JPH09305925A - Magnetoresistance effect element and magnetoresistance effect type magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a magneto resistance effect film to be a single magnetic domain and suppress the generation of Barkhausen noises even when a magnetism-sensitive part has a wide width, buy layering an antiferromagnetic film at a part of the magnetism-sensitive part. SOLUTION: A magneto resistance effect element 1 of an SAL bias method is comprised of an SAL film 2, a non-magnetic spacer film 3, a magneto resistance effect film 4 and an antiferromagnetic film 5 layered sequentially. A magnetism-sensitive part sensing a magnetic field among the magneto resistance effect film 4 is a part located between electrodes 6 and 7. The antiferromagnetic film 5 is formed to be in touch with the whole face of the magnetism-sensitive part. Accordingly, the films 4 and 5 are exchange-coupled all over the face of the magnetism-sensitive part, and a magnetic domain of the film 4 is rendered more stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel magnetoresistive effect element in which Barkhausen noise caused by the magnetic domain is reduced by stabilizing the magnetic domain of the magnetoresistive effect film. The present invention also relates to a novel magnetoresistive effect magnetic head using such a magnetoresistive effect element.

[0002]

2. Description of the Related Art A magnetoresistive effect element is an element using a magnetoresistive effect film whose resistance value changes depending on the magnitude of a magnetic field, and is used as a magnetic field detecting element in a magnetic head, a geomagnetic direction sensor, or the like. ing.

The magnetoresistive effect element basically comprises a magnetoresistive effect film formed in a substantially strip shape and a pair of electrodes connected to the magnetoresistive effect film. Then, when detecting the magnetic field, a sense current is supplied to the magnetoresistive effect film through the pair of electrodes, thereby detecting the resistance change of the magnetoresistive effect film. At this time, the resistance value of the magnetoresistive effect film changes depending on the magnitude of the magnetic field applied to the magnetoresistive effect film. Therefore, by detecting the resistance change of the magnetoresistive effect film, the magnitude of the magnetic field applied to the magnetoresistive effect film can be detected.

In such a magnetoresistive effect element, it is the part of the magnetoresistive effect film located between the electrodes that functions as the magnetic sensing part for sensing the magnetic field. The portion of the magnetoresistive film that is in contact with the electrodes and the portion outside the pair of electrodes hardly contributes to the detection of the magnetic field.

In the magnetoresistive effect element, when the magnetic domain in the magnetoresistive effect film is unstable, the reproduction output becomes discontinuous due to the sudden movement of the domain wall, and so-called Barkhausen noise occurs. Therefore, in the magnetoresistive effect element, it is a major problem to make the magnetoresistive film a single magnetic domain to stabilize the magnetic domain.

Therefore, a method using a hard magnetic film or an antiferromagnetic film has been proposed as a method for stabilizing the magnetic domains of the magnetoresistive film. Specifically, a hard magnetic film is arranged on a portion other than the magnetically sensitive portion of the magnetoresistive effect element, that is, a lower layer of an electrode portion connected to the magnetoresistive effect film, a portion outside the pair of electrodes, and the like. A method of stabilizing the magnetic domains of the magnetoresistive film by a bias magnetic field from the hard magnetic film has been proposed.
Alternatively, an antiferromagnetic film is provided in a portion other than the magnetic sensitive portion of the magnetoresistive effect element, that is, in a lower layer of an electrode portion connected to the magnetoresistive effect film, a portion outside a pair of electrodes, or the like. A method for stabilizing the magnetic domains of the magnetoresistive film by exchange coupling between the ferromagnetic film and the magnetoresistive film has been proposed.

As described above, when the hard magnetic film or the antiferromagnetic film is used, the magnetization direction of the magnetoresistive film near the electrode is changed by the bias magnetic field from the hard magnetic film or the exchange coupling with the antiferromagnetic film. Align in one direction. Then, by aligning the magnetization directions of the magnetoresistive film near the electrodes in one direction,
The magnetization direction of the portion between the electrodes, that is, the portion that becomes the magnetic sensitive portion is also aligned in one direction, the entire magnetoresistive effect film becomes a single magnetic domain, and the magnetic domain of the magnetoresistive effect film becomes stable.

[0008]

However, when the magnetoresistive film is made to have a single magnetic domain as described above, the distance between the electrodes, that is, the width of the magnetic sensitive portion must be sufficiently narrow. If the width of the magnetic sensitive portion is wide, even if the magnetization directions of the magnetoresistive film near the electrodes are aligned in one direction, the influence does not contribute to the entire magnetic sensitive portion, and the magnetic domain is formed in the magnetic sensitive portion. Will occur. When a magnetic domain is generated in the magnetic sensitive section, Barkhausen noise is generated.

Therefore, the conventional method for magnetic domain stabilization is
Although it was effective for the magnetoresistive effect element having a narrow magnetic sensitive portion, it was not possible to obtain a sufficient effect for the magnetoresistive effect element having a wide magnetic sensitive portion.

By the way, in a magnetoresistive effect magnetic head which is a magnetic head using a magnetoresistive effect element, the track width thereof corresponds to the width of the magnetic sensing portion of the magnetoresistive effect element used. Therefore, in the magnetoresistive effect type magnetic head having a wide track width, the width of the magnetic sensitive section of the magnetoresistive effect element becomes wide, and it is difficult to stabilize the magnetic domain of the magnetic sensitive section of the magnetoresistive effect element. . That is, particularly in a magnetoresistive effect magnetic head having a wide track width, reduction of Barkhausen noise due to magnetic domains generated in the magnetically sensitive portion is a major issue.

The present invention has been proposed in view of such a conventional situation, and even if the width of the magnetic sensing portion is wide, the magnetoresistive effect film can be formed into a single magnetic domain, and the Barkhausen noise can be reduced. It is an object of the present invention to provide a magnetoresistive effect element capable of suppressing the generation. Another object of the present invention is to provide a magnetoresistive effect magnetic head capable of suppressing the occurrence of Barkhausen noise even if the track width is wide.

[0012]

A magnetoresistive effect element according to the present invention completed in order to achieve the above-mentioned object is characterized in that an antiferromagnetic film is laminated on at least a part of a magnetic sensing part. And Here, it is preferable that the antiferromagnetic film has a larger specific resistance than that of the magnetic sensitive portion, and that the antiferromagnetic film is disposed so as to contact substantially the entire surface of the magnetic sensitive portion.

In the magnetoresistive effect element according to the present invention, since the antiferromagnetic film is laminated on the magnetic sensitive portion, the magnetic sensitive portion and the antiferromagnetic film are exchange-coupled with each other, whereby the magnetization of the magnetic sensitive portion is magnetized. The directions are aligned in one direction, and the magnetic sensitive section is made into a single magnetic domain.

Further, when the specific resistance of the antiferromagnetic film is made larger than the specific resistance of the magnetic sensitive section, even if the antiferromagnetic film is laminated on the magnetic sensitive section, the sense current supplied to the magnetoresistive effect element. Flows mainly in the magnetically sensitive portion, and does not flow so much in the antiferromagnetic film. Therefore, by making the specific resistance of the antiferromagnetic film larger than the specific resistance of the magnetic sensing section, it is possible to prevent the output from being lowered due to the sense current flowing through the antiferromagnetic film.

On the other hand, a magnetoresistive effect type magnetic head according to the present invention is a magnetoresistive effect type magnetic head for detecting a magnetic signal by a magnetoresistive effect element, and at least a part of a magnetic sensitive portion of the magnetoresistive effect element. Is characterized in that an antiferromagnetic film is laminated thereon. Here, it is preferable that the antiferromagnetic film has a larger specific resistance than that of the magnetic sensitive portion, and that the antiferromagnetic film is disposed so as to contact substantially the entire surface of the magnetic sensitive portion.

In the magnetoresistive effect type magnetic head according to the present invention, since the antiferromagnetic film is laminated on the magnetic sensitive part, the magnetic sensitive part of the magnetoresistive effect element and the antiferromagnetic film are exchange-coupled with each other. As a result, the magnetization directions of the magnetic sensitive section are aligned in one direction, and the magnetic sensitive section is made into a single magnetic domain.

Further, when the specific resistance of the antiferromagnetic film is made larger than the specific resistance of the magnetic sensitive section, even if the antiferromagnetic film is laminated on the magnetic sensitive section, the sense current supplied to the magnetoresistive effect element. Flows mainly in the magnetically sensitive portion, and does not flow so much in the antiferromagnetic film. Therefore, by making the specific resistance of the antiferromagnetic film larger than the specific resistance of the magnetic sensing section, it is possible to prevent the output from being lowered due to the sense current flowing through the antiferromagnetic film.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the following examples, and it goes without saying that the shape, material, and the like can be arbitrarily changed without departing from the gist of the present invention.

The magnetoresistive element according to the present embodiment is
A SAL (Soft Adjacent Layer) bias type magnetoresistive effect element 1 as shown in FIG.
And a non-magnetic spacer film 3, a magnetoresistive effect film 4, and an antiferromagnetic film 5 are laminated. And
This laminated film is formed in a substantially strip shape, and is provided with a pair of electrodes 6 and 7 formed in contact with the magnetoresistive effect film 4 near both ends in the longitudinal direction thereof.

The SAL film 2 is for applying a bias magnetic field to the magnetoresistive film 4, and is made of a soft magnetic material. The SAL film 2 receives a magnetic field generated by a sense current flowing in the magnetoresistive effect film 4, and applies a bias magnetic field to the magnetoresistive effect film 4 in a form of amplifying the magnetic field.

The non-magnetic spacer film 3 formed on the SAL film 2 is for electrically and magnetically insulating the SAL film 2 and the magnetoresistive effect film 4, and has a specific resistance of the magnetoresistive effect film. It is made of a non-magnetic material larger than 4.

The magnetoresistive film 4 formed on the non-magnetic spacer 3 is made of a magnetic material exhibiting an anisotropic magnetoresistive effect, and its resistance value changes depending on the magnitude of the magnetic field. A pair of electrodes 6 and 7 are connected to the magnetoresistive film 4, and a sense current is supplied through the pair of electrodes 6 and 7 when detecting a magnetic field. The portion of the magnetoresistive film 4 that functions as a magnetic sensing unit that senses a magnetic field is the portion located between the electrodes 6 and 7.

The antiferromagnetic film 5 formed on the magnetoresistive effect film 4 is for exchange coupling with the magnetoresistive effect film 4 to stabilize the magnetic domain of the magnetoresistive effect film 4.
It is made of an antiferromagnetic material such as NiCoO, CoO, NiMn or FeMn.

Here, the antiferromagnetic film 5 includes electrodes 6 and 7.
The entire surface of the magnetoresistive effect film 4 located between and,
It is formed so as to come into contact with the entire surface of the magnetic sensing part. By thus forming the antiferromagnetic film 5 so as to contact the entire surface of the magnetically sensitive portion, the magnetoresistive film 4 and the antiferromagnetic film 5 are exchange-coupled to each other over the entire surface of the magnetically sensitive portion. The magnetic domains of the effect film 4 become more stable. However, in the present invention, it is not essential to form the antiferromagnetic film 5 over the entire surface of the magnetic sensitive portion, and the antiferromagnetic film 5 is arranged so as to contact at least a part of the magnetic sensitive portion. It goes without saying that the effects of the invention can be obtained.

Further, the antiferromagnetic film 5 is preferably made of a material having a higher specific resistance than the magnetoresistive film 4.
Further, it is more preferably made of an insulating material. By forming the antiferromagnetic film 5 from a material having a high specific resistance, more preferably an insulating material, a sense current mainly flows through the magnetoresistive film 4 when a magnetic field is detected, and Almost no current flows, and a higher reproduction output can be obtained.

In the magnetoresistive effect element having the above-mentioned structure, the magnetization direction of the magnetoresistive effect film 4 is oriented in the longitudinal direction due to the effects of magnetic anisotropy and shape anisotropy.
Moreover, in this magnetoresistive effect element, the magnetization direction of the magnetoresistive effect film 4 is aligned in one direction by the exchange coupling between the magnetoresistive effect film 4 and the antiferromagnetic film 5 even when there is no external magnetic field. The magnetoresistive film 4 as a whole forms a single domain structure having a specific polarity.

An example of the magnetization curve of such a magnetoresistive effect element 1 is shown in FIG. In FIG. 2, the magnetization curve J1 is
A magnetization curve when a magnetic field is applied to the magnetoresistive film 4 in the easy axis direction is shown, and a magnetization curve J2 shows a magnetic curve when a magnetic field is applied to the magnetoresistive film 4 in the hard axis direction. ing.

As shown in FIG. 2, the magnetoresistive effect element 1 is magnetized by the exchange coupling magnetic field Hex due to the exchange coupling between the magnetoresistive effect film 4 and the antiferromagnetic film 5 in the easy magnetization axis direction. The curve J1 is shifted, and the magnetization is saturated even when there is no external magnetic field. This is because even if there is no external magnetic field, the magnetization direction of the magnetoresistive effect film 4 is aligned in one direction due to the exchange coupling between the magnetoresistive effect film 4 and the antiferromagnetic film 5, and the magnetoresistive effect film 4 as a whole. Indicates that it has a single domain structure with a specific polarity.

Next, the magnetoresistive effect element 1 as described above
An example of the manufacturing method will be described.

When the magnetoresistive effect element 1 is manufactured,
First, the SAL film 2, the nonmagnetic spacer film 3, the magnetoresistive film 4, and the antiferromagnetic film 5 are sequentially formed on the substrate by the sputtering method.

Here, the magnetoresistive film 4 and the antiferromagnetic film 5
In order to obtain a stable exchange coupling, it is desirable that the interface between and is continuously formed without breaking the vacuum. Inevitably, when the interface between the magnetoresistive film 4 and the antiferromagnetic film 5 is exposed to the atmosphere, the surface of the magnetoresistive film 4 is subjected to a treatment such as etching to expose the surface of the magnetoresistive film 4. To remove the oxide layer generated in the.

Next, the SAL film 2, the non-magnetic spacer film 3, the magnetoresistive film 4 and the antiferromagnetic film 5 formed on the substrate.
The laminated film made of is formed into a predetermined shape by etching, and then a pair of electrodes 6 and 7 is formed so as to be connected to the magnetoresistive effect film 4. When forming the electrodes 6 and 7, first, a part of the antiferromagnetic film 5 is removed by photolithography and ion milling to expose two portions of the magnetoresistive effect film 4. Next, the electrodes 6 and 7 are embedded so as to directly contact the exposed magnetoresistive film 4.

Through the above steps, the SAL film 2, the non-magnetic spacer film 3, the magnetoresistive effect film 4 and the antiferromagnetic film 5 are formed so as to be connected to the magnetoresistive effect film 4. The magnetoresistive effect element 1 including the pair of electrodes 6 and 7 is completed.

In the above description, the SAL film 2, the nonmagnetic spacer film 3, the magnetoresistive effect film 4, and the antiferromagnetic film 5 are formed in this order, but the reverse order, that is, the antiferromagnetic film 5 is used. The magnetoresistive film 4, the nonmagnetic spacer film 3, and the SAL film 2 may be formed in this order. At this time, the electrodes 6 and 7 are formed by removing a part of the SAL film 2 and the nonmagnetic spacer film 3 by photolithography and ion milling to expose two portions of the magnetoresistive effect film 4 and exposing the exposed portions. The electrodes 6 and 7 may be embedded so as to be in direct contact with the magnetoresistive film 4.

Next, the magnetoresistive effect element 1 as described above
The following describes the results of actually manufacturing the device and examining its characteristics.

Here, the material of the magnetoresistive film 4 is N
i81% and Fe19% permalloy was used, and NiO was used as the material of the antiferromagnetic film 5. Then, the relationship between the magnitude of the exchange coupling magnetic field Hex, the coercive force Hc, and the anisotropic magnetic field Hk in the easy axis direction and the film thickness of the magnetoresistive effect film 4 was examined. The results are shown in FIG.

As shown in FIG. 3, the exchange coupling magnetic field Hex and the anisotropic magnetic field Hk are larger as the magnetoresistive effect film 4 is thinner. Further, when the film thickness of the magnetoresistive effect film 4 is 150 nm or less, the exchange coupling magnetic field Hex is larger than the coercive force Hc in the easy axis direction at any film thickness.

As can be seen from the above-mentioned magnetization curve J1 of FIG. 2, if the exchange coupling magnetic field Hex is larger than the coercive force Hc in the direction of the easy axis of magnetization, the magnetoresistive film 4 of the magnetoresistive effect film 4 will have no external magnetic field. The magnetization is saturated, and the magnetoresistive effect film 4 becomes a single magnetic domain. Therefore, it can be seen from the results shown in FIG. 3 that when the film thickness of the magnetoresistive effect film 4 is 150 nm or less, the magnetoresistive effect film 4 becomes a single domain at any film thickness. When the magnetoresistive effect film 4 is formed into a single magnetic domain as described above, the domain wall in the magnetoresistive effect film 4 does not move, so that Barkhausen noise, which is a variation in reproduction output due to the domain wall motion, is suppressed. To be done.

Here, although Permalloy was used as the material of the magnetoresistive effect film 4 and NiO was used as the material of the antiferromagnetic film 5, in the present invention, the magnetoresistive effect film 4 and the antiferromagnetic film 5 are used. The combination of is not limited to this. That is, according to the present invention, the magnetoresistive effect film 4 and the antiferromagnetic film 5 are exchange-coupled with each other to make the magnetoresistive effect film 4 into a single magnetic domain, and the magnetic characteristics as shown in FIG. 3 are obtained. Any combination of materials, that is, a combination of materials in which the exchange coupling magnetic field Hex is sufficiently larger than the coercive force Hc can be widely used.

By the way, the magnetoresistive effect element 1 is desired to have not only less noise but also excellent magnetic field detection sensitivity and high reproduction output. In general, the magnetic field detection sensitivity of the magnetoresistive effect element 1 is determined by the slope a of the resistance change rate curve MR as shown in FIG. The slope a of the resistance change rate curve MR is the saturation magnetic field H of the magnetoresistive effect film 4.
The smaller s, the steeper it becomes. Therefore, in order to improve the magnetic field detection sensitivity of the magnetoresistive effect element 1, it is necessary to reduce the saturation magnetic field Hs of the magnetoresistive effect film 4.

The saturation magnetic field Hs substantially matches the sum of the demagnetizing field Hd generated in the magnetoresistive film 4 and the anisotropic magnetic field Hk. Here, the demagnetizing field Hd is generated in the minor axis direction of the magnetoresistive effect film 4 depending on the shape of the magnetoresistive effect film 4 when the magnetoresistive effect film 4 is patterned into a substantially strip shape.

Then, as described above, the saturation magnetic field Hs
Is substantially equal to the sum of the demagnetizing field Hd generated in the magnetoresistive effect film 4 and the anisotropic magnetic field Hk. Therefore, in order to improve the magnetic field detection sensitivity of the magnetoresistive effect element 1, the magnitude of the anisotropic magnetic field Hk is required. Is desirable to be as small as possible.

Specifically, for example, according to the experimental data shown in FIG. 3, when the film thickness of the magnetoresistive effect film 4 is about 50 nm, the anisotropic magnetic field Hk is about 1.6 kA / m. . Here, the original anisotropic magnetic field Hex of the magnetoresistive film 4 made of permalloy is about 0.8 kA / m, and the amount increased by exchange coupling with the antiferromagnetic film 5 is:
It is about 0.8 kA / m.

On the other hand, the demagnetizing field H generated in the magnetoresistive film 4
The magnitude of d is approximately represented by the following equation (1), assuming that the length of the magnetoresistive effect film 4 in the major axis direction is infinite.

Hd = 4 × π × Ms × d / h (1) Here, h is the length of the magnetoresistive effect film 4 in the short axis direction, and d is the magnetoresistive effect film 4. It is the film thickness, and Ms is the saturation magnetization intensity of the magnetoresistive effect film 4.

Then, for example, when the magnetoresistive effect element 1 is applied to a magnetic head, the magnetic flux penetrating from the magnetic recording medium to the magnetic sensitive portion of the magnetoresistive effect element 1 is usually about 4 μm from the magnetic recording medium facing surface. Penetrates to the depth of. Therefore, here, the length d of the magnetoresistive effect film 4 in the minor axis direction is set to about 4 μm. At this time, the demagnetizing field Hd of the magnetoresistive effect film 4 is about 10 kA / m from the above formula (1).

As described above, since the anisotropic magnetic field Hk of the magnetoresistive effect film 4 is about 1.6 kA / m, the saturation magnetic field Hs represented by the sum of the anisotropic magnetic field Hk and the demagnetizing field Hd.
Is about 11.6 kA / m. At this time, the increase amount of the saturation magnetic field Hs due to the exchange coupling with the antiferromagnetic film 5 is about 0.8.
Since it is kA / m, exchange coupling with the antiferromagnetic film 5 reduces the output by about 7%.

On the other hand, according to the experimental data shown in FIG.
When the film thickness of the magnetoresistive effect film 4 is about 50 nm, the exchange coupling magnetic field Hex is sufficiently larger than the coercive force Hc. Therefore, the magnetoresistive effect film 4 has a single magnetic domain, and a stable output in which generation of Barkhausen noise is suppressed can be obtained from the magnetoresistive effect element 1.

As described above, in the magnetoresistive effect element 1 according to the present embodiment in which the magnetic domain of the magnetoresistive effect film 4 is stabilized by the exchange coupling with the antiferromagnetic film 5, the output is slightly reduced. The generation of magnetic domains is suppressed, and stable output is obtained. Moreover, the decrease in output caused by the exchange coupling with the antiferromagnetic film 5 is not so large, and is about 7% in the above example. The decrease in output to this extent is within an allowable range in normal use, and the merit of Barkhausen noise reduction by stabilizing magnetic domains is greater.

Conventionally, by exchange coupling with an antiferromagnetic film,
When stabilizing the magnetic domains of the magnetoresistive effect film, the antiferromagnetic film is arranged in a portion other than the magnetic sensitive portion of the magnetoresistive effect element.
This is because it has been considered that when an antiferromagnetic film is arranged in the magnetic sensitive portion of the magnetoresistive effect element, the magnetic field generated by exchange coupling with the antiferromagnetic film significantly reduces the magnetic field detection sensitivity.

However, as can be seen from the above description, even if the antiferromagnetic film 5 is arranged so as to contact the magnetically sensitive portion by appropriately setting the film thickness of the magnetoresistive effect film 4 and the like,
The decrease in output can be suppressed to a sufficiently low level. Moreover,
When the antiferromagnetic film 5 is formed on the entire magnetic sensitive portion of the magnetoresistive film 4, the antiferromagnetic film 5 is formed on the entire magnetic sensitive portion.
Since exchange coupling occurs with the magnetic domain, the magnetic domain is stabilized over the entire surface of the magnetic sensing part. Therefore, according to the present invention, it is possible to stabilize the magnetic sensing part, no matter how wide the magnetic sensitive part is.

However, when the width of the magnetic sensitive portion, that is, the length of the magnetic sensitive portion in the major axis direction is about the same as the length in the minor axis direction, the demagnetizing field Hd becomes small, and therefore the antiferromagnetic property is obtained. It is also considered that the influence of the increase of the anisotropic magnetic field Hk due to the exchange coupling with the film 5 becomes relatively large, and as a result, the output is greatly reduced. Therefore, the present invention is more effective when the width of the magnetic sensitive portion is longer, and in consideration of the practical value of the magnetic sensitive portion in the short axis direction, specifically, the present invention has a length of the magnetic sensitive portion of 5 μ.
It is particularly effective when m or more.

Next, the magnetoresistive effect element 1 as described above
A magnetoresistive effect magnetic head using is explained.

This magnetoresistive effect magnetic head is a magnetoresistive effect magnetic head for detecting a magnetic signal by the above-mentioned magnetoresistive effect element, and as shown in FIG. Is a magnetoresistive effect element 11, insulating layers 12 and 13 disposed above and below the magnetoresistive effect element 11, and the magnetoresistive effect element 11 is an insulating layer 12, 1.
And a pair of magnetic shields 14 and 15 sandwiching the magnetic shields 3 and 3.

In the magnetoresistive effect magnetic head 10, the pair of magnetic shields 14 and 15 serve to magnetically shield the magnetoresistive effect element 11 from above and below, and are made of a magnetic material. In addition, the magnetic shields 14 and 15
And an insulating layer 12 disposed between the magnetoresistive effect element 11 and
Reference numeral 13 is the magnetic shields 14 and 15 and the magnetoresistive effect element 1.
To form a magnetic gap with
It is made of a non-magnetic insulating material.

The magnetoresistive effect element 11 sandwiched by the magnetic shields 14 and 15 via the insulating layers 12 and 13 has the same structure as the magnetoresistive effect element 1 described in the above embodiment. There is. That is, the magnetoresistive effect element 11 has a laminated film 11a in which a SAL film, a nonmagnetic spacer film, a magnetoresistive effect film, and an antiferromagnetic film are laminated.
And the electrode 11 provided in contact with the magnetoresistive film.
b. The magnetoresistive effect element 11 has a sense current supplied to the magnetoresistive effect film,
The magnetic field to be detected is arranged to be substantially vertical.
Here, the width of the magnetic sensitive portion of the magnetoresistive effect element 11 corresponds to the track width of the magnetoresistive effect magnetic head 10.

The magnetoresistive effect type magnetic head 1 as described above.
FIG. 6 shows how an information signal is reproduced from the magnetic recording medium by 0. Here, FIG. 6 is a diagram schematically showing how an information signal is reproduced by the magnetoresistive effect magnetic head 10. The main parts of the magnetoresistive effect magnetic head 10 are shown in FIG.
The magnetic recording medium 20 is illustrated.

As shown in FIG. 6, when reproducing an information signal from the magnetic recording medium 20, the magnetoresistive head 1 is used.
The recording medium facing surface of 0 is made to face the recording track of the magnetic recording medium 20, and a constant sense current is supplied to the magnetoresistive effect film 11a through the pair of electrodes 11b to detect the voltage change. At this time, the resistance value of the magneto-resistive effect element 11 changes due to the change in the direction of the magnetic field recorded on the magnetic recording medium 20. Therefore, by detecting this resistance change as a voltage change, the information signal from the magnetic recording medium 20 is reproduced.

In this magnetoresistive effect type magnetic head, the magnetoresistive effect element 10 similar to the magnetoresistive effect element 1 described in the above embodiment is used.
Barkhausen noise is small and stable playback output can be obtained.

In this example, the magnetoresistive effect element 10 is arranged so that the sense current supplied to the magnetoresistive effect element 10 and the magnetic field to be detected are substantially perpendicular to each other. Although the head is taken as an example, a magnetoresistive effect type of the type in which the magnetoresistive effect element 10 is arranged such that the sense current supplied to the magnetoresistive effect element 10 and the magnetic field to be detected are substantially parallel to each other. The present invention can also be applied to a magnetic head.

[0061]

As is apparent from the above description, in the magnetoresistive effect element according to the present invention, since the magnetic sensitive portion and the antiferromagnetic film are exchange-coupled, even if the width of the magnetic sensitive portion is wide, The magnetization directions of the magnetic parts are aligned in one direction. That is, according to the present invention, it is possible to realize a stable single domain structure having no domain wall even if the width of the magnetic sensing portion is wide. Therefore, according to the present invention, it is possible to provide a magnetoresistive effect element capable of suppressing the generation of Barkhausen noise, which is a variation in reproduction output due to the movement of the domain wall, and capable of detecting a magnetic field with high sensitivity. .

Similarly, in the magnetoresistive effect type magnetic head according to the present invention using such a magnetoresistive effect element, even if the width of the magnetic sensitive portion of the magnetoresistive effect element used is wide, Barkhausen Generation of noise is suppressed. Therefore, according to the present invention, it is possible to provide a magnetoresistive effect magnetic head capable of suppressing the occurrence of Barkhausen noise and detecting a magnetic signal from a recording medium with high sensitivity even if the track width is wide. Can be done.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a magnetoresistive effect element to which the present invention is applied.

FIG. 2 is a diagram showing an example of a magnetization curve of a magnetoresistive effect element to which the present invention is applied.

FIG. 3 shows the thickness of the magnetoresistive film and the exchange coupling magnetic field He.
It is a figure which shows the result of having measured the relationship with x, coercive force Hc, or anisotropic magnetic field Hk.

FIG. 4 is a diagram showing an example of a resistance change rate curve in a biased state.

FIG. 5 is a sectional view showing an example of a magnetoresistive effect magnetic head to which the present invention is applied.

FIG. 6 is a schematic diagram showing how an information signal is reproduced by a magnetoresistive effect magnetic head to which the present invention is applied.

[Explanation of symbols]

1 magnetoresistive effect element, 2 SAL film, 3 non-magnetic spacer film, 4 magnetoresistive effect film, 5 antiferromagnetic film, 6, 7 electrode

Claims (9)

[Claims] 1. A magnetoresistive effect element comprising an antiferromagnetic film laminated on at least a part of a magnetically sensitive portion. 2. The magnetoresistive effect element according to claim 1, wherein the antiferromagnetic film has a larger specific resistance than the magnetic sensitive section. 3. The antiferromagnetic film is arranged so as to contact substantially the entire surface of the magnetic sensing part.
The magnetoresistive effect element as described in the above. 4. The magnetoresistive effect element according to claim 1, wherein the length of the magnetic sensing portion is 5 μm or more. 5. A magnetoresistive effect magnetic head for detecting a magnetic signal by a magnetoresistive effect element, wherein an antiferromagnetic film is laminated on at least a part of a magnetic sensitive portion of the magnetoresistive effect element. Magnetoresistive effect magnetic head. 6. The magnetoresistive head according to claim 5, wherein the antiferromagnetic film has a larger specific resistance than the magnetic sensitive section. 7. The antiferromagnetic film is arranged so as to be in contact with substantially the entire surface of the magnetically sensitive portion.
The magnetoresistive effect type magnetic head as described in the above. 8. The magnetoresistive effect magnetic head according to claim 5, wherein the length of the magnetic sensing portion is 5 μm or more. 9. The magnetoresistive effect element is arranged such that a sense current supplied to the magnetoresistive effect element and a magnetic field to be detected are substantially perpendicular to each other. Magnetoresistive effect magnetic head.