KR960012244B1 - Soft magnetic alloy coating - Google Patents

Abstract

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Description

Soft magnetic alloy film

The present invention relates to a soft magnetic alloy film suitable for a magnetic head or the like.

In the field of magnetic recording, in order to increase the recording density, high-magnetization of recording media such as magnetic tape is being promoted, but a high saturation magnetic flux density (Bs) is required as a soft magnetic thin film material for a magnetic head corresponding thereto.

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

In recent years, in an alloy film containing Fe as a main component (Fe-N, Fe-C, etc.), it is possible to reduce the adverse effect on the soft magnetic properties of the crystal magnetic anisotropy of Fe by miniaturizing the crystal to reduce the high saturation magnetic flux density and the soft magnetic field. There is an example of obtaining a film having excellent properties.

However, devices that combine magnetic heads tend to be miniaturized and light in weight, and are often weakened by vibration caused by movement or used in a bad environment. Therefore, the magnetic head is required to be excellent in magnetic properties and excellent in abrasion resistance to the magnetic tape, as well as high in terms of humidity and corrosion resistance, namely, environmental resistance and vibration resistance. For this reason, it is necessary to carry out glass formation by forming gaps or fitting them into the case, and the material of the magnetic head is also required to have thermal stability to withstand the high temperature of the glass welding process in the head manufacturing process.

However, in the conventional soft magnetic alloy film, the Ni-Fe film has a drawback that the soft magnetic properties deteriorate and the electrical resistance is low at high temperatures in the glass welding process.

In the Co-based amorphous film, a high saturation magnetic flux density of 13000 G or more is also obtained. To increase the saturation magnetic flux density of a conventional amorphous alloy, Ti, Zr, Hf, Nb, Ta, Mo, which is an amorphous forming element, can be obtained. It is necessary to reduce the amount of addition of W, etc., but if the amount of addition is low, the stability of the amorphous structure is lowered, and there is a problem of not being able to withstand the temperature (about 500 ° C. or more) required for glass welding. If the saturation magnetic flux density is pressed below about 9000 G, welding by low melting point glass is possible, but welding at 600 degreeC or more is difficult, and the medium to high melting point glass which is excellent in environmental resistance cannot be used.

In addition, the alloy film (Fe-N, Fe-C, etc.), which is a fine crystal containing Fe as a main component, causes crystal growth at high temperatures, and soft softness deteriorates (400 ° C is the highest for Fe-C). Also, it is hard to say that it is suitable for glass welding.

From this background, the inventors of the present application have filed a patent for a soft magnetic alloy film which solved the above problem in Japanese Patent Application Laid-Open No. 1-278220 and the like. Also, in a patent application filed on March 14, 1990, a patent application for a soft magnetic alloy film that solves the above problem is filed.

One of the soft magnetic alloy films patented in the specification of Japanese Patent Application Laid-Open No. 1-278220 is represented by Fea Mc Cd, whose composition ratio is 50 to 96 in atomic%, c to 2 to 30, and d to 0.5 to 25. , a + c + d = 100 was satisfied.

In another, the composition formula is represented by Fea Tb Mc Cd, and the composition ratio a is 50 to 96 in atomic%, b is 0.1 to 10, c is 2 to 30, d is 0.5 to 25, a + b + c + d To satisfy a relationship of = 100.

And the other is represented by Fea Tb Crc Md Ce, composition ratio a is 50 to 95 in atomic%, b is 0.1 to 10, c is 0.5 to 20, d is 2 to 25, e is 0.5 to 25, It was to satisfy the relationship that a + b + c + d + e = 100.

The soft magnetic alloy films provided in these patent applications have a high saturation magnetic flux density of some compositions of 15000 G or more, and have high thermal stability in comparison with various materials of the prior art, and thus have sufficient corrosion resistance and environmental resistance under normal use environments. Possible heat treatment temperature is the upper limit of about 700 ℃, soft magnetic deterioration at this temperature or higher. Glass welding can be performed at a temperature of 700 ° C. or lower with a normal magnetic head. However, in the case of a head having a complicated structure, for example, a head in which the erasing head and the rust ash head are integrated, a gap between the erase head and the rust ash head is formed by glass welding. Then, it is necessary to carry out glass welding of the coalescence (assembly) of both heads at the temperature which a gap laminated glass does not melt, and it is necessary to use the thing of a hot spot for a gap laminated glass. For this reason, it is preferable to perform initial gap formation at high temperature 700 degreeC or more. Therefore, a soft magnetic thin film having higher heat resistance is required.

In addition, in the soft magnetic alloy film filed in Japanese Patent Application Laid-Open No. 1-278220, the electrical resistance is about half as low as that of the conventional amorphous film, which causes a problem that the permeability of the high frequency furnace is lowered by the eddy current loss. Moreover, since Fe is a main component, there exists a possibility of causing discoloration or rust when it is used in a bad environment.

This invention is made | formed in order to solve the said subject, Comprising: It aims at providing the soft magnetic alloy film which has a high projection ratio, its characteristic is thermally stable, and has favorable corrosion resistance.

In order to solve the above problems, the present invention described in claim 1 is represented by Fea Xd Me Cf, wherein X is at least one of Al and Si, or a mixture thereof, and M is Ti, Zr, At least one of Hf, V, Nb, Ta, Mo, and W, or a mixture thereof, and the composition ratios a, c, e, and f are 50% by atom. a 95, 0.2 c 25, 2 e 25, 0.5 f While satisfying the relationship of 25, a + c + e + f = 100, the structure is basically a fine grain having an average crystal grain size of 0.08 μm or less, and part of which contains the crystal phase of the carbide of the element M. will be.

In order to solve the above problems, the invention described in claim 2 is represented by Fea Xc Crd Me Cf, wherein X is at least one of Al and Si, or a mixture thereof, and M is Ti, Zr, At least one of Hf, V, Nb, Ta, Mo, and W, or a mixture thereof, and the composition ratios a, c, d, e, and f are 50% by atomic percent. a 95, 0.2 c 25, 0.1 d 20, 2 e 25, 0.5 f While satisfying the relationship of 25, a + c + d + e + f = 100, the structure is basically a fine grain having an average grain size of 0.08 μm or less, and part of the crystal phase of the carbide of element M It is to contain.

In order to solve the above problems, the invention described in claim 3 is represented by Fea Tb Xc Me Cf, wherein T is at least one of Co and Ni, or a mixture thereof, and X is Al, Si. At least one of the elements or a mixture thereof, and M is at least one of a metal element or a mixture thereof from Ti, Zr, Hf, V, Nb, Ta, Mo, and W, composition ratio a, b, c, e, f Is 50% by atomic a 95, 0.1 b 10, 0.2 c 25, 2 e 25, 0.5 f 25, a + b + c + e + f = 100 is satisfied, and the structure is basically a fine grain having an average grain size of 0.08 µm or less, and the element M forms a carbide crystal phase in a part thereof. It is to contain.

In order to solve the above problems, the invention described in claim 4 is represented by Fea Tb Xc Crd Me Cf, wherein T is at least one of Co and Ni, or a mixture thereof, and X is Al, At least one element or a mixture thereof in Si, M is a metal element or a mixture thereof at least one of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and a composition ratio a, b, c, d, e, f is 50 atomic% 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 is satisfied, and the structure is basically a fine grain having an average grain size of 0.08 µm or less, and part of the carbide of element M It contains a crystalline phase.

In order to solve the above problems, the invention described in claim 5 is a structure in which the structure described in claims 1 to 4 is a mixed structure of fine grains and amorphous having an average grain size of 0.08 μm or less, and fine crystals. Part of the mouth contains the crystal phase of the carbide of the element M.

Hereinafter, the present invention will be described in detail again.

As a method of producing the alloy film, an alloy film is produced by a thin film forming apparatus such as sputtering or vapor deposition. As the sputtering apparatus, conventional ones such as an RF two-pole sputter, a DC sputter, a magnetron sputter, a three-pole sputter, an ion beam sputter, and an opposing target sputter can be used.

As a method of adding C to the film, a graphite pellet is placed on a target plate to form a composite target, and a sputtering method or a target containing no C (Fe-XM system or Fe-TXM system). Or Fe-TX-Cr-M), and a reactive sputtering method for sputtering in a gas atmosphere in which a hydrocarbon gas such as methane is mixed in an inert gas such as Ar can be used. Since the C concentration in the film can be easily controlled, an excellent film having a desired C concentration can be obtained.

The film thus produced contains an amorphous phase in a substantial proportion, has a low saturation magnetic flux density and insufficient soft magnetic properties. Thus, microcrystals are precipitated by heat treatment at 400 占 폚 or higher. Although the soft magnetic properties are good even if the heat treatment is carried out in a magnetic field, excellent magnetic properties are obtained by performing in a static magnetic field or a rotational simulation. This heat treatment can be performed in combination with the glass welding step in the manufacturing process of the magnetic head.

In addition, the precipitation process of the microcrystals does not need to be carried out completely, and a large number of microcrystals (preferably 50% or more) should be precipitated, so that even if some of the amorphous components remain, there is no problem. It is not an obstacle.

The reason for limiting the above components is described below.

Fe is a main component and is an element having magnetic properties. To obtain a saturation magnetic flux density of at least ferrite (Bs 5000G): a 50at% is required. In addition, in order to obtain good soft magnetic properties, It must be 95at%.

The element T (that is, Co, Ni) is an element added for the purpose of ultraviolet adjustment. In the film without the addition of the element T, ultraviolet light becomes a positive value when the heat treatment temperature is low or when the amount of addition of Si is small. On the contrary, ultraviolet light becomes a negative value when the heat treatment temperature is high or when the amount of addition of Si is large. The heat treatment temperature at which the ultraviolet rays become zero also depends on the temperature of the elements M and C. However, when there is a need to increase the amount of Si and increase the heat treatment temperature (glass welding temperature), since ultraviolet rays become negative, by adding elements T (that is, Co and Ni) having an effect of making ultraviolet light positive, Ultraviolet can be adjusted to zero. In addition, when the heat treatment temperature and the amount of Si added are appropriate, the addition of the element T is not particularly necessary. Just the amount of the element T is to be b10at% so as not to greatly definition-visible +10 ^-5 or more.

Elements M (i.e., Ti, Zr, Hf, V, Nb, Ta, W) are necessary to improve soft magnetic properties, and combine with C to form carbide microcrystals. The fine particles of this carbide act to hinder the growth of the crystal containing Fe as a main component and high heat resistance is obtained.

To maintain good soft magnetic properties, e It is necessary to set it to 2at%. However, if too much, the saturation magnetic flux density is lowered and soft magnetic properties are lowered. It is necessary to set it to 25at%.

C is necessary to improve soft magnetic properties and to improve heat resistance, and C is combined with element M to form carbide microcrystals. To maintain good soft magnetic properties and thermal stability, f It is necessary to set it to 0.5 at%. Too much, however, results in a decrease in saturation magnetic flux density and a decrease in soft magnetic properties. It is necessary to set it to 25at%.

The reason for the limitation of the components of Fe, the element T, and the elements M and C in the above description is almost the same as in the case of Japanese Patent Application No. 1-27822.

Element X (ie, Al, Si) lowers the crystal magnetic anisotropy energy of fine crystals containing Fe as a main component and preserves the soft magnetic properties even when the crystal size grows to some extent. It is possible.

Moreover, it has the effect | action which raises electric resistance and improves the fall of the high frequency permeability by eddy current loss.

In order to achieve the above effect, at least c It is necessary to set it to 0.2at%. However, if the content of element X is too high, the saturation magnetic flux density decreases, so c It is necessary to set it to 25at%.

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

The fine crystals of the carbide of the element M are uniformly dispersed in the film, thereby preventing the Fe crystals from growing and coarsening by heat treatment and losing soft magnetic properties. However, when the grain size of Fe grows and is large, the adverse effect of crystallite anisotropy is increased so that the soft magnetic properties deteriorate, but the microcrystals of the carbide of element M act as a barrier to the grain growth of Fe, thereby preventing the deterioration of the soft magnetic properties. .

In the present invention, the addition of the element X (that is, Al, Si) lowers the crystal magnetic anisotropy energy of the individual crystals containing Fe as a main component, and maintains the soft magnetic properties even if the crystal grows to some extent by high temperature heat treatment. Have

In addition, since the metal structure is basically microcrystals of 0.08 µm or less, the thermal stability is superior to that of the amorphous material, and the added element can be reduced and the saturation magnetic flux density can be increased.

In the soft magnetic alloy film, since the composition mainly contains Fe-rich crystals and the addition of a component that lowers the saturation magnetic flux density is limited, the magnetic moment and curie temperature per iron atom are higher than those in the amorphous state. , High saturation magnetic flux density is obtained. In addition, while the elements M and C are contained, the metal structure is made of fine grains, and the adverse effect on the soft magnetic properties due to the magnetic anisotropy is reduced, and thus the good soft magnetic properties are obtained. In addition, even if the carbide of the element M precipitates and suppresses the growth of grains containing Fe as a main component, the grains do not coarsen even when heated in the glass welding step. And since a specific amount of Cr is added, corrosion resistance improves and it is excellent in environmental resistance.

In addition, the addition of the elements X (Al, Si) increases the electrical resistance, thereby reducing the eddy current loss at the high frequency, thereby increasing the high frequency permeability.

Example

(1) the tabernacle

The alloy film of the composition shown to the 1st table | surface of a later stage was formed using the RF bipolar sputter apparatus.

The used target was sputtered in an Ar gas atmosphere using a composite target configured by appropriately arranging various pellets such as Si, Al, Co, Ta, and graphite on the Fe target to form a thin film having a thickness of 5 to 6 μm. .

(2) heat treatment

After film formation, annealing was performed by storing the solution at 650 ° C. for 20 minutes in the magnetic field.

(3) measurement

Regarding the alloy film (the alloy film according to the invention applied for in Japanese Patent Application Laid-Open No. 1-278220) containing no element X formed by sputtering the alloy film produced as described above, after the magnetic field annealing The saturation magnetic flux density (Bs), the super magnetic permeability (μ, at 1 MHz), the coercive force (Hc), the ultraviolet constant (λ) and the specific resistance (ρ, μΩ · cm) were measured. The above result is shown to a 1st table | surface.

TABLE 1

Comparative Example a of Sample 1 in Table 1 is that the inventor first applied for a patent. All of the alloy films b to k according to the present invention have a higher resistivity (electrical resistance) than a, and magnetic properties (saturated magnetic flux density, ultra-permeability, coercivity ultraviolet constant) are also equal to or higher than a. have.

The thermal stability (heat resistance) of the soft magnetic properties of the alloy film prepared by the above method is shown in Table 2 in comparison with the alloy film filed in Japanese Patent Application Laid-Open No. 1-278220.

TABLE 2

It can be seen that the alloy film of the present invention exhibits higher thermal stability than the alloy film shown in Table 2 as a comparative example. Moreover, the specific resistance which heat-processed at 750 degreeC showed the numerical value about 3 times higher than the specific resistance of the comparative example.

As described above, the present invention is a soft magnetic alloy film mainly containing fine grains containing Fe as a main component, and high saturation magnetic flux density is obtained because the addition of a component that lowers the saturation magnetic flux density is limited. As a result, a magnetic head having high recording characteristics can be provided.

In addition, unlike conventional amorphous alloy films, a film exhibiting a high permeability can be obtained even if heat treatment is performed in a magnetic field, and a process such as glass welding in the manufacture of a magnetic head can be simplified rather than the case of heat treatment under a magnetic field. Can be.

Moreover, while the components which improve the soft magnetic properties of elements M (Ti, Zr, Hf, V, Nb, Ta, Mo, W) and C are added, the metal structure becomes fine grains, and the soft magnetic particles by crystal magnetic anisotropy By reducing the adverse effect on frost, good soft magnetic properties are obtained.

In addition, fine grains form, the added element M forms C and carbides, and the carbides are uniformly dispersed in the film, thereby preventing the growth of microcrystals containing Fe as a main component by heat treatment. In other words, as the crystal grows, the adverse effect of crystal magnetic anisotropy increases, thereby preventing soft magnetic deterioration.

In addition to the above-mentioned composition, the addition of the element X (Al, Si) decreases the crystal anisotropy energy of the individual crystals containing Fe as a main component, so that soft magnetism can be maintained even if the crystal becomes large to some extent, and high temperature. Withstands heat treatment at By this fact, highly reliable medium to high melting point glass can be used as the welded glass, and at the same time, it can withstand the heat history in the processing method of the magnetic head of a complicated structure requiring multi-step glass welding.

In addition, when Si or Al is added, the electrical resistance is high, the eddy current loss is decreased at high frequency, and the permeability of the high frequency can be increased.

By adding the elements T (Co, Ni), the ultraviolet rays can be adjusted to prevent deterioration of the soft magnetic properties due to various distortions in the magnetic head manufacturing process.

In addition, by adding a specific amount of Cr to the above components, the Fe-based alloy is characterized in that discoloration or rust does not occur even in a bad environment excellent in corrosion resistance.

Claims (8)

The composition formula is represented by Fea Xd Me Cf, X is at least one element selected from Al, Si or a mixture thereof, and M is at least one selected from Ti, Zr, Hf, V, Nb, Ta, Mo, W A metal element or a mixture thereof; composition ratios a, c, e, and f are 50 a 95, 0.2 c 25, 2 e 25, 0.5 f 25, a + c + e + f = 100 is satisfied, and the structure is basically composed of fine grains having an average grain size of 0.08 µm or less, and a part thereof contains the crystal phase of the carbide of element M. Soft magnetic alloy film, characterized in that. The composition formula is represented by Fea Xc Crd Me Cf, X is one or more elements selected from Al, Si or mixtures thereof, and M is 1 selected from Ti, Zr, Hf, V, Nb, Ta, Mo, W At least two or more metal elements or mixtures thereof; composition ratios a, c, d, e, and f are 50% by atom a 95, 0.2 c 25, 0.1 d 20, 2 e 25, 0.5 f While satisfying the relationship of 25, a + c + d + e + f = 100, the structure is basically composed of fine grains having an average grain size of 0.08 µm or less, and part of the crystal phase of the carbide of element M A soft magnetic alloy film containing a. The composition is represented by Fea Tb Xc Me Cf, T is at least one metal element selected from Co, Ni or a mixture thereof, X is at least one element selected from Al, Si or mixture thereof, M is Ti, Zr, Hf, V, Nb, Ta, Mo, W is one or more metal elements or mixtures thereof, and the composition ratios a, b, c, e, f are 50% by atomic percent a 95, 0.1 b 10, 0.2 c 25, 2 e 25, 0.5 f While satisfying the relationship of 25, a + b + c + e + f = 100, the structure is basically composed of fine grains having an average grain size of 0.08 µm or less, and part of the crystal phase of the carbide of element M A soft magnetic alloy film comprising: The composition is represented by Fea Tb Xc Crd Me Cf, T is at least one metal element selected from Co, Ni, or a mixture thereof, X is at least one element selected from Al, Si, or a mixture thereof, and M is Ti , Zr, Hf, V, Nb, Ta, Mo, W, at least one metal element or a mixture thereof, and the composition ratios a, b, c, d, e, f are 50% by atom 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 is satisfied, and the structure is basically composed of fine grains having an average grain size of 0.08 µm or less, and part of the carbide of element M A soft-crystalline alloy film containing a crystalline phase. The soft magnetic alloy film according to claim 1, wherein the structure is a structure in which fine grains and amorphous particles having an average grain size of 0.08 µm or less are mixed, and a part of the fine grains contains a crystalline phase of the carbide of element M. . 3. The soft magnetic alloy film according to claim 2, wherein the structure is a structure in which fine grains and amorphous particles having an average grain size of 0.08 mu m or less are mixed, and a part of the fine grains contains a crystalline phase of the carbide of element M. . 4. The soft magnetic alloy film according to claim 3, wherein the structure is a structure in which fine grains and amorphous particles having an average grain size of 0.08 mu m or less are mixed, and a part of the fine grains contains a crystalline phase of the carbide of element M. . 5. The soft magnetic alloy film according to claim 4, wherein the structure is a structure in which fine grains and amorphous particles having an average grain size of 0.08 mu m or less are mixed, and a portion of the fine grains contains a crystalline phase of carbide of element M. .