JPH08330645A - Magnetic detection element - Google Patents

Abstract

PURPOSE: To provide a magnetic detection element in which an element body is constituted of a thin film, which can detect magnetism by an MI(magnetic impedance) effect and can be handled easily with higher function than those of an element constituted of an amorphous wire. CONSTITUTION: A high-permeability magnetic film 12 is formed on the whole surface of a rectangular nonmagnetic substrate 10, conductive films 14 as terminals are formed at both ends in its length direction, and wires 18 are connected to the films by solder 16. The length direction of an element, i.e., the length direction of the magnetic film 12, is arranged so as to be along the application direction of an external magnetic field to an object to be detected. In addition, the magnetic film 12 is endowed with magnetic anisotropy in such a way that the direction of an axis of easy magnetization is perpendicular to the length direction inside a film face. A high-frequency current is applied to the magnetic film 12 via the wires 18 from both end parts in the length direction, a change in an impedance generated across both end parts in the length direction of the magnetic film 12 by the external magnetic field is converted into an electric signal, and an output can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensing element,
In particular, the present invention relates to a magnetic detection element that detects an external magnetic field by utilizing the magnetic impedance effect.

[0002]

2. Description of the Related Art Recently, magnetic sensors have been diversified with the rapid development of information equipment, measurement / control equipment, etc., but further miniaturization and higher precision are expected in the future. In the field of magnetic heads, miniaturization of digital magnetic recording devices is progressing. For example, in a hard disk of an external storage device of a computer or a digital compact cassette (DCC) of a digital audio, a conventional inductive magnetic head has a track width and Since a decrease in S / N occurs due to a decrease in relative speed, a magnetoresistive effect element (hereinafter abbreviated as MR element) is used in the reproducing head. However, the MR element does not depend on the speed of the medium and is suitable for taking out the output at a low speed, but since the resistance change rate is only a few percent, the MR element having a higher sensitivity is required for future high density. Development is desired.

Also in the field of sensors such as magnetic encoders, the magnetic flux leaking to the outside is extremely reduced due to the reduction of the magnetization pitch of the magnetized medium, and the sensitivity insufficiency of MR elements is becoming a problem.

Therefore, a magnetic detection element utilizing the magnetic impedance (hereinafter abbreviated as MI) effect disclosed in Japanese Patent Application Laid-Open No. 6-281712 has recently been attracting attention. This is because a high frequency current in the MHz band is passed through the wire of the magnetic material, and the magnetic permeability changes greatly due to the rotation of the magnetization due to the application of an external magnetic field from the state where the magnetic domain wall of the circumferential direction is hard to move. Changes in permeability cause changes in impedance.

The advantage of this element is that it is not excited in the lengthwise direction of the magnetic material, so there is no influence of the demagnetizing field, and the length of the element is 1 mm.
It is suitable for miniaturization because it can be shortened to the level below, and the resolution of magnetic flux detection can be as high as 10 ⁻⁵ Oe with respect to MR element having a low sensitivity of 0.1 Oe.
Further, the amount of impedance change is about 3% in the MR element, whereas the element using the MI effect can be changed in the order of several tens of percent.

In the element utilizing the MI effect, the inductance component of impedance changes greatly,
It is incorporated as the inductor L of the Colpitts oscillator shown in FIG. 7 and the multivibrator oscillator shown in FIG. 8, and changes in inductance due to an external magnetic field is converted into amplitude modulation, and the output after detection is taken out.

[0007]

The function of the element due to the MI effect is found in the amorphous wire, and the amorphous wire is excellent in productivity as a material. However, in the application to magnetic sensors, if the wire has a circular cross section and a diameter of several tens of microns,
It may be difficult to handle.

Specifically, for a recording medium having a recording wavelength of several microns or less, a circular tip having a diameter of several tens of microns cannot absorb the magnetic flux in the element due to a geometric loss at the tip. In addition, when the diameter is several tens of microns, the wire is easily bent, which makes it difficult to handle the element such as positioning.

Therefore, if a magnetic detection element utilizing the MI effect can be formed of a thin film, the thickness, width, and length can be freely selected on the substrate, which is considered to be suitable for a small element. However, the following points are necessary for thinning the device.

1) A MI effect higher than that of an amorphous wire can be obtained.

2) Static characteristics (high Q
Value).

Therefore, the object of the present invention is to satisfy this condition, to realize magnetic detection by the MI effect when the element body is made of a thin film, and which has higher performance and is easier to handle than an element made of amorphous wire. It is to provide an element.

[0013]

In order to solve the above problems, according to the present invention, there is provided a magnetic detection element utilizing the MI effect, wherein a substantially rectangular high permeability magnetic film is formed on a non-magnetic substrate. The high-permeability magnetic film is arranged so that the longitudinal direction is along the application direction of the external magnetic field to be detected, and the direction of the easy axis of magnetization is perpendicular to the longitudinal direction in the film plane. The magnetic anisotropy is added so that the high magnetic permeability magnetic film is applied with a high-frequency current from both longitudinal end portions thereof, and an impedance is generated between both longitudinal end portions of the high magnetic permeability magnetic film by an external magnetic field. A magnetic detecting element using the first structure, in which the change in is converted into an electric signal to obtain an output, and a MI effect, which is a substantially rectangular high transparent member on a non-magnetic substrate in order from the bottom. Constructed by stacking magnetic susceptibility magnetic film, insulating film, and conductive film The laminated layers of the respective films are arranged such that the longitudinal direction is along the application direction of the external magnetic field to be detected, and the high permeability magnetic film has a direction of easy magnetization axis perpendicular to the longitudinal direction in the film plane. Magnetic anisotropy is added so that a high-frequency current is applied to the conductive film from both ends in the longitudinal direction, and a change in impedance generated between both ends in the longitudinal direction of the conductive film by an external magnetic field is converted into an electric signal. A second configuration is adopted in which the output is obtained by conversion, and a third configuration in which an insulating film and a high-permeability magnetic film are further laminated on the conductive film of the second configuration is adopted.

Further, in each of the second and third configurations, the fourth and fifth configurations in which the insulating film is omitted are adopted because the electrical resistivity of the high-permeability magnetic film is significantly higher than that of the conductive film. .

[0015]

With any of the above configurations, the external magnetic field can be detected by utilizing the MI effect. Then, by selecting the longitudinal magnetic permeability and film thickness of the high magnetic permeability magnetic film material, or the film thickness of the insulating film and the conductive film, it is possible to obtain higher performance than that of an element composed of an amorphous wire. In addition, you can freely select the thickness, width, and length of each film,
Easy to handle and excellent in miniaturization.

In the first configuration, both the resistance component and the inductance component of the impedance change due to the external magnetic field,
In the second and third configurations, the inductance can be maintained and the resistance can be reduced. Also, in the third configuration, the second
Inductance can be increased by the above configuration.

Further, according to the fourth and fifth structures, the same operation as the second and third structures can be obtained with a simple structure without the insulating film.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 1 shows the structure of a first embodiment of a magnetic sensor utilizing the MI effect.

In the structure of the magnetic sensing element of this embodiment, the high magnetic permeability magnetic film 12 is formed on the entire upper surface of the elongated rectangular non-magnetic substrate 10, and a terminal is formed on each of both ends in the longitudinal direction. Conductive film 14 is formed, and conductive film 1
A wire 18 is connected to each of the four by solder 16 and is drawn out for external connection.

The non-magnetic substrate 10 is made of calcium titanate (Ti-Ca type ceramic), oxide glass, titania, alumina or the like.

In FIG. 1, an arrow Hex is a magnetic field detection direction in which an external magnetic field to be detected is applied to the magnetic detection element, and has a long magnetic permeability in the longitudinal direction of the nonmagnetic substrate 10, that is, a rectangular shape corresponding to the substrate 10. The magnetic film 12 is arranged so that its longitudinal direction is along the magnetic field detection direction. Further, in the magnetic film 12, the direction of the easy axis of magnetization is perpendicular to the longitudinal direction within the film surface of the magnetic film 12 as shown by the double-headed arrow in FIG. 1, that is, in the direction perpendicular to the magnetic field detection direction. Magnetic anisotropy is added so that

With this structure, a high-frequency drive current is applied to both ends of the magnetic film 12 in the longitudinal direction via the wire 18 and the conductive film 14 to generate an impedance between the both ends of the magnetic film 12 in the longitudinal direction by an external magnetic field. Is converted into an electric signal to obtain an output.

By the way, the magnetic permeability of the high magnetic permeability material forming the magnetic film 12 and the thickness thereof make it possible to determine the M of the magnetic sensing element.
The I characteristic is determined. The test performed to examine the material and the thickness and the result are described below.

First, in order to see the relationship between the magnetic permeability and the MI characteristic, a plurality of samples of the magnetic film 12 having different magnetic permeability in the longitudinal direction are prepared, and the magnetic permeability in the longitudinal direction at 1 MHz and M
The relationship with the I characteristic was investigated. Sample size is width W =
The maximum change amount of impedance was measured by changing the external magnetic field of about ± 10 Oe with a Helmholtz coil while applying 0.2 mm, thickness t = 5 μm and length L = 4 mm.

The results are shown in the graph of FIG. This figure 2
As is clear from the above, there is a correlation between the magnetic permeability in the longitudinal direction and the maximum impedance change amount. And the maximum change in impedance is 25%, which is equal to or higher than that of amorphous wire.
If a numerical value of (about 2 dB) or more is used as a guide, it can be seen from the graph that the magnetic permeability needs to be 2500 or more. In order to clear this numerical value, an Fe—Co—B-based amorphous film, which has a higher magnetic permeability than a magnetic film having a crystal structure such as Sendust, or a microcrystalline film such as an Fe—N-based or Fe—C-based magnetic film is used as the magnetic film 12.
Suitable for

Further, an Fe-Ta-C-based microcrystalline film was used, and MI characteristics depending on the film thickness were measured. The magnetic permeability in the longitudinal direction of the magnetic film is 4100 at 1 MHz. Three kinds of samples with film thicknesses of 2, 5 and 8 μm were prepared, and the external magnetic field was ± 10 Oe at a drive current of 100 MHz.
The amount of change in impedance was measured by varying the degree.

The results are shown in FIG. It can be seen from FIG. 3 that when the film thickness t is 5 μm, the peak value becomes lower at 2 μm, and at 8 μm, the peak spreads slightly outward, and the slope of change begins to become slightly gentle. The optimum range is 3 μm to 8 μm according to the test results, but it is not particularly limited as long as it is used outside the range as long as the peak height and the decrease in slope do not affect the usage.

As described above, the magnetic film 12 is an Fe-Co-B system amorphous film having a magnetic permeability in the longitudinal direction at 1 MHz of 2500 or more, or a microcrystalline film of Fe-N system, Fe-C system, etc. It is preferable that the thickness is 3 μm to 8 μm, and by doing so, it is possible to provide a small-sized and highly sensitive magnetic detection element that can obtain the MI effect more than that of the amorphous wire.

[Second Embodiment] In the first embodiment, both the resistance component and the inductance component of the impedance change due to the change of the magnetic permeability due to the external magnetic field as in the case of the amorphous wire. , It is better that there is no change in resistance.

Therefore, the second aspect of the present invention having such a configuration
An embodiment will be described with reference to FIG.

In the structure of the magnetic sensing element of the second embodiment shown in FIG. 4, a high magnetic permeability magnetic film 22 is formed on the entire upper surface of a rectangular non-magnetic substrate 20, and an insulating film 24 is laminated thereon. Further, a conductive film 26 is laminated on the above. Wires 28 for external connection are connected to the respective ends of the conductive film 26 in the longitudinal direction with solder 27 and drawn out. Further, as in the first embodiment, the entire longitudinal direction is arranged along the detection direction of the external magnetic field.

The details of each are as follows.
Is calcium titanate (Ti-C) as in the first embodiment.
a-based ceramic), oxide glass, titania, alumina, etc.

The magnetic film 22 is made of Fe--as described in the first embodiment.
Co-B system amorphous film or Fe-C system, Fe-
An N-based microcrystalline film or the like is formed by a vacuum film forming technique.
Similarly, the magnetic film 22 is provided with magnetic anisotropy so that the direction of the easy axis of magnetization is perpendicular to the longitudinal direction within the film surface of the magnetic film 22 as indicated by the double-headed arrow in FIG. . This anisotropy is imparted by cooling in a magnetic field after film formation.

The insulating film 24 is made of SiO ₂ , Cr ₂ O ₃ , Ti.
It is an oxide insulating film such as O ₂ and is formed by a vacuum film forming technique or the like. The lower limit of the thickness is 0.05 μm at which the insulating effect is obtained, and the upper limit is preferably 1 μm or less so that the inductance value generated between the conductive film 26 and the high-permeability magnetic film 22 does not become small.

Further, the conductive film 26 on the insulating film 24 is made of Cu,
It is made of a metal having a low specific resistance such as Au.

In such a structure, at the time of detection, a high frequency drive current is applied to the conductive film 26 from both ends in the longitudinal direction via the wire 28. Unlike the case where a current is directly applied to the magnetic film as in the first embodiment, the magnetic flux due to the drive current penetrates in the cross section of the magnetic film 22 without returning, but the direction of the magnetic flux is the magnetization of the magnetic film 22. Since it is along the easy axis direction, the mechanism for changing the inductance is not lost, and the change in impedance occurs between both ends of the conductive film 26 in the longitudinal direction due to the external magnetic field. As a matter of course,
Since no current is passed through the magnetic film 22, the influence of the skin effect due to the eddy current does not appear, and the resistance component hardly changes.

Actual data of the characteristics of the device of this example are shown below.

An Fe—Ta—C type microcrystalline magnetic film is used as the high permeability magnetic film, and the size is 5 μm thick and the width is 0.2 m.
m, length 4 mm, a sample of the first embodiment in which a drive current is directly applied to the magnetic film, and a Cu conductive film is formed on the magnetic film via an insulating film of Cr ₂ O _{3 having} a thickness of 0.1 μm. The samples of the second embodiment formed with a thickness of 1 μm were compared. As the measurement conditions, a drive current of 100 MHz was passed and the amount of change in impedance with respect to an external magnetic field was compared. The results are shown in Table 1 below.

[0040]

[Table 1]

As can be seen from the results in Table 1 above, a conductive film is provided on the magnetic film via an insulating film and a drive current is passed through the conductive film, so that the inductance L is maintained and the impedance variation ΔZ / Z. While maintaining the above, the resistance R can be significantly reduced, and a high Q value can be obtained.

Further, in this embodiment, the high magnetic permeability magnetic film 22 is used.
Since no drive current is applied to the magnetic film 22, there is no concern about leakage current from the magnetic film 22 to the outside, and there is no problem even if the magnetic film 22 contacts a magnetic recording medium or a magnetizing medium. do not need.

As a modification of the present embodiment, the magnetic film 2
If 2 is a laminated film in which a plurality of layers are alternately laminated with an insulating film, the effect of this embodiment can be further improved.

In the structure of this embodiment, if the electrical resistivity of the high-permeability magnetic film 22 is significantly higher than that of the conductive film 26, for example, 100 μΩ-cm or more, the insulating film 24 is unnecessary and can be omitted. . The conductive film 26 is, for example, Cu
In the case of, the specific resistance is 2 μΩ-cm. On the other hand, when the specific resistance of the high magnetic permeability magnetic film 22 is 100 μΩ-cm or more, the specific resistance of the high magnetic permeability magnetic film 22 is 50% of that of the conductive film 26.
When the drive current is applied to the conductive film 26, almost all of the drive current flows through the conductive film 26 without the insulating film 24 and only a very small amount flows into the high magnetic permeability magnetic film 22. Almost the same effect can be obtained.

[Third Embodiment] In the second embodiment, the conductive film 2 is used.
Inductance is formed by 6 and the high-permeability magnetic film 22. However, since the magnetic path of the magnetic film 22 is opened with respect to the magnetic field due to the drive current, the inductance is low and the circuit may be difficult to handle. The configuration of the third embodiment in consideration of that point is shown in FIG.

In the structure shown in FIG. 5, the high magnetic permeability magnetic film 22, the insulating film 24, and the conductive film 26 are laminated on the non-magnetic substrate 20 in this order from the bottom to form the same structure as that of the second embodiment. Further, an insulating film 24 'is formed on an intermediate portion except both ends where the wire 28 of the conductive film 26 is connected by the solder 27, and a high magnetic permeability magnetic film 22' is laminated on the insulating film 24 '. . Magnetic film 22 '
Similar to the magnetic film 22, has magnetic anisotropy so that the direction of the easy axis of magnetization is perpendicular to the longitudinal direction in the film plane.
Then, as in the first and second embodiments, the entire longitudinal direction is arranged along the detection direction of the external magnetic field.

In this structure, by forming the high-permeability magnetic films 22 and 22 'above and below the conductive film 26, the magnetic path of the magnetic body through which the magnetic flux due to the drive current application flows can be made a substantially closed magnetic path.

The thickness of the insulating films 24 and 24 'is set to 0.05 .mu.m to 1 .mu.m as in the second embodiment, but the conductive film 26 is used.
The total thickness of the upper and lower insulating films 24 and 24 'corresponds to the magnetic gap between the upper and lower two high-permeability magnetic films 22 and 22', and must be set as thin as possible to increase the inductance. , 0.2 μm to 3 μm is suitable.

Actual data on the characteristics of the device of this example are shown below.

Fe-- is used as the high-permeability magnetic films 22 and 22 '.
A Ta-C based microcrystalline magnetic film is used, and the size is 5 μm.
m, width 0.2 mm, length 3 m above the upper magnetic film 22 '
m, the lower magnetic film 22 is 4 mm, and the insulating films 24, 2
4'is made of Cr ₂ O ₃ and has a thickness of 0.1 μm, and the conductive film 26 is made of Cu and has a thickness of 0.5 μm to form the element of this embodiment. Table 2 below shows the results of examining the characteristics at a drive current of 100 MHz.

[0051]

[Table 2]

As can be seen from Table 2, according to the present embodiment, the inductance L is approximately doubled as compared with the second embodiment, the impedance change amount ΔZ / Z is increased, and the Q value is also increased.

In this embodiment as well, as in the second embodiment, the electrical resistivity of the high-permeability magnetic films 22 and 22 'is significantly higher than that of the conductive film 26, for example, 100 μΩ-cm or more, and the insulating film 24 is formed. , 24 'may be omitted.

Further, as a modification of this embodiment, as shown in FIG. 6, the width Wr in the direction perpendicular to the longitudinal direction in the film surface of the conductive film 26 is set to the same direction as the high magnetic permeability magnetic films 22 and 22 '. Width Wm
If it is made smaller, the width Wm of the upper and lower magnetic films 22, 22 '
Both ends in the direction are closer to each other, and the magnetic films 22 and 22 'form a closed magnetic path that is closer to perfection, and the inductance can be further improved. Here, as described above, the insulating films 24, 2
If 4'is omitted, the magnetic films 22 and 22 'form a complete closed magnetic path, and the inductance can be improved.

Further, in this embodiment as well, if the magnetic films 22 and 22 'are laminated by alternately laminating a plurality of layers with the insulating films, the effect can be further improved.

[0056]

As is apparent from the above description, according to the present invention, a first structure in which a substantially rectangular high-permeability magnetic film is formed on a non-magnetic substrate, and a substantially rectangular high magnetic film is formed in order from the bottom. A second structure in which a magnetic permeability film, an insulating film, and a conductive film are laminated,
Furthermore, in the third structure in which an insulating film and a high-permeability magnetic film are laminated on the conductive film, or in the second and third structures, the electrical resistivity of the high-permeability magnetic film is significantly higher than that of the conductive film. With the fourth and fifth configurations in which the insulating film is omitted, the MI
It is possible to perform magnetic detection utilizing the effect, and it is possible to obtain higher performance than an element composed of an amorphous wire by selecting the material and film thickness of each film. In addition, the film thickness, width, and length of each film can be freely selected, easy handling, and suitable for miniaturization.

Further, in the first configuration, both the resistance component and the inductance component of the impedance are changed by the external magnetic field, but in the second and third configurations, the inductance component can be maintained and the resistance component can be lowered. Furthermore, the third configuration can increase the inductance more than the second configuration.
In addition, in the fourth and fifth configurations, an excellent effect such as an effect similar to that of the second and third configurations can be obtained by a simple configuration in which the insulating film is omitted.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a first embodiment of a magnetic sensor according to the present invention.

FIG. 2 is a graph showing the relationship between the magnetic permeability of the high-permeability magnetic film of the example and the maximum change amount of impedance.

FIG. 3 is a graph showing the relationship between the film thickness of the high magnetic permeability magnetic film and the amount of impedance change of the same example.

FIG. 4 is a perspective view showing a structure of a second embodiment.

FIG. 5 is a perspective view showing the structure of the third embodiment.

FIG. 6 is a perspective view showing the structure of a modified example of the third embodiment.

FIG. 7 is a circuit diagram of a Colpitts oscillator circuit.

FIG. 8 is a circuit diagram of a multivibrator type oscillation circuit.

[Explanation of symbols]

 10,20 Non-magnetic substrate 12,22,22 'High permeability magnetic film 14,26 Conductive film 16,27 Solder 18,28 Wire 24,24' Insulating film

Claims (12)

[Claims] 1. A magnetic sensing element utilizing a magneto-impedance effect, comprising a substantially rectangular high-permeability magnetic film formed on a non-magnetic substrate, wherein the high-permeability magnetic film has a longitudinal direction. It is arranged along the direction of application of the external magnetic field to be detected, and has magnetic anisotropy so that the direction of the easy axis of magnetization is perpendicular to the longitudinal direction in the film plane, and the high magnetic permeability A high-frequency current is applied to both ends of the magnetic film in the longitudinal direction to convert an impedance change generated between both ends of the high-permeability magnetic film by an external magnetic field into an electric signal to obtain an output. Magnetic sensing element characterized by. 2. The magnetic sensing element according to claim 1, wherein the magnetic permeability in the longitudinal direction of the high-permeability magnetic film at 1 MHz is 2500 or more. 3. The high-permeability magnetic film has a thickness of 3 μm to 8 μm.
It is within the range of μm.
The magnetic detection element according to 1. 4. A magnetic detection element utilizing a magneto-impedance effect, comprising a non-magnetic substrate and a substantially rectangular high-permeability magnetic film, an insulating film, and a conductive film, which are laminated in this order from the bottom. The lamination of each film is arranged such that the longitudinal direction is along the direction of application of the external magnetic field to be detected, and the high permeability magnetic film is such that the direction of the easy axis of magnetization is the direction perpendicular to the longitudinal direction in the film plane. Magnetic anisotropy is added, and a high-frequency current is applied to the conductive film from both ends in the longitudinal direction to convert an impedance change generated between both ends in the longitudinal direction of the conductive film into an electric signal by an external magnetic field. A magnetic detection element characterized in that an output is obtained. 5. A magnetic detection element utilizing a magneto-impedance effect, comprising a non-magnetic substrate and a substantially rectangular high magnetic permeability film, an insulating film, a conductive film, an insulating film, and a high magnetic permeability magnetic film, each having a substantially rectangular shape in order from the bottom. The layers of the films are arranged such that the longitudinal direction is along the direction of application of the external magnetic field to be detected, and the high-permeability magnetic films each have an easy axis of magnetization in the film plane. Magnetic anisotropy is imparted to the film in a direction perpendicular to the longitudinal direction, and a high-frequency current is applied to the conductive film from both ends in the longitudinal direction to generate a magnetic field between both ends in the longitudinal direction of the conductive film by an external magnetic field. A magnetic detection element characterized in that a change in impedance is converted into an electric signal so that an output can be obtained. 6. The insulating film has a thickness of 0.05 μm to 1 μm.
The magnetic detection element according to claim 4 or 5, wherein m is m. 7. The magnetic sensing element according to claim 4, wherein the high-permeability magnetic film is a laminated film in which a plurality of layers are alternately laminated with an insulating film. 8. An inner insulating film laminated in order from the bottom,
The magnetic detection element according to claim 5, wherein the total thickness of the conductive film and the insulating film is 0.2 µm to 3 µm. 9. A magnetic sensing element using a magneto-impedance effect, comprising a non-magnetic substrate and a rectangular high-permeability magnetic film and a conductive film, which are laminated in this order from the bottom, respectively. The lamination of the magnetic film and the conductive film is arranged such that the longitudinal direction is along the direction of application of the external magnetic field to be detected, and the high permeability magnetic film has a significantly higher electrical resistivity than the conductive film and an easy magnetization axis. Magnetic anisotropy is applied so that the direction of is perpendicular to the longitudinal direction in the film plane, and a high-frequency current is applied to the conductive film from both ends in the longitudinal direction, and the longitudinal direction of the conductive film is increased by an external magnetic field. A magnetic detection element, characterized in that a change in impedance occurring between both ends in a direction is converted into an electric signal to obtain an output. 10. A magnetic detection element utilizing a magneto-impedance effect, comprising a high magnetic permeability magnetic film, a conductive film, and a high magnetic permeability magnetic film, which are substantially rectangular and are stacked in order from the bottom on a non-magnetic substrate. The stacked layers of the respective films are arranged such that the longitudinal direction is along the direction of application of the external magnetic field to be detected, and the high magnetic permeability magnetic film has a significantly higher electric resistivity than the conductive film and is easy to magnetize. Magnetic anisotropy is provided so that the direction of the axis is perpendicular to the longitudinal direction in the film surface, and a high-frequency current is applied to the conductive film from both ends in the longitudinal direction to apply an external magnetic field to the conductive film. A magnetic detection element characterized in that a change in impedance occurring between both ends in the longitudinal direction is converted into an electric signal so that an output can be obtained. 11. The electrical resistivity of the high-permeability magnetic film is 1
The magnetic detection element according to claim 9 or 10, wherein the magnetic detection element has a resistance of 00 µΩ-cm or more. 12. The width of the conductive film in the direction perpendicular to the longitudinal direction in the film plane is smaller than the width of the high magnetic permeability magnetic film in the same direction, according to claim 5, 8, or 10. The magnetic detection element described.