Magnetic head and magnetic recording device

Abstract

The present application provides a magnetic head and a magnetic recording device capable of improving recording density. According to an embodiment, the magnetic head includes a first pole, a second pole, a laminate, and first to third terminals. The laminate is disposed between the first pole and the second pole. The laminate includes first to fourth magnetic layers and first to fifth non-magnetic layers. The first terminal is electrically connected to the first pole. The second terminal is electrically connected to the second pole. The third terminal is electrically connected to the third non-magnetic layer.

Description

[0001] This application is based on Japanese Patent Application No. 2022-024470 (Filing date: February 21, 2022) and claims priority thereto. This application incorporates by reference the entire contents of the aforementioned application. TECHNICAL FIELD

[0002] Embodiments of the present application relate to a magnetic head and a magnetic recording device. BACKGROUND

[0003] With a magnetic head, information is recorded on a magnetic recording medium such as a hard disk drive (HDD). In a magnetic head and a magnetic recording device, it is desirable to increase the recording density. SUMMARY

[0004] Embodiments of the present application provide a magnetic head and a magnetic recording device that can increase the recording density.

[0005] Means for solving the problem

[0006] According to an embodiment of the present application, a magnetic head includes a first magnetic pole, a second magnetic pole, a laminate, a first terminal, a second terminal, and a third terminal. The laminate is provided between the first magnetic pole and the second magnetic pole. The laminate includes a first magnetic layer, 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, a fourth magnetic layer provided between the third magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer, a second non-magnetic layer provided between the first magnetic layer and the second magnetic layer and in contact with the first magnetic layer and the second magnetic layer, a third non-magnetic layer provided between the second magnetic layer and the third magnetic layer, a fourth non-magnetic layer provided between the third magnetic layer and the fourth magnetic layer and in contact with the third magnetic layer and the fourth magnetic layer, and a fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole. The first terminal is electrically connected to the first magnetic pole. The second terminal is electrically connected to the second magnetic pole. The third terminal is electrically connected to the third non-magnetic layer.

[0007] According to the magnetic head configured as described above, it is possible to provide a magnetic head and a magnetic recording device that can increase the recording density. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0010] Figure 3 is a schematic plan view illustrating the magnetic head of the first embodiment.

[0011] Figure 4 is a schematic plan view illustrating the magnetic head of the first embodiment.

[0012] Figure 5 is a schematic plan view illustrating the magnetic head of the first embodiment.

[0013] Figure 6 is a schematic view illustrating the magnetic recording apparatus of the second embodiment.

[0014] Figure 7 is a schematic view illustrating the magnetic recording apparatus of the second embodiment.

[0015] Figure 8 (a) ~ Figure 8 (c) is a schematic view illustrating the operation of the magnetic head.

[0016] Figure 9 is a schematic perspective view illustrating the magnetic recording apparatus of the embodiment.

[0017] Figure 10 is a schematic perspective view illustrating a part of the magnetic recording apparatus of the embodiment.

[0018] Figure 11 is a schematic perspective view illustrating the magnetic recording apparatus of the embodiment.

[0019] Figure 12 (a) and Figure 12 (b) is a schematic perspective view illustrating a part of the magnetic recording apparatus of the embodiment.

[0020] [Label Explanation]

[0021] 20...stack, 21-26...1st-6th magnetic layers, 21M-24M...magnetization, 30F...medium facing surface, 30c...coil, 31, 32...1st and 2nd magnetic poles, 31M, 32M...magnetization, 31R, 32R...1st and 2nd resistive elements, 41-45...1st-5th non-magnetic layers, 43a, 43b...1st and 2nd partial regions, 50...control section, 51-53...1st-3rd circuits, 60...recording section, 70...reproducing section, 71...magnetic reproducing element, 72a...1st reproducing magnetic shield, 72b...2nd reproducing magnetic shield, 80...magnetic recording medium, 81...magnetic recording layer, 82...medium substrate, 83...magnetization, 85...medium moving direction, 110-114...magnetic head, 150...magnetic recording device, 154...suspension, 155...arm, 156...voice coil motor, 157...bearing section, 158...head gimbal assembly, 159...head slider, 159A...air inflow side, 159B...air outflow side, 160...head stack assembly, 161...holder, 162...coil, 180...recording medium disk, 180M...spindle motor, 181...recording medium, 190...signal processing section, 210-212...magnetic recording device, AR...arrow, D1...direction, F1-F4...1st-4th surfaces, Iw...recording current, L1-L3, Lz1-Lz3...length, T1-T3...1st-3rd terminals, W1-W3...1st-3rd wiring lines, cpl, cp2...1st and 2nd current paths, il, i2...1st and 2nd currents, tl-t4...1st-4th thicknesses, t41-t45...thicknesses DETAILED DESCRIPTION

[0022] Hereinafter, each embodiment of the present application will be described with reference to the drawings.

[0023] The drawings are schematic or conceptual, and the relationship between the thickness and width of each portion, the ratio of sizes between portions, and the like are not necessarily the same as actual ones. Even in cases where the same portions are represented, the dimensions and ratios of each other can sometimes appear different depending on the drawings.

[0024] In the present application specification and each drawing, the same elements as those explained in the already-explained drawings are given the same reference numerals and a detailed explanation is appropriately omitted.

[0025] (1st Embodiment)

[0026] Figure 1 is a schematic plan view illustrating a magnetic head of the 1st embodiment.

[0027] Figure 2 is a schematic cross-sectional view illustrating the magnetic head of the 1st embodiment.

[0028] As Figure 1 andFigure 2 As shown, the magnetic head 110 of the embodiment includes a first magnetic pole 31, a second magnetic pole 32, a laminate 20, a first wiring W1, a second wiring W2 and a third wiring W3.

[0029] The laminate 20 is disposed between the first magnetic pole 31 and the second magnetic pole 32. 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. 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.

[0030] A first non-magnetic layer 41 is disposed between the first magnetic pole 31 and the first magnetic layer 21. A second non-magnetic layer 42 is disposed between the first magnetic layer 21 and the second magnetic layer 22, and is in contact with both the first magnetic layer 21 and the second magnetic layer 22. A third non-magnetic layer 43 is disposed between the second magnetic layer 22 and the third magnetic layer 23. A fourth non-magnetic layer 44 is disposed between the third magnetic layer 23 and the fourth magnetic layer 24, and is in contact with both the third magnetic layer 23 and the fourth magnetic layer 24. A fifth non-magnetic layer 45 is disposed between the fourth magnetic layer 24 and the second magnetic pole 32.

[0031] Terminal T1 is electrically connected to the first magnetic pole 31. In this example, terminal T1 is electrically connected to the first magnetic pole 31 via the first wiring W1. Terminal T2 is electrically connected to the second magnetic pole 32. In this example, terminal T2 is electrically connected to the second magnetic pole 32 via the second wiring W2. Terminal T3 is electrically connected to the third non-magnetic layer 43. In this example, terminal T3 is electrically connected to the third non-magnetic layer 43 via the third wiring W3.

[0032] like Figure 2 As shown, the magnetic head 110 may include a coil 30c. The coil 30c is oriented opposite to at least a portion of the first magnetic pole 31. The magnetic recording apparatus 210 of the embodiment includes, for example, a magnetic head 110, a control unit 50, and a magnetic recording medium 80. The control unit 50 may include a third circuit 53. The third circuit 53 can supply a recording current Iw to the coil 30c. For example, a recording magnetic field corresponding to the recording current Iw is generated from the first magnetic pole 31. The recording magnetic field is applied to the magnetic recording medium 80. Information is recorded by changing the magnetization of the magnetic recording medium 80.

[0033] The first magnetic pole 31, the second magnetic pole 32, and the stack 20 are included in the recording section 60. As will be described later, a playback section may also be provided in the magnetic head 110.

[0034] The first magnetic pole 31 is, for example, a main magnetic pole. The first magnetic pole 31 includes a medium facing surface 30F. The medium facing surface 30F is along an ABS (Air Bearing Surface) of the magnetic head 110. The medium facing surface 30F faces the magnetic recording medium 80.

[0035] A direction perpendicular to the medium facing surface 30F is taken as a Z-axis direction. One direction perpendicular to the Z-axis direction is taken as an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is taken as a Y-axis direction.

[0036] The Z-axis direction is, for example, a height direction. The X-axis direction is, for example, a down-track direction. The Y-axis direction is a cross-track direction.

[0037] The second magnetic pole 32 corresponds, for example, to a "trailing shield". The second magnetic pole 32 is, for example, an auxiliary magnetic pole. The second magnetic pole 32 can form a magnetic core together with the first magnetic pole 31. An additional shield such as a side shield (not shown) can also be provided.

[0038] As shown in FIG. 1, the first magnetic pole 31 is provided on the first magnetic layer 21. As shown in FIG. 1, the second magnetic pole 32 is provided on the fourth magnetic layer 24. Figure 1 and Figure 2 A direction from the first magnetic layer 21 to the fourth magnetic layer 24 is taken as a first direction Dl. As shown in FIG. 1, the first direction Dl is along the X-axis direction. An angle between the first direction Dl and the X-axis direction is smaller than an angle between the first direction Dl and the Z-axis direction and smaller than an angle between the first direction Dl and the Y-axis direction. The first direction Dl can also be inclined with respect to the X-axis direction. Figure 2 As shown in FIG. 1, the first current il and the second current i2 can flow through the laminated body 20. The first current il is a current from the first magnetic pole 31 to the third non-magnetic layer 43. The second current i2 is a current from the second magnetic pole 32 to the third non-magnetic layer 43. These currents are supplied from the control section 50. The first current il flows in a direction from the first terminal Tl to the third terminal T3. The second current i2 flows in a direction from the second terminal T2 to the third terminal T3. Electrons corresponding to the first current il flow from the third non-magnetic layer 43 toward the first magnetic pole 31. Electrons corresponding to the second current i2 flow from the third non-magnetic layer 43 toward the second magnetic pole 32.

[0039] Figure 1 As shown in FIG. 1, the first current il and the second current i2 can flow through the laminated body 20. The first current il is a current from the first magnetic pole 31 to the third non-magnetic layer 43. The second current i2 is a current from the second magnetic pole 32 to the third non-magnetic layer 43. These currents are supplied from the control section 50. The first current il flows in a direction from the first terminal Tl to the third terminal T3. The second current i2 flows in a direction from the second terminal T2 to the third terminal T3. Electrons corresponding to the first current il flow from the third non-magnetic layer 43 toward the first magnetic pole 31. Electrons corresponding to the second current i2 flow from the third non-magnetic layer 43 toward the second magnetic pole 32.

[0040] ​An alternating magnetic field (e.g., a high-frequency magnetic field) is generated from the laminate 20 by the first current i1 and the second current i2. The alternating magnetic field generated from the laminate 20 is applied to the magnetic recording medium 80, and assists writing to the magnetic recording medium 80. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented. The frequency of the alternating magnetic field is, for example, 10 GHz or more and 50 GHz or less. The frequency of the alternating magnetic field is, for example, desirably 20 GHz or more and 40 GHz or less.

[0041] The alternating magnetic field is, for example, based on oscillation of magnetization of the magnetic layers included in the laminate 20. In the embodiment, high oscillation efficiency is obtained. More efficient MAMR can be implemented. According to the embodiment, a magnetic head that can improve recording density can be provided.

[0042] Figure 3 is a schematic plan view illustrating the magnetic head of the first embodiment.

[0043] Figure 3 An example of magnetization when the above-described first current i1 and second current i2 flow is shown. As shown in Figure 3 the direction of the magnetization 32M of the second magnetic pole 32 and the direction of the magnetization 31M of the first magnetic pole 31 are the same. At this time, the magnetization 22M of the second magnetic layer 22 and the magnetization 23M of the third magnetic layer 23 are reversed with respect to the magnetization 31M. The magnetization 21M of the first magnetic layer 21 and the magnetization 24M of the fourth magnetic layer 24 oscillate. With the oscillation, an alternating magnetic field is generated.

[0044] For example, the first magnetic layer 21 and the fourth magnetic layer 24 function as FGLs (Field Generation Layers). For example, the second magnetic layer 22 and the third magnetic layer 23 function as SILs (Spin Injection Layers).

[0045] In the embodiment, the spin torque from the first magnetic pole 31 and the spin torque from the second magnetic pole 32 can be utilized. Thereby, in the first magnetic layer 21 and the fourth magnetic layer 24, oscillation is efficiently generated.

[0046] In the embodiment, the direction of the magnetization 22M of the second magnetic layer 22 and the direction of the magnetization 23M of the third magnetic layer 23 are the same. Thereby, these magnetizations are easily stabilized.

[0047] As described above, the magnetizations 22M of the second magnetic layer 22 and 23M of the third magnetic layer 23 are opposite to the magnetization 31M. Therefore, the recording magnetic field emanating from the first magnetic pole 31 is difficult to penetrate within the laminate 20. Consequently, the recording magnetic field can be applied to the magnetic recording medium more efficiently, enabling more efficient recording.

[0048] like Figure 1 As shown, in this example, the first non-magnetic layer 41 is connected to the first magnetic pole 31 and the first magnetic layer 21. The fifth non-magnetic layer 45 is connected to the fourth magnetic layer 24 and the second magnetic pole 32. As will be described later, other non-magnetic layers may also be provided between the first magnetic pole 31 and the first magnetic layer 21. As will be described later, other non-magnetic layers may also be provided between the fourth magnetic layer 24 and the second magnetic pole 32.

[0049] like Figure 1 As shown, the thickness of the first magnetic layer 21 along the first direction D1 (from the first magnetic layer 21 to the fourth magnetic layer 24) is defined as the first thickness t1. The thickness of the second magnetic layer 22 along the first direction D1 is defined as the second thickness t2. The thickness of the third magnetic layer 23 along the first direction D1 is defined as the third thickness t3. The thickness of the fourth magnetic layer 24 along the first direction D1 is defined as the fourth thickness t4.

[0050] In this embodiment, the first thickness t1 is preferably thicker than the second thickness t2 and the third thickness t3. The fourth thickness t4 is preferably thicker than the second thickness t2 and the third thickness t3. With this thickness relationship, the magnetization of the first magnetic layer 21 and the fourth magnetic layer 24 can oscillate more efficiently. With this thickness relationship, the magnetization of the second magnetic layer 22 and the third magnetic layer 23 can be reversed more effectively.

[0051] For example, the first thickness t1 is preferably more than 1.1 times the second thickness t2 and more than 1.1 times the third thickness t3. For example, the fourth thickness t4 is preferably more than 1.1 times the second thickness t2 and more than 1.1 times the third thickness t3.

[0052] For example, the first thickness t1 is preferably 5 nm or more and 15 nm or less. The second thickness t2 is preferably 1 nm or more and less than 5 nm. The third thickness t3 is preferably 1 nm or more and less than 5 nm. The fourth thickness t4 is preferably 5 nm or more and 15 nm or less. By making the first thickness t1 and the fourth thickness t4 5 nm or more, efficient oscillation is easily obtained. By making the first thickness t1 and the fourth thickness t4 15 nm or less, it is possible to suppress the thickness of the laminate 20 from becoming too thick. By making the second thickness t2 and the third thickness t3 less than 5 nm, efficient magnetization reversal is easily obtained. By making the second thickness t2 and the third thickness t3 1 nm or more, efficient oscillation is easily obtained.

[0053] The first magnetic layer 21, the second magnetic layer 22, the third magnetic layer 23, and the fourth magnetic layer 24 include, for example, at least one selected from the group consisting of Fe, Co, and Ni.

[0054] For example, at least any one of the first nonmagnetic layer 41, the second nonmagnetic layer 42, the fourth nonmagnetic layer 44, and the fifth nonmagnetic layer 45 includes at least one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag. For example, spin can be efficiently transmitted.

[0055] For example, the third nonmagnetic layer 43 includes at least one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. Thereby, for example, the spin interaction between the second magnetic layer 22 and the third magnetic layer 23 becomes small. For example, it is easy to stably oscillate.

[0056] The thickness t41 of the first nonmagnetic layer 41 along the first direction D1 is preferably 0.5 nm or more and 5 nm or less. The thickness t42 of the second nonmagnetic layer 42 along the first direction D1 is preferably 0.5 nm or more and 5 nm or less. The thickness t43 of the third nonmagnetic layer 43 along the first direction D1 is preferably 3 nm or more and 15 nm or less. The thickness t44 of the fourth nonmagnetic layer 44 along the first direction D1 is preferably 0.5 nm or more and 5 nm or less. The thickness t45 of the fifth nonmagnetic layer 45 along the first direction D1 is preferably 0.5 nm or more and 5 nm or less.

[0057] As shown in FIG. 3, the size of the third nonmagnetic layer 43 can be larger than the size of the magnetic layer. For example, the third nonmagnetic layer 43 includes a first partial region 43a and a second partial region 43b. The first partial region 43a overlaps the second magnetic layer 22 in a direction opposite to the direction from the third nonmagnetic layer 43 to the second magnetic layer 22 (for example, a direction along the first direction D1). The second partial region 43b does not overlap the second magnetic layer 22 in the opposite direction. The first partial region 43a overlaps the fourth magnetic layer 24 in a direction opposite to the direction from the third nonmagnetic layer 43 to the fourth magnetic layer 24 (for example, a direction along the first direction D1). The second partial region 43b does not overlap the fourth magnetic layer 24 in the opposite direction. Figure 3 As shown in FIG. 3, the third nonmagnetic layer 43 includes a first face F1 opposite to the second magnetic layer 22. The second magnetic layer 22 includes a second face F2 opposite to the third nonmagnetic layer 43. The area of the first face F1 can be larger than the area of the second face F2.

[0058] Figure 3 As shown in FIG. 3, the third nonmagnetic layer 43 includes a first face F1 opposite to the second magnetic layer 22. The second magnetic layer 22 includes a second face F2 opposite to the third nonmagnetic layer 43. The area of the first face F1 can be larger than the area of the second face F2.

[0059] As shown in FIG. 3, the third nonmagnetic layer 43 includes a first face F1 opposite to the second magnetic layer 22. The second magnetic layer 22 includes a second face F2 opposite to the third nonmagnetic layer 43. The area of the first face F1 can be larger than the area of the second face F2. Figure 3 ​As shown, the third non-magnetic layer 43 includes a third surface F3 opposite to the third magnetic layer 23. The third magnetic layer 23 includes a fourth surface F4 opposite to the third non-magnetic layer 43. The area of ​​the third surface F3 is larger than the area of ​​the fourth surface F4.

[0060] like Figure 3 As shown, the length L1 is defined as the length of the third non-magnetic layer 43 along the intersection direction that intersects the direction opposite to the direction from the third non-magnetic layer 43 to the fourth magnetic layer 24 (e.g., along the direction of the first direction D1). Figure 3 In this diagram, the intersection direction is the Y-axis direction. The length of the second magnetic layer 22 along the intersection direction (Y-axis direction) is taken as length L2. The length of the third magnetic layer 23 along the intersection direction (Y-axis direction) is taken as length L3. Length L1 is longer than length L2, and longer than length L3.

[0061] In this way, the size of the third non-magnetic layer 43 can be larger than the size of the second magnetic layer 22 and the size of the third magnetic layer 23. This, for example, can reduce the current density flowing through the third non-magnetic layer 43. For example, it facilitates stable operation.

[0062] like Figure 2 As shown, the length of the third non-magnetic layer 43 along the intersection direction that intersects the opposite direction from the third non-magnetic layer 43 to the fourth magnetic layer 24 (e.g., along the direction of the first direction D1) is taken as the length Lz1. Figure 2 In this configuration, the intersection direction is perpendicular to the first direction D1. The length of the second magnetic layer 22 along this intersection direction is taken as length Lz2. The length of the third magnetic layer 23 along this intersection direction is taken as length Lz3. Length Lz1 can be longer than length Lz2 and longer than length Lz3.

[0063] The following describes several examples of the magnetic head used in the implementation.

[0064] Figure 4 This is a schematic plan view illustrating the magnetic head of the first embodiment.

[0065] like Figure 4 As shown, in the magnetic head 111 of the embodiment, the laminate 20 further includes a fifth magnetic layer 25. The fifth magnetic layer 25 is disposed between the first magnetic pole 31 and the first non-magnetic layer 41. The other than that, the configuration of the magnetic head 111 can be the same as that of the magnetic head 110.

[0066] The fifth magnetic layer 25 includes, for example, at least one element selected from the group consisting of Fe, Co, and Ni. By providing the fifth magnetic layer 25, high spin injection efficiency can be easily obtained, for example. This facilitates oscillation. The fifth magnetic layer 25 can also be considered as part of the first magnetic pole 31.

[0067] Figure 5 is a schematic plan view illustrating the magnetic head of Embodiment 1.

[0068] As shown in FIG. 1, in the magnetic head 112 of the embodiment, the laminate 20 further includes a 6th magnetic layer 26. The 6th magnetic layer 26 is provided between the 5th non-magnetic layer 45 and the 2nd magnetic pole 32. The configuration of the magnetic head 112 other than this can be the same as that of the magnetic head 110. Figure 5

[0069] The 6th magnetic layer 26 includes, for example, at least one selected from the group consisting of Fe, Co, and Ni. By providing the 6th magnetic layer 26, it is easy to obtain a high spin injection efficiency, for example. Thereby, it is easy to oscillate. The 6th magnetic layer 26 can also be regarded as a part of the 2nd magnetic pole 32. In the embodiment, both the 5th magnetic layer 25 and the 6th magnetic layer 26 can be provided.

[0070] In the embodiment, at least one of the plurality of magnetic layers (e.g., the 1st to 6th magnetic layers 21 to 26, etc.) included in the laminate 20 can include a film of a uniform composition. In the embodiment, at least one of the plurality of magnetic layers (e.g., the 1st to 6th magnetic layers 21 to 26, etc.) included in the laminate 20 can include a laminated film. In the laminated film, for example, a film including a 1st element and a film including a 2nd element are alternately laminated along the 1st direction D1. The 1st element includes, for example, one selected from the group consisting of Fe, Co, and Ni. The 2nd element includes, for example, another selected from the group consisting of Fe, Co, and Ni.

[0071] In the embodiment, at least one of the plurality of non-magnetic layers (e.g., the 1st to 5th non-magnetic layers 41 to 45, etc.) included in the laminate 20 can include a film of a uniform composition. In the embodiment, at least one of the plurality of non-magnetic layers (e.g., the 1st to 5th non-magnetic layers 41 to 45, etc.) included in the laminate 20 can include a laminated film.

[0072] In the laminated film in the 1st non-magnetic layer 41, the 2nd non-magnetic layer 42, the 4th non-magnetic layer 44, and the 5th non-magnetic layer 45, for example, a film including a 3rd element and a film including a 4th element are alternately laminated along the 1st direction D1. The 3rd element includes, for example, one selected from the group consisting of Cu, Au, Cr, Al, V, and Ag. The 4th element includes, for example, another selected from the group consisting of Cu, Au, Cr, Al, V, and Ag.

[0073] ​In the layered film in the third non-magnetic layer 43, for example, a film including a fifth element and a film including a sixth element are alternately layered along the first direction D1. The fifth element includes, for example, one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. The sixth element includes, for example, another one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.

[0074] (Second Embodiment)

[0075] The second embodiment relates to a magnetic recording device. As Figure 1 explained above, the magnetic recording device 210 of the embodiment includes the magnetic head (e.g., the magnetic head 110, etc.) of the first embodiment and the control section 50. The control section 50 is electrically connected to the first terminal T1, the second terminal T2, and the third terminal T3. As explained above, the control section 50 can supply the magnetic head (the magnetic head 110) with the first current il from the first terminal T1 to the third terminal T3 and the second current i2 from the second terminal T2 to the third terminal T3.

[0076] Figure 6 is a schematic view illustrating the magnetic recording device of the second embodiment.

[0077] As Figure 6 explained above, in the magnetic recording device 211 of the embodiment, the control section 50 includes the first circuit 51. The first circuit 51 can supply the magnetic head (e.g., the magnetic head 110) with the first current il and the second current i2. The first circuit 51 can include, for example, a current supply circuit. The first circuit 51 can also include a voltage generation circuit.

[0078] In this example, the control section 50 includes a resistance element. The resistance element includes, for example, at least either one of the first resistance element 31R and the second resistance element 32R. For example, the first resistance element 31R is provided to the first current path cpl between the first circuit 51 and the first terminal T1. The first resistance element 31R can be provided in series or in parallel. For example, the second resistance element 32R is provided to the second current path cp2 between the first circuit 51 and the second terminal T2. The second resistance element 32R can be provided in series or in parallel.

[0079] By these resistances, the first current il and the second current i2 can be adjusted. The resistance element can be provided to at least either one of the first current path cpl between the first circuit 51 and the first terminal T1 and the second current path cp2 between the first circuit 51 and the second terminal T2.

[0080] Figure 7 is a schematic view illustrating the magnetic recording device of the second embodiment.

[0081] AsFigure 7 As shown in the magnetic recording apparatus 212 of the embodiment, the control section 50 includes a first circuit 51 and a second circuit 52. The first circuit 51 is capable of supplying a first current il to the magnetic head (e.g., the magnetic head 110). The second circuit 52 is capable of supplying a second current i2 to the magnetic head (e.g., the magnetic head 110). By the two circuits, the current can be arbitrarily adjusted.

[0082] The configurations of the first circuit 51, the second circuit 52, the first resistive element 31R, and the second resistive element 32R can be applied to any magnetic head of the first embodiment.

[0083] Figure 8 (a) ~ Figure 8 (c) is a schematic diagram illustrating the operation of the magnetic head.

[0084] Figure 8 (a) corresponds to the first state ST1. In the first state ST1, substantially no first current il and second current i2 flow. Alternatively, the first current il and the second current i2 are smaller than the first threshold value. Figure 8 (b) corresponds to the second state ST2. In the second state ST2, the first current il and the second current i2 are substantially equal to or larger than the first threshold value and smaller than the second threshold value. Figure 8 (c) corresponds to the third state ST3. In the third state ST3, the first current il and the second current i2 are equal to or larger than the second threshold value.

[0085] As Figure 8 (a) shows, in the first state ST1, the directions of the magnetizations (magnetizations 21M to 24M) of the magnetic layers are the directions of the magnetization 31M of the first magnetic pole 31 and the magnetization 32M of the second magnetic pole 32. As Figure 8 (b) shows, in the second state ST2, the magnetization 22M of the second magnetic layer 22 and the magnetization 23M of the third magnetic layer 23 are reversed. As Figure 9 (c) shows, in the third state ST3, the magnetization 21M of the first magnetic layer 21 and the magnetization 24M of the fourth magnetic layer 24 are oscillated.

[0086] By making the second thickness t2 and the third thickness t3 thin, the magnetization 22M and the magnetization 23M are efficiently reversed. Thereby, the threshold value of the oscillation can be reduced. By making the first thickness t1 and the fourth thickness t4 thick, efficient oscillation is easily obtained.

[0087] Hereinafter, an example of the magnetic head and the magnetic recording medium 80 included in the magnetic recording apparatus 210 of the embodiment will be described.

[0088] Figure 9 is a schematic perspective view illustrating the magnetic recording apparatus of the embodiment.

[0089] AsFigure 9 As shown, the magnetic head (e.g., the magnetic head 110) of the embodiment is used with the magnetic recording medium 80. In this example, the magnetic head 110 includes a recording portion 60 and a reproducing portion 70. Information is recorded to the magnetic recording medium 80 by the recording portion 60 of the magnetic head 110. Information recorded to the magnetic recording medium 80 is reproduced by the reproducing portion 70.

[0090] 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 portion 60.

[0091] The reproducing portion 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 is capable of outputting a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0092] As shown, the magnetic recording medium 80 is relatively moved in the direction of the medium moving direction 85 with respect to the magnetic head 110. 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. Figure 10

[0093] Figure 10 is a schematic perspective view illustrating a part of the magnetic recording apparatus of the embodiment.

[0094] Figure 11 A head slider is illustrated.

[0095] The magnetic head 110 is provided to the head slider 159. The head slider 159 includes, for example, Al203 / TiC or the like. The head slider 159 is relatively moved with respect to the magnetic recording medium while floating or contacting on the magnetic recording medium.

[0096] The head slider 159 has, for example, an air inflow side 159A and an air outflow side 159B. The magnetic head 110 is disposed to the side surface or the like of the air outflow side 159B of the head slider 159. Thus, the magnetic head 110 is relatively moved with respect to the magnetic recording medium while floating or contacting on the magnetic recording medium.

[0097] Figure 11 is a schematic perspective view illustrating a part of the magnetic recording apparatus of the embodiment.

[0098] As shown, the magnetic recording medium 80 is relatively moved in the direction of the medium moving direction 85 with respect to the magnetic head 110. 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. Figure 12 ​As shown, in the magnetic recording apparatus 150 of the embodiment, a rotary actuator is employed. A recording medium disk 180 is mounted to a spindle motor 180M. The recording medium disk 180 is rotated by the spindle motor 180M in the direction of an arrow AR. The spindle motor 180M is responsive to a control signal from a drive apparatus control section. The magnetic recording apparatus 150 of the embodiment can have a plurality of recording medium disks 180. The magnetic recording apparatus 150 can include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). The recording medium 181 employs, for example, a nonvolatile memory such as a flash memory. The magnetic recording apparatus 150 can be, for example, a hybrid HDD (Hard Disk Drive).

[0099] The head slider 159 performs recording and reproduction of information recorded to the recording medium disk 180. The head slider 159 is provided at the top end of the thin film-like suspension 154. The magnetic head of the embodiment is provided near the top end of the head slider 159.

[0100] If the recording medium disk 180 is rotated, the pressing force generated by the suspension 154 and the pressure generated at the medium opposing surface (ABS) of the head slider 159 are balanced. The distance between the medium opposing surface of the head slider 159 and the surface of the recording medium disk 180 becomes a predetermined flying height. In the embodiment, the head slider 159 can also be in contact with the recording medium disk 180. A contact traveling type can be employed, for example.

[0101] The suspension 154 is connected to one end of an arm 155 (e.g., an actuator arm). The arm 155 has, for example, a coil holder portion and the like. The coil holder portion holds a driving coil. A voice coil motor 156 is provided at the other end of the arm 155. The voice coil motor 156 is one type of linear motor. The voice coil motor 156 includes, for example, a driving coil and a magnetic circuit. The driving coil is wound around the coil holder portion of the arm 155. The magnetic circuit includes a permanent magnet and an opposing yoke. The driving coil is provided between the permanent magnet and the opposing yoke. The suspension 154 has one end and the other end. The magnetic head is provided at the one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0102] The arm 155 is held by a ball bearing. The ball bearing is provided at two portions, upper and lower, of a bearing portion 157. The arm 155 is rotatable and slidable by the voice coil motor 156. The magnetic head is movable to an arbitrary position of the recording medium disk 180.

[0103] Figure 12 (a) and Figure 12 (b) is a schematic perspective view illustrating a portion of the magnetic recording apparatus of the embodiment.

[0104] Figure 12 (a) illustrates a portion of the magnetic recording apparatus, which is an enlarged perspective view of the head stack assembly 160.Figure 12 (b) is a perspective view illustrating a head assembly (head gimbal assembly: HGA) 158 that is a part of the head stack assembly 160.

[0105] As shown in Figure 12 (a), the head stack assembly 160 includes a bearing portion 157, the head gimbal assembly 158, and a support 161. The head gimbal assembly 158 extends from the bearing portion 157. The support 161 extends from the bearing portion 157. The support 161 extends in a direction opposite to the direction in which the head gimbal assembly 158 extends. The support 161 supports a coil 162 of the voice coil motor 156.

[0106] As 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.

[0107] A head slider 159 is provided at a top end of the suspension 154. The head slider 159 is provided with the head of the embodiment.

[0108] The head assembly (head gimbal assembly) 158 of the embodiment includes the head of the embodiment, the head slider 159 provided with the head, the suspension 154, and the 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.

[0109] The suspension 154 has, for example, a lead wire (not shown) for signal recording and reproduction. The suspension 154 can have, for example, a lead wire (not shown) for a heater for upthrust adjustment. The suspension 154 can also have, for example, a lead wire (not shown) for a spin transfer oscillator, etc. These lead wires and a plurality of electrodes provided at the head are electrically connected.

[0110] In the magnetic recording apparatus 150, a signal processing portion 190 is provided. The signal processing portion 190 performs signal recording and reproduction to the magnetic recording medium using the head. The input and output lines of the signal processing portion 190 are connected to electrode pads of the head gimbal assembly 158, for example, and are electrically connected to the head.

[0111] The magnetic recording apparatus 150 of the embodiment includes a magnetic recording medium, a head of the embodiment, a movable portion, a position control portion, and a signal processing portion. The movable portion is relatively movable in a state in which the magnetic recording medium and the head are separated or in contact with each other. The position control portion causes the head to be positioned at a predetermined recording position on the magnetic recording medium. The signal processing portion performs signal recording and reproduction to the magnetic recording medium using the head.

[0112] For example, as the magnetic recording medium described above, a recording medium disk 180 is used. The movable portion described above includes, for example, the head slider 159. The position control portion described above includes, for example, the head gimbal assembly 158.

[0113] Embodiments can include the following configurations (e.g., technical solutions).

[0114] (Construction 1)

[0115] A magnetic head has:

[0116] a first magnetic pole;

[0117] a second magnetic pole;

[0118] a laminate provided between the first magnetic pole and the second magnetic pole, the laminate including a first magnetic layer, 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, a fourth magnetic layer provided between the third magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer, a second non-magnetic layer provided between the first magnetic layer and the second magnetic layer and in contact with the first magnetic layer and the second magnetic layer, a third non-magnetic layer provided between the second magnetic layer and the third magnetic layer, a fourth non-magnetic layer provided between the third magnetic layer and the fourth magnetic layer and in contact with the third magnetic layer and the fourth magnetic layer, and a fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole;

[0119] a first terminal electrically connected to the first magnetic pole;

[0120] a second terminal electrically connected to the second magnetic pole; and

[0121] a third terminal electrically connected to the third non-magnetic layer.

[0122] (Construction 2)

[0123] The magnetic head according to Construction 1, wherein

[0124] the first non-magnetic layer is in contact with the first magnetic pole and the first magnetic layer;

[0125] the fifth non-magnetic layer is in contact with the fourth magnetic layer and the second magnetic pole.

[0126] (Construction 3)

[0127] The magnetic head according to Construction 1, wherein

[0128] the laminate further includes a fifth magnetic layer provided between the first magnetic pole and the first non-magnetic layer.

[0129] (Construction 4)

[0130] The magnetic head according to Construction 3, wherein

[0131] The fifth magnetic layer is in contact with the first magnetic pole.

[0132] (Constitution 5)

[0133] The magnetic head according to any one of Constitutions 1 to 3, wherein

[0134] The laminate further includes a sixth magnetic layer provided between the fifth non-magnetic layer and the second magnetic pole.

[0135] (Constitution 6)

[0136] The magnetic head according to any one of Constitutions 1 to 5, wherein

[0137] A first thickness of the first magnetic layer in a first direction from the first magnetic layer toward the fourth magnetic layer is thicker than a second thickness of the second magnetic layer in the first direction and thicker than a third thickness of the third magnetic layer in the first direction;

[0138] A fourth thickness of the fourth magnetic layer in the first direction is thicker than the second thickness and thicker than the third thickness.

[0139] (Constitution 7)

[0140] The magnetic head according to Constitution 6, wherein

[0141] The first thickness is 1.1 times or more of the second thickness and 1.1 times or more of the third thickness;

[0142] The fourth thickness is 1.1 times or more of the second thickness and 1.1 times or more of the third thickness.

[0143] (Constitution 8)

[0144] The magnetic head according to any one of Constitutions 6 to 7, wherein

[0145] The first thickness is 5 nm or more and 15 nm or less;

[0146] The second thickness is 1 nm or more and less than 5 nm;

[0147] The third thickness is 1 nm or more and less than 5 nm;

[0148] The fourth thickness is 5 nm or more and 15 nm or less.

[0149] (Constitution 9)

[0150] The magnetic head according to any one of Constitutions 1 to 8, wherein

[0151] At least any one of the first non-magnetic layer, the second non-magnetic layer, the fourth non-magnetic layer, and the fifth non-magnetic layer includes at least one selected from a group consisting of Cu, Au, Cr, Al, V, and Ag.

[0152] (Structure 10)

[0153] The magnetic head according to any one of structures 1 to 9, wherein

[0154] The third non-magnetic layer includes at least one selected from a group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.

[0155] (Structure 11)

[0156] The magnetic head according to any one of structures 1 to 10, wherein

[0157] The third non-magnetic layer includes a first surface facing the second magnetic layer;

[0158] The second magnetic layer includes a second surface facing the third non-magnetic layer;

[0159] An area of the first surface is larger than an area of the second surface.

[0160] (Structure 12)

[0161] The magnetic head according to any one of structures 1 to 11, wherein

[0162] The third non-magnetic layer includes a third surface facing the third magnetic layer;

[0163] The third magnetic layer includes a fourth surface facing the third non-magnetic layer;

[0164] An area of the third surface is larger than an area of the fourth surface.

[0165] (Structure 13)

[0166] The magnetic head according to any one of structures 1 to 10, wherein

[0167] The third non-magnetic layer includes a first partial region and a second partial region;

[0168] The first partial region overlaps the second magnetic layer in a facing direction from the third non-magnetic layer to the second magnetic layer;

[0169] The second partial region does not overlap the second magnetic layer in the facing direction.

[0170] (Structure 14)

[0171] The magnetic head according to any one of aspects 1 to 10, wherein

[0172] The third non-magnetic layer includes a first partial region and a second partial region;

[0173] The first partial region overlaps the fourth magnetic layer in an opposite direction from the third non-magnetic layer to the fourth magnetic layer;

[0174] The second partial region does not overlap the fourth magnetic layer in the opposite direction.

[0175] (Aspect 15)

[0176] The magnetic head according to any one of aspects 1 to 10, wherein

[0177] A length of the third non-magnetic layer along a crossing direction intersecting an opposite direction from the third non-magnetic layer to the fourth magnetic layer is longer than a length of the second magnetic layer along the crossing direction and longer than a length of the third magnetic layer along the crossing direction.

[0178] (Aspect 16)

[0179] A magnetic recording apparatus having the magnetic head according to any one of aspects 1 to 15 and a control portion electrically connected to the first terminal, the second terminal, and the third terminal;

[0180] The control portion is capable of supplying a first current from the first terminal to the third terminal and a second current from the second terminal to the third terminal to the magnetic head.

[0181] (Aspect 17)

[0182] The magnetic recording apparatus according to aspect 16, wherein

[0183] The control portion includes a first circuit and a resistance element

[0184] The first circuit is capable of supplying the first current and the second current to the magnetic head;

[0185] The resistance element is provided at least one of a first current path between the first circuit and the first terminal and a second current path between the first circuit and the second terminal.

[0186] (Aspect 18)

[0187] The magnetic recording apparatus according to aspect 16, wherein

[0188] The control portion includes a first circuit and a second circuit;

[0189] The first circuit supplies the first current to the magnetic head.

[0190] The second circuit supplies the second current to the magnetic head.

[0191] (Construction 19)

[0192] The magnetic recording apparatus according to any one of constructions 16 to 18, wherein

[0193] Further comprising a third circuit;

[0194] The magnetic head further comprises a coil;

[0195] The third circuit supplies a recording current to the coil.

[0196] (Construction 20)

[0197] The magnetic recording apparatus according to any one of constructions 16 to 19, wherein

[0198] An alternating magnetic field is generated from the layered body in accordance with the first current and the second current.

[0199] According to the embodiments, a magnetic head and a magnetic recording apparatus capable of improving recording density can be provided.

[0200] In the present specification, "perpendicular" and "parallel" are not strict perpendicular and strict parallel, and include, for example, a deviation in a manufacturing process, and the like, as long as they are substantially perpendicular and substantially parallel.

[0201] The embodiments of the present application have been described above with reference to specific examples. However, the present application is not limited to these specific examples. For example, as to the specific construction of each element such as a magnetic pole, a magnetic layer, a non-magnetic layer, a terminal, and a control section included in the magnetic head and the magnetic recording apparatus, as long as the same effects as those of the present application can be obtained by appropriately selecting from a known range, it is also included in the scope of the present application.

[0202] Further, a construction in which two or more elements of any of the specific examples are combined within a technically possible range is also included in the scope of the present application as long as the gist of the present application is included.

[0203] Furthermore, as the embodiments of the present application, all of the magnetic heads and the magnetic recording apparatuses which can be implemented by a person skilled in the art by appropriately designing changes based on the above-described magnetic head and the magnetic recording apparatus also belong to the scope of the present application as long as the gist of the present application is included.

[0204] Further, it should be understood that various modifications and changes can be made within the scope of the idea of the present application, and such modifications and changes also belong to the scope of the present application.

[0205] The present application has been described with several embodiments, but these embodiments are presented as examples and are not intended to limit the scope of the application. These new embodiments can be implemented in various other ways, and various omissions, substitutions, changes can be made within the scope of the gist of the application. These embodiments and variations thereof are included in the scope, gist of the application, and are included in the scope of the application and equivalents thereof as recited in the claims.

Claims

1. A magnetic head, comprising: a first magnetic pole; a second magnetic pole; a laminate provided between the first magnetic pole and the second magnetic pole, the laminate including a first magnetic layer, 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, a fourth magnetic layer provided between the third magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer, a second non-magnetic layer provided between the first magnetic layer and the second magnetic layer and in contact with the first magnetic layer and the second magnetic layer, a third non-magnetic layer provided between the second magnetic layer and the third magnetic layer, a fourth non-magnetic layer provided between the third magnetic layer and the fourth magnetic layer and in contact with the third magnetic layer and the fourth magnetic layer, and a fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole; a first terminal electrically connected to the first magnetic pole; a second terminal electrically connected to the second magnetic pole; and a third terminal electrically connected to the third non-magnetic layer, a first thickness of the first magnetic layer in a first direction from the first magnetic layer toward the fourth magnetic layer is thicker than a second thickness of the second magnetic layer in the first direction and thicker than a third thickness of the third magnetic layer in the first direction, and a fourth thickness of the fourth magnetic layer in the first direction is thicker than the second thickness and thicker than the third thickness.

2. The magnetic head according to claim 1, wherein the first non-magnetic layer is in contact with the first magnetic pole and the first magnetic layer, and the fifth non-magnetic layer is in contact with the fourth magnetic layer and the second magnetic pole.

3. The magnetic head according to claim 1, wherein at least any one of the first non-magnetic layer, the second non-magnetic layer, the fourth non-magnetic layer, and the fifth non-magnetic layer includes at least one selected from a group consisting of Cu, Au, Cr, Al, V, and Ag.

4. The magnetic head according to claim 1, wherein the third non-magnetic layer includes at least one selected from a group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.

5. The magnetic head according to claim 1, wherein the third non-magnetic layer includes a first partial region and a second partial region, the first partial region overlaps the second magnetic layer in an opposite direction from the third non-magnetic layer toward the second magnetic layer, and the second partial region does not overlap the second magnetic layer in the opposite direction.

6. The magnetic head according to claim 1, wherein the third non-magnetic layer includes a first partial region and a second partial region, the first partial region overlaps the fourth magnetic layer in an opposite direction from the third non-magnetic layer toward the fourth magnetic layer, and the second partial region does not overlap the fourth magnetic layer in the opposite direction.

7. A magnetic recording apparatus, comprising the magnetic head according to claim 1 and a control portion electrically connected to the first terminal, the second terminal, and the third terminal. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The control section supplies a first current from the first terminal to the third terminal and a second current from the second terminal to the third terminal to the magnetic head.

8. The magnetic recording apparatus according to claim 7, Further comprising a third circuit; The magnetic head further comprises a coil; The third circuit supplies a recording current to the coil.

9. The magnetic recording apparatus according to claim 7, An alternating magnetic field is generated from the layered body in accordance with the first current and the second current.

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