JPH0836714A - Magnetoresistive element, magnetic head and magnetic recording device - Google Patents

Abstract

(57) [Summary] [Purpose] To suppress Barkhausen noise with a simple configuration. [Structure] An exchange coupling film 13 is provided between the magnetoresistive film 14 and the magnetic domain control film 12. The exchange coupling film 13 is
The magnetic domain control film 12 has a property that it is not easily affected by air, water, etc. that change the surface state of the magnetic domain control film 12, and the magnetoresistive film 14 and the magnetic domain control film 12 are magnetically exchange-coupled to each other. There is. The magnetic domain of the magnetoresistive film 14 is
It is controlled by the magnetic domain control film 12 via the exchange coupling film 13. [Effect] Barkhausen noise can be suppressed with a simple configuration. A magnetic head and a magnetic recording device with improved reliability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetoresistive effect element,
Regarding the magnetic head and the magnetic recording device, more specifically,
The present invention relates to a magnetoresistive effect element capable of effectively suppressing Barkhausen noise, and a magnetic head and a magnetic recording device using the magnetoresistive effect element.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for miniaturization and large capacity of magnetic recording devices. Accordingly, in order to improve recording density, "recording / reproducing separated type recording / reproducing separated type" is performed in which optimized elements are used. The need for magnetic heads is growing. Since a magnetoresistive effect element (magnetoresistive element) using a magnetoresistive effect film is suitable as a reproducing element of this kind of magnetic head, researches on it are actively conducted.

However, it is known that "Barkhausen noise" is liable to occur in the magnetoresistive element, which causes distortion in the reproduced signal waveform and changes in its peak value and base line. (For example,
Journal of Appli
ed physics), Volume 52 (3), Pages 2465-2467 (1
981), "The origin Barkhausen noise in
small permalloy magnetoresistive sensors ").

It is known that "Barkhausen noise" is caused by the domain wall of the magnetoresistive effect film (MR film) (for example, Journal of Applied Physics, Vol. 55 (6)). , No. 2226-2231 (1984)
Year))). This phenomenon will be described below by taking a NiFe film, which is a typical magnetoresistive film, as an example. Since the NiFe film is a ferromagnetic film, the magnetostatic energy
A return domain structure is likely to be formed in an attempt to stabilize the magnetic field.
In the reflux magnetic domain structure, the magnetic wall
Ment cannot rotate continuously, this N
When an external magnetic field is applied to the iFe film, the external magnetic field-magnetic resistance curve fluctuates (jumps) due to the discontinuous rotation of the magnetic moment. This fluctuation is detected as noise in the magnetoresistive output of the NiFe film. Therefore, in order to suppress Barkhausen noise, it is essential to maintain the NiFe film in a single domain state without domain walls.

Conventionally, as one of the methods of suppressing Barkhausen noise, there is a method of providing a "domain control film" adjacent to the magnetoresistive film. This magnetic domain control film is made of a unidirectionally magnetized ferromagnetic material or antiferromagnetic material, and maintains the magnetoresistive effect film in a single magnetic domain state by magnetic exchange coupling with the magnetoresistive effect film. Is. 7A and 7B show the structure of the magnetic sensing portion of the conventional magnetoresistive effect magnetic head adopting this suppression method.

In the conventional magnetic head 50a shown in FIG. 7A, a substantially rectangular magnetic domain control film 52 having the above-described function is formed on a substrate 51, and a substantially rectangular magnetoresistive effect film 5 is formed thereon.
4 is further formed. The magnetic domain control film 52 is formed over the entire surface of the magnetoresistive effect film 54. The magnetoresistive film 54 is kept in a single magnetic domain state by the magnetic domain control film 52 magnetized in one direction. A substantially rectangular separation film 55 and a SAL film 56 are formed in this order on the magnetoresistive film 54, and a pair of electrodes 57 are formed on the SAL film 56.

The conventional magnetic head 50b shown in FIG.
The conventional magnetic head 5 of FIG. 7A except that the magnetic domain control film 52 is formed only on both ends of the reproducing track portion.
It has the same structure as 0a. The magnetoresistive film 54 is in direct contact with the substrate 51 in the central portion of the reproduction track portion. The configuration of FIG. 7B is adopted to improve the sensitivity only in the reproduction track section.

[0008]

However, in the above-described conventional magnetoresistive effect magnetic heads 50a and 50b, despite the provision of the magnetic domain control film 52 adjacent to the magnetoresistive effect film 54, Barkhausen noise is generated. There is a problem that it may not be able to suppress sufficiently.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetoresistive element capable of reliably suppressing Barkhausen noise with a simple structure.

Another object of the present invention is to provide a magnetoresistive effect magnetic head and a magnetic recording device having improved reliability as compared with the conventional one.

[0011]

[Means for Solving the Problems]

(1) A magnetoresistive effect element according to the present invention is a magnetoresistive effect element comprising a magnetoresistive effect film and a magnetic domain control film for controlling a direction of magnetization of the magnetoresistive effect film. It has an exchange coupling film formed between the magnetic domain control film, the exchange coupling film has a property of being less susceptible to a substance that changes the surface state of the magnetic domain control film, The magnetoresistive film and the magnetic domain control film are magnetically exchange-coupled with each other, and the magnetic domain of the magnetoresistive film is controlled by the magnetic domain control film via the exchange coupling film. And

The magnetoresistive film is not particularly limited, and any film having a magnetoresistive effect can be used. Preferred are, for example, NiFe,
Co-Ni-Fe, Co-Cr, Co-Ni, Fe-C
r, Ni-Cu, etc. are mentioned.

As the magnetic domain control film, any film can be used as long as it has a function of controlling the magnetization direction of the magnetoresistive film. Preferred examples include ferromagnetic materials and antiferromagnetic materials used as permanent magnets.

Specifically, in a ferromagnetic material, for example, Co
Binary alloys such as Pt, CoNi, CoCr, CoIr, SmCo, CoCrTi, CoCrPt, CoCr
There are ternary alloys such as Ta, CoCrZr, CoNiTi, and CoNiZr, and quaternary alloys such as CoCrTaPt. ◆ For antiferromagnetic materials, for example, FeM
n, NiO, etc. The thicknesses of the magnetoresistive film and the magnetic domain control film are not particularly limited, and may be appropriately adjusted as needed.

(2) The exchange coupling film has a property that it is not easily affected by a substance that changes the surface state of the magnetic domain control film, and the magnetoresistive effect film and the magnetic domain control film are respectively provided. Any magnetically exchange-coupling type can be used.

The substance that changes the surface state of the magnetic domain control film is a substance with which the magnetic domain control film may come into contact in the film forming step, and the contact causes a change in the surface state of the magnetic domain control film. Means For example, air,
Water, photoresist, developer, etc.

The preferred exchange coupling membrane is F
It is a film made of at least one element selected from the group consisting of e, Ni and Co. This film may be a metal film made of any one of Fe, Ni and Co, or F
An alloy film containing any one of e, Ni and Co as a main component may be used. This is because these have good soft magnetic characteristics and are easy to apply a bias magnetic field.

Preferred examples of at least one element selected from the group consisting of Fe, Ni and Co include, for example, Ni, Ni-Fe, Co-Ni-Fe,
Co-Cr, Co-Ni, Fe-Cr, Ni-Cu and the like. This is because these are conductive ferromagnetic materials and have a property that the oxidation does not proceed much even if the surface is exposed to the atmosphere.

Particularly preferable materials for the exchange coupling film are Ni _1-X Fe _X (0 <x ≦ 0.3) alloy film and Ni film. This is because these have a large coercive force and good magnetic exchange coupling can be obtained between the magnetoresistive film and the magnetic domain control film. When x exceeds 0.3, the saturation magnetic flux density becomes low, which is not preferable.

The thickness t of the exchange coupling film can be arbitrarily set as long as good magnetic exchange coupling can be obtained between the magnetoresistive effect film and the magnetic domain control film. However, it is preferably in the range of 3 nm or more and 12 nm or less. This is because the coercive force becomes small when the thickness is less than 3 nm or exceeds 12 nm.

The product of the thickness t of the exchange coupling film and the saturation magnetic field Bs is 3 (T · nm) ≦ Bs · t ≦ 12 (T · nm).
It is preferably within the range. This is because within this range, the coercive force of a predetermined value or more (for example, 800 Oe or more) necessary for ensuring the function of the exchange coupling film can be maintained.

The magnetoresistive effect element of the present invention is preferably used for a magnetic head, but it can also be used for other purposes such as a magnetic field detector.

(3) The magnetoresistive effect magnetic head according to the present invention is characterized by including the magnetoresistive effect element according to the above (1) or (2). ◆ This magnetic head is preferably of a composite type in which it is combined with an inductive recording element.

(4) The magnetic recording apparatus of the present invention is characterized by including the magnetic head of the above (3). This magnetic recording device can be realized as any device that magnetically records / reproduces information, such as a magnetic disk device and a magnetic tape device.

[0025]

In order to suppress Barkhausen noise, it is necessary that the magnetoresistive film and the magnetic domain control film are magnetically sufficiently exchange-coupled. However, depending on the type of the magnetic domain control film and the film forming process, stable magnetic exchange coupling may not be generated between the magnetic domain control film and the magnetoresistive effect film.
For example, when the magnetic domain control film and the magnetoresistive effect film are formed by separate film forming devices, or the formed magnetic domain control film is patterned by photolithography and then the magnetoresistive effect film is formed thereon. This is the case. As a result of the inventor's earnest study on this problem, the cause is that the surface of the magnetic domain control film is exposed to air, water, a photoresist, a developing solution, etc. in the process of moving between film forming devices and the photolithography process. It was found that the surface condition of the magnetic domain control film is changed by it.

In the magnetoresistive effect element of the present invention, since the exchange coupling film is provided between the magnetoresistive effect film and the magnetic domain control film, the film forming apparatus is formed after forming the exchange coupling film on the magnetic domain control film. It is possible to prevent a substance, such as air, that changes the surface state of the magnetic domain control film from coming into contact with the surface of the magnetic domain control film by moving between the two or performing photolithography.

Since the exchange coupling film is not easily affected by a substance that changes the surface state of the magnetic domain control film, the magnetoresistive film is formed on the exchange coupling film after the transfer process between the film forming devices and the photolithography process. When the effect film is formed, stable magnetic exchange coupling is secured between the exchange coupling film and the magnetoresistive effect film.

Since the exchange coupling film is also magnetically exchange-coupled with the magnetic domain control film, the magnetization direction of the magnetoresistive film can be controlled by the magnetoresistive film via the exchange coupling film. Therefore, it is possible to reliably suppress Barkhausen noise with a simple configuration in which an exchange coupling film is provided between the magnetoresistive film and the magnetic domain control film.

Since the magnetic head of the present invention includes the magnetoresistive effect element of the present invention, Barkhausen noise is surely suppressed, and as a result, a highly reliable magnetoresistive effect magnetic head can be obtained. Since the magnetic recording apparatus of the present invention includes the magnetic head of the present invention, Barkhausen noise is reliably suppressed, and as a result, reliability is improved.

Is improved.

[0031]

Embodiments of the present invention will be described below with reference to the accompanying drawings. [First Embodiment] FIG. 1 is a conceptual diagram of a magnetoresistive effect element according to the first embodiment of the present invention.

In this magnetoresistive element, the non-magnetic substrate 1
1, a magnetic domain control film 12 magnetized in one predetermined direction is formed, and an exchange coupling film 13 and a magnetoresistive effect film 14 are sequentially stacked on the magnetic domain control film 12. The magnetic domain control film 12 and the exchange coupling film 13 are formed only on both ends of the reproducing track portion in order to improve the sensitivity of only the reproducing track portion.

The magnetic domain control film 12 and the exchange coupling film 13 arranged at both ends of the reproducing track portion both have a substantially rectangular pattern. The magnetoresistive effect film 14 formed on the exchange coupling film 13 also has a rectangular pattern, but it is formed between the magnetic domain control film 12 and the exchange coupling film 13 arranged at both ends of the reproducing track portion. It is formed to straddle. As a result, the magnetoresistive film 14 is in contact with the substrate 11 at the center of the reproduction track portion. The shape of the magnetoresistive film 14 is, for example, 20 μm on the long side and 3 μ on the short side.
It is a rectangle of m.

In the magnetoresistive effect element of FIG. 1, as the magnetic domain control film 12, C containing 20 at% Pt, which is a ferromagnetic material, is used.
An o alloy film, that is, a Co-20 at% Pt alloy film (film thickness 60 nm) is used. As the magnetoresistive film 14, a Fe alloy film containing 20 at% Ni which is a ferromagnetic material, that is, a Fe-20 at% Ni alloy film (film thickness 20 n
m) is used.

As the exchange coupling film 13, the same Fe-20 at% Ni alloy film as the magnetoresistive film 14 is used. However, the film thickness is 5.8 nm, which is much thinner than the magnetoresistive film 14.

The magnetic domain control film 12 made of the Co-20 at% Pt alloy film is magnetically exchange-coupled with the exchange coupling film 13 made of the Fe-20 at% Ni alloy film, and the exchange coupling film 13 is also formed. Is magnetically exchange-coupled with the magnetoresistive film 14 made of an Fe-20 at% Ni alloy film. Therefore, it can be said that the magnetic domain control film 12 is magnetically exchange-coupled with the magnetoresistive effect film 14 via the exchange coupling film 13, and as a result, the magnetoresistive effect film 1 is obtained.
The direction of the magnetic domain of No. 4 is controlled by the magnetic domain control film 12 magnetized in one predetermined direction, and is kept in a predetermined single magnetic domain state.

Fe-20 at% as the exchange coupling film 13
The Ni alloy film has a property that it is difficult to be oxidized even if it is exposed to air or water. Therefore, after the exchange coupling film 13 is formed on the magnetic domain control film 12, the exchange coupling film 13 protects it from air, water, etc.
There is no fear that the surface of the magnetic domain control film 12 made of the% Pt alloy film is changed by air, water, or the like.

A separation film 15 is formed on the magnetoresistive film 14.
And the SAL film 16 are formed in this order.
Further, a pair of electrodes 17 is formed on the top surface of. The separation film 15 and the SAL film 16 are formed over the entire surface of the magnetoresistive film 14 having a rectangular pattern. The pair of electrodes 17 are arranged above the magnetic domain control film 12 and the exchange coupling film 13 arranged at both ends of the reproducing track portion, respectively.

The separation film 15 is formed of a Ta film (film thickness 10 nm) or the like, the SAL film 16 is formed of a NiFeNbCo film (film thickness 10 nm) or the like, and the pair of electrodes 17 is formed.
Is formed of an Au film (film thickness 0.2 μm) or the like.

The magnetoresistive effect element having the above structure is manufactured as follows. ◆ First, RF (Radio Freque
A Co-20 at% Pt alloy film as the magnetic domain control film 12 is formed on the substrate 11 by the ncy) sputtering method. Next, after transferring to another film forming apparatus, EB (Electron
Beam) vapor deposition, and Fe-20 at% Ni as the exchange coupling film 13 is formed on the Co-20 at% Pt alloy film.
An alloy film is formed.

Fe-20 at% Ni in the EB evaporation method
The film forming conditions of the alloy film are, for example, ultimate vacuum: 1.4 × 10 ⁴ Pa, input power: 1.2 to 1.4 W / m ^2, film forming rate: 0.4 nm / s, substrate temperature: 260 ° C. To do.

Then, the Co-20 at% Pt alloy film and the Fe-20 at% Ni alloy film are patterned by photolithography and ion milling to form a substantially rectangular pattern arranged at both ends of the reproduction track portion. The magnetic domain control film 12 and the exchange coupling film 13 are formed.

In this magnetoresistive effect element, Fe-20a
Since the exchange coupling film 13 made of a t% Ni alloy film has a property of being hard to be oxidized even if it is exposed to air or water, Co
The magnetic domain control film 12 made of a -20 at% Pt alloy film is protected by the exchange coupling film 13 from air, water, photoresist, developing solution and the like. As a result, the surface of the magnetic domain control film 12 is oxidized by air, water, or the like in the process of moving between the film forming apparatuses and the photolithography process as in the conventional case, and an oxide film is generated on the surface of the magnetic domain control film 12. There is no fear of

Next, by the high frequency bipolar sputtering method, on the patterned exchange coupling films 13 at both ends of the reproducing track portion, the magnetoresistive effect is provided so as to extend between the exchange coupling films 13. Fe-20 at% as the film 14
A Ni alloy film is formed.

After that, Fe-20a was formed by a known method.
A film for the separation film 15 and a film for the SAL film 16 are sequentially formed on the t% Ni alloy film. Then, the magnetoresistive effect film 14, the isolation film 15 and the SAL film 16 are patterned in a rectangular shape by photolithography and etching. After that, a metal film for the electrodes 17 is formed on the SAL film 16 and then patterned into a predetermined shape to form a pair of electrodes 17. In this way, the magnetoresistive effect element of FIG. 1 is obtained.

As described above, in the magnetoresistive effect element of FIG. 1, since the exchange coupling film 13 is provided between the magnetoresistive effect film 14 and the magnetic domain control film 12, the exchange coupling is formed on the magnetic domain control film 12. It is possible to prevent a substance such as air that changes the surface state of the magnetic domain control film 12 from coming into contact with the surface of the magnetic domain control film 12 by moving the film formation apparatus or performing photolithography after forming the film 13. it can.

Since the exchange coupling film 13 is not easily affected by the substance that changes the surface state of the magnetic domain control film 12,
When the magnetoresistive effect film 14 is formed on the exchange coupling film 13 after the transfer process between the film forming devices and the photolithography process, a stable magnetic field is formed between the exchange coupling film 13 and the magnetoresistive effect film 14. Exchange coupling is secured.

Since the exchange coupling film 13 is also magnetically exchange-coupled with the magnetic domain control film 12, the direction of magnetization of the magnetoresistive effect film 14 is determined by the exchange coupling film 13.
2, the magnetoresistive film 14 is maintained in a single domain structure. As a result, Barkhausen noise can be surely suppressed.

The magnetoresistive effect element of FIG. 1 was actually manufactured,
Magnetization characteristics of the magnetoresistive effect film 14 and the magnetoresistive effect film 14
The dependence of the coercive force Hc of the above on the thickness of the exchange coupling film 13 was investigated. The results are shown in FIGS. 2 and 3, respectively.

The magnetization curve (M
From the -H loop), it was confirmed that the magnetoresistive effect film 14 of this example was magnetically reversed together with the magnetic domain control film 12. This indicates that the magnetoresistive effect film 14 and the magnetic domain control film 12 are sufficiently magnetically exchange-coupled via the exchange-coupling film 13.

Further, when the magnetic head is used, it is affected by an external magnetic field such as a leakage magnetic field from the magnetic recording medium. Therefore, in order to ensure a stable operation of the magnetic head, the magnetoresistive effect film 14 is, for example, 800 Oe or more. It is necessary to have a coercive force Hc. From this viewpoint, when the graph of FIG. 3 is viewed, the thickness t of the exchange coupling film 13 is 3 nm to 12 nm.
It turns out that it must be in the range.

Therefore, Fe used as the exchange coupling film 13
Considering that the saturation magnetic flux density Bs of the −20 at% Ni alloy film is 1 T, the product of Bs and the film thickness t of the exchange coupling film 13 is 3 (T · nm) ≦ Bs · t ≦ 12 (T · nm)
It can be seen that the range is preferable.

When an external magnetic field was applied to this magnetoresistive element and the response to the external magnetic field was measured, Barkhausen noise was not observed. Therefore, it was confirmed that Barkhausen noise can be reliably suppressed by this magnetoresistive effect element.

In this embodiment, the magnetic domain control film 12 and the exchange coupling film 13 are formed only at both ends of the track width portion as shown in FIG. 7B, but as shown in FIG. 7A. To
Of course, it may be formed over the entire track width portion.

[Comparative Example] A magnetoresistive element having the same structure as that of FIG. 1 was prepared except that the exchange coupling film 13 was not present, and the magnetization characteristics were examined. A magnetization curve separated from the effect film 14 was obtained. This is because the magnetic domain control film 12 causes the magnetoresistive film 1
4 means that the magnetic domain control was not performed. The reason for this is the transfer process between film forming devices and photolithography.
This is because the magnetic exchange coupling between the magnetic domain control film 12 and the magnetoresistive effect film 14 is extremely weakened by the oxide film formed on the surface of the magnetic domain control film 12 in the process.

[Second Embodiment] FIG. 4 shows a magnetoresistive head according to a second embodiment of the present invention. The magnetoresistive effect element of this magnetic head has the same structure as the magnetoresistive effect element of the first embodiment except that the substrate 11 is not present.

A shield film 18 is formed below the magnetoresistive effect element via a gap layer, and a shield film 19 is formed above the magnetoresistive effect element via a gap layer. . The shield films 18 and 19 are formed of a permalloy alloy film (film thickness 1 μm) and are effective for increasing the resolution of the magnetoresistive effect element. A pair of electrodes 17
Is formed of a Cu film (film thickness 100 nm), and both gap layers are formed of an Al ₂ O ₃ layer (film thickness 100 nm).

When the response of this magnetic head to an external magnetic field was measured, Barkhausen noise was not observed, as in the first embodiment. ◆ Replace the exchange coupling film 13 with F
e-20 at% Ni alloy film instead of Ni ₉₀ -Cu ₁₀ , C
_{o 10 -Ni 80 -Fe 10, Co} 90 -Cr 10, Co 90 -Ni
_The response to the external magnetic field was measured in the same manner using an alloy film of ₁₀ , ₁₀ , Fe ₉₀ -Cr _10, etc., but also in these cases, Barkhausen noise was not observed.

[Third Embodiment] FIG. 5 shows a magnetoresistive head according to a third embodiment of the present invention. This head is of a recording / reproducing separated type, and its magnetoresistive effect element has the same structure as the magnetoresistive effect element of the first embodiment except that the substrate 11 does not exist.

A shield film 18 is formed on a slider base body 20 made of a sintered body containing Al ₂ O ₃ .TiC as a main component. Above the shield film 18, a gap layer ( A magnetoresistive effect element having substantially the same configuration as that of FIG. 1 is formed via (not shown). A shield film 19 is formed above the magnetoresistive element via a gap layer (not shown). A pair of recording magnetic poles 21 and 22 are formed above the shield film 19 with a gap layer (not shown) interposed therebetween, and a coil 23 is formed between the recording magnetic poles 21 and 22. There is.

The film thickness of the magnetoresistive effect element is 100 nm, and its magnetic sensitive portion is a square having a side length of 2 μm. The shield layers 18 and 19 are both formed of a Ni—Fe alloy film (film thickness 1 μm) and have the function of increasing the resolution of the magnetoresistive effect element. The pair of electrodes 17 is formed of a Cu film (film thickness 100 nm). A Cu film (thickness: 3 μm) is formed between the pair of recording magnetic poles 21 and 22.
m) and their spacing is about 0.4 μm. The coil 23 is formed of a Cu film (thickness 3 μm).

The gap layer between the shield film 18 and the magnetoresistive effect element, the magnetoresistive effect element and the shield film 19 are provided.
The gap layer between the _two is formed of an Al ₂ O ₃ layer (film thickness 1 μm). The gap layer between the shield film 19 and the recording magnetic pole 21 is also formed of an Al ₂ O ₃ layer (film thickness of about 4 μm). The space between the pair of recording magnetic poles 21 and 22 is filled with an Al ₂ O ₃ layer.

In this magnetic head, the magnetoresistive effect element functions as a reproducing element, and the coil 34 and the pair of recording magnetic poles 21.
And 22 serve as recording elements. ◆ When this magnetic head was actually manufactured and the recording / reproducing characteristics were evaluated, good output without Barkhausen noise was obtained.

[Fourth Embodiment] FIGS. 6A and 6B.
Shows a magnetic disk device 30 of a fourth embodiment of the present invention. In FIG. 6, 31 is a magnetic disk, 32 is a magnetic disk drive unit that rotates the magnetic disk 31 at high speed, and 33
Is a magnetic head, 34 is a magnetic head drive unit for moving and positioning the magnetic head 33, and 35 is the magnetic head 33.
Is a recording / reproducing signal processing system for processing a recording / reproducing signal transmitted between a recording / reproducing signal and an external signal source. This magnetic disk device 30 includes 1-9 magnetic disks 31 and 2-18.
The magnetic head 33 is provided.

This magnetic disk device 30 was actually manufactured as follows. As the magnetic head 33, the recording / reproducing separated type magnetic head 10 described in the third embodiment was used. As the magnetic disk 31, a NiP-plated Al substrate having a diameter of 2.5 inches was used, and C having a film thickness of 50 nm as a characteristic improving film
A magnetic disk in which an r film, a CoCrTa film having a film thickness of 30 nm as a recording film are formed, and a C protective film having a film thickness of 15 nm and a perfluoroalkylpolyether lubricating film having a film thickness of 5 nm are further formed thereon. Was used. The coercive force of this magnetic disk was 2500 Oe.

When the recording / reproducing characteristics of this magnetic disk device 30 were evaluated, good output without Barkhausen noise was obtained. As a result, good recording / reproducing characteristics were stably obtained even at a high recording density of 1 Gb / in ² or more.

The magnetic disk 31 has a diameter of 1.
CoCrPt, CoCrPt on 8 inch glass substrate
Similar results were obtained using a magnetic layer such as B.

[0068]

According to the magnetoresistive effect element of the present invention,
Barkhausen noise can be reliably suppressed with a simple configuration. According to the magnetic head of the present invention, it is possible to obtain a magnetic resistance effect type magnetic head having improved reliability as compared with the conventional one. According to the magnetic recording device of the present invention, it is possible to obtain a magnetic recording device having improved reliability as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a conceptual sectional view of a magnetoresistive effect element according to a first embodiment of the present invention.

FIG. 2 is a graph showing the magnetization characteristics of the magnetoresistive effect film of the magnetoresistive effect element of the first example.

FIG. 3 is a graph showing the dependence of the coercive force of the magnetoresistive effect film of the magnetoresistive effect element of the first embodiment on the thickness of the exchange coupling film.

FIG. 4 is a schematic perspective view showing a magnetoresistive effect magnetic head according to a second embodiment of the invention.

FIG. 5 is a schematic perspective view showing a composite type magnetic head according to a third embodiment of the invention.

6A is a schematic plan view of a magnetic disk device according to a fourth embodiment of the present invention, and FIG. 6B is a schematic sectional view thereof.

FIG. 7 is a conceptual cross-sectional view showing a conventional magnetoresistive effect magnetic head.

[Explanation of symbols]

 10 magnetic head 11 substrate 12 magnetic domain control film 13 exchange coupling film 14 magnetoresistive effect film 15 separation film 16 SAL film 17 electrode 18, 19 shield film 20 substrate 21, 22 recording magnetic pole 23 coil 30 magnetic disk device 31 magnetic disk 32 magnetic disk Drive unit 33 Magnetic head 34 Magnetic head drive unit 35 Recording / reproducing signal processing system 50a, 50b Magnetic head 51 Substrate 52 Magnetic domain control film 54 Magnetoresistive film 55 Separation film 56 SAL film 57 Electrode

Claims (8)

[Claims] 1. A magnetoresistive effect element comprising a magnetoresistive effect film and a magnetic domain control film for controlling the direction of magnetization of the magnetoresistive effect film, wherein a magnetoresistive effect film is provided between the magnetoresistive effect film and the magnetic domain control film. And an exchange coupling film formed on the magnetic recording medium, the exchange coupling film having a property of being less susceptible to a substance that changes the surface state of the magnetic domain control film, and the magnetoresistive film and the magnetic resistance effect film. A magnetoresistive effect element, which is magnetically exchange-coupled with a magnetic domain control film, wherein the magnetic domain of the magnetoresistive film is controlled by the magnetic domain control film via the exchange coupling film. 2. The exchange coupling film is made of Fe, Ni and C.
The magnetoresistive effect element according to claim 1, which is a film made of at least one element selected from the group consisting of o. 3. The magnetoresistive effect element according to claim 1, wherein the exchange coupling film is a Ni film. 4. The exchange coupling film comprises Ni _1-X Fe _X (0 <
The magnetoresistive effect element according to claim 1, which is an alloy film of x ≦ 0.3). 5. The film thickness of the exchange coupling film is 3 nm or more,
The magnetoresistive effect element according to any one of claims 1 to 4, which is in a range of 12 nm or less. 6. A film thickness t of the exchange coupling film and a saturation magnetic field Bs.
The magnetoresistive effect element according to any one of claims 1 to 5, wherein the product of is in the range of 3 (T · nm) ≦ Bs · t ≦ 12 (T · nm). 7. A magnetic head comprising the magnetoresistive effect element according to claim 1. Description: 8. A magnetic-magnetic recording apparatus comprising the magnetic head according to claim 7.