JPH08203035A - Magnetoresistance effect film, magnetoresistance effect element, magnetic head and magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To obtain a high rate of change of magnetoresistance even at a relatively low magnetic field by using an amorphous magnetic alloy for at least one layer of a magnetic layer in a magnetoresistance effect layer having a three-layer film and a five-layer film of a magnetic layer and non-magnetic layer or an antiferromagnetic layer on or under the magnetic layer. CONSTITUTION: The magnetoresistance effect layer having three-layer film laminating the magnetic layer, the non-magnetic layer and the magnetic layer, the five-layer film laminating the magnetic layer, the non-magnetic layer, the magnetic layer, the non-magnetic layer and the magnetic layer or the anti-magnetic layer on or under the magnetic layer is provided. In this effect layer, the high rate of change of the magnetoresistance is obtained at a relatively low magnetic field. That is, it seems that a soft magnetic characteristic is improved when the amorphous magnetic alloy is used. At this time, in a CoFeB layer being the amorphous layer having a rate of change of the magneto-resistance (MR ratio) of 5% for example is obtained within a change of the magnetic field of 280A/m as the center of the magnetic field H of 800A/m, and a magnetic sensitivity becomes to 17.8%KAm-<1> . That is, the high rate of change of the magnetoresistance is obtained at the relatively low magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect film having a high magnetoresistive effect in a low magnetic field, a magnetoresistive effect element using this magnetoresistive effect film, a magnetic head using this element, and this magnetic head. The present invention relates to a magnetic recording / reproducing device used.

[0002]

2. Description of the Related Art Conventionally, permalloy has been used as a magnetoresistive effect material for reproducing magnetic heads. However, the magnetic resistance change rate of permalloy is as low as about 3%, and a material having a higher magnetic resistance change rate than that is required. A Fe / Cr magnetic film having a multilayer structure has been proposed as a material having a higher magnetoresistance change rate than this permalloy.
An e / Cu / NiFe / FeMn / Ta film has also been proposed.

[0003]

However, the Fe / Cr magnetic film having the above-mentioned multilayer structure requires a magnetic field as high as 800 KA / m in order to obtain a sufficient magnetoresistance change rate.
It could not be used for a magnetoresistive effect element or a magnetic head that needs to operate in a low magnetic field. Also, Ta /
The NiFe / Cu / NiFe / FeMn / Ta film shows a magnetoresistive change rate of 2.2% in a relatively low magnetic field, but it is not sufficient yet, and a material showing a higher magnetoresistive change rate in a low magnetic field is required. It was being done. An object of the present invention is to provide a magnetoresistive effect film, a magnetoresistive effect element, a magnetic head, and a magnetic recording / reproducing apparatus that exhibit a higher magnetoresistive change rate in a low magnetic field.

[0004]

In order to achieve the above object, in the present invention, a magnetic layer, a non-magnetic layer and a three-layer film in which a magnetic layer is laminated, a magnetic layer, a non-magnetic layer, a magnetic layer and a non-magnetic layer. In a five-layer film in which a magnetic layer and a magnetic layer are laminated, or in a magnetoresistive film having an antiferromagnetic layer above or below the magnetic layer, an amorphous magnetic alloy is used for at least one of the magnetic layers. In the magnetoresistive film, the angle formed by the magnetization directions of the magnetic layers sandwiching the non-magnetic layer changes, and the amorphous magnetic alloy has a B concentration of 10 to 25a.
That is, a Co—Fe—B-based amorphous magnetic alloy with t% is used. At least one of the magnetic layers of the magnetoresistive film is Co, Ni--Fe or Ni--Fe--.
It is an alloy containing Co as a main component, and at least one layer of the nonmagnetic layer is Cu, Ag, or Au.

Further, the angles formed by the easy magnetization directions caused by the magnetic anisotropy of the magnetic layers sandwiching the non-magnetic layer of the magnetoresistive film are different, and at least one of the magnetic layers of the magnetoresistive film has an exchange bias magnetic field. That is, an antiferromagnetic layer for applying is applied. Further, the magnetoresistive effect element of the present invention,
That is, at least part of the magnetoresistive film was used. Further, the magnetic head of the present invention uses the magnetoresistive effect element at least in part. further,
The magnetic recording / reproducing apparatus of the present invention uses the above magnetic head in at least a part thereof.

To further explain the present invention, the amorphous magnetic alloy of the present invention is a Co--Fe--B type amorphous magnetic alloy, and the Co--Fe--B type amorphous magnetic alloy is B1.
0-25at%, Co81-67at%, Fe9-
The alloy is 7.5 at%. The magnetic layer is made of Co, N
Metals or alloys such as i-Fe and Ni-Fe-Co, N
i-Fe is Ni35-8 known as permalloy
0%, balance Fe, Ni-Fe-Co is F
e16-20%, Ni66-11%, Co18-73%
belongs to. Further, the antiferromagnetic layer of the present invention is made of Ni
O, NiMn, CoMn, FeMn and the like.

[0007]

According to the present invention, a magnetic layer, a non-magnetic layer and a magnetic layer are laminated in three layers, a magnetic layer, a non-magnetic layer, a magnetic layer, a non-magnetic layer and a magnetic layer are laminated in five layers, or a magnetic layer. In the magnetoresistive effect film having the antiferromagnetic layer above or below, by using an amorphous magnetic alloy for at least one of the magnetic layers, a high magnetoresistive change rate can be obtained in a relatively low magnetic field. It is considered that this is because the soft magnetic characteristics were improved by using the amorphous magnetic alloy. Further, since the magnetoresistive effect element of the present invention uses the magnetoresistive effect film having excellent characteristics described above, the magnetic head of the present invention uses at least part of the magnetoresistive effect element having excellent characteristics described above. Further, the magnetic recording / reproducing apparatus of the present invention can obtain a magnetic recording medium having excellent characteristics by using at least part of the magnetic head having the above characteristics.

[0008]

Embodiments of the present invention will be described below. Example 1 The following three-layer film and spin valve film were produced using a high frequency magnetron sputtering device. Ar pressure during spattering is 0.
68 to 1.32 Pa, film forming rate is 0.1 to 0.2 nm
/ S. A glass slide was used as a substrate, and an amorphous CoFeB layer, a Cu layer, and a Co layer were sequentially formed thereon, and CoFeB (6 nm) / Cu (2.1 nm) / Co
A (1.5 nm) film was prepared. The composition of CoFeB of the amorphous magnetic alloy is Co: 72 at%, F
e: 8 at%, B: 20 at%. The characteristics of this film are as shown in FIG.
Of 5% is obtained with a magnetic field change of 280 A / m centering on a magnetic field (H) of 800 A / m, and the magnetic field sensitivity is 17.8.
% / KAm ⁻¹ .

FIG. 1 is a graph showing the relationship between H (magnetic field on the hard axis of magnetization) and MR ratio (rate of change in magnetoresistance) of the film. FIG. 2 is a graph showing the magnetic field of the easy axis of the film and the rate of change in magnetoresistance. The upper graph is an enlargement of H in the vicinity of 0 in the lower graph. The larger the gradient of the magnetoresistance change rate in FIG. 2 is, the higher the sensitivity is.
The magnetic field sensitivity of the above film was about three times that obtained with the conventional material mainly composed of NiFe alloy. It is considered that this is because the soft magnetic characteristics were improved by using the amorphous material.

Example 2 In the same manner as in Example 1, CoFeB (9 nm) / C
A film of u (2.1 nm) / Co (1.5 nm) was prepared. The composition of CoFeB of the amorphous magnetic alloy is as follows: Co: 72 at%, Fe; 8 at%, B: 20 at%.
%Met. The rate of change in magnetoresistance of this film was 3%.
When this film was heat-treated at 250 ° C. for 1 hour in a magnetic field of 12.8 kA / m, the magnetoresistive change rate increased to 4%. From this result, it was found that the film did not deteriorate even at 250 ° C., which is the temperature at which the film is heated for glass fusion. It is considered that this is because there is no deterioration of characteristics due to crystallization of the layer of amorphous material.

Example 3 In the same manner as in Example 1, NiO (50 nm) / C was prepared so that an exchange bias magnetic field from the antiferromagnetic layer was applied.
o (1.5nm) / Cu (2.1nm) / CoFeB
A (9 nm) / Cu (3 nm) film was prepared. The composition of CoFeB of the amorphous magnetic alloy is Co: 72
At%, Fe; 8 at%, and B: 20 at%. The characteristics of this film are as shown in FIG.
R / R) of 2.7% was obtained. This value is equivalent to that obtained with a conventional material mainly composed of NiFe alloy, and there was no deterioration in characteristics even after heat treatment at 250 ° C. Further, it has been found that this film is applied with an exchange bias magnetic field and can be used for magnetic head applications. The magnetization curve of this film is as shown in FIG.

Example 4 An example of the magnetoresistive element of the present invention using the magnetoresistive film of the present invention is shown in FIG. The magnetoresistive effect element of the present invention comprises the magnetoresistive effect film (1) of the present invention and two electrodes (2
_{It has} a structure in which it is sandwiched by ₁ , 2 ₂ ) and these are sandwiched by shield layers (3 ₁ , 3 ₂ ) from above and below. Embodiment 5 FIG. 6 shows an example of the recording / reproducing magnetic head of the present invention using the magnetoresistive effect element of the present invention. The recording / reproducing magnetic head of the present invention comprises a magnetoresistive film (1) and two electrodes (2) of the present invention.
₁ , 2 ₂ ) and a plurality of coils (5 ₁ , 5 ₂ ) between _two magnetic poles (4 ₁ , 4 ₂ ) on a magnetoresistive effect element composed of _two shield layers (3 ₁ , 3 ₂ ). 5 ₃ ) is sandwiched between the two.

The present invention is not limited to the embodiments in other points than the above, and it is needless to say that various modifications can be made without departing from the scope of the invention.

[0014]

EFFECTS OF THE INVENTION The present invention, having the above-mentioned structure, exhibits a high magnetoresistance change rate in a low magnetic field, and has a temperature of 250 ° C.
It has excellent characteristics that the characteristics do not deteriorate even if it is heated to a certain degree.

[Brief description of drawings]

FIG. 1 shows the CoFeB (6 nm) / Cu (2.
H of the hard axis of the film of 1 nm) / Co (1.5 nm)
6 is a graph showing the relationship between (magnetic field) and MR ratio (rate of change in magnetic resistance).

FIG. 2 is a graph showing the H (magnetic field) of the easy axis of the film of FIG.
It is a graph which showed the relationship of atio (magnetic resistance change rate).

FIG. 3 is NiO (50 nm) / Co (1.5 n) in which an exchange bias magnetic field from the antiferromagnetic layer is applied.
m) / Cu (2.1 nm) / CoFeB (9 nm) / C
7 is a graph showing the relationship between H (magnetic field) of u (3 nm) and ΔR / R (rate of change in magnetoresistance).

FIG. 4 is a magnetization curve of FIG.

FIG. 5 is a perspective view showing a part of the magnetoresistive effect element of the present invention.

FIG. 6 is a perspective view showing a part of a recording / reproducing magnetic head.

[Explanation of symbols]

1 Magnetoresistive film 2 ₁ , 2 ₂ Electrode 3 ₁ , 3 ₂ Shield layer 4 ₁ , 4 ₂ Magnetic pole 5 ₁ , 5 ₂ , 5 ₃ Coil

Claims (12)

[Claims] 1. A three-layer film in which a magnetic layer, a non-magnetic layer and a magnetic layer are laminated, a magnetic layer, a non-magnetic layer, a magnetic layer, a five-layer film in which a non-magnetic layer and a magnetic layer are laminated, and these three-layer films and A magnetoresistive effect film having an antiferromagnetic layer above or below a five-layer magnetic layer, wherein an amorphous magnetic alloy is used for at least one of the magnetic layers. 2. The magnetoresistive film according to claim 1, wherein the directions of magnetization of the magnetic layers sandwiching the nonmagnetic layer are different from each other. 3. The magnetoresistive film according to claim 1, wherein at least one of the magnetic layers is Co—F.
e-A magnetoresistive film characterized by being a B-based amorphous magnetic alloy. 4. The magnetoresistive film according to claim 3, wherein the Co—Fe—B-based amorphous magnetic alloy has a B concentration of 10 to 25 at%. 5. The magnetoresistive film according to claim 1, wherein at least one of the magnetic layers is C.
A magnetoresistive film characterized by being an alloy containing o, Ni-Fe or Ni-Fe-Co as a main component. 6. The magnetoresistive film according to claim 1, wherein at least one of the non-magnetic layers is Cu, Ag or Au. 7. The magnetoresistive film according to claim 1, wherein an angle formed by easy directions of magnetization caused by magnetic anisotropy of the magnetic layers sandwiching the nonmagnetic layer is different. And a magnetoresistive effect film. 8. A magnetoresistive effect film comprising a diamagnetic layer for applying an exchange bias magnetic field to at least one of the magnetic layers of the magnetoresistive effect film according to claim 1. Description: 9. A magnetoresistive effect element comprising the magnetoresistive effect film according to claim 1 in at least a part thereof. 10. A magnetic head using the magnetoresistive effect element according to claim 9 in at least a part thereof. 11. A composite type magnetic head comprising a combination of the magnetic head according to claim 10 and an induction type magnetic head. 12. A magnetic recording / reproducing apparatus using the magnetic head according to claim 10.