JPH0444803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a magnetic head that performs recording or reproduction perpendicularly to a recording medium.

Conventional configurations and their problems Perpendicular magnetization recording has been proposed as a method for performing high-density magnetic recording (for example,
134706, JP-A-53-3209). This method has the feature that the demagnetizing field of the recorded magnetization is small and enables high-density magnetic recording, but it requires a recording medium with perpendicular anisotropy and a perpendicular magnetic recording head with a strong perpendicular magnetic field. shall be. 1st
The figure shows an example of a conventional perpendicular magnetic recording head. A magnetic recording medium 3 having a medium high permeability layer 2 under a magnetization layer 1 having perpendicular magnetic anisotropy
A main magnetic pole 6 in which a high magnetic permeability thin film 4 is sandwiched between non-magnetic materials 5 is provided in close proximity to the magnetized layer 1, and a coil 7 is wound around the main magnetic pole 6 to provide electrical input or output for perpendicular magnetic recording or Perform playback. In the conventional head with this configuration, the recording medium is in the magnetic flux passing through the magnetic circuit 8 formed by the current flowing through the coil 7, and the magnetic layer 1
A portion close to the high magnetic permeability thin film 4 is magnetized and recorded. Conversely, during reproduction, the magnetic flux due to the magnetization of the portion of the magnetic layer 1 that is close to the high magnetic permeability thin film 4 flows through the magnetic circuit 8, interlinks the coil 7, and is output from the coil 7 as an electrical signal. . Here, in the conventional magnetic head, since the magnetic circuit 8 has a large magnetic resistance, the conventional magnetic head has a disadvantage of poor efficiency both during recording and reproduction. There are three reasons why the magnetic resistance increases. The first is that the high magnetic permeability thin film 4 is generally thick.
This is because although it is thin at about 1 μm, it is several mm long, so even if it is made of a high magnetic permeability material such as permalloy, the magnetic resistance will be large. The second reason is that the magnetic circuit 8 is formed from the high magnetic permeability thin film 4 to the medium high magnetic permeability layer 2 through air having low magnetic permeability, so that the magnetic resistance increases. Furthermore, the third cause is that the thickness of the medium high magnetic permeability layer 2 is 1 μm or less and the length of the portion that becomes a part of the magnetic circuit 8 is several mm, which increases the magnetic resistance.

As mentioned above, conventional perpendicular magnetic recording heads have a drawback of high magnetic resistance, which has the drawback of poor recording or reproducing efficiency.

Furthermore, the conventional example described above has the disadvantage that it is susceptible to the influence of external magnetic fields. This situation is shown in FIG.
In the figure, the same parts as in FIG. 1 are indicated with the same numbers. The unnecessary noise magnetic field from the outside interlinks the coil 7 through the magnetic circuit 9 and becomes electrical signal noise from the coil 7 as external noise. This is considered to be because the high magnetic permeability thin film 4 serves as an antenna for external noise magnetic fields.

As described above, magnetic heads of conventional configurations have drawbacks in terms of recording/reproducing efficiency and the influence of external magnetic fields.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to provide a magnetic head that greatly improves recording or reproducing efficiency and eliminates the drawback of being susceptible to external noise magnetic fields. be.

Structure of the Invention The present invention achieves the above object, and includes providing a high permeability magnetic thin film in close proximity to a magnetic recording medium having a high permeability layer under a magnetization layer having perpendicular magnetic anisotropy. A main magnetic pole having a structure in which a portion of a magnetic thin film close to the magnetization layer is sandwiched by at least a nonmagnetic material, and at least a first high magnetic permeability material is magnetically connected to the high permeability magnetic thin film. a second high magnetic permeability body provided close to or connected to the main magnetic pole; and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium in between. The area of the opposing portions of the second and third high magnetic permeability bodies is Su, and the area of the second and third high magnetic permeability bodies is Su,
Let the average distance between the high magnetic permeability materials be u, the first and second
When the area of the opposing parts of the high magnetic permeability bodies is Sv, and the average distance between the first and second high magnetic permeability bodies is v, it is assumed that v/Sv>u/Su. The present invention provides a magnetic head with the following characteristics.

DESCRIPTION OF EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 3 shows a sectional view of a magnetic head according to an embodiment of the present invention, and the same parts as in FIG. 1 are designated by the same numbers.

In this embodiment, a high magnetic permeability thin film 4 is provided adjacent to a magnetic recording medium 3 consisting of a magnetic layer 1 and a medium high permeability layer 2, and a first high magnetic permeability block 10 is provided connected to a part of the thin film 4. , a main magnetic pole 6 including a tip portion 17 sandwiched between nonmagnetic materials 5 is provided at a portion of the high magnetic permeability thin film 4 near the magnetic recording medium 3 . A second high magnetic permeability block 11 is placed adjacent to the main magnetic pole 6 on the magnetic recording medium 3.
Provided on the main magnetic pole 6 side. Furthermore, a third high magnetic permeability block 12 is provided on the opposite side of the main magnetic pole 6 of the magnetic recording medium 3.
will be established. A coil 7 is wound around the main pole 6.

FIG. 4 is an enlarged view of the main pole tip 12 of the magnetic head shown in FIG. In Figure 4, the second
The area of the opposing parts of the third high magnetic permeability bodies 11 and 12 is Su, the average distance between them is u, and the area of the opposing parts of the first and second high magnetic permeability bodies 10 and 11 is Sv, When the average distance between the two is v, it is constructed so that v/Sv>u/Su.

The effects of this embodiment with such a configuration will be described. By providing the first high magnetic permeability block 10 magnetically connected to the high magnetic permeability thin film 4, the magnetic resistance of the high magnetic permeability thin film 4 can be significantly reduced.
Furthermore, by providing the second high magnetic permeability block 11 near or connected to the main magnetic pole 6 on the main magnetic pole 6 side of the magnetic recording medium 3, a magnetic circuit 13 is formed, and the magnetic circuit 13 can pass through the air. There was no magnetic resistance, and the magnetic resistance could be significantly reduced. Furthermore, by providing the third high magnetic permeability block 12 on the opposite side of the main magnetic pole 6 of the magnetic recording medium 3, the magnetic circuit 1
3 can shorten the distance through the medium high permeability layer 2,
The effect of significantly lowering the magnetic resistance of the medium high permeability layer 2 was obtained.

Furthermore, in this embodiment, in order to reduce the influence of external noise magnetic fields, it is desirable that the magnetic resistance of the magnetic circuit 16 in FIG. , for this purpose a first high permeability block 1
0 and the second high permeability block 11 is preferably greater than the reluctance between the second high permeability block 11 and the third high permeability block 12.

Therefore, the magnetic resistance between the first high magnetic permeability block 10 and the second high magnetic permeability block 11 is reduced by the magnetic resistance between the second high magnetic permeability block 11 and the third high magnetic permeability block 12.
It is sufficient to set the magnetic resistance to be larger than the magnetic resistance between the two. Since magnetic resistance is inversely proportional to area and proportional to length, the above condition is given by the following equation.

v/Sv>u/Su In other words, the first,
When the second and third high permeability blocks are placed,
The influence of external noise is small, and the recording/reproducing efficiency of the head is high.

FIG. 5 is a sectional view of the magnetic head for explaining that the configuration of this embodiment is less affected by external noise magnetic fields. In FIG. 5, the external noise magnetic field mainly passes through the magnetic circuit 14 with low magnetic resistance, and a small amount passes through the magnetic circuits 15 and 16 with high magnetic resistance, so that the external noise magnetic field as a whole links the coil 7. This greatly reduces the influence of external noise.

Specifically, the high magnetic permeability thin film 4 is made of an amorphous material whose main components are Co and Zu, which have higher saturation magnetization and higher magnetic permeability, such as CoZrNb or CoFeZrNb, in addition to permalloy, which is commonly used in the past. It is formed by sputtering to about 1 μm, and the length of the main pole tip portion 17 is about 100 μm. The first high magnetic permeability block 10 is made of ferrite material and has a thickness of about 100 μm and a length of about 5 mm. The second high magnetic permeability block 11 is made of ferrite material or the like, and is configured to be sufficiently larger than the first high magnetic permeability block 10 to reduce the magnetic resistance of the space. The third high magnetic permeability block 12 on the rear surface of the medium also has a large surface facing the second high magnetic permeability block 11 to reduce magnetic resistance, and is made of ferrite material or the like.

Effects of the Invention In summary, the present invention provides a high permeability magnetic thin film in close proximity to a magnetic recording medium having a high permeability layer under a magnetic layer having perpendicular magnetic anisotropy, and a main magnetic pole having a structure in which a portion adjacent to the magnetization layer is sandwiched by at least a non-magnetic material and has at least a first high magnetic permeability material magnetically connected to the high magnetic permeability magnetic thin film; A second high magnetic permeability body provided adjacent to or connected to the second high magnetic permeability body, and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium in between. The area of the opposing portion of the third high magnetic permeability body is Su, the average distance between the second and third high magnetic permeability body is u, and the opposing portion of the first and second high magnetic permeability body A magnetic circuit of a magnetic head characterized in that it is configured such that v/Sv>u/Su, where Sv is the area of the magnetic head and v is the average distance between the first and second high magnetic permeability bodies It has the advantage of lowering resistance, increasing recording or reproducing efficiency, and reducing the influence of external noise magnetic fields.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional perpendicular magnetic head;
FIG. 3 is a sectional view of a conventional perpendicular magnetic head showing the influence of an external noise magnetic field. FIG. 3 is a sectional view of a magnetic head according to an embodiment of the present invention. FIG. The enlarged view, FIG. 5, is a sectional view of the magnetic head showing the influence of an external magnetic field on the magnetic head of the present invention. 1...Magnetization layer, 2...Medium high permeability layer, 3...
Magnetic recording medium, 4... High magnetic permeability thin film, 5... Nonmagnetic material, 6... Main magnetic pole, 7... Coil, 8, 9, 1
3, 14, 15, 16...Magnetic circuit, 10...First high magnetic permeability block, 11...Second high magnetic permeability block, 12...Third high magnetic permeability block, 1
7... Main magnetic pole tip.

Claims (1)

[Scope of Claims] 1. A high permeability magnetic thin film is provided adjacent to a magnetic recording medium having a high magnetic permeability layer under a magnetization layer having perpendicular magnetic anisotropy, and the magnetization of the high permeability magnetic thin film is a main magnetic pole having a structure in which a portion adjacent to the layer is sandwiched by at least a non-magnetic material and has at least a first high magnetic permeability material magnetically connected to the high magnetic permeability magnetic thin film; and a main magnetic pole adjacent to the main magnetic pole. and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium in between, The area of the opposing portions of the high magnetic permeability bodies is Su, the average distance between the second and third high magnetic permeability bodies is u, and the area of the opposing portions of the first and second high magnetic permeability bodies is Sv,
A magnetic head characterized in that, where v is the average distance between the first and second high magnetic permeability bodies, v/Sv>u/Su. 2. The magnetic head according to claim 1, wherein the high permeability magnetic thin film is made of an amorphous material containing Co and Zr as main components. 3. The magnetic head according to claim 1, wherein the high permeability magnetic thin film is made of an amorphous material containing Co, Fe, Zr, and Nb.