JPH03265105A - Soft magnetic laminate film - Google Patents

Abstract

PURPOSE:To make it a high saturation magnetic flux density film by laminating a soft magnetic alloy metals of texture being FexMzCw and Fe layers alternately, and making the soft magnetic alloy metal consist of minute crystal grains whose average grain diameter is specified, and making one part of it contain the carbide crystal phase of the element M. CONSTITUTION:Soft magnetic alloy metals 4 shown by the composition formula of FexMzCw and Fe layers 3 are stacked alternately. The magnetic alloy metal 4 entirely consists of minute grains whose average diameter is 0.08mum or less, and one part of it contains the crystal phase of the carbide of the element M. But, M is the element metal consisting of at least one kind among Ti, Zr, Hf, V, Nb, Ta, Mo, and W or their mixture, and the composition ratio among x, z, and w meets the relations of 50<=x<=96, 2<=z<=30, 0.5<=w<=25 by atom% and x+z+w=100. This way, a film, which exhibits high saturation magnetic flux density and high permeability even if it is heat-treated in nonmagnetic field, can be gotten.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soft magnetic laminated film with a high saturation magnetic flux density suitable for magnetic heads and the like.

[Prior Art] In the field of magnetic recording, in order to increase the recording density, the coercive force of recording media such as magnetic tapes is being promoted. ) is required.

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

In addition, recent attempts have been made to reduce the effects of Fe's magnetocrystalline anisotropy (adverse effect on soft magnetism) by using alloy films (Fe-C, Fe-Si, etc.) consisting of fine crystals containing Fe as the main component. There is an example in which a film with high saturation magnetic flux density and excellent soft magnetic properties was obtained by reducing the magnetic flux by miniaturization.

[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 humid and corrosive atmospheres, that is, environmental resistance.
High vibration resistance is 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 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 intolerable problem.

Furthermore, the alloy films (Fe-C, Fe-9i, 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.), it is 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 composition formula of Fex MzC.
It is represented by w, the composition ratio X is 50 to 96 atomic %, and Z is 2 to 96.
301. was 0.5 to 25, satisfying the relationship: X+z 10w=100.

The other one has a compositional formula of FexTyMzCW, where the compositional ratio X is 5θ~96 in atomic % and y is 0.1-1.
0.2 is 2-301. is 0.5 to 25, X + y +
The relationship z + 'w = 100 was satisfied.

The soft magnetic alloy film provided in this patent application has a high saturation magnetic flux density of about 18,000G in the case of partially assembled acid, has higher thermal stability than various conventional materials, and has sufficient corrosion resistance and environmental resistance. It had a sexual nature. However,
With this soft magnetic alloy film, a saturation magnetic flux density of around 20,000 G cannot be obtained, and there is a problem that it cannot be used as a magnetic head that requires particularly high recording characteristics.

The present invention solves the above-mentioned problems, has excellent soft magnetic properties, is thermally stable, can perform highly reliable glass welding, exhibits a high saturation magnetic flux density of around 20,000G, and is heat treated in a non-magnetic field. The object of the present invention is to provide a soft magnetic laminated film that can obtain sufficiently high magnetic properties even when

[Means for solving the problem] In order to solve the problem, the invention described in claim 1 has the following features:
Soft magnetic alloy layers shown by the composition formula FezMzCvy and Fe layers are alternately laminated, and the soft magnetic alloy layer is entirely composed of fine crystal grains with an average grain size of 0.08 μm or less. It is characterized by partially containing a crystalline phase of carbide of element M. However, in the above compositional formula, M is TiZ r, Hf, V , N b, Ta, Mo
, W, or a mixture thereof, and the composition ratios X, Z, and w are 50≦at.%.
x≦96.2≦2≦30.0.5≦7≦25, x+z+
It is assumed that the relationship w=100 is satisfied.

In order to solve the above-mentioned problem, the invention as set forth in claim 2 has a structure in which soft magnetic alloy layers represented by the composition formula FexTyMzCw and Fe layers are alternately laminated, and the soft magnetic alloy layer is formed by laminating the entire or average layer. It consists of 9 fine crystal grains with a grain size of 0.08 μm or less, and a part of the fine crystal grains contains a crystal phase of carbide of element M.

However, in the above compositional formula, M is Ti, Zr, Hf, V
A metal element or a mixture thereof consisting of at least one of Nb, Ta, Mo, and W, T represents at least one of Co and Ni, and the composition ratios X, )', Z, and w are 50 at %. ≦x≦96.0.1≦y≦20.2≦2≦3
It is assumed that the following relationships are satisfied: 0.0.5≦w≦25, x+Z+, -100.

In order to solve the above problem, the invention described in claim 3 has the following features:
The soft magnetic alloy layer according to claim 1 or 2 has 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 fine crystal grains contains element M. It contains a carbide crystal phase.

In order to solve the above problem, the invention described in claim 4 has the following features:
At the interface between the Fe layer and the soft magnetic alloy layer according to claim 1, 2 or 3, a concentration gradient of the constituent elements of the soft magnetic alloy layer is provided.

The present invention will be explained in more detail below.

FIG. 1 shows an embodiment of the soft magnetic laminated film of the present invention. The laminated film 1 of this embodiment has an Fe layer 3 made of pure iron on a substrate 2, and an Fe layer 3 made of pure iron, and an Fe-M-C based Or Fe-T-
It is formed by alternately laminating NC-based soft magnetic alloy layers 4. Note that a soft magnetic alloy film 4 is formed at the top of the laminated film 1.

Further, the concentration distribution in the thickness direction of the laminated film 1 is as shown in FIG.

An example of the soft magnetic alloy layer 4 is represented by the composition formula pexMzCw, and is entirely composed of fine crystal grains with an average grain size of 0.08 μm or less, and a portion of the fine crystal grains includes a crystal phase of carbide of element M. This includes: However, in the above compositional formula, M
is a metal element consisting of at least one of Ti, Zr, Hf, V, NbTa, Mo, and W, or a mixture thereof, and the composition ratios x, z, and w are 50≦x≦96 in atomic %.
．． 2≦Z≦30, 0.5≦w≦25, x + z +
It is assumed that the relationship w = 100 is satisfied.

Further, another example of the soft magnetic alloy layer 4 is FexT
It is represented by the composition formula yMzCw, and the entire average particle size is 0.0.
It consists of fine crystal grains of 8 μm or less, and includes a crystal phase of carbide of element M in a part of the fine crystal grains. However, in the above compositional formula, M is Ti, Zr, Hf, V, Nb,
A metal element or a mixture thereof consisting of at least one of Ta, Mo, and W, T represents at least one of Go and Ni, and the composition ratio X, 1/, Z + W is 50≦x≦ in atomic % 96.0.1≦y≦20.2≦2≦30.0
．． It is assumed that the relationship 5≦w≦25.80z+w=I00 is satisfied.

Methods for forming the soft magnetic laminated film include sputtering,
It is produced using an HM forming apparatus such as vapor deposition.

Existing sputtering equipment such as RF two-pole sputtering, DC sputtering, magnetron sputtering, three-pole sputtering, ion beam sputtering, and facing target sputtering can be used, but two or more sputtering equipment can be used in the same vacuum chamber. It is preferable to use an apparatus to which a target can be attached and which can produce a multilayer film without breaking the vacuum.

FIG. 3 shows an example of a film forming apparatus suitable for manufacturing the laminated film 1. In the figure, 5 is a substrate holder rotatably supported by a support shaft 6, and 7.8 is a substrate holder 5.
a cathode provided above the cathode 7.8;
A partition wall 9 is provided between them, and the entire device is housed in a vacuum container along the path shown. A substrate lO is installed on the upper surface of the substrate holder 5, a target 11 made of pure iron is provided on the lower surface of the cathode 7, and a pellet 12 such as a graphite plate and an element M such as Hf are provided on the lower surface of the cathode 8. A target 14 made of pure iron is provided with a pellet 13 made of.

In order to form the laminated film l using the apparatus having the above configuration, sputtering is performed with both cathodes 7 and 8 to generate sputtered particles from each target, and the substrate holder 5 is rotated 180 degrees at predetermined intervals. Connect the board IO to cathode 7
This is done by alternately moving both the lower side of the cathode 8 and the lower side of the cathode 8 back and forth.

Through the above operations, an Fe layer 3 is formed on the substrate IO by particles sputtered from the cathode 7, and a soft magnetic alloy layer 4 is formed by particles sputtered from the cathode 8.
is formed, and by repeating this process, a laminated film I shown in FIG. 1 is formed.

Once the laminated film 1 of a predetermined thickness is formed on the substrate l by alternately rotating the substrate holder 5, the film forming operation is stopped.

Each soft magnetic alloy layer [Fe-(T)-MC film] in the laminated film l produced in this manner exhibits some soft magnetic properties, but these soft magnetic alloy films have an amorphous phase. It contains a considerable proportion of is precipitated. By performing this heat treatment in a static magnetic field or a rotating magnetic field, excellent soft magnetic properties can be obtained. Further, this heat treatment can also be performed as a glass welding step in the manufacturing process of the magnetic head.

Note that the step of precipitating the fine crystals does not need to be performed completely, and a considerable number of fine crystals (preferably 50% or more) is required.
Since it is sufficient that the amorphous component is precipitated, there is no problem even if some of the amorphous component remains, and the remaining amorphous component does not become an obstacle to improving the properties.

In addition, as a method of adding C to the film, in addition to the method of placing a graphite pellet 12 on the target plate to form a composite target as described above and sputtering this, there is also a method of adding C to the film.
(Fe-M system or Fe-T
-M system) in an inert gas such as Ar, methane (CH
It is also possible to use a reactive sputtering method in which sputtering is performed in a gas atmosphere containing a mixture of hydrocarbon gases such as , ), etc. This reactive sputtering method allows easy control of the C concentration in the film, but when forming the Fe layer 3, it is necessary to stop the supply of CH and gas before forming the film.

The reasons for limiting the components of the soft magnetic alloy layer 4 will be described below. The reasons for limiting the components of Fe, element T, element M, and C are almost the same as in the case of Japanese Patent Application No. 1-278220.

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 5000G), it is necessary that X≧50%. Also,
In order to obtain good soft magnetic properties, it must be X596%.

Element T (ie, Co, Ni) is an element added for the purpose of adjusting magnetostriction. In the case of a Fe-MC film, when the heat treatment temperature is low, the magnetostriction becomes positive, and when the heat treatment temperature is high, the magnetostriction becomes negative. 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 when adding T, the value of y must be adjusted so that the positive magnetostriction does not increase to +10-5 or more.

Here, regarding the value of y, in Japanese Patent Application No. 1-278220, 0,1≦y≦w0 is expanded to 0,1≦y≦20 in this invention. This is because the permissible amount of y is increased to prevent the overall magnetostriction of the laminated layer H1 from increasing to the +10-5 range, even though the magnetostriction of No. 3 has a negative and large value.

Element M is necessary to improve soft magnetic properties, and also combines with C to form fine carbide crystals. In order to maintain good soft magnetic properties, it is necessary to make the two layers 2%, but if it is too large, the saturation magnetic flux density will decrease, so
It needs to be 2630%.

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 the content to 1.50.5%, but if it is too large, the saturation magnetic flux density will decrease, so it is set to 25% for each layer. There is a need.

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

The composition of the soft magnetic alloy layer 4 is mainly composed of fine crystals rich in Fe, and the addition of components that reduce the saturation magnetic flux density is limited.
The magnetic moment and Curie temperature per piece are high, and a high saturation magnetic flux density can be obtained. Also, element M
and C are included, and the metal structure is basically 0.
．． It is made up of fine crystal grains of 0.08 μm or less, and the adverse effect of magnetocrystalline anisotropy on soft magnetism is reduced, so 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,
Even when heated in the glass welding process, crystal grains do not become coarse.

In the laminated film I manufactured as described above, 20 layers 3 having a saturation magnetic flux density of 21.5 kG and soft magnetic alloy films I having a maximum saturation magnetic flux density of 18 kG are alternately laminated. In total, an extremely high saturation magnetic flux density of over 20,000G can be obtained. Also, Fe-(T)-
The MC-based soft magnetic alloy layer 4 is mainly composed of fine crystals and has excellent soft magnetic properties, and the medium crystal grains in the Fe layer are sandwiched between the soft magnetic alloy layers 4.4 from above and below. Since it is difficult to grow in the film thickness direction, the crystal grains of the 20 layer 3 are also fine, and the soft magnetic properties of the 20 layer 3 are also good.
Laminated film I has excellent soft magnetic properties.

In addition, in order to improve the soft magnetic properties of the 20 layer 3, the 20
The thickness of each layer of layer 3 is preferably 2000 Å or less. Further, there is no particular restriction on the thickness of the soft magnetic alloy layer 4, but if it is too thick compared to the 20 layer 3, it will be difficult to obtain a high saturation magnetic flux density. Furthermore, if both the 20 layer 3 and the soft magnetic alloy layer 4 are made too thin, the concentration of each component will be mixed almost uniformly in the film thickness direction due to atomic diffusion between the two layers due to heat treatment, which will reduce the effect of lamination. do not have. Note that the lower limit of the layer thickness is about 50 people.

20 layer 3 exhibits negative magnetostriction after heat treatment. Therefore, it is preferable to reduce the average magnetostriction of the entire film by adjusting the soft magnetic alloy layer 4 to have positive magnetostriction by adjusting the M and C concentration ratio or by adjusting the T# degree.

The magnetostriction can also be adjusted by changing the heat treatment temperature or the layer thickness ratio of the 20 layer 3 and the soft magnetic alloy film 4, and can be set according to various uses.

FIG. 4 shows an embodiment of the invention as set forth in claim 4, and the laminated film 21 of this embodiment is made of F made of pure iron.
This is a configuration in which a diffusion layer 25 with an intermediate concentration between the Fe layer 23 and the soft magnetic alloy layer 24 is interposed between the eFfi 23 and the soft magnetic alloy layer 24 equivalent to the previous embodiment. This diffusion layer 25 is
The concentration of added elements such as elements T, M, and C gradually decreases toward the Fe layer 23 side, and the concentration of added elements such as elements M, T, and C gradually increases toward the soft magnetic alloy layer 24 side. A concentration gradient is set so that

Therefore, in the laminated film 21 of this embodiment, the concentration distribution in the thickness direction is as shown in FIG.

The laminated film 21 having the above structure can be obtained by heat-treating the laminated film 1 having the structure shown in FIG. can.

Even in the laminated film having this structure, effects similar to those of the previously described embodiment can be obtained.

[Example (1) Film Formation] Using a 1" RF two-pole sputtering apparatus shown in FIG. 3, both the cathode equipped with a pure iron target and the cathode equipped with an iron target attached with graphite pellets and Hf pellets were simultaneously sputtered. At the same time as discharging, the substrate holder was rotated to move the substrate back and forth between the bipolar swords to form a multilayer film in which Fe layers and FeHfC layers were alternately laminated. In this multilayer film, F
The film thickness per e-layer, the film thickness per FeHf0 layer, and the number of layers thereof are shown in Table 1, and the total film thickness was 5 to 6 μm. In this laminated film, FeHfC
The composition of the film was F ess, sHfs, sC+o, e.

(2) Heat treatment and measurement After film formation, magnetic properties were measured in the as-formed state, and magnetic properties were measured after non-magnetic field heat treatment.

The results are shown in Table 1.

(Hereinafter, blank space) In the laminated films of samples a, b, and c shown in Table 1, Fe
The thickness per layer is 5 for each layer and FeHfC layer.
Although the number of participants was changed to 9, 115, and 210, all of them exhibited a high saturation magnetic flux density of 20,000 G or more and good soft magnetic properties after heat treatment. In particular, the laminated film of sample C, which had a total of 275 layers laminated with a thickness of 210A per layer, was heated at 550°C (
It shows a high magnetic permeability of 3140 after heat treatment (held for 20 minutes), and even when the heat treatment temperature is raised to 650℃, the magnetic permeability remains 2520.
It showed excellent thermal stability. However, the magnetostriction constant of the laminated film of sample C is -1.9XI (I', which is slightly negative). As shown in sample d in Table 1, λS on the order of lo-7 can be obtained.Also, adjusting the magnetostriction constant λS changes the composition of the FeHfC layer (F
This is possible by making λS of the eHfC layer more positive), and by increasing the C concentration as shown in Table 2, or by adding element T (Co or Ni), lo-7 can be similarly achieved. It is possible to set the value of λS to .

[Effects of the Invention] As detailed above, the soft magnetic alloy layer used in the laminated film of the present invention is composed of fine crystal grains containing Fe as a main component, so it is different from conventional amorphous alloy films. In contrast, even if heat treatment is performed in the absence of a magnetic field, a film exhibiting high saturation magnetic flux density and high magnetic permeability can be obtained, and the process can be simplified compared to when heat treatment is performed by applying a magnetic field. Further, the soft magnetic alloy layer contains elements M (Ti, Zr, V, Hf, N
b, Ta, M.

Components W) and C that improve soft magnetic properties are added, and the metal structure consists of fine crystal grains, which reduces the negative effect of magnetocrystalline anisotropy on soft magnetism, resulting in good soft magnetic properties. is obtained.

Furthermore, since the soft magnetic alloy layer 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-mentioned maintain the characteristics of

Furthermore, by adding elements T (Co, Ni) in addition to the above composition and adjusting 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, etc. .

That is, since the soft magnetic laminated film of the present invention is a laminated layer of a soft magnetic alloy layer having excellent soft magnetic properties as described above and an Fe layer having an excellent saturation magnetic flux density, Fe-
(It is possible to obtain an excellent saturation magnetic flux density of 20,000 G or more while maintaining the excellent soft magnetic properties and heat resistance of the TIM-C-based soft magnetic alloy film alone.

Therefore, the soft magnetic laminated film of the present invention is suitable as a material for a magnetic head for high-density recording, which requires a saturation magnetic flux density of 20,000 G or more.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a laminated film according to an embodiment of the present invention, and FIG.
The figure is a diagram showing the concentration distribution in the thickness direction of the laminated film shown in Fig. 1, and Fig. 3 is a construction diagram showing an example of a sputtering apparatus suitable for use in manufacturing the laminated film shown in Fig. 1. FIG. 4 is a sectional view showing a laminated film according to another embodiment of the present invention, and FIG. 5 is a diagram showing the concentration distribution of the laminated film shown in FIG. 4. 1. Laminated film, 2. Substrate, 3. Fe layer, 4. Soft magnetic alloy layer, 5. Substrate holder, 7, 8. Cathode, I
O...Substrate, 1 target, 12.13...Pellet, 14...Target.

Claims (1)

[Scope of Claims] (1) Soft magnetic alloy layers represented by the composition formula FexMzCw and Fe layers are alternately laminated, and the soft magnetic alloy layer is entirely composed of fine grains with an average grain size of 0.08 μm or less. A soft magnetic laminated film comprising crystal grains and containing a crystal phase of carbide of element M in a part of the fine crystal grains. However, in the above compositional formula, M is Ti, Zr, Hf, V
, Nb, Ta, Mo, and W, or a mixture thereof, and the composition ratios x, z, and w are in atomic %: 50≦x≦96 2≦z≦30 0.5≦w It is assumed that the following relationship is satisfied: ≦25 x+z+w=100. (2) Soft magnetic alloy layers represented by the composition formula FexTyMzCw and Fe layers are alternately laminated, and the soft magnetic alloy layer is entirely composed of fine crystal grains with an average grain size of 0.08 μm or less. A soft magnetic laminated film characterized in that part of the crystal grains contains a crystal phase of carbide of element M. However, in the above compositional formula, M is Ti, Zr, Hf, V
, Nb, Ta, Mo, W, T represents at least one of Co, Ni, and the composition ratio x, y, z, w is 50 atomic%. It is assumed that the following relationships are satisfied: ≦x≦96 0.1≦y≦20 2≦z≦30 0.5≦w≦25 x+z+w=100. (3) The soft magnetic alloy layer according to claim 1 or 2 has 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 fine crystal grains A soft magnetic laminated film characterized by containing a crystalline phase of carbide of element M. (4) A soft magnetic laminated film characterized in that a concentration gradient of constituent elements of the soft magnetic alloy layer is formed at the interface between the Fe layer and the soft magnetic alloy layer according to claim 1, 2 or 3. .