KR101646653B1 - Crystalline alloy and method for manufacturing the same - Google Patents

Abstract

The present invention provides a method for producing a crystalline alloy having an amorphous forming ability and a thermal stability remarkably superior to an amorphous state, and a method for heat treatment of an amorphous alloy therefor. An amorphous alloy or a nanocrystalline alloy containing a metal element having an amorphous forming ability is pressed while maintaining the amorphous alloy or the nanocrystalline alloy in a temperature range not lower than the glass transition temperature (Tg) of the amorphous alloy or the crystallization start temperature (Tx) A first shrinking step; And secondarily shrinking the plurality of amorphous alloys or nanocrystalline alloys by pressurizing the amorphous alloy or the nanocrystalline alloy while maintaining the temperature within a range of 0.7 to 0.9 times the melting temperature (Tm) of the amorphous alloy or nano-crystalline alloy for a predetermined period of time; The present invention also provides a method for producing a crystalline alloy.

Description

Crystalline alloy and method for manufacturing same

The present invention relates to a crystalline alloy and a method of manufacturing the same, and more particularly, to a method of manufacturing a crystalline alloy including a heat treatment of an amorphous alloy including a metal element having amorphous forming ability and a crystalline alloy therefrom.

The sputtering process refers to a technique of forming a thin film on the surface of a base material by colliding argon ions or the like with a negative voltage at high speed to release the target atoms and supplying the target atoms to the base material. Such a sputtering process is also used in the field of semiconductor manufacturing process, the manufacture of fine devices such as MEMS, as well as the coating formation for the improvement of wear resistance of various tools, molds, and automobile parts.

When the amorphous thin film or the nanocomposite thin film containing the amorphous phase is produced by sputtering, a target made of amorphous can be used. The amorphous target may be formed of a multi-metallic metal alloy having high amorphous forming ability, and the dissimilar metal elements separated from the amorphous target may form an alloy thin film having an amorphous phase on the surface of the base material.

However, an amorphous alloy system having a capability of forming a bulk amorphous material having a sputtering target size that is used industrially has not been reported. To solve this problem, an amorphous powder is prepared, and then a high pressure of 600 MPa or more is applied. Technology is being tried.

On the other hand, even in a high-density amorphous target produced under high pressure, the temperature increases due to ion collision in the sputtering process, and the tissue near the surface of the target can be changed due to such temperature increase. That is, due to the characteristics of the thermally unstable amorphous phase, when the temperature of the target is increased, local crystallization can proceed on the surface of the target. This local crystallization can cause volume change and structural relaxation of the target, which can increase the target's brittleness and result in the target being easily destroyed during the sputtering process. If the target is destroyed during the process, it will cause a serious problem in the production of the product, so it is very important to secure a stable target that does not cause such destruction during the sputtering process.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an amorphous sintered body excellent in thermal stability, The present invention also provides a method of producing the same. However, these problems are exemplary and do not limit the scope of the present invention.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a plurality of amorphous alloys or nanocrystalline alloys containing a metal element having amorphous forming ability; The first shrinkage of the amorphous alloy or the nanocrystalline alloy by pressing the amorphous alloy or the nanocrystalline alloy while maintaining the amorphous alloy or the nanocrystalline alloy at a temperature not higher than the glass transition temperature (Tg) of the amorphous alloy or the nanocrystalline alloy at the crystallization start temperature (Tx) ; And secondarily shrinking the plurality of amorphous alloys or nanocrystalline alloys by pressurizing the amorphous alloy or the nanocrystalline alloy while maintaining the temperature within a range of 0.7 to 0.9 times the melting temperature (Tm) of the amorphous alloy or nano-crystalline alloy for a predetermined period of time; The present invention also provides a method for producing a crystalline alloy.

In the above-described method for producing a crystalline alloy, the amorphous alloy or the nanocrystalline alloy preferably contains 58 atom% to 78 atom% of Zr; 4 atom% to 26 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co may be composed of 4 atom% to 20 atom%.

In the above-described method for producing a crystalline alloy, the amorphous alloy or the nanocrystalline alloy contains 62 atom% to 76 atom% of Zr; Al is less than 10 atomic% (more than 0 atomic%); 2 atom% to 20 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is 6 atomic% to 27 atomic%.

The first shrinking of the method of manufacturing the crystalline alloy; And the second contraction, the pressurization may be performed under a pressure in the range of 10 MPa to 50 MPa.

The method of manufacturing the crystalline alloy may further include raising the plurality of amorphous alloys or the nanocrystalline alloy between the first shrinking step and the second shrinking step.

In the method of producing the crystalline alloy, the first shrinking may include controlling the porosity of the amorphous alloy or the nanocrystalline alloy to 1% or less.

In the method of manufacturing the crystalline alloy, the second shrinking may include controlling the porosity of the amorphous alloy or the nanocrystalline alloy to 0.1% or less.

In the method of manufacturing the crystalline alloy, the second shrinking may include crystallizing a plurality of the amorphous alloys or the nanocrystalline alloy so that the average grain size of the amorphous alloy is in the range of 0.1 탆 to 5 탆.

In the method of manufacturing the crystalline alloy, the amorphous alloy or the nanocrystalline alloy may have at least one shape selected from the group consisting of a foil, a powder, a block, and a rod.

A crystalline alloy according to another aspect of the present invention is realized by the above-described manufacturing method, and has a Zr of 58 atom% to 78 atom%; 4 atom% to 26 atom% Cu; At least one selected from Fe, Ni and Co is 4 atom% to 20 atom%.

A crystalline alloy according to another aspect of the present invention is realized by the above-described manufacturing method, and has a Zr of 62 atom% to 76 atom%; Al is less than 10 atomic% (more than 0 atomic%); 2 atom% to 20 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is composed of 6 atom% to 27 atom%.

A target for sputtering according to another aspect of the present invention is realized by the above-described manufacturing method, and has a Zr of 58 atom% to 78 atom%; 4 atom% to 26 atom% Cu; At least one selected from Fe, Ni and Co is 4 atom% to 20 atom%.

A target for sputtering according to another aspect of the present invention is realized by the above-described manufacturing method, and has a Zr of 62 atom% to 76 atom%; Al is less than 10 atomic% (more than 0 atomic%); 2 atom% to 20 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is composed of 6 atom% to 27 atom%.

According to the embodiments of the present invention, it is possible to realize a crystalline alloy having a significantly improved thermal / mechanical stability at a relatively low cost. In addition, the thermal / mechanical stability of the target is greatly improved, and the target is not suddenly broken during the sputtering process, so that the sputtering process can be performed stably. In addition, since it has a very uniform microstructure, it has an effect of narrowing the compositional deviation between the target composition and the thin film composition due to the difference of the sputtering yield of the multi-component constituting the target, There is an effect that can be secured. Of course, the scope of the present invention is not limited by these effects.

1 is a diagram illustrating a concept of implementing a crystalline alloy by subjecting an amorphous alloy and / or a nanocrystalline alloy to heat treatment in a method of manufacturing a crystalline alloy according to an embodiment of the present invention.
FIG. 2 is a photograph of a Vickers-pressure particle test on a crystalline alloy having a composition disclosed in Examples of the present invention. FIG.
Fig. 3 is a result of observing the microstructure of the crystalline alloy having the composition disclosed in the embodiments of the present invention.
4A and 4B are photographs of a target surface observed after sputtering of a target for sputtering according to some embodiments of the present invention.
FIGS. 5 and 6 show an X-ray diffraction pattern of an amorphous thin film and a nitride thin film formed by a sputtering process using a target for sputtering according to some embodiments of the present invention.
7 is an X-ray diffraction pattern of a thin film formed by a sputtering process using a sputtering target (Example 46, Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 ) according to an embodiment of the present invention.
Figures 8 and 9 are the results of a lubricant friction test of a nanostructure composite thin film according to some embodiments of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

The film referred to herein may also be referred to as a thin film depending on the thickness of the film. For example, the nitride film may be referred to as a nitride film in some cases, and the amorphous film may be referred to as an amorphous film in some cases.

The crystalline alloy according to the present invention is characterized in that an amorphous alloy or a nanocrystalline alloy composed of three or more metal elements having an amorphous glass forming ability is heated to a crystallization start temperature (Tx) of the amorphous alloy or a nanocrystalline alloy at a melting temperature (Tm) Lt; 0 > C. In the case of such an amorphous alloy, crystallization takes place in the heating process, followed by grain growth. In the case of the nanocrystalline alloy, nanocrystalline growth occurs. At this time, the heating conditions can be controlled so that the mean grain size of the crystal grains of the crystalline alloy ranges from 0.1 mu m to 5 mu m, strictly from 0.3 mu m to 2.5 mu m.

In the present invention, the crystallization initiation temperature is a temperature at which an alloy in an amorphous state starts to crystallize, and has an inherent value according to a specific alloy composition. Therefore, the crystallization initiation temperature of the nanocrystalline alloy may be defined as the temperature at which the amorphous alloy having the same composition as the nanocrystalline alloy starts to crystallize. [0043] The amorphous alloy has substantially no specific crystal structure and the X- May refer to a metal alloy having an image in which a broad peak is observed in a wide angle range without showing a sharp peak at a Bragg angle. The nanocrystalline alloy may mean a metal alloy having an average grain size of less than 100 nm.

The amorphous alloy having the amorphous forming ability according to the present invention is composed of, for example, three or more elements, and the difference in atomic radius between the main elements is as large as 12% or more, and the heat of mixing between the main elements is negative The value of < / RTI >

 An alloy composed of three or more metal elements having an amorphous forming ability according to an embodiment of the present invention includes Zr of 58 atom% to 78 atom%; 4 atom% to 26 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co may be composed of 4 atom% to 20 atom%.

An alloy composed of three or more metal elements having an amorphous forming ability according to another embodiment of the present invention has a Zr of 62 atom% to 76 atom%; Al is less than 10 atomic% (more than 0 atomic%); 2 atom% to 20 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is 6 atomic% to 27 atomic%.

Such a crystalline alloy according to the present invention has excellent thermal stability compared to an amorphous alloy of the same composition. That is, in the case of an amorphous alloy, due to thermal instability, locally partial crystallization occurs due to heat energy transferred from the outside, and nanocrystals are locally formed. This local crystallization is weakened by the structural relaxation of the amorphous alloy and the fracture toughness is reduced.

However, alloys whose grain size is controlled through crystallization and / or grain growth from amorphous alloys or nanocrystalline alloys such as the crystalline alloys according to the present invention do not show large changes in microstructure even when heat is applied from the outside, The amorphous alloy or the nanocrystalline alloy does not exhibit destruction due to thermal and mechanical instability.

Such a crystalline alloy according to the embodiments of the present invention can be successfully applied to fields requiring thermal stability, and can be applied to a sputtering target as an example.

An amorphous alloy target composed of a plurality of metal elements having an amorphous forming ability may be used to form an amorphous thin film or a nanostructure composite thin film through sputtering. In the case of the sputtering target, the ions accelerated from the plasma during the process continuously collide with each other, so that the temperature of the sputtering target inevitably rises during the process. When the sputtering target is made of amorphous material, local crystallization at the target surface due to a rise in temperature may proceed during the sputtering process, and this local crystallization may increase the brittleness of the target, which may result in the target being easily broken during the sputtering process.

Also, in the sputtering target produced by the casting method, i) the equilibrium solidification structure of the alloy system is very weak because it is composed of an intermetallic compound having a high brittleness, and ii) the grain size of the constitution is very large, .

On the other hand, the crystalline alloy according to the present invention has a microstructure in which crystal grains having a specific size range controlled by heat treatment have a uniformly distributed microstructure, so that the thermal / mechanical stability is greatly improved and the local temperature , And thus the mechanical instability as described above does not appear. Therefore, in the case of the crystalline alloy target of the present invention, sputtering can be used to stably form an amorphous thin film or a nanostructure composite thin film.

Hereinafter, a method of manufacturing an alloy target for sputtering using the crystalline alloy of the present invention will be described as an example.

The alloy for sputtering using the crystalline alloy of the present invention may be one casted in a size and shape similar to the sputtering target in which the amorphous alloy or the nanocrystalline alloy is actually used. The amorphous alloy or the nanocrystalline alloy thus cast may be heat- A crystalline alloy target can be produced by crystallizing or growing crystal grains through annealing.

As another method, a plurality of amorphous alloys or nanocrystalline alloys may be prepared, and the plurality of amorphous alloys or nanocrystalline alloys may be thermally press-bonded to each other to produce a sputtering target. The annealing process or the thermal pressurization may be performed at a temperature not higher than the glass transition temperature (Tg) of the amorphous alloy and not higher than the crystallization start temperature (Tx), and the amorphous alloy or the nanocrystalline alloy may undergo the plastic deformation Sintering proceeds, and secondary sintering and grain growth are performed in a temperature range that is not lower than the crystallization start temperature of the amorphous alloy or the nano-crystalline alloy, and less than the melting temperature. The crystallization initiation temperature is defined as the temperature at which an alloy having a specific composition begins to transition from an amorphous state to a crystalline state.

The plurality of amorphous alloys or nanocrystalline alloys may be, for example, amorphous alloy powders or nanocrystalline alloy powders. The agglomerates of these alloy powders are pressed and sintered in a sintered metal mold and bonded to each other, whereby a shape and size approximate to an actual target can be produced. In this case, in the pressure sintering, the first sintering proceeds at a temperature equal to or higher than the glass transition temperature (Tg) of the amorphous alloy at the crystallization start temperature (Tx) or less, and at the temperature range not lower than the crystallization start temperature of the amorphous alloy or the nano- Secondary sintering and grain growth are performed. During the heating process, the agglomerates of the amorphous alloy powder or the agglomerates of the nanocrystalline alloy powder are bonded to each other by diffusion to cause crystallization and / or grain growth. At this time, the time and / or temperature and the like are controlled so that the size of the crystal grains has a specific range. Thus, the finally crystallized or grain-grown alloy may have a grain size of the alloy of 5 탆 or less, for example, in the range of 0.1 탆 to 5 탆, strictly 0.3 탆 to 2.5 탆.

At this time, the amorphous alloy powder or the nanocrystalline alloy powder may be one produced by automizing. Specifically, a molten metal in which three or more metal elements having amorphous forming ability are dissolved is prepared, and an inert gas such as an argon gas is sprayed onto the molten metal while the molten metal is sprayed, thereby rapidly cooling the molten metal to form an alloy powder. The amorphous alloy or the nanocrystalline alloy prepared in plurality may be an amorphous alloy ribbon and / or a nanocrystalline alloy ribbon in the form of a foil. After the plurality of such ribbons are laminated, the target can be formed by thermal pressurization in a temperature range from the crystallization start temperature to the melting temperature in the composition of the alloy ribbon. In this case, the amorphous alloy ribbon laminate and / or the nanocrystalline alloy ribbon laminate undergo crystallization and / or grain growth during bonding due to interdiffusion between the ribbons. Meanwhile, the lamination interface between the stacked alloy ribbons in this process can be extinguished by mutual diffusion.

At this time, the amorphous alloy ribbon or the nanocrystalline alloy ribbon may be one produced by a rapid solidification process such as melt spinning. Specifically, a molten metal in which three or more metal elements having amorphous forming ability are dissolved is prepared, and the molten metal is put on a surface of a roll rotating at a high speed to rapidly solidify the amorphous alloy or nanocrystalline alloy in a ribbon shape.

As another example, a plurality of prepared amorphous alloys or nanocrystalline alloys may be amorphous alloy castings or nanocrystalline alloy castings. At this time, the amorphous alloy casting material or the nanocrystalline alloy casting material may have a rod shape or a plate shape. In this case, in the laminate in which a plurality of amorphous alloy casting materials are laminated or a nano-crystalline alloy casting material is laminated during the heat-pressurizing treatment, crystallization and / or grain growth is caused do. At this time, the amorphous alloy casting material or the nanocrystalline alloy casting material may be formed by using a pressure difference between the inside and the outside of a mold such as copper having high cooling ability And may be manufactured by a suction method or a pressurizing method in which the molten metal is injected into the mold. For example, a molten metal in which three or more metal elements having amorphous forming ability are prepared is prepared by a copper mold casting method, and the molten metal is injected into the copper mold at a high speed through a nozzle by pressurizing or sucking the molten metal and rapidly solidified to form amorphous Alloy castings or nanocrystalline alloy castings can be produced.

In the case of alloy ribbons or alloy castings, the final crystallized alloy, like in the case of alloy powders, is adjusted such that the grain size of the alloy is in the range described above.

Hereinafter, embodiments are provided to facilitate understanding of the present invention. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention, but the present invention is not limited by the following examples.

Heat treatment method

1 is a diagram illustrating a concept of implementing a crystalline alloy by applying heat treatment to an amorphous alloy and / or a nanocrystalline alloy in a method of manufacturing a crystalline alloy according to an embodiment of the present invention. First, referring to FIG. 1 , The sintering and / or heat treatment of the amorphous alloy or the nanocrystalline alloy includes preparing a plurality of amorphous alloys or nanocrystalline alloys containing a metal element having an amorphous forming ability; The temperature of the amorphous alloy or the nanocrystalline alloy in the temperature range of the glass transition temperature (Tg) of the amorphous alloy or the nanocrystalline alloy is not more than the crystallization start temperature (Tx) (that is, the temperature range of the supercooled liquid phase region A first heat treatment step (1 & cir &) for holding for a predetermined time under a predetermined pressure, for example, a pressure of tens of MPa to several hundreds of MPa; And the plurality of amorphous alloys or nanocrystalline alloys at a temperature ranging from 0.7 to 0.9 times the melting temperature (Tm) of the amorphous alloy or the nanocrystalline alloy under a predetermined pressure, for example, at a pressure of tens of MPa to several hundred MPa And a second heat treatment step (4 & cir &) for holding for a predetermined period of time.

The first heat treatment step (region (1)) can be performed while maintaining a constant temperature in a temperature range not lower than the glass transition temperature (Tg) and the crystallization start temperature (Tx), for example. As another example, the first heat treatment step (region 1) may be performed at a temperature which is variable in a temperature range not lower than the glass transition temperature (Tg) and the crystallization start temperature (Tx).

Can be performed while maintaining the temperature at a constant temperature in a range of 0.7 to 0.9 times the melting temperature (Tm) of the second heat treatment step (4), for example, the amorphous alloy or the nanocrystalline alloy. In another example, the second heat treatment step (zone 4) may be performed at a temperature varying from 0.7 to 0.9 times the melting temperature (Tm) of the amorphous alloy or the nanocrystalline alloy.

According to one embodiment of the present invention, sintering and / or heat treatment under very high pressure, such as 600 MPa, as in the prior art, and sintering under a pressure of tens of MPa to several hundred MPa, for example under a pressure of 20 MPa And / heat treatment can be carried out, so that it is advantageous that high-pressure equipment is not used. The present inventors have found that sintering and / or heat treatment is possible even when the first heat treatment step and / or the second heat treatment step are performed under a pressure ranging from 10 MPa to 50 MPa.

The first heat treatment step (1) includes controlling the porosity of the amorphous alloy or the nanocrystalline alloy to 1% or less.

Wherein the second heat treatment step (④ zone) includes a step in which a plurality of the amorphous layer-to-layer interfaces of the plurality of amorphous alloys or the nanocrystalline alloy are controlled to have a porosity of 0.1% or less, Crystallized so that the amorphous alloy or the nanocrystalline alloy has an average grain size in the range of 0.1 mu m to 5 mu m.

Meanwhile, the sintering and / or heat treatment of the amorphous alloy or the nanocrystalline alloy may include heating the plurality of amorphous alloys or the nanocrystalline alloy between the first heat treatment step and the second heat treatment step (zone 2, zone 3); . The first heating temperature zone (2) includes a temperature range immediately above the crystallization starting temperature (Tx) of the amorphous alloy or the nanocrystalline alloy. The second heating temperature zone (3) includes an amorphous alloy or a nanocrystalline alloy Is carried out in a temperature range of 0.6 times or less of the melting temperature (Tm).

In summary, the sintering and / or heat treatment of the amorphous alloy or the nanocrystalline alloy described above can be carried out in the temperature range of 0.7 _Tm or more and 0.9 _Tm or less ( _Tm is the melting temperature of the amorphous alloy) Lt; RTI ID = 0.0 > shrinkage < / RTI > By the primary shrinkage, the amorphous state of the sintered body is realized to be 1% or less, and the crystalline state is realized in which the porosity of the sintered body is 0.1% or less due to the secondary shrinkage. The multistage sintering and / or heat treatment process can be applied not only to the amorphous foil described above but also to amorphous solid (amorphous powder, nanocrystalline powder, amorphous rod, amorphous foil) having any arbitrary shape.

A plurality of amorphous alloys can be sintered in the superplastic section to achieve a sintered density of 99% or more through the first heat treatment step (zone 1). However, the cohesive force due to mutual diffusion between the foil and the powder particles may be deteriorated. Generally, a high load of 700 MPa or more is required in order to secure sintering and bonding force in the superplastic section by using amorphous powder, resulting in a disadvantage that the manufacturing cost is greatly increased. The inventors of the present invention have found that by introducing a two-step heat treatment process of a first heat treatment stage (zone 1) and a second heat treatment stage (zone 4), crystal grain control technology is obtained through the superplasticity and crystallization behavior of the amorphous alloy, The present invention provides a method for producing a crystalline alloy. On the other hand, cracks occurred in the alloys after passing through the first heating step (the zone 2) and the second heating step (the third zone), which are the middle stages of the heat treatment process, due to the mutual diffusion between the amorphous alloys in powder or foil form It is understood that the bonding force is still low.

According to the present invention, the amorphous alloy can be heat-treated at a relatively low cost, or the plurality of amorphous alloys can be heat-treated at the same time as the sintering / bonding, and the thermal / mechanical stability can be greatly improved.

Crystalline target alloy composition

Meanwhile, the present inventors propose a composition range of an alloy capable of realizing a target for sputtering by the above-mentioned heat treatment method.

Table 1 and Table 2 shows some embodiments of the composition of a sputtering target for the amorphous-forming ability, and the average grain size, the glass transition temperature (T _g) and the crystallization starting temperature (T _x) in accordance with the present invention.

Example Furtherance Formability Grain size
( 탆) T _g (° C) T _x (° C) Example 1 Zr _58.9 Ni ₇ Co ₉ Cu _25.1 0.5 0.58 391.88 416.22 Example 2 Zr _61.8 Ni ₆ Co _7.5 Cu _24.7 0.5 0.54 380.82 403.19 Example 3 Zr _61.8 Co _7.5 Fe ₆ Cu _24.7 0.5 ↓ 0.72 386.66 409.98 Example 4 Zr _62.4 Ni ₆ Co _8.75 Cu _22.85 0.5 0.88 379.24 401.15 Example 5 Zr _62.8 Ni ₄ Co ₅ Fe ₄ Cu _24.2 0.5 0.77 363.97 406.4 Example 6 Zr _62.9 Ni ₆ Co _10.5 Cu _20.6 0.5 0.64 345.52 395.07 Example 7 Zr _64.5 Ni ₅ Co ₅ Fe ₅ Cu _20.5 0.5 0.88 380.22 402.23 Example 8 Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ 0.5 2.03 373.5 399.39 Example 9 Zr _65.9 Ni ₃ Co ₁₀ Cu _21.1 One 0.69 367.22 389.73 Example 10 Zr _67.5 Ni ₅ Co ₄ Fe ₅ Cu _18.5 0.5 ↓ 0.75 356.79 392.29 Example 11 Zr _68.5 Co ₅ Fe ₅ Cu _21.5 0.5 0.79 329.05 387.87 Example 12 Zr _69.2 Co _7.5 Fe ₃ Cu _20.3 0.5 0.77 352.07 384.73 Example 13 Zr _69.6 Ni ₄ Co ₁₆ Cu _10.4 0.5 ↓ 0.68 344.25 384.85 Example 14 Zr _69.86 Co ₁₂ Cu _18.14 0.5 ↓ 0.54 360.12 377.34 Example 15 Zr _70.1 Ni ₁ Co ₁₀ Cu _18.9 One 0.55 352.04 377.9 Example 16 Zr _70.2 Ni ₁ Co ₁₁ Cu _17.8 0.5 2.13 349.29 377.67 Example 17 Zr _70.4 Ni ₃ Co ₆ Cu _20.6 One 0.96 349.76 383.62 Example 18 Zr _70.9 Ni ₃ Co ₄ Cu _22.1 0.5 0.87 338.74 366.44 Example 19 Zr _71.1 Ni ₃ Co ₃ Cu _22.9 0.5 0.85 338.41 347.78 Example 20 Zr _71.3 Co ₇ Fe _2.4 Cu _19.3 0.5 ↓ 0.77 342.57 379.88 Example 21 Zr _71.7 Co ₇ Fe ₅ Cu _16.3 0.5 ↓ 0.72 339.63 379.66 Example 22 Zr _73.2 Co ₁₁ Cu _15.8 0.5 0.58 356.8 379.4 Example 23 Zr _73.6 Ni ₂ Co ₃ Cu _21.4 0.5 ↓ 0.74 335.35 359.94 Example 24 Zr _73.75 Co _4.8 Cu _21.45 0.5 0.77 351.51 374.51 Example 25 Zr _74.05 Ni ₂ Co _4.8 Cu _19.15 0.5 0.63 331.9 348.54 Example 26 Zr _74.8 Ni ₆ Co _5.4 Cu _13.8 0.5 0.88 341.54 364.89 Example 27 Zr _75.7 Ni ₆ Co _8.6 Cu _9.7 0.5 0.83 335.77 349.06 Example 28 Zr _76.35 Ni ₆ Co _10.75 Cu _6.9 0.5 ↓ 0.74 344.41 398.41 Example 29 Zr _77.1 Ni ₃ Co _15.1 Cu _4.8 0.5 ↓ 0.77 348.51 394.21

Example Furtherance Formability Grain size
( 탆) T _g (° C) T _x (° C) Example 30 Zr ₆₂ Al ₈ Co ₂₆ Cu ₄ 0.5 1.21 425.42 449.97 Example 31 Zr _62.5 Al ₈ Co ₂₃ Ni ₄ Cu _2.5 0.5 0.99 426.53 448.17 Example 32 Zr _69.9 Al ₃ Co ₅ Fe ₃ Cu _19.1 0.5 0.62 360.07 397.84 Example 33 Zr ₇₀ Al ₉ Co ₁₁ Cu ₁₀ One 0.48 376.4 415.75 Example 34 Zr _70.2 Al ₂ Ni ₆ Cu _11.8 One 0.84 354.68 390.67 Example 35 Zr _70.3 Al ₈ Co ₁₀ Cu _11.7 0.5 0.51 372.11 411.21 Example 36 Zr _70.6 Al ₈ Co ₁₁ Cu _10.4 One 0.56 340.95 409.76 Example 37 Zr _70.9 Al ₃ Co ₇ Fe ₂ Cu _17.1 0.5 0.72 357.05 393.4 Example 38 Zr ₇₁ Al ₃ Co ₇ Fe ₃ Cu ₁₆ 0.5 0.69 341.79 392.97 Example 39 Zr _71.8 Al ₃ Co ₅ Fe ₅ Cu _15.2 0.5 0.66 360.93 393.05 Example 40 Zr _71.8 Al ₈ Co _15.2 Cu ₅ 0.5 0.57 382.52 408.6 Example 41 Zr _72.8 Al ₅ Co ₉ Ni ₆ Cu _7.2 0.5 0.52 349.9 393.3 Example 42 Zr _73.6 Al ₅ Co ₁₅ Cu _6.4 0.5 0.52 338.81 392.69 Example 43 Zr _73.7 Al ₃ Co ₅ Fe ₅ Cu _15.3 0.5 0.69 348.96 372.88 Example 44 Zr _73.7 Al ₁₀ Co _8.5 Cu _7.80 0.5 0.51 377.23 391.26 Example 45 Zr _74.3 Al ₄ Co _15.5 Cu _6.2 0.5 0.48 341.65 389.37 Example 46 Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 0.5 1.32 357.75 374.46

Referring to Table 1, the composition of the target for sputtering according to some embodiments of the present invention (Examples 1 to 29) is such that Zr is 58 atom% to 78 atom%; 4 atom% to 26 atom% Cu; At least one selected from Fe, Ni and Co is 4 atom% to 20 atom%. According to the above composition, the composition of the sputtering target according to some embodiments of the present invention (Examples 1 to 29) does not contain aluminum (Al).

Referring to Table 2, the composition of the target for sputtering according to some embodiments of the present invention (Examples 30 to 46) includes Zr of 62 atom% to 76 atom%; Al is less than 10 atomic% (more than 0 atomic%); 2 atom% to 20 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is composed of 6 atom% to 27 atom%.

The amorphous formability means a relative measure indicating how much the alloy of a specific composition can be easily amorphized up to a certain cooling rate. Generally, in order to form an amorphous alloy through casting, a high cooling rate higher than a certain level is required. When the casting method is used with a relatively slow solidification rate (for example, a copper mold casting method), the composition range of amorphous formation is reduced, The rapid solidification method such as melt spinning in which a molten alloy is dropped on a rotating copper roll to solidify it with a ribbon or a wire can achieve a maximized cooling rate of 10 ⁴ K / sec to 10 ⁶ K / sec or more to form amorphous The composition range that can be used is increased. Therefore, the evaluation of the degree of amorphous formability of a particular composition is generally characterized by a relative value depending on the cooling rate of a given rapid cooling process.

Since the amorphous forming ability depends on the alloy composition and the cooling rate, generally the cooling rate is inversely proportional to the casting thickness ([cooling rate] α [casting thickness] ^-2 ), so the critical thickness of the casting material The amorphous forming ability can be relatively quantified. For example, according to the copper mold casting method, the critical casting thickness of the casting material (in case of a stick-shaped casting) capable of obtaining an amorphous structure can be expressed as a diameter. As another example, when the ribbon is formed by melt spinning, it can be expressed as a critical thickness of the ribbon in which amorphous is formed.

In the present invention, an amorphous alloy having an amorphous formability means that an amorphous ribbon is obtained at a casting thickness in the range of 20 μm to 100 μm when casting the molten alloy at a cooling rate in the range of 10 ⁴ K / sec to 10 ⁶ K / sec Means an alloy that can be formed.

Referring to Table 1 and Table 2, the alloy constituting the target for sputtering according to some embodiments of the present invention (Examples 1 to 46) has an amorphous forming ability. The unit of amorphous formability shown in Tables 1 and 2 is mm. For example, the amorphous ability of the alloy having the composition according to Example 3 is less than 0.5 mm, and the amorphous ability of the alloy having the composition according to Example 30 is 0.5 mm.

 Referring to Table 1 and Table 2, the alloy constituting the target for sputtering according to some embodiments of the present invention is characterized in that the grain size of the alloy is 5 탆 or less, for example, in the range of 0.1 탆 to 5 탆, 2.5 < / RTI >

FIG. 2 is a photograph of a Vickers-pressure particle test result of a crystalline alloy having the composition disclosed in Examples of the present invention according to Tables 1 and 2, and FIG. 3 is a graph The results of observing the microstructure of the crystalline alloy having the composition disclosed in US Pat.

Referring to FIGS. 2 and 3, it was confirmed that cracks were not observed in the crack generation test for the crystalline alloy having the composition disclosed in the examples of the present invention according to Tables 1 and 2, , It was confirmed that crystal grains having a grain size of 1 탆 or less were uniformly distributed.

4A and 4B are photographs of a target surface observed after sputtering of a target for sputtering according to some embodiments of the present invention. 4A and 4B are photographs of a sputtering target having the composition of Example 27 of Table 1, and FIG. 4B is a photograph of a sputtering target having a composition of Example 46 of Table 2, (c) is a photograph of the sputtering target having the composition of Example 8 of Table 1 observed.

4A and 4B, after a crystalline alloy target prepared by sintering an amorphous alloy powder by the heat treatment method shown in FIG. 1 is mounted on an actual sputtering apparatus and sputtering is performed by applying a 300 W DC plasma power, a very smooth surface , And it was confirmed that no large change of the alloy structure was observed before and after sputtering. From this, it can be seen that the crystalline alloy target according to the embodiment of the present invention exhibits excellent thermal / mechanical stability that does not show changes in alloy structure even when the temperature is raised during sputtering.

A sputtering thin film formed from an alloy target

The nitride film formed by the sputtering process using the alloy target for sputtering according to the technical idea of the present invention will hereinafter be referred to as a nano-structured film containing nitrogen, a nano-nitride film, or a nano-structured composite film. Further, the amorphous film formed by the sputtering process using the alloy target for sputtering according to the technical idea of the present invention can be referred to as an amorphous alloy film in the following.

When a thin film is formed on a base material by reactive sputtering using the alloy target, the thin film may have a nanostructure composite thin film. For example, when sputtering is performed while introducing a gas containing nitrogen gas (N ₂ ) or nitrogen (N) as a reactive gas into the sputtering chamber, for example, a gas such as NH ₃ , Zr can react with nitrogen to form a Zr nitride. Other elements may be solubilized in the Zr nitride or may be present in the metal phase.

In the present specification and claims, the nanostructure composite thin film has a fine grain size corresponding to a crystal grain size in the range of 5 nm to 30 nm, strictly in the range of 5 nm to 10 nm, and has a structure in which a nitride phase of a metal and at least one metal phase are mixed May be referred to as a thin film. The nitride phase of the metal may include, for example, Zr as a constituent element of the nitride. At this time, the nanostructured composite thin film exhibits a crystal structure of Zr nitride, and other metal elements can be dissolved in Zr nitride in the form of nitride. At this time, Zr nitride includes ZrN or Zr ₂ N. On the other hand, the metal phase may include a metal element having a lower nitride forming ability than the metal element constituting the nitride, for example, Co.

In the nano-structured composite thin film, the nitride phase of the metal has a nanocrystalline structure consisting of crystal grains of several tens to several nanometers in size. On the other hand, the metal phase can be distributed in a trace amount to such a nanocrystalline system. For example, the metal phase is distributed in several atomic units and can exist in a form that does not form a special crystal structure. However, such a metal phase is not distributed intensively in a specific region but is uniformly distributed throughout the thin film.

Meanwhile, when a thin film is formed on a base material by non-reactive sputtering using an alloy target according to embodiments of the present invention, the thin film may be an amorphous alloy film. Here, the non-reactive sputtering means sputtering in which sputtering is performed only with an inert gas, for example, argon, without intentionally introducing a gas reactive with the material constituting the alloy target into the sputtering apparatus. The alloy target according to the embodiments of the present invention has an amorphous ability to form and thus can exhibit an amorphous alloy structure in a process in which a solid phase is formed at a high cooling rate such as sputtering. The amorphous alloy film formed at this time may have a composition approximate to the composition of the alloy target used for sputtering. In the present specification and claims, the amorphous alloy has substantially no specific crystal structure, and the X-ray diffraction pattern does not exhibit a sharp peak sharp at a specific Bragg angle but has a broad peak at a wide angle range May refer to a metal alloy body having an image to be observed.

On the other hand, the present inventors have experimentally confirmed that an amorphous alloy film can be formed even when a small amount of nitrogen is contained in an argon atmosphere in a non-reactive sputtering process (for example, Ar: 45 sccm, N ₂ : 4 sccm). When the amount of nitrogen is small, crystalline ZrN is not produced and nitrogen is judged to be dissolved in the amorphous alloy film. The amorphous film formed by sputtering in an argon atmosphere containing a small amount of nitrogen maintains a color of metallic color and has a property of increasing hardness and resistance compared to a general amorphous film, and thus can be applied to decorative and / or radio wave transmission coatings.

Hereinafter, specific experimental results of the sputtering thin film are provided to help understand the present invention.

 Table 3 shows the results of evaluating the characteristics of the amorphous film formed from the alloy target for sputtering according to the embodiments of the present invention.

Target segment Target alloy composition Sputtering conditions Hardness (GPa) Modulus of elasticity (GPa) Example 27 Zr _75.7 Ni ₆ Co _8.6 Cu _9.7 840 W-300 min, Ar: 50 sccm 5.08 90.70 Example 46 Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 840 W-30 min,
Ar: 50 sccm 7.02 134.9 Example 16 Zr _70.2 Ni ₁ Co ₁₁ Cu _17.8 840 W-30 min,
Ar: 50 sccm 6.15 108.47 Example 8 Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ 840 W-30 min,
Ar: 50 sccm 6.52 110.73

Figures 5 and 6 show an X-ray diffraction pattern for a thin film formed by a sputtering process using a target for sputtering (see Table 3) according to some embodiments of the present invention.

Referring to FIG. 5, the sputtering thin film of the sputtering thin film according to the sputtering conditions shown in Table 3 shows that the -ray diffraction pattern does not show a sharp peak at a specific Bragg angle but a broad peak is observed in a wide angle range Phase is an amorphous thin film.

For example, a crystalline alloy target according to Example 8 (Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ ) was placed in a sputtering apparatus and non-reactive sputtering was performed for 30 minutes by applying 840 W DC plasma power while supplying 50 sccm of argon As a result, an amorphous thin film having a hardness of 6.52 GPa was realized.

Fig. 6 is a result of X-ray diffraction analysis of a thin film formed under various conditions using the sputtering alloy target according to Example 27 of Table 3. Fig. 6 (a) is a result of analyzing a thin film formed by performing a sputtering process only on the target in an atmosphere of argon gas, and FIGS. 6 (b) to 6 (e) The results of analysis of the thin film formed by sputtering while increasing the flow rate of argon gas and nitrogen gas having the flow rate of nitrogen and nitrogen gas.

Referring to FIG. 6A, it can be seen that an amorphous alloy film can be formed in an argon atmosphere in a non-reactive sputtering process. Referring to FIGS. 6B and 6C, in the non-reactive sputtering process, It was confirmed that an amorphous alloy film can be formed even when a small amount of nitrogen is contained in the atmosphere (for example, Ar: 45 sccm, N ₂ : 4 sccm). In the case of a small amount of nitrogen, it is judged that the crystalline is not generated ZrN and nitrogen is dissolved in the amorphous alloy film. The amorphous film formed by sputtering in an argon atmosphere containing a small amount of nitrogen maintains a color of metallic color and has a property of increasing hardness and resistance compared to a general amorphous film, and thus can be applied to decorative and / or radio wave transmission coatings. On the other hand, in (d) and (e) of FIG. 6 in which the nitrogen content is 6 sccm or more, a ZrN phase was observed to confirm that a nitride thin film was formed.

  Element   Wt%   At%    ZrL 69.65  59.96   AlK  00.56  01.63   CoK   16.42   21.88   CuK   13.37   16.53

Table 4 shows the result of energy spectroscopy (EDS) analysis showing the content of the composition in the amorphous thin film realized by the sputtering process using the sputtering target of Example 46 shown in Table 3. [ It can be seen from this that, when using the target according to the embodiment of the present invention, the compositional deviation between the target composition and the thin film composition due to the difference in the sputtering yield of the multi-component is relatively small.

Table 5 shows the results of evaluating the characteristics of the nano-nitride film formed from the alloy targets for sputtering according to the embodiments of the present invention. Although the same sputtering alloy target shown in Table 4 was used, it can be confirmed that a nano-nitride film other than the amorphous film can be formed according to the sputtering conditions.

Target segment Target alloy composition Sputtering conditions Hardness (GPa) Modulus of elasticity (GPa) Example 27 Zr _75.7 Ni ₆ Co _8.6 Cu _9.7 840W-45min,
Ar: N ₂ = 45: 6 25.81 277.61 Example 27 Zr _75.7 Ni ₆ Co _8.6 Cu _9.7 1520 W-60 min,
Ar: N ₂ = 6: 6 31.5 307.4 Example 27 Zr _75.7 Ni ₆ Co _8.6 Cu _9.7 1520 W-60 min,
Ar: N ₂ = 6: 7 35.3 344.8 Example 46 Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 1520 W-45 min,
Ar: N ₂ = 6: 4 23.54 230.54 Example 46 Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 1520 W-45 min,
Ar: N ₂ = 6: 5 28.97 269.21 Example 46 Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 1520 W-45 min,
Ar: N ₂ = 6: 6 33.06 328.36 Example 16 Zr _70.2 Ni ₁ Co ₁₁ Cu _17.8 1520 W-45 min,
Ar: N ₂ = 6: 5 28.28 262.12 Example 8 Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ 2000 W-45 min,
Ar: N ₂ = 6: 9 27.62 318.45 Example 8 Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ 2000 W-45 min, Ar: N ₂ = 6: 7 26.6 288.19 Example 8 Zr ₆₅ Ni ₅ Co ₅ Fe ₅ Cu ₂₀ 3000 W-45 min, Ar: N ₂ = 6: 9 27.56 299.83

7 is an X-ray diffraction pattern of a thin film formed by a sputtering process using a sputtering target (Example 46, Zr _75.1 Al ₄ Co ₁₁ Cu _9.9 ) according to an embodiment of the present invention.

Referring to FIG. 7A, non-reactive sputtering was performed by applying a 1520 W DC plasma power while supplying 50 sccm of argon at a pressure of 5 mtorr. As a result, an amorphous thin film having a hardness of 7.02 GPa and an elastic modulus of 134 GPa was realized.

Referring to FIG. 7 (b), reactive sputtering was performed by applying a 1520 W DC plasma power while supplying argon and nitrogen at a mixing ratio of 6: 4 at a pressure of 0.8 mtorr. As a result, the hardness of 23.54 GPa and the hardness of 230.54 GPa It was confirmed that the thin film having elastic modulus was implemented and that the position of the pick moved in the ZrN (200) direction. Thus, it was confirmed that the amorphous thin film and the nitride thin film were mixed.

Referring to FIG. 7C, reactive sputtering was performed by applying a 1520 W DC plasma power while supplying argon and nitrogen at a mixing ratio of 6: 5 at a pressure of 0.8 mtorr. As a result, the hardness of 28.97 GPa and the hardness of 269.21 GPa A nitride thin film having an elastic modulus was realized.

Referring to FIG. 7D, reactive sputtering was performed by applying a 1520 W DC plasma power while supplying argon and nitrogen at a mixing ratio of 6: 6 at a pressure of 0.8 mtorr. As a result, the hardness of 33.06 GPa and the hardness of 328.36 GPa A nitride thin film having an elastic modulus was realized.

Figures 8 and 9 are the results of the lubrication friction test of nanostructure composite thin films according to some embodiments of the present invention.

FIG. 8 is a graph showing the relationship between the friction coefficient of the coating layer reactively sputtered on the top surface of the tappet of an automobile engine part by applying a 1520 W DC plasma power while supplying argon and nitrogen at a mixing ratio of 6: 6 at a pressure of 0.8 mtorr using the sputtering target of the composition of Example 46 Test results. Friction characteristics were compared using DLC coated parts and uncoated tappets as comparative materials. To confirm the durability of the nitride thin film, a bearing ball having a diameter of 10 mm was used as a counter material and a pressure load of 200 N was tested. 8 (b)) and the uncoated part (FIG. 8 (a)), which is a comparative material after 6 hours, was found to have a steady decrease in the coefficient of friction, Is 0.04 in the case of the nitride thin film (Fig. 8 (c)), as compared with the case where the coefficient of friction is 0.07.

 9 is a graph showing the results of a ring-liner friction test of a nitride thin film of the composition of Example 27 coated on the top surface of a piston ring as a result of a friction test of a reactive sputtered coating layer on a piston ring surface of an automobile engine component using the sputtering target of the composition of Example 27 to be. The nitrided specimen (a), Si-DLC coated specimen (b), CrN coated specimen (c) and Ta-C coated specimen (d) In the case of conventional coated specimens, a friction coefficient of 0.1 or more was observed after 1 hour of friction test, but the coefficient of friction of 0.04 level of nitride thin film was found to be significantly lower than that of conventional coatings.

Referring to FIGS. 8 and 9, the nanostructure composite thin film formed from the sputtering target having the compositions shown in Table 2 and Table 3 exhibited excellent hardness, adhesion, and remarkably excellent low friction characteristics . It is known that when a solid contact occurs due to high load and high pressure, the temperature of the contact portion instantaneously rises to a temperature high enough to cause a reaction between solids or a reaction between a solid and an oil component. In this embodiment, It is believed that this reaction causes easy shear boundary film (easy shear boundary film) with favorable shear deformation and therefore favorable lubrication properties, and that they have a favorable friction characteristic.

The nanostructure composite thin film according to an embodiment of the present invention can be used for manufacturing a low friction characteristic member for improving the friction characteristics of various mechanical parts. For example, it is applied to a tappet, a piston ring, a piston pin, a cam cap, a journal metal bearing, and an injector part as an engine part for a transportation device such as an automobile, thereby reducing frictional and wear in the engine driving process. As another example, the present invention can be applied to gears of a transmission or a power transmission device, or to various kinds of molds, sliding bearings, and folding holes to realize low friction, thereby contributing to improvement of mechanical and chemical properties of the parts.

While the present invention has been described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (13)

Preparing a plurality of amorphous alloys or nanocrystalline alloys containing metal elements having amorphous forming ability;
Shrinking the plurality of amorphous alloys or nanocrystalline alloys by first pressing the amorphous alloy or nanocrystalline alloy at a temperature in the range of the glass transition temperature (Tg) to the crystallization start temperature (Tx) of the amorphous alloy or the nanocrystalline alloy; And
Secondarily shrinking the plurality of amorphous alloys or nanocrystalline alloys by pressurizing the amorphous alloy or the nanocrystalline alloy in a temperature range of 0.7 to 0.9 times the melting temperature (Tm) of the amorphous alloy or nanocrystalline alloy;
/ RTI >
The amorphous alloy or the nanocrystalline alloy contains 58 atom% to 78 atom% of Zr; 4 atom% to 26 atom% Cu; And at least one selected from the group consisting of Fe, Ni and Co is 4 atom% to 20 atom%. delete delete The method according to claim 1,
The first shrinkage; And a second contraction of said second contraction,
Wherein the pressurization is carried out under a pressure in the range of 10 MPa to 50 MPa,
A method for producing a crystalline alloy. The method according to claim 1,
Between the first shrinking step and the second shrinking step,
Heating the plurality of amorphous alloys or nanocrystalline alloys;
≪ / RTI > The method according to claim 1,
Wherein the first shrinking step comprises controlling the porosity between the plurality of amorphous alloys or the nanocrystalline alloy to be 1% or less. The method according to claim 1,
Wherein the second shrinking step comprises controlling the porosity between the plurality of amorphous alloys or the nanocrystalline alloy to 0.1% or less. The method according to claim 1,
Wherein said second shrinking comprises crystallizing a plurality of said amorphous alloys or nanocrystalline alloys such that the mean grain size of said amorphous alloy or grains is in the range of 0.1 탆 to 5 탆. The method according to claim 1,
Wherein the amorphous alloy or the nanocrystalline alloy has at least one shape selected from the group consisting of a foil, a powder, a block, and a rod. 10. A crystalline alloy as embodied by a manufacturing method according to any one of claims 1 to 9,
Zr is 58 atomic% to 78 atomic%; 4 atom% to 26 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is 4 atom% to 20 atom%. delete 10. A sputtering target comprising the crystalline alloy as embodied by the manufacturing method according to any one of claims 1 to 9,
Wherein the crystalline alloy contains Zr in an amount of 58 atom% to 78 atom%; 4 atom% to 26 atom% Cu; At least one selected from the group consisting of Fe, Ni and Co is 4 atom% to 20 atom%. delete

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