Magnetic recording apparatus

Abstract

The present disclosure provides a magnetic recording device capable of improving recording density. According to one embodiment, a magnetic recording apparatus includes a magnetic head and a control unit. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, a coil, a first terminal, and a second terminal. The control unit is configured to perform a first operation. In the first operation, the control unit supplies a recording-time element current to the magnetic element and supplies a recording-time coil current to the coil. The absolute value of the coil current during recording is equal to or less than a first coil current value corresponding to the first peak.

Description

[0001] This application is based on Japanese Patent Application No. 2024-151462 (Filing Date: September 3, 2024) and claims priority thereto. This application incorporates the entire contents of the above application by reference. TECHNICAL FIELD

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

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

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

[0005] Technical Solution for Solving the Problem

[0006] According to an embodiment of the present application, a magnetic recording device includes a magnetic head and a control section. The magnetic head includes a first pole, a second pole, a magnetic element disposed between the first pole and the second pole, a coil, a first terminal, and a second terminal. The first terminal is electrically connected to a portion of the magnetic element, and the second terminal is electrically connected to another portion of the magnetic element. The magnetic element includes a first magnetic layer, a second magnetic layer disposed between the first magnetic layer and the second pole, a first non-magnetic layer disposed between the first magnetic layer and the second magnetic layer, a second non-magnetic layer disposed between the second magnetic layer and the second pole, and a third non-magnetic layer disposed between the first pole and the first magnetic layer. When a first coil current of a first frequency is supplied to the coil and a first current is supplied between the first terminal and the second terminal, a first signal having a first signal strength of a first component of the first frequency is generated between the first terminal and the second terminal. When the first coil current is supplied to the coil and a second current is supplied between the first terminal and the second terminal, a second signal having a second signal strength of a second component of the first frequency is generated between the first terminal and the second terminal. The first current has a first direction from the first magnetic layer toward the second magnetic layer. The second current has a second direction from the second magnetic layer toward the first magnetic layer. A second absolute value of the second current is the same as a first absolute value of the first current. A change in an absolute value of the first coil current includes a first peak and a second peak. A first coil current value of the absolute value of the first coil current corresponds to the first peak. A second coil current value of the absolute value of the first coil current corresponds to the second peak. The first coil current value is larger than the second coil current value. The control section is configured to perform a first operation. In the first operation, the control section is configured to supply a recording-time element current to the magnetic element and a recording-time coil current to the coil. An absolute value of the recording-time coil current is equal to or smaller than the first coil current value.

[0007] According to the magnetic recording device configured as described above, a magnetic recording device capable of improving recording density can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 FIG. 1 is a schematic cross-sectional view illustrating a magnetic recording device according to a first embodiment.

[0009] Figure 2 FIG. 1(a) and Figure 2 FIG. 1(b) are schematic views illustrating a portion of the magnetic recording device according to the first embodiment.

[0010] Figure 3 is a diagram illustrating an operation of the magnetic recording apparatus according to the first embodiment.

[0011] Figure 4 (a) to (c) of FIG. 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment. Figure 4 (c) of FIG. 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment.

[0012] Figure 5 (a) to (c) of FIG. 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment. Figure 5 (c) of FIG. 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment.

[0013] Figure 6 (a) and (b) of FIG. 1 are schematic plan views illustrating the magnetic head according to the first embodiment. Figure 6 (b) of FIG. 1 are schematic plan views illustrating the magnetic head according to the first embodiment.

[0014] Figure 7 is a schematic cross-sectional view illustrating the magnetic head according to the first embodiment.

[0015] Figure 8 is a schematic perspective view illustrating the magnetic recording apparatus according to the first embodiment.

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

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

[0018] Figure 11 (a) and (b) of FIG. 1 are schematic perspective views illustrating a part of the magnetic recording apparatus according to the first embodiment. Figure 11 (b) of FIG. 1 are schematic perspective views illustrating a part of the magnetic recording apparatus according to the first embodiment.

[0019] Reference numeral

[0020] 10D: control section, 20: magnetic element, 20D: element circuit, 21-23: 1st-3rd magnetic layers, 21a, 21b: 1st-2nd magnetic regions, 22c, 22d: 3rd-4th magnetic regions, 30D: recording circuit, 30F: medium facing surface, 30c: coil, 30i: insulating portion, 31, 32: 1st-2nd magnetic poles, 33: shield, 41-43: 1st-3rd non-magnetic layers, 60: recording section, 70: reproducing section, 71: magnetic reproducing element, 72a, 72b: 1st-2nd reproducing magnetic shields, 80: magnetic recording medium, 81: magnetic recording layer, 82: medium substrate, 83: magnetization, 85: medium moving direction, 110-112: 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 section, 210: magnetic recording device, AR, AR1: arrow, D1: 1st direction, Ic1: 1st coil current, Icv1, Icv2: 1st-2nd coil current values, Icw: coil current at recording, Id1, Id2: 1st-2nd currents, Idth: element current value, Idw: element current at recording, SS1-SS3: 1st-3rd signal strengths, Sg1-Sg3: 1st-3rd signals, T1, T2: 1st-2nd terminals, Tf1: period, W1, W2: 1st-2nd wires, f1: 1st frequency, je: electron flow, pk1, pk2: 1st-2nd peaks, t1-t3: 1st-3rd thicknesses, tm: time, t41-t43: thicknesses, θ1: angle DETAILED DESCRIPTION

[0021] Hereinafter, each embodiment of the present application will be described with reference to the drawings.

[0022] The drawings are schematic or conceptual views, and the relationship between the thickness and width of each portion, the ratio of sizes among portions, and the like are not necessarily the same as those in reality. Even in cases where the same portion is represented, the dimensions, ratios, and the like can be different among the drawings.

[0023] In the present application specification and each drawing, the same reference numerals are applied to elements similar to those already described with respect to the drawings already present, and detailed description is appropriately omitted.

[0024] (1st Embodiment)

[0025] Figure 1 is a schematic cross-sectional view illustrating a magnetic recording apparatus according to the first embodiment.

[0026] Figure 2 (a) of FIG. 1 1 and Figure 2 (b) of FIG. 1 1 are schematic views illustrating a part of the magnetic recording apparatus according to the first embodiment.

[0027] Figure 2 (a) of FIG. 1 1 is a cross-sectional view. Figure 2 (b) of FIG. 1 1 is a plan view as viewed in the direction of the arrow AR1 of (a) of FIG. 1 1. Figure 2 (a) of FIG. 1 1 is a plan view as viewed in the direction of the arrow AR1 of (a) of FIG. 1 1.

[0028] Figure 3 is a schematic view illustrating an operation of the magnetic recording apparatus according to the first embodiment.

[0029] Figure 4 (a) to Figure 4 (c) of FIG. 1 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment.

[0030] Figure 5 (a) to Figure 5 (c) of FIG. 1 1 are graphs illustrating characteristics of the magnetic recording apparatus according to the first embodiment.

[0031] As shown in FIG. 21, the magnetic recording apparatus 210 according to the embodiment includes a magnetic head 1 10 and a control section 10D. The magnetic recording apparatus 210 can include a magnetic recording medium 80. In the magnetic recording apparatus 210, at least a recording operation is performed. In the recording operation, the magnetic head 1 10 is used to record information to the magnetic recording medium 80. Figure 1

[0032] The magnetic head 1 10 includes a recording section 60. As described later, the magnetic head 1 10 can also include a reproducing section. The recording section 60 includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20. The magnetic element 20 is disposed between the first magnetic pole 31 and the second magnetic pole 32.

[0033] 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.

[0034] ​The direction from the magnetic recording medium 80 toward the magnetic head 110 is designated as the Z-axis direction. A direction perpendicular to the Z-axis direction is designated as the X-axis direction. A direction perpendicular to both the Z-axis and X-axis directions is designated as the Y-axis direction. The Z-axis direction corresponds, for example, to the height direction. The X-axis direction corresponds, for example, to the downtrack direction. The Y-axis direction corresponds, for example, to the crosstrack direction. Along the downtrack direction, the magnetic recording medium 80 moves relative to the magnetic head 110. A magnetic field (recording magnetic field) generated by the magnetic head 110 is applied to the target position of the magnetic recording medium 80. The magnetization of the target position of the magnetic recording medium 80 is controlled in a direction corresponding to the recording magnetic field. Thus, information is recorded onto the magnetic recording medium 80.

[0035] The direction from the first magnetic pole 31 to the second magnetic pole 32 is designated as the first direction D1. The first direction D1 is substantially along the X-axis direction. In an embodiment, the first direction D1 may also be tilted at a small angle relative to the X-axis direction.

[0036] like Figure 1 As shown, the first magnetic pole 31 includes a dielectric-facing surface 30F. The dielectric-facing surface 30F is, for example, an ABS (Air Bearing Surface). The dielectric-facing surface 30F is, for example, opposite to the magnetic recording medium 80. The dielectric-facing surface 30F is, for example, along the XY plane.

[0037] like Figure 1 As shown, the magnetic head 110 also includes a coil 30c. In this example, a portion of the coil 30c is located 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 located between the shield 33 and the second magnetic pole 32. Another portion of the coil 30c is located 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 guide shield. The magnetic head 110 may also include a side shield (not shown).

[0038] like Figure 1 As shown, the control unit 10D may include a recording circuit 30D and a component circuit 20D. A recording current (coil current Icw during recording) is supplied from the recording circuit 30D to the coil 30c. A recording magnetic field corresponding to the coil current Icw during recording, originating from at least one of the first magnetic pole 31 and the second magnetic pole 32, is applied to the magnetic recording medium 80.

[0039] like Figure 1As shown, the component circuit 20D is electrically connected to the magnetic component 20. In this example, the magnetic component 20 is electrically connected to the first magnetic pole 31 and the second magnetic pole 32. The magnetic head 110 includes, for example, a first terminal T1 and a second terminal T2. The first terminal T1 is electrically connected to a portion of the magnetic component 20. The second terminal T2 is electrically connected to another portion of the magnetic component 20. For example, the first terminal T1 is electrically connected to the magnetic component 20 via a first wiring W1 and the first magnetic pole 31. For example, the second terminal T2 is electrically connected to the magnetic component 20 via a second wiring W2 and the second magnetic pole 32. A recording current Idw is supplied from the component circuit 20D to the magnetic component 20. The recording current Idw is, for example, a direct current.

[0040] like Figure 2 (a) and Figure 2 As shown in (b), the magnetic element 20 includes, for example, 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. Figure 2 (a) and Figure 2 In (b), the insulating part 30i is omitted.

[0041] The second magnetic layer 22 is disposed between the first magnetic layer 21 and the second magnetic pole 32. The first non-magnetic layer 41 is disposed between the first magnetic layer 21 and the second magnetic layer 22. The second non-magnetic layer 42 is disposed between the second magnetic layer 22 and the second magnetic pole 32. The third non-magnetic layer 43 is disposed between the first magnetic pole 31 and the first magnetic layer 21.

[0042] For example, the third non-magnetic layer 43 can be connected to the first magnetic pole 31 and the first magnetic layer 21. The first non-magnetic layer 41 can be connected to the first magnetic layer 21 and the second magnetic layer 22. The second non-magnetic layer 42 can be connected to the second magnetic layer 22 and the second magnetic pole 32.

[0043] like Figure 2 As shown in (b), a recording current Idw is supplied to such a magnetic element 20. The recording current Idw is supplied, for example, from the element circuit 20D described above. Figure 2 As shown in (b), the element current Idw during recording has a direction from the first magnetic layer 21 to the second magnetic layer 22. Figure 2 As shown in (b), the electron flow je accompanying the recording element current Idw has a direction from the second magnetic layer 22 to the first magnetic layer 21. The recording element current Idw has a direction from the first magnetic pole 31 to the second magnetic pole 32. The electron flow je has a direction from the second magnetic pole 32 to the first magnetic pole 31.

[0044] For example, when a magnetic field is applied to the magnetic element 20 from the outside, a recording current Idw exceeding a threshold flows in the magnetic element 20. This generates an alternating magnetic field (e.g., a high-frequency magnetic field) from the magnetic element 20. The alternating magnetic field generated in the magnetic element 20 is applied to the magnetic recording medium 80, assisting in writing to the magnetic recording medium 80. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented. It can be considered that the generation of the alternating magnetic field when a magnetic field is applied to the magnetic element 20 and a recording current Idw exceeding a threshold flows in the magnetic element 20 is caused, for example, by the magnetization oscillation of the magnetic layer contained in the magnetic element 20. The magnetic element 20 functions, for example, as an STO (Spin-Torque Oscillator). The recording magnetic field based on the aforementioned recording coil current Icw can function as a magnetic field applied to the magnetic element 20.

[0045] The following describes an example of the characteristics of such a magnetic element 20.

[0046] Figure 3 An example is given of the test first coil current Ic1 supplied to coil 30c. Figure 3 The horizontal axis represents time tm. The vertical axis represents the first coil current Ic1. The first coil current Ic1 varies with a first frequency f1. The first frequency f1 corresponds to the reciprocal of the period Tf1 of the first coil current Ic1. Figure 3 In this circuit, the first coil current Ic1 varies between "-Ic" and "+Ic". For example, the absolute value of the first coil current Ic1 corresponds to half the amplitude when the first coil current Ic1 is set as a rectangular wave.

[0047] It can be seen that when a first coil current Ic1 is supplied for such a test and a current (e.g., a first current Id1 or a second current Id2) is supplied to the magnetic element 20, the current through the magnetic element 20 undergoes a special change.

[0048] Figure 4 (a) corresponds to the case where the absolute value of the first current Id1 (first absolute value) and the absolute value of the second current Id2 (second absolute value) are 0. Figure 4 (b) corresponds to the case where the first absolute value of the first current Id1 and the second absolute value of the second current Id2 exceed 0 and are less than the element current value Idth. The element current value Idth is, for example, the threshold current, which depends on the configuration of the magnetic element 20, etc. Figure 4 (c) corresponds to the case where the first absolute value of the first current Id1 and the second absolute value of the second current Id2 are above the element current value Idth.

[0049] existFigure 4 (a)~ Figure 4 In (c), the first signal strength SS1 of the first signal Sg1 generated by the first current Id1 when the first current Id1 is supplied to the magnetic element 20 is illustrated. Figure 4 (a)~ Figure 4 In (c), the second signal intensity SS2 of the second signal Sg2 generated by the second current Id2 when the second current Id2 is supplied to the magnetic element 20 is illustrated. The first current Id1 has a first direction from the first magnetic layer 21 to the second magnetic layer 22 (see reference). Figure 2 (b)). The second current Id2 has a second direction from the second magnetic layer 22 to the first magnetic layer 21 (see reference). Figure 2 (b)

[0050] When a first coil current Ic1 with a first frequency f1 is supplied to coil 30c and a first current Id1 is supplied between the first terminal T1 and the second terminal T2 (i.e., magnetic element 20), a first signal Sg1 with a first component of the first frequency f1 and a first signal strength SS1 is generated between the first terminal T1 and the second terminal T2. The first signal Sg1 may be, for example, a voltage signal or an electrical power signal.

[0051] When a first coil current Ic1 with a first frequency f1 is supplied to coil 30c and a second current Id2 is supplied between the first terminal T1 and the second terminal T2 (i.e., magnetic element 20), a second signal Sg2 with a second signal intensity SS2 having a second component with the first frequency f1 is generated between the first terminal T1 and the second terminal T2. The second signal Sg2 may be, for example, a voltage signal or an electrical power signal.

[0052] exist Figure 4 (a)~ Figure 4 In (c), the change in the first signal strength SS1 of the first signal Sg1 when the absolute value of the first coil current Ic1 is changed is illustrated by solid lines. Figure 4 (a)~ Figure 4 In (c), the change in the intensity SS2 of the second signal Sg2 when the absolute value of the first coil current Ic1 is changed is illustrated by dashed lines. Figure 4 (a) and Figure 4 In (b), the dashed line (the second signal Sg2) and the solid line (the first signal Sg1) substantially overlap. Figure 4 In (c), the dashed line (the second signal Sg2) does not overlap with the solid line (the first signal Sg1) for most of the time.

[0053] like Figure 4As shown in (a), when the first absolute value of the first current Id1 is 0, the first signal strength SS1 of the first signal Sg1 increases slowly as the absolute value of the first coil current Ic1 increases. When the second absolute value of the second current Id2 is 0, the second signal strength SS2 of the second signal Sg2 increases slowly as the absolute value of the first coil current Ic1 increases. The second signal strength SS2 is substantially the same as the first signal strength SS1.

[0054] like Figure 4 As shown in (b), when the first absolute value of the first current Id1 exceeds 0 and is less than the element current value Idth (threshold), the first signal strength SS1 of the first signal Sg1 slowly increases with the increase of the absolute value of the first coil current Ic1. When the second absolute value of the second current Id2 exceeds 0 and is less than the element current value Idth (threshold), the second signal strength SS2 of the second signal Sg2 slowly increases with the increase of the absolute value of the first coil current Ic1. The first signal strength SS1 and the second signal strength SS2 are essentially the same.

[0055] For example, it can be assumed that the magnetic element 20, the first wiring W1, the first magnetic pole 31, the second wiring W2, and the second magnetic pole 32 are affected by electromagnetic induction from the first coil current Ic1. Figure 4 (a) and Figure 4 As illustrated in (b), the first signal strength SS1 and the second signal strength SS2 increase as the absolute value of the first coil current Ic1 increases. This phenomenon can be attributed to the increased influence of electromagnetic induction and other factors on the first coil current Ic1 as the absolute value of the first coil current Ic1 increases.

[0056] exist Figure 4 In (b), the characteristics of a third signal Sg3, which is not the first frequency f1 but a second frequency, are illustrated. In this example, the third signal Sg3 is a component of the second frequency that is 1.1 times the first frequency f1. Figure 4 As shown in (b), the intensity of the first signal Sg1, which is the first component of the first current Id1 and the first frequency f1, is higher than the intensity of the third signal Sg3. The intensity of the second signal Sg2, which is the second component of the second current Id2 and the first frequency f1, is higher than the intensity of the third signal Sg3.

[0057] Figure 4 The characteristics in (b) show that the first current Id1 and the second current Id2 supplied to the element are affected by the first coil current Ic1. Figure 4 In (b), it can be considered that the effect of the first coil current Ic1 is the electromagnetic effect caused by the first coil current Ic1 that varies with the first frequency f1.

[0058] like Figure 4 As shown in (c), when the first absolute value of the first current Id1 is greater than or equal to the element current value Idth (threshold), the first signal strength SS1 of the first signal Sg1 is different from the second signal strength SS2 of the second signal Sg2. This phenomenon can be attributed to the change in the magnetization state of the magnetic layer contained in the magnetic element 20 due to the influence of the magnetic field based on the first coil current Ic1 and the current flowing in the magnetic element 20 above the threshold.

[0059] like Figure 5 As shown in (c), when the absolute value of the first coil current Ic1 is small, the first signal strength SS1 of the first signal Sg1 is substantially the same as the second signal strength SS2 of the second signal Sg2.

[0060] When the absolute value of the first coil current Ic1 becomes greater than or equal to the second coil current value Icv2, the first signal strength SS1 of the first signal Sg1 is different from the second signal strength SS2 of the second signal Sg2.

[0061] The following explains the time accumulation of the first signal intensity SS1 of the first component of the first frequency f1 of the first signal Sg1 and the time accumulation of the second signal intensity SS2 of the second component of the first frequency f1 of the second signal Sg2.

[0062] Figure 5 (a)~ Figure 5 Example (c) illustrates the difference ΔS1 when the absolute value of the first coil current Ic1 is changed. The difference ΔS1 is the time accumulation of the first signal strength SS1 of the first component of the first frequency f1 of the first signal Sg1 and the time accumulation of the second signal strength SS2 of the second component of the first frequency f1 of the second signal Sg2.

[0063] like Figure 5 As shown in (a), when the first absolute value of the first current Id1 and the second absolute value of the second current Id2 are 0, the difference ΔS1 is essentially 0.

[0064] like Figure 5 As shown in (b), when the first absolute value of the first current Id1 and the second absolute value of the second current Id2 exceed 0 and are less than the element current value Idth (threshold), the difference ΔS1 is also essentially 0.

[0065] Figure 4 (c) corresponds to the case where the first absolute value of the first current Id1 and the second absolute value of the second current Id2 are above the element current value Idth (threshold). When the absolute value of the first coil current Ic1 changes, the change in difference ΔS1 includes peaks (e.g., the first peak pk1 and the second peak pk2).

[0066] Thus, when the absolute value of the first coil current Ic1 changes, the change in the absolute value of the difference ΔS1 between the time accumulation of the first signal strength SS1 and the time accumulation of the second signal strength SS2 includes the first peak pk1 and the second peak pk2. The absolute value of the first coil current Ic1 corresponds to the first coil current value Icv1, which is the first coil current value Icv1. When the absolute value of the first coil current Ic1 is equal to the first coil current value Icv1, the difference ΔS1 becomes the first peak pk1. The absolute value of the first coil current Ic1 corresponds to the second coil current value Icv2, which is the second coil current value Icv2. When the absolute value of the first coil current Ic1 is equal to the second coil current value Icv2, the difference ΔS1 becomes the second peak pk2. The first coil current value Icv1 is greater than the second coil current value Icv2.

[0067] For example, when the first absolute value of the first current Id1 is greater than or equal to the element current value Idth (threshold), and the absolute value of the first coil current Ic1 is greater than or equal to the second coil current value Icv2, the magnetic element 20 is influenced by both the first coil current Ic1 and the first current Id1. For example, the magnetic field based on the first coil current Ic1 and the influence of the first current Id1 supplied to the magnetic element 20 effectively act on the magnetic element 20. For example, an alternating magnetic field is effectively generated from the magnetic element 20. For example, magnetized oscillations are obtained efficiently.

[0068] When the absolute value of the first current Id1 is greater than or equal to the element current value Idth (threshold) and the absolute value of the first coil current Ic1 exceeds the first coil current value Icv1, it can be considered that the magnetic element 20 is excessively affected by the first coil current Ic1. For example, the efficiency of generating an alternating magnetic field from the magnetic element 20 decreases.

[0069] The recording coil current Icw during the recording action can be based on Figure 5 (c) or Figure 5 The characteristics illustrated in (c) are used to set them.

[0070] For example, the control unit 10D is configured to perform a first operation. The first operation corresponds to a recording operation. In the first operation, the control unit 10D is configured to supply a recording element current Idw to the magnetic element 20 and a recording coil current Icw to the coil 30c. The absolute value of the recording coil current Icw is less than or equal to a first coil current value Icv1. Therefore, for example, it is possible to suppress the decrease in efficiency of generating an alternating magnetic field from the magnetic element 20. A highly efficient recording operation can be performed. Thus, a magnetic recording apparatus that can improve recording density can be provided.

[0071] During recording, the component current Idw has the first direction described above. The absolute value of the component current Idw during recording is greater than or equal to the component current value Idth (threshold). The first absolute value of the first current Id1 and the second absolute value of the second current Id2, referenced in the first operation, are greater than or equal to the component current value Idth (threshold).

[0072] In this implementation, the absolute value of the coil current Icw during recording can be greater than or equal to the second coil current value Icv2. The magnetic field based on the first coil current Ic1 and the influence of the first current Id1 supplied to the magnetic element 20 act more effectively on the magnetic element 20. For example, an alternating magnetic field is generated more effectively from the magnetic element 20.

[0073] like Figure 4 As shown in (c), the first coil current value Icv1 is substantially three times the second coil current value Icv2. In an embodiment, the first coil current value Icv1 can be more than 2.5 times and less than 3.5 times the second coil current value Icv2.

[0074] The first peak pk1 can be higher than the second peak pk2. The first peak pk1 can be more prominent than the second peak pk2.

[0075] The changes in the absolute values ​​of the first peak pk1 and the second peak pk2 relative to the first coil current Ic1 can be asymmetrical. In this example, the steepness of the change in the first peak pk1 when the absolute value of the first coil current Ic1 changes within a range less than the first coil current value Icv1 is higher than the steepness of the change in the first peak pk1 when the absolute value of the first coil current Ic1 changes within a range exceeding the first coil current value Icv1. Similarly, the steepness of the change in the second peak pk2 when the absolute value of the first coil current Ic1 changes within a range less than the second coil current value Icv2 is higher than the steepness of the change in the second peak pk2 when the absolute value of the first coil current Ic1 changes within a range exceeding the second coil current value Icv2.

[0076] As already explained, when the first absolute value of the first current Id1 and the second absolute value of the second current Id2 are less than the element current value Idth (threshold), the change in the absolute value of the difference ΔS1 between the time accumulation of the first signal strength SS1 and the time accumulation of the second signal strength SS2 when the absolute value of the first coil current Ic1 changes can substantially exclude the first peak pk1 and the second peak pk2.

[0077] For example, such as regarding Figure 2As explained in (b), when a first coil current Ic1 with a first frequency f1 is supplied to coil 30c and a first current Id1 is supplied between the first terminal T1 and the second terminal T2 (i.e., magnetic element 20), a third signal Sg3 with a third component of a second frequency and a third signal strength SS3 can be generated between the first terminal T1 and the second terminal T2. The time accumulation of the first signal strength SS1 when the absolute value of the first coil current Ic1 is the second coil current value Icv2 can be greater than the time accumulation of the third signal strength SS3 when the absolute value of the first coil current Ic1 is the second coil current value Icv2. The second frequency can be, for example, 1.1 times the first frequency f1. A high signal strength can be obtained at the first frequency f1 of the first coil current Ic1. The third signal Sg3 can be, for example, a voltage signal or an electrical power signal.

[0078] For example, the time accumulation of the first signal strength SS1 when the absolute value of the first coil current Ic1 is the same as the first coil current value Icv1 can be greater than the time accumulation of the third signal strength SS3 when the absolute value of the first coil current Ic1 is the same as the first coil current value Icv1.

[0079] For example, when the absolute value of the first coil current Ic1 changes, the change in the difference between the time accumulation of the first signal strength SS1 and the time accumulation of the third signal strength SS3 can also contain a peak. For example, when the absolute value of the first coil current Ic1 changes, the change in the difference between the time accumulation of the first signal strength SS1 and the time accumulation of the third signal strength SS3, which displays a peak in the absolute value of the first coil current Ic1, can be substantially the same as the change in the difference ΔS1, which displays a peak in the absolute value of the first coil current Ic1.

[0080] In the embodiment, the first frequency f1 of the first coil current Ic1 can be, for example, 1 MHz or more and 4 GHz or less. The frequency of the AC magnetic field based on the oscillation of the magnetic element 20 can be, for example, 5 GHz or more and 50 GHz or less. For example, the first frequency f1 can be lower than the frequency of the AC magnetic field based on the oscillation.

[0081] In this embodiment, at least any one of the first nonmagnetic layer 41, the second nonmagnetic layer 42, and the third nonmagnetic layer 43 contains a third element. The third element may include, for example, at least one selected from Cu, Au, Cr, V, Al, and Ag. In nonmagnetic layers containing such materials, for example, high spin transmittance can be obtained. For example, high oscillation intensity can be obtained.

[0082] At least one of the second nonmagnetic layer 42 and the third nonmagnetic layer 43 may also contain a fourth element. The fourth element may include, for example, at least one selected from Ru, Ir, Ta, Rh, Pd, Pt, and W. In a nonmagnetic layer containing such a material, for example, low spin transmittance can be obtained. For example, stable oscillations are easily obtained. At least one of the second nonmagnetic layer 42 and the third nonmagnetic layer 43 may also contain the aforementioned third and fourth elements.

[0083] In this embodiment, the first magnetic layer 21 contains a first element. The first element includes at least one of Fe, Co, and Ni.

[0084] The second magnetic layer 22 contains a first element and a second element. The second element contains at least one selected from Cr, V, Mn, Ti, and Sc. The first magnetic layer 21 does not contain 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.

[0085] For example, the concentration of the second element described above in the second magnetic layer 22 is 10 atomic percent or more and 80 atomic percent or less. The second magnetic layer 22 containing such a material has, for example, negative spin polarization. On the other hand, the first magnetic layer 21 has, for example, positive spin polarization.

[0086] Through the first magnetic layer 21 and the second magnetic layer 22, a high-intensity alternating magnetic field can be stably obtained.

[0087] In the magnetic head 110, the first magnetic layer 21 and the second magnetic layer 22 function as oscillation layers, for example. 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.

[0088] like Figure 6 As shown in (b), the thickness of the first magnetic layer 21 along the first direction D1 (from the first magnetic pole 31 to the second magnetic pole 32) is defined as the first thickness t1. The thickness of the second magnetic layer 22 along the first direction D1 is defined as the second thickness t2. In an embodiment, for example, the first thickness t1 and the second thickness t2 can be the same. Thus, as described later, oscillation can be easily obtained.

[0089] The thickness of the first nonmagnetic layer 41 along the first direction D1 is defined as thickness t41. The thickness of the second nonmagnetic layer 42 along the first direction D1 is defined as thickness t42. The thickness of the third nonmagnetic layer 43 along the first direction D1 is defined as thickness t43. These thicknesses are, for example, 0.5 nm or more and 6 nm or less. Because these thicknesses are 0.5 nm or more, stable oscillations become easier. Because these thicknesses are 6 nm or less, for example, spin transmittance easily becomes high. For example, high oscillation intensity is easily obtained.

[0090] Let the ratio of the first thickness t1 to the second thickness t2 (i.e., t1 / t2) be defined as the thickness ratio R1. A high oscillation intensity can be obtained when the thickness ratio R1 is close to 1. For example, stable oscillation can be obtained when the thickness ratio R1 is above 0.25 and below 4. A thickness ratio R1 above 0.33 can also yield an even higher oscillation intensity. A thickness ratio R1 below 3 can also yield an even higher oscillation intensity.

[0091] In this embodiment, the first thickness t1 is preferably 0.25 times or more and 4 times or less than the second thickness t2. This allows for a high oscillation intensity and stable oscillation. Alternatively, the first thickness t1 can be 0.33 times or more and 3 times or less than the second thickness t2. This allows for an even higher oscillation intensity and more stable oscillation. According to this embodiment, stable MAMR can be implemented. A magnetic head that increases recording density can be provided.

[0092] The first thickness t1 is preferably 5 nm or more. The first thickness t1 can, for example, be 20 nm or less. For example, this can shorten the distance (e.g., the recording gap) between the first magnetic pole 31 and the second magnetic pole 32. For example, a high recording density can be easily obtained. The second thickness t2 is preferably 5 nm or more. The second thickness t2 can be 20 nm or less. For example, this can shorten the recording gap. For example, a high recording density can be easily obtained. The sum of the first thickness t1 and the second thickness t2, ts, is preferably 15 nm or more. This allows for a high oscillation intensity. ts can be 40 nm or less. For example, this can shorten the recording gap. For example, a high recording density can be easily obtained.

[0093] Figure 6 (a) and Figure 6 (b) is a schematic plan view illustrating the magnetic head according to the first embodiment.

[0094] like Figure 6As shown in (a), the magnetic head 111 according to the embodiment includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20. In the magnetic head 111, the magnetic element 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 either the first magnetic layer 21 or the second magnetic layer 22 includes multiple regions. Other than this, the configuration of the magnetic head 111 can be the same as that of the magnetic head 110.

[0095] 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 located 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 greater than the saturation magnetization of the second magnetic region 21b. Thus, for example, it becomes easier to obtain stable oscillations.

[0096] For example, the saturation magnetization of the first magnetic region 21a is more than 1.2 times that of the saturation magnetization of the second magnetic region 21b. This makes it easy to obtain stable oscillations. Alternatively, the saturation magnetization of the first magnetic region 21a can be less than 3 times that of the saturation magnetization of the second magnetic region 21b. This also makes it easy to obtain stable oscillations.

[0097] For example, the Fe concentration in the first magnetic region 21a is higher than the Fe concentration in the second magnetic region 21b. For example, the saturation magnetization of the first magnetic region 21a is more likely to be greater than that of the second magnetic region 21b. For example, the Ni concentration in the first magnetic region 21a is lower than that in the second magnetic region 21b. Therefore, for example, the saturation magnetization of the first magnetic region 21a is more likely to be greater than that of the second magnetic region 21b. The boundary between the first magnetic region 21a and the second magnetic region 21b may be distinct or indistinct.

[0098] 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 located 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 greater than the saturation magnetization of the fourth magnetic region 22d. Thus, for example, it becomes easier to obtain stable oscillations.

[0099] For example, the saturation magnetization of the third magnetic region 22c is more than 1.2 times that of the saturation magnetization of the fourth magnetic region 22d. Therefore, stable oscillations are easily obtained. Alternatively, the saturation magnetization of the third magnetic region 22c can be less than 3 times that of the saturation magnetization of the fourth magnetic region 22d. Therefore, stable oscillations are easily obtained.

[0100] For example, the Fe concentration in the third magnetic region 22c is higher than the Fe concentration in the fourth magnetic region 22d. Therefore, for example, the saturation magnetization of the third magnetic region 22c is more 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 in the fourth magnetic region 22d. Therefore, for example, the saturation magnetization of the third magnetic region 22c is more 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 distinct or indistinct.

[0101] like Figure 7 As shown in (b), the magnetic head 112 according to the embodiment includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20. In the magnetic head 112, the magnetic element 20 includes a third magnetic layer 23 in addition to the first magnetic layer 21, the second magnetic layer 22, the first non-magnetic layer 41, the second non-magnetic layer 42, and the third non-magnetic layer 43. The other components in the magnetic head 112 can be the same as those in the magnetic head 110 or the magnetic head 111.

[0102] A third magnetic layer 23 is disposed between the second magnetic layer 22 and the second non-magnetic layer 42. The third magnetic layer 23 contains a first element, which includes at least one of Fe, Co, and Ni. The third magnetic layer 23 does not contain 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 explained, the second element includes at least one selected from Cr, V, Mn, Ti, and Sc.

[0103] For example, the saturation magnetization of the third magnetic layer 23 is higher than that of the second magnetic layer 22. Therefore, for example, it becomes easier to obtain stable oscillations. The boundary between the third magnetic layer 23 and the first magnetic layer 21 may or may not be distinct. The third magnetic layer 23 may be continuous with the second magnetic layer 22.

[0104] In the magnetic head 112, the first thickness t1 of the first magnetic layer 21 is, for example, more than 0.8 times and less than 1.25 times the sum of the third thickness t3 of the third magnetic layer 23 along the first direction D1 (from the first magnetic pole 31 to the second magnetic pole 32) and the second thickness t2 of the second magnetic layer 22. For example, high oscillation intensity can be obtained. Stable oscillation can be obtained.

[0105] Hereinafter, examples of the magnetic head and magnetic recording medium 80 included in the magnetic recording apparatus 210 according to the embodiments will be described.

[0106] Figure 7 This is a schematic cross-sectional view illustrating the magnetic head according to an illustrative embodiment.

[0107] likeFigure 8 As shown, in the magnetic head (e.g., magnetic head 110) according to the embodiment, the first direction D1 from the first magnetic pole 31 to the second magnetic pole 32 may also be tilted relative to the X-axis direction. The first direction D1 corresponds to the stacking direction of the magnetic element 20. The X-axis direction is along the dielectric opposing surface 30F. The angle between the first direction D1 and the dielectric opposing surface 30F is set as angle θ1. Angle θ1 is, for example, 15 degrees or more and 30 degrees or less. Angle θ1 may also be 0 degrees.

[0108] 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. This tilting configuration of the first direction D1 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 magnetic element 20, and the interface between the magnetic element 20 and the second magnetic pole 32, can also be tilted relative to the X-axis direction.

[0109] Hereinafter, examples of the magnetic head and magnetic recording medium 80 included in the magnetic recording apparatus 210 according to the embodiments will be described.

[0110] Figure 8 This is a schematic perspective view illustrating a magnetic recording apparatus according to an exemplary embodiment.

[0111] like Figure 8 As shown, the magnetic head (e.g., magnetic head 110) involved in the embodiment is used together with the magnetic recording medium 80. In this example, the magnetic head 110 includes a recording section 60 and a playback section 70. Information is recorded on the magnetic recording medium 80 through the recording section 60 of the magnetic head 110. The information recorded on the magnetic recording medium 80 is reproduced through the playback section 70.

[0112] The magnetic recording medium 80 includes, for example, a medium substrate 82 and a magnetic recording layer 81 disposed on the medium substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording unit 60.

[0113] 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 is capable of outputting a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0114] like Figure 9 As shown, the magnetic recording medium 80 moves relative to the magnetic head 110 in the medium movement direction 85. The magnetic head 110 controls the information corresponding to the magnetization 83 of the magnetic recording layer 81 at any position. The magnetic head 110 reproduces the information corresponding to the magnetization 83 of the magnetic recording layer 81 at any position.

[0115] Figure 9This is a schematic perspective view illustrating a portion of a magnetic recording apparatus according to an exemplary embodiment.

[0116] Figure 10 An example of a head slider is shown.

[0117] The magnetic head 110 is disposed on the head slider 159. The head slider 159 may contain, for example, Al2O3 / TiC. The head slider 159 floats above or in contact with the magnetic recording medium while moving relative to the magnetic recording medium.

[0118] The head slider 159 has, for example, an air inlet side 159A and an air outlet side 159B. The magnetic head 110 is disposed on the side of the air outlet side 159B of the head slider 159. Thus, the magnetic head 110 moves relative to the magnetic recording medium while floating above or in contact with it.

[0119] Figure 10 This is a schematic perspective view illustrating a magnetic recording apparatus according to an exemplary embodiment.

[0120] like Figure 11 As shown, in the magnetic recording apparatus 150 according to this embodiment, a rotary actuator is used. A recording media disk 180 is mounted on a spindle motor 180M. The recording media disk 180 rotates in the direction of arrow AR via the spindle motor 180M. The spindle motor 180M responds to control signals from a drive unit control unit. The magnetic recording apparatus 150 according to this embodiment may also include multiple recording media disks 180. The magnetic recording apparatus 150 may also include a recording medium 181. The recording medium 181 may be, for example, an SSD (Solid State Drive). The recording medium 181 may use, for example, non-volatile memory such as flash memory. For example, the magnetic recording apparatus 150 may also be a hybrid HDD (Hard Disk Drive).

[0121] The head slider 159 records and reproduces information recorded on the recording medium disk 180. The head slider 159 is disposed at the front end of the thin-film suspension 154. The magnetic head according to the embodiment is disposed near the front end of the head slider 159.

[0122] When the recording media disk 180 rotates, the pressing pressure generated by the suspension 154 balances the pressure generated on the media-facing surface (ABS) of the head slider 159. The distance between the media-facing surface of the head slider 159 and the surface of the recording media disk 180 is a predetermined upward displacement. In an embodiment, the head slider 159 may also contact the recording media disk 180. For example, a contact-moving type may also be used.

[0123] Suspension 154 is connected to one end of arm 155 (e.g., actuator arm). Arm 155 has, for example, a winding frame portion. The winding frame portion holds a drive coil. A voice coil motor 156 is provided at the other end of arm 155. Voice coil motor 156 is a type of linear motor. Voice coil motor 156 includes, for example, a drive coil and a magnetic circuit. The drive coil is wound around the winding frame portion of arm 155. The magnetic circuit includes a permanent magnet and a counter-rotating yoke. The drive coil is provided between the permanent magnet and the counter-rotating yoke. Suspension 154 has one end and another end. A magnetic head is provided at one end of suspension 154. Arm 155 is connected to the other end of suspension 154.

[0124] The arm 155 is held in place by ball bearings. Ball bearings are located at the upper and lower parts of the bearing section 157. The arm 155 can rotate and slide via the voice coil motor 156. The magnetic head can be moved to any position on the recording media disk 180.

[0125] Figure 11 (a) and Figure 11 (b) is a schematic perspective view illustrating a portion of the magnetic recording apparatus according to an exemplary embodiment.

[0126] Figure 11 (a) illustrates a portion of the configuration of a magnetic recording apparatus and is an enlarged perspective view of the head stack assembly 160.

[0127] Figure 11 (b) is a perspective view illustrating a head assembly (head gimbal assembly: HGA) 158 as part of a head stack assembly 160.

[0128] like Figure 11 As shown in (a), the head stack assembly 160 includes a bearing portion 157, a head universal joint assembly 158, and a support frame 161. The head universal joint assembly 158 extends from the bearing portion 157. The support frame 161 extends from the bearing portion 157. The extending direction of the support frame 161 is opposite to the extending direction of the head universal joint assembly 158. The support frame 161 supports the coil 162 of the voice coil motor 156.

[0129] like ​ As shown in (b), the head universal joint assembly 158 has an arm 155 extending from the bearing portion 157 and a suspension 154 extending from the arm 155.

[0130] A head slider 159 is provided at the front end of the suspension 154. The magnetic head according to the embodiment is provided on the head slider 159.

[0131] The head assembly (head universal joint assembly) 158 according to the embodiment includes the head according to the embodiment, a head slider 159 on which the head is provided, a suspension 154, and an arm 155. The head slider 159 is disposed at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0132] Suspension 154 may have, for example, leads (not shown) for recording and reproducing signals. Suspension 154 may also have, for example, leads (not shown) for a heater for adjusting buoyancy. Suspension 154 may also have, for example, leads (not shown) for a spin-torque oscillator, etc. These leads are electrically connected to multiple electrodes disposed on the magnetic head.

[0133] In the magnetic recording apparatus 150, a signal processing unit 190 is provided. The signal processing unit 190 uses a magnetic head to record and reproduce signals from the magnetic recording medium. The input and output lines of the signal processing unit 190 are electrically connected to the magnetic head, for example, by connecting to the electrode pads of the head gimbal assembly 158.

[0134] The magnetic recording apparatus 150 according to the embodiment includes a magnetic recording medium, a magnetic head according to the embodiment, a movable part, a position control unit, and a signal processing unit. The movable part enables relative movement between the magnetic recording medium and the magnetic head in a separated or contacted state. 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 the signal of the magnetic recording medium using the magnetic head.

[0135] For example, a recording media disk 180 is used as the magnetic recording medium described above. The movable part described above includes, for example, a head slider 159. The position control part described above includes, for example, a head universal joint assembly 158.

[0136] The implementation methods may include the following technical solutions.

[0137] (Technical Solution 1)

[0138] A magnetic recording device comprising a magnetic head and a control unit,

[0139] The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element disposed between the first magnetic pole and the second magnetic pole, a first terminal, a second terminal, and a coil.

[0140] The first terminal is electrically connected to a portion of the magnetic element.

[0141] The second terminal is electrically connected to another part of the magnetic element.

[0142] The magnetic element includes:

[0143] First magnetic layer;

[0144] A second magnetic layer is disposed between the first magnetic layer and the second magnetic pole;

[0145] A first non-magnetic layer is disposed between the first magnetic layer and the second magnetic layer;

[0146] A second non-magnetic layer is disposed between the second magnetic layer and the second magnetic pole; and

[0147] A third non-magnetic layer is disposed between the first magnetic pole and the first magnetic layer.

[0148] When a first coil current of the first frequency is supplied to the coil and a first current is supplied between the first terminal and the second terminal, a first signal with a first signal strength having a first component of the first frequency is generated between the first terminal and the second terminal.

[0149] When the first coil current is supplied to the coil and the second current is supplied between the first terminal and the second terminal, a second signal with a second signal strength having a second component of the first frequency is generated between the first terminal and the second terminal.

[0150] The first current has a first direction from the first magnetic layer to the second magnetic layer.

[0151] The second current has a second direction from the second magnetic layer to the first magnetic layer.

[0152] The second absolute value of the second current is the same as the first absolute value of the first current.

[0153] The change in the absolute value of the difference between the time-cumulative sum of the first signal strength and the time-cumulative sum of the second signal strength when the absolute value of the first coil current changes includes the first peak and the second peak.

[0154] The absolute value of the first coil current corresponds to the first peak.

[0155] The absolute value of the first coil current corresponds to the second coil current value, which is related to the second peak.

[0156] The current value of the first coil is greater than the current value of the second coil.

[0157] The control unit is configured to perform the first action.

[0158] In the first operation, the control unit is configured to supply a recording current to the magnetic element and a recording coil current to the coil.

[0159] The absolute value of the coil current at the time of recording is less than or equal to the value of the first coil current.

[0160] (Technical Solution 2)

[0161] According to the magnetic recording device described in technical solution 1

[0162] The absolute value of the coil current at the time of recording is greater than or equal to the value of the second coil current.

[0163] (Technical Solution 3)

[0164] The magnetic recording device according to technical solution 1 or 2

[0165] The current value of the first coil is more than 2.5 times and less than 3.5 times the current value of the second coil.

[0166] (Technical Solution 4)

[0167] The magnetic recording device according to any one of technical solutions 1 to 3,

[0168] The first absolute value and the second absolute value are greater than or equal to the component current value.

[0169] The absolute value of the component current at the time of recording is greater than or equal to the component current value.

[0170] The element current has the first direction during recording.

[0171] (Technical Solution 5)

[0172] According to the magnetic recording device described in technical solution 4

[0173] When the first absolute value and the second absolute value are less than the element current value,

[0174] The change in the absolute value of the difference between the time accumulation of the first signal strength and the time accumulation of the second signal strength when the absolute value of the first coil current changes substantially does not include the first peak and the second peak.

[0175] (Technical Solution 6)

[0176] The magnetic recording device according to any one of technical solutions 1 to 5,

[0177] When the first coil current is supplied to the coil and the first current is supplied between the first terminal and the second terminal, a third signal with a third signal strength having a second frequency is generated between the first terminal and the second terminal.

[0178] The cumulative time of the first signal strength when the absolute value of the first coil current is the value of the second coil current is greater than the cumulative time of the third signal strength when the absolute value of the first coil current is the value of the second coil current.

[0179] (Technical Solution 7)

[0180] According to the magnetic recording device described in technical solution 6

[0181] The time accumulation of the first signal strength when the absolute value of the first coil current is the first coil current value is greater than the time accumulation of the third signal strength when the absolute value of the first coil current is the first coil current value.

[0182] (Technical Solution 8)

[0183] The magnetic recording device according to any one of technical solutions 1 to 7,

[0184] The first magnetic layer contains a first element, which includes at least one of Fe, Co, and Ni.

[0185] The second magnetic layer contains the first element and the second element, wherein the second element comprises at least one selected from Cr, V, Mn, Ti, and Sc.

[0186] 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.

[0187] (Technical Solution 9)

[0188] According to the magnetic recording device described in technical solution 8

[0189] The magnetic element also includes a third magnetic layer.

[0190] The third magnetic layer is disposed between the second magnetic layer and the second non-magnetic layer.

[0191] The third magnetic layer contains at least one of Fe, Co, and Ni.

[0192] 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.

[0193] (Technical Solution 10)

[0194] The magnetic recording device according to technical solution 8 or 9

[0195] The concentration of the second element in the second magnetic layer is 10 atomic% or more and 80 atomic% or less.

[0196] (Technical Solution 11)

[0197] The magnetic recording device according to any one of technical solutions 1 to 10,

[0198] The first thickness of the first magnetic layer along the first direction from the first magnetic pole to the second magnetic pole is more than 0.25 times and less than 4 times the second thickness of the second magnetic layer along the first direction.

[0199] (Technical Solution 12)

[0200] The magnetic recording device according to any one of technical solutions 1 to 11,

[0201] The first magnetic layer includes a first magnetic region and a second magnetic region.

[0202] The second magnetic region is located between the first magnetic region and the first non-magnetic layer.

[0203] The saturation magnetization of the first magnetic region is greater than that of the second magnetic region.

[0204] (Technical Solution 13)

[0205] The magnetic recording device according to any one of technical solutions 1 to 12,

[0206] The second magnetic layer includes a third magnetic region and a fourth magnetic region.

[0207] The fourth magnetic region is located between the third magnetic region and the first non-magnetic layer.

[0208] The saturation magnetization of the third magnetic region is greater than that of the fourth magnetic region.

[0209] (Technical Solution 14)

[0210] The magnetic recording device according to any one of technical solutions 1 to 13,

[0211] The third non-magnetic layer is in contact with the first magnetic pole and the first magnetic layer.

[0212] (Technical Solution 15)

[0213] The magnetic recording device according to any one of technical solutions 1 to 14,

[0214] The first non-magnetic layer is in contact with the first magnetic layer and the second magnetic layer.

[0215] (Technical Solution 16)

[0216] The magnetic recording device according to any one of technical solutions 1 to 8,

[0217] The second non-magnetic layer is connected to the second magnetic layer and the second magnetic pole.

[0218] (Technical Solution 17)

[0219] The magnetic recording apparatus according to any one of technical solutions 1 to 16,

[0220] At least one of the first nonmagnetic layer, the second nonmagnetic layer, and the third nonmagnetic layer contains a third element, which includes at least one selected from Cu, Au, Cr, V, Al, and Ag.

[0221] (Technical Solution 18)

[0222] The magnetic recording device according to any one of technical solutions 1 to 11,

[0223] The first magnetic layer includes a first magnetic region and a second magnetic region.

[0224] The second magnetic region is located between the first magnetic region and the first non-magnetic layer.

[0225] The Fe concentration in the first magnetic region is higher than the Fe concentration in the second magnetic region.

[0226] (Technical Solution 19)

[0227] The magnetic recording device according to any one of technical solutions 1 to 12,

[0228] The second magnetic layer includes a third magnetic region and a fourth magnetic region.

[0229] The fourth magnetic region is located between the third magnetic region and the first non-magnetic layer.

[0230] The Fe concentration in the third magnetic region is higher than the Fe concentration in the fourth magnetic region.

[0231] (Technical Solution 20)

[0232] The magnetic recording apparatus according to any one of technical solutions 1 to 19,

[0233] In the first action, an alternating magnetic field is generated from the magnetic element.

[0234] According to the embodiments, a magnetic recording device that can improve recording density can be provided.

[0235] In this application specification, "perpendicular" and "parallel" are not only strictly perpendicular and strictly parallel, but also include deviations in manufacturing processes, etc., as long as they are substantially perpendicular and substantially parallel.

[0236] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, any specific configuration of the elements included in the magnetic recording apparatus, such as the magnetic head, magnetic poles, magnetic elements, magnetic layer, non-magnetic layer, wiring, magnetic recording medium, and control unit, is included within the scope of the present invention as long as those skilled in the art can appropriately select from the known scope to similarly implement the present invention and obtain the same effects.

[0237] Any technical solution obtained by combining any two or more elements of various specific examples within a technically feasible range is included within the scope of this invention as long as it contains the spirit of this invention.

[0238] Furthermore, all magnetic recording devices that can be implemented by appropriate design modifications by those skilled in the art based on the magnetic recording apparatus described above as an embodiment of the present invention are also within the scope of the present invention, as long as they contain the spirit of the present invention.

[0239] Furthermore, within the scope of the present invention, various modifications and alterations can be conceived by those skilled in the art, and such modifications and alterations are also understood to fall within the scope of the present invention.

[0240] Several embodiments of the present invention have been described, but these embodiments are provided by way of example and are not intended to limit the scope of the invention. These new embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and / or variations thereof are included within the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A magnetic recording apparatus comprising a magnetic head and a control section, the magnetic head including a first magnetic pole, a second magnetic pole, a magnetic element disposed between the first magnetic pole and the second magnetic pole, a coil, a first terminal, and a second terminal, the first terminal being electrically connected to a portion of the magnetic element, the second terminal being electrically connected to another portion of the magnetic element, the magnetic element including: a first magnetic layer; a second magnetic layer disposed between the first magnetic layer and the second magnetic pole; a first non-magnetic layer disposed between the first magnetic layer and the second magnetic layer; a second non-magnetic layer disposed between the second magnetic layer and the second magnetic pole; and a third non-magnetic layer disposed between the first magnetic pole and the first magnetic layer, when a first coil current of a first frequency is supplied to the coil and a first current is supplied between the first terminal and the second terminal, a first signal having a first signal strength of a first component of the first frequency is generated between the first terminal and the second terminal, when the first coil current is supplied to the coil and a second current is supplied between the first terminal and the second terminal, a second signal having a second signal strength of a second component of the first frequency is generated between the first terminal and the second terminal, the first current has a first direction from the first magnetic layer toward the second magnetic layer, the second current has a second direction from the second magnetic layer toward the first magnetic layer, a second absolute value of the second current is the same as a first absolute value of the first current, a change in an absolute value of the first coil current includes a first peak and a second peak, a first coil current value of the absolute value of the first coil current corresponds to the first peak, a second coil current value of the absolute value of the first coil current corresponds to the second peak, the first coil current value is larger than the second coil current value, the control section is configured to perform a first operation, in the first operation, the control section is configured to supply a recording-time element current to the magnetic element and a recording-time coil current to the coil, the absolute value of the recording-time coil current is equal to or less than the first coil current value.

2. The magnetic recording apparatus according to claim 1, the absolute value of the recording-time coil current is equal to or more than the second coil current value.

3. The magnetic recording apparatus according to claim 1, the first coil current value is equal to or more than 2.5 times and equal to or less than 3.5 times the second coil current value.

4. The magnetic recording apparatus according to claim 1, the first absolute value and the second absolute value are equal to or more than an element current value, an absolute value of the recording-time element current is equal to or more than the element current value, the recording-time element current has the first direction.

5. The magnetic recording apparatus according to claim 4, in a case where the first absolute value and the second absolute value are less than the element current value, ​ The change in the absolute value of the difference between the time integration of the first signal strength when the absolute value of the first coil current is changed and the time integration of the second signal strength does not substantially include the first peak and the second peak.

6. The magnetic recording device according to claim 1, When the first coil current is supplied to the coil and the first current is supplied between the first terminal and the second terminal, a third signal having a third signal strength of a third component having a second frequency is generated between the first terminal and the second terminal, The time integration of the first signal strength when the absolute value of the first coil current is the second coil current value is larger than the time integration of the third signal strength when the absolute value of the first coil current is the first coil current value.

7. The magnetic recording device according to claim 6, The time integration of the first signal strength when the absolute value of the first coil current is the first coil current value is larger than the time integration of the third signal strength when the absolute value of the first coil current is the first coil current value.

8. The magnetic recording device according to claim 1, The first magnetic layer contains a first element, the first element including at least one of Fe, Co and Ni, The second magnetic layer contains the first element and a second element, the second element including at least one selected from 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.

9. The magnetic recording device according to claim 1, At least any one of the first non-magnetic layer, the second non-magnetic layer and the third non-magnetic layer contains a third element, the third element including at least one selected from Cu, Au, Cr, V, Al and Ag.

10. The magnetic recording device according to claim 1, In the first operation, an alternating magnetic field is generated from the magnetic element.

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