JP2774705B2 - High saturation magnetic flux density soft magnetic film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic film, and more particularly to a soft magnetic film having a high saturation magnetic flux density suitable as a material for a magnetic head for high density recording.

[0002]

2. Description of the Related Art With the demand for higher density of magnetic recording, the coercive force of magnetic recording media has been energetically increased.
Recording media having a coercive force close to 500 to 2000 Oe (Oersted) have been obtained. In order to perform sufficient recording on such a recording medium, a magnetic head core material having a high saturation magnetic flux density is required. In fact, considering the future progress of increasing the coercive force of the recording medium, the core material of the magnetic head for high density recording is 15000G.
(Gauss) or higher saturation magnetic flux density is required.

Conventionally, as a core material of a magnetic head,
Permalloy, Sendust, Co-based amorphous alloys and the like are known. In these materials, the maximum value of the saturation magnetic flux density in a range where soft magnetism can be maintained is approximately 10,000 G for Permalloy and approximately 13,000 G for Sendust.
13000 to 1500 for G and Co based amorphous alloys
0G. Among the above, Co-based amorphous alloys are promising, but if the saturation magnetic flux density is increased, the thermal stability will be reduced, and the soft magnetism will be degraded by high temperature treatment (such as glass welding) in the magnetic head manufacturing process. There is a problem in the reliability as a head.

As described above, it is difficult for the currently known core material for a magnetic head to sufficiently bring out the capability of a high coercive force medium, and to realize a high density magnetic recording in the future, a soft material having a higher saturation magnetic flux density will be required. The development of magnetic materials is desired.

[0005]

As a material having a saturation magnetic flux density of 15000 G or more, Fe or an alloy containing Fe as a main component (Fe-Al, Fe-Si, etc.) is conventionally known. However, when a magnetic film of Fe or an alloy containing Fe as a main component is formed by a normal film forming technique such as a sputtering method for use as a core material of a high-density magnetic recording head, the saturation magnetic flux density Can be increased to 15000G or more, but the coercive force increases,
It was difficult to obtain sufficient soft magnetism. In order to solve this problem, multilayering of the magnetic film and the like have been performed, but problems such as insufficient characteristics and a complicated manufacturing process remain.

Accordingly, the present inventors have disclosed a high saturation magnetic flux density soft magnetic film having a saturation magnetic flux density of 15000 G or more in a single-layer film in Japanese Patent Application No. 2-26851 filed on Oct. 5, 1990. We are applying for a patent.

One of the magnetic films according to this patent application is Fe
_x M _Y O _z (where M represents at least one element of Zr and Hf, and _x , _Y , and _Z each represent atomic%), and the above-mentioned _x , _Y , _Z Is 70 ≦ _x ≦ 96, 1 ≦ _Y ≦ 1
The composition was such that 2, 3 ≦ _Z ≦ 25 and _x + _Y + _Z = 100, and _Y and _Z satisfied the relationship of 1.5 _Y ≦ _Z ≦ 4.0 _Y.

[0008] The magnetic film according to the patent application is 15000
It is an excellent soft magnetic thin film having a saturation magnetic flux density of G or more.
Generally, soft magnetic materials used for magnetic heads and the like are:
The smaller the coercive force, the more preferable. In use in a high frequency region, the smaller the coercive force, the smaller the electric resistance is. Therefore, an object of the present invention is to provide a soft magnetic film having a high saturation magnetic flux density of 15000 G or more and a lower coercive force than the magnetic film according to the patent application, and to provide a softer magnetic film than the magnetic film according to the patent application. An object of the present invention is to provide a soft magnetic film having a large resistance and a small eddy current in a high frequency region.

Further, in the manufacturing process of the MIG (metal-in-gap) magnetic head, there is a glass welding process for simultaneously bonding a magnetic core and forming a gap with a welding glass.
At this time, the magnetic head is usually 50 to weld the glass.
It will be heated to a high temperature of 0 ° C to 600 ° C. Therefore, the soft magnetic thin film used in the MIG magnetic head needs to have not only high saturation magnetic flux density but also excellent thermal stability such that the magnetic properties are not deteriorated by high-temperature heating in the glass welding step. However, the magnetic film according to the patent application has a problem in that the soft magnetic characteristics are deteriorated by heating at a temperature higher than 500 ° C., and thus the magnetic film is not suitable for a magnetic head including a glass welding process in a manufacturing process. Therefore, another object of the present invention is to provide a soft magnetic film having a high saturation magnetic flux density of 15000 G or more, a low coercive force, and excellent thermal stability.

[0010]

SUMMARY OF THE INVENTION The first aspect of the present invention in order to solve the above _{problems, Fe x M Y O z Q} w ( where M is, among Zr and Hf, represents one or more elements , Q is C
And N, one or more of X, Y, Z, and W each represent atomic%. ) Represented by the composition formula, the X, Y, Z, W is, Q is C
When X is N, 70 ≦ X <96, and when Q is N, 70 ≦ X
<89, 1 ≦ Y ≦ 12, and Q includes C
3 ≦ Z ≦ 25, and when Q is N, 10 <Z ≦ 25
In other words, the composition is such that W ≦ 26 and X + Y + Z + W = 100. In order to solve the above-mentioned problem, the invention according to claim 2 is characterized in that F _x M _Y O _z R _w (where M is Z
R and Hf represent one or more elements, R represents one or more of Si, B, Al and Y, and X, Y, Z and W each represent atomic%. ), Wherein X, Y, Z, and W are 7
0 ≦ X <96, 1 ≦ Y ≦ 12, 3 ≦ Z ≦ 25, W ≦ 26, X
+ Y + Z + W = 100.

[0011]

The present invention will be described below in more detail. In the high saturation magnetic flux density soft magnetic film having the above composition, Fe (iron)
Is a main component and is an element responsible for magnetism.
In order to obtain a saturation magnetic flux density of 5000 G or more, X ≧ 7
It must be 0 atomic%. The element M (M is Z
r (zirconium), Hf (at least one element of hafnium)) and O (oxygen) are elements necessary for obtaining soft magnetism, and M and O are simultaneously added to Fe in a specific amount to form a film. Soft magnetism is significantly improved. In order to obtain good soft magnetic properties, the content of M and O in the film should be 1 atomic%.
≦ Y ≦ 12 at% and Z ≦ 25 at% .

Q represents one or more of C (carbon) and N (nitrogen). By containing one or more of C and N, the coercive force can be made lower than before. By the way, in the thin film magnetic head, a resin having low heat resistance such as a photoresist is used as an insulating layer between the upper and lower magnetic layers, and the magnetic film to be used cannot be subjected to a heat treatment of 400 ° C. or more. In this regard, if C and N are contained as shown in the embodiment, a sufficiently low coercive force can be obtained without performing a heat treatment at 400 ° C. or more, which is advantageous. Here, X ≧ 70 atomic%, Y ≧ 1 atomic%, Z ≧ 3
From atomic%, W ≦ 26 atomic%. W is naturally W> 0, Y
≧ 1 atomic%, Z ≧ 3 atomic%, X + Y + Z + W = 100, X
<96 atomic%. When Q is N, X ≧ 70
Atomic%, Y ≧ 1 atomic%, Z> 10 atomic%, W ≦ 26 atomic
%. W is naturally W> 0, Y ≧ 1 atomic%, Z> 10
%, X <89 atomic% from X + Y + Z + W = 100.
You. In such a composition, high saturation magnetic flux density
The soft magnetic properties of the film can be further improved.

In particular, in a composition where Q is N and 1 at% <Y <5 at%, 10 at% <Z <13 at% , and W <24 at % , the coercive force after high-temperature heat treatment is lower than that of the conventional one. can do. As described above, in the manufacturing process of the MIG (metal-in-gap) magnetic head, a fixing process using a welded glass is included, so that the magnetic head is heated to a high temperature (500 ° C. to 600 ° C. depending on the type of the welded glass) during the manufacturing. . In this regard, as shown in the examples, the magnetic film of the present composition has an excellent property that a sufficiently low coercive force can be maintained even after heating at a high temperature (500 ° C. to 600 ° C.).

R is Si (silicon), B (boron) and Al
One or more of (aluminum) and Y (yttrium) are shown. By including one or more of these, electrical resistance can be increased, eddy current loss in a high frequency region can be reduced, and magnetic permeability at a high frequency can be increased. The range of X, Y, Z and W is 70 ≦ X <
96, 1 ≦ Y ≦ 12, 3 ≦ Z ≦ 25, W ≦ 26, X + Y + Z +
W = 100.

Incidentally, the high saturation magnetic flux density soft magnetic film of the present invention is used for the purpose of adjusting the magnetostriction constant and improving the corrosion resistance.
Other elements can be added to the quaternary composition as long as the saturation magnetic flux density is not significantly reduced or the soft magnetism is not deteriorated.

The high saturation magnetic flux density soft magnetic film of the present invention is produced by a general thin film production method such as a sputtering method or a vacuum evaporation method, and there is no particular limitation on the film production method.

When the high saturation magnetic flux density soft magnetic film of the present invention is produced by the sputtering method, an existing apparatus such as DC sputtering, RF sputtering, magnetron sputtering, facing target type sputtering, or ion beam sputtering apparatus is used. can do. As a method of adding O or N to the film, Ar + O ₂ or Ar + O ₂ in which oxygen gas or nitrogen gas is mixed in an inert gas such as Ar.
Reactive sputtering, in which sputtering is performed in a ₂ + N ₂ mixed atmosphere gas, is effective. Further, Fe, Fe-M, or F
e-MQ (M is at least one element of Zr and Hf, Q is at least one element of C, B, Si, Al and Y) on an alloy target, Fe, M or Q
It can also be manufactured in an inert gas such as Ar using a composite target in which an oxide or nitride of the above is disposed.

[0018]

[Example 1] Fe-Hf-based, Fe-Hf-C-based, Fe-H
f-B system, Fe-Hf-Si system, Fe-Hf-Al system,
Each of the Fe—Hf—Y alloy targets is appropriately used, and
+ O ₂ (0.1 to 1.0%) gas atmosphere or Ar +
Film formation was performed in an O ₂ (0.1 to 1.0%) + N ₂ (0.5 to 10%) gas atmosphere. The main sputtering conditions are shown below. Preliminary evacuation 1 × 10 ⁻⁵ Pa or less High frequency power 400 W Ar gas pressure 1.0 Pa Substrate Crystallized glass substrate (indirect water cooling) Distance between electrodes 70 mm The sputtering time was adjusted so that the film thickness at the time of production was 2 μm. The composition of each magnetic film is determined by inductively coupled plasma (ICP) emission spectrometry and X-ray microanalyzer (EPMA).
Determined by The saturation magnetic flux density and the coercive force were measured by VSM.

A number of samples were prepared under the above manufacturing conditions, and the magnetic properties and electric resistance of each sample were measured.

FIG. 1 shows an Fe-Hf-OC system, Fe-Hf
The relationship between the C or N content in the -ON-based magnetic film and the coercive force (Hc) after the heat treatment at 300 [deg.] C. or less, as-formed, is shown in FIG. 2, and the Fe-Hf-O-N is shown in FIG. 4 shows the relationship between the heat treatment temperature (annealing temperature) and the coercive force in a magnetic film of the present invention.

From the results shown in FIG. 1, the magnetic film of the present invention has C
Alternatively, it has been found that the coercive force decreases as the N content increases. It can also be seen that heat treatment at a temperature of 400 ° C. or higher is not required to obtain a low coercive force.

From the results shown in FIG. 2, it can be seen that Fe--Hf--O--N
It has been found that the coercive force of the system film hardly changes as it is after the heat treatment at a temperature higher than 500 ° C. as compared with the conventional film. On the other hand, the sample of the comparative example is 500
It can be seen that the coercive force is increased by the heat treatment at a temperature higher than ℃.

FIGS. 3 and 4 show that the samples manufactured by the above-described method show the Fe—Hf—O—B system and the Fe—Hf—O—S system.
For each of the i-type, Fe-Hf-O-Al-type, and Fe-Hf-OY-type samples, the change in specific resistance (ρ) with respect to the B content, the Si content, the Al content, and the Y content is shown. . From the results shown in FIGS. 3 and 4, it was confirmed that the specific resistance can be improved by adding any of B, Si, Al and Y.

Next, the Fe-Hf-O produced by the above method is used.
Table 1 shows the measurement results of the saturation magnetic flux density (Bs) and the coercive force after the heat treatment at 300 ° C. or lower for the —C-based and Fe—Hf—ON-based magnetic films. Fe
-Hf-ON-based film with saturation magnetic flux density and 500 ° C.
Table 2 shows the measurement results of the coercive force after the heat treatment at 600 ° C.
Shown in Fe-Hf-OB, Fe-Hf-O-Si,
Table 3 shows the measurement results of the saturation magnetic flux density, the specific resistance, and the coercive force after the heat treatment at 400 ° C. to 500 ° C. for the Fe—Hf—O—Al and Fe—Hf—O—Y based films.

From the results shown in Table 1, it was found that the magnetic film according to the present invention containing C or N exhibited a saturation magnetic flux density exceeding 15,000 G and had a lower coercive force than the conventional example. From the results shown in Table 2, it was confirmed that the magnetic film according to the present invention containing N exhibited a saturation magnetic flux density exceeding 15,000 G and exhibited a low coercive force even in a heat treatment at 500 ° C. to 600 ° C. In order to obtain such a low coercive force, the N content in the film must be 2%.
It can be seen that the O content must be less than 4 atomic%, the O content must be between 10 atomic% and 13 atomic%, and the Hf content must be between 1 atomic% and 5 atomic%. From the results shown in Table 3, it is clear that among the magnetic films according to the present invention, the magnetic film containing B, Si, Al or Y has a saturation magnetic flux density exceeding 16000 G, a low coercive force, and a high specific resistance. Was. Therefore, the magnetic film having the composition shown in Table 3 has a small eddy current loss in a high frequency region and can increase the magnetic permeability at a high frequency.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

As described above, according to the first aspect of the present invention, since a predetermined amount of Zr or Hf, O, C or N is added to Fe, a saturation magnetic flux exceeding 15000 G is obtained. It is possible to provide a magnetic film having a characteristic that the density is high and the coercive force is lower than that of a conventional film. In particular, when a specific amount of N is added, it is possible to provide a soft magnetic film having excellent thermal stability with almost no deterioration of soft magnetic characteristics even when heated at a temperature higher than 500 ° C. Therefore, the magnetic film of the present invention is a material suitable for a magnetic head having high performance for high-density recording.

According to the second aspect of the present invention,
By adding a predetermined amount of Zr or Hf, O, Si, B, Al or Y to Fe, a saturation magnetic flux density exceeding 16000 G is exhibited, and the specific resistance is high, and the eddy current loss in a high frequency region is increased. It is possible to provide a magnetic film having a high magnetic permeability in a high-frequency range with a small amount. Therefore, by applying the magnetic film of the present invention to a magnetic head, it is possible to provide a magnetic head having high magnetic permeability in a high frequency range and high recording characteristics.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the coercive force and the contents of C and N in a film of a sample of the present invention.

FIG. 2 is a graph showing a relationship between a coercive force of an N-added film and an annealing temperature in a sample of the present invention.

FIG. 3 shows the specific resistance and B,
It is a graph which shows the relationship with Si, Al, and Y content X.

FIG. 4 is a graph showing the relationship between the specific resistance and the B, Si, Al, Y content X in the sample of the present invention after annealing at 500 ° C.

Claims (2)

(57) [Claims] 1. A _{Fe x M Y O z Q w} ( where M is, among Zr and Hf, represents one or more elements, Q is of C and N, represents one or more, X, Y, Z and W each represent atomic%)), and the above-mentioned X, Y, Z, W
However, when Q contains C, 70 ≦ X <96, and when Q is N
At this time, 70 ≦ X <89, 1 ≦ Y ≦ 12, and Q is C
When Z is 3 ≦ Z ≦ 25, and when Q is N, 10 <Z ≦
25. A high saturation magnetic flux density soft magnetic film characterized by having a composition of W ≦ 26 and X + Y + Z + W = 100. Wherein _{Fe x M Y O z R w} ( where M is, among Zr and Hf, represents one or more elements, R represents among Si, B, Al and Y, represents one or more, _x , _Y , _Z , and _W each represent an atomic%.) wherein _x , _Y , _Z , and _W are 70 ≦ _x <96, 1 ≦ _Y ≦ 12,
A high saturation magnetic flux density soft magnetic film having a composition of 3 ≦ _Z ≦ 25, _W ≦ 26, and _x + _Y + _Z + _W = 100.