Magnetic head and magnetic recording device

Abstract

A magnetic head and a magnetic recording device capable of improving recording density are provided. According to an embodiment, the magnetic head includes a first pole, a second pole, and a laminate provided between the first pole and the second pole. The laminate includes a first magnetic layer, a second magnetic layer provided between the second pole and the first magnetic layer, a third magnetic layer provided between the second pole and the second magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first pole, a second non-magnetic layer provided between the second magnetic layer and the first magnetic layer, a third non-magnetic layer provided between the third magnetic layer and the second magnetic layer, and a fourth non-magnetic layer provided between the second pole and the third magnetic layer. A first thickness of the first magnetic layer in a first direction from the first pole toward the second pole is thicker than a second thickness of the second magnetic layer in the first direction. A third thickness of the third magnetic layer in the first direction is thicker than the second thickness.

Description

[0001] This application is based on Japanese Patent Application No. 2021-028527 (Filing date: February 25, 2021) which is hereby incorporated by reference into this application in its entirety. This application claims priority from Japanese Patent Application No. 2021-028527. This application incorporates the entire contents of the application by reference. TECHNICAL FIELD

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

[0003] A magnetic head is used to record information 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 capable of increasing the recording density.

[0005] Technical Solution to the Problem

[0006] According to an embodiment of the present application, a magnetic head includes a first magnetic pole, a second magnetic pole, and a laminate 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 second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second magnetic layer and the first magnetic layer, a third non-magnetic layer provided between the third magnetic layer and the second magnetic layer, and a fourth non-magnetic layer provided between the second magnetic pole and the third magnetic layer. A first thickness of the first magnetic layer in a first direction from the first magnetic pole toward the second magnetic pole is thicker than a second thickness of the second magnetic layer in the first direction. A third thickness of the third magnetic layer in the first direction is thicker than the second thickness.

[0007] According to the magnetic head having the above-described structure, it is possible to provide a magnetic head and a magnetic recording device capable of increasing the recording density. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 (a) of FIG. 1 and Figure 1 (b) of FIG. 1 are schematic views illustrating a magnetic head according to a first embodiment.

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

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

[0011] Figure 4 (a) ~ (c) of FIG. 10 are graphs illustrating characteristics of the magnetic head. Figure 4 (b) of FIG. 10 is a graph illustrating characteristics of the magnetic head.

[0012] Figure 5 (a) and (b) of FIG. 11 are graphs illustrating characteristics of the magnetic head. Figure 5 (b) of FIG. 11 is a graph illustrating characteristics of the magnetic head.

[0013] Figure 6 is a graph illustrating characteristics of the magnetic head according to the first embodiment.

[0014] Figure 7 (a) and (b) of FIG. 12 are graphs illustrating characteristics of the magnetic head. Figure 7 (b) of FIG. 12 is a graph illustrating characteristics of the magnetic head.

[0015] Figure 8 (a) and (b) of FIG. 13 are graphs illustrating characteristics of the magnetic head. Figure 8 (b) of FIG. 13 is a graph illustrating characteristics of the magnetic head.

[0016] Figure 9 is a schematic cross-sectional view illustrating the magnetic head according to the embodiment.

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

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

[0019] Figure 12 is a schematic perspective view illustrating the magnetic recording apparatus according to the embodiment.

[0020] Figure 13 (a) and (b) of FIG. 15 are schematic perspective views illustrating a part of the magnetic recording apparatus according to the embodiment. Figure 13 (b) of FIG. 15 is a schematic perspective view illustrating a part of the magnetic recording apparatus according to the embodiment.

[0021] Reference Signs

[0022] 20 stack; 20D electric circuit; 21-23 1st magnetic layer-3rd magnetic layer; 30D recording circuit; 30F medium facing surface; 30c coil; 30i insulating portion; 31, 32 1st magnetic pole, 2nd magnetic pole; 33 shield; 41-44 1st non-magnetic layer-4th non-magnetic layer; 60 recording portion; 70 reproducing portion; 71 magnetic reproducing element; 72a, 72b 1st reproducing magnetic shield, 2nd reproducing magnetic shield; 80 magnetic recording medium; 81 magnetic recording layer; 82 medium substrate; 83 magnetization; 85 medium moving direction; θ1 angle; 110 magnetic head; 150 magnetic recording device; 154 suspension; 155 arm; 156 voice coil motor; 157 bearing 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 magnetic recording device; AR, AR1 arrow; D1 1st direction; Iw recording current; MD1, MD2 1st model, 2nd model; Mz magnetization; Mz1-Mz3 1st magnetization-3rd magnetization; OS oscillation strength; RR2, RR3 ratio; Rx resistance; Rxa1-Rxa4 1st resistance-4th resistance; Rxa average value; Rxd change rate; Rxd1-Rxd4 1st change rate-4th change rate; T1, T2 1st terminal, 2nd terminal; W1, W2 1st wiring, 2nd wiring; ic current; ix current; ix1-ic4 1st current-4th current; je electron flow; t1-t3 1st thickness-3rd thickness; t41-t44 thickness; tm time DETAILED DESCRIPTION

[0023] Hereinafter, each embodiment of the present application will be described with reference to the drawings.

[0024] The drawings are schematic or conceptual, and the relationship between the thickness and width of each portion, the ratio of the sizes of portions, and the like are not limited to be necessarily the same as in reality. Even in the case of representing the same portions, the dimensions and ratios of each other are sometimes represented to be different from each other depending on the drawings.

[0025] In the present application specification and each drawing, the same reference numerals are given to elements similar to those described in the foregoing with respect to the drawings already appearing, and detailed description is appropriately omitted.

[0026] (1st Embodiment)

[0027] Figure 1 (a) and (b) of FIG. 1 are schematic diagrams exemplifying a magnetic head related to the 1st embodiment. Figure 1 (a) of FIG. 2 is a sectional view.

[0028] Figure 1 (a) of FIG. 3 is a sectional view. Figure 1(b) is from Figure 1 a plan view observed from an arrow AR1 of (a).

[0029] Figure 2 is a schematic cross-sectional view illustrating a magnetic recording device according to the first embodiment.

[0030] As Figure 2 illustrated, a magnetic recording device 210 according to the embodiment includes a magnetic head 110 and an electric circuit 20D. The magnetic recording device 210 can also include a magnetic recording medium 80. In the magnetic recording device 210, at least a recording operation is performed. In the recording operation, the magnetic head 110 is used to record information in the magnetic recording medium 80.

[0031] The magnetic head 110 includes a recording portion 60. As described later, the magnetic head 110 can also include a reproducing portion. The recording portion 60 includes a first magnetic pole 31, a second magnetic pole 32, and a laminate 20. The laminate 20 is provided between the first magnetic pole 31 and the second magnetic pole 32.

[0032] 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 pole. The second magnetic pole 32 is, for example, a trailing shield. It can also be that the first magnetic pole 31 is a trailing shield and the second magnetic pole 32 is a main pole.

[0033] A direction from the magnetic recording medium 80 toward the magnetic head 110 is a Z-axis direction. One direction perpendicular to the Z-axis direction is an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is a Y-axis direction. The Z-axis direction corresponds to, for example, a height direction. The X-axis direction corresponds to, for example, a down track direction. The Y-axis direction corresponds to, for example, a cross track direction. The magnetic recording medium 80 and the magnetic head 110 relatively move along the down track direction. A magnetic field (a recording magnetic field) generated from the magnetic head 110 is applied to a desired position of the magnetic recording medium 80. Magnetization of the desired position of the magnetic recording medium 80 is controlled to a direction corresponding to the recording magnetic field. Thus, information is recorded in the magnetic recording medium 80.

[0034] A direction from the first magnetic pole 31 toward the second magnetic pole 32 is a first direction D1. The first direction D1 substantially follows the X-axis direction. In the embodiment, the first direction D1 can also be inclined at a small angle with respect to the X-axis direction.

[0035] As Figure 2As shown, the coil 30c is provided. In this example, a part of the coil 30c is located between the 1st pole 31 and the 2nd pole 32. In this example, the shield 33 is provided. In the X-axis direction, the 1st pole 31 is located between the shield 33 and the 2nd pole 32. The other part of the coil 30c is located between the shield 33 and the 1st pole 31. The insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 can also include a side shield (not shown).

[0036] As shown in (a) and (b) of FIG. 10, the coil 30c is provided. In this example, a part of the coil 30c is located between the 1st pole 31 and the 2nd pole 32. In this example, the shield 33 is provided. In the X-axis direction, the 1st pole 31 is located between the shield 33 and the 2nd pole 32. The other part of the coil 30c is located between the shield 33 and the 1st pole 31. The insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 can also include a side shield (not shown). Figure 2 As shown, the recording current Iw is supplied from the recording circuit 30D to the coil 30c. The recording magnetic field corresponding to the recording current Iw is applied from the 1st pole 31 to the magnetic recording medium 80.

[0037] As shown in (a) and (b) of FIG. 10, the coil 30c is provided. In this example, a part of the coil 30c is located between the 1st pole 31 and the 2nd pole 32. In this example, the shield 33 is provided. In the X-axis direction, the 1st pole 31 is located between the shield 33 and the 2nd pole 32. The other part of the coil 30c is located between the shield 33 and the 1st pole 31. The insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 can also include a side shield (not shown). Figure 2 As shown, the 1st pole 31 includes the medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F is, for example, opposed to the magnetic recording medium 80. The medium facing surface 30F is, for example, along the X-Y plane.

[0038] As shown in (a) and (b) of FIG. 10, the coil 30c is provided. In this example, a part of the coil 30c is located between the 1st pole 31 and the 2nd pole 32. In this example, the shield 33 is provided. In the X-axis direction, the 1st pole 31 is located between the shield 33 and the 2nd pole 32. The other part of the coil 30c is located between the shield 33 and the 1st pole 31. The insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 can also include a side shield (not shown). Figure 2 As shown, the recording current Iw is supplied from the recording circuit 30D to the coil 30c. The recording magnetic field corresponding to the recording current Iw is applied from the 1st pole 31 to the magnetic recording medium 80.

[0039] As shown in (a) and (b) of FIG. 10, the coil 30c is provided. In this example, a part of the coil 30c is located between the 1st pole 31 and the 2nd pole 32. In this example, the shield 33 is provided. In the X-axis direction, the 1st pole 31 is located between the shield 33 and the 2nd pole 32. The other part of the coil 30c is located between the shield 33 and the 1st pole 31. The insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 can also include a side shield (not shown). Figure 1 As shown, the 1st pole 31 includes the medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F is, for example, opposed to the magnetic recording medium 80. The medium facing surface 30F is, for example, along the X-Y plane. Figure 1 As shown, the 1st pole 31 includes the medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F is, for example, opposed to the magnetic recording medium 80. The medium facing surface 30F is, for example, along the X-Y plane. Figure 1 As shown, the 1st pole 31 includes the medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F is, for example, opposed to the magnetic recording medium 80. The medium facing surface 30F is, for example, along the X-Y plane. Figure 1 As shown, the 1st pole 31 includes the medium facing surface 30F. The medium facing surface 30F is, for example, an ABS (Air Bearing Surface). The medium facing surface 30F is, for example, opposed to the magnetic recording medium 80. The medium facing surface 30F is, for example, along the X-Y plane.

[0040] The first magnetic layer 21 is provided between the first magnetic pole 31 and the second magnetic pole 32. The second magnetic layer 22 is provided between the second magnetic pole 32 and the first magnetic layer 21. The third magnetic layer 23 is provided between the second magnetic pole 32 and the second magnetic layer 22. The first non-magnetic layer 41 is provided between the first magnetic layer 21 and the first magnetic pole 31. The second non-magnetic layer 42 is provided between the second magnetic layer 22 and the first magnetic layer 21. The third non-magnetic layer 43 is provided between the third magnetic layer 23 and the second magnetic layer 22. The fourth non-magnetic layer 44 is provided between the second magnetic pole 32 and the third magnetic layer 23.

[0041] For example, the first nonmagnetic layer 41 may be in contact with the first magnetic layer 21 and the first magnetic pole 31. The second nonmagnetic layer 42 may be in contact with the second magnetic layer 22 and the first magnetic layer 21. The third nonmagnetic layer 43 may be in contact with the third magnetic layer 23 and the second magnetic layer 22. The fourth nonmagnetic layer 42 may be in contact with the second magnetic pole 32 and the third magnetic layer 23.

[0042] The first magnetic layer 21 , the second magnetic layer 22 , and the third magnetic layer 23 contain a first element, and the first element contains at least one selected from Fe, Co, and Ni. These magnetic layers may contain, for example, an FeCo alloy.

[0043] The first non-magnetic layer 41 includes, for example, at least one selected from Cu, Au, Cr, Al, V, and Ag. The fourth non-magnetic layer 44 includes, for example, at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. Thus, in the laminate 20, the first non-magnetic layer 41 and the fourth non-magnetic layer 44 are asymmetric.

[0044] The third non-magnetic layer 43 may include, for example, at least one selected from Cu, Au, Cr, Al, V, and Ag. The second non-magnetic layer 42 may include, for example, at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. Thus, in the laminate 20, the third non-magnetic layer 43 and the second non-magnetic layer 42 may be asymmetric.

[0045] like Figure 1 As shown in (b), current ic is supplied to the laminate 20. Current ic is supplied from the above-mentioned electric circuit 20D, for example. Figure 1 As shown in (b), the current ic has a direction from the first magnetic layer 21 to the second magnetic layer 22. Figure 1 As shown in FIG. 2( b ), the electron current je accompanying the current ic has a direction from the second magnetic layer 22 toward the first magnetic layer 21 . The direction of the current ic is from the first magnetic pole 31 toward the second magnetic pole 32 .

[0046] For example, by flowing a current ic above a threshold value through the stack 20, the magnetization of the magnetic layer included in the stack 20 oscillates. The stack 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 stack 20. The alternating magnetic field generated in the stack 20 is applied to the magnetic recording medium 80 to assist writing to the magnetic recording medium 80. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented.

[0047] In the magnetic head 110, the first magnetic layer 21 and the third magnetic layer 23 function as, for example, oscillation layers. For example, the magnetization of the first magnetic layer 21 and the magnetization of the third magnetic layer 23 rotate in opposite phases (e.g., while maintaining opposite directions). The second magnetic layer 22 functions as, for example, a spin injection layer. The direction of the magnetization of the second magnetic layer 22 can change during operation.

[0048] like Figure 1 As shown in (b), the thickness of the first magnetic layer 21 along the first direction D1 (the direction from the first magnetic pole 31 toward the second magnetic pole 32) is set to a first thickness t1. The thickness of the second magnetic layer 22 along the first direction D1 is set to a second thickness t2. The thickness of the third magnetic layer 23 along the first direction D1 is set to a third thickness t3. In the embodiment, the first thickness t1 is thicker than the second thickness t2. The third thickness t3 is thicker than the second thickness t2. This facilitates oscillation, as described later.

[0049] The thickness of the first non-magnetic layer 41 along the first direction D1 is set to thickness t41. The thickness of the second non-magnetic layer 42 along the first direction D1 is set to thickness t42. The thickness of the third non-magnetic layer 43 along the first direction D1 is set to thickness t43. The thickness of the fourth non-magnetic layer 44 along the first direction D1 is set to thickness t44. These thicknesses are, for example, greater than 0.5 nm and less than 6 nm. By having these thicknesses greater than 0.5 nm, it is easier to reduce magnetic coupling, for example. For example, it is easier to obtain high oscillation intensity. By having these thicknesses less than 6 nm, it is easier to increase spin transmittance, for example. For example, it is easier to obtain high oscillation intensity. For example, it is possible to reduce the recording gap. For example, it is easier to obtain high recording density.

[0050] Hereinafter, an example of simulation results of oscillation behavior in the stacked body 20 will be described. In the first model of the simulation, Figure 1the structure shown in (b) of FIG. 1. That is, the first magnetic pole 31, the second magnetic pole 32, the first to third magnetic layers 21 to 23, and the first to fourth non-magnetic layers 41 to 44 are provided. As the physical property values of the first magnetic layer 21 and the third magnetic layer 23, the physical property values of Fe 70 Co 30 alloy. The first thickness tl is 6.5 nm. The third thickness t3 is 6.5 nm. The second thickness t2 is 3 nm. As the physical property values of the second magnetic layer 22, the physical property values of Fe 78 Ni 22 alloy can be used. In this example, the FeNi alloy is Fe 70 Co 30 alloy. As the physical property values of the third magnetic layer 23, the physical property values of Fe 78 Ni 22 alloy can be used. In this way, in the first model, the first thickness tl and the third thickness t3 are thicker than the second thickness t2. As the physical property values of the first non-magnetic layer 41 and the third non-magnetic layer 43, the physical property values of Cu can be used. As the physical property values of the second non-magnetic layer 42 and the fourth non-magnetic layer 44, the physical property values of Ta can be used. The thicknesses t41 to t44 are 2 nm.

[0051] In the second model, the first magnetic pole 31, the second magnetic pole 32, the first to third magnetic layers 21 to 23, and the first to fourth non-magnetic layers 41 to 44 are provided. The first thickness tl is 6.5 nm. The second thickness t2 is 6.5 nm. The third thickness t3 is 3 nm. As the physical property values of the first magnetic layer 21 and the second magnetic layer 22, the physical property values of Fe 70 Co 30 alloy can be used. As the physical property values of the third magnetic layer 23, the physical property values of Fe 78 Ni 22 alloy can be used. In this way, in the second model, the first thickness tl and the second thickness t2 are thicker than the third thickness t3. The structure other than this in the second model is the same as that in the first model. In the second model, the first magnetic layer 21 and the second magnetic layer 22 function as, for example, an oscillation layer.

[0052] In these models, the oscillation characteristics of the magnetization when the current ic exemplified in (b) of FIG. 1 is supplied are simulated. Figure 1

[0053] is a graph in which the characteristics of the magnetic head are exemplified. Figure 3

[0054] Figure 3The horizontal axis represents the current ic (relative value). The vertical axis represents the oscillation intensity OS. In the first simulation model, the oscillation intensity OS is the sum of the product of the oscillation amplitude of the magnetization of the first magnetic layer 21 and the first thickness t1, and the product of the oscillation amplitude of the magnetization of the third magnetic layer 23 and the third thickness t3. In the second simulation model, the oscillation intensity OS is the sum of the product of the oscillation amplitude of the magnetization of the first magnetic layer 21 and the first thickness t1, and the product of the oscillation amplitude of the magnetization of the second magnetic layer 22 and the second thickness t2. When the oscillation intensity OS is high, for example, the recording density based on MAMR is easily improved.

[0055] like Figure 3 As shown, in the region where the current ic is small, the oscillation intensity OS of the first model MD1 is higher than that of the second model MD2. This shows that a high oscillation intensity OS can be achieved by making the first thickness t1 and the third thickness t3 thicker than the second thickness t2. For example, in the first model MD1, during the oscillation state, the magnetization of the second magnetic layer 22 and the magnetization of the third magnetic layer have components with the same orientation in the first direction. For example, in the second model MD2, during the oscillation state, the magnetization of the second magnetic layer 22 and the magnetization of the third magnetic layer have different orientations with respect to the first direction. This difference may be related to the difference in oscillation intensity OS. For example, in the second model MD2, the fact that a current is required to cause the magnetization of the second magnetic layer 22 and the magnetization of the third magnetic layer to have different orientations in the first direction is believed to be related to the difference in oscillation intensity OS.

[0056] According to the embodiments, for example, a high oscillation strength OS can be obtained. More stable oscillation can be obtained. According to the embodiments, stable MAMR can be implemented. A magnetic head capable of improving recording density can be provided.

[0057] Figure 4 (a)~ Figure 4 (c) is a graph illustrating the characteristics of the magnetic head.

[0058] Figure 4 The horizontal axis of (a) is the first thickness t1. Figure 4 In (a), the second thickness t2 is 3 nm, and the third thickness t3 is 12 nm. Figure 4 The horizontal axis of (b) is the second thickness t2. Figure 4 In (b), the first thickness t1 is 8 nm, and the third thickness t3 is 8 nm. Figure 4 The horizontal axis of (c) is the third thickness t3. Figure 4 In (c), the first thickness t1 is 12 nm and the second thickness t2 is 3 nm. In these figures, the current ic supplied to the stacked body 20 is 1.2×10 8 A / cm 2 The vertical axis of these graphs is the oscillation intensity OS.

[0059] like Figure 4 As shown in (a), the first thickness t1 is preferably 5 nm or more and 15 nm or less. This allows for a high oscillation strength OS to be obtained.

[0060] like Figure 4 As shown in (c), the third thickness t3 is preferably 5 nm or more and 15 nm or less. This can obtain a high oscillation strength OS.

[0061] like Figure 5 As shown in (b), when the second thickness t2 is in the range of 1 nm to 10 nm, the oscillation intensity OS does not substantially change. Therefore, the second thickness t2 can also be thin. For example, the second thickness t2 can be less than 5 nm. By thinning the second thickness t2, the thickness of the stack 20 becomes thinner. For example, the distance (recording gap) between the first magnetic pole 31 and the second magnetic pole 32 can be reduced. Thus, a high recording density can be easily obtained. For example, the second thickness t2 can also be less than 3 nm. For example, the second thickness t2 can also be less than 2 nm.

[0062] Figure 5 (a) and Figure 5 (b) is a graph illustrating the characteristics of the magnetic head.

[0063] Figure 5 The horizontal axis of (a) represents the ratio RR3. The ratio RR3 is the ratio of the third thickness t3 to the first thickness t1. Figure 5 The horizontal axis of (b) is the ratio RR2. The ratio RR2 is the ratio of the second thickness t2 to the first thickness t1. Figure 5 In (a), the ratio RR2 is 0.3. Figure 5 In (b), the ratio RR3 is 1.

[0064] like Figure 5 As shown in (a), the ratio RR3 is preferably close to 1. This allows for a high oscillation strength OS. For example, the third thickness t3 is preferably 0.7 times or more and 1.7 times or less of the first thickness t1. For example, the third thickness t3 may be 0.6 times or more and 1.25 times or less of the first thickness t1. This allows for a high oscillation strength OS.

[0065] like Figure 6In (b) of FIG. 17, the oscillation strength OS does not substantially change in a range where the ratio RR2 is 0.2 to 1.3. The ratio RR2 is preferably low. The recording gap is easily reduced. For example, the second thickness t2 is preferably, for example, 0.7 times or less of the first thickness t1. The second thickness t2 can also be, for example, 0.5 times or less of the first thickness t1. The second thickness t2 is preferably, for example, 0.7 times or less of the third thickness t3. The second thickness t2 can also be, for example, 0.5 times or less of the third thickness t3. The recording gap is easily reduced. A high recording density is easily obtained.

[0066] As described above, the first magnetic layer 21, the second magnetic layer 22, and the third magnetic layer 23 include the first element including at least one selected from Fe, Co, and Ni. In an embodiment, the first magnetic layer 21, the second magnetic layer 22, and the third magnetic layer 23 substantially do not include the second element including at least one selected from Cr, V, Mn, Ti, and Sc. Alternatively, the concentration of the second element in the first magnetic layer 21, the second magnetic layer 22, and the third magnetic layer 23 is less than 10 atm%. For example, the first magnetic layer 21 to the third magnetic layer 23 have, for example, positive polarization. In such a magnetic layer, stable oscillation is easily obtained.

[0067] Figure 6 FIG. 18 is a schematic view illustrating a characteristic of the magnetic head according to the first embodiment.

[0068] Figure 6 The horizontal axis of FIG. 19 is time tm. The vertical axis is magnetization Mz (normalized value). In Figure 6 Examples relating to the first magnetization Mzl of the first magnetic layer 21, the second magnetization Mz2 of the second magnetic layer 22, and the magnetization Mz3 of the third magnetic layer 23 are shown in FIG. 20. As shown in Figure 6 When a current ic in a direction from the first magnetic layer 21 toward the second magnetic layer 22 is supplied to the laminate 20, the first magnetization Mzl and the third magnetization Mz3 rotate in opposite phases (for example, in a state where the directions are opposite) as shown in Figure 7 The second magnetization Mz2 of the second magnetic layer 22 is also exemplified in FIG. 20. In this example, the second magnetization Mz2 also rotates. The phase of the second magnetization Mz2 is different from the phase of the first magnetization Mzl and different from the phase of the third magnetization Mz3. The period of the second magnetization Mz2 is the same as the period of the first magnetization Mzl and the same as the period of the third magnetization Mz3.

[0069] Figure 7 (a) of FIG. 21 and Figure 1 (b) of FIG. 22 are schematic views illustrating characteristics of the magnetic head according to the first embodiment.

[0070] These graphs show examples of the characteristics of the magnetic head 110 when a current ix is supplied to the laminate 20, and a recording current Iw is supplied to the coil 30c. In this case, a recording magnetic field is generated from at least either one of the first magnetic pole 31 and the second magnetic pole 32. A part of the recording magnetic field is applied to the laminate 20. The direction of the current ix is opposite to the direction of the current ic exemplified in (c) of FIG. 12. The direction of the current ix has a direction from the second magnetic layer 22 toward the first magnetic layer 21. The current ix is a negative current. Figure 7 The horizontal axis of (a) of FIG. 13 is the time-wise average value Rxa of the resistance Rx of the laminate 20. By the time-wise average, the influence of noise and the like can also be suppressed, for example.

[0071] Figure 7 The horizontal axis of (b) of FIG. 13 is the current ix supplied to the laminate 20. The current ix is indicated by a relative value. Figure 7 The horizontal axis of (b) of FIG. 13 is the current ix supplied to the laminate 20. The current ix is indicated by a relative value. Figure 7 The horizontal axis of (b) of FIG. 13 is the current ix supplied to the laminate 20. The current ix is indicated by a relative value. Figure 7 The horizontal axis of (b) of FIG. 13 is the current ix supplied to the laminate 20. The current ix is indicated by a relative value.

[0072] As shown in (a) of FIG. 13, under the first current ixl, the time-wise average value Rxa of the resistance Rx of the laminate 20 is a first resistance Rxa1. Under the second current ix2, the average value Rxa is a second resistance Rxa2. Under the third current ix3, the average value Rxa is a third resistance Rxa3. The absolute value of the first current ixl is larger than the absolute value of the second current ix2, and is smaller than the absolute value of the third current ix3. The first resistance Rxa1 is higher than the second resistance Rxa2, and is lower than the third resistance Rxa3. Figure 7 As shown in (b) of FIG. 13, under the first current ixl, the rate of change Rxd of the time-wise average value Rxa of the resistance Rx is a first rate of change Rxd1. Under the second current ix2, the rate of change Rxd is a second rate of change Rxd2. Under the third current ix3, the rate of change Rxd is a third rate of change Rxd3. The absolute value of the first rate of change Rxd1 is larger than the absolute value of the second rate of change Rxd2, and is larger than the absolute value of the third rate of change Rxd3. The absolute value of the second rate of change Rxd2 can also be smaller than the absolute value of the third rate of change Rxd3.

[0073] Figure 7 As shown in (a) of FIG. 13, under the fourth current ix4, the time-wise average value Rxa of the resistance Rx of the laminate 20 is a fourth resistance Rxa4. The absolute value of the fourth current ix4 is larger than the absolute value of the third current ix3. The fourth resistance Rxa4 can also be higher than the first resistance Rxa1.

[0074] As shown in (b) of FIG. 13, under the fourth current ix4, the rate of change Rxd of the time-wise average value Rxa of the resistance Rx is a fourth rate of change Rxd4. The absolute value of the fourth current ix4 is larger than the absolute value of the third current ix3. The fourth rate of change Rxd4 can also be larger than the first rate of change Rxd1. Figure 7 As shown in (b) of FIG. 13, under the fourth current ix4, the rate of change Rxd of the time-wise average value Rxa of the resistance Rx is a fourth rate of change Rxd4. The absolute value of the fourth current ix4 is larger than the absolute value of the third current ix3. The fourth rate of change Rxd4 can also be larger than the first rate of change Rxd1.

[0075] Figure 8 ​​As shown in (b), under the fourth current ix4, the rate of change Rxd of the temporal average value Rxa of the resistance Rx is the fourth rate of change Rxd4. The absolute value of the first rate of change Rxd1 may be greater than the absolute value of the fourth rate of change Rxd4. Under the fourth current ix4, the third magnetic layer 23 may also function as an oscillation layer.

[0076] This characteristic is likely related to the fact that the third thickness t3 of the third magnetic layer 23 is thicker than the second thickness t2 of the second magnetic layer 22. In this combination, when a negative current ix is ​​supplied, the spin torque reflected by the third magnetic layer 23 acts on the second magnetic layer 22. For example, as the absolute value of the current ix increases, it is believed that the magnetization of the second magnetic layer 22 reverses, causing the second and third magnetic layers 22 and 23 to become closer to antiparallel, increasing the resistance. This is also believed to increase the rate of change in resistance.

[0077] Figure 8 (a) and Figure 1 (b) is a schematic diagram illustrating the characteristics of the magnetic head according to the first embodiment.

[0078] These figures show other examples of the characteristics of the magnetic head 110 when the current ix is ​​supplied to the laminate 20 and the recording current Iw is supplied to the coil 30c. In the case of these figures, the current ix is ​​also supplied to the laminate 20 and the recording current Iw is supplied to the coil 30c. The direction of the current ix is ​​the same as that of the current ix. Figure 8 The direction of the current ic illustrated in (c) is opposite. Figure 8 (a) and Figure 8 The horizontal axis of (b) represents the current ix supplied to the stacked body 20 . Figure 8 The vertical axis of (a) represents the temporal average value Rxa of the resistance Rx of the laminate 20 . Figure 8 The vertical axis of (b) represents the rate of change Rxd of the temporal average value of the resistance Rx of the laminate 20 when the absolute value of the current ix is ​​reduced.

[0079] like Figure 8 As shown in (a), the average value Rxa of the resistance Rx may be inclined overall with respect to the current ix (for example, a characteristic of a quadratic function). Such a characteristic is based on, for example, a temperature rise of the stacked body 20 caused by the current ix.

[0080] like Figure 8 As shown in (a), under the first current ix1 to the third current ix3, the average value Rxa is the first resistor Rxa1 to the third resistor Rxa3, respectively. The absolute value of the first current ix1 is larger than the absolute value of the second current ix2 and smaller than the absolute value of the third current ix3. The first resistor Rxa1 is higher than the second resistor Rxa2 and lower than the third resistor Rxa3.

[0081] likeFigure 8 As shown in (b), the change rates Rxd of the time-averaged value Rxa of the resistance Rx under the first current ix1 to the third current ix3 are the first change rate Rxd1 to the third change rate Rxd3, respectively. The absolute value of the first change rate Rxd1 is larger than the absolute value of the second change rate Rxd2, and larger than the absolute value of the third change rate Rxd3. The absolute value of the second change rate Rxd2 is smaller than the absolute value of the third change rate Rxd3.

[0082] like Figure 8 As shown in (a), under the fourth current ix4, the time average value Rxa of the resistance Rx of the stack 20 is the fourth resistance Rxa4. The absolute value of the fourth current ix4 is greater than the absolute value of the third current ix3. The fourth resistance Rxa4 can also be higher than the first resistance ix1. Figure 8 As shown in (b), under the fourth current ix4, the rate of change Rxd of the temporal average value Rxa of the resistance Rx is the fourth rate of change Rxd4. The absolute value of the fourth rate of change Rxd4 may be greater than the absolute value of the third rate of change Rxd3. Under the fourth current ix4, the third magnetic layer 23 may also function as an oscillation layer.

[0083] For example, you can also Figure 8 (a) and Figure 7 The characteristic shown in (b) is obtained by removing the component of the characteristic of the quadratic function. Figure 7 (a) and Figure 7 For example, the temperature rise of the stacked body 20 can be suppressed (e.g., by measuring a pulsed current), and the Figure 7 (a) and Figure 9 The characteristics illustrated in (b).

[0084] In an embodiment, the first magnetic pole 31 may include multiple magnetic regions arranged along the X-axis. The second magnetic pole 32 may also include multiple magnetic regions arranged along the X-axis. The boundaries between the multiple magnetic regions may be clear or unclear. For example, the multiple magnetic regions may be continuous.

[0085] Hereinafter, an example of a magnetic head and a magnetic recording medium 80 included in the magnetic recording device 210 according to the embodiment will be described.

[0086] Figure 9 This is a schematic cross-sectional view illustrating a magnetic head according to an embodiment.

[0087] like Figure 10As shown, in the magnetic head (e.g., magnetic head 110) according to the embodiment, the first direction D1 from the first magnetic pole 31 toward the second magnetic pole 32 may be inclined relative to the X-axis direction. The first direction D1 corresponds to the stacking direction of the stacked body 20. The X-axis direction is along the medium-facing surface 30F. The absolute value of the angle between the first direction D1 and the medium-facing surface 30F is defined as angle θ1. Angle θ1 is, for example, not less than 15 degrees and not more than 30 degrees. Angle θ1 may also be 0 degrees.

[0088] When the first direction D1 is tilted relative to the X-axis direction, the thickness of the layer corresponds to the length along the first direction D1. The structure in which the first direction D1 is tilted relative to the X-axis direction can be applied to any magnetic head involved in the embodiment. For example, the interface between the first magnetic pole 31 and the stacked body 20 and the interface between the stacked body 20 and the second magnetic pole 32 can also be tilted relative to the X-axis direction.

[0089] Hereinafter, an example of a magnetic head and a magnetic recording medium 80 included in the magnetic recording device 210 according to the embodiment will be described.

[0090] Figure 10 It is a schematic perspective view illustrating a magnetic recording device according to an embodiment.

[0091] like Figure 10 As shown, a magnetic head according to an embodiment (e.g., magnetic head 110) is used together with a magnetic recording medium 80. In this example, the magnetic head 110 includes a recording unit 60 and a reproducing unit 70. The recording unit 60 of the magnetic head 110 records information on the magnetic recording medium 80. The reproducing unit 70 reproduces the information recorded on the magnetic recording medium 80.

[0092] The magnetic recording medium 80 includes, for example, a dielectric substrate 82 and a magnetic recording layer 81 provided on the dielectric substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording unit 60.

[0093] The reproduction unit 70 includes, for example, a first reproduction magnetic shield 72a, a second reproduction magnetic shield 72b, and a magnetic reproduction element 71. The magnetic reproduction element 71 is disposed between the first reproduction magnetic shield 72a and the second reproduction magnetic shield 72b. The magnetic reproduction element 71 can output a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0094] like Figure 11 As shown, the magnetic recording medium 80 moves relative to the magnetic head 110 in the medium moving direction 85. At any position, information corresponding to the magnetization 83 of the magnetic recording layer 81 is controlled by the magnetic head 110. At any position, information corresponding to the magnetization 83 of the magnetic recording layer 81 is reproduced by the magnetic head 110.

[0095] Figure 11is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0096] Figure 12 A head slider is illustrated.

[0097] The magnetic head 110 is provided to the head slider 159. The head slider 159 contains, for example, Al203 / TiC or the like. The head slider 159 floats or contacts the magnetic recording medium while relatively moving with respect to the magnetic recording medium.

[0098] The head slider 159 has, for example, an air inflow side 159A and an air outflow side 159B. The magnetic head 110 is disposed at the side of the air outflow side 159B of the head slider 159 or the like. Thus, the magnetic head 110 floats or contacts the magnetic recording medium while relatively moving with respect to the magnetic recording medium.

[0099] Figure 12 is a schematic perspective view illustrating the magnetic recording device according to the embodiment.

[0100] As Figure 13 indicated, in the magnetic recording device 150 according to the embodiment, a rotary actuator can be used. A recording medium disk 180 is mounted to a spindle motor 180M. The recording medium disk 180 is rotated in the direction of an arrow AR by the spindle motor 180M. The spindle motor 180M responds to a control signal from a drive device control section. The magnetic recording device 150 according to the embodiment can also be provided with a plurality of recording medium disks 180. The magnetic recording device 150 can also include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). A nonvolatile memory such as a flash memory or the like can be used for the recording medium 181. For example, the magnetic recording device 150 can also be a hybrid HDD (Hard Disk Drive).

[0101] The head slider 159 performs recording and reproduction of information recorded on the recording medium disk 180. The head slider 159 is provided at the front end of a thin film-like suspension 154. A magnetic head according to the embodiment is provided near the front end of the head slider 159.

[0102] When the recording medium disk 180 is rotated, a pressing pressure generated by the suspension 154 and a pressure generated at a medium-facing surface (ABS) of the head slider 159 are balanced. A distance between the medium-facing surface of the head slider 159 and a surface of the recording medium disk 180 becomes a predetermined floating amount. In the embodiment, the head slider 159 can also be in contact with the recording medium disk 180. For example, a contact running type can be applied.

[0103] 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 frame portion, etc. The coil frame 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 coil frame portion of the arm 155. The magnetic circuit includes a permanent magnet and an opposing magnetic yoke. A drive coil is provided between the permanent magnet and the opposing magnetic 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.

[0104] The arm 155 is held by ball bearings provided at two locations, one above and one below, on the bearing portion 157. The arm 155 is rotatable and slidable by the voice coil motor 156. The magnetic head can be moved to any position on the recording medium disk 180.

[0105] Figure 13 (a) and Figure 13 (b) is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0106] Figure 13 (a) illustrates a partial structure of the magnetic recording device and is an enlarged perspective view of the head stack assembly 160 . Figure 13 (b) is a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA) 158 that is a part of the head stack assembly 160 .

[0107] like Figure 13 As 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 direction in which the support frame 161 extends is opposite to the direction in which the head gimbal assembly 158 extends. The support frame 161 supports the coil 162 of the voice coil motor 156.

[0108] like ​ As shown in FIG. 1( b ), the head gimbal assembly 158 includes an arm 155 extending from a bearing portion 157 and a suspension 154 extending from the arm 155 .

[0109] A head slider 159 is provided at the front end of the suspension 154. The head slider 159 is provided with the magnetic head according to the embodiment.

[0110] The head assembly (head gimbal assembly) 158 according to the embodiment includes the magnetic head according to 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.

[0111] The suspension 154 has, for example, a lead wire (not shown) for recording and reproducing a signal. The suspension 154 can also have, for example, a lead wire (not shown) for a heater for a floating amount adjustment. The suspension 154 can also have, for example, a lead wire (not shown) for a spin transfer torque oscillator, and the like. These lead wires are electrically connected to the plurality of electrodes provided to the magnetic head.

[0112] A signal processing section 190 is provided in the magnetic recording apparatus 150. The signal processing section 190 performs recording and reproducing of a signal to and from the magnetic recording medium using the magnetic head. The input and output lines of the signal processing section 190 are connected to the electrode pads of the head gimbal assembly 158, for example, and are electrically connected to the magnetic head.

[0113] The magnetic recording apparatus 150 according to the embodiment includes a magnetic recording medium, a magnetic head according to the embodiment, a movable section, a position control section, and a signal processing section. The movable section moves the magnetic recording medium and the magnetic head relatively in a state of being separated or contacted. The position control section aligns the position of the magnetic head to a predetermined recording position of the magnetic recording medium. The signal processing section performs recording and reproducing of a signal to and from the magnetic recording medium using the magnetic head.

[0114] For example, as the magnetic recording medium described above, a recording medium disk 180 can be used. The movable section described above includes, for example, a head slider 159. The position control section described above includes, for example, a head gimbal assembly 158.

[0115] The embodiment can also include the following technical solutions.

[0116] (Technical Solution 1)

[0117] A magnetic head comprising:

[0118] a first magnetic pole;

[0119] a second magnetic pole; and

[0120] a laminate provided between the first magnetic pole and the second magnetic pole,

[0121] the laminate includes:

[0122] a first magnetic layer;

[0123] a second magnetic layer provided between the second magnetic pole and the first magnetic layer;

[0124] a third magnetic layer provided between the second magnetic pole and the second magnetic layer;

[0125] a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole;

[0126] a second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer;

[0127] a third non-magnetic layer disposed between the third magnetic layer and the second magnetic layer; and

[0128] a fourth non-magnetic layer disposed between the second magnetic pole and the third magnetic layer,

[0129] a first thickness of the first magnetic layer in a first direction from the first magnetic pole toward the second magnetic pole is greater than a second thickness of the second magnetic layer in the first direction,

[0130] a third thickness of the third magnetic layer in the first direction is greater than the second thickness.

[0131] (Technical Solution 2)

[0132] the magnetic head according to Technical Solution 1,

[0133] the first non-magnetic layer is contiguous with the first magnetic layer and the first magnetic pole,

[0134] the second non-magnetic layer is contiguous with the second magnetic layer and the first magnetic layer,

[0135] the third non-magnetic layer is contiguous with the third magnetic layer and the second magnetic layer,

[0136] the fourth non-magnetic layer is contiguous with the second magnetic pole and the third magnetic layer.

[0137] (Technical Solution 3)

[0138] the magnetic head according to Technical Solution 1 or 2,

[0139] the third thickness is greater than or equal to 0.6 times and less than or equal to 1.7 times the first thickness.

[0140] (Technical Solution 4)

[0141] the magnetic head according to Technical Solution 1 or 2,

[0142] the third thickness is greater than or equal to 0.8 times and less than or equal to 1.25 times the first thickness.

[0143] (Technical Solution 5)

[0144] the magnetic head according to any one of Technical Solutions 1 to 4,

[0145] the second thickness is less than or equal to 0.7 times the first thickness.

[0146] (Technical Solution 6)

[0147] The magnetic head according to any one of the aspects 1 to 4,

[0148] The second thickness is 0.5 times or less of the first thickness.

[0149] (Aspect 7)

[0150] The magnetic head according to any one of the aspects 1 to 6,

[0151] The second thickness is 0.7 times or less of the third thickness.

[0152] (Aspect 8)

[0153] The magnetic head according to any one of the aspects 1 to 6,

[0154] The second thickness is 0.5 times or less of the third thickness.

[0155] (Aspect 9)

[0156] The magnetic head according to any one of the aspects 1 to 8,

[0157] The first thickness is 5 nm or more and 15 nm or less.

[0158] (Aspect 10)

[0159] The magnetic head according to any one of the aspects 1 to 9,

[0160] The third thickness is 5 nm or more and 15 nm or less.

[0161] (Aspect 11)

[0162] The magnetic head according to any one of the aspects 1 to 10,

[0163] The first non-magnetic layer contains at least one selected from Cu, Au, Cr, Al, V, and Ag,

[0164] The fourth non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0165] (Aspect 12)

[0166] The magnetic head according to any one of the aspects 1 to 11,

[0167] The third non-magnetic layer contains at least one selected from Cu, Au, Cr, Al, V, and Ag,

[0168] The second non-magnetic layer contains at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

[0169] (claim 13)

[0170] The magnetic head according to any one of claims 1 to 12,

[0171] The first magnetic layer, the second magnetic layer, and the third magnetic layer contain a first element, the first element containing at least one selected from Fe, Co, and Ni.

[0172] (claim 14)

[0173] The magnetic head according to claim 13,

[0174] The first magnetic layer, the second magnetic layer, and the third magnetic layer do not contain a second element, the second element containing at least one selected from Cr, V, Mn, Ti, and Sc,

[0175] or,

[0176] The concentration of the second element in the first magnetic layer, the second magnetic layer, and the third magnetic layer is less than 10 atm%.

[0177] (claim 15)

[0178] The magnetic head according to any one of claims 1 to 14,

[0179] A current in a direction from the first magnetic layer toward the second magnetic layer is supplied to the layered body.

[0180] (claim 16)

[0181] The magnetic head according to claim 15,

[0182] An alternating magnetic field is generated from the layered body when the current is supplied to the layered body.

[0183] (claim 17)

[0184] The magnetic head according to any one of claims 1 to 14,

[0185] The first magnetization of the first magnetic layer and the third magnetization of the third magnetic layer are rotated in mutually opposite directions when a current in a direction from the first magnetic layer toward the second magnetic layer is supplied to the layered body.

[0186] (claim 18)

[0187] The magnetic head according to any one of claims 1 to 17,

[0188] Further comprising a first terminal and a second terminal,

[0189] The first terminal is electrically connected to a portion of the laminate,

[0190] The second terminal is electrically connected to another portion of the laminate,

[0191] A current can be supplied between the first terminal and the second terminal.

[0192] (Technical Solution 19)

[0193] A magnetic recording device including:

[0194] The magnetic head according to any one of Technical Solutions 1 to 14; and

[0195] An electrical circuit,

[0196] The electrical circuit is capable of supplying a current to the laminate,

[0197] The current has a direction from the first magnetic layer toward the second magnetic layer.

[0198] (Technical Solution 20)

[0199] The magnetic recording device according to Technical Solution 19,

[0200] An alternating magnetic field is generated from the laminate when the electrical circuit supplies the current to the laminate.

[0201] According to the embodiments, a magnetic head and a magnetic recording device capable of improving recording density can be provided.

[0202] In the present specification, "perpendicular" and "parallel" are not only strict perpendicular and strict parallel, but also "perpendicular" and "parallel" including a deviation in a manufacturing process and the like, as long as they are substantially perpendicular and substantially parallel.

[0203] 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 structures of each element included in the magnetic head, the laminate, the magnetic layer, the non-magnetic layer, the wiring, and the like, as long as the present application can be similarly implemented and the same effects can be obtained by appropriately selecting them from the known range by those skilled in the art, they are included in the scope of the present application.

[0204] As long as the gist of the present application is included, technical solutions obtained by combining any two or more elements in each specific example within a technically feasible range are also included in the scope of the present application.

[0205] Furthermore, all magnetic heads and magnetic recording devices that can be implemented by those skilled in the art by appropriately modifying the design of the magnetic heads and magnetic recording devices described above as embodiments of the present invention also fall within the scope of the present invention as long as they include the spirit of the present invention.

[0206] Furthermore, it is understood that within the scope of the present invention, those skilled in the art can conceive of various changes and modifications, and that these changes and modifications also fall within the scope of the present invention.

[0207] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are intended to be within the scope and spirit of the invention and are also intended to be within the scope of the invention set forth in the claims and their equivalents.

Claims

1. A magnetic head comprising: 1st magnetic pole; 2nd magnetic pole; as well as a laminated body provided between the first magnetic pole and the second magnetic pole, The laminate comprises: 1st magnetic layer; a second magnetic layer disposed between the second magnetic pole and the first magnetic layer; a third magnetic layer disposed between the second magnetic pole and the second magnetic layer; a first non-magnetic layer disposed between the first magnetic layer and the first magnetic pole; a second non-magnetic layer disposed between the second magnetic layer and the first magnetic layer; a third non-magnetic layer provided between the third magnetic layer and the second magnetic layer; and a fourth non-magnetic layer provided between the second magnetic pole and the third magnetic layer; a first thickness of the first magnetic layer along a first direction from the first magnetic pole toward the second magnetic pole is thicker than a second thickness of the second magnetic layer along the first direction; A third thickness of the third magnetic layer along the first direction is thicker than the second thickness, The third thickness is not less than 0.7 times and not more than 1.7 times the first thickness, When a current equal to or greater than a threshold value in a direction from the first magnetic layer toward the second magnetic layer is supplied to the stacked body, the first magnetization of the first magnetic layer and the third magnetization of the third magnetic layer rotate in opposite phases.

2. The magnetic head according to claim 1, The first thickness is greater than or equal to 5 nm and less than or equal to 15 nm.

3. The magnetic head according to claim 1, The third thickness is greater than or equal to 5 nm and less than or equal to 15 nm.

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

5. The magnetic head according to claim 1, The first non-magnetic layer includes at least one selected from Cu, Au, Cr, Al, V and Ag, The fourth non-magnetic layer includes at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

6. The magnetic head according to claim 5, The third non-magnetic layer includes at least one selected from Cu, Au, Cr, Al, V and Ag, The second non-magnetic layer includes at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W.

7. The magnetic head according to claim 1, It also has a first terminal and a second terminal, The first terminal is electrically connected to a portion of the laminate. The second terminal is electrically connected to other parts of the laminate. Current can be supplied between the first terminal and the second terminal.

8. A magnetic recording device comprising: The magnetic head according to any one of claims 1 to 7; and electrical circuits, The electrical circuit is capable of supplying electric current to the stack, The current has a direction from the first magnetic layer toward the second magnetic layer.

9. The magnetic recording device according to claim 8, When the electric circuit supplies current to the stacked body, an alternating magnetic field is generated from the stacked body.

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