JPH0567525A - Magnetic laminated body, its manufacture, and manufacture of magneto-resistance effect element - Google Patents

Abstract

PURPOSE:To obtain a magnetic laminated body which shows a large magneto- resistance change and can change the intensity of its operating magnetic field showing a big magneto-resistance change by piling up magnetic thin films containing one or more kinds among Fe, Co, and Ni and Ag thin films on a single-crystal-like buffer layer containing one or more kinds among Ag, Au, and Cu, and so on. CONSTITUTION:This magnetic laminated body is composed of a multilayered film 2 formed by piling up magnetic thin films containing at least one or more kinds among Fe, Co, and Ni and Ag thin films on a single-crystal-like buffer layer 1 containing at least one or more kinds among Ag, Au, and Cu. For example, after an Ag buffer layer 1 having a thickness of 739Angstrom is formed on a MgO (100) single-crystal substrate 3, the surface of which is polished to a mirror surface, by an MBE method, the crystal structure of the layer 1 is improved to a single-crystal state by annealing the layer 1 in a superhigh vacuum tank. Then, the multilayered film 2 is formed by alternately forming by magnetic Co thin films having a film thickness of 6Angstrom and Ag thin films having a film thickness of 21Angstrom 30 times by vapor-deposition by using the MBE method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic laminate, a method for manufacturing the same, and a method for manufacturing a magnetoresistive effect element (MR element).

[0002]

2. Description of the Related Art MR elements such as various magnetoresistive sensors (MR sensors) and magnetoresistive heads (MR heads) measure the magnetic field strength and its changes by detecting changes in the electrical resistance of a magnetic film due to a magnetic field. Generally, it is required that the rate of change in magnetoresistance at room temperature is large and the operating magnetic field strength is small.

As a magnetic film of an MR element, a Fe--Ni alloy (permalloy) which utilizes the anisotropic magnetoresistive effect has been used.
Ni-Co alloys are typically used. But,
In Fe—Ni alloys and Ni—Co alloys, the operating magnetic field strength is small, but the magnetoresistance change rate is small at 2 to 5%.

On the other hand, with the progress of thin film technology, artificial lattices using the molecular beam epitaxy (MBE) method have appeared. This artificial lattice has a structure in which thin films having a thickness on the order of atoms of a metal, which are formed by using a molecular beam epitaxy (MBE) method, are periodically laminated, and exhibit characteristics different from those of a bulk metal.

As one of such artificial lattices, a giant magnetoresistive variable material of a Fe / Cr type magnetic laminated body in which Fe and Cr are alternately laminated has been developed. In this one, Cr
Fe thin films sandwiching the thin film are magnetically coupled antiparallel to each other. Then, the spin of Fe is aligned in one direction by the external magnetic field, and the resistance decreases accordingly. As a result, it shows a huge magnetoresistance change of 46% at 4.2K and 16% at room temperature (Physical Review Letters 61, 247).
2 pages, 1988 etc.).

However, although the Fe / Cr type magnetic laminate has a large magnetoresistance change rate (MR change rate), the operating magnetic field strength is extremely large at about 20 kOe, which is a practical limitation as an MR element.

Since then, active research and development have been started all over the world for the artificial lattice magnetic layered body exhibiting such antiferromagnetism. To date, Co / Cr type and Co / Ru type magnetic layered bodies have been used. , Antiferromagnetic spin interlayer coupling has been discovered. (Physical Review Letters Volume 64, 230
4 pages, 1990). However, the MR change rate is
6./6.5% (4.5K) for Cr / Cr system and 6.% for Co / Ru system.
It is an extremely small value of 5% (4.5K).

Therefore, the inventors of the present invention aim to develop a magnetic laminated body which exhibits a giant magnetoresistance change and can reduce the operating magnetic field strength exhibiting the giant magnetoresistance change and can change the operating magnetic field intensity. Various studies were conducted. As a result, as Japanese Patent Application No. 3-186906, F
a magnetic thin film containing at least one of e, Co and Ni;
We have proposed a magnetic laminate in which a thin film and a thin film are laminated by a molecular beam epitaxy method. This one has an easy axis of magnetization in the plane,
The in-plane squareness ratio Br / Bs is 0.5 or less, it has antiferromagnetic spin alignment, shows a giant magnetoresistance change rate even in a magnetic field as low as several kOe, and reaches a maximum of 20% at room temperature. Giant magnetoresistance change rate can be obtained.

[0009]

SUMMARY OF THE INVENTION The main object of the present invention is to further increase the magnetoresistance change rate of the previously proposed (Fe, Co, Ni) / Ag type magnetic layered body and to achieve an extremely large magnetoresistance change. It is to provide a magnetic laminate capable of changing the operating magnetic field strength showing a giant magnetoresistance change, a method for manufacturing the same, and a method for manufacturing a magnetoresistance change element.

[0010]

The above objects are achieved by the present invention described in (1) to (8) below.

(1) A multilayer film in which a magnetic thin film containing at least one of Fe, Co and Ni and an Ag thin film are laminated on a single crystal buffer layer containing at least one of Ag, Au and Cu. A magnetic laminated body characterized by the above.

(2) The multilayer film comprises a magnetic thin film having a thickness of 2 to 60 A and containing at least one of Fe, Co and Ni;
The magnetic laminate according to (1) above, which is obtained by laminating an Ag thin film having a thickness of -60 A while epitaxially growing it by a molecular beam epitaxy method.

(3) The magnetic laminate according to the above (1) or (2), which has an easy axis of magnetization in the plane and has an in-plane squareness ratio of 0.5 or less Br / Bs.

(4) The magnetic laminate according to any one of (1) to (3), which exhibits antiferromagnetism.

(5) The thickness of the buffer layer is 100 to 2
The magnetic laminate according to any one of (1) to (4) above, which has a magnetic field intensity of 000 A.

(6) A single crystal buffer layer containing at least one of Ag, Au and Cu is formed on a substrate,
A method for producing a magnetic laminated body, comprising forming the multilayer film according to any one of (1) to (5) on the buffer layer.

(7) The method for producing a magnetic laminate according to the above (6), wherein the buffer layer is formed by a molecular beam epitaxy method and then annealed at 150 to 500 ° C.

(8) A magnetic laminate is obtained by the method described in (6) or (7) above, a substrate is adhered to the surface of the multilayer film of this magnetic laminate, and then the substrate and the buffer layer are removed, A method of manufacturing a magnetoresistive element, comprising patterning the multilayer film.

[0019]

Specific Structure The specific structure of the present invention will be described in detail below.

The magnetic laminate of the present invention has a buffer layer on the substrate. The buffer layer should just contain at least 1 sort (s) of Ag, Au, and Cu, and is substantially Ag, Au.
Alternatively, other than those formed of Cu, alloys of these two or three kinds may be used. Alternatively, in some cases, an alloy containing 1 to 3 of these at 30 at% or more may be used.

The buffer layer is substantially a single crystal and has a (100) orientation, and in the high speed reflected electron diffraction (RHEEP) pattern, the <010> direction and the <01> direction.
Streaks with clear equal intervals are observed in the 1> direction, and ring-shaped diffraction is substantially absent.

The thickness of the buffer layer is 100-2000A.
More preferably 200-1500 A, especially 400-10
It is preferably 00A. If the buffer layer is too thick, it wastes time and cost, and if it is too thin, the original bulk lattice constant of the buffer layer cannot be maintained, and the function as the buffer layer is lost.

With such a buffer layer, the substantial magnetoresistance change rate, which is a resistance change excluding the resistance of the buffer layer, is improved by about 2 to 8 times.

The material of the substrate used is magnesia M
gO (100), gallium-arsenic GaAs (100),
Other common tetragonal single crystal substrates can be used. The thickness of the substrate is not particularly limited, but it is preferably about 0.1 to 3 mm when removing the substrate described later.

A magnetic thin film containing a plurality of iron group elements is formed on the buffer layer formed on such a substrate, and each magnetic thin film is alternately laminated with an Ag thin film which is a non-magnetic intermediate layer. Has been done. The magnetic thin film in the present invention is Fe,
Any material containing at least one of Co and Ni may be used, and in addition to an alloy formed substantially of Fe, Co or Ni, an alloy of two or three of these may be used. Alternatively, it may be an alloy containing 1 to 3 of these at 30 at% or more.

The thickness of the magnetic thin film is less than 60A, especially 50A.
Or less, more preferably 40 A or less, and further preferably 2
It is preferably 0 A or less. If the thickness exceeds 60 A, the distance between the magnetic elements between layers becomes relatively large, the antiferromagnetic coupling is lost, and the giant magnetoresistance change is not exhibited. In addition, the thickness of the magnetic thin film is 2A or more,
It is preferably 4 A or more. If it is less than 2 A, the magnetic elements will not be continuously arranged in the forming surface, and ferromagnetism will not be exhibited.

The Ag thin film is preferably formed only from Ag and has a thickness of 60 A or less, particularly 50 A or less,
It is more preferably 45 A or less. 60
Beyond A, the distance between the magnetic thin films increases, and antiferromagnetic coupling is lost. The thickness of the Ag thin film is 2
It is preferably A or more. If it is less than 2 A, it will not be a continuous film and the function of the non-magnetic intermediate layer will be lost.

The magnetic thin film, the Ag thin film and the artificial lattice multi-layered film thereof are substantially single crystals and have a (100) orientation due to the buffer layer. And this (10
0) Epitaxial growth is confirmed by the clear observing of streaks at equal intervals in the <010> direction and the <011> direction in the RHEED pattern, as described above.

In such a case, in the magnetic layered body of the present invention, the magnetic exchange coupling energy changes while periodically oscillating due to the repetition period of the magnetic layer, especially the thickness change of the Ag thin film. Although such a fact has been recently reported in the magnetic laminated body by sputtering, it is the first discovery in the magnetic laminated body artificial lattice of the present invention by the MBE method.

More specifically, the thickness of the Ag thin film is set to 2 to 60 mainly by vibration type magnetic coupling depending on the thickness of the Ag thin film.
When changed within the range of A, the saturation applied magnetic field Hsat changes periodically. Hsat changes periodically in the range of 1 kOe to 10 kOe, and the maximum and minimum values of Hsat also change. At this time, the magnetoresistance change rate also periodically changes and vibrates, but as a substantial magnetoresistance change rate, a giant magnetoresistance change rate exceeding 20% at room temperature and reaching 30% can be obtained. Area exists.

As a result, by selecting the thickness of the Ag thin film in the range of 2 to 60 A, the operating magnetic field strength of 0.01 to
At 20 kOe, a magnetic laminate having a substantial magnetoresistance change rate of 1 to 50% at room temperature can be freely designed. The substantial magnetoresistance change rate is the magnetoresistance change rate of the multilayer film after subtracting the resistance of the buffer layer.

The thickness of the magnetic thin film and the Ag thin film can be measured by a transmission electron microscope, a scanning electron microscope, Auger electron spectroscopy, etc., and the crystal structure etc. is X.
It can also be confirmed by line diffraction or the like.

In the magnetic laminated body of the present invention, the number of laminated magnetic thin films and the number of repetitions of the magnetic thin film / Ag thin film unit are not particularly limited and may be appropriately selected according to the target magnetoresistance change rate and the like. In order to obtain a sufficient rate of change in magnetic resistance, the number of repetitions is preferably 2 or more, particularly 8 or more. The larger the number of repetitions, the larger the proportion of free electrons scattered, which is preferable. Also, if the number of times of repetition is too large, the deterioration of the film quality becomes large and the improvement of the characteristics cannot be expected.
It is preferably 0 times or less. The long-period structure is
Small angle X-ray diffraction pattern, 1 according to the repetition cycle
It can be confirmed by the appearance of secondary and secondary peaks.

Such a laminate exhibits antiferromagnetism as a result of antiferromagnetic coupling between the layers of the magnetic thin film. Antiferromagnetism can be easily confirmed by polarized neutron diffraction, for example. In addition, as a result of showing antiferromagnetism, the applied magnetic field in the plane of the laminate was measured by a vibrating magnetometer or BH tracer
When the magnetization curve or the BH loop is measured, the squareness ratio Br
/ Bs becomes a value of 0.5 or less, particularly 0.3 or less, and Br / Bs becomes almost 0 in some cases. At this time, the applied magnetic field-magnetization curve and the BH loop demagnetization curve and the magnetization curve are extremely close to each other. And vibration type magnetometer and B-H
When the easiness of magnetization of the in-plane surface and the in-plane normal direction surface or the anisotropic energy is measured with a tracer or a torque meter, the easy magnetization axis exists in the surface. Note that, in FIG. 3, the applied magnetic field-magnetization curves in the plane of the laminate and the normal plane are shown as a curve A and a curve B, respectively. Br / in plane
If Bs exceeds 0.5, the ratio of antiferromagnetism inside the laminated body is rapidly reduced, and as a result, the MR change rate is reduced.

The Journal of Applied Magnetics of Japan 13,335-
In 338 (1989), C using a high frequency sputtering method is used.
An artificial lattice magnetic laminate of the o / Ag and Fe / Ag systems is described. However, this is a laminated body for utilizing the polar Kerr effect, has perpendicular magnetic anisotropy, and has MR
When used as an element, the MR change rate is low. Also, Japane
se Journal of Applied Physics, Volume 26 Supplement 26
-3,1451 pages, 1987, Co / Ag based artificial lattice magnetic laminates by sputtering method are also reported. In this case, the electrical resistance (sheet resistance) of the laminates is reported.
And the stacking period dependence of Co and Ag are mainly described, there is no report showing antiferromagnetism, and the MR change rate has not been investigated.

Further Superlattices and Microstructure
s Vol. 4, No. 1, p. 45, 1988, describes the Hall coefficient and the magnetoresistive effect of a magnetic laminate of Fe, Co, and Ni and Ag produced by the sputtering method. However, the Co / Ag magnetoresistive effect described here is brought about by the magnetic domain structure of Co that is oriented in various directions when a weak applied magnetic field is applied. Fundamentally different.

Furthermore, the Journal of Applied Magnetics of Japan 13,339
-342 (1989), an artificial lattice magnetic laminate of Co / Au system by a molecular beam epitaxy method is reported, which also has perpendicular magnetic anisotropy and an MR change rate of 1
% (0.5 kOe, room temperature), which is low.

In order to produce the magnetic layered product of the present invention, it is preferable to use the molecular beam epitaxy (MBE) method.
In the case of the present invention, since the layer thickness of the magnetic thin film and the Ag thin film to be formed is extremely thin, it is necessary to adhere slowly. In order to avoid mixing of impurities during the film formation, it is necessary to form the film in the ultra-high vacuum region. Further, the energy of the adhered particles is preferably as low as possible so that mutual diffusion does not occur when the respective layers are formed and antiferromagnetism is not lost. The MBE method is most suitable for this purpose.

The MBE method is one of ultra-high vacuum vapor deposition methods, and is a method for growing a thin film by adhering molecules or substances evaporated from a vapor deposition source to a substrate surface in ultra-high vacuum. Specifically, the evaporation source is selected by opening and closing the shutter, and the magnetic thin film and the non-magnetic thin film are alternately deposited while measuring with a film thickness meter to form a multilayer film.

At this time, the ultimate pressure is usually about 10 ^-11 to 10 ^-9 Torr, and the pressure during vapor deposition is 10 ^-11 to 10 ^-7 Torr.
It is preferably r, particularly about 10 ⁻¹⁰ to 10 ⁻⁷ Torr. The film forming rate is 0.01 to 1 A / sec, and especially 0.
It is preferably about 05 to 0.5 A / sec.

When forming a multilayer film by epitaxial growth, it is preferable to keep the substrate temperature at 100 ° C. or lower, particularly 60 ° C. or lower. If the substrate temperature is too high, each element causes mutual diffusion at the interface portion, and the quality of the artificial lattice film deteriorates. The magnetic thin film may be formed in a magnetic field to enhance the in-plane magnetic anisotropy.

The MBE method is also used for forming the buffer layer carrying such an artificial lattice multilayer film. At this time, the film forming rate is 0.01 to 1 A / sec, particularly 0.05 to 0.3 A / sec.
sec is preferred. If the film formation rate is too high, the crystal structure is disturbed, and it becomes difficult to obtain a single crystal buffer layer. However, if the film formation rate is too slow, time and cost are wasted. The substrate temperature during film formation of the buffer layer is preferably 200 ° C. or lower, particularly 100 ° C. or lower. If the substrate temperature is too high, island-like growth will occur, and undulations and irregularities will occur on the buffer surface.

After forming such a film, it is preferable to perform annealing in order to obtain a single crystal buffer layer having a smooth surface. The annealing pressure is 10 ^-11 to 10 ^-8 Torr,
Annealing temperature 150-500 ° C, annealing time 1-60
It is preferable to set to minutes. If the annealing temperature is too high or the annealing time is too long, the surface becomes uneven.

After that, the artificial lattice multilayer film is epitaxially grown on this buffer layer by the MBE method.

Such a magnetic laminate is used in various magnetoresistive elements (MR elements) such as magnetoresistive sensors (MR sensors) and magnetoresistive heads (MR heads). In order to manufacture a magnetoresistive element from the magnetic laminate having the buffer layer of the present invention, it is preferable to follow the procedure described below.

First, as shown in FIG. 1A, a magnetic laminate having a buffer layer 1 and a multilayer film 2 on a single crystal substrate 3 is obtained according to the method described above. Then, FIG.
As shown in (b), another substrate 5 is integrated with the multilayer film 2 via the adhesive layer 4.

There is no limitation on the material of the substrate 5 to be used, and in addition to the amorphous glass substrate and the crystallized glass substrate, various substrates usually used, for example, magnesia, sapphire, silicon, alumina, strontium titanate, barium titanate, niobate. Lithium, various oxides such as calcium titanate, and substrates such as alumina-titanium carbide can be used, but non-alkali glass is preferable from the viewpoint that cost and time do not adversely affect the multilayer film. .. The thickness may be about 0.3-1 mm. As the adhesive to be used, any of various known adhesives can be used.

After that, as shown in FIG. 1C, the substrate 3 and the buffer layer 1 are removed. More specifically, the single crystal substrate 3 and the buffer layer 1 are removed in this order by lapping, polishing, or the like. At this time, the buffer layer 1 should be left on the multilayer film 2 by a thickness of d. d is preferably as close to 0 as possible, but is preferably about 100 A or less. When d becomes large, the current flowing through the remaining single crystal buffer layer increases, and the apparent magnetoresistance change rate decreases. However, when d is too small, the artificial lattice multilayer film is damaged and the rate of change in magnetoresistance decreases, so d is preferably 50 to 100A.

Next, the multilayer film 2 is patterned to
The electrodes 6 are formed by attaching the electrodes, and the protective layer and the leads 7 are formed to manufacture the magnetoresistive effect element shown in FIGS.

Although the buffer layer is removed in the above, it goes without saying that the magnetoresistive element may be produced without removing the buffer layer.

[0050]

EXAMPLES The present invention will be described in more detail with reference to specific examples.

Example 1 Magnesia MgO (1) with a thickness of 0.5 mm whose surface was mirror-polished
00) An Ag film was formed on the single crystal substrate by the MBE method.
Ultimate pressure is 7 × 10 ^-11 Torr, operating pressure is 7 × 10 ^-10 T
orr, the film formation rate was 0.1 A / sec, the substrate was kept at 22 ° C., and vapor deposition was performed while rotating at 30 rpm.
An Ag buffer layer of A was formed.

FIG. 4A shows the R of the buffer layer immediately after the film formation.
The HEED pattern is shown. In the RHEED pattern of the Ag buffer layer immediately after film formation, streaks at equal intervals are observed in both <010> and <011> directions, but at the same time ring-shaped diffraction is also observed. This indicates that the crystal structure of the buffer layer immediately after film formation includes a small amount of a polycrystalline part in addition to the single crystal part.

After forming the buffer layer, the pressure is adjusted to 8 × 10 ^-9 Torr.
Annealing was performed for 15 minutes at 350 ° C. The RHEED pattern after annealing is shown in FIG. By annealing, the streak becomes extremely clear in both the <010> and <011> directions.
It can be seen that the (100) single crystal Ag buffer layer is formed. A flat surface can be obtained by keeping the substrate temperature at the time of forming the buffer layer low at 100 ° C. or lower. However, the crystal structure is somewhat disturbed, and a polycrystal part is included. Therefore, by annealing this buffer layer in an ultra-high vacuum chamber, keeping the surface smooth,
A single crystal can be obtained by improving the crystal structure.

Next, the inside of the tank was set to 3 × 10 ^-10 Torr,
On this buffer layer, a Co magnetic thin film and an Ag thin film were alternately deposited, and 6 A of Co and 21 A of Ag were set as one unit, and this was laminated 30 times to prepare a magnetic laminate sample. In the following, such a case is indicated as [Co (6) -Ag (21)] ₃₀ . The thickness of each thin film was measured by a transmission electron microscope.

Deposition is carried out by the MBE method, the operating pressure is 9.7 × 10 ^-10 Torr, and the film forming rate is 0.1 A /
In the case of sec and Ag, it was set to 0.2 A / sec, and vapor deposition was performed while rotating the substrate at 30 rpm. The substrate temperature during vapor deposition was 45 ° C.

The RHEED pattern of the artificial lattice multilayer film is shown in FIG. Clear streak was observed in both the <010> and <011> directions, indicating that the (100) epitaxial growth was favorably performed.

The applied magnetic field-magnetization curve was measured by an oscillating magnetometer. In addition, the sample was made into a strip of 0.3 mm x 1.0 mm, and the resistance when the external magnetic field was changed up to -20 to +20 kOe was measured by the 4-terminal method, and the real magnetic resistance (MR) change rate ΔR / R I asked. Measuring current is 1.0
The external magnetic field was applied from different directions. MR
The rate of change ΔR / R is the maximum resistance value Rmax and the minimum resistance value R
and calculated as ΔR / R = (Rmax−Rmin) / Rmin × 100 (%). In this case, the resistance R of the entire laminate is
It is assumed that t is a parallel combination of the resistance Rb of the buffer layer and the substantial magnetic resistance Rm of the multilayer film, and Rm = Rt × Rb / (Rb−
Rt) and (Rb = 5.4Ω) are used to calculate Rm from Rt at each applied magnetic field, and from this Rm, ΔR is calculated.
/ R was calculated.

The MR change rate is shown in FIG. In Figure 5, Trans
Is when an external magnetic field is applied in the sample plane in the direction perpendicular to the current, Long is when an external magnetic field is applied in the sample plane, in the direction parallel to the current, and Normal is when the external magnetic field is applied in the sample normal direction. Is the result of. In Trans, at room temperature, a real MR change rate of 29.9% was obtained with an applied magnetic field of 20 kOe.
Further, at 77K, 118.2% was obtained.

Further, the applied magnetic field-magnetization curve in the in-plane direction of the sample is shown in FIG. 6 (a). The squareness ratio in this case is 0.1
Met.

From these, it was estimated that the laminate has an easy axis of magnetization in the plane, a small squareness ratio, and exhibits antiferromagnetism. In fact, the polarized neutron diffraction results also show diffraction lines at the Bragg angle corresponding to the double period of the thickness of the laminated unit,
Antiferromagnetic coupling between layers was confirmed.

In addition, the Ag buffer layer and [Co
(6) -Ag (21)] ₃₀ multilayer film was formed to form a magnetic laminate. It was not confirmed that neither the buffer layer nor the multilayer film after annealing had a single crystal in the RHEED pattern. As shown in FIG. 6 (b), the in-plane Br / Bs of this material had an easy axis of magnetization in the plane of 0.1 and exhibited antiferromagnetism.

This laminate has an MR of 14% at room temperature and 26.1% at 77K and 20 kOe, as shown in FIG.
The rate of change was shown. From these, the effect of the single crystal buffer layer of the present invention is clear.

Example 2 An experiment was conducted by changing the thickness t of the Ag thin film in [Co (6) -Ag (t)] ₇₀ in Example 1 to various values.

When the saturation applied magnetic field Hsat was measured when the thickness of the Ag thin film was changed, it was confirmed that Hsat periodically oscillated and changed due to the change in the thickness of the Ag thin film. The maximum peak of vibration is t = 9A and 2
The antiferromagnetic coupling energy J _AF is 5 A, and J _AF = Hsat · Ms · t (Co) / 4 t (Co) is calculated from the thickness of the Co layer to 0.12 erg / cm
^The secondary peak at ² and 25 A was estimated to be 0.15 erg / cm ³ .

The above-described effects were equally realized in the magnetic thin film of Ni or Fe or the single crystal buffer layer of Au or Cu.

[0066]

EFFECT OF THE INVENTION The multilayer film of the present invention can obtain a larger giant magnetoresistance change in a lower magnetic field as compared with the conventional magnetoresistance change laminated body by antiferromagnetic coupling. Since this multilayer film is formed by epitaxial growth on the single crystal buffer layer, the magnetoresistive change ratio is further increased. Then, by utilizing the oscillation cycle change of the magnetic coupling energy, an arbitrary magnetic change of 1 to 150% can be obtained in an arbitrary operating magnetic field of 0.01 to 20 kOe. Further, it is characterized in that different magnetoresistance change characteristics can be obtained depending on the external magnetic field direction. further,
If the buffer layer is removed to form a magnetoresistive element, extremely high sensitivity can be obtained.

[Brief description of drawings]

FIG. 1 is a front view for explaining a process for manufacturing a magnetoresistive element using the magnetic laminate of the present invention.

FIG. 2 is a front view of a magnetoresistive element obtained according to the present invention.

FIG. 3 is a plan view of a magnetoresistive element obtained by the present invention.

FIG. 4 is a drawing-substituting photograph showing a high-speed reflection electron beam diffraction pattern after each step in the method for producing a magnetic laminate of the present invention.

FIG. 5: Applied magnetic field and magnetic resistance (M
It is a graph which shows the relationship with R) change rate.

FIG. 6 is a graph showing an applied magnetic field-magnetization curve of the magnetic layered body of the present invention.

FIG. 7 is a diagram showing a magnetic field applied to another magnetic laminated body and a magnetic resistance (M
It is a graph which shows the relationship with R) change rate.

[Explanation of symbols]

 1 Buffer Layer 2 Multilayer Film 3 Base 4 Adhesive Layer 5 Substrate 6 Electrode 7 Lead

Claims (8)

[Claims] 1. Fe, Co and Ni are formed on a single crystal buffer layer containing at least one of Ag, Au and Cu.
And a magnetic thin film containing at least one of the above and a Ag thin film. 2. The multi-layered film having a thickness of 2 to 60 A
a magnetic thin film containing one or more of e, Co and Ni;
The magnetic laminate according to claim 1, which is a laminate of the Ag thin film having a thickness of 60 A and being epitaxially grown by a molecular beam epitaxy method. 3. The magnetic laminate according to claim 1, which has an easy axis of magnetization in the plane and has an in-plane squareness ratio of 0.5 or less Br / Bs. 4. The magnetic laminated body according to claim 1, which exhibits antiferromagnetism. 5. The buffer layer has a thickness of 100 to 200.
The magnetic laminated body according to any one of claims 1 to 4, which has an electric current of 0 A. 6. A single-crystal buffer layer containing at least one of Ag, Au and Cu is formed on a substrate, and the multilayer film according to claim 1 is formed on the buffer layer. A method of manufacturing a magnetic laminated body, which comprises forming the magnetic laminated body. 7. The method for producing a magnetic laminate according to claim 6, wherein the buffer layer is formed by a molecular beam epitaxy method and then annealed at 150 to 500 ° C. 8. A magnetic laminated body is obtained by the method according to claim 6 or 7, a substrate is adhered to the surface of the multilayer film of the magnetic laminated body, and then the substrate and the buffer layer are removed to form the multilayer film. A method for manufacturing a magnetoresistive effect element, which comprises patterning.