Preparation method of high-entropy alloy thin film with adjustable components and crystal phase
By using magnetron sputtering technology to control the composition and crystal phase of high-entropy alloy thin films in a vacuum environment, the problem of difficulty in controlling high-entropy alloy thin films in existing technologies has been solved, and low-cost and efficient preparation has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN UNIV OF TECH
- Filing Date
- 2024-10-21
- Publication Date
- 2026-05-12
AI Technical Summary
The crystal phase structure and composition of existing high-entropy alloy thin films are difficult to control, and the production cost is high, requiring expensive instruments and equipment.
By employing magnetron sputtering technology, metal targets such as FeCoNi, Mo, and Cu are installed at different target sites, and the vacuum level and sputtering gas flow rate are controlled, the composition and crystal phase structure of high-entropy alloy thin films can be adjusted, simplifying the preparation process.
This method enables controllability of the crystal phase structure and composition of high-entropy alloy thin films, reduces production costs, and improves the simplicity of the preparation method.
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Figure CN119843229B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of high-performance alloy materials technology, specifically relating to a method for preparing high-entropy alloy thin films with controllable composition and crystal phase. Background Technology
[0002] With the continuous progress of society and the rapid development of science and technology, the demand for high-performance alloy materials in my country and the world is increasing. Traditional alloys, i.e., single-element alloys, can no longer meet the performance requirements of various industries, such as aerospace, new energy, and national defense. Therefore, the preparation of a high-performance alloy material with multiple excellent properties has become a research hotspot. Against this background, high-entropy alloys have been proposed. Due to their groundbreaking design concept and unique physical, chemical, and mechanical properties, high-entropy alloys have attracted widespread research and attention globally. High-entropy alloys combine the excellent properties of multiple elements, such as good mechanical properties, corrosion resistance, and potential magnetic properties. High-entropy alloys typically contain multiple (5-13) main elements, have a simple crystal phase structure, and tend to form a single solid solution crystal phase, which can produce unusual mechanical properties. By mixing multiple main elements, "chemical disorder" is introduced. Unlike traditional alloys, high-entropy alloys do not have a dominant element or main component, making them a new type of alloy material with unique structural and performance characteristics.
[0003] High-entropy alloys exhibit excellent mechanical properties, corrosion resistance, and high-temperature performance. Due to their superior comprehensive properties, they are applied in extreme environments such as high temperature, high pressure, and corrosive liquids, increasing the service life of workpieces. In recent years, research on high-entropy alloy thin films has achieved many breakthroughs, including the preparation of novel high-entropy alloy thin films, improvements in synthesis methods, and performance optimization. However, the crystal phase structure and composition of existing high-entropy alloy thin films are difficult to control, and they require expensive equipment, resulting in high production costs. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing high-entropy alloy thin films with controllable composition and crystal phase, thereby solving the problems that the crystal phase structure and composition of existing high-entropy alloy thin films are difficult to control, and that they require expensive instruments and equipment and have high production costs.
[0005] To achieve the above objectives, the technical solution adopted in this invention is: a method for preparing high-entropy alloy thin films with controllable composition and crystal phase, specifically implemented according to the following steps:
[0006] Step 1: Cut the Si wafer into square pieces;
[0007] Step 2: Turn on the magnetron sputtering system, install the FeCoNi ternary alloy target with equal atomic ratio at target position 1, the Mo metal target at target position 2, and the Cu metal target at target position 3. Then turn on the cooling water system, place the square sheet in the center of the sample tray and put it into the vacuum chamber, and finally evacuate the vacuum.
[0008] Step 3: Turn on the vacuum indicator, control the rotation speed of the sample stage to 5 r / min, introduce pure Ar gas as sputtering gas, and maintain the vacuum level by controlling the flow rate of Ar gas.
[0009] Step 4: Set the sputtering power and sputtering time, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film.
[0010] As a preferred technical solution of the present invention, in step 1, a Si wafer with a diameter of 100mm is cut into square pieces of 10mm×10mm.
[0011] As a preferred technical solution of the present invention, in step 1, the flat plate is subjected to deionized water cleaning treatment, acetone cleaning treatment and anhydrous ethanol ultrasonic cleaning treatment respectively.
[0012] As a preferred technical solution of the present invention, in step 1, the cooling water temperature in the cooling water system is set to 17.5℃-18.5℃.
[0013] As a preferred technical solution of the present invention, in step 2, the vacuum is evacuated to 2×10⁻⁶. -2 Pa -5×10 -2 Pa.
[0014] As a preferred embodiment of the present invention, in step 2, the vacuum level is maintained at 5×10⁻⁶. -2 Pa.
[0015] As a preferred technical solution of the present invention, in step 2, a Mo metal target is installed at target position 2 and a Cr metal target is installed at target position 3.
[0016] As a preferred technical solution of the present invention, in step 2, a Cr metal target is installed at target position 2 and a Cu metal target is installed at target position 3.
[0017] The beneficial effects of the present invention are: the method for preparing high-entropy alloy thin films with controllable composition and crystal phase of the present invention can control the crystal phase structure and composition of high-entropy alloy thin films during the preparation process, the preparation method is simple and greatly reduces the production cost. Attached Figure Description
[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:
[0019] Figure 1 This is a diagram showing the surface morphology of the FeCoNiCuMo high-entropy alloy thin film prepared in Example 1 and the elemental distribution of each component in EDS.
[0020] Figure 2 These are X-ray diffraction (XRD) patterns of FeCoNiCuMo high-entropy alloy thin films prepared in Example 1 under different Mo target sputtering powers (40-70W);
[0021] Figure 3 The microhardness and elastic modulus of FeCoNiCuMo high-entropy alloy films prepared in Example 1 under different Mo target sputtering powers (40-70W);
[0022] Figure 4 This is a diagram showing the surface morphology of the FeCoNiCrMo high-entropy alloy thin film prepared in Example 2 and the elemental distribution of each component in EDS.
[0023] Figure 5 These are XRD patterns of FeCoNiCrMo high-entropy alloy thin films prepared in Example 2 under different Mo target sputtering powers (30-50W);
[0024] Figure 6 The microhardness and elastic modulus of FeCoNiCrMo high-entropy alloy films prepared in Example 2 under different Mo target sputtering powers (30-50W);
[0025] Figure 7 This is a diagram showing the surface morphology of the FeCoNiCuCr high-entropy alloy thin film prepared in Example 3 and the elemental distribution of each component in EDS.
[0026] Figure 8 These are X-ray diffraction (XRD) patterns of FeCoNiCuCr high-entropy alloy thin films prepared in Example 3 under different Cr target sputtering powers (40-70W);
[0027] Figure 9 The microhardness and elastic modulus of FeCoNiCuCr high-entropy alloy films prepared in Example 3 under different Cr target sputtering powers (40-70W) are shown. Detailed Implementation
[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] The method for preparing high-entropy alloy thin films with controllable composition and crystal phase of the present invention is specifically implemented according to the following steps:
[0030] Step 1: Cut the 100mm diameter Si wafer into 10mm×10mm square pieces. Then, perform deionized water cleaning, acetone cleaning, and ultrasonic cleaning with anhydrous ethanol on the square pieces to remove residual debris and large dust particles, as well as moisture, residual acetone, and other possible water-soluble dirt from the surface of the square pieces.
[0031] Step 2: Turn on the magnetron sputtering system. Install the FeCoNi ternary alloy target at target position 1, the Mo metal target at target position 2, and the Cu metal target at target position 3. Then turn on the cooling water system and set the cooling water temperature to 17.5℃-18.5℃. Next, place the sample plate in the center of the sample tray and put it into the vacuum chamber. Finally, evacuate to 2×10⁻⁶. -2 Pa -5×10 -2 Pa;
[0032] Step 3: Turn on the vacuum indicator, control the stage rotation speed to 5 r / min, introduce pure Ar gas as the sputtering gas, and maintain the vacuum level at 5 × 10⁻⁶ by controlling the Ar gas flow rate. -2 Pa;
[0033] Step 4: Set the sputtering power and sputtering time, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film.
[0034] Example 1
[0035] The present invention provides a method for preparing high-entropy alloy thin films with tunable composition and crystal phase, which is specifically implemented according to the following steps:
[0036] Step 1: Cut the 100mm diameter Si wafer into 10mm×10mm square pieces. Clean the square pieces with deionized water, acetone, and anhydrous ethanol for 10 minutes to remove residual debris and large dust particles, as well as moisture, residual acetone, and other possible water-soluble dirt from the surface of the square pieces.
[0037] Step 2: Turn on the magnetron sputtering system. Install the FeCoNi ternary alloy target at target position 1, the Mo metal target at target position 2, and the Cu metal target at target position 3. Then turn on the cooling water system and set the cooling water temperature to 17.5℃. Next, place the sample plate in the center of the sample tray and put it into the vacuum chamber. Finally, evacuate to 2×10⁻⁶. -2 Pa;
[0038] Step 3: Turn on the vacuum indicator, control the stage rotation speed to 5 r / min, introduce pure Ar gas as the sputtering gas, and maintain the vacuum level at 5 × 10⁻⁶ by controlling the Ar gas flow rate. -2 Pa;
[0039] Step 4: Set the sputtering power of target position 2 to 70W and target position 3 to 30W, the sputtering time to 1800s, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film.
[0040] The surface morphology and elemental composition of the FeCoNiCuMo high-entropy alloy film were analyzed using scanning electron microscopy. The SEM surface morphology and EDS elemental distribution of the film were obtained under the following conditions: Mo target power of 70W and Cu target power of 30W. Figure 1 As shown in Figure 1, the surface morphology, EDS, and elemental distribution of the FeCoNiCuMo high-entropy alloy film were obtained when the Mo target sputtering power was 70W: (a) region shows the surface morphology, (b) region shows the EDS layering, (c) region shows Fe, (d) region shows Co, (e) region shows Ni, (f) region shows Cu, and (g) region shows Mo. The elements are randomly and uniformly distributed, as shown in Table 1. The prepared film conforms to the definition of a high-entropy alloy.
[0041] Table 1. Atomic percentage of elemental composition (at%) of FeCoNiCuMo high-entropy alloy thin films.
[0042]
[0043] Figure 2 X-ray diffraction (XRD) patterns of FeCoNiCuMo high-entropy alloy films prepared under different Mo target sputtering powers (40-70 W) are shown. The XRD patterns reveal that, excluding the diffraction peaks on the Si substrate, the alloy exhibits only one diffraction peak, indicating that the prepared FeCoNiCuMo high-entropy alloy film is not a complex polycrystalline structure but a single-crystal FCC structure (diffraction peak at 44°). The FCC phase diffraction peak tends towards the (111) crystal plane orientation. With increasing Mo target power, the full width at half maximum (FWHM) of the FCC (111) crystal plane decreases, while the diffraction peak intensity increases, indicating that the film maintains good crystallinity on the (111) crystal plane even with increasing Mo content. According to the Scherrer equation, the grain sizes are 8.9 nm, 9.2 nm, and 10.8 nm at Mo target sputtering powers of 40, 60 W, and 70 W, respectively. The reason is that when the Mo target power increases in the range of 40W to 70W, the speed and energy of particles reaching the substrate surface are still ideal, which promotes the growth and crystallization of the film on the FCC(111) crystal plane. Therefore, the FeCoNiCuMo high-entropy alloy film has a single-phase FCC structure.
[0044] Figure 3 The microhardness and elastic modulus of FeCoNiCuMo high-entropy alloy films prepared under different Mo target sputtering powers (40-70W) were determined. Figure 3 The data shows that as the Mo target power increases, the microhardness of the film increases, but the elastic modulus decreases and then increases again. At a Mo target power of 70 W, the microhardness and elastic modulus of the prepared film both reach their maximum values of 7.98 GPa and 203.47 GPa, respectively. This indicates that the addition of a certain amount of Mo is beneficial for improving the hardness and elastic modulus of the film. Mo has the largest atomic radius among the alloy constituent elements; its addition can produce a lattice distortion effect in the alloy solid solution, hindering dislocation movement and thus increasing the alloy's hardness.
[0045] Example 2
[0046] The present invention provides a method for preparing high-entropy alloy thin films with tunable composition and crystal phase, which is specifically implemented according to the following steps:
[0047] Step 1: Cut the 100mm diameter Si wafer into 10mm×10mm square pieces. Then, perform deionized water cleaning, acetone cleaning, and ultrasonic cleaning with anhydrous ethanol on the square pieces to remove residual debris and large dust particles, as well as moisture, residual acetone, and other possible water-soluble dirt from the surface of the square pieces.
[0048] Step 2: Turn on the magnetron sputtering system. Install the FeCoNi ternary alloy target at target position 1, the Mo metal target at target position 2, and the Cr metal target at target position 3. Then turn on the cooling water system and set the cooling water temperature to 18°C. Next, place the sample plate in the center of the sample tray and put it into the vacuum chamber. Finally, evacuate to 3 × 10⁻⁶. -2 Pa;
[0049] Step 3: Turn on the vacuum indicator, control the stage rotation speed to 5 r / min, introduce pure Ar gas as the sputtering gas, and maintain the vacuum level at 5 × 10⁻⁶ by controlling the Ar gas flow rate. -2 Pa;
[0050] Step 4: Set the sputtering power of target position 2 to 50W and target position 3 to 60W, the sputtering time to 1800s, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film.
[0051] SEM surface morphology images of the FeCoNiCrMo high-entropy alloy film are shown below. Figure 4As shown in Table 2, the elements are randomly and uniformly distributed, and the prepared film conforms to the definition of a high-entropy alloy. At a Mo target power of 50 W, the surface of the high-entropy alloy film is covered with fine and uniformly distributed particles, and no significant particle aggregates or clumps were observed. The surface is very smooth and has very few defects, which is consistent with the typical characteristics of amorphous films.
[0052] Table 2. Atomic percentage of elemental composition (at%) of FeCoNiCrMo high-entropy alloy thin films.
[0053]
[0054] Figure 4. Surface morphology, EDS and elemental distribution of FeCoNiCrMo high-entropy alloy film when the sputtering power of the Mo target is 50W: (a) area is surface morphology, (b) area is EDS layering diagram, (c) area is Fe, (d) area is Co, (e) area is Ni, (f) area is Cr, and (g) area is Mo.
[0055] Figure 5 X-ray diffraction (XRD) patterns of FeCoNiCrMo high-entropy alloy thin films prepared under different Mo target sputtering powers (30-50 W) are shown. The XRD patterns reveal three main diffraction peaks in the FeCoNiCrMo high-entropy alloy, corresponding to Cr-rich BCC, FCC, and FCC structures (diffraction peaks at 40°, 43°, and 75°, respectively). The BCC crystal phase tends towards the (110) orientation. The diffraction peak becomes flat at 50 W, indicating poor crystallinity and amorphous state in the film at this sputtering power.
[0056] The formation of amorphous structures in high-entropy alloys is the result of the combined effects of high-entropy, hysteresis diffusion, and lattice distortion. The specific reasons are as follows: (1) The structural characteristics of high-entropy alloys indicate that as the number of elements in the system increases, the mixing entropy of the system also increases, leading to a significant decrease in the Gibbs free energy. During solidification, the system tends to form simple solid solutions, often accompanied by the formation of nanostructures or amorphous phases. (2) In multi-component systems, differences in atomic size disrupt the periodicity of atomic arrangement, resulting in significant lattice distortion. Lattice distortion reduces the crystallization ability of crystals, hinders lattice growth, and thus promotes the formation of amorphous structures. (3) A fast atomic packing rate and slow diffusion are ideal conditions for the formation of amorphous structures. Due to the large number of elements and significant differences in atomic size in high-entropy alloys, the packing density of the system is high, making interatomic diffusion complex and difficult. Furthermore, magnetron sputtering technology has a very fast cooling rate (>10⁴ K / s) and atomic deposition rate, which means that when atoms first arrive at the Si substrate, there is insufficient time for atomic nucleation in the alloy, resulting in a low diffusion rate. Therefore, more energy is required to complete the crystal phase transformation process, which is slow. This slow crystal phase transformation process inhibits the nucleation and growth of crystalline phases, thus meeting the conditions for the formation of amorphous structures.
[0057] Figure 5. X-ray diffraction (XRD) patterns of FeCoNiCrMo high-entropy alloy thin films prepared under different Mo target sputtering powers (30-50 W).
[0058] Figure 6 The microhardness and elastic modulus of FeCoNiCrMo high-entropy alloy films prepared under different Mo target sputtering powers (30-50W) were determined. Figure 6 The data shows that as the Mo target power increases, the microhardness of the film increases, but the elastic modulus initially increases and then decreases. The microhardness of the prepared film reaches its maximum at a Mo target power of 50 W, and the elastic modulus reaches its maximum at a Mo target power of 40 W, at 10.094 GPa and 203.467 GPa, respectively. In FeCoNiCrMo high-entropy alloy films, the phenomenon of the elastic modulus initially increasing and then decreasing with Mo content is because the addition of Mo may lead to the formation of an ordered BCC structure in the alloy, which usually increases the elastic modulus. However, excessive Mo causes the alloy to transform from an ordered structure to a disordered structure (amorphous structure), which may decrease the elastic modulus.
[0059] Figure 6 Microhardness and elastic modulus of FeCoNiCrMo-based high-entropy alloy thin films prepared under different Mo target sputtering powers (30-50 W). (Unit: GPa)
[0060] Example 3
[0061] The present invention provides a method for preparing high-entropy alloy thin films with tunable composition and crystal phase, which is specifically implemented according to the following steps:
[0062] Step 1: Cut the 100mm diameter Si wafer into 10mm×10mm square pieces. Then, perform deionized water cleaning, acetone cleaning, and ultrasonic cleaning with anhydrous ethanol on the square pieces to remove residual debris and large dust particles, as well as moisture, residual acetone, and other possible water-soluble dirt from the surface of the square pieces.
[0063] Step 2: Turn on the magnetron sputtering system. Install the FeCoNi ternary alloy target at target position 1, the Cr metal target at target position 2, and the Cu metal target at target position 3. Then turn on the cooling water system and set the cooling water temperature to 18.5℃. Next, place the sample plate in the center of the sample tray and put it into the vacuum chamber. Finally, evacuate to 5×10⁻⁶. -2 Pa;
[0064] Step 3: Turn on the vacuum indicator, control the stage rotation speed to 5 r / min, introduce pure Ar gas as the sputtering gas, and maintain the vacuum level at 5 × 10⁻⁶ by controlling the Ar gas flow rate. -2 Pa;
[0065] Step 4: Set the sputtering power of target position 2 to 70W and target position 3 to 30W, the sputtering time to 1800s, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film.
[0066] SEM surface morphology images of the FeCoNiCuCr high-entropy alloy film are shown below. Figure 7 As shown in Table 3, the elements are randomly and uniformly distributed, and the prepared film conforms to the definition of a high-entropy alloy. From the surface morphology images, the film surface is composed of nanospheres of different shapes and sizes, each particle containing a fine island-like structure. The particle size on the film surface is small and unevenly distributed. This is attributed to the fact that when the sputtering power of the Cr target is low, the particles sputtered from the target have low energy, a slow deposition rate, and a low probability of reaching the substrate, resulting in limited diffusion between particles. However, the deposition of high-energy particles also increases the substrate temperature, promoting the crystallization process of the film, leading to poor film formation ability and an uneven surface, although the grains are continuous. With increased sputtering power, the particle size decreases to some extent, the film adheres well to the substrate, and no cracking or peeling is observed.
[0067] Table 3. Atomic percentage of elements (at%) in FeCoNiCuCr based high-entropy alloy films
[0068]
[0069] Figure 7. Surface morphology, EDS and elemental distribution of FeCoNiCuMo high-entropy alloy film when the sputtering power of the Cr target is 70W: (a) area is surface morphology, (b) area is EDS layering diagram, (c) area is Fe, (d) area is Co, (e) area is Ni, (f) area is Cu, and (g) area is Cr.
[0070] like Figure 8 The XRD patterns of FeCoNiCuCr high-entropy alloy films prepared under different Cr target sputtering powers (40-70W) are shown. The XRD patterns reveal four main diffraction peaks in the FeCoNiCuCr high-entropy alloy, corresponding to the Cr-rich BCC, FCC, FCC, and FCC structures (diffraction peaks at 41°, 44°, 50°, and 75°). It was observed that the sin²θ ratios at diffraction angles 2θ of 44°, 50°, and 75° are 3:4:8, indicating an FCC (face-centered cubic) crystal structure. Under different Cr target sputtering powers, the diffraction peak intensity of the (111) crystal plane is stronger than that of other crystal planes, indicating more significant crystal growth on the (111) plane. Therefore, the FeCoNiCuCr high-entropy alloy film is an FCC+BCC dual-phase structure. When the sputtering power of the Cr target is 40W, 60W, and 70W, the grain size is 14.2nm, 13.5nm, and 13.8nm, respectively.
[0071] Figure 9 Microhardness and elastic modulus of FeCoNiCuCr high-entropy alloy films prepared under different Cr target sputtering powers (40-70W). With increasing Cr target power, the microhardness of the film first decreases and then increases, while the elastic modulus decreases, showing a significant drop when the Cr target sputtering power increases from 60W to 70W. Increased Cr content leads to the formation of a Cr-rich BCC crystalline phase structure in the alloy, resulting in crystalline phase precipitation and a decrease in both microhardness and elastic modulus. However, the BCC crystalline phase structure is beneficial for increasing film hardness; therefore, the hardness also increases with increasing Cr content. Cr affects the grain size of the alloy; grain refinement helps improve microhardness and elastic modulus, but excessive Cr addition leads to grain growth, which reduces both microhardness and elastic modulus. Therefore, the increase in Cr content should be moderate to improve the mechanical properties of FeCoNiCrCu high-entropy alloys.
[0072] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.
Claims
1. A method for preparing high-entropy alloy thin films with controllable composition and crystal phase, characterized in that, The specific steps are as follows: Step 1: Cut the Si wafer into square pieces; Step 2: Turn on the magnetron sputtering system, install the FeCoNi ternary alloy target with equal atomic ratio at target position 1, the Mo metal target at target position 2, and the Cu metal target at target position 3. Then turn on the cooling water system, place the square sheet in the center of the sample tray and put it into the vacuum chamber, and finally evacuate the vacuum. Step 3: Turn on the vacuum indicator, control the rotation speed of the sample stage to 5 r / min, introduce pure Ar gas as sputtering gas, and maintain the vacuum level by controlling the flow rate of Ar gas. Step 4: Set the sputtering power and sputtering time, open the target baffle, and start sputtering to obtain a high-entropy alloy thin film; In step 1, a 100mm diameter Si wafer is cut into 10mm×10mm square pieces; the square pieces are then subjected to deionized water cleaning, acetone cleaning, and ultrasonic cleaning with anhydrous ethanol. In step 2, the cooling water temperature in the cooling water system is set to 17.5℃-18.5℃, and a vacuum of 2×10⁻⁶ is applied. -2 Pa-5×10 -2 Pa; In step 3, the vacuum level is maintained at 5 × 10⁻⁶. -2 Pa.
2. The method for preparing high-entropy alloy thin films with controllable composition and crystal phase according to claim 1, characterized in that, In step 2, a Mo metal target is installed at target position 2, and a Cr metal target is installed at target position 3.
3. The method for preparing high-entropy alloy thin films with tunable composition and crystal phase according to claim 1, characterized in that, In step 2, a Cr metal target is installed at target position 2, and a Cu metal target is installed at target position 3.