JPH0439905A - Magnetically soft alloy film - Google Patents

Abstract

PURPOSE:To obtain this film whose coercive force is small, whose permeability is high, whose characteristic is thermally stable, whose saturation magnetic flux density is high and whose corrosionresistant property is good by a method wherein a metal film composed of fine crystals indicated by a specific formula is used. CONSTITUTION:A metal film indicated by the following is used: its compositional formula is indicated by FeaXdMeCf (where X is one or more kinds of elements out of Y, Ru, Ir, Rh and N or their mixture, M is at least one or more kinds of metal elements out of Ti, Zr, Hf, V, Nb, Ta, Mo and W or their mixture and its compositional ratio of a, d, e and f satisfies a relationship of 50<=a<=95, 0.5<=d<=10, 2<=e<=25, 0.5<=f<=25 in terms of atomic % and a+d+e+f=100); its texture is composed of fine crystal particles at an average crystal particle size of 0.08mum or lower; and its one part contains a crystal phase of a carbide of the elements of M.

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, increasing the coercive force of recording media such as magnetic tapes is being promoted in order to increase the recording density. A high level of quality is required.

As a conventional soft magnetic material (film) with high saturation magnetic flux density, F
The e-5i-A I alloy (Sendust) is a typical example, but in recent years, amorphous alloy films mainly containing Co, a ferromagnetic metal element, have been developed.

In addition, as a recent attempt, alloy films made of fine crystals mainly composed of Fe (Fe-C, Fe-8i, etc.)
Effect of magnetocrystalline anisotropy of Fe (adverse effect on soft magnetism)
There is an example in which a film with high saturation magnetic flux density and excellent soft magnetic properties was obtained by reducing this by making crystals finer.

[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, magnetic heads must not only have excellent magnetic properties and wear resistance against magnetic tape, but also durability in corrosive atmospheres such as high humidity atmospheres, that is, environmental resistance, and durability. High vibration properties are required.

Therefore, it is necessary to perform gap formation, assembly into a case, etc. by glass welding, and the material of the magnetic head needs to be able to withstand the high temperatures of the glass welding process in the head manufacturing process.

However, among the conventional soft magnetic alloy films, those made of sendust have a saturation magnetic flux density of about 10,000G.
(Gauss), which is insufficient to meet future demands for higher density layers. In addition, some Co-based amorphous alloy films have a high saturation magnetic flux density of 13,000 G or more, but when trying to increase the saturation magnetic flux density of conventional amorphous alloys, the amorphous forming element T
I.

It is necessary to reduce the amounts of Zr, Hf, Nb, Ta, Mo, W, etc. added. However, when the amount of these additives is reduced, the stability of the amorphous structure decreases, and there is a problem that it cannot withstand the temperature (approximately 5000 C or more) required for glass welding.

Furthermore, the alloy films (Ft-C, Fe-5i, etc.) made of fine crystals mainly composed of Fe described above undergo crystal growth at high temperatures, resulting in deterioration of soft magnetic properties (in the case of Fe-C). , 400°C (maximum), it is still difficult to say that it is suitable for glass welding.

Against this background, the inventors of the present invention have proposed patent application No. 1-278
No. 220, etc., patent applications have been filed for soft magnetic alloy films that solve the above-mentioned problems.

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

In addition, the other one has a compositional formula of FeiTbMcCd, the compositional ratio a is 5o to 96 atomic %, and b is 0.1 to 10
, C is 2-30. d is 0.5-25, a+b+c+d-
This satisfied the relationship 100.

The soft magnetic alloy film provided in this patent application has a high saturation magnetic flux density of 15,000 G or more in the case of a partially assembled acid, and has high thermal stability compared to various conventional materials, and under normal usage environments. Although it has sufficient corrosion resistance and environmental resistance,
Since Fe is the main component, there is a risk of discoloration or development if used in adverse environments.

Therefore, as a result of repeated research aimed at improving the corrosion resistance, the inventors of the present application improved the corrosion resistance by adding 0.5 to 20 at. After finding out that it could be obtained, he filed a patent application for a soft magnetic alloy film with excellent corrosion resistance in Japanese Patent Application No. 2-63808.

Further, the inventors of the present application conducted research to improve the corrosion resistance of this type of soft magnetic alloy film, and as a result, they arrived at the present invention.

The present invention solves the above-mentioned problems and provides a soft magnetic alloy film that has low coercive force, high magnetic permeability, thermally stable characteristics, high saturation magnetic flux density, and good corrosion resistance. The purpose is to

[Means for solving the problem] In order to solve the problem, the invention described in claim 1 has the following features:
The compositional formula is FeaXdMeCl, where X is Y, Ru
, I is an element consisting of at least one or more of r, Rh, and N, or a mixture thereof; M is Ti and Zr.

It is a metal element or a mixture thereof consisting of at least one of Hf, V, Nb, Ta, Mo, and W, and the composition ratios s, d, e, and f are 50≦1≦95.0 in atomic %. 5
≦d≦1O12≦e≦25.0.5≦f≦25, a+d
It satisfies the relationship 10e+1-100, and its structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and a part thereof contains a crystal phase of carbide of element M.

The invention described in claim 2 has a solution to solve the above problem,
The compositional formula is shown as Fe*T b

An element consisting of at least one of Rh and N, or a mixture thereof, M is Ti, Zr, Hf, V, Nb
,T! , M o.

A metal element consisting of at least one type of W or a mixture thereof, and the composition ratios i, b, d, e, f are 50 atomic %.
≦a≦95.0.1≦b≦10.0.5≦d≦1O12
≦e≦25.0.5≦f≦25.1+b10d10e+1-
The structure satisfies the relationship 100, and the structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and a part thereof includes a crystal phase of carbide of element M.

In order to solve the above problem, the invention described in claim 3 has the following features:
It is represented by the compositional formula Fe5CrcX dM eCf, where X is Y
, Ru, Ir, Rh, and a mixture thereof; M is TI.

Z r, HI, V, N b, T! , MO, and W, or a mixture thereof, and the composition ratio s, c, d, *, f is 50≦Hatake≦9 in atomic %.
5.0.1≦e≦20.0.5≦d≦10.2≦e≦2
5.0.5≦f≦25, a+ c+ d+ e+ f=
The structure satisfies the relationship 100, and the structure basically consists of fine crystal grains with an average crystal grain size of 0.08 μm or less, and a part thereof contains a crystal phase of carbide of element M.

Claim 4I In order to solve the above problem, the described invention is represented by the composition formula Fe*T bcrcX dM eCf, where T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and , Ru, Ir.

An element or mixture of at least one of Rh and N, M is Ti, Zr, Hf, V, Nb, Ta, M
o.

A metal element consisting of at least one type of W or a mixture thereof, with a composition ratio of 1 + b + C + d l e
+ f is atomic% 50≦1≦95.0.1≦b≦10
．． 0.1≦e≦20.0.5≦d≦10.2≦e≦25
．． 0.5≦1≦25, i+b+c+d+e+f=10
The structure satisfies the relationship 0, and the 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 claim 1, 2.3 or 4 has an average grain size of 0.
．． It has a structure in which fine crystal grains of 0.8 μm or less and an amorphous phase are mixed, and a part thereof includes 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, a method may be adopted in which the alloy film is produced using a thin film forming apparatus such as a sputtering apparatus or a vapor deposition apparatus. Examples of the sputtering apparatus include RF bipolar sputtering, DC sputtering, Magnetron sputter, 3
Existing sputtering methods such as polar sputtering, ion beam sputtering, and facing target sputtering can be used.

However, as a method of adding C to the film, there is a method of placing graphite pellets on a target plate to form a composite target and sputtering this, or a method of sputtering a composite target that does not contain C (Fe-X- M series or F e-T
-X-M system, etc.) and sputtering in a gas atmosphere containing a mixture of a hydrocarbon gas such as methane (C H4) in an inert gas such as Ar, etc. can be used. Since the sputtering method allows easy control of the C concentration in the film, a film with an excellent desired C concentration can be obtained. Further, as a method for adding nitrogen into the film, a method of sputtering in (Ar+N) gas can be used.

The nitrogen concentration in the film can be adjusted by changing the N2 concentration (Nz/ArN2 value) in the (ArN2) gas.

The film as produced in this way contains a considerable proportion of amorphous phase and is unstable.
Microcrystals are precipitated by heat treatment at a temperature of about 00 to 700°C. This heat treatment is then carried out without a magnetic field.
Excellent soft magnetic properties can be obtained by performing the process in a static magnetic field or a rotating magnetic field. Further, this heat treatment can be performed concurrently with the glass welding step in the manufacturing process of the magnetic head.

Note that the step of precipitating the microcrystals does not need to be performed completely, and it is sufficient that a considerable number of microcrystals (preferably 5% or more) are precipitated, so there is no problem even if some amorphous components remain. Therefore, the remaining amorphous components do not become an obstacle to improving the properties.

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

Fe is the main component and is an element responsible for magnetism, and in order to obtain a saturation magnetic flux density at least higher than ferrite (Bs=5000 G), 2250% is required. Also,
In order to obtain good soft magnetic properties, n≦95% must be satisfied.

Element T (ie, Co, Ni) is an element added for the purpose of adjusting magnetostriction. In the case of a Fe-MC film, the magnetostriction becomes positive when the heat treatment temperature is low, and the magnetostriction becomes negative when the heat treatment temperature is high. When a high heat treatment temperature (glass welding temperature) is required, the magnetostriction can be made almost zero by adding an appropriate amount of Ni or Co, which has the effect of making the magnetostriction positive.

Note that, if the heat treatment temperature is appropriate, addition of element T is not particularly necessary, but the addition of element T must be such that ≦b≦10% so that the positive magnetostriction does not increase beyond +10-'.

Element M (Ti, Zr, Hf, V, Nb, Tx, Mo)
is necessary to improve soft magnetic properties, and also combines with carbon to form fine carbide crystals. In order to maintain good soft magnetic properties, it is necessary to set it to 0.022%.
If it is too large, the saturation magnetic flux density will decrease, so C≦2
It needs to be 5%.

C is necessary to improve soft magnetic properties and 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 to set f≧0.5%, but if it is too large, the saturation magnetic flux density will decrease, so f≦25%. There is a need to.

The carbide microcrystals of element M act as pinning sites for the domain wall, improving the high-frequency characteristics of magnetic permeability, and by uniformly dispersing them in the film, Fe microcrystals grow through heat treatment, resulting in soft magnetic properties. It has the function of preventing damage to the In other words, as the crystal grains of Fe grow and become larger, the negative effect of magnetocrystalline anisotropy increases and the soft magnetic properties deteriorate. Prevents deterioration of magnetic properties.

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

Cr is an element added to improve corrosion resistance, but the effect of improving corrosion resistance does not appear unless C20.1% is added. Further, when C>20%, the saturation magnetic flux density becomes too low (below ferrite), which is not preferable.

The reason for limiting the Cr content explained above is in Japanese Patent Application No. 2-63808.
This is equivalent to the case of No.

Element X (Y, Ru, It, Rh, N) is an element added to improve corrosion resistance, but at 0.5%
If the above amount is not added, the effect of improving corrosion resistance will not be sufficient.

Furthermore, if the amount added exceeds 10%, the saturation magnetic flux density becomes too low and good soft magnetic properties cannot be obtained, which is not preferable.

Since the metal structure basically consists of microcrystals with a size of 0-OS μm or less, it has superior thermal stability compared to amorphous materials, can reduce the amount of added elements, and can increase the saturation magnetic flux density. can.

[Function] 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 amount per iron atom is smaller than that in the amorphous state. The magnetic moment and Curie temperature are high, resulting in a high saturation magnetic flux density. Also, elements M and C
In addition, the metal structure is made up of fine crystal grains, which reduces the adverse effect of magnetocrystalline anisotropy on soft magnetism, so that good soft magnetic properties can be obtained.

Furthermore, 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 even when heated in the glass welding process. Furthermore,
Since a specific amount of Cr is added and, if necessary, a specific amount of element X is added, corrosion resistance is improved and environmental resistance is excellent.

Unlike conventional amorphous alloys, a sufficiently high initial magnetic permeability can be obtained even by non-magnetic field annealing, and the heat treatment process can be simplified.

[Example] (1) Film Formation An alloy film having a composition shown in Table 1 below was formed using an RF two-pole sputtering device.

The target used was Ta on Fe target.

Sputtering is performed in an Ar gas atmosphere or an Ar+N gas atmosphere using a composite target composed of appropriately arranged pellets of Cr, Y, Ru, Ir, Ni, and graphite to form a film with a thickness of 5 to 6 μm. A thin film was formed. Note that the nitrogen concentration in the alloy film is controlled by (A r+N
2) The N2 gas concentration in the gas was controlled.

(2) Heat treatment After film formation, annealing was performed at 550°C for 20 minutes. This annealing was performed in a static magnetic field.

(3) Measurement The saturation magnetic flux density (Bs) and initial magnetic permeability (μ,
5MH resistance and coercive force (Hc) were measured. In addition,
The initial permeability and coercive force were measured in the direction of the hard magnetization axis of the thin film.

The above results are shown in Table 1 on the next page.

Sample 1 of the comparative example in Table 1 was previously applied for a patent by the present inventors, and only the addition of element X was omitted. It was found that adding a certain amount of ferromagnetic material caused almost no problem with the deterioration of soft magnetic properties such as initial permeability and coercive force.It was also revealed that good initial permeability could be obtained by non-magnetic field annealing. Ta.

A soft magnetic alloy film prepared in the same manner as above was placed in pure water for 2 hours.
The results of visually determining the discoloration after 40 hours of immersion are shown in Table 2 below.

(Hereinafter, blank space) Table 2 By adding specific amounts of elements X and Cr, a soft magnetic alloy film with excellent corrosion resistance can be obtained without deteriorating the soft magnetic properties. It became clear that

[Effects of the Invention] As detailed above, the present invention is a soft magnetic alloy film mainly composed of fine crystal grains containing Fe as the main component, and limits the addition of components that reduce the saturation magnetic flux density. Therefore, a high saturation magnetic flux density can be obtained.

Further, 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, and the process can be simplified compared to when heat-treated by applying a magnetic field.

Element M (T i, Z r, HI, V , N b, T a
, Mo, W) and C that improve soft magnetism, and the metal structure is composed of fine crystal grains to reduce the negative effect of magnetocrystalline anisotropy on soft magnetism. Good soft magnetic properties can be obtained.

Furthermore, since it is composed of fine crystal grains and the added element M forms a carbide with C, the crystal grains do not become coarse even when heated in the glass welding process, and the above characteristics are maintained. It is suitable as a material for magnetic heads that have the high performance required for high-density recording.

Furthermore, by adding elements T (Co, Ni) in addition to the above composition to adjust the magnetostriction, it is possible to prevent deterioration of the soft magnetic properties due to various strains occurring in the manufacturing process of the magnetic head.

Then, the element X (Y, Ru, Ir,
Since specific amounts of Rh, N) or elements X and Cr are added, it has excellent corrosion resistance as an Fe-based alloy, and does not discolor or develop even when used in adverse environments. be.

Claims (1)

[Claims] (1) The compositional formula is FeaXdMeCl, where X is Y,
An element consisting of at least one of Ru, lr, Rh, N, or a mixture thereof; M is Ti, Zr, Hf, V, N
A metal element consisting of at least one of b, Ta, Mo, and W, or a mixture thereof, with a composition ratio a, d, e, f
satisfies the following relationships in atomic %: 50≦a≦95 0.5≦d≦10 2≦e≦25 0.5≦f≦25 a+d+e+f=100, and the structure basically has an average grain size of 0. Consisting of fine crystal grains of 0.08 μm or less,
A soft magnetic alloy film characterized in that a part thereof contains a crystal phase of a carbide of element M. (2) The compositional formula is FeaTbXdMeCf, where T is a metal element consisting of at least one of Co and Ni, or a mixture thereof, and X is an element or mixture thereof consisting of at least one of Y, Ru, Ir, Rh, and N. the mixture, M is Ti
, Zr, Hf, V, Nb, Ta, Mo, and W, or a mixture thereof, and the composition ratio a, b, d, e, f is 50≦a≦95 in atomic %. 0.1≦b≦10 0.5≦d≦10 2≦e≦25 0.5≦f≦25 a+b+d+e+f=100 In addition to satisfying the following relationships, the structure basically has an average crystal grain size of 0.08 μm or less. Consisting of fine crystal grains,
A soft magnetic alloy film characterized in that a part thereof contains a crystal phase of a carbide of element M. (3) It is represented by the composition formula FeaCrcXdMeCf, where X is an element consisting of at least one of Y, Ru, Ir, Rh, and N, or a mixture thereof, and M is Ti, Zr, Hf,
A metal element consisting of at least one of V, Nb, Ta, Mo, and W, or a mixture thereof, with a composition ratio a, c, d
, e, f satisfy the following relationships in atomic %: 50≦a≦95 0.1≦c≦20 0.5≦d≦10 2≦e≦25 0.5≦f≦25 a+c+d+e+f=100 The structure basically consists of fine crystal grains with an average grain size of 0.08 μm or less,
A soft magnetic alloy film characterized in that a part thereof contains a crystal phase of a carbide of element M. (4) Represented by the composition formula FeaTbCrcXdMeCf,
T is a metal element consisting of at least one of Co and Ni, or a mixture thereof; X is an element or a mixture thereof, consisting of at least one of Y, Ru, Ir, Rh, and N; M is Ti, Zr, Hf, Among V, Nb, Ta, Mo, and W,
It is a metal element consisting of at least one kind or a mixture thereof, and the composition ratio a, b, c, d, e, f is 50≦a≦ in atomic%.
95 0.1≦b≦10 0.1≦c≦20 0.5≦d≦10 2≦e≦25 0.5≦f≦25 a+b+c+d+e+f=100 In addition to satisfying the following relationships, the organization basically Consists of fine crystal grains with an average crystal grain size of 0.08 μm or less,
A soft magnetic alloy film characterized in that a part thereof contains a crystal phase of a carbide of element M. (5) The structure according to claim 1, 2, 3 or 4 is a structure in which fine crystal grains with an average crystal grain size of 0.08 μm or less and an amorphous phase are mixed, and a part of the structure contains element M. A soft magnetic alloy film characterized by containing a carbide crystal phase.