Magnetic head and magnetic recording device

Abstract

To provide a magnetic head and a magnetic recording device capable of improving recording density.SOLUTION: A magnetic head 110 includes first and second magnetic poles 31 and 32 and a laminate 20 provided between the first and second magnetic poles. The laminate includes: a first magnetic layer 21; a second magnetic layer 22 provided between the first magnetic layer and the second magnetic pole; a first non-magnetic layer 41 provided between the first magnetic layer and the second magnetic layer; a second non-magnetic layer 42 provided between the second magnetic layer and the second magnetic pole; and a third non-magnetic layer 43 provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element containing at least one of Fe, Co, and Ni. The second magnetic layer includes the first element and a second element containing at least one selected from a group consisting of Cr, V, Mn, Ti, and Sc. The first magnetic layer does not include the second element. The first thickness of the first magnetic layer is equal to or more than 0.25 times and equal to or less than 4 times the second thickness of the second magnetic layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a magnetic head and a magnetic recording device. [Background technology]

[0002] 2. Description of the Related Art A magnetic head is used to record information on a magnetic recording medium such as a hard disk drive (HDD). It is desirable to improve the recording density in magnetic heads and magnetic recording devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-277586 A Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present invention provide a magnetic head and a magnetic recording device that enable improvement in recording density. [Means for solving the problem]

[0005] According to an embodiment of the present invention, the 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 first magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first magnetic layer and the second magnetic layer, a second non-magnetic layer provided between the second magnetic layer and the second magnetic pole, and a third non-magnetic layer provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element including at least one of Fe, Co, and Ni. The second magnetic layer includes the first element and a second element including at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. The first magnetic layer does not include the second element. Or, the concentration of the second element in the first magnetic layer is lower than the concentration of the second element in the second magnetic layer. A first thickness of the first magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is 0.25 to 4 times a second thickness of the second magnetic layer along the first direction. [Brief description of the drawings]

[0006] [Figure 1] 1A and 1B are schematic views illustrating the magnetic head according to the first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view illustrating the magnetic recording device according to the first embodiment. [Diagram 3] FIG. 3 is a graph illustrating the characteristics of the magnetic head. [Figure 4] 4(a) and 4(b) are graphs illustrating the characteristics of the magnetic head. [Diagram 5] FIG. 5 is a graph illustrating the characteristics of the magnetic head. [Figure 6] 6A and 6B are schematic plan views illustrating the magnetic head according to the first embodiment. [Figure 7] 7A and 7B are schematic views illustrating the characteristics of the magnetic head according to the embodiment. [Figure 8] FIG. 8 is a schematic view illustrating the characteristics of the magnetic head according to the first embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view illustrating the magnetic head according to the embodiment. [Figure 10] FIG. 10 is a schematic perspective view illustrating the magnetic recording device according to the embodiment. [Figure 11] FIG. 11 is a schematic perspective view illustrating a portion of the magnetic recording device according to the embodiment. [Figure 12] FIG. 12 is a schematic perspective view illustrating the magnetic recording device according to the embodiment. [Figure 13] 13A and 13B are schematic perspective views illustrating a part of the magnetic recording device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

[0008] (First embodiment) 1A and 1B are schematic views illustrating the magnetic head according to the first embodiment. Fig. 1(a) is a cross-sectional view, and Fig. 1(b) is a plan view seen from the arrow AR1 in Fig. 1(a). FIG. 2 is a schematic cross-sectional view illustrating the magnetic recording device according to the first embodiment. 2, a magnetic recording device 210 according to the embodiment includes a magnetic head 110 and an electric circuit 20D. The magnetic recording device 210 may include a magnetic recording medium 80. At least a recording operation is performed in the magnetic recording device 210. In the recording operation, information is recorded on the magnetic recording medium 80 using the magnetic head 110.

[0009] The magnetic head 110 includes a recording section 60. As described below, the magnetic head 110 may also include a reproducing section. The recording section 60 includes a first magnetic pole 31, a second magnetic pole 32, and a laminate 20. The laminate 20 is provided between the first magnetic pole 31 and the second magnetic pole 32.

[0010] For example, a first magnetic pole 31 and a second magnetic pole 32 form a magnetic circuit. The first magnetic pole 31 is, for example, a main magnetic pole. The second magnetic pole 32 is, for example, a trailing shield.

[0011] The direction from the magnetic recording medium 80 to the magnetic head 110 is defined as the Z-axis direction. One direction perpendicular to the Z-axis direction is defined as the X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is defined as the Y-axis direction. The Z-axis direction corresponds to the height direction, for example. The X-axis direction corresponds to the down-track direction, for example. The Y-axis direction corresponds to the cross-track direction, for example. The magnetic recording medium 80 and the magnetic head 110 move relatively along the down-track direction. A magnetic field (recording magnetic field) generated by the magnetic head 110 is applied to a desired position on the magnetic recording medium 80. The magnetization of the desired position on the magnetic recording medium 80 is controlled to a direction according to the recording magnetic field. As a result, information is recorded on the magnetic recording medium 80.

[0012] The direction from the first magnetic pole 31 to the second magnetic pole 32 is defined as a first direction D1. The first direction D1 is substantially along the X-axis direction. In an embodiment, the first direction D1 may be inclined at a small angle with respect to the X-axis direction.

[0013] As shown in FIG. 2, a coil 30c is provided. In this example, a portion of the coil 30c is between the first magnetic pole 31 and the second magnetic pole 32. In this example, a shield 33 is provided. In the X-axis direction, the first magnetic pole 31 is between the shield 33 and the second magnetic pole 32. Another portion of the coil 30c is between the shield 33 and the first magnetic pole 31. An insulating portion 30i is provided between these multiple elements. The shield 33 is, for example, a leading shield. The magnetic head 110 may include a side shield (not shown).

[0014] 2, a recording current Iw is supplied to the coil 30c from the recording circuit 30D. A recording magnetic field corresponding to the recording current Iw is applied to the magnetic recording medium 80 from the first magnetic pole 31.

[0015] 2, the first magnetic pole 31 includes a medium facing surface 30F. The medium facing surface 30F is, for example, an air bearing surface (ABS). The medium facing surface 30F faces, for example, the magnetic recording medium 80. The medium facing surface 30F is along, for example, the XY plane.

[0016] 2, the electric circuit 20D is electrically connected to the laminate 20. In this example, the laminate 20 is electrically connected to the first magnetic pole 31 and the second magnetic pole 32. A first terminal T1 and a second terminal T2 are provided on the magnetic head 110. The first terminal T1 is electrically connected to the laminate 20 via the first wiring W1 and the first magnetic pole 31. The second terminal T2 is electrically connected to the laminate 20 via the second wiring W2 and the second magnetic pole 32. For example, a current (for example, a direct current) is supplied to the laminate 20 from the electric circuit 20D.

[0017] 1(a) and 1(b), the stack 20 includes a first magnetic layer 21, a second magnetic layer 22, a first non-magnetic layer 41, a second non-magnetic layer 42, and a third non-magnetic layer 43. In FIGS. 1(a) and 1(b), the insulating portion 30i is omitted.

[0018] The second magnetic layer 22 is provided between the first magnetic layer 21 and the second magnetic pole 32. The first non-magnetic layer 41 is provided between the first magnetic layer 21 and the second magnetic layer 22. The second non-magnetic layer 42 is provided between the second magnetic layer 22 and the second magnetic pole 32. The third non-magnetic layer 43 is provided between the first magnetic pole 31 and the first magnetic layer 21.

[0019] For example, the third non-magnetic layer 43 may be in contact with the first magnetic pole 31 and the first magnetic layer 21. The first non-magnetic layer 41 may be in contact with the first magnetic layer 21 and the second magnetic layer 22. The second non-magnetic layer 42 may be in contact with the second magnetic layer 22 and the second magnetic pole 32.

[0020] At least one of the first non-magnetic layer 41, the second non-magnetic layer 42, and the third non-magnetic layer 43 includes a third element. The third element includes, for example, at least one selected from the group consisting of Cu, Au, Cr, V, Al, and Ag. In a non-magnetic layer including such a material, for example, a high spin transmittance is obtained. For example, a high oscillation intensity is obtained.

[0021] At least one of the second nonmagnetic layer 42 and the third nonmagnetic layer 43 may contain a fourth element. The fourth element includes, for example, at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt, and W. In a nonmagnetic layer including such a material, for example, a low spin transmittance is obtained. For example, stable oscillation is easily obtained. At least one of the second nonmagnetic layer 42 and the third nonmagnetic layer 43 may include the above-mentioned third element and fourth element.

[0022] In the embodiment, the first magnetic layer 21 includes a first element. The first element includes at least one of Fe, Co, and Ni.

[0023] The second magnetic layer 22 includes a first element and a second element. The second element includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. The first magnetic layer 21 does not include the second element. Alternatively, the concentration of the second element in the first magnetic layer 21 is lower than the concentration of the second element in the second magnetic layer 22.

[0024] For example, the concentration of the second element in the second magnetic layer 22 is 10 atomic % or more and 80 atomic % or less. The second magnetic layer 22 containing such a material has, for example, a negative spin polarization. On the other hand, for example, the first magnetic layer 21 has a positive spin polarization.

[0025] As shown in Fig. 1(b), a current i c is supplied to the laminate 20. The current i c is supplied, for example, from the electric circuit 20D described above. As shown in Fig. 1(b), the current i c is oriented from the first magnetic layer 21 to the second magnetic layer 22. As shown in Fig. 1(b), an electron flow je accompanying the current i c is oriented from the second magnetic layer 22 to the first magnetic layer 21.

[0026] For example, when a current i c equal to or greater than a threshold flows through the stack 20, the magnetization of the magnetic layers included in the stack 20 oscillates. The stack 20 functions as, for example, a spin-torque oscillator (STO). As the current oscillates, an AC magnetic field (for example, a high-frequency magnetic field) is generated from the stack 20. The AC magnetic field generated by the stack 20 is applied to the magnetic recording medium 80, assisting writing to the magnetic recording medium 80. For example, microwave assisted magnetic recording (MAMR) can be implemented.

[0027] In the magnetic head 110, the first magnetic layer 21 and the second magnetic layer 22 function as, for example, an oscillation layer. For example, a negative transmitted spin torque from the second magnetic layer 22 acts on the first magnetic layer 21. For example, a spin torque reflected by the first magnetic layer 21 acts on the second magnetic layer 22. For example, the magnetization of the first magnetic layer 21 and the magnetization of the second magnetic layer 22 rotate while interacting with each other.

[0028] As shown in FIG. 1(b), the thickness of the first magnetic layer 21 along the first direction (the direction from the first magnetic pole 31 to the second magnetic pole 32) is defined as a first thickness t1. The thickness of the second magnetic layer 22 along the first direction is defined as a second thickness t2. In the embodiment, for example, the first thickness t1 may be the same as the second thickness t2. This makes it easier to obtain oscillation, as described later.

[0029] The thickness of the first non-magnetic layer 41 along the first direction is defined as thickness t41. The thickness of the second non-magnetic layer 42 along the first direction is defined as thickness t42. The thickness of the third non-magnetic layer 43 along the first direction is defined as thickness t43. These thicknesses are, for example, 0.5 nm or more and 6 nm or less. When these thicknesses are 0.5 nm or more, stable oscillation becomes easy. When these thicknesses are 6 nm or less, for example, the spin transmittance is easily increased. For example, high oscillation intensity is easily obtained.

[0030] An example of a simulation result regarding the oscillation behavior in the laminate 20 will be described below. In the simulation model, a configuration shown in FIG. 1(b) is provided. That is, a first magnetic pole 31, a second magnetic pole 32, a first magnetic layer 21, a second magnetic layer 22, and first to third non-magnetic layers 41 to 43 are provided. The oscillation characteristics of magnetization when a current ic (current equal to or greater than a threshold value) illustrated in FIG. 1(b) is supplied is simulated. In the simulation model, the physical property values ​​of the first magnetic layer 21 are Fe 70 Co 30 The physical properties of the alloy are used. 70 Cr 30 The physical property values ​​of the alloy are used. The physical property values ​​of Cu are used as the physical property values ​​of the first non-magnetic layer 41 and the third non-magnetic layer 43. The physical property value of Ta is used as the physical property value of the second non-magnetic layer 42. The thicknesses t41 to t43 are 2 nm.

[0031] FIG. 3 is a graph illustrating the characteristics of the magnetic head. In the simulation illustrated in FIG. 3, the ratio of the first thickness t1 to the second thickness t2 is changed while the sum of the first thickness t1 of the first magnetic layer 21 and the second thickness t2 of the second magnetic layer 22 is kept constant at 19 nm. The horizontal axis of FIG. 3 is the thickness ratio R1. The thickness ratio R1 is the ratio of the first thickness t1 to the second thickness t2 (i.e., t1 / t2). The vertical axis is the oscillation strength OS. The oscillation strength OS is the sum of the product of the amplitude of the oscillation of the magnetization of the first magnetic layer 21 and the first thickness t1 and the product of the amplitude of the oscillation of the magnetization of the second magnetic layer 22 and the second thickness t2. When the oscillation strength OS is high, for example, the recording density by MAMR is likely to be improved.

[0032] As shown in FIG. 3, when the thickness ratio R1 is close to 1, a high oscillation intensity OS is obtained. For example, when the thickness ratio R1 is 0.25 or more and 4 or less, stable oscillation is obtained. The thickness ratio R1 may be 0.33 or more, and a higher oscillation intensity OS is obtained. The thickness ratio R1 may be 3 or less, and a higher oscillation intensity OS is obtained.

[0033] In the embodiment, the first thickness t1 is preferably 0.25 to 4 times the second thickness t2. This provides a high oscillation intensity OS. Stable oscillation is obtained. The first thickness t1 may be 0.33 to 3 times the second thickness. A higher oscillation intensity OS is obtained. A more stable oscillation is obtained. According to the embodiment, stable MAMR can be implemented. A magnetic head capable of improving recording density can be provided.

[0034] 4(a) and 4(b) are graphs illustrating the characteristics of the magnetic head. The horizontal axis of FIG. 4(a) is the first thickness t1. .figure The horizontal axis of FIG. 4(b) is the second thickness t2. In FIG. 4(b), the first thickness t1 is 15 nm. In FIG. 4(a) and FIG. 4(b), the current i c supplied to the stack 20 is 2.5×10 8 A / cm 2 The vertical axis in FIG. 4(a) and FIG. 4(b) is the oscillation intensity OS.

[0035] As shown in FIG. 4(a), the first thickness t1 is preferably 5 nm or more. This allows a high oscillation intensity OS to be obtained. The first thickness t1 may be, for example, 20 nm or less. For example, the distance (for example, the recording gap) between the first magnetic pole 31 and the second magnetic pole 32 can be shortened. For example, a high recording density can be easily obtained.

[0036] As shown in FIG. 4(b), the second thickness t2 is preferably 5 nm or more. This allows a high oscillation intensity OS to be obtained. The second thickness t2 may be 20 nm or less. For example, the recording gap can be shortened. For example, a high recording density can be easily obtained.

[0037] FIG. 5 is a graph illustrating the characteristics of the magnetic head. 5, the horizontal axis represents the sum ts of the first thickness t1 and the second thickness t2, and the vertical axis represents the oscillation intensity OS.

[0038] As shown in FIG. 5, the sum ts of the first thickness t1 and the second thickness t2 is preferably 15 nm or more. This allows a high oscillation intensity OS to be obtained. The sum ts may be 40 nm or less. For example, the recording gap can be shortened. For example, a high recording density can be easily obtained.

[0039] 6A and 6B are schematic plan views illustrating the magnetic head according to the first embodiment. 6(a), the magnetic head 111 according to the embodiment includes a first magnetic pole 31, a second magnetic pole 32, and a laminate 20. In the magnetic head 111, the laminate 20 also includes a first magnetic layer 21, a second magnetic layer 22, a first non-magnetic layer 41, a second non-magnetic layer 42, and a third non-magnetic layer 43. In the magnetic head 111, at least one of the first magnetic layer 21 and the second magnetic layer 22 includes a plurality of regions. Other configurations of the magnetic head 111 may be similar to those of the magnetic head 110.

[0040] For example, the first magnetic layer 21 includes a first magnetic region 21a and a second magnetic region 21b. The second magnetic region 21b is between the first magnetic region 21a and the first non-magnetic layer 41. For example, the saturation magnetization of the first magnetic region 21a is larger than the saturation magnetization of the second magnetic region 21b. This makes it easier to obtain stable oscillation, for example.

[0041] For example, the saturation magnetization of the first magnetic region 21a is 1.2 times or more that of the second magnetic region 21b. This makes it easier to obtain stable oscillation. The saturation magnetization of the first magnetic region 21a may be 3 times or less that of the second magnetic region 21b. This makes it easier to obtain stable oscillation.

[0042] For example, the concentration of Fe in the first magnetic region 21a is higher than the concentration of Fe in the second magnetic region 21b. For example, the saturation magnetization of the first magnetic region 21a is likely to be greater than the saturation magnetization of the second magnetic region 21b. For example, the concentration of Ni in the first magnetic region 21a is lower than the concentration of Ni in the second magnetic region 21b. As a result, for example, the saturation magnetization of the first magnetic region 21a is likely to be greater than the saturation magnetization of the second magnetic region 21b. The boundary between the first magnetic region 21a and the second magnetic region 21b may be clear or unclear.

[0043] For example, the second magnetic layer 22 includes a third magnetic region 22c and a fourth magnetic region 22d. The fourth magnetic region 22d is between the third magnetic region 22c and the first non-magnetic layer 41. For example, the saturation magnetization of the third magnetic region 22c is larger than the saturation magnetization of the fourth magnetic region 22d. This makes it easier to obtain stable oscillation, for example.

[0044] For example, the saturation magnetization of the third magnetic region 22c is 1.2 times or more that of the fourth magnetic region 22d. This makes it easier to obtain stable oscillation. The saturation magnetization of the third magnetic region 22c may be 3 times or less that of the fourth magnetic region 22d. This makes it easier to obtain stable oscillation.

[0045] For example, the Fe concentration in the third magnetic region 22c is higher than the Fe concentration in the fourth magnetic region 22d. As a result, for example, the saturation magnetization of the third magnetic region 22c is likely to be greater than that of the fourth magnetic region 22d. For example, the concentration of the second element in the third magnetic region 22c is lower than that of the fourth magnetic region 22d. As a result, for example, the saturation magnetization of the third magnetic region 22c is likely to be greater than that of the fourth magnetic region 22d. The boundary between the third magnetic region 22c and the fourth magnetic region 22d may be clear or unclear.

[0046] 6(b), the magnetic head 112 according to the embodiment includes a first magnetic pole 31, a second magnetic pole 32, and a laminate 20. In the magnetic head 112, the laminate 20 includes a third magnetic layer 23 in addition to a first magnetic layer 21, a second magnetic layer 22, a first non-magnetic layer 41, a second non-magnetic layer 42, and a third non-magnetic layer 43. Other configurations of the magnetic head 112 may be similar to those of the magnetic head 110 or the magnetic head 111.

[0047] The third magnetic layer 23 is provided between the second magnetic layer 22 and the second non-magnetic layer 42. The third magnetic layer 23 includes a first element including at least one of Fe, Co, and Ni. The third magnetic layer 23 does not include a second element. Alternatively, the concentration of the second element in the third magnetic layer 23 is lower than the concentration of the second element in the second magnetic layer 22. As already described, the second element includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc.

[0048] For example, the saturation magnetization of the third magnetic layer 23 is higher than that of the second magnetic layer 22. This makes it easier to obtain stable oscillation, for example. The boundary between the third magnetic layer 23 and the first magnetic layer 21 may be clear or unclear. The third magnetic layer 23 may be continuous with the second magnetic layer 22.

[0049] In the magnetic head 112, the first thickness t1 of the first magnetic layer 21 is, for example, 0.8 to 1.25 times the sum of the third thickness t3 of the third magnetic layer 23 and the second thickness t2 of the second magnetic layer 22 along the first direction (the direction from the first magnetic pole 31 to the second magnetic pole 32). For example, a high oscillation intensity OS is obtained. Stable oscillation is obtained.

[0050] 7A and 7B are schematic views illustrating the characteristics of the magnetic head according to the embodiment. 7(a) and 7(b) are plots of the horizontal axis representing the write current Iw flowing through the coil 30c. The write magnetic field generated by at least one of the first magnetic pole 31 and the second magnetic pole 32 changes in response to the write current Iw flowing through the coil 30c. The write magnetic field is applied to the laminate 20. Thus, the horizontal axis represents the magnetic field applied to the laminate 20. The vertical axis represents the electrical resistance Rx of the laminate 20.

[0051] In Fig. 7(a), the current i c supplied to the laminate 20 is smaller than the threshold current I th of oscillation. In the example of Fig. 7(a), the current i c is, for example, 1.0 × 10 6 A / cm 2 In FIG. 7B, the current i c supplied to the laminate 20 is greater than the threshold current I th. In the example of FIG. 7B, the current i c is 1.0×10 8 A / cm 2 7(b) is 100 times the current ic in FIG. 7(a). FIG. 7(a) corresponds to the characteristics in a non-oscillating state. FIG. 7(b) corresponds to the characteristics in an oscillating state. These figures illustrate the characteristics of the average value of the electrical resistance Rx over time. When the laminate 20 is oscillating, the electrical resistance Rx changes with the oscillation. The time-averaged resistance is used as the electrical resistance Rx. The time-averaged resistance can also suppress the effects of noise, for example.

[0052] As shown in FIG. 7(a), when the current ic is sufficiently smaller than the threshold current Ith, the electrical resistance Rx increases as the absolute value of the recording current Iw (i.e., the magnetic field) increases. When the absolute value of the recording current Iw is sufficiently large, the electrical resistance Rx saturates. For example, the recording current Iw when the electrical resistance Rx saturates is 50 mA. The magnetic field at this time is about 15,000 Oe.

[0053] In the magnetic recording device head according to the embodiment, for example, the characteristic illustrated in FIG. 7(a) occurs. As shown in FIG. 7(a), the electrical resistance Rx of the laminate 20 is a first resistance Rx1 when the recording current Iw is a first current I1. The electrical resistance Rx is a second resistance Rx2 when the recording current Iw is a second current I2. The electrical resistance Rx is a third resistance Rx3 when the recording current Iw is a third current I3. The absolute value of the first current I1 is smaller than the absolute value of the second current I2 and smaller than the absolute value of the third current I3. The direction of the second current I2 is opposite to the direction of the third current I3. The first resistance Rx1 is lower than the second resistance Rx2 and lower than the third resistance Rx3. For example, a valley-type current-resistance characteristic occurs. The first current I1 may be substantially zero.

[0054] As shown in FIG. 7(b), when the current ic is greater than the threshold current Ith and oscillation occurs, the electrical resistance Rx exhibits a crest and valley characteristic. In this case, too, when the absolute values ​​of the second current I2 and the third current I3 are sufficiently large, the electrical resistance Rx can be considered as a valley-type characteristic. For example, the absolute values ​​of the second current I2 and the third current I3 may be values ​​at which the electrical resistance Rx is saturated when the current ic is sufficiently smaller than the threshold current Ith. In this case, too, the first resistance Rx1 is lower than the second resistance Rx2 and lower than the third resistance Rx3. In contrast, in a general STO, a crest-type characteristic occurs. The valley-type characteristic in the embodiment is considered to be a unique characteristic due to the configuration according to the embodiment.

[0055] Such a unique characteristic may be related to the fact that the first magnetic layer 21 has a positive polarization and the second magnetic layer 22 has a negative polarization. In such a combination, when the absolute value of the recording current Iw is large (i.e., when the absolute value of the magnetic field is large), it is considered that the magnetization directions of the first magnetic layer 21 and the second magnetic layer 22 become closer to being parallel to each other, and the resistance increases. In general STO, both magnetic layers have a positive polarization. When the magnetization directions become closer to being parallel to each other, the resistance decreases.

[0056] FIG. 8 is a schematic view illustrating the characteristics of the magnetic head according to the first embodiment. The horizontal axis of Fig. 8 is time tm. The vertical axis is magnetization Mz (normalized value). Fig. 8 shows an example of magnetization Mz1 of the first magnetic layer 21 and magnetization Mz2 of the second magnetic layer 22. As shown in Fig. 8, magnetization Mz1 and magnetization Mz2 rotate in opposite phases (for example, while maintaining opposite directions).

[0057] An example of the magnetic head and the magnetic recording medium 80 included in the magnetic recording device 210 according to the embodiment will be described below. FIG. 9 is a schematic cross-sectional view illustrating the magnetic head according to the embodiment. As shown in FIG. 9, in a magnetic head according to an embodiment (e.g., magnetic head 110), a first direction D1 from the first magnetic pole 31 to the second magnetic pole 32 may be inclined with respect to the X-axis direction. The first direction D1 corresponds to the stacking direction of the stacked body 20. The X-axis direction is along the medium facing surface 30F. The angle between the first direction D1 and the medium facing surface 30F is defined as angle θ1. The angle θ1 is, for example, not less than 15 degrees and not more than 30 degrees. The angle θ1 may be 0 degrees.

[0058] When the first direction D1 is inclined with respect to the X-axis direction, the thickness of the layer corresponds to the length along the first direction D1. The configuration in which the first direction D1 is inclined with respect to the X-axis direction may be applied to any magnetic head according to the embodiment. For example, the interface between the first magnetic pole 31 and the laminate 20 and the interface between the laminate 20 and the second magnetic pole 32 may be inclined with respect to the X-axis direction.

[0059] An example of the magnetic head and the magnetic recording medium 80 included in the magnetic recording device 210 according to the embodiment will be described below.

[0060] FIG. 10 is a schematic perspective view illustrating the magnetic recording device according to the embodiment. 10, 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.

[0061] The magnetic recording medium 80 includes, for example, a medium substrate 82 and a magnetic recording layer 81 provided on the medium substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording unit 60.

[0062] The reproducing unit 70 includes, for example, a first reproducing magnetic shield 72a, a second reproducing magnetic shield 72b, and a magnetic reproducing element 71. The magnetic reproducing element 71 is provided between the first reproducing magnetic shield 72a and the second reproducing magnetic shield 72b. The magnetic reproducing element 71 can output a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0063] 10, the magnetic recording medium 80 moves relative to the magnetic head 110 in a medium movement direction 85. The magnetic head 110 controls information corresponding to the magnetization 83 of the magnetic recording layer 81 at an arbitrary position. The magnetic head 110 reproduces information corresponding to the magnetization 83 of the magnetic recording layer 81 at an arbitrary position.

[0064] FIG. 11 is a schematic perspective view illustrating a portion of the magnetic recording device according to the embodiment. FIG. 11 illustrates a head slider. The magnetic head 110 is provided on a head slider 159. The head slider 159 includes, for example, Al2O3 / TiC, etc. The head slider 159 moves relative to the magnetic recording medium while floating above or in contact with the magnetic recording medium.

[0065] The head slider 159 has, for example, an air inflow side 159A and an air outflow side 159B. The magnetic head 110 is disposed on a side surface of the air outflow side 159B of the head slider 159. This allows the magnetic head 110 to move relative to the magnetic recording medium while floating above or in contact with the magnetic recording medium.

[0066] FIG. 12 is a schematic perspective view illustrating the magnetic recording device according to the embodiment. As shown in FIG. 12, a rotary actuator is used in the magnetic recording device 150 according to the embodiment. The recording medium disk 180 is mounted on a spindle motor 180M. The recording medium disk 180 is rotated in the direction of the arrow AR by the spindle motor 180M. The spindle motor 180M responds to a control signal from a drive control unit. The magnetic recording device 150 according to the embodiment may include a plurality of recording medium disks 180. The magnetic recording device 150 may include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). For the recording medium 181, for example, a non-volatile memory such as a flash memory is used. For example, the magnetic recording device 150 may be a hybrid HDD (Hard Disk Drive).

[0067] The head slider 159 records and reproduces information to be recorded on the recording medium disk 180. The head slider 159 is provided at the tip of the thin-film suspension 154. Near the tip of the head slider 159, a magnetic head according to the embodiment is provided.

[0068] When the recording medium disk 180 rotates, the pressing pressure by the suspension 154 and the pressure generated at the medium facing surface (ABS) of the head slider 159 are balanced. The distance between the medium facing surface of the head slider 159 and the surface of the recording medium disk 180 is a predetermined flying height. In an embodiment, the head slider 159 may be in contact with the recording medium disk 180. For example, a contact running type may be applied.

[0069] The suspension 154 is connected to one end of an arm 155 (e.g., an actuator arm). The arm 155 has, for example, a bobbin portion. The bobbin portion holds a drive coil. A voice coil motor 156 is provided at the other end of the arm 155. The voice coil motor 156 is a type of linear motor. The voice coil motor 156 includes, for example, a drive coil and a magnetic circuit. The drive coil is wound around the bobbin portion of the arm 155. The magnetic circuit includes a permanent magnet and an opposing yoke. The drive 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 one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0070] Arm 155 is held by a ball bearing. The ball bearings are provided at two locations, above and below bearing portion 157. Arm 155 can rotate and slide by voice coil motor 156. The magnetic head can be moved to any position on recording medium disk 180.

[0071] 13A and 13B are schematic perspective views illustrating a part of the magnetic recording device according to the embodiment. 13A illustrates a partial configuration of the magnetic recording device, and is an enlarged perspective view of a head stack assembly 160. FIG 13B is a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA) 158 which is a part of the head stack assembly 160.

[0072] 13(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 extension direction of the support frame 161 is opposite to the extension direction of the head gimbal assembly 158. The support frame 161 supports a coil 162 of the voice coil motor 156.

[0073] As shown in FIG. 13( b ), the head gimbal assembly 158 has an arm 155 extending from a bearing portion 157 , and a suspension 154 extending from the arm 155 .

[0074] A head slider 159 is provided at the tip of the suspension 154. The head slider 159 is provided with a magnetic head according to the embodiment.

[0075] A magnetic head assembly (head gimbal assembly) 158 according to the embodiment includes a 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.

[0076] The suspension 154 has, for example, lead wires (not shown) for recording and reproducing signals. The suspension 154 may have, for example, lead wires (not shown) for a heater for adjusting the flying height. The suspension 154 may have, for example, lead wires (not shown) for a spin transfer torque oscillator or the like. These lead wires are electrically connected to a plurality of electrodes provided on the magnetic head.

[0077] The magnetic recording device 150 is provided with a signal processing unit 190. The signal processing unit 190 uses a magnetic head to record and reproduce signals on a magnetic recording medium. . Faith The input / output lines of the signal processing unit 190 are connected to, for example, electrode pads of the head gimbal assembly 158, and are electrically connected to the magnetic head.

[0078] The magnetic recording device 150 according to the embodiment includes a magnetic recording medium, a magnetic head according to the embodiment, a movable unit, a position control unit, and a signal processing unit. The movable unit allows the magnetic recording medium and the magnetic head to be relatively moved while being separated from each other or in contact with each other. The position control unit aligns the magnetic head with a predetermined recording position on the magnetic recording medium. The signal processing unit records and reproduces signals on the magnetic recording medium using the magnetic head.

[0079] For example, the magnetic recording medium is a recording medium disk 180. The movable portion includes, for example, a head slider 159. The position control portion includes, for example, a head gimbal assembly 158.

[0080] The embodiment may include the following configurations (e.g., technical solutions). (Configuration 1) A first magnetic pole; A second magnetic pole; a laminate provided between the first magnetic pole and the second magnetic pole; Equipped with The laminate comprises: A first magnetic layer; a second magnetic layer provided between the first magnetic layer and the second magnetic pole; a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer; a second nonmagnetic layer provided between the second magnetic layer and the second magnetic pole; a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer; Including, the first magnetic layer includes a first element including at least one of Fe, Co, and Ni; the second magnetic layer includes the first element and a second element including at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc; the first magnetic layer does not contain the second element, or the concentration of the second element in the first magnetic layer is lower than the concentration of the second element in the second magnetic layer; A magnetic head, wherein a first thickness of the first magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is between 0.25 and 4 times a second thickness of the second magnetic layer along the first direction.

[0081] (Configuration 2) 2. The magnetic head of configuration 1, wherein the first thickness is greater than or equal to 0.33 times the second thickness.

[0082] (Configuration 3) 3. The magnetic head according to claim 1, wherein the third nonmagnetic layer is in contact with the first magnetic pole and the first magnetic layer.

[0083] (Configuration 4) 4. The magnetic head according to any one of configurations 1 to 3, wherein the first nonmagnetic layer is in contact with the first magnetic layer and the second magnetic layer.

[0084] (Configuration 5) 5. The magnetic head according to any one of configurations 1 to 4, wherein the second nonmagnetic layer is in contact with the second magnetic layer and the second magnetic pole.

[0085] (Configuration 6) 2. The magnetic head of claim 1, wherein at least one of the first nonmagnetic layer, the second nonmagnetic layer, and the third nonmagnetic layer contains a third element including at least one selected from the group consisting of Cu, Au, Cu, V, Al, and Ag.

[0086] (Configuration 7) 7. The magnetic head according to any one of configurations 1 to 6, wherein the second thickness is 5 nm or more.

[0087] (Configuration 8) The magnetic head according to any one of configurations 1 to 7, wherein the first thickness is 5 nm or more.

[0088] (Configuration 9) 9. The magnetic head according to any one of configurations 1 to 8, wherein the sum of the first thickness and the second thickness is 15 nm or more.

[0089] (Configuration 10) the first magnetic layer includes a first magnetic region and a second magnetic region, the second magnetic region is between the first magnetic region and the first nonmagnetic layer, 10. The magnetic head according to any one of configurations 1 to 9, wherein the saturation magnetization of the first magnetic region is greater than the saturation magnetization of the second magnetic region.

[0090] (Configuration 11) the first magnetic layer includes a first magnetic region and a second magnetic region, the second magnetic region is between the first magnetic region and the first nonmagnetic layer, 10. The magnetic head according to any one of configurations 1 to 9, wherein the concentration of Fe in the first magnetic region is higher than the concentration of Fe in the second magnetic region.

[0091] (Configuration 12) the second magnetic layer includes a third magnetic region and a fourth magnetic region, the fourth magnetic region is between the third magnetic region and the first nonmagnetic layer, 12. The magnetic head according to any one of configurations 1 to 11, wherein the saturation magnetization of the third magnetic region is greater than the saturation magnetization of the fourth magnetic region.

[0092] (Configuration 13) the second magnetic layer includes a third magnetic region and a fourth magnetic region, the fourth magnetic region is between the third magnetic region and the first nonmagnetic layer, 13. The magnetic head according to any one of configurations 1 to 12, wherein the Fe concentration in the third magnetic region is higher than the Fe concentration in the fourth magnetic region.

[0093] (Configuration 14) The stack further includes a third magnetic layer, the third magnetic layer is provided between the second magnetic layer and the second nonmagnetic layer, the third magnetic layer includes a first element including at least one of Fe, Co, and Ni; A magnetic head described in any one of configurations 1 to 13, wherein the third magnetic layer does not contain the second element, or the concentration of the second element in the third magnetic layer is lower than the concentration of the second element in the second magnetic layer.

[0094] (Configuration 15) 15. The magnetic head according to any one of configurations 1 to 14, wherein the concentration of the second element in the second magnetic layer is 10 atomic % or more and 80 atomic % or less.

[0095] (Configuration 16) 16. The magnetic head according to any one of configurations 1 to 15, wherein a current is supplied to the stack in a direction from the first magnetic layer to the second magnetic layer.

[0096] (Configuration 17) 17. The magnetic head of claim 16, wherein an AC magnetic field is generated from the stack when the current is supplied to the stack.

[0097] (Configuration 18) Further comprising a coil; a recording magnetic field generated from at least one of the first magnetic pole and the second magnetic pole changes in response to a recording current flowing through the coil; an electrical resistance of the stack is a first resistance when the recording current is a first current; the electrical resistance is a second resistance when the recording current is a second current, the electrical resistance is a third resistance when the recording current is a third current, an absolute value of the first current is smaller than an absolute value of the second current and smaller than an absolute value of the third current; a direction of the second current is opposite to a direction of the third current; 18. The magnetic material according to any one of configurations 1 to 17, wherein the first resistance is lower than the second resistance and lower than the third resistance. head .

[0098] (Configuration 19) A magnetic head according to any one of configurations 1 to 16, An electric circuit; Equipped with The electric circuit is capable of supplying an electric current to the laminate; The current has a direction from the first magnetic layer to the second magnetic layer.

[0099] (Configuration 20) When the electric circuit supplies a current to the laminate, 20. The magnetic recording device according to claim 19, wherein an AC magnetic field is generated from the laminate.

[0100] According to the embodiment, it is possible to provide a magnetic head and a magnetic recording device that enable improvement in recording density.

[0101] In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include, for example, variations in the manufacturing process, and may mean substantially vertical and substantially parallel.

[0102] The above describes the embodiments of the present invention with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of each element included in the magnetic head, such as the magnetic pole, the laminate, the magnetic layer, the non-magnetic layer, and the wiring, are included in the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain the same effects by appropriately selecting from the known range.

[0103] Any combination of two or more elements of each embodiment, within the scope of technical feasibility, is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0104] In addition, all magnetic heads and magnetic recording devices that can be implemented by a person skilled in the art by making appropriate design modifications based on the magnetic head and magnetic recording device described above as embodiments of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention.

[0105] In addition, within the scope of the concept of the present invention, a person skilled in the art may think of various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0106] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0107] 20...Laminate, 20D...Electric circuit, 21...First magnetic layer, 21a, 21b...First and second magnetic regions, 22...Second magnetic layer, 22c, 22d...Third and fourth magnetic regions, 23...Third magnetic layer, 30D...Recording circuit, 30F...Medium facing surface, 30c...Coil, 30i...Insulating portion, 31, 32...First and second magnetic poles, 33...Shield, 41-43...First to third non-magnetic layers, 60...Recording portion, 70...Reading portion, 71...Magnetic reading element, 72a, 72b...First and second read magnetic shields, 80...Magnetic recording medium, 81...Magnetic recording layer, 82...Medium substrate, 83...Magnetization, 85...Medium movement direction, θ1...Angle, 110, 111, 112...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...first direction, I1 to I3...first to third currents, Ith...threshold current, Iw...recording current, Mz, Mz1, Mz2...magnetization, OS...oscillation intensity, Rx...electrical resistance, Rx1 to Rx3...first to third resistances, T1, T2...first and second terminals, W1, W2...first and second wiring, ic...current, je...electron current, t1~t3...first to third thicknesses, t41~t43...thickness, ts...sum

Claims

1. A first magnetic pole; A second magnetic pole; a laminate provided between the first magnetic pole and the second magnetic pole; Equipped with The laminate comprises: A first magnetic layer; a second magnetic layer provided between the first magnetic layer and the second magnetic pole; a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer; a second nonmagnetic layer provided between the second magnetic layer and the second magnetic pole; a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer; Including, the first magnetic layer includes a first element including at least one of Fe, Co, and Ni; the second magnetic layer includes at least one of Fe and Ni, and a second element including at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc; the first magnetic layer does not contain the second element, or the concentration of the second element in the first magnetic layer is lower than the concentration of the second element in the second magnetic layer; A magnetic head, wherein a first thickness of the first magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is 0.25 to 4 times a second thickness of the second magnetic layer along the first direction.

2. The magnetic head according to claim 1 , wherein the third nonmagnetic layer is in contact with the first magnetic pole and the first magnetic layer.

3. 3. The magnetic head according to claim 1, wherein the second nonmagnetic layer is in contact with the second magnetic layer and the second magnetic pole.

4. 4. The magnetic head according to claim 1, wherein the concentration of the second element in the second magnetic layer is 10 atomic % or more and 80 atomic % or less.

5. A magnetic head according to any one of claims 1 to 4, An electric circuit; Equipped with The electric circuit is capable of supplying an electric current to the laminate; The current has a direction from the first magnetic layer to the second magnetic layer.

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