JPH0412508A - Soft magnetic alloy film - Google Patents

Abstract

PURPOSE:To obtain a soft magnetic alloy film having high permeability, thermally stable characteristics and satisfactory corrosion resistance by composing it of a film represented by a composition formula of FeaXcMeCf. CONSTITUTION:A composition formula is represented by FeaXcMeCf, where X is at least one of elements of Al, Si or mixture thereof, M is at least one of T, Zr, Hf, V, Nb, Ta, Mo, W or mixture thereof, composition ratios (a), (c), (e), (f) are by atomic % 50<=a<=95, 0.2<=c<=25, 2<=e<=25, 0.5<=f<=25, a+c+e+f=100 to be satisfied. The composition is fundamentally formed of fine crystalline grains of 0.08mum of average crystal grain size, and the crystal phase of carbide of M is partly included. Thus, satisfactory soft magnetic properties are obtained, and a soft magnetic alloy film which has durability against heat hysteresis in a process of magnetic head of a complicated structure, permeability in high frequency, excellent corrosion resistance, prevention of deterioration of soft magnetic properties is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a soft magnetic alloy film suitable for magnetic heads and the like.

``Prior Art'' In the field of magnetic recording, efforts are being made to increase the coercive force of recording media such as magnetic tapes in order to increase the recording density. A high (Bs) is required.

Conventional soft magnetic materials (films) include N1-Fe (permalloy) and Co-based amorphous films.

In addition, recently, in alloy films (Fe-N, Fe-C, etc.) consisting of fine crystals containing Fe as the main component, the negative effects of Fe's magnetocrystalline anisotropy on soft magnetism have been reduced by making the crystals finer. There is an example in which a film with high saturation magnetic flux density and excellent soft magnetic properties was obtained.

``Problem to be solved by the invention'' Incidentally, devices incorporating magnetic heads tend to be smaller and lighter, and are often exposed to vibrations caused by movement or used in adverse environments. It has become.

Therefore, the magnetic head has a magnetic property of f! ! In addition to being excellent in abrasion resistance against magnetic tape, it is also required to have high durability in humid and corrosive atmospheres, that is, high environmental resistance and vibration resistance. Therefore, it is necessary to form the gear and incorporate it into the case by glass welding, and the material for the magnetic head is also required to have thermal stability that can withstand the high temperatures of the glass welding process in the manufacturing process of the head.

However, in the conventional soft magnetic alloy film, N
A film made of an i-Fe film has the disadvantage that its soft magnetic properties deteriorate and its electrical resistance is low at high temperatures during the glass welding process.

Furthermore, in Co-based amorphous films, high saturation magnetic flux densities of 13,000 G or more have been obtained, but when trying to increase the saturation magnetic flux density of conventional amorphous alloys, Ti, an amorphous forming element, is used.

It is necessary to reduce the amount of Zr, Hf, Nb, Ta, Mo, W, etc. added, but if the amount added is reduced, the stability of the amorphous structure will decrease, and the temperature required for glass welding (approximately 500°C or higher) will decrease. has an unbearable problem.

If the saturation magnetic flux density is suppressed to about 9000 G or less, welding with low melting point glass is possible, but welding at temperatures above 600° C. is difficult, and medium to high melting point glasses with excellent environmental resistance cannot be used.

Furthermore, the above-mentioned alloy films (Fe-N, Fe-C, etc.) consisting of fine crystals mainly composed of Fe undergo crystal growth at high temperatures, resulting in deterioration of soft magnetism (in the case of Fe-C, the
℃), so it is difficult to say that it is suitable for glass welding.

Against this background, the inventors of the present application have proposed the patent application No. 12782
No. 20, etc., a patent application has been filed for a soft magnetic alloy film that solves the above problem. Furthermore, in a patent application filed on March 14, 1990, a patent application has been filed for a soft magnetic alloy film that solves the above problem.

One of the soft magnetic alloy films for which a patent application has been filed in Japanese Patent Application No. 1-278220 has a composition formula of FeaMcCd.
The composition ratio a is 50 to 96 atomic %, and C is 2 to 3.
0 and d satisfied the relationship of 0.5 to 25 and a+c+d=100.

The other one is represented by the composition formula FeaTbMcCd, where the composition ratio a is 5θ~96 in atomic %, and b is 0.1-1o.
, C is 2-30, d is 0.5-25, a+b+c+d=
This satisfied the relationship 100.

Furthermore, one of the soft magnetic alloy films for which a patent application was filed on March 14, 1990 has a composition formula of FeaCrcMdCe.
The composition ratio a is 50 to 95 in atomic %, and C is 0.5.
~20, d is 2-25, e is 0.5-25, a+c+d
This satisfied the relationship: 10e=100.

Furthermore, the other one has a compositional formula of FeaTbCrc
It is represented by MdCe, the composition ratio a is 5θ~95 in atomic %, and b
is 0.1-10, C is 0.5-20, d is 2-25, e
was 0.5 to 25, and satisfied the following relationship: a+b+C+d+e=100.

The soft magnetic alloy films provided in these patent applications have a high saturation magnetic flux density of 15,000 G or more in the case of partial acid.
It has high thermal stability compared to various conventional materials, and has sufficient corrosion resistance and environmental resistance under normal usage environments. Then, the soft magnetism will deteriorate. For ordinary magnetic heads, glass welding is possible at temperatures below 700°C, but for heads with complex structures, for example, heads with an integrated erase head and recording/playback head, It is necessary to form the gap by glass welding, and then to combine (combine) both heads with glass welding at a temperature at which the gap bonding glass does not melt, and it is necessary to use a gap bonding glass with a high melting point.

For this reason, it is desirable to form the initial gap at a high temperature of 700° C. or higher. Therefore, a soft magnetic thin film with even higher heat resistance is required.

In addition, the soft magnetic alloy film filed in the above-mentioned Japanese Patent Application No. 1-278220 has a low electrical resistance, about half that of a conventional amorphous film. , there was a problem that it was lowered. Furthermore, since Fe is the main component, there is a risk of discoloration or rusting when used in adverse environments.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a soft magnetic alloy film that has high magnetic permeability, is thermally stable, and has good corrosion resistance. It is something.

"Means for Solving the Problems" In order to solve the problems, the present invention described in claim 1 is represented by a compositional formula or FeaXcMeCf, where X is Al,
Si is an element consisting of at least one kind or a mixture thereof, and M is Ti, ZrHf, V, Nb, T
It is a metal element consisting of at least one of a, Mo, and W, or a mixture thereof, and the composition ratios a, c, e, and f are atomic %.
So, 50≦a≦95.0.2≦c≦25.2≦e≦25
．． It satisfies the following relationships: 0.5≦f≦25, a+C+e+f=100, and its structure basically consists of fine crystal grains with an average grain size of 0.08 μm or less, and some of them contain carbides of element M. It contains a crystalline phase of

In order to solve the above problem, the invention described in claim 2 has the following features:
The compositional formula is Pea

It is a metal element or a mixture thereof consisting of at least one of Zr, Hf, V 2 , Nb, Ta, Mo, and W, and the composition ratios a, c, d, e, and f are in atomic % and are 50≦a≦95.
02≦c≦25.0.1≦d≦2012≦e≦25.0
It satisfies the following relationships: 5≦f≦25, B+c+d+e+, f=l 00, and its structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and some of them contain carbides of element M. It contains a crystalline phase of

In order to solve the above problem, the invention described in claim 3 has the following features:
The compositional formula is FeaT bX cM eCf, T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and X is an element consisting of at least one of Al and Si, or a mixture thereof, M is T
i, Zr, Hf, V, Nb.

It is a metal element or a mixture thereof consisting of at least one of Ta, Mo, and W, and the composition ratios a, b, c, e, and f are atomic %, and 50≦a≦95.0.1≦b≦1O102≦
c≦25, 2≦e≦25, 0.5≦f≦25, a+
1) Satisfy the relationship -i-c+e+f=100, and the structure basically has an average grain size of 0.08μ
It is made up of fine crystal grains of the following size and includes a crystal phase of carbide of element M in a part thereof.

In order to solve the above problem, the invention described in claim 4 has the following features:
The compositional formula is peaT bX c CrdM eCf, T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and X is an element consisting of at least one of Al and Si, or a mixture thereof. , M is Ti, Zr, HfV, Nb, Ta, Mo, W
A metal element consisting of at least one of the following, or a mixture thereof, and has a composition ratio of a and b.

c, d, e, f are atomic %, 50≦a≦95, o, i≦
b≦l010.2≦c≦25, Ol≦d≦20.2≦e
≦25.0.5≦f≦25, a+b+ c+d+e+f
= 100, and its structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and a portion thereof includes a crystal phase of carbide of element M.

In order to solve the above problem, the invention described in claim 5 has the following features:
The structure according to claims 1 to 4 has an average crystal grain size of 0.08.
It is a structure in which fine crystal grains of μm or less and amorphous are mixed, and a part of the fine crystal grains contains a crystal phase of carbide of element M.

The present invention will be explained in more detail below.

As a method for producing the alloy film, the alloy film is produced using a thin film forming apparatus such as sputtering or vapor deposition. As the sputtering apparatus, existing ones such as RF two-pole sputtering, DC sputtering, magnetron sputtering, three-pole sputtering, ion beam sputtering, and facing target sputtering can be used.

In addition, as a method of adding C into the film, a graphite pellet is placed on a target plate to form a composite target, and this is sputtered, or a target that does not contain C (Fe-X-M system, Fe -X-Cr-M system, Fe-T-X-M system or Fe-T-X-C
methane (C) in an inert gas such as Ar.
A reactive sputtering method in which sputtering is performed in a gas atmosphere containing a mixture of hydrocarbon gases such as H, ), etc. can be used. In particular, the reactive sputtering method allows easy control of the Ca content in the film, so that the desired carbon content can be achieved. It is possible to obtain a film with excellent concentration.

The film as produced in this way contains a considerable proportion of amorphous phase, has a low saturation magnetic flux density, and has insufficient soft magnetic properties. Precipitate microcrystals. Good soft magnetic properties can be obtained even if this heat treatment is performed in the absence of a magnetic field, but excellent magnetic properties can be obtained by performing this heat treatment in a static or rotating magnetic field. Further, this heat treatment can be performed concurrently with the glass welding step in the manufacturing process of the magnetic head.

It should be noted that the step of precipitating the microcrystals does not need to be performed completely; it is sufficient that a considerable number of microcrystals (preferably 50% or more) are precipitated, so there is no problem even if some amorphous components remain. , the remaining amorphous components do not impede the improvement of properties.

The reasons for limiting the components as described above will be described below.

Fe is the main component and is an element responsible for magnetism.

In order to obtain a saturation magnetic flux density of at least ferrite (Bs 5000G) or higher, a≧50 at% is required. In addition, in order to obtain good soft magnetic properties, a≦95
Must be at%.

Element T (ie, Co, Ni) is an element added for the purpose of adjusting magnetostriction. In a film without the addition of element T, the magnetostriction takes a positive value when the heat treatment temperature is low or when the amount of Si added is small, and conversely, when the heat treatment temperature is high or the amount of Si added is large. The magnetostriction takes a negative value. The heat treatment temperature at which the magnetostriction becomes zero also depends on the concentrations of elements M and C. However, if it is necessary to increase the amount of Si added and raise the heat treatment temperature (glass welding temperature),
Magnetostriction becomes negative, so element T has the effect of making magnetostriction positive.
(ie, co, Ni), the magnetostriction can be adjusted to zero. Note that, if the heat treatment temperature and the amount of Si added are appropriate, addition of element T is not particularly necessary. However, the amount of element T added must be such that b≦l0at% so that the positive magnetostriction does not increase to more than +1O−5.

Element M (i.e. Ti, Zr, Hf, V, Nb,
Ta, W) is necessary to improve soft magnetic properties, and also combines with C to form fine crystals of carbide.

These fine particles of carbide serve to prevent the growth of crystals containing Fe as a main component, resulting in high heat resistance.

In order to maintain good soft magnetic properties, it is necessary that e≧2at%. However, if it is too large, the saturation magnetic flux density will decrease and the soft magnetic properties will deteriorate, so e≦2
It is necessary to set it to 5 at%.

C is necessary to improve soft magnetic properties and improve heat resistance, and C combines with element M to form fine crystals of carbide.

In order to maintain good soft magnetic properties and thermal stability, it is necessary that f≧0.5 at%. however,
If it is too large, the saturation magnetic flux density and soft magnetic properties will be lowered, so it is necessary that f≦25 at%.

The reasons for limiting the components of Fe, element T, element M, and C described above are almost the same as in the case of Japanese Patent Application No. 1-278220.

Element X (i.e., Al, Si) functions to lower the crystal magnetic anisotropy energy of fine crystals mainly composed of Fe and maintain soft magnetic properties even if the crystal size grows to a certain extent. It is possible to improve heat resistance.

Furthermore, it has the function of increasing electrical resistance and improving the decrease in high frequency magnetic permeability caused by eddy current loss.

In order to exhibit the above effects, at least C20,2
It is necessary to set it to at%. However, if the content of element X is too high, the saturation magnetic flux density will decrease, so C≦
It needs to be 25 at%.

Cr is an element added to improve corrosion resistance and environmental resistance. Although sufficient corrosion resistance and environmental resistance can be obtained for practical use without the addition of Cr, the corrosion resistance and environmental resistance can be improved by adding Cr for use in more severe environments. In order to improve corrosion resistance and environmental resistance, the Cr content must be d≧0.1 at%. However, if the Cr content is too high, the saturation magnetic flux density becomes too low (below ferrite), so d≦
Is it necessary to set it to 20at%?

By uniformly dispersing the carbide microcrystals of element M in the film, they have the function of preventing Fe microcrystals from growing and coarsening due to heat treatment and impairing soft magnetism. In other words, as Fe crystal grains grow and become larger, the negative effect of magnetocrystalline anisotropy becomes greater and the soft magnetic properties deteriorate.
The carbide microcrystals of element M act as a barrier to grain growth of Fe, thereby preventing deterioration of soft magnetic properties.

In the present invention, the addition of element It has the characteristic that soft magnetic properties can be maintained even when

Furthermore, since the metal structure basically consists of microcrystals with a size of 0.08 μm or less, it has superior thermal stability compared to amorphous materials, allowing for fewer additive elements and higher saturation magnetic flux density. I can do it.

"Effect" The structure of the soft magnetic alloy film is mainly composed of Fe-rich crystals, and the addition of components that reduce the saturation magnetic flux density is limited, so the The magnetic moment and Curie temperature are high, and a high saturation magnetic flux density can be obtained. In addition, the elements M and C are included, and the metal structure is made up of fine crystal grains, which reduces the negative effect of magnetocrystalline anisotropy on soft magnetism, resulting in good soft magnetic properties. . moreover,
Since the carbide of element M precipitates and suppresses the growth of crystal grains mainly composed of Fe, the crystal grains do not become coarse due to heating in the glass welding process.

Furthermore, since a specific amount of Cr is added, corrosion resistance is improved and environmental resistance is excellent.

Furthermore, the addition of element X (Al, Si) increases electrical resistance, reduces eddy current loss at high frequencies, and increases high frequency magnetic permeability.

"Example" (1) Film Formation An alloy film having a composition shown in Table 1 below was formed using an RF bipolar sputtering device.

The f-ni target used is Sl on the Fe target.

A thin film having a thickness of 5 to 6 μm was formed by sputtering in an Ar gas atmosphere using a composite target configured by appropriately arranging various pellets of Al, Co, Ta, graphite, and the like.

(2) Heat treatment After film formation, annealing was performed at 650° C. for 20 minutes in a non-magnetic field.

(3) Measurement The alloy film produced as described above and the alloy film not containing element X formed by sputtering (Japanese Patent Application No. 1-27822
The saturation magnetic flux density (B s
), initial permeability (μ, atlMHz), coercive force (Hc),
The magnetostriction constant (λ) and specific resistance (ρ, μΩ·cm) were measured. The above results are shown in Table 1.

Comparative Example a of Sample 1 in Table 1 is the one for which the present invention company has previously applied for a patent. All alloy films (b-k) according to the present invention have higher specific resistance (electrical resistance) than a, and have the same magnetic properties (saturated magnetic flux density, initial permeability, coercive force, magnetostriction constant) as a. Or even higher values have been obtained.

Table 2 shows the thermal stability (heat resistance) of the soft magnetic properties of the alloy film prepared by the same method as described above in comparison with that of the alloy film filed in Japanese Patent Application No. 1-278220.

From Table 2 below, it can be seen that the alloy film of the present invention exhibits higher thermal stability than the alloy films listed in the comparative examples.

Further, the specific resistance after heat treatment at 750° C. showed a value about three times higher than that of the comparative example.

[Effect of the Invention J As explained above, the present invention is a soft magnetic alloy film mainly composed of fine crystal grains containing Fe as the main component, and the addition of components that lower the saturation magnetic flux density is limited. , high saturation magnetic flux density can be obtained.

This makes it possible to provide a magnetic head with high recording characteristics.

Furthermore, unlike conventional amorphous alloy films, it is possible to obtain a film that exhibits high magnetic permeability even when heat-treated in the absence of a magnetic field. It can be simplified more than the case.

In addition, elements M (Ti, Zr, Hf, V, Nb, T
Components such as a, Mo, W) and C that improve soft magnetism are added, and the metal structure consists of fine crystal grains, which reduces the negative effect of magnetocrystalline anisotropy on soft magnetism, so it is good. Soft magnetic properties can be obtained.

Furthermore, as well as being composed of fine crystal grains, the added element M forms a carbide with C, and the carbide is uniformly dispersed in the film, so that microcrystals mainly composed of Fe grow through heat treatment. It works to prevent this from happening. In other words, it serves to prevent deterioration of soft magnetism due to the increase in the negative influence of magnetocrystalline anisotropy as the crystal grows.

In addition to the above composition, element X (A l, Si)
By adding , the magnetocrystalline anisotropy energy on the sides of the Fe-based crystal decreases, and even if the crystal grows to some extent, it maintains its soft magnetic properties and can withstand heat treatment at high temperatures. . This makes it possible to use a highly reliable medium to high melting point glass as the welding glass, and also to withstand the thermal history of the manufacturing process of a magnetic head with a complex structure that requires multi-step glass welding. .

Furthermore, by adding Si or At, the electrical resistance increases, eddy current loss at high frequencies is reduced, and magnetic permeability at high frequencies can be increased.

Furthermore, by adding the element T (Co, Ni), it is possible to adjust the magnetostriction and prevent deterioration of the soft magnetic properties due to various strains generated in the manufacturing process of the magnetic head.

Furthermore, by adding a specific amount of Cr to the above components, F
As an e-based alloy, it has excellent corrosion resistance and does not discolor or rust even under adverse environments.

Claims (1)

[Claims] (1) The compositional formula is FeaXcMeCf, where X is Al
, Si, or a mixture thereof, and M is Ti, Zr, Hf, V, Nb, Ta.
, Mo, and W, and the composition ratios a, c, e, and f are 50≦a≦95 0.2≦c≦25 2≦e≦25 0. It satisfies the following relationship: 5≦f≦25 a+c+e+f=100, and its structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, with a crystal phase of carbide of element M in a part of it. A soft magnetic alloy film comprising: (2) The compositional formula is FeaXcCrdMeCf, and
is an element consisting of at least one of Al and Si, or a mixture thereof; M is Ti, Zr, Hf, V, Nb
, Ta, Mo, and W, or a mixture thereof, and has a composition ratio of a, c, d, e, f.
satisfies the following relationships in atomic %: 50≦a≦95 0.2≦c≦25 0.1≦d≦20 2≦e≦25 0.5≦f≦25 a+c+d+e+f=100, and its structure is basically A soft magnetic alloy film comprising fine crystal grains having an average crystal grain size of 0.08 μm or less, and containing a crystal phase of a carbide of element M in a part thereof. (3) The compositional formula is FeaTbXcMeCf, T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and X is an element consisting of at least one of Al and Si, or a mixture thereof, M is T
A metal element consisting of at least one of i, Zr, Hr, V, Nb, Ta, Mo, and W, or a mixture thereof,
Composition ratios a, b, c, e, f are in atomic %, 50≦a≦95 0.1≦b≦10 0.2≦c≦25 2≦e≦25 0.5≦f≦25 a+b+c+e+f=100 A soft magnetic material that satisfies the following relationship and whose structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and a part of which contains a crystal phase of carbide of element M. Alloy membrane. (4) The compositional formula is FeaTbXcCrdMeCf, T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and X is a metal element consisting of at least one of Co and Ni, and
An element consisting of at least one kind or a mixture thereof,
M is a metal element consisting of at least one of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, or a mixture thereof, and the composition ratios a, b, c, d, e, and f are 50≦at%. a≦95 0.1≦b≦10 0.2≦c≦25 0.1≦d≦20 2≦e≦25 0.5≦f≦25 a+b+c+d+e+f=100 In addition to satisfying the following relationships, the organization is basic. A soft magnetic alloy film comprising fine crystal grains having an average crystal grain size of 0.08 μm or less, and containing a crystal phase of a carbide of element M in a part thereof. (5) The structure according to claims 1 to 4 has an average crystal grain size of 0.
．． A soft magnetic alloy film characterized by having a mixed structure of fine crystal grains of 0.08 μm or less and amorphous, and containing a crystal phase of carbide of element M in a part of the fine crystal grains.