阅读说明：本技术 磁头及磁记录再现装置
(Magnetic head and magnetic recording/reproducing apparatus
) 是由 成田直幸
前田知幸 于 2019-03-12 设计创作，主要内容包括：提供一种能够提高记录密度的磁头及磁记录再现装置。根据实施方式,磁头包括磁极、第1屏蔽件、第2屏蔽件、第1层叠体以及第2层叠体。磁极的至少一部分设置于第1屏蔽件与第2屏蔽件之间。第1层叠体设置于磁极与第1屏蔽件之间。第2层叠体设置于磁极与第2屏蔽件之间。第1层叠体包括：第1磁性层,包含选自Fe、Co以及Ni中的至少一个；第1导电层,设置于磁极与第1磁性层之间；以及第2导电层,设置于第1磁性层与第1屏蔽件之间。第2层叠体包括：第2磁性层,包含选自Fe、Co以及Ni中的至少一个；第3导电层,设置于磁极与第2磁性层之间；以及第4导电层,设置于第2磁性层与第2屏蔽件之间。(A magnetic head and a magnetic recording/reproducing apparatus capable of improving the recording density are provided. According to an embodiment, a magnetic head includes a magnetic pole, a1 st shield, a2 nd shield, a1 st stack, and a2 nd stack. At least a portion of the magnetic pole is disposed between the 1 st shield and the 2 nd shield. The 1 st stacked body is disposed between the magnetic pole and the 1 st shield. The 2 nd stacked body is disposed between the magnetic pole and the 2 nd shield. The 1 st laminate comprises: a1 st magnetic layer containing at least one selected from the group consisting of Fe, Co, and Ni; the 1 st conducting layer is arranged between the magnetic pole and the 1 st magnetic layer; and a2 nd conductive layer disposed between the 1 st magnetic layer and the 1 st shield. The 2 nd laminate includes: a2 nd magnetic layer containing at least one selected from Fe, Co, and Ni; the 3 rd conducting layer is arranged between the magnetic pole and the 2 nd magnetic layer; and a 4 th conductive layer disposed between the 2 nd magnetic layer and the 2 nd shield.)
1. A magnetic head includes:
a magnetic pole;
1 st shield;
a2 nd shield having at least a portion of the magnetic pole disposed between the 1 st shield and the 2 nd shield;
a1 st stacked body provided between the magnetic pole and the 1 st shield; and
a2 nd stacked body disposed between the magnetic pole and the 2 nd shield,
the 1 st stack includes:
a1 st magnetic layer containing at least one selected from the group consisting of Fe, Co, and Ni;
the 1 st conducting layer is arranged between the magnetic pole and the 1 st magnetic layer; and
a2 nd conductive layer disposed between the 1 st magnetic layer and the 1 st shield,
the 2 nd stack includes:
a2 nd magnetic layer containing at least one selected from Fe, Co, and Ni;
a 3 rd conductive layer disposed between the magnetic pole and the 2 nd magnetic layer; and
a 4 th conductive layer disposed between the 2 nd magnetic layer and the 2 nd shield.
2. The magnetic head as claimed in claim 1,
further provided with:
a1 st terminal electrically connected to the 1 st shield; and
and a2 nd terminal electrically connected to the 2 nd shield.
3. The magnetic head as claimed in claim 1,
the 1 st conductive layer contains at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh and Pd,
the 2 nd conductive layer contains at least one selected from Cu, Ag, Al and Au,
the 3 rd conductive layer contains at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh and Pd,
the 4 th conductive layer includes at least one selected from Cu, Ag, Al, and Au.
4. The magnetic head as claimed in claim 1,
the 1 st conductive layer includes at least one selected from Cu, Ag, Al and Au,
the 2 nd conductive layer contains at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh and Pd,
the 3 rd conductive layer includes at least one selected from Cu, Ag, Al and Au,
the 4 th conductive layer includes at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd.
5. The magnetic head as claimed in claim 1,
a current can be passed from the 2 nd conductive layer to the 1 st conductive layer and a current can be passed from the 3 rd conductive layer to the 4 th conductive layer.
6. The magnetic head as claimed in claim 1,
a current can be passed from the 4 th conductive layer to the 3 rd conductive layer and a current can be passed from the 2 nd conductive layer to the 1 st conductive layer.
7. The magnetic head as claimed in claim 1,
a1 st resistance between the magnetic pole and the 1 st shield when a1 st current flows between the magnetic pole and the 1 st shield is different from a2 nd resistance between the magnetic pole and the 1 st shield when a2 nd current flows between the magnetic pole and the 1 st shield, and a direction of the 2 nd current is opposite to a direction of the 1 st current.
8. The magnetic head as claimed in claim 1,
a 3 rd resistance between the magnetic pole and the 2 nd shield when a2 nd current flows between the magnetic pole and the 2 nd shield is different from a 4 th resistance between the magnetic pole and the 2 nd shield when a1 st current flows between the magnetic pole and the 2 nd shield, and a direction of the 2 nd current is opposite to a direction of the 1 st current.
9. The magnetic head as claimed in claim 1,
when a1 st current from the 1 st shield toward the 2 nd shield is caused to flow in the 1 st stack and the 2 nd stack and the magnitude of the 1 st current is increased, the resistance between the 1 st shield and the 2 nd shield increases nonlinearly,
when a2 nd current from the 2 nd shield toward the 1 st shield is caused to flow in the 1 st stack and the 2 nd stack and the magnitude of the 2 nd current is increased, the resistance increases nonlinearly.
10. A magnetic recording/reproducing apparatus includes:
the magnetic head of claim 2;
a magnetic recording medium through which information is recorded; and
the 1 st circuit is used for carrying out the following steps,
the 1 st circuit supplies a current in a direction from the 1 st terminal to the 2 nd terminal when the magnetic head faces the 1 st region of the magnetic recording medium,
the 1 st circuit supplies a current in a direction from the 2 nd terminal to the 1 st terminal when the magnetic head faces the 2 nd region of the magnetic recording medium.
Technical Field
Embodiments of the present invention relate to a magnetic head and a magnetic recording and reproducing apparatus.
Background
Information is recorded on a magnetic storage medium such as an hdd (hard Disk drive) using a magnetic head. In a magnetic head and a magnetic recording and reproducing apparatus, it is desired to increase the recording density.
Disclosure of Invention
Embodiments of the invention provide a magnetic head and a magnetic recording and reproducing apparatus capable of improving recording density.
According to an embodiment of the present invention, a magnetic head includes a magnetic pole, a1 st shield, a2 nd shield, a1 st stack, and a2 nd stack. Disposing at least a portion of the magnetic pole between the 1 st shield and the 2 nd shield. The 1 st stacked body is disposed between the magnetic pole and the 1 st shield. The 2 nd stacked body is disposed between the magnetic pole and the 2 nd shield. The 1 st stack includes: a1 st magnetic layer containing at least one selected from the group consisting of Fe, Co, and Ni; the 1 st conducting layer is arranged between the magnetic pole and the 1 st magnetic layer; and a2 nd conductive layer disposed between the 1 st magnetic layer and the 1 st shield. The 2 nd stack includes: a2 nd magnetic layer containing at least one selected from Fe, Co, and Ni; a 3 rd conductive layer disposed between the magnetic pole and the 2 nd magnetic layer; and a 4 th conductive layer disposed between the 2 nd magnetic layer and the 2 nd shield.
According to the magnetic head having the above configuration, a magnetic head and a magnetic recording and reproducing apparatus capable of improving recording density can be provided.
Drawings
Fig. 1(a) and 1(b) are schematic views illustrating a magnetic head according to embodiment 1.
Fig. 2 is a schematic view illustrating the magnetic head according to embodiment 1.
Fig. 3(a) and 3(b) are schematic diagrams illustrating the operation of the magnetic head according to embodiment 1.
Fig. 4 is a diagram illustrating characteristics of a magnetic head.
Fig. 5(a) and 5(b) are diagrams illustrating characteristics of the magnetic head.
Fig. 6 is a schematic diagram illustrating an operation of the magnetic head according to the embodiment.
Fig. 7 is a schematic diagram illustrating a magnetic recording and reproducing apparatus according to an embodiment.
Fig. 8 is a schematic perspective view illustrating a part of the magnetic recording and reproducing device according to the embodiment.
Fig. 9 is a schematic perspective view illustrating a magnetic recording and reproducing apparatus according to an embodiment.
Fig. 10(a) and 10(b) are schematic perspective views illustrating a part of the magnetic recording and reproducing device according to the embodiment.
Description of the reference symbols
11. 12: 1 st and 2 nd magnetic layers;
11M, 12M: magnetizing;
20D: a1 st circuit;
21-24: the 1 st to 4 th conductive layers;
21sp, 22 sp: a spin torque;
30: a magnetic pole;
30D: a2 nd circuit;
30F: the 1 st surface;
30M: magnetizing;
30 c: a coil;
30 i: an insulating section;
30M: magnetizing;
31-34: 1 st to 4 th shields;
31M: magnetizing;
80: a magnetic recording medium;
80 c: a center;
85: a direction of media movement;
110: a magnetic head;
150: a magnetic recording and reproducing device;
154: a suspension;
155: an arm;
156: a voice coil motor;
157: a bearing portion;
158: a head gimbal assembly;
159: a head slider;
159A: an air inflow side;
159B: an air outflow side;
160: a head stack assembly;
161: a support frame;
162: a coil;
180: a recording medium disk;
180M: a spindle motor;
181: a recording medium;
190: a signal processing unit;
AR, AR 1: an arrow;
D1-D3: the 1 st direction;
H1-H3: a magnetic field;
hg 1: a gap magnetic field;
i1, I2: 1 st and 2 nd currents;
IT: current flow;
IT 1-IT 4: a value;
HS: magnetic field strength;
ic: current flow;
je: a stream of electrons;
m1, M2: 1 st and 2 nd models;
OP1, OP 2: 1, 2 nd actions;
RT: a resistance;
SB1, SB 2: 1 st and 2 nd laminated bodies;
t1, T2: 1 st and 2 nd terminals;
w1, W2: 1 st and 2 nd wirings;
pY: a location;
pa: an inner peripheral area;
pb: a peripheral region;
pc: a middle region;
t11, t12, t21, t22, t23, t 24: and (4) thickness.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual drawings, and the relationship between the thickness and the width of each portion, the ratio of the sizes of the portions, and the like are not necessarily the same as those in practice. Even when the same portions are indicated, the sizes and ratios of the portions may be indicated differently according to the drawings.
In the present specification and the drawings, the same elements as those described in the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.
(embodiment 1)
Fig. 1(a), 1(b), and 2 are schematic views illustrating a magnetic head according to embodiment 1.
FIG. 1(a) is a sectional view taken along line B1-B2 of FIG. 1 (B). Fig. 1(b) is a plan view as seen from an arrow AR1 in fig. 1 (a). FIG. 2 is a cross-sectional view taken along line A1-A2 of FIG. 1 (a).
As shown in fig. 1(b), a magnetic head 110 according to the embodiment includes a magnetic pole 30, a1 st shield 31, a2 nd shield 32, a1 st stacked body SB1, and a2 nd stacked body SB 2. At least a portion of the magnetic pole 30 is disposed between the 1 st shield 31 and the 2 nd shield 32. The 1 st stacked body SB1 is provided between the magnetic pole 30 and the 1 st shield 31. The 2 nd laminated body SB2 is disposed between the magnetic pole 30 and the 2 nd shield 32.
As shown in fig. 1(a), a coil 30c, a 3 rd shield 33, and a 4 th shield 34 are also provided.
The direction from the magnetic pole 30 to the 3 rd shield 33 is along the 1 st direction D1 (see fig. 1(a) and 1 (b)). The 1 st direction D1 is defined as the X-axis direction. One direction perpendicular to the X-axis direction is set as the Z-axis direction. The direction perpendicular to the X-axis direction and the Z-axis direction is referred to as the Y-axis direction.
The magnetic pole 30 is, for example, a main magnetic pole. The pole 30 includes a1 st face 30F. The 1 st face 30F is opposed to the magnetic recording medium 80. The 1 st face 30F corresponds to, for example, the medium opposing face. The 1 st Surface 30F corresponds to, for example, an ABS (Air Bearing Surface).
A recording circuit (2 nd circuit 30D) is electrically connected to the coil 30 c. A recording current is supplied from the recording circuit to the coil 30 c. A magnetic field (recording magnetic field) corresponding to the recording current is generated from the magnetic pole 30. A recording magnetic field is applied to the magnetic recording medium 80, recording information to the magnetic recording medium 80. In this manner, the recording circuit (2 nd circuit 30D) can supply a current (recording current) corresponding to the recorded information to the coil 30 c.
For example, the direction perpendicular to the 1 st surface 30F is the Z-axis direction. The Z-axis direction is, for example, a height direction. The X-axis direction is, for example, the track direction. The Y-axis direction is, for example, a cross-track direction. The 1 st direction D1(X axis direction) is along the relative moving direction between the magnetic recording medium 80 and the magnetic pole 30 where the magnetic pole 30 is opposed. The angle between the 1 st direction D1 and the direction of relative movement between the magnetic recording medium 80 and the magnetic pole 30, which the magnetic pole 30 faces, is ± 25 degrees or less. The angle may be ± 20 degrees or less. The absolute value of the angle between the 1 st direction D1 and the along-track direction is smaller than the absolute value of the angle between the 1 st direction D1 and the cross-track direction.
The 3 rd shield 33 corresponds to, for example, a "trailing shield: trailing shield ". The 4 th shield 34 corresponds to, for example, "leading shield: leading shield ". The 3 rd shield 33 is, for example, an auxiliary pole. The 3 rd shield 33 can form a magnetic core together with the magnetic pole 30. The 4 th shield 34 is, for example, an auxiliary pole. The 4 th shield 34 may also form a magnetic core with the pole 30.
The direction from the magnetic pole 30 toward the 3 rd shield 33 (the 1 st direction D1) intersects the direction from the 1 st shield 31 toward the 2 nd shield 32 (the Y-axis direction in this example).
The 1 st shield 31 corresponds to, for example, the 1 st side shield. The 2 nd shield 32 corresponds to, for example, a2 nd side shield.
The 1 st stacked body SB1 includes a1 st magnetic layer 11, a1 st conductive layer 21, and a2 nd conductive layer 22. The 1 st magnetic layer 11 contains at least one selected from Fe, Co, and Ni. The 1 st magnetic layer 11 is, for example, a FeCo layer or a FeNi layer. The 1 st magnetic layer 11 is, for example, ferromagnetic. The 1 st magnetic layer 11 contains, for example, a ferromagnetic metal.
The 1 st conductive layer 21 is disposed between the magnetic pole 30 and the 1 st magnetic layer 11. The 2 nd conductive layer 22 is disposed between the 1 st magnetic layer 11 and the 1 st shield 31. The 1 st conductive layer 21 and the 2 nd conductive layer 22 are, for example, nonmagnetic. The 1 st conductive layer 21 and the 2 nd conductive layer 22 contain, for example, a nonmagnetic metal. For example, the material of the 1 st conductive layer 21 is different from the material of the 2 nd conductive layer 22.
In one example, the 1 st conductive layer 21 interfaces with the magnetic pole 30 and the 1 st magnetic layer 11. In one example, the 2 nd conductive layer 22 interfaces with the 1 st magnetic layer 11 and the 1 st shield 31.
The 2 nd laminated body SB2 includes a2 nd magnetic layer 12, a 3 rd conductive layer 23, and a 4 th conductive layer 24. The 2 nd magnetic layer 12 contains at least one selected from Fe, Co, and Ni. The 2 nd magnetic layer 12 is, for example, a FeCo layer or a FeNi layer. The 2 nd magnetic layer 12 is, for example, ferromagnetic. The 2 nd magnetic layer 12 contains, for example, a ferromagnetic metal.
The 3 rd conductive layer 23 is disposed between the magnetic pole 30 and the 2 nd magnetic layer 12. The 4 th conductive layer 24 is disposed between the 2 nd magnetic layer 12 and the 2 nd shield 32. The 3 rd conductive layer 23 and the 4 th conductive layer 24 are, for example, nonmagnetic. The 3 rd conductive layer 23 and the 4 th conductive layer 24 contain, for example, a nonmagnetic metal. For example, the material of the 3 rd conductive layer 23 is different from the material of the 4 th conductive layer 24.
In one example, conductive layer 3 23 interfaces with magnetic pole 30 and magnetic layer 2 12. In one example, the 4 th conductive layer 24 interfaces with the 2 nd magnetic layer 12 and the 2 nd shield 32.
The magnetic pole 30 is electrically connected to the 1 st shield 31 via the 1 st stacked body SB 1. The magnetic pole 30 is electrically connected to the 2 nd shield 32 via the 2 nd stacked body SB 2.
In this example, the insulation portions 30i electrically insulate between the 1 st shield 31 and the 3 rd shield 33, between the 2 nd shield 32 and the 3 rd shield 33, between the 1 st shield 31 and the 4 th shield 34, and between the 2 nd shield 32 and the 4 th shield 34. In the embodiment, the 3 rd shield 33 may be electrically connected to one of the 1 st shield 31 and the 2 nd shield 32. The 4 th shield 34 may be electrically connected to the other of the 1 st shield 31 and the 2 nd shield 32.
For example, the thickness of the 1 st magnetic layer 11 along the direction from the magnetic pole 30 to the 1 st shield 31 (for example, the 2 nd direction D2) is set to be the thickness t 11. The thickness t11 is, for example, 4nm or more and 20nm or less.
The thickness of the 1 st conductive layer 21 in the direction from the magnetic pole 30 to the 1 st shield 31 (the 2 nd direction D2) is set to a thickness t 21. The thickness of the 2 nd conductive layer 22 along the 2 nd direction D2 is set to a thickness t 22. The thickness t21 and the thickness t22 are 0.3nm to 15nm, respectively.
For example, the thickness of the 2 nd magnetic layer 12 along the direction from the magnetic pole 30 to the 2 nd shield 32 is set to the thickness t 12. The thickness t12 is, for example, 4nm or more and 20nm or less.
The thickness of the 3 rd conductive layer 23 along the direction from the magnetic pole 30 to the 2 nd shield 32 (the 3 rd direction D3) is set to a thickness t 23. The thickness of the 4 th conductive layer 24 along the 3 rd direction D3 is set to a thickness t 24. The thickness t23 and the thickness t24 are, for example, 0.3nm or more and 15nm or less, respectively.
As will be described later, with such a thickness, for example, the magnetization of the 1 st magnetic layer 11 and the magnetization of the 2 nd magnetic layer 12 are likely to have desired directions.
As shown in fig. 1(b) and 2, a1 st terminal T1 and a2 nd terminal T2 are provided. The 1 st terminal T1 is electrically connected to the 1 st shield 31. The 2 nd terminal T2 is electrically connected to the 2 nd shield 32.
For example, the 1 st wire W1 and the 2 nd wire W2 may be provided. The 1 st wire W1 is electrically connected to the 1 st terminal T1. The 2 nd wire W2 is electrically connected to the 2 nd terminal T2.
For example, the 1 st wire W1 and the 2 nd wire W2 are electrically connected to the 1 st circuit 20D. The 1 st circuit 20D can supply a current (the 1 st current I1 or the 2 nd current I2) to the 1 st stack SB1 and the 2 nd stack SB 2.
The magnetic head 110 may also perform action 1 OP 1. In the 1 st operation OP1, a current (the 1 st current I1) in a direction from the 1 st terminal T1 to the 2 nd terminal T2 flows through a path including the 1 st stacked body SB1, the magnetic pole 30, and the 2 nd stacked body SB 2. In the 1 st action OP1, the potential of the 1 st terminal T1 is higher than the potential of the 2 nd terminal T2.
The head 110 may also perform action 2 OP 2. In the 2 nd operation OP2, a current (the 2 nd current I2) in a direction from the 2 nd terminal T2 to the 1 st terminal T1 flows through a path including the 2 nd stacked body SB2, the magnetic pole 30, and the 1 st stacked body SB 1. In the 2 nd action OP2, the potential of the 2 nd terminal T2 is higher than the potential of the 1 st terminal T1.
When a current flows through such a stacked body (at least any one of the 1 st stacked body SB1 and the 2 nd stacked body SB 2), the direction of magnetization of the magnetic layer (at least any one of the 1 st magnetic layer 11 and the 2 nd magnetic layer 12) included in the stacked body can be controlled. For example, the magnetization of the magnetic layer is made to have a component opposite to the direction of the magnetic field emitted from the magnetic pole 30. This makes it possible to appropriately control the distribution of the direction of the magnetic field emitted from the magnetic pole 30.
The following describes an operation in an example. In this example, the 1 st conductive layer 21 contains Ir, and the 2 nd conductive layer 22 contains Cu. The 3 rd conductive layer 23 contains Ir, and the 4 th conductive layer 24 contains Cu.
Fig. 3(a) and 3(b) are schematic diagrams illustrating the operation of the magnetic head according to embodiment 1.
Fig. 3(a) corresponds to action 1 OP 1. Fig. 3(b) corresponds to action 2 OP 2.
As shown in fig. 3(a), in the 1 st action OP1, the 1 st current I1 flows through the 1 st shield 31, the 2 nd conductive layer 22, the 1 st magnetic layer 11, the 1 st conductive layer 21, the magnetic pole 30, the 3 rd conductive layer 23, the 2 nd magnetic layer 12, the 4 th conductive layer 24, and the 2 nd shield 32 in this order.
A recording current flows in the coil 30c, thereby generating a magnetic field from the magnetic pole 30. A part of the magnetic field emitted from the magnetic pole 30 (magnetic field H1) is directed toward the magnetic recording medium 80. On the other hand, the other part of the magnetic field emitted from the magnetic pole 30 has a component toward the 1 st shield 31 or a component toward the 2 nd shield 32.
When the 1 st current I1 flows in the 1 st stack SB1, the magnetization 11M of the 1 st magnetic layer 11 has a component opposite to the other part of the magnetic field (magnetic field H2) emitted from the magnetic pole 30. This is based, for example, on the action of spin transfer torque (spin torque). This makes it difficult for the magnetic field H2 to pass through the 1 st magnetic layer 11. As a result, the magnetic field H2 is easily directed toward the magnetic recording medium 80. This enables the intensity of the recording magnetic field to be changed rapidly at the end in the cross-track direction (the end on the 1 st shield 31 side). The strength of the magnetic field at that end can be enhanced.
On the other hand, the other part of the magnetic field emitted from the magnetic pole 30 (magnetic field H3) has a component toward the 2 nd shield 32. When the 1 st current I1 flows through the 2 nd stack SB2, the magnetization 12M of the 2 nd magnetic layer 12 has a component in the same direction as the magnetic field H3. Thereby, the magnetic field H3 passes through the 2 nd magnetic layer 12. Thus, the strength of the recording magnetic field does not change rapidly at the end in the cross-track direction (the end on the 2 nd shield 32 side).
In the embodiment, the distribution of the magnetic field in the cross-track direction can be made asymmetric. For example, when the distribution of the magnetic field is asymmetric, the intensity at one end can be enhanced as compared with the case where the distribution of the magnetic field is symmetric.
For example, tile Recording (shift Recording) is sometimes performed. In the shingle recording, a2 nd track is overlapped on a part of a1 st track where recording is performed, and the 2 nd track is recorded. By enhancing the magnetic field at one end of the 2 nd track, the tile recording can be performed more favorably.
In an embodiment, for example, the distribution of the recording magnetic field across the track direction can be controlled. Thus, for example, even if the interval in the cross-track direction of the plurality of tracks is narrowed, good recording and reproducing characteristics can be obtained.
According to the embodiment, a magnetic head and a magnetic recording and reproducing apparatus capable of improving recording density can be provided.
As shown in fig. 3(b), in the 2 nd action OP2, the 2 nd current I2 flows through the 2 nd shield 32, the 4 th conductive layer 24, the 2 nd magnetic layer 12, the 3 rd conductive layer 23, the magnetic pole 30, the 1 st conductive layer 21, the 1 st magnetic layer 11, the 2 nd conductive layer 22, and the 1 st shield 31 in this order.
In this case, the recording current also flows in the coil 30c, thereby generating a magnetic field from the magnetic pole 30. A part of the magnetic field emitted from the magnetic pole 30 (magnetic field H1) is directed toward the magnetic recording medium 80. The other part of the magnetic field emitted from the magnetic pole 30 has a component toward the 1 st shield 31 or a component toward the 2 nd shield 32.
When the 2 nd current I2 flows in the 2 nd stack SB2, the magnetization 12M of the 2 nd magnetic layer 12 has a component opposite to the other part of the magnetic field (magnetic field H3) emitted from the magnetic pole 30. This is based, for example, on the effect of spin transfer torque. This makes it difficult for the magnetic field H3 to pass through the 2 nd magnetic layer 12. As a result, the magnetic field H3 is easily directed toward the magnetic recording medium 80. This enables the intensity of the recording magnetic field to be changed rapidly at the end in the cross-track direction (the end on the 2 nd shield 32 side). The strength of the magnetic field at that end can be enhanced.
On the other hand, the magnetic field H2 emitted from the magnetic pole 30 has a component toward the 1 st shield 31. When the 2 nd current I2 was applied to the 1 st stacked body SB1, the magnetization 11M of the 1 st magnetic layer 11 had a component in the same direction as the magnetic field H2. Thereby, the magnetic field H2 passes through the 1 st magnetic layer 11. Thus, the strength of the recording magnetic field does not change rapidly at the end in the cross-track direction (the end on the 1 st shield 31 side).
In the 2 nd action OP2, the distribution of the magnetic field in the cross-track direction can also be made asymmetric. For example, when the distribution of the magnetic field is asymmetric, the intensity at one end can be enhanced as compared with the case where the distribution of the magnetic field is symmetric.
In tile recording, the positions of the end portions that are recorded so as to overlap may vary in the inner peripheral region and the outer peripheral region. In this case, one of the 1 st operation OP1 and the 2 nd operation OP2 may be performed in the inner peripheral region. In the outer peripheral region, one of the 1 st operation OP1 and the 2 nd operation OP2 may be performed. The tile recording can be performed more favorably.
It can be considered that in the 1 st magnetic layer 11 and the 2 nd magnetic layer 12, the directions of magnetization (magnetization 11M and magnetization 12M) depend on the direction of current and the characteristics of the material of the conductive layer.
In the 1 st configuration (one example), the 1 st conductive layer 21 contains at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd. At this time, the 2 nd conductive layer 22 includes at least one selected from Cu, Ag, Al, and Au. At this time, the 3 rd conductive layer 23 includes at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd. At this time, the 4 th conductive layer 24 includes at least one selected from Cu, Ag, Al, and Au.
In the 1 st configuration, a current may be passed from the 2 nd conductive layer 22 to the 1 st conductive layer 21 and a current may be passed from the 3 rd conductive layer 23 to the 4 th conductive layer 24. For example, when the 1 st current I1 is supplied in a direction from the 1 st terminal T1 to the 2 nd terminal T2 (1 st action OP1), the magnetization 11M of the 1 st magnetic layer 11 has a direction opposite to the magnetic field emitted from the magnetic pole 30. The magnetization 12M of the 2 nd magnetic layer 12 is not inverted.
In the 1 st configuration, when the 2 nd current I2 is supplied in the direction from the 2 nd terminal T2 to the 1 st terminal T1 (the 2 nd operation OP2), the magnetization 12M of the 2 nd magnetic layer 12 has a direction opposite to the magnetic field emitted from the magnetic pole 30. The magnetization 11M of the 1 st magnetic layer 11 is not inverted.
In the configuration 2 (another example), in one example, the 1 st conductive layer 21 contains at least one selected from Cu, Ag, Al, and Au. At this time, the 2 nd conductive layer 22 includes at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd. At this time, the 3 rd conductive layer 23 includes at least one selected from Cu, Ag, Al, and Au. The 4 th conductive layer 24 contains at least one selected from Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd.
In the 2 nd configuration, a current may be passed from the 4 th conductive layer 24 to the 3 rd conductive layer 23 and a current may be passed from the 1 st conductive layer 21 to the 2 nd conductive layer 22. For example, when the 2 nd current I2 is supplied in a direction from the 2 nd terminal T2 to the 1 st terminal T1 (2 nd action OP2), the magnetization 11M of the 1 st magnetic layer 11 has a direction opposite to the magnetic field emitted from the magnetic pole 30. The magnetization 12M of the 2 nd magnetic layer 12 is not inverted.
In the 2 nd configuration, when the 1 st current I1 is supplied in the direction from the 1 st terminal T1 to the 2 nd terminal T2 (1 st operation OP1), the magnetization 12M of the 2 nd magnetic layer 12 has a direction opposite to the magnetic field emitted from the magnetic pole 30. The magnetization 11M of the 1 st magnetic layer 11 is not inverted.
In the embodiment, the resistance between the magnetic pole 30 and the 1 st shield 31 may also vary according to the direction of the magnetization 11M of the 1 st magnetic layer 11. For example, the resistance between the magnetic pole 30 and the 1 st shield 31 when the 1 st current I1 flows between the magnetic pole 30 and the 1 st shield 31 is set to the 1 st resistance. The resistance between the magnetic pole 30 and the 1 st shield 31 when the 2 nd current I2 flows between the magnetic pole 30 and the 1 st shield 31 is set to the 2 nd resistance. The 1 st resistance is different from the 2 nd resistance. The direction of the 2 nd current I2 is opposite to the direction of the 1 st current I1.
For example, the resistance between the magnetic pole 30 and the 2 nd shield 32 when the 2 nd current I2 flows between the magnetic pole 30 and the 2 nd shield 32 is set to the 3 rd resistance. The resistance between the magnetic pole 30 and the 2 nd shield 32 when the 1 st current I1 flows between the magnetic pole 30 and the 2 nd shield 32 is set to the 4 th resistance. The 3 rd resistance is different from the 4 th resistance. In this case, the direction of the 2 nd current I2 is also opposite to the direction of the 1 st current I1.
Fig. 4 is a diagram illustrating characteristics of a magnetic head.
Fig. 4 illustrates a change in resistance in the magnetic head 110. The horizontal axis is a current IT flowing between the 1 st terminal T1 and the 2 nd terminal T2. The vertical axis is the resistance RT between the 1 st terminal T1 and the 2 nd terminal T2.
As shown in fig. 4, when the absolute value of the current IT flowing between the 1 st terminal T1 and the 2 nd terminal T2 becomes large, the resistance RT between the 1 st terminal T1 and the 2 nd terminal T2 increases non-linearly. When the 1 st current from the 1 st shield 31 to the 2 nd shield 32 is caused to flow through the 1 st stacked body SB1 and the 2 nd stacked body SB2 and the magnitude of the 1 st current is increased, the resistance (which may be the resistance RT) between the 1 st shield 31 and the 2 nd shield 32 increases nonlinearly. When the 2 nd current from the 2 nd shield 32 to the 1 st shield 31 is caused to flow to the 1 st stacked body SB1 and the 2 nd stacked body SB2 and the magnitude of the 2 nd current is increased, the resistance (which may be the resistance RT) increases nonlinearly.
For example, when the absolute value of the current IT is small (the current IT is 0 to the value IT1 or 0 to the value IT3), the resistance RT rises in a curve. This is considered to be because of a temperature rise caused by the current IT.
When the absolute value of the current IT becomes larger, the resistance RT rises sharply (the current IT has a value IT1 to a value IT2 or a value IT3 to a value IT 4). This is considered to be because one of the magnetization 11M of the 1 st magnetic layer 11 and the magnetization 12M of the 2 nd magnetic layer 12 is inverted. For example, when the current IT is positive, one of the magnetization 11M and the magnetization 12M is inverted. For example, when the current IT is negative, the other of the magnetization 11M and the magnetization 12M is inverted.
The magnetization-inverted magnetic layer depends on the material of the conductive layer included in the stacked body and the direction of current flow.
In fig. 4, the resistance RT is substantially symmetrical with respect to the positive and negative of the current IT. In the embodiment, the asymmetry may be provided. The symmetry depends for example on the material etc.
The difference in resistance described above is based on the magnetoresistance effect, for example.
In a material selected from at least one of Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd, the spin diffusion length is small. By using such a material, the magnetization reversal efficiency (for example, the magnetization reversal rate) of the magnetic layer (the 1 st magnetic layer 11 or the 2 nd magnetic layer 12) can be increased.
When Ta is used for the conductive layer, for example, it is considered that spin transfer torque acting on the magnetic layer at the interface between the magnetic layer and the conductive layer can be suppressed.
Fig. 5(a) and 5(b) are diagrams illustrating characteristics of the magnetic head.
These figures show the simulation results of the off-track plot of the magnetic field of the head. The horizontal axis represents the position py (nm) in the Y-axis direction. The vertical axis of these figures is the magnetic field strength hs (oe) applied from the magnetic pole 30 to the magnetic recording medium 80. The characteristics of the 1 st model M1 and the 2 nd model M2 with respect to the simulation model are shown in these figures. The 1 st model M1 has the structure of the magnetic head 110 described above, and performs the 1 st action OP1 (supplying the 1 st current I1) or the 2 nd action OP2 (supplying the 2 nd current I2). On the other hand, in the 2 nd model M2, the 1 st stack SB1 and the 2 nd stack SB2 were not provided.
Fig. 5(a) illustrates characteristics of the 1 st model M1 in the 1 st action OP 1. Fig. 5(b) illustrates characteristics of the 1 st model M1 in the 2 nd action OP 2. The characteristics of the 2 nd model M2 are illustrated in both of these figures.
As shown in fig. 5(a) and 5(b), in the 2 nd model M2, a characteristic symmetrical about the position pY of 0nm can be obtained.
As shown in fig. 5(a), in the 1 st action OP1 of the 1 st model M1, the change in the recording magnetic field HS in the region where the position pY is positive is steeper than the change in the recording magnetic field HS in the region where the position pY is negative. This corresponds to a case where the recording magnetic field HS changes abruptly at one end (end on the 1 st shield 31 side) in the cross-track direction.
As shown in fig. 5(b), in action 2 OP2 of the 1 st model M1, the change in the recording magnetic field HS in the region where the position pY is negative is steeper than the change in the recording magnetic field HS in the region where the position pY is positive. This corresponds to a case where the recording magnetic field HS changes abruptly at the other end (end on the 2 nd shield 32 side) in the cross-track direction.
In this way, the distribution of the magnetic field in the cross-track direction can be made asymmetric. For example, the tile recording can be performed more favorably. For example, even if the interval in the cross-track direction of a plurality of tracks is narrowed, good recording and reproducing characteristics can be obtained. According to the embodiment, the recording density can be improved.
Hereinafter, an example of the operation of the magnetic head 110 according to the embodiment will be described. The 1 st layered product SB1 will be described below. The following description can be applied to the 2 nd stacked body SB2 by replacing the 1 st stacked body SB1 with the 2 nd stacked body SB2 and replacing the 1 st shield 31 with the 2 nd shield 32.
Fig. 6 is a schematic diagram illustrating an operation of the magnetic head according to the embodiment.
As shown in fig. 6, a1 st stacked body SB1 is provided between the magnetic pole 30 and the 1 st shield 31. In the 1 st stacked body SB1, the 1 st magnetic layer 11, the 1 st conductive layer 21, and the 2 nd conductive layer 22 are provided.
A recording current is supplied from the 2 nd circuit 30D (see fig. 1 a) to the coil 30c of the magnetic pole 30. Thereby, the gap magnetic field Hg1 is generated from the magnetic pole 30. A gap magnetic field Hg1 was applied to the 1 st stack SB 1.
For example, the magnetization 30M of the pole 30 and the magnetization 31M of the 1 st shield 31 are substantially parallel to the gap magnetic field Hg 1. The magnetization 11M of the 1 st magnetic layer 11 is substantially parallel to the gap magnetic field Hg 1.
At this time, the current Ic (corresponding to the 1 st current I1) is supplied from the 1 st circuit 20D to the 1 st stacked body SB 1. In this example, the current Ic is supplied to the 1 st stacked body SB1 via the 1 st shield 31 and the magnetic pole 30. The current Ic flows from, for example, the 2 nd conductive layer 22 to the 1 st conductive layer 21. At this time, the electron current Je flows. The electron current Je flows from the 1 st conductive layer 21 to the 2 nd conductive layer 22.
By the electron current Je, spin torque 21sp is generated at the interface between the 1 st conductive layer 21 and the 1 st magnetic layer 11. The spin torque 21sp is of a transmission type. On the other hand, a spin torque 22sp is generated at the interface between the 1 st magnetic layer 11 and the 2 nd conductive layer 22 by the electron current Je. Spin torque 22sp is a reflection type. By the above-described spin torque, the magnetization 11M of the 1 st magnetic layer 11 is inverted. The reversed magnetization 11M has a component opposite to the gap magnetic field Hg 1.
The current Ic may flow from the 1 st conductive layer 21 toward the 2 nd conductive layer 22, for example. At this time, the direction of spin torque 21sp and the direction of spin torque 22sp shown in fig. 6 are reversed. Spin torque 21sp is a reflection type, and spin torque 22sp is a transmission type.
In an embodiment, the above-described 1 st action OP1 or 2 nd action OP2 is performed. An example of the above-described operation will be described below.
Fig. 7 is a schematic diagram illustrating a magnetic recording and reproducing apparatus according to an embodiment.
As shown in fig. 7, the planar shape of the magnetic recording medium 80 is, for example, substantially circular. On the other hand, a movable arm 155 is provided at the tip end portion. The magnetic pole 30 (magnetic head 110) is provided at the tip end portion of the arm 155. The arm 155 rotates about a predetermined fulcrum, and the magnetic pole 30 moves relative to the magnetic recording medium 80.
The magnetic recording medium 80 is, for example, a disk shape having a center 80 c. The magnetic recording medium 80 includes an inner peripheral region pa, an outer peripheral region pb, and a middle region pc. An inner peripheral region pa is provided between the outer peripheral region pb and the center 80 c. A middle region pc is provided between the outer peripheral region pb and the inner peripheral region pa. The magnetic recording medium 80 rotates about the center 80 c. The medium moving direction 85 corresponds to the circumferential direction.
For example, one of the inner peripheral region pa and the outer peripheral region pb is defined as the 1 st region. The other of the inner peripheral region pa and the outer peripheral region pb is defined as a2 nd region.
For example, when the magnetic head 110 (magnetic pole 30) faces the 1 st region of the magnetic recording medium 80, the 1 st circuit 20D supplies a current (the 1 st current I1) in a direction from the 1 st terminal T1 to the 2 nd terminal T2 (see fig. 1 (b)).
For example, when the magnetic head 110 (magnetic pole 30) faces the 2 nd region of the magnetic recording medium 80, the 1 st circuit 20D supplies a current (the 2 nd current I2) in a direction from the 2 nd terminal T2 to the 1 st terminal T1.
The magnetic recording medium 80 rotates about a portion (center 80c) of the magnetic recording medium 80. The 1 st region is one of the inner peripheral region pa and the outer peripheral region pb during the rotation. The 2 nd region is the other of the inner peripheral region pa and the outer peripheral region pb during the above-described rotation.
The magnetic head 110 performs tile recording on the magnetic recording medium 80, for example. In the embodiment, good tile recording can be performed. A magnetic head and a magnetic recording/reproducing apparatus capable of improving the recording density can be provided.
(embodiment 2)
Embodiment 2 relates to a magnetic recording and reproducing apparatus. The magnetic recording and reproducing apparatus includes, for example, the magnetic head 110 (and a modified magnetic head thereof) described in relation to embodiment 1. The magnetic recording and reproducing device further includes a magnetic recording medium 80, and a1 st circuit 20D capable of supplying a current to the 1 st stacked body SB1 and the 2 nd stacked body SB 2.
Hereinafter, an example of the magnetic recording and reproducing apparatus according to the present embodiment will be described.
Fig. 8 is a schematic perspective view illustrating a part of the magnetic recording and reproducing device according to the embodiment.
FIG. 8 illustrates a head slider.
The magnetic head 110 is provided to a head slider 159. The head slider 159 contains, for example, Al2O3and/TiC, etc. The head slider 159 performs a relative motion with respect to the magnetic recording medium while floating on the magnetic recording medium or contacting the magnetic recording medium.
The head slider 159 has, for example, an air inflow side 159A and an air outflow side 159B. The magnetic head 110 is disposed on the side of the air outflow side 159B of the head slider 159, and the like. Thus, the magnetic head 110 performs relative motion with respect to the magnetic recording medium while floating on or contacting the magnetic recording medium.
Fig. 9 is a schematic perspective view illustrating a magnetic recording and reproducing apparatus according to an embodiment.
Fig. 10(a) and 10(b) are schematic perspective views illustrating a part of the magnetic recording and reproducing device according to the embodiment.
As shown in fig. 9, a rotary actuator is used in the magnetic recording and reproducing device 150 according to the embodiment. The recording medium disk 180 is provided to a spindle motor 180M. The recording medium disk 180 is rotated in the direction of arrow AR by a spindle motor 180M. The spindle motor 180M responds to a control signal from the drive device control section. The magnetic recording and reproducing apparatus 150 according to the present embodiment may include a plurality of recording medium disks 180. The magnetic recording and reproducing device 150 may also include a recording medium 181. The recording medium 181 is, for example, an SSD (Solid State Drive). For example, a nonvolatile memory such as a flash memory is used for the recording medium 181. For example, the magnetic recording and reproducing device 150 may be a hybrid HDD (Hard Disk Drive).
The head slider 159 records and reproduces information recorded on the recording medium disk 180. The head slider 159 is provided at the tip of the film-like suspension 154. The magnetic head according to the embodiment is provided near the tip of the head slider 159.
When the recording medium disk 180 rotates, the pressing force by the suspension 154 and the pressure generated on the medium opposing 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 amount of levitation. In the embodiment, the head slider 159 may be in contact with the recording medium disk 180. For example, a contact movement type may be applied.
The suspension 154 is connected to one end of an arm 155 (e.g., an actuator arm). The arm 155 includes, for example, a wire barrel portion. The bobbin portion holds a driving coil. A voice coil motor 156 is provided at the other end of the arm 155. The voice coil motor 156 is one of linear motors. The voice coil motor 156 includes, for example, a driving 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 opposing yokes. A drive coil is provided between the permanent magnet and the opposing yoke. The suspension 154 has one end and the other end. The magnetic head is disposed at one end of the suspension 154. The arm 155 is connected to the other end of the suspension 154.
The arm 155 is held by a ball bearing. The ball bearings are provided at two positions above and below 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 an arbitrary position on the recording medium disk 180.
Fig. 10(a) is an enlarged perspective view of the head stack assembly 160, illustrating a part of the magnetic recording and reproducing apparatus.
Fig. 10(b) is a perspective view illustrating a head assembly (HGA) 158 which becomes a part of a head stack assembly (head stack assembly) 160.
As shown in fig. 10(a), the head stack assembly 160 includes a bearing portion 157, a head gimbal assembly 158, and a support bracket 161. A head gimbal assembly 158 extends from the bearing portion 157. The support frame 161 extends from the bearing portion 157. The support bracket 161 extends in the opposite direction to the head gimbal assembly 158. The carrier 161 supports a coil 162 of the voice coil motor 156.
As shown in fig. 10(b), the head gimbal assembly 158 has an arm 155 extending from the bearing portion 157, and a suspension 154 extending from the arm 155.
A head slider 159 is provided on the top end of the suspension 154. The head slider 159 is provided with the magnetic head according to the embodiment.
