JPH10270246A - Magnetic thin film - Google Patents

Abstract

(57) [Abstract] [Object] The present invention provides an anisotropic magnetic field of 20 Oe or more, an electric resistivity of 50 μΩcm or more, and a saturation magnetic flux density of 16 k.
It is an object of the present invention to provide a magnetic film exhibiting excellent soft magnetism in a high frequency band having G or more. [Configuration] formula _{Co 100-X-Y-Z} Fe X M Y O Z
(Atomic%), and the respective atomic ratios are 10 <X <502 2 <Y <10 6 <Z <25 15 <X + Y + Z <65, and M is A where the heat of formation of the oxide is -1000 kJ or more.
1, Zr, Ti, Hf, Mg, Be, or one or more of the rare earth elements, having an anisotropic magnetic field of 20 Oe or more, an electric resistivity of 50 μΩcm or more, and a saturation magnetic flux density of 16 kG. A magnetic thin film having the above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film having high saturation magnetization, uniaxial magnetic anisotropy and electric resistivity and exhibiting excellent soft magnetism in a high frequency band.

[0002]

2. Description of the Related Art With the recent increase in the speed and recording density of computers and the development of mobile communications, efforts have been made to increase the operating frequency of electronic devices and to reduce the size of electronic devices accordingly. This tendency extends to the magnetic devices used therein, and the development of magnetic materials therefor has been studied, but none having sufficient properties has yet been found. In particular, it is conceivable that the recording head material of a hard disk drive device for ultra-high density recording in the near future will be a major problem.

Generally, in the high frequency band of 1 MHz or higher, eddy currents increase due to the low electrical resistance of metallic magnetic materials, making it difficult to use in the high frequency band. Therefore, an oxide magnetic material represented by a soft magnetic ferrite or the like has been conventionally used as a high-frequency soft magnetic material. Ferrite has a very high electric resistance of the material itself, so that loss due to eddy current is small. However, since the ferrite has a small saturation magnetization, the resonance frequency of the magnetic permeability is not so high, and abnormal resonance is observed in a low frequency band.
Further, since the magnitude of the magnetic permeability is not so large, there are many restrictions on its use. The biggest and fatal drawback of ferrite in microfabrication of magnetic devices is that thinning is not possible at present.

The expectation for a magnetic material having a large saturation magnetization (Bs) and exhibiting an excellent frequency dependence of magnetic permeability up to a high frequency band is particularly demanded in the field of a magnetic head for high density recording and a micro transformer material in a high frequency band. And a large number of magnetic materials such as Fe-Hf-C
(Hasegawa, Saito: IEICE Technical Report: MR
89-12 (1989)) and Fe-Ta-N (Nago, Sakakima, Ihara: Journal of the Japan Society of Applied Magnetics, 15, 365)
(1991)) and other Fe-based microcrystalline soft magnetic films have been proposed. Since these materials have a large Bs, they are excellent in overwrite characteristics in, for example, a recording magnetic head and can sufficiently cope with the current writing speed. However, in recent years, the recording density of the hard disk is increasing at a rate of 40% per year. In the recording system of a higher recording density several years later, the speed of the hard disk becomes close to 100 MHz as the recording density increases. In addition, it is conceivable that the current soft magnetic material cannot be used. For this reason, a magnetic material exhibiting excellent saturation magnetization and excellent frequency dependence of magnetic permeability up to a higher frequency band is expected.

[0005]

It is considered that a strong demand for a higher density of the recording capacity of the hard disk and a micro magnetic device operating at a high frequency will be further increased in the future. For example, considering a large-capacity, ultra-high-speed magnetic recording system in terms of magnetic materials, a magnetic film having a large coercive force as a recording medium (magnetic desk), a soft magnetic material having a large saturation magnetization as a recording head, and As the reproducing head, a soft magnetic material having a good response speed is required. Among these problems, it is expected that the magnetic disk is a Co—Pt—Cr film having a large coercive force of 2000 Oe or more, and the reproducing head can be cleared by developing a spin valve or a tunnel junction type MR head. However, no suitable material has yet been found for a soft magnetic film for a recording head. Similar problems with soft magnetic materials are also emerging in fields such as micro-transformers and inductors that operate in the high frequency band.

In recent years, an Fe-based soft magnetic microcrystalline film having a large saturation magnetization has been developed as a material for a magnetic head for high-density recording, and it seems that the problem relating to the soft magnetic film for a recording head has already been solved. Certainly, since the existing Fe-based soft magnetic microcrystalline film has a large Bs, it exhibits excellent overwrite characteristics even for a recording medium having a large coercive force. However, when the recording density is further increased, it is conceivable that the current magnetic material having a magnetic resonance frequency of about 100 MHz has a problem with the frequency characteristic of the magnetic permeability. Even today, the outer peripheral speed of a large hard disk drive system is at 100 MHz. Therefore,
A characteristic required for a magnetic recording head material of a next-generation ultra-high-density compact hard disk system is that it exhibits excellent frequency dependence of magnetic permeability up to around 100 MHz in addition to the conventional large saturation magnetization. Therefore, in addition to a large saturation magnetization, a high electric resistance and a large anisotropic magnetic field are required for the soft magnetic material. The Fe-based high-Bs soft magnetic microcrystalline film described above has a large μ ′ because it has almost no uniaxial magnetic anisotropy, but does not have good μ-f characteristics in a high-frequency band, and is a next-generation It can easily be inferred that the high-density magnetic recording system cannot be endured. From the above, there is a need for a soft magnetic thin film material having a large electric resistivity, anisotropic magnetic field, and saturation magnetization and exhibiting good frequency dependence of magnetic permeability up to high frequencies even in a single-layer film.

The present invention has been made in view of the above points, and has as its object to provide a soft magnetic thin film having excellent electric resistance, anisotropic magnetic field, and saturation magnetization exhibiting excellent soft magnetic characteristics up to a high frequency range. .

[0008]

Means for Solving the Problems The present inventors have made intensive efforts in view of the above circumstances, and as a result, have found that Co-containing a small amount of oxygen.
The inventors have found that a film having both high saturation magnetization, electric resistance, and anisotropic magnetic field, and exhibiting good high-frequency soft magnetic properties even with a single-layer film can be obtained with the Fe-Al-based film, which has led to the present invention. .

The first invention is based on the general formula Co
_100-X-Y-Z shown in Fe _X M Y _{O Z} (atomic%), are the respective atomic ratios 10 <X <50 2 <Y <10 6 <Z <25 15 <X + Y + Z <65, M Is A whose heat of formation of oxide is -1000 kJ or more.
1, Zr, Ti, Hf, Mg, Be, or one or more of the rare earth elements, and has an anisotropic magnetic field of 200O.
e, an electric resistivity value of 50 μΩcm or more, and a saturation magnetic flux density of 16 kG or more.

The second invention is based on the general formula Co
_100-X-Y-Z shown in Fe X _Al Y _{O Z} (atomic%), are the respective atomic ratios 10 <X <50 2 <Y <10 6 <Z <25 15 <X + Y + Z <65, different An isotropic magnetic field of 20 Oe or more and an electric resistivity of 5
A magnetic thin film having a magnetic flux density of 0 μΩcm or more and a saturation magnetic flux density of 16 kG or more.

A third invention is a magnetic thin film having a multilayer structure in which the magnetic thin films and the ceramic thin films according to the first and second inventions are alternately laminated.

A fourth invention is the magnetic thin film according to the first and second inventions, wherein less than 40% of the oxygen concentration in the film is replaced by nitrogen atoms, the anisotropic magnetic field is 30 Oe or more, and the electrical resistivity is Value is 50 μΩcm or more and saturation magnetic flux density is 1
A magnetic thin film having 5 kG or more.

A fifth invention is a high-density magnetic recording head comprising the magnetic thin film according to any one of the first to fourth inventions.

According to a sixth aspect of the present invention, there is provided an inductor comprising the magnetic thin film according to any one of the first to fourth aspects of the present invention, which operates at 1 MHz or more.

According to a seventh aspect of the present invention, there is provided a transformer, comprising the magnetic thin film according to any one of the first to fourth aspects of the invention, operating at 1 MHz or more.

[0016]

[Action]

In order for the magnetic film of the present invention to have a high saturation magnetic flux density (Bs) of 16 kG or more, it is not sufficient to use Co alone as a magnetic atom, and it is necessary to use an alloy system substituted with 10% or more of Fe. . However, in a film having an Fe concentration of 50% or more, Bs becomes large, but Hk becomes less than 20 Oe, and the film eventually becomes a magnetically isotropic film. Further, in order to realize soft magnetism, the film needs to be composed of crystal grains having a grain size of 20 nm or less. For that purpose, an oxide element has a heat of formation of about 1000 kJ or more.
Al, Zr, Hf, Mg, Be or a rare earth element) must be contained at 2% or more. However, M element concentration is 10%
Above this, Bs becomes 16 kG or less. When the oxygen concentration is 6% or less, the oxidation of the M element is insufficient, the particle size does not become small, and soft magnetism is not realized. On the other hand, 25%
In this case, the Co—Fe element is also oxidized, the magnetization becomes small, and the film becomes a perpendicular magnetization film.

As the film of the present invention, a film showing Bs of 16 kG or more and having a large electric resistivity of 200 μΩcm or more was not obtained. However, since the film thickness required when manufacturing a magnetic device is 1-2 μm or less,
Eddy current losses are not very large. However, in order to compensate for this, it is necessary to increase the resonance frequency of the magnetic permeability to around 1 GHz. For this purpose, it is desirable that Hk is 20 Oe together with high Bs.

[0019]

Embodiments of the present invention will be described below by comparing the results with those of a conventional Fe-based microcrystalline film and a nano-granular structure soft magnetic film.

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

Example 1 A (Co. ₇ Fe. ₃ ) ₉₂ Al ₈ (at.%) Target was subjected to a Co—Fe—Al— sputtering by a reactive sputtering method in an (Ar + O ₂ ) mixed gas atmosphere using an RF magnetron sputtering apparatus. An O thin film was produced. The film forming conditions were set as follows.

Sputter gas pressure 6 × 10 ⁻³ Torr Input power 200 W Substrate temperature 20 ° C. Substrate Coming # 7059 (thickness 0.5 mm) Film thickness 2.0-3.0 μm Oxygen flow ratio 0.0-1.0% Applied magnetic field 130 Oe (pair of permanent magnets)

The direct current magnetic characteristics of the obtained sample were measured by a sample vibration magnetometer. The results are shown in FIG. The two data in the figure are parallel to the direction of application of the magnetic field during film formation (//),
It shows the result of measurement by exciting vertically (⊥). The sample has uniaxial magnetic anisotropy parallel to the direction of the magnetic field applied during film formation, and the magnitude of the anisotropic magnetic field is about 45 Oe.
And it was big enough. In addition, a vertical hysteresis curve (B-
As is clear from the result of (H hysteresis loop), it is inferred that the straightness of the loop is good and the anisotropic dispersion of the film is small. The greatest feature of the obtained film was the magnitude of the saturation magnetic flux density (Bs), and the value was as large as 17.8 kG. The coercive force (Hc) of this film is as small as about 1.0 Oe in both the vertical and parallel directions, indicating that it is a soft magnetic film. The electrical resistivity (p) of this film measured by the DC four-terminal method is about 100 μΩcm, which is almost the same value as that of the amorphous film. FIG. 2 shows the frequency dependence of the magnetic permeability of the film of the present invention measured by the parallel line method. The broken line is a theoretical formula based on Landau and Lifshitz's equation of motion (Jinbo, Tsunashima, Uchiyama: Journal of the Japan Society of Applied Magnetics,
14, 289 (1990)). Despite having a large Bs of 17 kG or more, the permeability is 400
It shows good frequency dependence up to MHz and is almost in agreement with the result of the theoretical formula.

[0023]

EXAMPLE -2] under the same conditions as in Example 1, to prepare a Co-Fe-Y-O film using a composite target in which paste the _Y 2 _{O 3} chips Co-Fe target. DC magnetic characteristics and AC magnetic characteristics of the obtained sample were measured.
FIG. 3 shows an example of the frequency dependence of the magnetic permeability of the obtained film. Also shown in the figure are the measurement results of the DC magnetic characteristics. As apparent from the figure, the magnetic permeability of the obtained film is Co-Fe-
Similar to the result of the Al—O film, the value shows a value of about 300 and shows good frequency dependency. Approximately the same results were observed for films of other composition systems of the present invention.

[0024]

Embodiment 3 In a conventional high electric resistance soft magnetic film, it is known that M atoms and oxygen atoms are preferentially bonded to form a grain boundary, which greatly affects the magnetic characteristics of the film. ing. To clarify the effect of M _Y O _Z of concentration on the magnetic properties of the present invention films, under the same conditions as in Example -1, Co
With the ratio of Fe and Fe constant, only the N concentration is 0 to 15%
Co-Fe-A using an alloy target changed to
An l-O film was produced. FIG. 4 shows the results of Bs obtained from the measurement results of the DC magnetic characteristics. As a result of the analysis, the concentration ratio between Al and oxygen in the obtained film was approximately 1: 3, and was indicated as (Al. ₂₅ O. ₇₅ ) in the drawing. (A in the membrane
l. ₂₅ O. ₇₅ ) Even if the concentration (y + z) increases,
The decrease of Bs in the -Fe-Al-O film is small as compared with that calculated as simple dilution by (Al-O) atoms. In the film of the present invention, N having a large heat of formation is selectively bonded to oxygen to form an Al-O compound, so that Co-Fe is released, and a large magnetic moment is maintained even when the Co-Fe concentration changes. Inferred. Thus, the film of the present invention has Al and Co because Al and oxygen coexist in the film.
Alloying with -Fe to prevent large Bs from spreading over a wide range (Al
_- O) is realized by concentration.

Next, the electric resistivity (p) of these films is expressed by A
FIG. 5 shows the results arranged for 1 concentration. The increase rate of p does not show much difference between the composition systems of the films. The p of the film of the present invention increases almost linearly with an increase in the (Al _- O) concentration, and exceeds 100 µΩcm at 25% (Al _- O) or more. For such a large p, there are two factors: the formation of a grain boundary between Al and O of the film of the present invention and the reduction of the crystal grains of the film.
It is presumed that one of them contributes.

The Hc of the Co—Fe—Al—O film is shown in FIG.
Shown in As is clear from the figure, Hc is remarkably reduced as the (Al-O) concentration increases, and the Hc becomes wider (Al-O).
It shows a value of 20e or less in the concentration range. As described above, it is presumed that the film of the present invention realizes good soft magnetism due to the coexistence of Al and oxygen in the film. The origin is discussed in the structure section.

The anisotropic magnetic field (Hk) of the film of the present invention is (Al-
FIG. 7 shows the results organized by O) concentration. The Hk of the film of the present invention in the range exhibiting soft magnetism increases with an increase in the (Al-O) concentration. For example, in a film containing 20% or more of (Al-O), Hk of about 30 Oe or more is realized.

As is clear from the results shown in FIGS.
In the film of the present invention, the values of Bs, p, and Hk are determined by (Al—O) in the film.
By selecting the concentration, it can be determined almost uniquely.

In order to clarify the influence of the Al and O concentrations on the characteristics of the film of the present invention, the structure of the film was examined by an X-ray diffraction method. In order to clarify the effect of each atom of Al and O, the expression of the film composition is expressed as (Co. ₇ Fe.
₃₎ and _{100-y Al y (Co. 7} Fe. 3)
Indicated by _100-yz AlyOz. Of the comparative example in FIG. _{8 (Co. 7 Fe 3.)} 100-y Al y film (a) and a membrane of the present invention _{(Co. 7 Fe 3.) 100} - y -Z Aly
Shows the diffraction pattern of O _Z film (b). (Co. ₇ Fe. ₃ )
_{1 00-y} Al y film has an essentially BCC structure, Al
Even if the concentration is changed, the diffraction pattern does not show much change. On the other hand, in the film of the present invention, a large change is observed in the crystal orientation and the line width depending on the (Al-O) concentration. That is,
As the Al concentration increases, the (110) plane becomes the preferred orientation,
In addition, the line width increases.

The results of these diffraction patterns are calculated based on the crystal grain size (D).
FIGS. 9 and 10 show the arrangement by the surface spacing (d). Here, D is a value calculated using the Sherer's formula (Karite (Translated by Matsumura Gentaro): Introduction to X-ray Diffraction, Agne Corporation, 1980). The D of the Co—Fe—Al film gradually increases with the increase of the Al concentration, whereas the D of the film of the present invention containing oxygen is generally smaller than that of the Co—Fe—Al film, and It shows a tendency to decrease with an increase in concentration, and rapidly decreases in a film of 10% Al or more,
That value is less than 50 ° (FIG. 9). Having such a small particle size is based on the Herzer microcrystal model (G.
Herzer: IEEE Trans. onMag. 2
6 1397 (1990)), which is considered to be the main cause of soft magnetism. Co-Fe
Since the crystal grains composed of have a BCC structure, the easy magnetization direction of the film exists in the plane, and it can be inferred that this contributes to soft magnetization. Such a film structure is A
It is thought to be due to the selective oxidation of l. That is, also in the present invention, Al is preferentially linked to oxygen in the sputtering gas during film formation to form a grain boundary in the film, and the grain boundary is increased as the Al concentration increases, so that the crystal grains are refined. it is conceivable that. This idea is supported by FIG. The interplanar spacing d of the film of the present invention hardly changes even when the Al concentration increases, whereas that of Co—Fe—Al
Increases with increasing concentration. This increase is due to the fact that Al is Co-F
It is considered to be between e lattices and expand the lattice distance. On the other hand, in the film of the present invention, even if the Al concentration is increased, it is considered that the grain boundary is formed by combining with oxygen and Al atoms do not enter between Co—Fe lattices, so that the lattice spacing does not change.

[0031]

[Table 1]

Table 1 shows the measurement results of typical examples of the typical thin film according to the present invention, which are produced by a method substantially similar to that of the above-described embodiments, and are summarized by Bs, p, Hk, and Hc. . As a comparative example, the result of a conventional soft magnetic film is shown. Some films such as Fe-Ta-N films are 1
It shows a large Bs of 7 kG or more, but Hk is extremely small. On the other hand, the Co-based high electric resistance film shows large Hk and p, but Bs is 15 kG or less. On the other hand, each of the films of the present invention has Hk and p of appropriate sizes, and Bs>
16 kG has been realized. As described above, a Co—Fe—MO alloy based film containing a small amount of an element having a large heat of formation of an oxide is soft magnetic, has a suitable Hk and p, and has a large Bs. Was confirmed.

As described above, the natural resonance frequency (fr) that causes the magnetic permeability to deteriorate in the high frequency band is Hk and Bs
Is proportional to the product of FIG. 11 shows Hk, p and B of the film of the present invention.
mu was calculated from s _- f characteristics (a), Q-f characteristic obtained from mu-f characteristic (b): shows the results of (Q performance index). As a comparative example, the result of an Fe—Ta—N film well known as an existing high Bs soft magnetic film is also shown. FIG.
As shown in (a), the Fe-Ta-N film has a large H 'due to a small Hk, but also has a large μ', which causes resonance at around 100 MHz. In the films, large Bs and Hk are synergistic, and μ ′ maintains a constant value up to about 1 GHz.The results of organizing these films by the figure of merit are shown in FIG. In addition, as compared with the known Fe-Ta-N film, the film of the present invention has a large Q of about one digit and a high resonance frequency.

[0034]

Example 4 In order to obtain a film exhibiting excellent frequency dependence of magnetic permeability up to a further higher frequency band, the film of the present invention was mixed with SiO ₂ , Al ₂ O ₃ and Al under the same conditions as in Example 1.
A laminated film with N was produced. The thickness of each magnetic film was set to 0.5 μm or less, and the thickness ratio of the magnetic layer to the ceramic layer was set to 4: 1 or less. Magnitude of 18
In a multilayer film composed of a magnetic film of kG or more, even if the multilayer film is formed, the magnitude of magnetization of the entire film does not become 15 kG or less, and Hk hardly changes. The effect of the multi-layer film appears in the reduction of the eddy current loss, and the resonance frequency of the magnetic permeability is 2G.
Hz. Another effect of the multilayer film is the appearance of magnetostatic coupling between the magnetic layers. The soft magnetic properties are further improved by this coupling force, and the anisotropic dispersion is extremely reduced. As described above, in the multilayer film using the film of the present invention as a magnetic film, since the Bs of the magnetic film is large, it is possible to obtain a film showing excellent frequency dependence of magnetic permeability without reducing Bs so much. Can be done. Table 1 shows a multilayered Co—Fe—A—O / Al ₂ O ₃ film and C
The result of the o-Fe-YO / SiO ₂ film is shown.

The magnetic thin film Co100-xy of the present invention is used.
-ZFexMyOz exhibits excellent soft magnetic characteristics in a high frequency band as described above, but this is due to V, Nb, Ta, Cr,
Mo, Mn, Ni, Cu, Si, Ge, B, Ca, etc.
The addition of a species or two or more elements for the purpose of improving high-frequency characteristics is within the scope of the technical idea of the present invention,
Of course, it may be added.

[0036]

As described above, according to the present invention, it is possible to provide a thin film material which is a soft magnetic thin film having a large anisotropic magnetic field, a saturation magnetization and a large electric resistivity, and which has excellent high frequency characteristics. The thin film of the present invention has a saturation magnetization that is not inferior to that of the conventional Fe-based microcrystalline film and an appropriate anisotropic magnetic field, so that the resonance frequency is high and the electrical resistivity is also high. Since the size is almost the same as that of the amorphous soft magnetic material, the eddy current loss is small, and the frequency characteristics of good magnetic permeability can be maintained up to a high frequency. Further, since the film of the present invention has a large saturation magnetization and excellent frequency dependence of magnetic permeability, when used as a core material of a recording magnetic head, it has an ultra-high recording density having a large coercive force. Since it is considered that a recording medium can be sufficiently overwritten, its industrial significance is great.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the B- of a Co ₅₅ Fe ₂₃ Al ₆ O ₁₆ film produced using a (Co. ₇ Fe. ₃ ) ₉₂ Al ₈ target.
H hysteresis loop.

FIG. 2 is a characteristic diagram showing frequency dependence of magnetic permeability of a Co ₅₅ Fe ₂₃ Al ₆ O ₁₆ film.

FIG. 3 is a characteristic diagram showing the frequency dependence of the magnetic permeability of a Co ₅₂ Fe ₂₂ Al ₇ O ₁₉ film.

[4] _{(Co. 7 Fe. 3)} 100- (y + z) (A
l. ₂₅ O. ₇₅ ) Bs of _{(y + z)} film and (Al-O)
FIG. 4 is a characteristic diagram showing a relationship with a density.

FIG. 5: (Co. ₇ Fe. ₃ ) _{100- (y + z)} (A
l. ₂₅ O. ₇₅ ) A characteristic diagram showing a relationship between p of the _{(y + z)} film and (Al-O) concentration.

FIG. 6: (Co. ₇ Fe. ₃ ) _{100- (y + z)} (A
l. ₂₅ O. ₇₅ ) Hc of _{(y + z)} film and (Al-O)
FIG. 4 is a characteristic diagram showing a relationship with a density.

FIG. 7: (Co. ₇ Fe. ₃ ) _{100- (y + z)} (A
l. ₂₅ O. ₇₅ ) Hk of _{(y + z)} film and (Al-O)
FIG. 4 is a characteristic diagram showing a relationship with a density.

FIG. 8 shows a sample (Co. ₇ F) manufactured by changing the Al concentration.
e. _{3) 100-y-z AlyO} z film and _(Co. 7 F
e. _{3) 100-y} Al y film and X-ray diffraction pattern of.

FIG. 9: (Co. ₇ Fe. ₃ ) _100-yz Al _y O
_z film and _{(Co. 7 Fe 3.) 100} - y Al y characteristic diagram showing the relationship between the grain size and the Al concentration determined from the X-ray diffraction pattern of the film.

FIG. 10: (Co. ₇ Fe. ₃ ) _100-yz Al _y
O _z layer and _{(Co. 7 Fe. 3) 100} -y Al y film X
FIG. 4 is a characteristic diagram showing a relationship between a plane interval and an Al concentration obtained from a line diffraction pattern.

FIG. 11 is a film (Co ₅₀ Fe ₃₂ Al ₄ O ₁₄ ) of the present invention.
FIG. 6 is a characteristic diagram showing the frequency dependence of the magnetic permeability and the figure of merit obtained from the calculations of the Fe and Ta-N films.

Claims (7)

[Claims] 1. A general formula _{Co 100-X-Y-Z} Fe X M Y
_OZ (atomic%), and the respective atomic ratios are 10 <X <502 2 <Y <10 6 <Z <25 15 <X + Y + Z <65, and M is an oxide having a heat of formation of -1000 kJ or more. A
l, Zr, Ti, Hf, Mg, Be, and one or more of the rare earth elements, having an anisotropic magnetic field of 20 Oe or more, an electrical resistivity of 50 μΩcm or more, and a saturation magnetic flux density of 16 kG. A magnetic thin film having the above. 2. A compound of the general formula Co _{100-XYZ Z} Fe _X Al
_Y O _Z (atomic%), each atomic ratio is 10 <X <502 2 <Y <10 6 <Z <25 15 <X + Y + Z <65, the anisotropic magnetic field is 20 Oe or more, and the electric resistivity is Value 5
A magnetic thin film having a magnetic flux density of 0 μΩcm or more and a saturation magnetic flux density of 16 kG or more. 3. A magnetic thin film having a multilayer structure in which the magnetic thin films and the ceramic thin films according to claim 1 are alternately laminated. 4. The magnetic thin film according to claim 1, wherein less than 40% of the oxygen concentration in the film is replaced by nitrogen atoms, the anisotropic magnetic field is 20 Oe or more, and the electric resistivity is 50 μm.
A magnetic thin film having a Ωcm or more and a saturation magnetic flux density of 16 kG or more. 5. A high-density magnetic recording head comprising the magnetic thin film according to claim 1. 6. An inductor, comprising the magnetic thin film according to claim 1, which operates at 1 MHz or higher. 7. A transformer comprising the magnetic thin film according to claim 1 and operating at 1 MHz or higher.