JP2699959B2 - Magnetoresistance effect element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-resistance effect element, and more particularly, to a magneto-resistance effect element for reading a magnetic field intensity as a signal in a magnetic medium or the like.
In particular, the present invention provides a magnetoresistive head using an artificial lattice magnetoresistive film in which the rate of change of resistance is large at a small external magnetic field and two or more magnetic layers are stacked via a nonmagnetic layer,
A magnetoresistive sensor comprising means for sensing (detecting) the rate of change in resistance of the magnetoresistive element as a change in the detected magnetic field
(Detection) system.

[0002]

2. Description of the Related Art In recent years, higher sensitivity of magnetic sensors and higher density in magnetic recording have been promoted.
The development of a magnetoresistive magnetic sensor (hereinafter referred to as "MR sensor") and a magnetoresistive magnetic head (hereinafter referred to as "MR head") have been actively promoted.

Both the MR sensor and the MR head read an external magnetic field signal by a change in resistance of a reading sensor portion made of a magnetic material. The MR sensor and the MR head have a relative speed with respect to a recording medium. Does not depend on the reproduction output, the MR sensor has a characteristic that high sensitivity can be obtained, and the MR head has a characteristic that a high output can be obtained even in high-density magnetic recording.

A magnetoresistive element having at least two magnetic thin films stacked with a nonmagnetic thin layer interposed therebetween, wherein magnetic thin layers having different coercive forces are stacked with the nonmagnetic thin film interposed therebetween. A magnetoresistive element has been proposed in, for example, Japanese Patent Application Laid-Open No. 4-218982.

[0005]

The conventional MR "has two magnetic layers stacked with a non-magnetic layer interposed therebetween, and is characterized in that the two magnetic layers have different coercive forces" In the element, the difference in coercive force between the respective magnetic layers is not so large. In the above-mentioned conventional MR element, since the difference in coercive force is not so large, for example, when the detection magnetic field is large, not only the magnetic layer having a small coercive force but also the magnetic layer having a large coercive force are inverted. However, there has been a problem that the rate of change in magnetoresistance thereafter becomes small or the polarity of the detection magnetic field is reversed.

As a means for solving the above problem, a method of arranging an FeMn antiferromagnetic layer in contact with one magnetic layer and adding unidirectional anisotropy of exchange coupling to fix the magnetization of the magnetic layer. Has also been proposed. However, FeMn
Has a drawback that it is easy to corrode, and it is difficult to ensure reliability and long-term storage when processing a magnetoresistive element into a sensor.

The present invention has been made in view of the above problems and disadvantages, and the technical problem of the present invention is mainly to improve the output as compared with a conventional permalloy MR head. First, it is to provide a magnetoresistive element exhibiting a function and an effect of improving output and corrosion resistance in particular, and a method of manufacturing the same. Secondly, to provide a "yoke type or shield type MR head" using the magnetoresistive effect element. Thirdly, similarly, a "magnetoresistive sensing system""magnetic recording / reproducing". System ".

[0008]

According to the present invention, there is provided a magnetoresistive element having a structure in which magnetic layers having different coercive forces are laminated via a nonmagnetic thin film layer, and a first magnetic layer and an adjacent magnetic layer are adjacent to the first magnetic layer. Element comprising a second magnetic layer / non-magnetic layer / third magnetic layer provided as described above, or a first magnetic layer and the first magnetic layer
In a magnetoresistive element comprising a nonmagnetic layer / third magnetic layer provided adjacent to a magnetic layer, the first magnetic layer is made of CoCr, CoCrPt, CoCrTa, SmCo, NdFe or an alloy containing these as a main component. (Claims 1 and 2).

[0009] The magneto-resistance effect element may include:-the first magnetic layer is made of CoCr, CoCrPt or CoCrTa;
And using Cr as an underlayer of the first magnetic layer.
(Claim 3), wherein the second magnetic layer or the third magnetic layer is made of NiFe, NiFeC
o, FeCo, Co or an alloy containing these as main components (claims 4 and 5);-The nonmagnetic layer is made of Cu, Au, Ag or an alloy containing these as main components (claims) Items 6 to 8) are characterized.

[0010] The method of manufacturing a magnetoresistive element according to the present invention may be configured as follows.
And heat-treating in a temperature range of 150 to 250 ° C. ”(claim 9).

The MR head according to the present invention is characterized in that: the magnetoresistance effect element is used as a "yoke type MR head in which the MR element is recessed from the ABS surface";
0), The invention is characterized in that the magnetoresistance effect element is used in a "shielded MR head in which an MR element is sandwiched between soft magnetic layer shield films" (claim 11).

A magnetoresistive sensing system according to the present invention is a magnetoresistive sensing (detecting) system including means for sensing (detecting) the rate of change in resistance of the magnetoresistive element as a change in a detected magnetic field. 3. The method according to claim 1, wherein
A magnetoresistive sensor wherein at least one of the second magnetic layer and the third magnetic layer is formed of a material selected from a group consisting of NiFe, NiFeCo, FeCo, and Co; Means for flowing a current through the second magnetic layer, and means for sensing a change in the specific resistance of the magnetoresistive sensor, wherein the direction of the magnetization of the second magnetic layer according to the magnetic field to be detected is based on the rotation difference of the magnetization of the third magnetic layer. And having "
(Claim 12).

[0013] The magnetoresistive sensing system may be configured such that: the second magnetic layer is made of Co or NiFeCo, and the third magnetic layer is made of NiFe or NiFeCo. The layers are Cu, Au, Ag, alloys based on these,
It is characterized by being formed of a material selected from a group consisting of a mixture thereof (claim 14).

The magnetic recording / reproducing system according to the present invention comprises:
"A magnetic recording medium having a plurality of tracks for recording data, and a conversion device for converting a magnetic field intensity into an electric intensity, wherein a relative movement between the magnetic recording medium and the conversion device is performed. First, second and third layers of ferromagnetic material which are maintained in close proximity to said magnetic recording medium and are separated by a layer of non-magnetic metal material, said layers being perpendicular to said magnetic recording medium. The second and third layers of a ferromagnetic material, and CoCr, CoCrPt, CoCrTa, SmCo,
A magnetic transducer comprising a first magnetic layer made of NdFe or an alloy containing these as a main component; and a magnetic transducer coupled to the magnetic transducer for moving the magnetic transducer to a selected track of the magnetic recording medium. Actuator means and detection means connected to the magnetic transducer for detecting a change in resistance in the magnetic transducer due to a magnetic field produced by a magnetic domain recorded on the recording medium. (Claim 15).

[0015] The magnetic recording / reproducing system may include: a capping layer having a resistance sensor attached on the third magnetic layer; and a capping layer for connecting the magnetic transducer to the detecting means. And a lead wire means attached on the layer (claim 16).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the magnetoresistive effect element according to the present invention, as described above, CoCr, CoCrP
It is characterized by using t, CoCrTa, SmCo, NdFe or an alloy containing these as a main component.
Those having the following composition are preferred.

In the CoCr layer, Cr: 6 to 20%, balance: Co and CoCr are the main components. In the CoCrPt layer, Cr: 0 to 20%, Pt: 0 to 30%, balance: Co
And CoCrPt as the main component. ・ In the CoCrTa layer, Cr: 6 to 20%, Ta: 0 to 8%, balance: Co
And SmCo in the SmCo layer, the balance being an alloy containing Co and SmCo as the main component.-In the NdFe layer, Nd: 0 to 50%, the balance. : An alloy containing Fe and NdFe as main components is preferable. In the present invention,
It is not limited only to the above composition.

The upper limit of the thickness of each magnetic thin film is 300 angstroms. On the other hand, the lower limit of the thickness of each magnetic thin film is not particularly limited in the present invention. However, if the thickness is 4 Å or less, the Curie point becomes lower than room temperature and the practicability is lost. When the thickness of the magnetic thin film is 4 Å or more, it is easy to keep the film thickness uniform, and the film thickness becomes good. Also, the magnitude of the saturation magnetization does not become too small. Although the effect does not decrease even if the film thickness is set to 200 Å or more, the effect does not increase with an increase in the film thickness, and the production of the film is wasteful and uneconomical.

In the magnetoresistive element according to the present invention,
The nonmagnetic layer is preferably made of Cu, Au, Ag or an alloy containing these as a main component, and the thickness of the nonmagnetic thin film is desirably 50 Å or less. In general, if the thickness exceeds 50 angstroms, the resistance is determined by the non-magnetic thin film, and the spin-dependent scattering effect becomes relatively small, resulting in a small magnetoresistance change rate. It is not preferable. On the other hand, if the thickness of the non-magnetic thin film is less than 4 Å, the magnetic interaction between the magnetic thin films becomes too large, and the occurrence of a magnetic direct contact state (pinhole) is inevitable. However, it is not preferable because the anti-parallel state of the magnetization directions of the two magnetic thin films hardly occurs.

[0020]

The magnetoresistive element according to the present invention has two magnetic layers stacked with a non-magnetic thin film layer interposed therebetween, and has a different coercive force between the two magnetic layers. In the device, one magnetic layer is made of CoCr, CoCrPt, CoCrTa,
This is due to a single-layer film or a multilayer film containing SmCo and NdFe. The magnetic layers of CoCr, CoCrPt,
CoCrTa, SmCo, and NdFe have a large coercive force of about 700 Oe or more in the in-plane direction when produced by sputtering or vapor deposition.

In addition, these CoCr, CoCrPt, CoCrTa, SmC
When a laminated film is formed in combination with soft magnetic materials such as Co, NiFe, and NiFeCo, o and NdFe easily cause ferromagnetic coupling with these materials, and as a result, the coercive force of the magnetic layer in contact with CoCrPt Can be increased. In addition, CoCrPt is FeFe used for the spin valve film.
Since the activation energy is much lower than that of Mn or the like, the material has remarkably excellent corrosion resistance. The same applies to CoCr, CoCrTa, SmCo, and NdFe.

[0022]

Next, an embodiment of the present invention will be described.
The present invention is not limited only to the following examples.

(Embodiment 1) A first embodiment (embodiment 1) of the present invention comprises a first magnetic layer (CoCrPt) and a non-magnetic layer (Cu) provided adjacent to the first magnetic layer. This is an example of a magnetoresistive element composed of a third magnetic layer (NiFe) and using “Cr” as an underlayer of the first magnetic layer “CoCrPt”. That is, the first embodiment
Is a magnetoresistive element made of "glass / Cr / CoCrPt / Cu / NiFe". In the first embodiment, “CoCrPt” of the first magnetic layer has a composition of “Co: 72%, Cr: 16%,
Pt: 12% ".

With respect to the magnetoresistance effect element of the first embodiment,
This will be described with reference to FIGS. First, FIG. 1 shows the MH loop in the in-plane direction of the glass / Cr (50 °) / CoCrPt (150 °) film.
FIG. As is apparent from FIG. 1, the reversal magnetic field of this film is around 1000 Oe.
It shows the characteristics of a Pt single layer film.

FIG. 2 shows that Cu (25) is formed on a glass / Cr / CoCrPt film.
FIG. 3 is a diagram showing an MH loop provided with a (Å) / NiFe (100 °) film. This is because Cu (25mm) / NiFe on glass / Cr / CoCrPt film
(100 °) was formed and its MH loop was measured. Note that M is standardized by the maximum value “Mmax” of M.

FIG. 2 shows that the MH loop is a two-step loop consisting of inversion near zero magnetic field and inversion near 1 kOe. The former (inversion near zero magnetic field) is due to the inversion of the NiFe layer, and the latter (inversion near 1 kOe) is due to the inversion of the CoCrPt layer. As is apparent from FIG. 2, it can be understood that in this multilayer film, a parallel-antiparallel transition of each magnetization of the NiFe layer and the CoCrPt layer is easily realized.

FIG. 3 is a diagram showing the relationship between the MR ratio and the thickness of the Cu layer (nonmagnetic layer). The MR ratio increased with an increase in the thickness of the Cu layer, showed a local maximum near 35 °, and then tended to decrease. The maximum value of the MR ratio was about 3% as is clear from FIG.

(Embodiment 2) The second embodiment (Embodiment 2) of the present invention comprises a first magnetic layer (CoCrPt) and a second magnetic layer (CoCrPt) provided adjacent to the first magnetic layer. ) / Nonmagnetic layer (Cu) / third magnetic layer (NiFe), and is an example of a magnetoresistive element using “Cr” as an underlayer of the first magnetic layer “CoCrPt”.
That is, the second embodiment is described as “glass / Cr / CoCrPt / Co / Cu / Ni
This is a magnetoresistive element made of “Fe”. In the second embodiment, “CoCrPt” of the first magnetic layer has a composition of “Co: 78%, Cr: 14%, Pt: 8%”.

With respect to the magnetoresistive element of the second embodiment,
This will be described with reference to FIGS. In Example 2, a glass / Cr / CoCrPt / Co (30 °) / Cu (35 °) / NiFe (100 °) film was prepared, and the MH loop of the film was measured. FIG. 4 shows the measurement results.

From FIG. 4, it is clear that the MH loop has an area around 0 Oe and an area around 8 Oe.
It has a two-step loop near 00 Oe. The former (around 0 Oe) is the inversion of the NiFe layer, and the latter (around 800 Oe)
This is the inversion of the CrPt / Co layer. Even in this multilayer film, NiFe
It can be understood that the parallel-antiparallel transition of each magnetization of the layer and the CoCrPt layer is easily realized.

FIG. 5 is a diagram showing a change in MR ratio when the thickness of the Co layer (second magnetic layer) is changed. The MR ratio is Co
Increases with increasing layer thickness, rapidly increases at 20-3020,
It showed a local maximum near Å and then decreased.
The maximum value of the MR ratio was about 4% as shown in FIG.

(Embodiment 3) A third embodiment (Embodiment 3) of the present invention comprises a first magnetic layer (SmCo) and a second magnetic layer (NiFe) provided adjacent to the first magnetic layer. This is an example of a magnetoresistive element composed of a non-magnetic layer (Cu) / third magnetic layer (NiFe).
That is, the third embodiment is “glass / SmCo / NiFe / Cu / NiFe”
Of the magnetoresistive effect element.

The "SmCo layer", which is the first magnetic layer, has a substrate
Heating was performed at 0 ° C., and sputtering was performed in a state where an applied magnetic field of about 1 kOe was applied to the surface of the substrate to form a film. When the MH loop in the in-plane direction of the SmCo film was measured, the reversal magnetic field was about 700 Oe. In addition, using this SmCo film, "Glass / SmCo (200mm) / NiFe (50mm) / Cu (25mm)
/ NiFe (50 °) artificial lattice ”was prepared and subjected to MR measurement. As a result, the rate of change in resistance was 4%. Similarly, “glass / NdFe (200 °) / NiFe (50 °) / Cu (25 °) / NiFe (50 °) artificial lattice” exhibited a 3.5% resistance change rate.

(Embodiment 4) In the fourth embodiment (Embodiment 4) of the present invention, the "method of manufacturing a magnetoresistance effect element" of the present invention is described.
It is an example for explaining. FIG. 6 is a graph showing the relationship between the MR ratio and the heat treatment temperature.
FIG. 7 is a diagram showing the relationship between the rate of change in resistance and the heat treatment temperature when heat treatment is performed on the substrate. Here, what is subjected to the heat treatment is the one produced by sputtering. The heat treatment time was one hour.

As shown in FIG. 6, the resistance change rate (MR ratio)
Shows a gradual increase with increasing heat treatment temperature, shows a maximum value (5% or more) around 210 ° C, and then gradually decreases.
It decreased sharply between 350 ℃ and 400 ℃. As is clear from FIG. 6, the MR of 5% or more is obtained when the heat treatment temperature is between 150 and 250 ° C.
Since the ratio was obtained, it can be understood that this range is appropriate as the heat treatment temperature in the “method of manufacturing a magnetoresistance effect element” of the present invention. The heat treatment temperature is 0 ° C., that is, the MR ratio is high even without heat treatment.

In the fourth embodiment, the medium of the second embodiment is used
The heat treatment was performed on the sheet, but the same was true when the medium of Example 1 was heat-treated on the sheet.

(Embodiment 5) A fifth embodiment (Embodiment 5) of the present invention is a test example for explaining the "effect (lifetime) under a high temperature and high humidity environment" on the magnetoresistance effect element of the present invention. It is.

In the fifth embodiment, the "Cr / CoCrPt / Co / Cu / NiFe film", which is one embodiment of the present invention, is subjected to an "acceleration test using a high-temperature and high-humidity environment tester". : Life expectancy at 80% was estimated. The time required for the MR ratio to be halved is defined as "life", and the life is estimated. Further, for comparison, “Ta / NiFe / Cu / NiFe / FeMn
The same test as above was performed for the "spin valve film".
Its life was estimated.

As a result, the comparative example “Ta / NiFe / Cu /
The “NiFe / FeMn spin valve film” had a life of only 10 days, whereas the “Cr / CoCrPt /
The Co / Cu / NiFe film has a very long life of 21 years.

(Embodiment 6) The sixth embodiment (Embodiment 6) of the present invention is an embodiment relating to the "yoke type MR head" of the present invention.

Here, prior to the description of the sixth embodiment,
The structure of the "yoke type MR head" and its manufacturing method will be described with reference to FIG. 7 (conceptual diagram of the head) and FIG. 9 (manufacturing process diagram of the head). The yoke type MR head is
As shown in FIG. 7, a substrate 1, a lower yoke 2, an insulating material 3,
Underlayer 4, MR film 5, insulating layer 6, upper yoke 7, protective layer 8
It is composed of And this yoke type head is
As shown in FIG. 9, "substrate grooving → lower yoke film formation → heat treatment for improving lower yoke characteristics → pouring of insulating material → lapping → MR film formation → MR film heat treatment → MR film PR → electrode It is manufactured in the order of material deposition → electrode PR → insulating layer deposition → upper yoke deposition → upper yoke PR → protective layer deposition.

In the sixth embodiment, “(1); Cr / CoCrPt / Co / Cu / N” which is one embodiment of the “magnetoresistive element” of the present invention.
iFe film "and another embodiment"(2); Cr / CoCrTa /
The Co / Cu / NiFe film "is shown in FIG.
It is adapted to the MR element part of the head (for the manufacturing method, see FIG. 9 described above).

Using a head adapted to the above (1) and (2), contact recording was performed on a perpendicular recording medium having a structure of "glass / (Ta / NiFe) 5 / Cr / CoCrTa / C". However, in the example of (1), “1.2 mV”, and in the example of (2), “1.1 mV”.
V "was obtained. The recording mark length is 5μ.
m. For comparison, when longitudinal recording was performed using a floating MR head using permalloy as an MR element, the output was "0.25 mV".

Therefore, in the example (1) of the sixth embodiment, the output was improved 4.8 times (1.2 / 0.25) as compared with the comparative example, and in the example (2). , 4.4 times (1.1 /
This means that the output has been improved by 0.25).

(Embodiment 7) A seventh embodiment (Embodiment 7) of the present invention is an embodiment relating to a "shield type MR head" of the present invention.

Here, prior to the description of the seventh embodiment,
The structure of the "shield type MR head" will be described with reference to FIG. 8 (a schematic sectional view of the head). Shield type M
The R head is, as shown in FIG.
2, a lower gap 13, an MR film 14, an upper gap 15, an upper shield 16, and a protective film 17.

In the seventh embodiment, “Cr / CoCrPt / Co / Cu / NiFe” which is one embodiment of the “magnetoresistive element” of the present invention is described.
Of the shield type MR head shown in FIG.
Adapted to the element part. When a magnetic signal was reproduced using this MR head, 400 μV per 1 μm of track width was obtained.
/ Μm, and it was confirmed that about twice the output was obtained as compared with a shield type MR head using a conventional anisotropic MR film.

[0048]

As described above, according to the present invention,
CoCr, CoCrPt, CoCrTa, SmCo, and NdFe, which are magnetic layers, have a large coercive force of about 700 Oe or more in the in-plane direction when manufactured by sputtering. The difference in coercivity of the layers increases,
Even if the detection magnetic field is large, not only the layer having a small coercive force but also the layer having a large coercive force will not be reversed, and the polarity of the detected magnetic field will not be reversed. The effect of improving occurs. In addition, the conventional "FeMn
It is possible to provide an MR material that is dramatically superior in corrosion resistance as compared with a “spin valve film using an antiferromagnetic material”.

Further, in the yoke type head according to the present invention using the above MR material, the output is about 4 to 5 times better than that of the conventional head. -It has the effect of improving the output as compared with a Malloy-based MR head and improving the corrosion resistance as compared with a conventional FeMn-based spin valve film.

[Brief description of the drawings]

FIG. 1 In-plane MH of “Glass / Cr / CoCrPt film”
The figure which shows a loop.

Fig. 2 "Cu / NiFe film" on "Glass / Cr / CoCrPt film"
The figure which shows the MH loop of FIG.

FIG. 3 is a diagram showing a relationship between an MR ratio and a Cu layer thickness.

[Fig. 4] M of "glass / Cr / CoCrPt / Co / Cu / NiFe film"
The figure which shows -H loop.

FIG. 5 is a diagram showing a relationship between an MR ratio and a Co layer thickness.

FIG. 6 is a diagram showing a relationship between an MR ratio and a heat treatment temperature.

FIG. 7 is a conceptual diagram of a yoke type MR head.

FIG. 8 is a conceptual diagram of a shield type MR head.

FIG. 9 is a diagram showing a manufacturing process of the yoke type MR head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Lower yoke 3 Insulating material 4 Underlayer 5 MR film 6 Insulating layer 7 Upper yoke 8 Protective layer 11 Substrate 12 Lower shield 13 Lower gap 14 MR film 15 Upper gap 16 Upper shield 17 Protection film

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Kunihiko Ishihara, Inventor, NEC Corporation 7-1, Shiba 5-chome, Minato-ku, Tokyo (56) References JP-A-8-279118 (JP, A)

Claims (16)

(57) [Claims] A magnetic layer having a different coercive force is laminated via a non-magnetic thin film layer, and a first magnetic layer and a second magnetic layer / non-magnetic layer / second magnetic layer provided adjacent to the first magnetic layer. A magnetoresistive element comprising three magnetic layers, or a magnetoresistive element comprising a first magnetic layer and a nonmagnetic layer / third magnetic layer provided adjacent to the first magnetic layer. The layer is CoCr, CoCrPt, CoCrTa, or
A magnetoresistance effect element comprising an alloy containing these as main components. 2. A magnetic layer having a different coercive force being laminated via a nonmagnetic thin film layer, and a first magnetic layer and a second magnetic layer / nonmagnetic layer / second magnetic layer provided adjacent to the first magnetic layer. A magnetoresistive element comprising three magnetic layers, or a magnetoresistive element comprising a first magnetic layer and a nonmagnetic layer / third magnetic layer provided adjacent to the first magnetic layer. A magnetoresistive element, wherein the layer is made of SmCo, NdFe, or an alloy containing these as a main component. 3. The magnetoresistive element according to claim 1, wherein Cr is used as an underlayer of CoCr, CoCrPt or CoCrTa constituting the first magnetic layer according to claim 1. 4. The magnetoresistive element according to claim 1, wherein the second magnetic layer is made of NiFe, NiFeCo, F
A magnetoresistance effect element comprising eCo, Co, or an alloy containing these as a main component. 5. The magnetoresistive element according to claim 1, wherein the third magnetic layer is made of NiFe, NiFeCo, F
A magnetoresistance effect element comprising eCo, Co, or an alloy containing these as a main component. 6. The magnetoresistance effect element according to claim 1, wherein the nonmagnetic layer is made of Cu or an alloy containing Cu as a main component. 7. The magnetoresistance effect element according to claim 1, wherein the nonmagnetic layer is made of Au or an alloy containing Au as a main component. 8. The magnetoresistive element according to claim 1, wherein the nonmagnetic layer is made of Ag or an alloy containing Ag as a main component. 9. A first magnetic layer and a second magnetic layer / non-magnetic layer / third magnetic layer formed adjacent to the first magnetic layer, or a first magnetic layer and the first magnetic layer. In the method for manufacturing a magnetoresistive element in which magnetic layers each having a different coercive force, comprising a nonmagnetic layer and a third magnetic layer formed adjacent to each other, are stacked via a nonmagnetic thin film layer, the first magnetic layer Using CoCr, CoCrPt, CoCrTa, SmCo or NdFe as a heat treatment in a temperature range of 150 to 250 ° C. 10. A yoke type MR head in which an MR element is retracted from an ABS surface, wherein one of the magnetoresistive effect elements according to claim 1 is used. head. 11. A shield type MR head in which an MR element is sandwiched between soft magnetic layer shield films, wherein one of the magnetoresistive effect elements according to claim 1 is used. -Type MR head. 12. The method according to claim 1, wherein
At least one of the second magnetic layer and the third magnetic layer is Ni
A magnetoresistive sensor formed of a material selected from the group consisting of Fe, NiFeCo, FeCo, and Co;
Means for flowing a current through the magnetoresistive sensor, and a change in the specific resistance of the magnetoresistive sensor, wherein the direction of the magnetization of the second magnetic layer according to the magnetic field to be detected is based on the rotation difference of the magnetization of the third magnetic layer. Means for sensing magnetic field. 13. The method according to claim 1, wherein the second magnetic layer is made of Co or NiFeC.
o, and the third magnetic layer is made of NiFe or NiFeC.
13. The magnetoresistive sensing system according to claim 12, comprising o. 14. In the magnetoresistive sensor, the nonmagnetic layer is formed of a material selected from the group consisting of Cu, Au, Ag, an alloy containing these as a main component, or a mixture thereof. 13. The magnetoresistive sensing system according to claim 12, wherein: 15. A magnetic recording medium having a plurality of tracks for recording data, and a conversion device for converting a magnetic field intensity into an electric intensity, wherein the magnetic recording medium is provided between the magnetic recording medium and the conversion device. First, second and third layers of ferromagnetic material maintained at close spacing with respect to the magnetic recording medium during the relative movement of the magnetic recording medium and separated by a layer of non-magnetic metal material; The second and third layers of ferromagnetic material that are perpendicular to CoCr and Co adjacent to the second layer.
A magnetic transducer comprising a first magnetic layer made of CrPt, CoCrTa, SmCo, NdFe or an alloy containing these as a main component; and a magnetic transducer for moving the magnetic transducer to a selected track of the magnetic recording medium. Actuator means coupled to the transducer and the magnetic transducer for detecting a change in resistance in the magnetic transducer due to a magnetic field resulting from a magnetic domain recorded on the recording medium. A magnetic recording / reproducing system, comprising: connected detecting means. 16. A capping layer having a resistive sensor deposited on said third layer, and lead wire means deposited on said capping layer for connecting said magnetic transducer to said detecting means. The magnetic recording / reproducing system according to claim 15, further comprising: