Magnetic recording device

Abstract

To provide a magnetic recording device that enables improved recording density. [Solution] According to the embodiment, the magnetic recording device includes a magnetic head and a control unit. The magnetic head includes first and second magnetic poles, 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 is configured to supply a recording element current to the magnetic element and a recording coil current to the coil. The absolute value of the recording coil current is less than or equal to the first coil current value corresponding to the first peak.

Description

Technical Field

[0001] Embodiments of the present invention relate to a magnetic recording device.

Background Art

[0002] Information is recorded on a magnetic recording medium such as an HDD (Hard Disk Drive) using a magnetic head. In a magnetic recording device, an improvement in recording density is desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

Means for Solving the Problems

[0005] According to embodiments of the present invention, a magnetic recording device includes a magnetic head and a control unit. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element provided between the first magnetic pole and the second magnetic pole, a coil, a first terminal, and a second terminal. The first terminal is electrically connected to a part of the magnetic element, and the second terminal is electrically connected to another part of the magnetic element. The magnetic element 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. 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 intensity 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 intensity 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 to the second magnetic layer. The second current has a second direction from the second magnetic layer to the first magnetic layer. The second absolute value of the second current is the same as the first absolute value of the first current. When the absolute value of the first coil current is changed, the change in the absolute value of the difference between the time integration of the first signal intensity and the time integration of the second signal intensity includes a first peak and a second peak. The first coil current value of the absolute value of the first coil current corresponds to the first peak. The second coil current value of the absolute value of the first coil current corresponds to the second peak. The first coil current value is greater than the second coil current value. The control unit is configured to perform the first operation. In the first operation, the control unit is configured to supply a recording element current to the magnetic element while simultaneously supplying a recording coil current to the coil. The absolute value of the recording coil current is less than or equal to the first coil current value. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a schematic cross-sectional view illustrating a magnetic recording device according to the first embodiment. [Figure 2] Figures 2(a) and 2(b) are schematic diagrams illustrating a part of the magnetic recording device according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram illustrating the operation of a magnetic recording device according to the first embodiment. [Figure 4] Figures 4(a) to 4(c) are graphs illustrating the characteristics of the magnetic recording device according to the first embodiment. [Figure 5] Figures 5(a) to 5(c) are graphs illustrating the characteristics of the magnetic recording device according to the first embodiment. [Figure 6] Figures 6(a) and 6(b) are schematic plan views illustrating a magnetic head according to the first embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view illustrating a magnetic head according to an embodiment. [Figure 8] Figure 8 is a schematic perspective view illustrating a magnetic recording device according to an embodiment. [Figure 9] Figure 9 is a schematic perspective view illustrating a part of a magnetic recording apparatus according to an embodiment. [Figure 10] Figure 10 is a schematic perspective view illustrating a magnetic recording device according to an embodiment. [Figure 11] Figures 11(a) and 11(b) are schematic perspective views illustrating a part of a magnetic recording apparatus according to an embodiment. [Modes for carrying out the invention]

[0007] The embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may be depicted differently in different drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.

[0008] (First Embodiment) Figure 1 is a schematic cross-sectional view illustrating a magnetic recording device according to the first embodiment. Figures 2(a) and 2(b) are schematic diagrams illustrating a part of the magnetic recording device according to the first embodiment. Figure 2(a) is a cross-sectional view. Figure 2(b) is a plan view along arrow AR1 in Figure 2(a). Figure 3 is a schematic diagram illustrating the operation of a magnetic recording device according to the first embodiment. Figures 4(a) to 4(c) are graphs illustrating the characteristics of the magnetic recording device according to the first embodiment. Figures 5(a) to 5(c) are graphs illustrating the characteristics of the magnetic recording device according to the first embodiment.

[0009] As shown in Figure 1, the magnetic recording device 210 according to this embodiment includes a magnetic head 110 and a control unit 10D. 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.

[0010] The magnetic head 110 includes a recording unit 60. As will be described later, the magnetic head 110 may also include a playback unit. The recording unit 60 includes a first magnetic pole 31, a second magnetic pole 32, and a magnetic element 20. The magnetic element 20 is provided between the first magnetic pole 31 and the second magnetic pole 32.

[0011] 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 principal magnetic pole. The second magnetic pole 32 is, for example, a trailing shield. Alternatively, the first magnetic pole 31 may be a trailing shield and the second magnetic pole 32 may be a principal magnetic pole.

[0012] 设定从磁记录介质80到磁头110的方向为Z轴方向。还同时,将与Z轴方向的垂直的一个方向设定为X轴方向。并且,将针对Z轴方向和X轴方向垂直的方向设定为Y轴方向。Z轴方向例如对应层高方向。类似地,X轴方向例如对应沿下轨道方向。Y轴方向例如对应跨轨道方向。沿着下轨道方向,磁记录介质80和磁头110相对移动。在磁记录介质80的目标位置,施加从磁头110产生的磁场(记录磁场)。磁记录介质80的目标位置的磁化被控制为与记录磁场相应的方向。由此,信息被记录在磁记录介质80上。

[0013] Set the direction from the first pole 31 to the second pole 32 as the first direction D1. The first direction D1 substantially follows the X-axis direction, and in the embodiment, the first direction D1 may be inclined at a small angle with respect to the X-axis direction.

[0014] As shown in FIG. 1, the first pole 31 includes a medium-facing surface 30F. The medium-facing surface 30F is, for example, an ABS (Air Bearing Surface), faces the magnetic recording medium 80, and is along the X-Y plane.

[0015] As shown in FIG. 1, the magnetic head 110 further includes a coil 30c. In this example, a part of the coil 30c is between the first pole 31 and the second pole 32. A shield 33 is provided, and the first pole 31 is between the shield 33 and the second pole 32 in the X-axis direction. Another part of the coil 30c is between the shield 33 and the first pole 31, and an insulating portion 30i is provided between these elements. The shield 33 is, for example, a leading shield, and the magnetic head 110 may include a side shield (not shown).

[0016] As shown in Figure 1, the control unit 10D may include a recording circuit 30D and an element electrical circuit 20D. A recording current (recording coil current Icw) is supplied from the recording circuit 30D to the coil 30c. A recording magnetic field is applied to the magnetic recording medium 80 from at least one of the first magnetic pole 31 and the second magnetic pole 32, corresponding to the recording coil current Icw.

[0017] As shown in Figure 1, the element electrical circuit 20D is electrically connected to the magnetic element 20. In this example, the magnetic element 20 is electrically connected to a first magnetic pole 31 and a 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 element 20. The second terminal T2 is electrically connected to another portion of the magnetic element 20. For example, the first terminal T1 is electrically connected to the magnetic element 20 via a first wiring W1 and the first magnetic pole 31. For example, the second terminal T2 is electrically connected to the magnetic element 20 via a second wiring W2 and the second magnetic pole 32. From the element electrical circuit 20D, for example, a recording element current Idw is supplied to the magnetic element 20. The recording element current Idw is, for example, a DC current.

[0018] As shown in Figures 2(a) and 2(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. In Figures 2(a) and 2(b), the insulating portion 30i is omitted.

[0019] 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.

[0020] 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.

[0021] As shown in Figure 2(b), a recording element current Idw is supplied to such a magnetic element 20. The recording element current Idw is supplied, for example, from the element electrical circuit 20D described above. As shown in Figure 2(b), the recording element current Idw has a direction from the first magnetic layer 21 to the second magnetic layer 22. As shown in Figure 2(b), the electron flow je associated with 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.

[0022] For example, when an external magnetic field is applied to the magnetic element 20, a recording element current Idw exceeding a threshold flows through 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 by 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. The generation of an alternating magnetic field when a recording element current Idw exceeding a threshold flows through the magnetic element 20 while a magnetic field is applied to the magnetic element 20 is thought to be due to, for example, the oscillation of the magnetization 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 above-mentioned recording coil current Icw may function as the magnetic field applied to the magnetic element 20.

[0023] The following describes examples of the characteristics of such magnetic element 20. Figure 3 illustrates a test first coil current Ic1 supplied to coil 30c. The horizontal axis in Figure 3 represents time tm, and 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. In Figure 3, 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 a square wave.

[0024] It was found that when a current (for example, a first current Id1 or a second current Id2) is supplied to the magnetic element 20 while a first coil current Ic1 for testing is supplied, a specific change occurs in the current passing through the magnetic element 20.

[0025] 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 are greater than 0 and less than the element current value Idth. The element current value Idth is, for example, the threshold current and 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 greater than or equal to the element current value Idth.

[0026] Figures 4(a) to 4(c) illustrate the first signal strength SS1 of the first signal Sg1 generated in the first current Id1 when the first current Id1 is supplied to the magnetic element 20. Figures 4(a) to 4(c) illustrate the second signal strength SS2 of the second signal Sg2 generated in the second current Id2 when the second current Id2 is supplied to the magnetic element 20. The first current Id1 has a first direction from the first magnetic layer 21 to the second magnetic layer 22 (see Figure 2(b)). The second current Id2 has a second direction from the second magnetic layer 22 to the first magnetic layer 21 (see Figure 2(b)).

[0027] 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., to the magnetic element 20), a first signal Sg1 having a first signal intensity SS1 of the first component of the first frequency f1 is generated between the first terminal T1 and the second terminal T2. The first signal Sg1 may be, for example, a voltage signal or a power signal.

[0028] 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., to the magnetic element 20), a second signal Sg2 having a second signal strength SS2 of the second component of 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 a power signal.

[0029] Figures 4(a) to 4(c) illustrate 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, using solid lines. Figures 4(a) to 4(c) illustrate the change in the second signal strength SS2 of the second signal Sg2 when the absolute value of the first coil current Ic1 is changed, using dashed lines. In Figures 4(a) and 4(b), the dashed line (second signal Sg2) substantially overlaps with the solid line (first signal Sg1). In Figure 4(c), the dashed line (second signal Sg2) does not overlap with the solid line (first signal Sg1) in most parts.

[0030] As shown in Figure 4(a), when the first absolute value of the first current Id1 is 0, the first signal intensity SS1 of the first signal Sg1 increases gradually with increasing absolute value of the first coil current Ic1. When the second absolute value of the second current Id2 is 0, the second signal intensity SS2 of the second signal Sg2 increases gradually with increasing absolute value of the first coil current Ic1. The second signal intensity SS2 is substantially the same as the first signal intensity SS1.

[0031] As shown in Figure 4(b), when the first absolute value of the first current Id1 is greater than 0 and less than the element current value Idth (threshold), the first signal intensity SS1 of the first signal Sg1 increases gradually with increasing absolute value of the first coil current Ic1. When the second absolute value of the second current Id2 is greater than 0 and less than the element current value Idth (threshold), the second signal intensity SS2 of the second signal Sg2 increases gradually with increasing absolute value of the first coil current Ic1. The first signal intensity SS1 is substantially the same as the second signal intensity SS2.

[0032] For example, the magnetic element 20, the first wiring W1, the first magnetic pole 31, the second wiring W2, and the second magnetic pole 32 are thought to be affected by electromagnetic induction from the first coil current Ic1. As illustrated in Figures 4(a) and 4(b), the first signal strength SS1 and the second signal strength SS2 increase with increasing absolute value of the first coil current Ic1. This phenomenon is thought to be due to the fact that the influence of electromagnetic induction from the first coil current Ic1 becomes greater as the absolute value of the first coil current Ic1 increases.

[0033] Figure 4(b) illustrates the characteristics of a third signal Sg3 with a second frequency, not the first frequency f1. In this example, the third signal Sg3 is a component of the second frequency, which is 1.1 times the first frequency f1. As shown in Figure 4(b), the intensity of the first signal Sg1, which is the first component of the first current Id1 at 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 at the first frequency f1, is higher than the intensity of the third signal Sg3.

[0034] The characteristics in Figure 4(b) show that the first current Id1 and the second current Id2 supplied to the element are affected by the first coil current Ic1. In Figure 4(b), the effect of the first coil current Ic1 is considered to be an electromagnetic effect caused by the first coil current Ic1 which changes at the first frequency f1.

[0035] As shown in Figure 4(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 intensity SS1 of the first signal Sg1 is different from the second signal intensity SS2 of the second signal Sg2. This phenomenon is thought to be caused by a 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 through the magnetic element 20 that is greater than the threshold.

[0036] As shown in Figure 4(c), when the absolute value of the first coil current Ic1 is small, the first signal intensity SS1 of the first signal Sg1 substantially coincides with the second signal intensity SS2 of the second signal Sg2.

[0037] When the absolute value of the first coil current Ic1 is greater than or equal to the second coil current value Icv2, the first signal intensity SS1 of the first signal Sg1 is different from the second signal intensity SS2 of the second signal Sg2.

[0038] The following explains the difference ΔS1 between the time integration of the first signal intensity SS1 of the first component of the first signal Sg1 at the first frequency f1, and the time integration of the second signal intensity SS2 of the second component of the second signal Sg2 at the first frequency f1.

[0039] Figures 5(a) to 5(c) illustrate the difference ΔS1 when the absolute value of the first coil current Ic1 is changed. The difference ΔS1 is the difference between the time integration of the first signal intensity SS1 of the first component of the first signal Sg1 at the first frequency f1 and the time integration of the second signal intensity SS2 of the second component of the second signal Sg2 at the first frequency f1.

[0040] As shown in Figure 5(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 effectively 0.

[0041] As shown in Figure 5(b), even when the first absolute value of the first current Id1 and the second absolute value of the second current Id2 are greater than 0 and less than the element current value Idth (threshold), the difference ΔS1 is effectively 0.

[0042] Figure 5(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 greater than or equal to the element current value Idth (threshold). When the absolute value of the first coil current Ic1 changes, the change in the difference ΔS1 includes peaks (e.g., the first peak pk1 and the second peak pk2).

[0043] Thus, when the absolute value of the first coil current Ic1 is changed, the change in the absolute value of the difference ΔS1 between the time integration of the first signal intensity SS1 and the time integration of the second signal intensity SS2 includes the first peak pk1 and the second peak pk2. The absolute value of the first coil current Ic1, the first coil current value Icv1, corresponds to the first peak pk1. When the absolute value of the first coil current Ic1 is the first coil current value Icv1, the difference ΔS1 becomes the first peak pk1. The absolute value of the first coil current Ic1, the second coil current value Icv2, corresponds to the second peak pk2. When the absolute value of the first coil current Ic1 is 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.

[0044] 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 affected by the first coil current Ic1 and the first current Id1. For example, the magnetic field based on the first coil current Ic1 and 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, magnetization oscillation can be efficiently obtained.

[0045] If 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 exceeds the first coil current value Icv1, then the magnetic element 20 is considered to be excessively affected by the first coil current Ic1. For example, the efficiency of generating an alternating magnetic field from the magnetic element 20 decreases.

[0046] The recording coil current Icw during the recording operation may be set based on the characteristics illustrated in Figure 4(c) or Figure 5(c).

[0047] 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 while simultaneously supplying a recording coil current Icw to the coil 30c. The absolute value of the recording coil current Icw is less than or equal to the first coil current value Icv1. This suppresses, for example, a decrease in the efficiency of generating an AC magnetic field from the magnetic element 20. This enables efficient recording. As a result, a magnetic recording device capable of improving recording density can be provided.

[0048] The element current Idw during recording has the first orientation described above. The absolute value of the element current Idw during recording is greater than or equal to the element current value Idth (threshold). The first absolute value of the first current Id1 and the second absolute value of the second current Id2, which are referenced in the first operation, are greater than or equal to the element current value Idth (threshold).

[0049] In this embodiment, the absolute value of the recording coil current Icw may be greater than or equal to the second coil current value Icv2. The magnetic field based on the first coil current Ic1 and 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 more effectively generated from the magnetic element 20.

[0050] As shown in Figure 5(c), the first coil current value Icv1 is substantially three times the second coil current value Icv2. In this embodiment, the first coil current value Icv1 may be between 2.5 and 3.5 times the second coil current value Icv2.

[0051] The first height of the first peak pk1 may be higher than the second height of the second peak pk2. The first peak pk1 may be more distinct than the second peak pk2.

[0052] The changes in the first peak pk1 and the second peak pk2 with respect to the increase or decrease in the absolute value of the first coil current Ic1 may 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 the range less than the first coil current value Icv1 is greater than the steepness of the change in the first peak pk1 when the absolute value of the first coil current Ic1 changes within the range greater than the first coil current value Icv1. The steepness of the change in the second peak pk2 when the absolute value of the first coil current Ic1 changes within the range less than the second coil current value Icv2 is greater than the steepness of the change in the second peak pk2 when the absolute value of the first coil current Ic1 changes within the range greater than the second coil current value Icv2.

[0053] As already explained, if 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), then the change in the absolute value of the difference ΔS1 between the time integration of the first signal strength SS1 and the time integration of the second signal strength SS2 when the absolute value of the first coil current Ic1 is changed does not need to substantially include the first peak pk1 and the second peak pk2.

[0054] For example, as explained with respect to Figure 4(b), when a first coil current Ic1 with a first frequency f1 is supplied to the coil 30c and a first current Id1 is supplied between the first terminal T1 and the second terminal T2 (i.e., to the magnetic element 20), a third signal Sg3 having a third component of a second frequency and a third signal strength SS3 may be generated between the first terminal T1 and the second terminal T2. The time integration of the first signal strength SS1 when the absolute value of the first coil current Ic1 is the second coil current value Icv2 may be greater than the time integration 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 may 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 may be, for example, a voltage signal or a power signal.

[0055] For example, when the absolute value of the first coil current Ic1 is equal to the first coil current value Icv1, the time integration of the first signal intensity SS1 is greater than the time integration of the third signal intensity SS3 when the absolute value of the first coil current Ic1 is equal to the first coil current value Icv1.

[0056] For example, when the absolute value of the first coil current Ic1 changes, the change in the difference between the time integration of the first signal intensity SS1 and the time integration of the third signal intensity SS3 may include a peak. For example, when the absolute value of the first coil current Ic1 changes, the absolute value of the first coil current Ic1 at which the change in the difference between the time integration of the first signal intensity SS1 and the time integration of the third signal intensity SS3 shows a peak may be substantially the same as the absolute value of the first coil current Ic1 at which the change in the difference ΔS1 shows a peak.

[0057] In this embodiment, the first frequency f1 of the first coil current Ic1 may be, for example, 1 MHz or more and 4 GHz or less. The frequency of the alternating magnetic field based on the oscillation of the magnetic element 20 may be, for example, 5 GHz or more and 50 GHz or less. For example, the first frequency f1 may be lower than the frequency of the alternating magnetic field based on the oscillation.

[0058] In the embodiment, at least one of the first non-magnetic layer 41, the second non-magnetic layer 42, and the third non-magnetic layer 43 contains 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 containing such a material, for example, high spin transmittance can be obtained. For example, high oscillation intensity can be obtained.

[0059] At least one of the second non-magnetic layer 42 and the third non-magnetic 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 non-magnetic layer containing such a material, for example, a low spin transmittance can be obtained. For example, stable oscillation can be easily obtained. At least one of the second non-magnetic layer 42 and the third non-magnetic layer 43 may contain the above-mentioned third and fourth elements.

[0060] In this embodiment, the first magnetic layer 21 contains a first element. The first element contains at least one of Fe, Co, and Ni.

[0061] The second magnetic layer 22 contains the first element and the 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 contain the second element, or 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.

[0062] For example, the concentration of the above-mentioned second element in the second magnetic layer 22 is between 10 atomic percent and 80 atomic percent. The second magnetic layer 22 containing such a material has, for example, negative spin polarization. On the other hand, for example, the first magnetic layer 21 has positive spin polarization.

[0063] With the first magnetic layer 21 and the second magnetic layer 22, a stable alternating magnetic field of high intensity can be obtained.

[0064] In the magnetic head 110, the first magnetic layer 21 and the second magnetic layer 22 function as, for example, oscillation layers. 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.

[0065] As shown in Figure 2(b), the thickness of the first magnetic layer 21 along the first direction D1 (the direction 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 this embodiment, for example, the first thickness t1 may be the same as the second thickness t2. This makes it easier to obtain oscillation, as will be described later.

[0066] The thickness of the first non-magnetic layer 41 along the first direction D1 is set to thickness t41. The thickness of the second non-magnetic layer 42 along the first direction D1 is set to thickness t42. The thickness of the third non-magnetic layer 43 along the first direction D1 is set to thickness t43. These thicknesses are, for example, between 0.5 nm and 6 nm. When these thicknesses are 0.5 nm or more, stable oscillation becomes easier. When these thicknesses are 6 nm or less, for example, the spin transmittance tends to be higher. For example, high oscillation intensity is easier to obtain.

[0067] Let the thickness ratio R1 be the ratio of the first thickness t1 to the second thickness t2 (i.e., t1 / t2). When the thickness ratio R1 is close to 1, a high oscillation intensity can be obtained. For example, stable oscillation can be obtained when the thickness ratio R1 is between 0.25 and 4. The thickness ratio R1 can also be 0.33 or higher, and an even higher oscillation intensity can be obtained. The thickness ratio R1 can also be 3 or lower, and an even higher oscillation intensity can be obtained.

[0068] In the embodiment, the first thickness t1 is preferably 0.25 to 4 times the second thickness t2. This allows for high oscillation intensity and stable oscillation. The first thickness t1 may also be 0.33 to 3 times the second thickness t2. This allows for even higher oscillation intensity and more stable oscillation. According to the embodiment, stable MAMR can be implemented, and a magnetic head capable of improving recording density can be provided.

[0069] The first thickness t1 is preferably 5 nm or more. The first thickness t1 may be, for example, 20 nm or less. For example, the distance between the first magnetic pole 31 and the second magnetic pole 32 (e.g., the recording gap) can be shortened. For example, a high recording density can be easily obtained. The second thickness t2 is preferably 5 nm or more. 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. The sum ts of the first thickness t1 and the second thickness t2 is preferably 15 nm or more. This allows for high oscillation intensity. 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.

[0070] Figures 6(a) and 6(b) are schematic plan views illustrating a magnetic head according to the first embodiment. As shown in Figure 6(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 one of the first magnetic layer 21 and the second magnetic layer 22 includes multiple regions. Other configurations in the magnetic head 111 may be the same as those in the magnetic head 110.

[0071] 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. This makes it easier to obtain stable oscillation, for example.

[0072] For example, the saturation magnetization of the first magnetic region 21a is 1.2 times or more the saturation magnetization 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 the saturation magnetization of the second magnetic region 21b. This also makes it easier to obtain stable oscillation.

[0073] 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 tends to be greater than the saturation magnetization of the second magnetic region 21b. For example, the Ni concentration in the first magnetic region 21a is lower than the Ni concentration in the second magnetic region 21b. As a result, for example, the saturation magnetization of the first magnetic region 21a tends 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.

[0074] 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. This makes it easier to obtain stable oscillation, for example.

[0075] For example, the saturation magnetization of the third magnetic region 22c is 1.2 times or more the saturation magnetization 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 the saturation magnetization of the fourth magnetic region 22d. This also makes it easier to obtain stable oscillation.

[0076] 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 tends to be higher than the saturation magnetization of the fourth magnetic region 22d. For example, the concentration of the second element in the third magnetic region 22c is lower than the concentration of the second element in the fourth magnetic region 22d. As a result, for example, the saturation magnetization of the third magnetic region 22c tends to be higher than the saturation magnetization 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.

[0077] As shown in Figure 6(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 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 addition to a third magnetic layer 23. Other configurations in the magnetic head 112 may be the same as those in the magnetic head 110 or magnetic head 111.

[0078] 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 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, or 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.

[0079] 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.

[0080] 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, which are aligned in the first direction D1 (direction from the first magnetic pole 31 to the second magnetic pole 32). For example, high oscillation intensity can be obtained. Stable oscillation can be obtained.

[0081] The following describes examples of magnetic heads and magnetic recording media 80 included in the magnetic recording device 210 according to the embodiment. Figure 7 is a schematic cross-sectional view illustrating a magnetic head according to an embodiment. As shown in Figure 7, in the magnetic head according to the embodiment (for example, magnetic head 110), the 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 magnetic element 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 denoted as angle θ1. Angle θ1 is, for example, 15 degrees or more and 30 degrees or less. Angle θ1 may also be 0 degrees.

[0082] 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 magnetic element 20, and the interface between the magnetic element 20 and the second magnetic pole 32 may be inclined with respect to the X-axis direction.

[0083] The following describes examples of magnetic heads and magnetic recording media 80 included in the magnetic recording device 210 according to the embodiment.

[0084] Figure 8 is a schematic perspective view illustrating a magnetic recording device according to an embodiment. As shown in Figure 8, the magnetic head according to the embodiment (for example, 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 playback unit 70. The recording unit 60 of the magnetic head 110 records information on the magnetic recording medium 80. The playback unit 70 reproduces the information recorded on the magnetic recording medium 80.

[0085] The magnetic recording medium 80 includes, for example, a media substrate 82 and a magnetic recording layer 81 provided on the media substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording unit 60.

[0086] The regeneration unit 70 includes, for example, a first regeneration magnetic shield 72a, a second regeneration magnetic shield 72b, and a magnetic regeneration element 71. The magnetic regeneration element 71 is provided between the first regeneration magnetic shield 72a and the second regeneration magnetic shield 72b. The magnetic regeneration element 71 is capable of outputting a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0087] As shown in Figure 8, the magnetic recording medium 80 moves relative to the magnetic head 110 in the direction of 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.

[0088] Figure 9 is a schematic perspective view illustrating a part of a magnetic recording apparatus according to an embodiment. Figure 9 illustrates a head slider. The magnetic head 110 is mounted on a head slider 159. The head slider 159 includes, for example, Al2O3 / TiC. The head slider 159 moves relative to the magnetic recording medium, either floating above or in contact with it.

[0089] The head slider 159 has, for example, an air inlet side 159A and an air outlet side 159B. The magnetic head 110 is positioned on the side of the air outlet side 159B of the head slider 159. As a result, the magnetic head 110 moves relative to the magnetic recording medium while floating above or in contact with it.

[0090] Figure 10 is a schematic perspective view illustrating a magnetic recording device according to an embodiment. As shown in Figure 10, a rotary actuator is used in the magnetic recording device 150 according to this embodiment. The recording medium disk 180 is mounted on a spindle motor 180M. The recording medium disk 180 rotates in the direction of arrow AR by the spindle motor 180M. The spindle motor 180M responds to a control signal from the drive unit control. The magnetic recording device 150 according to this embodiment may include a plurality of recording medium disks 180. The magnetic recording device 150 may also include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). For example, a non-volatile memory such as flash memory is used for the recording medium 181. For example, the magnetic recording device 150 may also be a hybrid HDD (Hard Disk Drive).

[0091] The head slider 159 records and plays back information to be recorded on the recording medium disk 180. The head slider 159 is located at the tip of a thin-film suspension 154. A magnetic head according to this embodiment is located near the tip of the head slider 159.

[0092] As the recording medium disk 180 rotates, the pressing pressure from the suspension 154 and the pressure generated on the media-facing surface (ABS) of the head slider 159 are balanced. The distance between the media-facing surface of the head slider 159 and the surface of the recording medium disk 180 becomes a predetermined amount of levitation. In this embodiment, the head slider 159 may be in contact with the recording medium disk 180. For example, a contact-running type may be applied.

[0093] The suspension 154 is connected to one end of an arm 155 (for example, an actuator arm). The arm 155 has, for example, a bobbin section. The bobbin section 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 section 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. A magnetic head is provided at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0094] The arm 155 is held by ball bearings. Ball bearings are provided at two locations, above and below the bearing portion 157. The arm 155 can rotate and slide by a voice coil motor 156. The magnetic head can move to any position on the recording medium disk 180.

[0095] Figures 11(a) and 11(b) are schematic perspective views illustrating a part of a magnetic recording apparatus according to an embodiment. Figure 11(a) illustrates a part of the configuration of a magnetic recording device and is an enlarged perspective view of the head stack assembly 160. Figure 11(b) is a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA) 158, which is part of the head stack assembly 160.

[0096] As shown in Figure 11(a), the head stack assembly 160 includes a bearing section 157, a head gimbal assembly 158, and a support frame 161. The head gimbal assembly 158 extends from the bearing section 157. The support frame 161 extends from the bearing section 157. The direction in which the support frame 161 extends is opposite to the direction in which the head gimbal assembly 158 extends. The support frame 161 supports the coil 162 of the voice coil motor 156.

[0097] As shown in Figure 11(b), the head gimbal assembly 158 includes an arm 155 extending from a bearing portion 157 and a suspension 154 extending from the arm 155.

[0098] A head slider 159 is provided at the tip of the suspension 154. A magnetic head according to the embodiment is provided on the head slider 159.

[0099] The magnetic head assembly (head gimbal assembly) 158 according to the embodiment includes a magnetic head according to the embodiment, a head slider 159 on which the magnetic head is provided, 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.

[0100] The suspension 154 may have, for example, lead wires (not shown) for recording and reproducing signals. The suspension 154 may also have, for example, lead wires (not shown) for heaters for adjusting the amount of levitation. The suspension 154 may also have, for example, lead wires (not shown) for a spin transfer torque oscillator. These lead wires are electrically connected to a plurality of electrodes provided on the magnetic head.

[0101] A signal processing unit 190 is provided in the magnetic recording device 150. The signal processing unit 190 records and reproduces signals on a magnetic recording medium using a magnetic head. The input and output lines of the signal processing unit 190 are connected, for example, to the electrode pads of the head gimbal assembly 158 and are electrically connected to the magnetic head.

[0102] 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 allows the magnetic recording medium and the magnetic head to move relative to each other while separated or in contact. The position control unit aligns the magnetic head to 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.

[0103] For example, a recording medium disk 180 is used as the magnetic recording medium. The movable part includes, for example, a head slider 159. The position control unit includes, for example, a head gimbal assembly 158.

[0104] The embodiments may include the following technical proposals. (Technical proposal 1) Magnetic head and Control unit and Equipped with, The aforementioned magnetic head is The first magnetic pole and, The second magnetic pole and, A magnetic element provided between the first magnetic pole and the second magnetic pole, First terminal and, The second terminal and Coil and, Includes, The first terminal is electrically connected to a part of the magnetic element, The second terminal is electrically connected to another part of the magnetic element, The aforementioned magnetic circuit is The first magnetic layer and A second magnetic layer is provided between the first magnetic layer and the second magnetic pole, A first non-magnetic layer is provided between the first magnetic layer and the second magnetic layer, A second non-magnetic layer is provided between the second magnetic layer and the second magnetic pole, A third non-magnetic layer is provided between the first magnetic pole and the first magnetic layer, Includes, 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 intensity 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 the 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 to the second magnetic layer, The second current has a second direction from the second magnetic layer to the first magnetic layer, The second absolute value of the second current is the same as the first absolute value of the first current. When the absolute value of the first coil current is changed, the change in the absolute value of the difference between the time integration of the first signal intensity and the time integration of the second signal intensity includes the first peak and the second peak. The absolute value of the first coil current corresponds to the first peak. The second coil current value, which is the absolute value of the first coil current, corresponds to the second peak. The current value of the first coil is greater than the current value of the second coil. The control unit is configured to perform the first operation, In the first operation, the control unit is configured to supply a recording element current to the magnetic element while simultaneously supplying a recording coil current to the coil. A magnetic recording device in which the absolute value of the recording coil current is less than or equal to the first coil current value.

[0105] (Technical proposal 2) The magnetic recording apparatus according to Technical Proposal 1, wherein the absolute value of the recording coil current is greater than or equal to the second coil current value.

[0106] (Technical proposal 3) The magnetic recording apparatus according to Technical Proposal 1 or 2, wherein the current value of the first coil is 2.5 times or more and 3.5 times or less the current value of the second coil.

[0107] (Technical proposal 4) The first absolute value and the second absolute value are greater than or equal to the element current value. The absolute value of the element current during recording is greater than or equal to the element current value. The recording element current has the first orientation, as described in any one of the technical proposals 1 to 3.

[0108] (Technical proposal 5) If the first absolute value and the second absolute value are less than the element current value, The magnetic recording apparatus according to Technical Proposal 4, wherein when the absolute value of the first coil current is changed, the change in the absolute value of the difference between the time integration of the first signal intensity and the time integration of the second signal intensity substantially does not include the first peak and the second peak.

[0109] (Technical proposal 6) 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 of a second frequency is generated between the first terminal and the second terminal. A magnetic recording apparatus according to any one of Technical Proposals 1 to 5, wherein the time integration of the first signal intensity when the absolute value of the first coil current is the second coil current value is greater than the time integration of the third signal intensity when the absolute value of the first coil current is the second coil current value.

[0110] (Technical proposal 7) The magnetic recording apparatus according to Technical Proposal 6, wherein the time integration of the first signal intensity when the absolute value of the first coil current is the first coil current value is greater than the time integration of the third signal intensity when the absolute value of the first coil current is the first coil current value.

[0111] (Technical proposal 8) The first magnetic layer comprises a first element including at least one of Fe, Co, and Ni. The second magnetic layer comprises the first element and a second element which includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. A magnetic recording apparatus according to any one of Technical Proposals 1 to 7, wherein 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.

[0112] (Technical proposal 9) The magnetic element further includes a third magnetic layer, The third magnetic layer is provided between the second magnetic layer and the second non-magnetic layer. The third magnetic layer comprises at least one of Fe, Co, and Ni. The magnetic recording apparatus according to Technical Proposal 8, 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.

[0113] (Technical proposal 10) The magnetic recording apparatus according to Technical Proposal 8 or 9, wherein the concentration of the second element in the second magnetic layer is 10 atomic% or more and 80 atomic% or less.

[0114] (Technical proposal 11) A magnetic recording apparatus according to any one of Technical Proposals 1 to 10, wherein the first thickness of the first magnetic layer along the first direction from the first magnetic pole to the second magnetic pole is 0.25 times or more and 4 times or less the second thickness of the second magnetic layer along the first direction.

[0115] (Technical proposal 12) The first magnetic layer includes a first magnetic region and a second magnetic region. The second magnetic region is located between the first magnetic region and the first non-magnetic layer. A magnetic recording apparatus according to any one of Technical Proposals 1 to 11, wherein the saturation magnetization of the first magnetic region is greater than the saturation magnetization of the second magnetic region.

[0116] (Technical proposal 13) The second magnetic layer includes a third magnetic region and a fourth magnetic region. The fourth magnetic region is located between the third magnetic region and the first non-magnetic layer. A magnetic recording apparatus according to any one of Technical Proposals 1 to 12, wherein the saturation magnetization of the third magnetic region is greater than the saturation magnetization of the fourth magnetic region.

[0117] (Technical proposal 14) The magnetic recording apparatus according to any one of the technical proposals 1 to 13, wherein the third non-magnetic layer is in contact with the first magnetic pole and the first magnetic layer.

[0118] (Technical proposal 15) The magnetic recording apparatus according to any one of Technical Proposals 1 to 14, wherein the first non-magnetic layer is in contact with the first magnetic layer and the second magnetic layer.

[0119] (Technical proposal 16) The second non-magnetic layer is in contact with the second magnetic layer and the second magnetic pole, as described in any one of Technical Proposals 1 to 8, in the magnetic recording apparatus.

[0120] (Technical proposal 17) A magnetic recording apparatus according to any one of the Technical Proposals 1 to 16, wherein at least one of the first non-magnetic layer, the second non-magnetic layer, and the third non-magnetic layer contains a third element, which includes at least one selected from the group consisting of Cu, Au, Cu, V, Al, and Ag.

[0121] (Technical proposal 18) The first magnetic layer includes a first magnetic region and a second magnetic region. The second magnetic region is located between the first magnetic region and the first non-magnetic layer. A magnetic recording apparatus according to any one of Technical Proposals 1 to 11, wherein the concentration of Fe in the first magnetic region is higher than the concentration of Fe in the second magnetic region.

[0122] (Technical proposal 19) The second magnetic layer includes a third magnetic region and a fourth magnetic region. The fourth magnetic region is located between the third magnetic region and the first non-magnetic layer. A magnetic recording apparatus according to any one of Technical Proposals 1 to 12, wherein the concentration of Fe in the third magnetic region is higher than the concentration of Fe in the fourth magnetic region.

[0123] (Technical proposal 20) A magnetic recording apparatus according to any one of Technical Proposals 1 to 19, wherein an alternating magnetic field is generated from the magnetic element in the first operation.

[0124] According to this embodiment, a magnetic recording device capable of improving recording density can be provided.

[0125] In this specification, "perpendicular" and "parallel" do not mean strictly perpendicular and strictly parallel, but also include variations in the manufacturing process, for example, and it is sufficient if they are substantially perpendicular and substantially parallel.

[0126] 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, the specific configuration of each element included in a magnetic recording device, such as a magnetic head, magnetic poles, magnetic elements, magnetic layers, non-magnetic layers, wiring, magnetic recording media, 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 range to implement the present invention and obtain similar effects.

[0127] Combinations of two or more elements from any of the specific examples, to the extent technically feasible, are also included within the scope of the present invention, insofar as they encompass the gist of the invention.

[0128] Furthermore, all magnetic recording devices that can be implemented by those skilled in the art by appropriately modifying the design based on the magnetic recording device described above as an embodiment of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention.

[0129] Furthermore, within the scope of the concept of the present invention, a person skilled in the art could conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention.

[0130] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0131] 10D: Control unit, 20: Magnetic element, 20D: Element electrical circuit, 21~23: First to third magnetic layers, 21a, 21b: First and second magnetic regions, 22c, 22d: Third and fourth magnetic regions, 30D: Recording circuit, 30F: Media-facing surface, 30c: Coil, 30i: Insulation part, 31, 32: First and second magnetic poles, 33: Shield, 41~43: First to third non-magnetic layers, 60: Recording unit, 70: Reproduction unit, 71: Magnetic reproduction element, 72a, 72b: First and second reproduction magnetic shields, 80: Magnetic recording medium, 81: Magnetic recording layer, 82: Media substrate, 83: Magnetization, 85: Media movement direction, 110~112: Magnetic head, 150: Magnetic recording device, 154: Suspension, 155: Arm, 156: Voice coil motor, 157: Bearing section, 158: Head gimbal assembly, 159: Head slider, 159A: Air inlet side, 159B: Air outlet side, 160: Head stack assembly, 161: Support frame, 162: Coil, 180: Recording medium disk, 180M: Spindle motor, 181: Recording medium, 190: Signal processing unit, 210: Magnetic recording device, AR, AR1: Arrow, D1: First direction, Ic1: First coil current, Icv1, Icv2: First and second coil current values, Icw: Recording coil current, Id1, Id2: First and second currents, Idth: Element current value, Idw: Element current during recording, SS1~SS3: First to third signal intensity, Sg1~Sg3: First to third signals, T1, T2: 1st and 2nd terminals, Tf1: period, W1, W2: 1st and 2nd wiring, f1: 1st frequency, je: electron current, pk1, pk2: 1st and 2nd peaks, t1~t3: 1st to 3rd thickness, tm: time, t41~t43: thickness, θ1: angle

Claims

1. Magnetic head and Control unit and Equipped with, The magnetic head is The first magnetic pole and, The second magnetic pole and, A magnetic element provided between the first magnetic pole and the second magnetic pole, Coil and, First terminal and, The second terminal and, Includes, The first terminal is electrically connected to a part of the magnetic element, The second terminal is electrically connected to another part of the magnetic element. The aforementioned magnetic circuit is The first magnetic layer and A second magnetic layer is provided between the first magnetic layer and the second magnetic pole, A first non-magnetic layer is provided between the first magnetic layer and the second magnetic layer, A second non-magnetic layer is provided between the second magnetic layer and the second magnetic pole, A third non-magnetic layer is provided between the first magnetic pole and the first magnetic layer, Includes, 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 the 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 to the second magnetic layer, The second current has a second direction from the second magnetic layer to the first magnetic layer, The second absolute value of the second current is the same as the first absolute value of the first current. When the absolute value of the first coil current is changed, the change in the absolute value of the difference between the time integration of the first signal intensity and the time integration of the second signal intensity includes the first peak and the second peak. The absolute value of the first coil current corresponds to the first peak. The second coil current value, which is the absolute value of the first coil current, corresponds to the second peak. The current value of the first coil is greater than the current value of the second coil. The control unit is configured to perform the first operation, In the first operation, the control unit is configured to supply a recording element current to the magnetic element while simultaneously supplying a recording coil current to the coil. A magnetic recording device in which the absolute value of the recording coil current is less than or equal to the first coil current value.

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

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

4. The first absolute value and the second absolute value are greater than or equal to the element current value. The absolute value of the element current during recording is greater than or equal to the element current value. The magnetic recording apparatus according to claim 1, wherein the element current during recording has the first orientation.

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

6. 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 of a second frequency is generated between the first terminal and the second terminal. The magnetic recording apparatus according to claim 1, wherein the time integration of the first signal intensity when the absolute value of the first coil current is the second coil current value is greater than the time integration of the third signal intensity when the absolute value of the first coil current is the second coil current value.

7. The magnetic recording apparatus according to claim 6, wherein the time integration of the first signal intensity when the absolute value of the first coil current is the first coil current value is greater than the time integration of the third signal intensity when the absolute value of the first coil current is the first coil current value.

8. The first magnetic layer comprises a first element including at least one of Fe, Co, and Ni. The second magnetic layer comprises the first element and a second element which includes at least one selected from the group consisting of Cr, V, Mn, Ti, and Sc. The magnetic recording apparatus according to any one of claims 1 to 7, wherein 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 apparatus according to claim 1, wherein at least one of the first non-magnetic layer, the second non-magnetic layer, and the third non-magnetic layer contains a third element, which includes at least one selected from the group consisting of Cu, Au, Cu, V, Al, and Ag.

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

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