Magnetic recording device and magnetic recording method

Abstract

The present invention provides a magnetic recording device and a magnetic recording method capable of improving recording capability. According to an embodiment, the magnetic recording device includes a magnetic head, a first circuit, a second circuit, a third circuit and a control unit. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element and a coil. The magnetic element is arranged between the first magnetic pole and the second magnetic pole. The magnetic element includes a first magnetic layer. The first circuit can supply a coil current to the coil. The second circuit can supply an element current to the magnetic element. The third circuit can detect the resistance of the magnetic element. The control unit can control the second circuit based on the resistance detected by the third circuit, thereby controlling the element current.

Description

[0001] This application is based on Japanese Patent Application No. 2020-190702 (filing date November 17, 2020) and claims priority from the Japanese Patent Application No. 2020-190702. The entire contents of the application are incorporated herein by reference. Technical Field

[0002] Embodiments of the present invention relate to a magnetic recording device and a magnetic recording method. Background Art

[0003] A magnetic head is used to record information in a magnetic recording medium such as a HDD (Hard Disk Drive). There is a demand for improving the recording capacity of magnetic recording devices. Summary of the invention

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

[0005] Technical solutions to solve problems

[0006] According to an embodiment of the present invention, a magnetic recording device includes a magnetic head, a first circuit, a second circuit, a third circuit, and a control unit. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, and a coil. The magnetic element is arranged between the first magnetic pole and the second magnetic pole. The magnetic element includes a first magnetic layer. The first circuit can supply a coil current to the coil. The second circuit can supply an element current to the magnetic element. The third circuit can detect the resistance of the magnetic element. The control unit can control the second circuit based on the resistance detected by the third circuit, thereby controlling the element current.

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

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

[0009] Figure 2 This is a schematic diagram illustrating the magnetic recording device according to the first embodiment.

[0010] Figure 3 (a)~ Figure 3 (d) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0011] Figure 4 (a) and Figure 4 (b) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0012] Figure 5 (a)~ Figure 5 (e) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

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

[0014] Figure 7 (a) and Figure 7 (b) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0015] Figure 8 This is a flowchart illustrating the operation of the magnetic recording device according to the first embodiment.

[0016] Fig. 9 (a) and Fig. 9 (b) is a schematic cross-sectional view illustrating a part of the magnetic recording device according to the first embodiment.

[0017] Fig.10 This is a flowchart illustrating the magnetic recording method according to the second embodiment.

[0018] Fig.11 It is a schematic perspective view illustrating a magnetic recording device according to an embodiment.

[0019] Fig.12 It is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0020] Fig.13 It is a schematic perspective view illustrating a magnetic recording device according to an embodiment.

[0021] Fig.14 (a) and Fig.14 (b) is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0022] Description of symbols

[0023] 20 magnetic element; 21, 22 first magnetic layer, second magnetic layer; 25a first magnetic pole side non-magnetic layer; 25b second magnetic pole side non-magnetic layer; 25n first non-magnetic layer; 30F magnetic pole surface; 30c coil; 30i insulating portion; 31 first magnetic pole; 32 second magnetic pole; 33 shield; 51 to 53 first circuit to third circuit; 54 control portion; 60 recording portion; 70 reproducing portion; 71 magnetic reproducing element; 72a, 72b first reproducing magnetic shield, second reproducing magnetic shield; 80 magnetic recording medium; 81 magnetic recording layer; 82 medium substrate; 83 magnetization; 85 medium moving direction; θ1 angle; 110, 111 magnetic head; 150 magnetic recording device; 154 suspension; 155 arm; 1 56 voice coil motor; 157 bearing unit; 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 unit; 210 magnetic recording device; AR arrow; C1, C2 first coil terminal, second coil terminal; CF1~CF5 first configuration~5th configuration; D1 direction; Id element current; Id_ave average value; Iw coil current; Iw-, Tw+ current; Lv1~Lv3 first value~3rd value; Rx resistance; ST1, ST2 state; SigR electrical signal;

[0024] T1, T2 1st terminal, 2nd terminal; W1, W2 1st wiring, 2nd wiring; f1 1st frequency; t1~t5 1st~5th cycle; td1 time difference; tm time; tw1 time width DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0026] The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the size between parts, etc. are not necessarily the same as the actual ones. Even when the same parts are shown, the mutual sizes and ratios may be shown differently depending on the drawings.

[0027] In the present specification and each drawing, the same reference numerals are given to the same elements as those described previously with reference to the drawings in which they appear, and detailed descriptions thereof are appropriately omitted.

[0028] (First embodiment)

[0029] Figure 1 This is a schematic cross-sectional view illustrating the magnetic recording device according to the first embodiment.

[0030] Figure 2 This is a schematic diagram illustrating the magnetic recording device according to the first embodiment.

[0031] like Figure 1 and Figure 2 As shown, the magnetic recording device 210 according to the embodiment includes a magnetic head 110 , a first circuit 51 , a second circuit 52 , a third circuit 53 , and a control unit 54 .

[0032] like Figure 1 As shown, the magnetic head 110 includes a first magnetic pole 31 , a second magnetic pole 32 , a magnetic element 20 , and a coil 30 c .

[0033] like Figure 1 As shown, the magnetic head 110 may be further provided with a shield 33. The first magnetic pole 31, the second magnetic pole 32, the magnetic element 20, the coil 30c, and the shield 33 are included in the recording unit 60. As described later, the magnetic head 110 may be provided with a reproducing unit.

[0034] The first magnetic pole 31 is provided between the shield 33 and the second magnetic pole 32. For example, at least a portion of the coil 30c is provided between the first magnetic pole 31 and the second magnetic pole 32. In this example, a portion of the coil 30c is provided between the shield 33 and the first magnetic pole 31.

[0035] The first circuit 51 is electrically connected to the coil 30c. The first circuit 51 can supply a coil current Iw to the coil 30c. In the recording operation, the coil current Iw is, for example, a recording current. A magnetic field (recording magnetic field) corresponding to the recording current is generated from the first magnetic pole 31. The recording magnetic field is applied to the magnetic recording medium 80, and information is recorded in the magnetic recording medium 80. In this way, the first circuit 51 can supply a recording current corresponding to the recorded information to the coil 30c. For example, the magnetic recording medium 80 is a perpendicular magnetic recording medium.

[0036] like Figure 1 As shown, a first coil terminal C1 and a second coil terminal C2 may be provided. These terminals are electrically connected to the coil 30c. For example, the first circuit 51 supplies a coil current Iw (for example, a recording current) to the coil 30c via these terminals.

[0037] like Figure 1 As shown, the magnetic element 20 is disposed between the first magnetic pole 31 and the second magnetic pole 32. The magnetic element 20 includes a first magnetic layer 21.

[0038] like Figure 1 As shown, for example, an insulating portion 30 i is provided around the first magnetic pole 31 , the second magnetic pole 32 , the shield 33 , the coil 30 c , and the magnetic element 20 .

[0039] The first magnetic pole 31 is, for example, a main magnetic pole. A magnetic pole surface 30F is provided at the end of the first magnetic pole 31. The magnetic pole surface 30F is, for example, along the ABS (Air Bearing Surface) of the magnetic head 110. The magnetic pole surface 30F faces the magnetic recording medium 80.

[0040] The direction perpendicular to the magnetic pole surface 30F is referred to as the Z-axis direction. A direction perpendicular to the Z-axis direction is referred to as the X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is referred to as the Y-axis direction.

[0041] The Z-axis direction is, for example, a height direction, the X-axis direction is, for example, a down track direction, and the Y-axis direction is a cross track direction.

[0042] For example, near the magnetic pole surface 30F, the second magnetic pole 32 is separated from the first magnetic pole 31 along the X-axis direction. The magnetic head 110 and the magnetic recording medium 80 are relatively moved substantially along the X-axis direction. Thus, information is recorded at an arbitrary position of the magnetic recording medium 80.

[0043] The second magnetic pole 32 corresponds to, for example, a "trailing shield". The shield 33 corresponds to, for example, a "leading shield". The second magnetic pole 32 is, for example, an auxiliary magnetic pole. The second magnetic pole 32 can form a magnetic core together with the first magnetic pole 31. For example, an additional shield such as a side shield (not shown) may also be provided.

[0044] like Figure 1 As shown, the second circuit 52 can supply the element current Id to the magnetic element 20 .

[0045] For example, the magnetic element 20 may be electrically connected to the first magnetic pole 31 and the second magnetic pole 32. In this case, the element current Id may be supplied to the magnetic element 20 via the first magnetic pole 31 and the second magnetic pole 32.

[0046] like Figure 1 As shown, a first wiring W1 and a second wiring W2 may also be provided. The first wiring W1 is electrically connected to the first magnetic pole 31. The second wiring W2 is electrically connected to the second magnetic pole 32. A first terminal T1 and a second terminal T2 may also be provided. The first terminal T1 is electrically connected to the first magnetic pole 31 via the first wiring W1. The second terminal T2 is electrically connected to the second magnetic pole 32 via the second wiring W2.

[0047] For example, the element current Id is supplied from the second circuit 52 to the first magnetic pole 31 and the second magnetic pole 32 via the first terminal T1 , the first wiring W1 , the second wiring W2 , and the second terminal T2 .

[0048] In the embodiment, by flowing the element current Id in the magnetic element 20, the magnetic field emitted from the first magnetic pole 31 can be efficiently directed toward the magnetic recording medium 80. For example, by the element current Id, the direction of magnetization of the first magnetic layer 21 is reversed relative to the magnetic field emitted from the first magnetic pole 31. It becomes difficult for the magnetic field emitted from the first magnetic pole 31 to pass through the first magnetic layer 21. As a result, it becomes easy for the magnetic field to be directed toward the magnetic recording medium 80. As a result, the magnetic field is efficiently applied to the magnetic recording medium 80. By such an action, the recording density can be improved.

[0049] As described later, the magnetic element 20 may also include a second magnetic layer. In this case, the element current Id is supplied to the magnetic element 20, for example, the magnetic element 20 oscillates. The magnetic element 20 functions as an STO (Spin Torque Oscillator). Along with the oscillation, an AC magnetic field (for example, a high-frequency magnetic field) is generated from the magnetic element 20. The AC magnetic field generated by the magnetic element 20 is applied to the magnetic recording medium 80, and the recording to the magnetic recording medium 80 is assisted. For example, MAMR (Microwave Assisted Magnetic Recording) can be implemented. In this case, the recording density can also be improved.

[0050] The third circuit 53 (see Figure 2 ) can detect the resistance of the magnetic element 20. The third circuit 53 is electrically connected to the first terminal T1 and the second terminal T2, for example. The third circuit 53 can also detect at least one of the resistance of the magnetic element 20 and the change in the resistance of the magnetic element 20 via at least a portion of the second circuit 52. The third circuit 53 detects the electrical signal SigR obtained from the magnetic element 20. The third circuit 53 can detect the resistance of the magnetic element 20 based on the electrical signal SigR.

[0051] As described above, in one example, the direction of magnetization of the first magnetic layer 21 is reversed relative to the magnetic field emitted from the first magnetic pole 31 by the element current Id. As a result, the resistance of the magnetic element 20 changes. In other examples, for example, the magnetization of the first magnetic layer 21 oscillates by the element current Id. The resistance of the magnetic element 20 changes by the element current Id. By detecting the resistance (or the change in resistance), information related to the magnetic state in the magnetic element 20 can be obtained. For example, the state of magnetization reversal in the magnetic element 20 can be grasped. For example, the state of magnetization oscillation in the magnetic element 20 can be grasped.

[0052] The control unit 54 can control the second circuit 52 based on the resistance detected by the third circuit 53 , thereby controlling the element current Id.

[0053] For example, the control unit 54 controls the element current Id so that the resistance becomes higher. For example, when the magnetization of the magnetic element 20 is reversed, the resistance of the magnetic element 20 becomes higher than the resistance before the magnetization reversal of the magnetic element 20. For example, when the resistance becomes the highest, the degree of magnetization reversal is high in the magnetic element 20 relative to the magnetic field of the recording magnetic field. For example, when the resistance becomes the highest, the recording magnetic field can be efficiently directed toward the magnetic recording medium 80. Thus, the recording density can be improved. A magnetic recording device that can improve recording capacity can be provided.

[0054] like Figure 2 As shown, the third circuit 53 (e.g., a detection circuit) obtains the electrical signal SigR from the magnetic element 20 and detects the resistance based on the electrical signal SigR. The detected resistance Rx is provided to the control unit 54. The control unit 54 controls the second circuit 52 based on the resistance Rx, thereby controlling the element current Id. As described later, for example, the electrical signal SigR detected by the third circuit 53 changes temporally corresponding to the temporal change of the coil current Iw. The resistance Rx can be an average of the resistance corresponding to the electrical signal SigR that changes temporally.

[0055] Hereinafter, examples of the coil current Iw and the element current Id will be described.

[0056] Figure 3 (a)~ Figure 3 (d) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0057] The horizontal axis of these graphs is time tm. Figure 3 The vertical axis of (a) is the coil current Iw. Figure 3 (b)~ Figure 3 The vertical axis of (d) is the element current Id. Next, an example of an operation (first operation) performed in the magnetic recording device 210 is described. As already described, the coil current Iw is controlled by the first circuit 51, and the element current Id is controlled by the second circuit 52.

[0058] like Figure 3 As shown in (a), at the first moment t1, the polarity of the coil current Iw changes. For example, the coil current Iw is an alternating current. In this example, the alternating current has a first frequency f1. For example, the coil current Iw changes between a current Iw- and a current Iw+.

[0059] like Figure 3As shown in (b), in one example, the element current Id is the first value Lv1. The first value Lv1 is positive. For example, when the first value Lv1 is large, the magnetization changes quickly, and high performance is easily obtained. When the first value Lv1 is excessively large, the magnetic element 20 is easily damaged. For example, regarding the case where the element current Id is constant at the first value Lv1, an "upper limit value" is determined for maintaining a stable magnetic element 20. The control unit 54 may also be able to control the second circuit 52 based on the resistance Rx detected by the third circuit 53, thereby controlling the first value Lv1 of the element current Id. In this case, the first value Lv1 is set to be below the above-mentioned "upper limit value".

[0060] like Figure 3 As shown in (c), in one example, the second circuit 52 sets the element current Id to the first value Lv1 before the second time t2. The second circuit 52 changes the element current Id to the second value Lv2 at the second time t2. The second value Lv2 is different from the first value Lv1. Figure 3 In the example shown in (b), the second time t2 is after the first time t1. The second circuit 52 changes the element current Id to the first value Lv1 at a third time t3 after the second time t2.

[0061] For example, the second time t2 can be practically the time when the element current Id becomes the intermediate value between the value before the change (the first value Lv1) and the value after the change (the second value Lv2). The third time t3 can also be the time when the element current Id becomes the intermediate value between the value before the change (the second value Lv2) and the value after the change (the first value Lv1).

[0062] When the element current Id has such a waveform, in the first action, the control unit 54 can control the second circuit 52 based on the resistance Rx detected by the third circuit 53, thereby controlling at least any one of the second time t2, the third time t3, the first value Lv1, and the second value Lv2.

[0063] In the above operation, the time average of the device current Id is set to be constant when the device current Id is constant (for example Figure 3 The time average of the element current Id corresponds to "the time proportion of the element current Id being the first value Lv1" × Lv1 + "the time proportion of the element current Id being the second value Lv2" × Lv2. Figure 3 The first value LV1 in (b) Figure 3 The first value Lv1 in (c) and Figure 3 The first value Lv1 in (d) may be different from each other. Figure 3 The second value Lv2 in (c) and Figure 3The second value Lv2 in (d) may be different from each other.

[0064] The second time t2 may be, for example, a time based on the first time t1. The third time t3 may be, for example, a time based on the first time t1. The third time t3 may be, for example, a time based on the second time t2.

[0065] The control unit 54 controls at least one of the second time t2, the third time t3, the first value Lv1, and the second value Lv2 based on the detected resistance Rx, so that the resistance Rx becomes higher. As a result, for example, in the magnetic element 20, the magnetization is effectively reversed. Or, for example, in the magnetic element 20, the magnetization is effectively oscillated. For example, the recording magnetic field effectively acts on the magnetic recording medium 80. A high recording density can be obtained.

[0066] exist Figure 3 In the example shown in (c), the second circuit 52 also makes the element current Id the first value Lv1 before the second time t2, changes the element current Id to the second value Lv2 at the second time t2, and changes the element current Id to the first value Lv1 at the third time t3. Figure 3 As shown in (c), the second circuit 52 further changes the element current Id to the third value Lv3 at the fourth time t4 before the second time t2. The third value Lv3 is different from the first value Lv1 and also different from the second value Lv2. The second circuit 52 starts to change the element current Id to the second value Lv2 at the fifth time t5 after the fourth time t4 and before the second time t2.

[0067] The control unit 54 controls at least one of the second moment t2, the third moment t3, the fourth moment t4, the fifth moment t5, the first value Lv1, the second value Lv2, and the third value Lv3 based on the detected resistance Rx, so that the resistance Rx becomes higher. As a result, for example, in the magnetic element 20, the magnetization is effectively reversed. Or, for example, in the magnetic element 20, the magnetization is effectively oscillated. For example, the recording magnetic field effectively acts on the magnetic recording medium 80. A high recording density can be obtained.

[0068] In the above operation, the time average of the device current Id is set to be constant when the device current Id is constant (for example Figure 3 The time average of the element current Id corresponds to "the time proportion that the element current Id is the first value Lv1" × "the absolute value of Lv1" + "the time proportion that the element current Id is the second value Lv2" × "the absolute value of Lv2" + "the time proportion that the element current Id is the third value Lv3" × "the absolute value of Lv3".

[0069] Hereinafter, an example of the electric signal SigR obtained from the magnetic element 20 will be described.

[0070] Figure 4 (a) and Figure 4 (b) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0071] Figure 4 (a) illustrates the coil current Iw. Figure 4 (b) shows an example of the electric signal SigR obtained from the magnetic element 20. The electric signal SigR corresponds to the resistance of the magnetic element 20. The horizontal axis of these graphs represents the time tm. Figure 4 The vertical axis of (a) is the coil current Iw. Figure 4 The vertical axis of (b) is the electric signal SigR obtained from the magnetic element 20 .

[0072] like Figure 4 As shown in (a), for example, the coil current Iw is an alternating current having a first frequency f1. Figure 4 As shown in (b) of FIG. 8 , the electric signal SigR has a second frequency that is twice the first frequency f1.

[0073] exist Figure 4 In the characteristic illustrated in (b), the state ST1 in which the electric signal SigR is relatively low corresponds to the state before the magnetization of the magnetic element 20 is reversed. The state ST2 in which the electric signal SigR is relatively high corresponds to the state in which the magnetization of the magnetic element 20 is reversed. For example, when the magnetization of the magnetic element 20 is reversed in a short time, the state ST1 is quickly changed to the state ST2. As already explained, the control unit 54 controls the second circuit 52 based on the resistance Rx detected by the third circuit 53. The resistance Rx corresponds to the temporal average of the electric signal SigR, for example. For example, the resistance Rx can also be related to the Figure 4 It corresponds to the value obtained by integrating and averaging the electrical signal SigR illustrated in (b).

[0074] Based on such resistance Rx, the control unit 54 controls at least any one of the second moment t2, the third moment t3, the first value Lv1, and the second value Lv2 so that the resistance Rx becomes higher. It can be seen that in the magnetic recording device 210, by using the element current Id including the first value Lv1, the second value Lv2, and the third value Lv3 as described above, it is easy to obtain a high resistance Rx. Below, an example of the change in the resistance of the magnetic element 20 is described.

[0075] Figure 5 (a)~ Figure 5 (e) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0076] In these drawings, the horizontal axis represents time tm. Figure 5 (a) shows an example of the coil current Iw. At the first time t1, the polarity of the coil current Iw changes. Figure 5 (b) shows an example of the element current Id in the first configuration CF1. Figure 5 As shown in (b) of FIG. 8 , in the first configuration CF1 , the element current Id is always the first value Lv1 .

[0077] Figure 5 (c) shows an example of the element current Id in the second configuration CF2. Figure 5 As shown in (c), in the second configuration CF2, the difference between the first time t1 and the second time t2 is 0. In the second configuration CF2, the difference between the second time t2 and the third time t3 (ie, the time width tw1) is 0.4 ns.

[0078] Figure 5 (d) shows an example of the element current Id in the third configuration CF3 and the fourth configuration CF4. Figure 5 As shown in (d), in the third configuration CF3 and the fourth configuration CF4, the second moment t2 is after the first moment t1. In the third configuration CF3, the difference between the first moment t1 and the second moment t2 (time difference td1) is 0.2ns. In the fourth configuration CF4, the difference between the first moment t1 and the second moment t2 (time difference td1) is 0.4ns. In the third configuration CF3 and the fourth configuration CF4, the difference between the second moment t2 and the third moment t3 (i.e., time width tw1) is 0.4ns.

[0079] Figure 5 (e) shows an example of the element current Id in the fifth configuration CF5. Figure 5 As shown in (e), in the fifth configuration CF5, the second moment t2 is before the first moment t1. In the fifth configuration CF5, the difference between the first moment t1 and the second moment t2 (time difference td1) is -0.2ns. In the fifth configuration CF5, the difference between the second moment t2 and the third moment t3 (i.e., time width tw1) is 0.4ns. When the time average of the element current Id is the same, Figure 5 The first value Lv1 in (b) is Figure 5 (c)~ Figure 5 The first value Lv1 in (e) is different.

[0080] The resistors Rx of the first configuration CF1 to the fifth configuration CF5 are evaluated. In the evaluation, the average value (time average) of the element current Id is changed. The change of the average value of the element current Id is performed by changing the first value Lv1 and the second value Lv2.

[0081] Figure 6 This is a graph illustrating the characteristics of the magnetic recording device according to the first embodiment.

[0082] exist Figure 6 In FIG. 1 , the horizontal axis is the average value Id_ave of the element current Id. The vertical axis is the resistance Rx of the magnetic element 20. The resistance Rx corresponds to the temporal average value of the electrical signal SigR that changes with time. Figure 6 In the example, a high resistance Rx indicates that the magnetization is effectively changing (eg, reversing).

[0083] like Figure 6 As shown, for the same average value Id_ave of the element current Id, the resistor Rx in the third configuration CF3 and the fourth configuration CF4 is higher than the resistor Rx in the other configurations. When the average value Id_ave is relatively large, the resistor Rx in the second configuration CF2 is higher than the resistor Rx in the first configuration CF1. The resistor Rx in the fifth configuration CF5 is lower than the resistor Rx in the first configuration CF1.

[0084] The reason why high resistance Rx can be obtained in the third configuration CF3 and the fourth configuration CF4 is considered to be related to the following situation: the magnetization reversal of the magnetic element 20 is accelerated by increasing the element current Id just after the magnetic pole is reversed due to the reversal of the coil current Iw.

[0085] In this way, by controlling the waveform of the element current Id, a high resistance Rx can be obtained. By appropriately controlling the element current Id by the control unit 54, a higher resistance Rx can be obtained, and more effective magnetization control can be achieved. By controlling at least one of the second time t2, the third time t3, the first value Lv1, and the second value Lv2 by the control unit 54, more effective magnetization control can be achieved.

[0086] In the embodiment, the time difference td1 is preferably positive. In the period of 1 / 2 of the cycle of the coil current Iw, the second time t2 is preferably after the first time t1. The difference between the first time t1 and the second time is preferably, for example, 0.1 ns or more and 1 ns or less.

[0087] exist Figure 3 In the waveform illustrated in (c), the resistance Rx also changes according to the condition of the element current Id. By appropriately controlling the element current Id by the control unit 54, a higher resistance Rx can be obtained, and more effective magnetization control can be achieved. By controlling at least any one of the second moment t2, the third moment t3, the fourth moment t4, the fifth moment t5, the first value Lv1, the second value Lv2, and the third value Lv3 by the control unit 54, more effective magnetization control can be achieved.

[0088] In the embodiment, for example, during 1 / 2 of the cycle of the coil current Iw, the time when the element current Id is the first value Lv1 is longer than the time when the element current Id is the second value Lv2. The magnetization changes more effectively by the short pulse-shaped second value Lv2. During 1 / 2 of the cycle of the coil current Iw, the time when the element current Id is the first value Lv1 is longer than the time when the element current Id is the third value Lv3. The magnetization changes more effectively by the short pulse-shaped third value Lv3.

[0089] Figure 7 (a) and Figure 7 (b) is a schematic diagram illustrating the operation of the magnetic recording device according to the first embodiment.

[0090] These figures show other examples of the element current Id. In these figures, the horizontal axis represents time tm. Figure 7 The vertical axis of (a) is the coil current Iw. Figure 7 The vertical axis of (b) is the device current Id.

[0091] like Figure 7 As shown in (a), at the first moment t1, the polarity of the coil current Iw changes. Figure 7 In the example shown in (b), the second circuit 52 also makes the element current Id the first value Lv1 before the second moment t2. The second circuit 52 makes the element current Id the second value Lv2 at the second moment t2. At the fourth moment t4 after the second moment t2 and before the third moment t3, the element current Id is changed to the third value Lv3. At the third moment t3, the element current Id is changed to the first value Lv1. The third value Lv3 is between the first value Lv1 and the second value Lv2.

[0092] exist Figure 7 In the waveform illustrated in (b), more effective magnetization control can be achieved by controlling at least any one of the second time t2, the third time t3, the fourth time t4, the first value Lv1, the second value Lv2, and the third value Lv3 by the control unit 54.

[0093] Figure 8 This is a flowchart illustrating the operation of the magnetic recording device according to the first embodiment.

[0094] Figure 8 An example of the operation of the control unit 54 and the operation of the second circuit 52 and the third circuit 53 performed under the control of the control unit 54 is shown.

[0095] like Figure 8 As shown, the third circuit 53 detects the resistance Rx of the magnetic element 20 (step S101). The control unit 54 determines the average value Id_ave of the element current Id (step S102).

[0096] The control unit 54 sets the first value Lv1 and the second value Lv2 of the element current Id (step S105 ). The control unit 54 may further determine a third value Lv3 .

[0097] The control unit 54 sets the second time t2 and the third time t3 (step S106). The control unit 54 may further determine the fourth time t4. The control unit 54 may further determine the fifth time t5.

[0098] The third circuit 53 detects the resistor Rx with respect to the second element current Id having the determined value and timing (step S210 ).

[0099] The control unit 54 determines whether the difference between the detected resistance Rx and the previous detection value (the resistance Rx detected last time) is less than the determined value (the first threshold value) (step S211). If the difference is not less than the first threshold value, the process returns to step S106. In step S106, the second time t2 and the third time t3 are updated. In the update, the second time t2 and the third time t3 are set so that the resistance Rx becomes higher while maintaining the determined average value Id_ave of the element current Id. Steps S210 and S211 are repeated.

[0100] In step S211, when the difference is below the first threshold, proceed to step S212. In step S212, determine whether the difference between the detected resistance Rx and the previous detection value (previous detected resistance Rx) is below the determined value (second threshold). If the difference is not below the second threshold, return to step S105. In step S105, the values ​​of the first value Lv1 and the second value Lv2 are updated. In the update, the first value Lv1 and the second value Lv2 are set so that the resistance Rx becomes higher while maintaining the determined average value Id_ave of the element current Id. Repeat steps S106 to S212.

[0101] In step S212, when the difference is below the second threshold value, the resistance Rx becomes substantially the highest at this "value" and "moment". For example, a recording operation (step S220) is performed by using the element current Id having such a "value" and "moment". In the recording operation, the recording magnetic field acts efficiently on the magnetic recording medium 80. For example, a high recording density can be obtained. A magnetic recording device that can improve recording capacity can be provided.

[0102] exist Figure 8 In the process, it is also possible to set the "time" in step S105 and set the "value" in step S106.

[0103] Hereinafter, an example of the magnetic head 110 in the magnetic recording device 210 according to the embodiment will be described.

[0104] Fig. 9 (a) and Fig. 9 (b) is a schematic cross-sectional view illustrating a part of the magnetic recording device according to the first embodiment.

[0105] like Fig. 9 As shown in (a), in the magnetic head 110, the magnetic element 20 may also include a first magnetic pole side non-magnetic layer 25a and a second magnetic pole side non-magnetic layer 25b in addition to the first magnetic layer 21. The first magnetic pole side non-magnetic layer 25a is arranged between the first magnetic pole 31 and the first magnetic layer 21. The second magnetic pole side non-magnetic layer 25b is arranged between the first magnetic layer 21 and the second magnetic pole 32.

[0106] In one example, the first magnetic pole side non-magnetic layer 25a includes a first material, and the second magnetic pole side non-magnetic layer 25b includes a second material. The first material includes, for example, at least one selected from Ta, Pt, W, Ir, Mo, Cr, Tb, Mn, and Ni. The second material includes, for example, at least one selected from Cu, Ag, Au, Cr, and Ru. In this case, when the element current Id is the first value Lv1, the element current Id has a first direction from the second magnetic pole 32 toward the first magnetic pole 31. Appropriate magnetization reversal can be obtained.

[0107] In another example, the first magnetic pole side non-magnetic layer 25a may include the second material, and the second magnetic pole side non-magnetic layer 25b may include the first material. In this case, the element current Id when the element current Id is the first value Lv1 has a second direction from the first magnetic pole 31 toward the second magnetic pole 32. Appropriate magnetization reversal can be obtained.

[0108] In the magnetic recording device 210 including the magnetic head 110, the control unit 54 may not be provided. For example, the condition of the element current Id may be set so that the resistance Rx becomes higher. In this case, the magnetic recording device 210 includes the magnetic head 110, the first circuit 51 capable of supplying the coil current Iw to the coil 30c, and the second circuit 52 capable of supplying the element current Id to the magnetic element 20. At the first moment t1, the polarity of the coil current Iw changes. The second circuit 52 makes the element current Id the first value Lv1 before the second moment t2, and the second circuit 52 changes the element current Id to the second value Lv2 different from the first value Lv1 at the second moment t2. At the third moment t3 after the second moment t2, the element current Id is changed to the first value Lv1. The second moment t2 is preferably after the first moment t1.

[0109] In the above operation, the second circuit 52 may change the element current Id to a third value Lv3 different from the first value Lv1 and also different from the second value Lv2 at a fourth time t4 before the second time t2 (see Figure 3 The second circuit 52 may also change the element current Id to the second value Lv2 at a fifth time t5 after the fourth time t4 and before the second time t2 (see Figure 3 (c)). For example, the first value Lv1 is between the third value Lv3 and the second value Lv2.

[0110] like Fig. 9 As shown in (b), in the magnetic head 111, the magnetic element 20 includes a second magnetic layer 22 and a first non-magnetic layer 25n in addition to the first magnetic layer 21. The second magnetic layer 22 is provided between the first magnetic layer 21 and the first magnetic pole 31. The first non-magnetic layer 25n is provided between the first magnetic layer 21 and the second magnetic layer 22. In this case, the magnetic element 20 functions as an STO element, for example.

[0111] like Fig. 9 As shown in (b), in the magnetic head 111, the magnetic element 20 may also include a first magnetic pole side non-magnetic layer 25a and a second magnetic pole side non-magnetic layer 25b. The first magnetic pole side non-magnetic layer 25a is arranged between the first magnetic pole 31 and the second magnetic layer 22. The second magnetic pole side non-magnetic layer 25b is arranged between the first magnetic layer 21 and the second magnetic pole 32.

[0112] In the magnetic head 111, for example, the first magnetic pole side non-magnetic layer 25a and the second magnetic pole side non-magnetic layer 25b include the first material, and the first non-magnetic layer 25n includes the second material. The first material includes, for example, at least one selected from Ta, Pt, W, Ir, Mo, Cr, Tb, Mn and Ni. The second material includes, for example, at least one selected from Cu, Ag, Au, Cr and Ru. The direction of the element current Id when the element current Id is the first value Lv1 may also be any direction of the first direction from the first magnetic pole 31 toward the second magnetic pole 32 and the second direction from the second magnetic pole 32 toward the first magnetic pole 31. Appropriate magnetization oscillation can be obtained.

[0113] In the magnetic recording device 210 including the magnetic head 111, the control unit 54 may not be provided. For example, the condition of the element current Id may be set so that the resistance Rx becomes high. In this case, the magnetic recording device 210 includes the magnetic head 111, the first circuit 51, and the second circuit 52. The second circuit 52 supplies, for example, the magnetic element 20 with a current Id. Figure 3. For example, the second circuit 52 causes the element current Id to be the first value Lv1 before the second moment t2. The second circuit 52 changes the element current Id to the second value Lv2 at the second moment t2. The second circuit 52 changes the element current Id to the first value Lv1 at the third moment t3 after the second moment t2. The second circuit 52 changes the element current Id to the third value Lv3 that is different from the first value Lv1 and also different from the second value Lv2 at the fourth moment t4 before the second moment t2. The second circuit 52 changes the element current Id to the second value Lv2 at the fifth moment t5 after the fourth moment t4 and before the second moment t2.

[0114] like Fig. 9 (a) and Fig. 9 As shown in (b), the direction D1 from the first magnetic pole 31 toward the second magnetic pole 32 may also be inclined relative to the X-axis direction. The direction D1 corresponds to the stacking direction of the magnetic element 20. The X-axis direction is along the magnetic pole surface 30F of the first magnetic pole 31. The angle between the direction D1 and the magnetic pole surface 30F is set to angle θ1. The angle θ1 is, for example, greater than 15 degrees and less than 30 degrees. The angle θ1 may also be 0 degrees.

[0115] (Second embodiment)

[0116] The second embodiment relates to a magnetic recording method. The magnetic head 110 will be described below. The magnetic recording method can also be applied to the magnetic head 111.

[0117] Fig.10 This is a flowchart illustrating the magnetic recording method according to the second embodiment.

[0118] like Fig.10 As shown, in the magnetic recording method involved in the embodiment, the resistance Rx of the magnetic element 20 is detected (step S110). The magnetic element 20 is arranged in the magnetic head 110 including the first magnetic pole 31, the second magnetic pole 32, the magnetic element 20 and the coil 30c. The magnetic element 20 is arranged between the first magnetic pole 31 and the second magnetic pole 32. The magnetic element 20 includes a first magnetic layer 21. The detection may also include: supplying a coil current Iw to the coil 30c, and supplying an element current Id to the magnetic element 20. The detection may also include, for example, calculating the average value of the cumulative value of the electrical signal SigR obtained from the magnetic element 20. For example, the average value corresponds to the resistance Rx.

[0119] like Fig.10 As shown, in the magnetic recording method, the element current Id is controlled based on the result of detecting the resistance Rx of the magnetic element 20 (step S120). For example, the element current Id is controlled so that the resistance Rx becomes higher. A magnetic recording method that can improve recording capability can be provided.

[0120] As about Figure 3 As described in (a) of FIG. 1 , at the first moment t1, the polarity of the coil current Iw changes. Figure 3 As described in (b), before the second moment t2, the element current Id is set to the first value Lv1. At the second moment t2, the element current Id is changed to the second value Lv2 different from the first value Lv1. At the third moment t3 after the second moment t2, the element current Id is changed to the first value Lv1. Based on the result obtained by detecting the resistance Rx of the magnetic element 20, at least any one of the second moment t2, the third moment t3, the first value Lv1 and the second value Lv2 is controlled.

[0121] You can also use About Figure 3 (c) of the present invention. For example, at the fourth moment t4 before the second moment t2, the element current Id is changed to the third value Lv3 which is different from the first value Lv1 and also different from the second value Lv2. At the fifth moment t5 after the fourth moment t4 and before the second moment t2, the element current Id is changed to the second value Lv2. Based on the detected resistance Rx, at least any one of the second moment t2, the third moment t3, the fourth moment t4, the fifth moment t5, the first value Lv1, the second value Lv2 and the third value Lv3 is controlled.

[0122] For example, the first value Lv1 is between the third value Lv3 and the second value Lv2. For example, the absolute value of the difference between the first value Lv1 and the second value Lv2 is greater than the absolute value of the difference between the first value Lv1 and the third value Lv3. For example, the first value Lv1 is one of positive and negative. The second value Lv2 is the other of positive and negative. For example, the second moment t2 may be the moment when the polarity of the element current Id changes in practical terms. The third moment t3 may be the moment when the polarity of the element current Id changes in practical terms.

[0123] In the magnetic recording method, for example, the coil current Iw is an alternating current having a first frequency f1. The detection of the resistance Rx of the magnetic element 20 may include: detecting the electric signal SigR obtained from the magnetic element 20. The electric signal SigR has, for example, a second frequency that is twice the first frequency f1. For example, the resistance Rx corresponds to the temporal average of the electric signal SigR.

[0124] In the magnetic recording method according to the embodiment, it is also possible to apply Figure 7 The element current Id illustrated in (b).

[0125] Fig.11 It is a schematic perspective view illustrating a magnetic recording device according to an embodiment.

[0126] like Fig.11As shown, the magnetic head (e.g., magnetic head 110) according to the embodiment is used together with a magnetic recording medium 80. In this example, the magnetic head 110 includes a recording unit 60 and a reproducing unit 70. Information is recorded in the magnetic recording medium 80 by the recording unit 60 of the magnetic head 110. The information recorded in the magnetic recording medium 80 is reproduced by the reproducing unit 70.

[0127] The magnetic recording medium 80 includes, for example, a dielectric substrate 82 and a magnetic recording layer 81 provided on the dielectric substrate 82. The magnetization 83 of the magnetic recording layer 81 is controlled by the recording unit 60.

[0128] 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 provided between the first reproduction magnetic shield 72a and the second reproduction magnetic shield 72b. The magnetic reproduction element 71 can output a signal corresponding to the magnetization 83 of the magnetic recording layer 81.

[0129] like Fig.11 As shown, the magnetic recording medium 80 moves relative to the magnetic head 110 in the medium moving direction 85. The information corresponding to the magnetization 83 of the magnetic recording layer 81 is controlled at an arbitrary position by the magnetic head 110. The information corresponding to the magnetization 83 of the magnetic recording layer 81 is reproduced at an arbitrary position by the magnetic head 110.

[0130] Hereinafter, an example of the magnetic recording device according to the present embodiment will be described.

[0131] Fig.12 It is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0132] Fig.12 A head slider is illustrated.

[0133] The magnetic head 110 (or the magnetic head 111) is provided on a head slider 159. The head slider 159 includes, for example, Al 2 O 3 / TiC, etc. The head slider 159 moves relative to the magnetic recording medium while floating above the magnetic recording medium or in contact with the magnetic recording medium.

[0134] The head slider 159 includes, 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 the magnetic recording medium.

[0135] Fig.13 It is a schematic perspective view illustrating a magnetic recording device according to an embodiment.

[0136] like Fig.13 As shown, a rotary actuator is used in the magnetic recording device 150 involved in the embodiment. The recording medium disk 180 is arranged on the spindle motor 180M. The recording medium disk 180 is rotated in the direction of the arrow AR by the spindle motor 180M. The spindle motor 180M responds to the control signal from the drive device control unit. The magnetic recording device 150 involved in this embodiment may also 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 the recording medium 181, a non-volatile memory such as a flash memory is used. For example, the magnetic recording device 150 may also be a hybrid HDD (Hard Disk Drive).

[0137] The head slider 159 records and reproduces information recorded on the recording medium disk 180. The head slider 159 is provided at the front end of the thin film suspension 154. The magnetic head according to the embodiment is provided near the front end of the head slider 159.

[0138] When the recording medium disk 180 rotates, the pressing pressure generated by the suspension 154 and the pressure generated on the medium facing surface (ABS) of the head slider 159 are balanced. The distance between the medium facing surface of the head slider 159 and the surface of the recording medium disk 180 becomes a predetermined suspension amount. In the embodiment, the head slider 159 may also contact the recording medium disk 180. For example, a contact travel type may also be applied.

[0139] The suspension 154 is connected to one end of an arm 155 (e.g., an actuator arm). The arm 155 includes, for example, a bobbin portion, etc. The bobbin portion holds a drive coil. A voice coil motor 156 is provided at the other end of the arm 155. The voice coil motor 156 is a type of linear motor. The voice coil motor 156 includes, for example, a drive coil and a magnetic circuit. The drive coil is wound around the bobbin portion of the arm 155. The magnetic circuit includes a permanent magnet and an opposing yoke. A drive coil is provided between the permanent magnet and the opposing yoke. The suspension 154 includes one end and the other end. The magnetic head is provided at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0140] The arm 155 is held by a ball bearing. The ball bearings are provided at two locations, upper and lower, of the bearing portion 157. The arm 155 can be rotated and slid by the voice coil motor 156. The magnetic head can be moved to any position of the recording medium disk 180.

[0141] Fig.14 (a) and Fig.14(b) is a schematic perspective view illustrating a part of the magnetic recording device according to the embodiment.

[0142] Fig.14 (a) illustrates a structure of a portion of the magnetic recording device and is an enlarged perspective view of the head stack assembly 160 . Fig.14 (b) is a perspective view illustrating a magnetic head assembly (head gimbal assembly: HGA) 158 which is a part of the head stack assembly 160 .

[0143] like Fig.14 As shown in (a), the head stack assembly 160 includes a bearing portion 157, a head gimbal assembly 158, and a support frame 161. The head gimbal assembly 158 extends from the bearing portion 157. The support frame 161 extends from the bearing portion 157. The direction in which the support frame 161 extends is opposite to the direction in which the head gimbal assembly 158 extends. The support frame 161 supports the coil 162 of the voice coil motor 156.

[0144] like Fig.14 As shown in FIG. 1 (b), the head gimbal assembly 158 includes an arm 155 extending from a bearing portion 157 and a suspension 154 extending from the arm 155 .

[0145] A head slider 159 is provided at the front end of the suspension 154. The head slider 159 is provided with the magnetic head according to the embodiment.

[0146] The head assembly (head gimbal assembly) 158 according to the embodiment includes the magnetic head according to the embodiment, a head slider 159 provided with the magnetic head, a suspension 154, and an arm 155. The head slider 159 is provided at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.

[0147] The suspension 154 includes, for example, lead lines (not shown) for recording and reproducing signals. The suspension 154 may also include, for example, lead lines (not shown) for a heater for adjusting the suspension amount. The suspension 154 may also include, for example, lead lines (not shown) for a spin torque oscillator, etc. These lead lines are electrically connected to a plurality of electrodes provided on the magnetic head.

[0148] The magnetic recording device 150 is provided with a signal processing unit 190. The signal processing unit 190 records and reproduces signals on the magnetic recording medium using a magnetic head. The input and output lines of the signal processing unit 190 are connected to, for example, electrode pads of the head gimbal assembly 158 and are electrically connected to the magnetic head.

[0149] The magnetic recording device 150 involved in this embodiment includes a magnetic recording medium, a magnetic head involved in the embodiment, a movable part, a position control part and a signal processing part. The movable part can relatively move the magnetic recording medium and the magnetic head in a separated or contacted state. The position control part makes the magnetic head position match the predetermined recording position of the magnetic recording medium. The signal processing part records and reproduces the signal of the magnetic recording medium using the magnetic head.

[0150] For example, as the magnetic recording medium, a recording medium disk 180 may be used. The movable portion includes, for example, a head slider 159. The position control portion includes, for example, a head gimbal assembly 158.

[0151] The magnetic recording device 150 according to the present embodiment includes a magnetic recording medium, a magnetic head assembly according to the embodiment, and a signal processing unit that performs recording and reproduction of signals on the magnetic recording medium using a magnetic head provided in the magnetic head assembly.

[0152] Implementation methods may include the following technical solutions (eg, technical solutions).

[0153] (Technical Solution 1)

[0154] A magnetic recording device comprising:

[0155] A magnetic head, comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, wherein the magnetic element is arranged between the first magnetic pole and the second magnetic pole, and the magnetic element comprises a first magnetic layer;

[0156] a first circuit capable of supplying a coil current to the coil;

[0157] a second circuit capable of supplying an element current to the magnetic element;

[0158] a third circuit capable of detecting the resistance of the magnetic element; and

[0159] A control unit is configured to control the second circuit based on the resistance detected by the third circuit, thereby controlling the element current.

[0160] (Technical Solution 2)

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

[0162] The control unit can control the second circuit based on the resistance detected by the third circuit, thereby controlling the value of the element current.

[0163] (Technical Solution 3)

[0164] According to the magnetic recording device described in technical solution 1,

[0165] In the first action, the polarity of the coil current changes at the first moment.

[0166] In the first operation, the second circuit causes the element current to be a first value before a second moment, the second circuit causes the element current to change to a second value different from the first value at the second moment, and causes the element current to change to the first value at a third moment after the second moment.

[0167] In the first operation, the control unit may control the second circuit based on the resistance detected by the third circuit, thereby controlling at least one of the second time, the third time, the first value, and the second value.

[0168] (Technical Solution 4)

[0169] According to the magnetic recording device described in technical solution 3,

[0170] In the first operation, the second circuit changes the element current to a third value different from the first value and also different from the second value at a fourth time before the second time, and changes the element current to the second value at a fifth time after the fourth time and before the second time.

[0171] In the first action, the control unit can control the second circuit based on the resistance detected by the third circuit, thereby controlling at least any one of the second moment, the third moment, the fourth moment, the fifth moment, the first value, the second value and the third value.

[0172] (Technical Solution 5)

[0173] According to the magnetic recording device described in technical solution 4,

[0174] The first value is between the third value and the second value.

[0175] (Technical Solution 6)

[0176] According to the magnetic recording device described in technical solution 5,

[0177] An absolute value of a difference between the first value and the second value is greater than an absolute value of a difference between the first value and the third value.

[0178] (Technical Solution 7)

[0179] The magnetic recording device according to any one of technical solutions 1 to 6,

[0180] The magnetic element further comprises:

[0181] a first magnetic pole side non-magnetic layer provided between the first magnetic pole and the first magnetic layer; and

[0182] The second magnetic pole side non-magnetic layer is provided between the first magnetic layer and the second magnetic pole.

[0183] (Technical Solution 8)

[0184] According to the magnetic recording device described in technical solution 7,

[0185] In the case where the non-magnetic layer on the first magnetic pole side includes a first material and the non-magnetic layer on the second magnetic pole side includes a second material, the element current when the element current is the first value has a first direction from the second magnetic pole toward the first magnetic pole, the first material includes at least one selected from Ta, Pt, W, Ir, Mo, Cr, Tb, Mn and Ni, and the second material includes at least one selected from Cu, Ag, Au, Cr and Ru,

[0186] When the first magnetic pole side nonmagnetic layer includes the second material and the second magnetic pole side nonmagnetic layer includes the first material, when the element current has the first value, the element current has a second direction from the first magnetic pole toward the second magnetic pole.

[0187] (Technical Solution 9)

[0188] The magnetic recording device according to any one of technical solutions 1 to 8,

[0189] The coil current is an alternating current having a first frequency,

[0190] The third circuit detects the electrical signal obtained from the magnetic element.

[0191] The electrical signal has a second frequency that is twice the first frequency,

[0192] The resistance corresponds to the temporal average of the electrical signal.

[0193] (Technical Solution 10)

[0194] A magnetic recording device comprising:

[0195] A magnetic head, comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, wherein the magnetic element is arranged between the first magnetic pole and the second magnetic pole, the magnetic element comprises a first magnetic layer, a first magnetic pole side non-magnetic layer arranged between the first magnetic pole and the first magnetic layer, and a second magnetic pole side non-magnetic layer arranged between the first magnetic layer and the second magnetic pole, the first magnetic pole side non-magnetic layer comprises one of a first material and a second material, the second magnetic pole side non-magnetic layer comprises the other of the first material and the second material, the first material comprises at least one selected from Ta, Pt, W, Ir, Mo, Cr, Tb, Mn and Ni, and the second material comprises at least one selected from Cu, Ag, Au, Cr and Ru;

[0196] a first circuit capable of supplying a coil current to the coil; and

[0197] a second circuit capable of supplying an element current to the magnetic element,

[0198] The polarity of the coil current changes at the first moment,

[0199] The second circuit sets the device current to a first value before a second time, changes the device current to a second value different from the first value at the second time, and changes the device current to the first value at a third time after the second time.

[0200] (Technical Solution 11)

[0201] According to the magnetic recording device described in technical solution 10,

[0202] In a case where the first magnetic pole side non-magnetic layer includes the first material and the second magnetic pole side non-magnetic layer includes the second material, when the element current is the first value, the element current has a first direction from the second magnetic pole toward the first magnetic pole,

[0203] When the first magnetic pole side nonmagnetic layer includes the second material and the second magnetic pole side nonmagnetic layer includes the first material, when the element current has the first value, the element current has a second direction from the first magnetic pole toward the second magnetic pole.

[0204] (Technical Solution 12)

[0205] According to the magnetic recording device described in technical solution 10 or 11,

[0206] The second circuit changes the element current to a third value different from the first value and the second value at a fourth time before the second time, and changes the element current to the second value at a fifth time after the fourth time and before the second time.

[0207] (Technical Solution 13)

[0208] According to the magnetic recording device described in technical solution 12,

[0209] The first value is between the third value and the second value.

[0210] (Technical Solution 14)

[0211] According to the magnetic recording device described in technical solution 13,

[0212] An absolute value of a difference between the first value and the second value is greater than an absolute value of a difference between the first value and the third value.

[0213] (Technical Solution 15)

[0214] A magnetic recording device comprising:

[0215] A magnetic head, comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, wherein the magnetic element is arranged between the first magnetic pole and the second magnetic pole, and the magnetic element comprises a first magnetic layer, a second magnetic layer arranged between the first magnetic layer and the first magnetic pole, a first non-magnetic layer arranged between the first magnetic layer and the second magnetic layer, a first magnetic pole side non-magnetic layer arranged between the first magnetic pole and the second magnetic layer, and a second magnetic pole side non-magnetic layer arranged between the first magnetic layer and the second magnetic pole;

[0216] a first circuit capable of supplying a coil current to the coil; and

[0217] a second circuit capable of supplying an element current to the magnetic element,

[0218] The polarity of the coil current changes at the first moment,

[0219] The second circuit causes the element current to be the first value before the second moment, changes the element current to a second value different from the first value at the second moment, changes the element current to the first value at a third moment after the second moment, changes the element current to the third value different from the first value and also different from the second value at a fourth moment before the second moment, and changes the element current to the second value at a fifth moment after the fourth moment and before the second moment.

[0220] (Technical Solution 16)

[0221] A magnetic recording method is applied to a magnetic head, the magnetic head comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, the magnetic element is arranged between the first magnetic pole and the second magnetic pole, the magnetic element comprises a first magnetic layer, and the magnetic recording method comprises:

[0222] supplying a coil current to the coil of the magnetic head, supplying an element current to the magnetic element, detecting the resistance of the magnetic element,

[0223] The element current is controlled based on a result of detecting the resistance of the magnetic element.

[0224] (Technical Solution 17)

[0225] According to the magnetic recording method described in technical solution 16,

[0226] The polarity of the coil current changes at the first moment,

[0227] Before the second moment, the element current is set to the first value,

[0228] at the second time, changing the element current to a second value different from the first value;

[0229] at a third time after the second time, the element current is changed to the first value;

[0230] At least one of the second time, the third time, the first value, and the second value is controlled based on the result obtained by detecting the resistance of the magnetic element.

[0231] (Technical Solution 18)

[0232] According to the magnetic recording method described in technical solution 17,

[0233] at a fourth time before the second time, the device current is changed to a third value different from the first value and also different from the second value, and at a fifth time after the fourth time and before the second time, the device current is changed to the second value,

[0234] At least any one of the second time, the third time, the fourth time, the fifth time, the first value, the second value, and the third value is controlled based on the detected resistance.

[0235] (Technical Solution 19)

[0236] According to the magnetic recording method described in technical solution 18,

[0237] The first value is between the third value and the second value.

[0238] (Technical Solution 20)

[0239] According to the magnetic recording method described in technical solution 18 or 19,

[0240] The coil current is an alternating current having a first frequency,

[0241] The detecting of the resistance of the magnetic element comprises: detecting an electrical signal obtained from the magnetic element,

[0242] The electrical signal has a second frequency that is twice the first frequency,

[0243] The resistance corresponds to the temporal average of the electrical signal.

[0244] According to the embodiments, a magnetic recording device and a magnetic recording method capable of improving recording capability can be provided.

[0245] In the present specification, “perpendicular” and “parallel” do not only include strictly perpendicular and strictly parallel, but also include, for example, variations in the manufacturing process, and substantially perpendicular and substantially parallel are sufficient.

[0246] The embodiments of the present invention are described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific structure of each element of the magnetic head, magnetic pole, shield, magnetic element, magnetic layer, non-magnetic layer, wiring, circuit and control unit included in the magnetic recording device is included in the scope of the present invention as long as it can be appropriately selected by a person skilled in the art from the known range to implement the present invention in the same manner and obtain the same effect.

[0247] Furthermore, as long as the gist of the present invention is included, any solution obtained by combining two or more elements of each specific example within a technically feasible range is also included in the scope of the present invention.

[0248] In addition, as long as they include the purpose of the present invention, all magnetic recording devices and magnetic recording methods that can be implemented by those skilled in the art by appropriately making design changes based on the magnetic recording devices and magnetic recording methods described above as embodiments of the present invention also fall within the scope of the present invention.

[0249] Furthermore, it should be understood that within the scope of the present invention, those skilled in the art can conceive of various changes and modifications, and those changes and modifications also belong to the scope of the present invention.

[0250] Several embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. A magnetic recording device comprising: A magnetic head, comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, wherein the magnetic element is arranged between the first magnetic pole and the second magnetic pole, and the magnetic element comprises a first magnetic layer; a first circuit capable of supplying a coil current to the coil; a second circuit capable of supplying an element current to the magnetic element; a third circuit capable of detecting the resistance of the magnetic element; and a control unit capable of controlling the second circuit based on the resistance detected by the third circuit to control the element current, In a first operation performed by the magnetic recording device, the polarity of the coil current changes at a first moment. In the first operation, the second circuit causes the element current to be the first value before a fourth time before a second time, the second circuit causes the element current to change to a second value different from the first value at the second time, and causes the element current to change to the first value at a third time after the second time. In the first operation, the second circuit changes the element current to a third value different from the first value and also different from the second value at a fourth time before the second time, and changes the element current to the second value at a fifth time after the fourth time and before the second time. In the first action, the control unit can control the second circuit based on the resistance detected by the third circuit, thereby controlling at least any one of the second moment, the third moment, the fourth moment, the fifth moment, the first value, the second value, and the third value. The first value is between the third value and the second value, An absolute value of a difference between the first value and the second value is greater than an absolute value of a difference between the first value and the third value.

2. A magnetic recording method, applied to a magnetic head, the magnetic head comprising a first magnetic pole, a second magnetic pole, a magnetic element and a coil, the magnetic element being arranged between the first magnetic pole and the second magnetic pole, the magnetic element comprising a first magnetic layer, the magnetic recording method comprising: supplying a coil current to the coil of the magnetic head, supplying an element current to the magnetic element, detecting the resistance of the magnetic element, Based on the result of detecting the resistance of the magnetic element, the element current is controlled, in, The polarity of the coil current changes at the first moment, Before a fourth moment before the second moment, the element current is set to a first value, at the second time, changing the element current to a second value different from the first value; at a third time after the second time, the element current is changed to the first value; at a fourth time before the second time, the device current is changed to a third value different from the first value and also different from the second value, and at a fifth time after the fourth time and before the second time, the device current is changed to the second value, in, at least one of the second time, the third time, the fourth time, the fifth time, the first value, the second value, and the third value is controlled based on the detected resistance, The first value is between the third value and the second value, An absolute value of a difference between the first value and the second value is greater than an absolute value of a difference between the first value and the third value.

Images