perform the first operation when a recording position for recording on the magnetic recording medium is closer to the inside than a determined position, the control unit is configured to cause the element circuit to perform the second operation when the recording position for recording on the magnetic recording medium is not closer to the inside than the determined position.

9. A magnetic recording apparatus comprising: a magnetic head; a magnetic recording medium; an element circuit; and a control unit, wherein the magnetic head is configured to record information on the magnetic recording medium, the magnetic head includes: a first magnetic pole; a second magnetic pole; and a magnetic element disposed between the first magnetic pole and the second magnetic pole, the magnetic element includes: a first magnetic layer disposed between the first magnetic pole and the second magnetic pole; a second magnetic layer disposed between the first magnetic layer and the second magnetic pole; a third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and a fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole, the element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole, the element circuit is configured to perform a first operation and a second operation, in the first operation, the element current flows from the first magnetic pole to the second magnetic pole, in the second operation, the element current flows from the second magnetic pole to the first magnetic pole, the control unit is configured to cause the element circuit to perform the first operation when a recording density in the circumferential direction is lower than a determined density, the control unit is configured to cause the element circuit to perform the second operation when the recording density in the circumferential direction is not lower than the determined density.

10. A magnetic recording apparatus comprising: a magnetic head; a magnetic recording medium; an element circuit; and a control unit, wherein the magnetic head is configured to record information on the magnetic recording medium, the magnetic head includes: a first magnetic pole; a second magnetic pole; and A magnetic element is disposed between the first magnetic pole and the second magnetic pole. The magnetic element includes: A first magnetic layer disposed between the first magnetic pole and the second magnetic pole; A second magnetic layer disposed between the first magnetic layer and the second magnetic pole; A third magnetic layer disposed between the second magnetic layer and the second magnetic pole; and A fourth magnetic layer disposed between the third magnetic layer and the second magnetic pole. The element circuit is configured to supply an element current between the first magnetic pole and the second magnetic pole. The element circuit is configured to perform a first operation and a second operation. In the first operation, the element current flows from the first magnetic pole to the second magnetic pole. In the second operation, the element current flows from the second magnetic pole to the first magnetic pole. The control unit is configured to cause the element circuit to perform the first operation when performing shingled write recording. The control unit is configured to cause the element circuit to perform the second operation when performing a recording other than the shingled write recording.

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