JPH0423413A - Soft magnetic thin film, its manufacturing method, and magnetic head - Google Patents

Abstract

PURPOSE:To provide an excellent soft magnetic characteristic, thermal stabilization and highly saturated flux density by specifying the composition of a soft magnetic alloy metal film which is Fe-based and contains N and one or more elements of groups IV to IIVa. CONSTITUTION:The title soft magnetic thin film is Fe-based and contains N by 1 to 20 atomic %. In is also provided with one or more elements of a group consisting of Ti, Zr and Hf of group IIVa elements. V, Nb and Ta of group Va elements, Cr, Mo, and W of group IVa elements, and Mn of group VIIa by 3 to 30 atomic %. This construction makes it possible to provide excellent abrasion resistance, and corrosion resistance and further supply a soft magnetic thin film made of an Fe-based single layer nitride alloy which is provided with excellent soft magnetic characteristics, their thermal stability and a highly saturated magnetic flux density.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a soft magnetic thin film used in a magnetic head, etc. in a magnetic recording and reproducing device such as a magnetic recording and reproducing device (VTR) and a magnetic recording and reproducing device, a method for manufacturing the same, and a method for manufacturing the soft magnetic thin film. It is related to the head.

2. Description of the Related Art In response to the recent demand for higher density recording in the field of magnetic recording, development of high-performance magnetic heads compatible with high coercive force media is progressing. The characteristics of a magnetic head are closely related to the material characteristics of the core material used in it, and in order to improve the performance of the magnetic head, we have developed excellent soft magnetic properties that have high saturation magnetic flux density and are thermally stable. There is a demand for a high-performance soft magnetic thin film that has excellent corrosion resistance and wear resistance.

In response to these requirements, the saturation magnetic flux density of ferrite is approximately 0.57. Permalloy, Sendust, C.

Even amorphous materials have a low saturation magnetic flux density of around IT, and these conventional materials have a limit to their saturation magnetic flux density.

On the other hand, Fe-3i/Ni-Fe, Fe-C/Ni-Fe
, Fe5in□, Fe-AI-N/5i-N, etc., a multilayer film in which tens to hundreds of different types of magnetic films or non-magnetic films are alternately laminated has a high saturation magnetic flux density. It is also known to exhibit thermally stable and good soft magnetic properties. It is believed that the high saturation magnetic flux density and excellent soft magnetic properties of these multilayer films are due to the fine crystal grain structure mainly composed of Fe.

However, when using these multilayer films as magnetic head core materials, it is necessary to alternately laminate tens to hundreds of ultrathin films of different types to form a total film thickness of several micrometers to several tens of micrometers, so the film formation process Moreover, since each layer is an extremely thin film of a different type, it is difficult to control the film thickness, and the film formation rate cannot be increased, which poses problems in mass production.

Recently, various efforts have been made to achieve soft magnetism with high saturation magnetic flux density and excellent thermal stability by refining crystal grains in a single-layer film, rather than using multilayers, which pose problems in mass production. Research has begun to be conducted. As one of them, Fe--N films are being researched. However, it is known that the soft magnetic properties of this Fe-N film are rapidly deteriorated by heat treatment at 350° C. or higher, and that there is a problem in the thermal stability of the soft magnetic properties. Therefore, this F
In an attempt to improve the thermal stability of the e-N film, a trace amount of N was added.
A film in which a trace amount of 1 atomic % of Zr and Ti is added to an Fe-N film (13th Japanese Society of Applied Magnetics, Abstracts of Academic Lectures 24)
pF-2 (1989)) has been studied.

However, the problem to be solved by the invention is that when a trace amount of Zr or T of about 1 atomic % as mentioned above
When a Fe-N film doped with i and a trace amount of N is used as a magnetic head core material, the content of Zr, Ti, and N elements, which are effective in corrosion resistance and wear resistance, is extremely small in the film. If this magnetic head is used as a magnetic head for a high-quality VTR or the like that has a high relative speed with a magnetic recording medium, and a magnetic recording medium that has strong abrasiveness with respect to the magnetic head is used in this VTR, the soft magnetic Abrasion resistance of thin films,
Also, problems arise in corrosion resistance when used under high humidity conditions.

Furthermore, with the recent remarkable progress in high-density recording, there is a demand for soft magnetic thin films having even better soft magnetic properties as magnetic head core materials. From this point of view, the above-mentioned Fe-N film doped with trace amounts of Zr, Ti, and trace amounts of N on the order of 1 atomic % is insufficient in terms of soft magnetic properties and has problems with thermal stability. There is.

Therefore, there is a demand for the development of high-performance soft magnetic thin films that are even more excellent in wear resistance, corrosion resistance, and soft magnetic properties. In addition, we can produce such soft magnetic thin films with good reproducibility and mass production.
There is a need for an appropriate manufacturing method for manufacturing with high productivity, and for a magnetic head using the above-mentioned high-performance soft magnetic thin film as a magnetic head core material.

The present invention was made in order to solve the above-mentioned problems, and has an iron-based material that has excellent wear resistance and corrosion resistance, as well as excellent soft magnetic properties, thermal stability, and high saturation magnetic flux density. The present invention aims to provide a soft magnetic thin film made of a single-layer nitride alloy, an appropriate manufacturing method for manufacturing such a soft magnetic thin film with high productivity, and a magnetic head using the soft magnetic thin film as a magnetic head core material. be.

Means for Solving the Problem The present inventor focused on the high saturation magnetic flux density of Fe and the excellent wear resistance and corrosion resistance peculiar to nitrides, and created a material that has a high saturation magnetic flux density, excellent soft magnetic properties, and In order to develop a high-performance soft magnetic thin film with excellent thermal stability, corrosion resistance, and wear resistance, the main component is Fe, contains N, and I
Va group elements Ti, Zr, Hf, Va group elements V, Nb
, Ta, CrXMo of group VIa elements, , W, and ■ Mn of group A elements. As a result of extensive research on alloy thin films containing one or more elements in the group, the composition of the alloy thin film was identified. The inventors have discovered the fact that excellent soft magnetic properties (low coercive force, high magnetic permeability) are exhibited when the magnetic flux is within the range of . In particular, it mainly contains Fe, contains N, Zr, and also contains Ti, Nb, Ta, and C.
A soft magnetic alloy thin film containing at least one element of the r element has excellent soft magnetic properties, thermal stability, low magnetostriction, and high saturation magnetic flux density in a specific composition range, and also has The discovery of the fact that it has both excellent wear resistance and corrosion resistance led to the invention of claim (2).

The method for manufacturing a soft magnetic thin film according to the invention of claim (3) is based on a sputtering method which has the advantage that although the film formation rate is slow, the equipment is inexpensive and the composition of the film can be easily controlled. Fifth
As shown in the figure, a magnetic head (referred to as an M I G head) has a magnetic path mostly composed of ferrite 17 and a soft magnetic thin film 19 provided only in the vicinity of the gear knob 18, which is likely to be magnetically saturated. It is suitable for forming a soft magnetic thin film with a relatively thin film thickness (several micrometers or less), such as the following. The sputtering method is a reactive bath-lid method in which N2 gas is mixed into Ar gas, or a sputtering method using nitride as a target, and sputtering using two-pole, three-pole, or magnetron methods using direct current or high frequency. method, bias sputtering method, and ion beam sputtering method.

The method for manufacturing a soft magnetic thin film according to the invention of claim (4) is based on an electron beam evaporation method which has a faster film formation rate and can handle a larger batch throughput than a sputtering method. As shown in FIG. 6, a soft magnetic thin film 21 is sandwiched between a nonmagnetic substrate 20 and a magnetic path is formed by the soft magnetic thin film 21, such as a bulk thin film type magnetic head. (
It is suitable for forming a large amount of soft magnetic thin films (several μm to several tens of μm).

The magnetic head according to the invention of claim (5) has high reliability,
In order to achieve high-density recording, the soft magnetic thin film of the present invention, which has a high saturation magnetic flux density, excellent soft magnetic properties, and excellent corrosion resistance and wear resistance, is used as a magnetic head core material.

According to the structure of the invention of operation claim (1), the main component is Fe, contains N, and contains IVaVa group elements i, Zr, Hf,
Va group elements V, Nb, Ta, Via group elements Cr, M
o, W, ■ One or two types in the Mn group of group a elements
Since the composition of the soft magnetic alloy thin film containing more than one element is within a specific range, the soft magnetic thin film has excellent soft magnetic properties, thermal stability, and high saturation magnetic flux density. At the same time, it can also have excellent wear resistance and corrosion resistance.

In particular, according to the structure of the invention of claim (2), the main component is Fe, and contains N, Zr, Ti, Nb, Ta,
Since it is a soft magnetic alloy thin film with a specific composition range containing at least one element of Cr, it has excellent soft magnetic properties, low magnetostriction, and high saturation magnetic flux density, as well as excellent wear resistance and corrosion resistance. It is possible to have both.

According to the structure of the invention of claim (3), since the apparatus is inexpensive and uses the sputtering method, which allows easy control of the film composition, it is possible to produce a soft magnetic thin film with a relatively thin film thickness (several μm or less) in small quantities. Increase productivity when

According to the structure of the invention of claim (4), since the film is formed by the electron beam evaporation method, which has a faster film formation speed than the sub-lid method and can achieve a larger patch throughput, the film can be formed with a relatively thick film thickness (several μm to Improves productivity when forming soft magnetic thin films in large quantities (several tens of μm).

According to the structure of the invention of claim (5), it has a high saturation magnetic flux density, excellent soft magnetic properties and thermal stability, and
Since the magnetic head uses the soft magnetic thin film, which has both excellent wear resistance and corrosion resistance, as the magnetic head core material, high-density recording can be achieved with a highly reliable magnetic head.

Examples Example 1 Using a FeZr target, introducing N2 gas into Ar gas and reactive sputtering at a N2 partial pressure of 2.5%, film compositions of Nos. 4 to 4 in Table 1 were prepared. Film thickness 2 with
Soft magnetic thin films with a thickness of μm were formed, and these soft magnetic thin films were heat-treated in a rotating magnetic field in a vacuum at a temperature of 200 to 550° C. for 1 hour. The coercive force Hc and saturation magnetic flux density Bs of these soft magnetic thin films after heat treatment at 500°C were measured and plotted against the Zr content in the film. As shown in Figure 1, the coercive force He was It decreases as the Zr content increases and reaches 0.20Q in the range of about 9 to 12 at% Zr content.
Below (effective magnetic permeability 4000 or more at I MHz)
It shows excellent soft magnetic properties of 0.80% even with a Zr content of about 7 at%. It shows a low coercive force. The saturation magnetic flux density Bs is
It shows a high value of 1.7T or more up to a Zr content of about 9 at%, and shows a value of about 1.6T even at a Zr content of about 12 at%, but the Fe content decreases when the Zr content is about 30 at% or higher. However, the saturation magnetic flux density decreased, making it less desirable.

Table 1 No. 1 in Table 1 above (film composition Fe88 at%, Zr7
atomic%, N5 atomic%, hereinafter referred to as FeaeZ r7Zs), NO,2 (F esbz rq Zs)
FIG. 2 shows the change in the coercive force Hc with respect to the heat treatment temperature of the soft magnetic thin films No. 3 (Fee+Zrl□Z5). From the figure, it was found that all soft magnetic thin films showed a constant coercive force Hc at a heat treatment temperature of 400° C. or higher, indicating that the soft magnetic properties of the films were excellent in thermal stability.

Next, by the same reactive sputtering method, N2 partial pressure 0.5
A Fe-Zr-N film with a thickness of 2 μm was formed in the range of 10%. Table 2 shows the film compositions of these soft magnetic thin films and the measurement results of the coercive force Hc after heat treatment in vacuum and in a rotating magnetic field. As shown in Table 2, the N content in the film is 1 to 20 atomic%.
, it was confirmed that good coercive force Hc was exhibited in the range of Zr content of 3 atomic % or more.

Table 2 Although the Fe-Zr-N film has been described in this embodiment, other films containing Fe as the main component and 1 to 2 at % of N, as well as Na group elements Ti, Zr, and Hf.

Va group elements V, Nb, Ta, VIa group elements Cr, M
o, W, ■ One or two types in the Mn group of group a elements
A soft magnetic thin film made of an iron-based single-layer nitride alloy having a composition containing 3 to 30 at.

Next, using FeZrNb and FeZrTa targets, a similar reactive sputtering method was applied to reduce the N2 partial pressure to 2.
Fe-Zr-Nb-N film with a film thickness of 2 μm at 5%, and Fe
-A Zr-Ta-N film was formed. These soft magnetic thin films were heated in a rotating magnetic field in a vacuum at a temperature of 200 to 550°C.
Heat treatment was performed for an hour. Table 3 shows the results of measuring the coercive force Hc, effective magnetic permeability μ8 at IMHz, and saturation magnetic flux density Bs of these soft magnetic thin films after heat treatment at 550°C. As shown in Table 3, the Fe-Zr-Nb-N film and the F'e-Zr-Ta-N film have excellent soft magnetic properties (low coercive force, high magnetic permeability) and high saturation magnetic flux density. It was found that it has. In addition, as a result of measuring the saturation magnetostriction λ of these soft magnetic thin films, F e eo, s Z r I
oNq, the value of saturation magnetostriction λ3 is 172 compared to the s film.
Fe-ZrNb-N film and Fe
It was found that the saturation magnetostriction of the -Zr-Ta-N film exhibits a smaller value than that of the Fe-Zr-N film. This means that F
The e-Zr-Nb-N film and the FeZr-Ta-N film are
This shows that the deterioration of soft magnetic properties is small due to stress during processing into a magnetic head and gap formation, making it preferable as a magnetic head core material.

Table 3 As a result of examining the change in coercive force Hc with respect to heat treatment temperature of the soft magnetic thin films shown in Table 3, the coercive force Hc of all soft magnetic thin films showed a constant value at heat treatment temperature of 400°C or higher.
The soft magnetic properties of the film were found to have excellent thermal stability.

Note that in this example, Fe-Zr-Nb-N film and Fe
- Although the Zr-Ta-N film was explained, other F films other than the above
It has a composition containing e as a main component, 1 to 20 at% of N, 3 to 20 at% of Zr, and 0.5 to 10 at% of at least one of the elements Nb, Tj, Ta, and Cr. A soft magnetic thin film made of an iron-based single-layer nitride alloy has a similar effect.

Furthermore, the sputtering method is not limited to the reactive sputtering method in which N2 gas is mixed into Ar gas, but also the sputtering method using nitride as a target, bipolar sputtering, triode sputtering, and magnetron sputtering using direct current or high frequency. Similar effects can be obtained in the method, bias sputtering method, and ion beam sputtering method.

Next, a wear resistance test was conducted on the soft magnetic thin film made of the above-mentioned iron-based single-layer nitride alloy. The results are shown in Table 4. In this test, Fe-
A relative comparison was made of the amount of wear with the N film (FeqsZrrNz). During the test, as shown in FIG.
A soft magnetic thin film 15 made of the iron-based nitride alloy is formed on the curved surface 14a.
was formed to produce a dummy head 16. Then, a metal tape is slid onto the surface of the iron-based single-layer nitride alloy film 15,
The wear amount of the iron-based single-layer nitride alloy film 15 was measured. The amount of wear was determined by reading the length of the diagonal line of the micro Vickers indentation made on the surface of the iron-based single-layer nitride alloy film 15, that is, the sliding contact surface with the metal tape.

From the results shown in Table 4, the wear resistance improves as the N or Zr content increases. Also, Nb, Ti, Ta, C
By containing at least one element of the r element,
Furthermore, wear resistance is improved.

The above example shows the case where Nb, Ti, Ta, and Cr elements are used alone, but even if multiple types of the above elements are contained at 0.5 to 10 atomic % at the same time, the wear resistance will be the same. can improve sexual performance.

Next, the results of a corrosion resistance test performed on the soft magnetic thin film made of the above-mentioned iron-based single-layer nitride alloy are shown below. In this test, the specimen was immersed in a 5% NaCl aqueous solution for 24 hours at room temperature, and the state of corrosion was examined. Fe7. .

The Zr1N3 and Feq7Ti+Nz films had dot-like corrosion, but they were mainly composed of Fe, containing 1 to 20 at% of N, 3 to 20 at% of Zr, and at least one of the elements Nb, Ti, Ta, and Cr. Corrosion did not occur in any of the iron-based single-layer nitride alloy films having a composition containing 0.5 to 10 at% of the elements. From this result, it was found that the iron-based single-layer nitride alloy film had improved corrosion resistance.

In addition, je other than the above is the main component, and N is 1 to 20 atomic%.
Contains IVaVa group elements i, Zr, Hf,
V, Nb, Ta, which is a Va group element, and Cr, which is a VIa group element.

Similarly, a soft magnetic thin film made of an iron-based single-layer nitride alloy having a composition containing 3 to 30 atomic percent of one or more elements in the Mn group of group A elements such as Mo, W, and ■Mn of Group A elements also exhibits corrosion resistance and wear resistance. It has an improving effect.

Example 2 A soft magnetic thin film according to the present invention contains Fe as a main component and N as a main component.
Contains 20 atom% and rVaVa group elements i, Zr, H
f, V of the Va group element, Nb, Ta, Cr of the VIa group element
, Mo, W, and 3 to 30 atomic % of one or more elements in the group of Mn of group a elements.

In particular, Fe is the main component, N is 1 to 20 atomic %, and Zr is 3 atomic %.
It is a soft magnetic thin film made of an iron-based single-layer nitride alloy having a composition containing ~20 at% and at least 0.5 to 10 at% of at least one of the elements Nb, Ti, Ta, and Cr.

The above soft magnetic thin film was formed to a thickness of 2 μm using an electron beam evaporation apparatus combined with an ion gun as shown in FIG. This will be explained below based on FIG.

In the upper part of a vacuum belljar 1 serving as a vacuum container, a plurality of substrates 2 made of crystallized glass or ceramics, on which vapor deposition films are formed, are arranged in parallel on a curved substrate holder 3 with the vapor deposition surfaces facing downward. There is. Further, the substrate holder 3 is provided with a shaft 4 linked to a motor for rotating the substrate holder 3, and the substrate holder 3 rotates around the shaft 4. In the lower part of the vacuum belljar 1, electron beam generating filaments 5 and 6 as electron guns are arranged in symmetrical positions on the left and right, and the electron beam 5 generated from each electron beam generating filament 5 and 6 is
Crucibles 7 and 8 corresponding to each filament 5 and 6 are arranged symmetrically between the irradiation positions a and 6a, that is, between the electron beam generating filaments 5 and 6. Iron 9 as an evaporation source material is placed in one crucible 7, and evaporation source material 10 other than iron is placed in the other crucible 8. The evaporation source material 10 includes IVaVa group elements i, Zr, Hf.

Va group elements V, Nb, Ta, Vla group elements Cr, M
OlW, ■ 1 or 2 in the Mn group of group a elements
It consists of an alloy ingot made by melting more than one element in a high-frequency melting furnace.

Further, a shutter which can be opened and closed between the substrate holder 3 and the crucibles 7 and 8 in the vacuum belljar 1 prevents the vapor of the evaporation source materials 9 and 10 from reaching the substrate 2 during the closing operation. 11 are provided. In addition, an ion gun 12 is installed on the inside surface of the vacuum bell gear 1.
Nitrogen gas is introduced to create a nitrogen ion beam 13.

In the above configuration, when the electron beam evaporation apparatus operates, electron beams 5a and 6a are generated from the electron beam generating filament 5.6, and these electron beams 5a and 6a are transmitted to the evaporation source material 9 disposed in the crucible 7.8. , 10. At this time, the shutter 11 is open. When irradiated with the electron beams 5a and 6a, the evaporation source materials 9 and 10 turn into vapor. This vapor becomes a vapor flow and reaches the substrate 2.
adheres to the surface of At this time, the nitrogen ion beam 13 emitted by the ion gun 12 also reaches the substrate 2, forming a soft magnetic thin film made of an iron-based single-layer nitride alloy.

The soft magnetic thin film produced in this example is as follows: Example 1
It was confirmed that it had the same effect.

In this embodiment, the electron beam generating filaments 5 and 6 are provided individually corresponding to the evaporation source materials 9 and 10, but only one electron beam generating filament 5 and 6 is provided. It is also possible to adopt a method in which the evaporation source materials 9 and 10 are alternately irradiated with electron beams generated from this one filament at minute time intervals.

Example 3 The soft magnetic thin film 19 portion of the magnetic head (MIG head) having the structure shown in FIG. A MIG head was fabricated using the soft magnetic thin film. The thickness of the soft magnetic thin film made of the iron-based single-layer nitride alloy (see Figure 5)
M) were each 5 μm, the gap length was 0.15 μm, the track width was 5 μm, the gap depth was 20 μm, and the number of turns of the coil was 22 turns. For comparison, an MIG head with the same structure as described above was fabricated using a Sendust film with a saturation magnetic flux density of 1.1T for the soft magnetic thin film 19 portion, and a Co-Cr
Single layer media (thickness 0.2 μm, Hc (±) -1300
0e, Hk=5KOe), the recording and reproducing characteristics were investigated. This was done by self-recording and replaying at a circumferential speed of 3 m/sec. As a result, the magnetic head using the soft magnetic thin film made of the iron-based single-layer nitride alloy of the present invention as the magnetic head core material has a magnetic head that uses Sendust film as the magnetic head core material, about 3
An increase in playback output of dB was obtained.

Effects of the Invention According to the invention of claim (1), it is possible to provide a soft magnetic thin film that has excellent thermally stable soft magnetic properties and high saturation magnetic flux density, as well as excellent wear resistance and corrosion resistance. A magnetic head using the soft magnetic thin film of the present invention can be used, for example, in a high-quality VTR that slides at a high relative speed with a magnetic recording medium.
It is suitable for

According to the invention of claim (2), it has better soft magnetic properties, lower magnetostriction, and higher saturation magnetic flux density than the soft magnetic thin film according to the invention of claim (1), and also has excellent wear resistance.
A soft magnetic thin film that also has corrosion resistance can be provided.

According to the invention of claim (3), the film thickness is relatively thin (several μm).
Productivity can be increased when producing small quantities of soft magnetic thin films as described below.

According to the invention of claim (4), the film thickness is relatively thick (several 71
Productivity can be increased when forming a large number of soft magnetic thin films with a thickness of 100 μm to several tens of μm.

According to the invention of claim (5), a magnetic head using a soft magnetic thin film having excellent thermally stable soft magnetic properties and high saturation magnetic flux density as well as excellent wear resistance and corrosion resistance is used as the magnetic head core material. Since it is a magnetic head, it is possible to achieve high-density recording with a highly reliable magnetic head.

[Brief explanation of the drawing]

Figure 1 shows the coercive force Hc and saturation magnetic flux density Bs with respect to the Zr content in the soft magnetic thin film prepared in one embodiment of the present invention.
FIG. 2 is a diagram showing the change in coercive force Hc with respect to the heat treatment temperature of the soft magnetic thin film prepared in the example of the present invention, and FIG. FIG. 4 is a perspective view showing a dummy head for measuring wear resistance, and FIGS. 5 and 6 are schematic diagrams of conventionally provided magnetic heads. ■...Vacuum bell jar, 2...Substrate, 3
......Substrate boulder-14...Shaft,
5, 6... Filament for electron beam generation (electron gun), 7.8... Crucible, 9... Iron as evaporation source material, 10... - Evaporation source material other than iron, 11... Shutter, 12... Ion gun, 13... Nitrogen ion beam, 14.
... Substrate, 15 ... Soft magnetic thin film, 16.
... Dummy head, 17 ... Ferrite, 18 ... Gap, 19 ... Soft magnetic thin film, 20 ... Nonmagnetic substrate, 21 ...・・・・・・
Soft magnetic thin film, 22.23...Glass. Name of agent: Patent attorney Shigetaka Awano

Claims (5)

[Claims] (1) Contains Fe as the main component and 1 to 20 atomic% of N, as well as IVa group elements Ti, Zr, Hf, Va group elements V,
Nb, Ta, group VIa elements Cr, Mo, W, VIIa
1. A soft magnetic thin film made of an iron-based single-layer nitride alloy, characterized in that it has a composition containing 3 to 30 atomic % of one or more elements in the Mn group. (2) Fe is the main component, N is 1 to 20 atomic%, and Zr is 3
1. A soft magnetic thin film made of an iron-based single-layer nitride alloy, characterized by having a composition containing ~20 at.% and at least 0.5-10 at.% of at least one of Ti, Nb, Ta, and Cr elements. (3) A method for manufacturing a soft magnetic thin film made of an iron-based single-layer nitride alloy, characterized in that the soft magnetic thin film according to any one of claims (1) or (2) is formed by a sputtering method. (4) A method for manufacturing a soft magnetic thin film made of an iron-based single-layer nitride alloy, characterized in that the soft magnetic thin film according to any one of claims (1) or (2) is formed by an electron beam evaporation method. (5) A magnetic head characterized in that the soft magnetic thin film according to claim 1 or 2 is used as a magnetic head core material.