A polycrystalline composite Mg-Ni-Ti alloy thin film and a preparation method and application thereof
The method for preparing polycrystalline composite Mg-Ni-Ti alloy thin films solves the problem of limited modification methods for magnesium-based hydrogen storage materials, achieving high efficiency in hydrogen storage performance and good reproducibility, while also providing a simple preparation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2024-03-11
- Publication Date
- 2026-05-29
Smart Images
Figure CN118086849B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hydrogen storage materials technology, and in particular to a polycrystalline composite Mg-Ni-Ti alloy thin film, its preparation method, and its application. Background Technology
[0002] Magnesium-based solid-state hydrogen storage materials possess advantages such as light weight, large hydrogen storage capacity, and low cost; however, their thermodynamic stability and slow kinetics limit their applications. To address these shortcomings, researchers have employed various methods to modify magnesium-based hydrogen storage materials. Currently used modification methods include alloying, nano-sizing, and catalyst addition; however, these methods are relatively limited in scope, resulting in limited modification effects.
[0003] Therefore, it is very important to study a more comprehensive modification method for Mg-based hydrogen storage materials to obtain better hydrogen storage performance. Summary of the Invention
[0004] The purpose of this invention is to provide a polycrystalline composite Mg-Ni-Ti alloy thin film, its preparation method and application, in order to solve the problems of poor repeatability, single modification method and poor modification effect of alloy thin films in the prior art.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0006] This invention provides a polycrystalline composite Mg-Ni-Ti alloy thin film, wherein, by atomic percentage, Mg is 68-78%; Ni is 12-17%; and the balance is Ti.
[0007] Furthermore, the polycrystalline composite Mg-Ni-Ti alloy film contains three phases: Mg2Ni, Ti, and Mg.
[0008] Furthermore, a protective layer is deposited on the surface of the polycrystalline composite Mg-Ni-Ti alloy thin film;
[0009] The protective layer is a Pd layer with a thickness of 8–10 nm.
[0010] This invention provides a method for preparing polycrystalline composite Mg-Ni-Ti alloy thin films, comprising the following steps:
[0011] (1) Install Mg target, NiTi target, Pd target and substrate in ultra-high vacuum magnetron sputtering system respectively, and pre-sputter Mg target, NiTi target and Pd target respectively in working gas atmosphere;
[0012] (2) Mg target and NiTi target are co-sputtered on the substrate by magnetron sputtering to obtain polycrystalline composite Mg-Ni-Ti alloy thin film.
[0013] Furthermore, a protective layer is formed by sputtering a Pd target onto the surface of a polycrystalline composite Mg-Ni-Ti alloy thin film.
[0014] Furthermore, in step (1), the substrate is single-crystal silicon or aluminum foil; the vacuum level of the ultra-high vacuum magnetron sputtering system is ≤1.0×10⁻⁶. -3 Pa;
[0015] The working gas is argon, with a flow rate of 22–26 sccm and a pressure of 1.8–2.2 Pa.
[0016] Furthermore, in step (1), the power of pre-sputtering of Mg target is 50-70W, the power of pre-sputtering of NiTi target is 50-70W, and the power of pre-sputtering of Pd target is 50W.
[0017] The Mg and Pd targets were pre-sputtered using DC magnetron sputtering, while the NiTi target was pre-sputtered using radio frequency magnetron sputtering.
[0018] Furthermore, in step (2), the magnetron sputtering co-sputtering time is 30-60 min; the magnetron sputtering co-sputtering power of Mg target is 50-70 W, and the magnetron sputtering co-sputtering power of NiTi target is 50-70 W.
[0019] Furthermore, the sputtering time of the Pd target is 60s; the sputtering power of the Pd target is 50W.
[0020] This invention also provides an application of polycrystalline composite Mg-Ni-Ti alloy thin films in hydrogen storage.
[0021] The beneficial effects of this invention are:
[0022] (1) By giving full play to the synergistic catalytic effect of Mg2Ni and Ti, the present invention can achieve synergistic modification of alloying, catalysis and nano-sizing.
[0023] (2) The preparation method of the present invention is simple, has good repeatability, and uses inexpensive raw materials.
[0024] (3) The preparation method of the present invention can achieve atomic-scale structural control by adjusting the sputtering power of the target material.
[0025] (4) The Mg-Ni-Ti alloy thin film prepared by the present invention has excellent hydrogen storage performance. It absorbs 3.94 wt.% hydrogen in two minutes at 348 K and 5 bar hydrogen pressure, and desorbs 4.072 wt.% hydrogen in 10 minutes at 498 K. The dehydrogenation activation energy is only 55.23 kJ / mol H2. Its hydrogen storage performance is far superior to that of Mg-Ti co-sputtered alloy thin film, Mg-Ni co-sputtered alloy thin film and traditional hydrogen storage materials. Attached Figure Description
[0026] Figure 1 This is a layout diagram of the Mg target, NiTi target, Pd target and substrate installed in the ultra-high vacuum magnetron sputtering system in Embodiment 1 of the present invention.
[0027] Figure 2 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 SEM images of the surface and cross-section of the alloy thin film before and after hydrogen absorption / desorption.
[0028] Figure 3 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 XRD patterns of alloy thin films before and after hydrogen absorption / dehydrogenation.
[0029] Figure 4 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Dehydrogenation kinetics curves of alloy thin films at different temperatures.
[0030] Figure 5 The polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 SEM images of the surface and cross-section of the alloy thin film before and after hydrogen absorption / desorption.
[0031] Figure 6 The polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 XRD patterns of alloy thin films before and after hydrogen absorption / dehydrogenation.
[0032] Figure 7 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film and polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15Hydrogen absorption kinetics curve of alloy thin film at 348K and 5 bar H2.
[0033] Figure 8 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film and polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 Dehydrogenation kinetics of the alloy film at 473 K and 0.015 bar H2.
[0034] Figure 9 The polycrystalline composite Mg obtained in Comparative Example 1 0.78 Ni 0.22 Dehydrogenation kinetics curves of alloy thin films at different temperatures.
[0035] Figure 10 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin films and polycrystalline composite Mg prepared in Comparative Example 1 0.78 Ni 0.22 Fitting graph of dehydrogenation activation energy of alloy thin film.
[0036] Figure 11 For the polycrystalline composite Mg obtained in Comparative Example 2 0.78 Ti 0.22 Dehydrogenation kinetics curves of alloy thin films at different temperatures.
[0037] Figure 12 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film, polycrystalline composite Mg obtained in Comparative Example 1 0.78 Ni 0.22 Alloy thin film and polycrystalline composite Mg obtained in Comparative Example 2 0.78 Ti 0.22 Dehydrogenation kinetics of the alloy film at 498 K and 0.05 bar H2. Detailed Implementation
[0038] This invention provides a polycrystalline composite Mg-Ni-Ti alloy thin film, wherein, by atomic percentage, Mg is 68-78%, Ni is 12-17%, and the balance is Ti.
[0039] In this invention, the polycrystalline composite Mg-Ni-Ti alloy film contains three phases: Mg2Ni, Ti, and Mg.
[0040] In this invention, a protective layer is deposited on the surface of the polycrystalline composite Mg-Ni-Ti alloy thin film;
[0041] The protective layer is a Pd layer with a thickness of 8–10 nm.
[0042] This invention provides a method for preparing polycrystalline composite Mg-Ni-Ti alloy thin films, comprising the following steps:
[0043] (1) Install Mg target, NiTi target, Pd target and substrate in ultra-high vacuum magnetron sputtering system respectively, and pre-sputter Mg target, NiTi target and Pd target respectively in working gas atmosphere;
[0044] (2) Mg target and NiTi target are co-sputtered on the substrate by magnetron sputtering to obtain polycrystalline composite Mg-Ni-Ti alloy thin film.
[0045] In this invention, a Pd target is sputtered onto the surface of a polycrystalline composite Mg-Ni-Ti alloy thin film to form a protective layer.
[0046] In this invention, the substrate is mounted on a rotating substrate located above the sputtering target in an ultra-high vacuum magnetron sputtering system. Before mounting the substrate, a pretreatment is performed. The pretreatment method is as follows: the substrate is ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence, and then the substrate is placed in a vacuum drying oven to dry for later use.
[0047] In this invention, in step (1), the substrate is monocrystalline silicon or aluminum foil, preferably monocrystalline silicon; the vacuum degree of the ultra-high vacuum magnetron sputtering system is ≤1.0×10⁻⁶. -3 Pa, preferably ≤0.8×10 -3 Pa, more preferably ≤0.6×10 -3 Pa.
[0048] In this invention, the working gas is argon with a purity of 99.95%; the flow rate of the working gas is 22-26 sccm, preferably 23-25 sccm; and the pressure of the working gas is 1.8-2.2 Pa, preferably 1.9-2.1 Pa, and more preferably 2 Pa.
[0049] In this invention, in step (1), the power of pre-sputtering of Mg target is 50-70W, the power of pre-sputtering of NiTi target is 50-70W, the power of pre-sputtering of Pd target is 50W, and the Mg target and Pd target are pre-sputtered by DC magnetron sputtering, while the NiTi target is pre-sputtered by radio frequency magnetron sputtering.
[0050] In this invention, the purpose of pre-sputtering Mg, NiTi and Pd targets is to remove contaminants from the target surface.
[0051] In this invention, the purity of the Mg target, NiTi target and Pd target is 99.99%.
[0052] In this invention, in step (2), the magnetron sputtering co-sputtering time is 30-60 min, preferably, and more preferably; the magnetron sputtering co-sputtering power of Mg target is 50-70 W; and the magnetron sputtering co-sputtering power of NiTi target is 50-70 W.
[0053] In this invention, the sputtering time of the Pd target is 60s, and the sputtering power of the Pd target is 50W.
[0054] In this invention, the power of magnetron sputtering co-sputtering of the target material is adjusted in order to obtain polycrystalline composite Mg-Ni-Ti alloy thin films with different compositions.
[0055] This invention also provides an application of polycrystalline composite Mg-Ni-Ti alloy thin films in hydrogen storage.
[0056] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0057] Example 1
[0058] The single-crystal silicon substrate was sequentially sonicated in acetone, anhydrous ethanol, and deionized water for 15 min each. The substrate was then dried in a vacuum drying oven at 50°C to obtain a pretreated substrate. This pretreated substrate was fixed on a rotating substrate located above the sputtering target. Mg, NiTi, and Pd targets with purities of 99.99% were respectively mounted on the sputtering target. The magnetron sputtering system was evacuated to a vacuum level of 1 × 10⁻⁶ using a mechanical pump and a molecular pump. -3 Argon gas with a purity of 99.95% was introduced at a flow rate of 25 sccm and a pressure of 2 Pa. After the gas pressure in the sputtering chamber stabilized, Mg, NiTi, and Pd targets were pre-sputtered to remove contaminants from the target surface. The pre-sputtering power for Mg target was 70 W, for NiTi target it was 60 W, and for Pd target it was 50 W.
[0059] Open the baffles of the Mg target, NiTi target and substrate, and deposit the Mg target and NiTi target on the substrate by magnetron sputtering co-sputtering. The power of the Mg target is 70W and the power of the NiTi target is 60W. Magnetron sputtering co-sputtering is performed for 45 minutes to obtain a polycrystalline composite Mg-Ni-Ti alloy thin film.
[0060] With the Mg and NiTi targets turned off and the Pd target turned on, the sputtering power was 50W for 60 seconds, resulting in a 9nm protective layer on the surface of the polycrystalline composite Mg-Ni-Ti alloy film, thus obtaining the polycrystalline composite Mg 0.78 Ni 0.12 Ti 0.10 alloy film.
[0061] Polycrystalline composite Mg prepared in Example 1 0.78 Ni 0.12 Ti 0.10 The total thickness of the alloy film is approximately 592 nm, and the atomic ratio of Mg:Ni:Ti is 78:12:10.
[0062] Figure 1 This is a layout diagram of the Mg target, NiTi target, Pd target, and substrate mounted in the ultra-high vacuum magnetron sputtering system in Example 1 of the present invention. The Mg prepared in Example 1... 0.78 Ni 0.12 Ti 0.10 The alloy thin film underwent hydrogen absorption / desorption testing, and the results are as follows: Figures 2-4 As shown. Figure 2 Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 SEM images of the surface and cross-section of the alloy thin film before and after hydrogen absorption / desorption. Figure 3 Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 XRD patterns of alloy thin films before and after hydrogen absorption / dehydrogenation. Figure 4 Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Dehydrogenation kinetics curves of alloy thin films at different temperatures. Figures 2-4 As can be seen, in Example 1, all Ni reacts with Mg to form Mg2Ni. In the subsequent hydrogen absorption process, both Mg and Mg2Ni participate in hydrogen absorption, generating MgH2 and Mg2NiH4 respectively, while Ti always exists in the thin film in the form of an element.
[0063] Example 2
[0064] The single-crystal silicon substrate was sequentially sonicated in acetone, anhydrous ethanol, and deionized water for 15 min each. The substrate was then dried in a vacuum drying oven at 50°C to obtain a pretreated substrate. This pretreated substrate was fixed on a rotating substrate located above the sputtering target. Mg, NiTi, and Pd targets with purities of 99.99% were respectively mounted on the sputtering target. The magnetron sputtering system was evacuated to a vacuum level of 1 × 10⁻⁶ using a mechanical pump and a molecular pump. -3Argon gas with a purity of 99.95% was introduced at a flow rate of 25 sccm and a pressure of 2 Pa. After the gas pressure in the sputtering chamber stabilized, Mg, NiTi, and Pd targets were pre-sputtered to remove contaminants from the target surface. The pre-sputtering power for Mg target was 50 W, for NiTi target it was 60 W, and for Pd target it was 50 W.
[0065] Open the baffles of the Mg target, NiTi target and substrate, and deposit the Mg target and NiTi target on the substrate by magnetron sputtering co-sputtering. The power of the Mg target is 50W and the power of the NiTi target is 60W. Magnetron sputtering co-sputtering is performed for 60 minutes to obtain a polycrystalline composite Mg-Ni-Ti alloy thin film.
[0066] With the Mg and NiTi targets turned off and the Pd target turned on, the sputtering power was 50W for 60 seconds, resulting in a 9nm protective layer on the surface of the polycrystalline composite Mg-Ni-Ti alloy film, thus obtaining the polycrystalline composite Mg 0.68 Ni 0.17 Ti 0.15 alloy film.
[0067] Polycrystalline composite Mg prepared in Example 2 0.68 Ni 0.17 Ti 0.15 The total thickness of the alloy film is approximately 581 nm, and the atomic ratio of Mg:Ni:Ti is 68:17:15.
[0068] Figure 5 The polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 SEM images of the surface and cross-section of the alloy thin film before and after hydrogen absorption / desorption. Figure 6 The polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 XRD patterns of the alloy thin film before and after hydrogen adsorption / desorption. Figures 5-6 It can be seen that with the increase of Ni and Ti content, the morphology of the film did not change significantly, and in the deposited film, Ni still completely forms Mg2Ni with Mg, while Ti still exists in the film in the form of elemental form.
[0069] Figure 7 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film and polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 Hydrogen absorption kinetics curve of alloy thin film at 348K and 5 bar H2. Figure 8 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film and polycrystalline composite Mg obtained in Example 2 0.68 Ni 0.17 Ti 0.15 Dehydrogenation kinetics of the alloy film at 473 K and 0.015 bar H2. Figure 7 and Figure 8 Example 1 exhibited rapid hydrogen absorption kinetics, with 3.94 wt.% hydrogen absorption within 2 minutes at 348 K and 5 bar H2, and 3.58 wt.% hydrogen dehydrogenation within 30 minutes at 473 K and 0.015 bar H2. Although Example 2 showed a smaller hydrogen absorption capacity compared to Example 1, it exhibited even faster hydrogen absorption kinetics, with 3.46 wt.% hydrogen absorption within 30 seconds at 348 K and 5 bar H2, and 3.38 wt.% hydrogen dehydrogenation within 15 minutes at 473 K and 0.015 bar H2. With increasing Ni and Ti content, the hydrogen storage capacity of the Mg-Ni-Ti alloy film decreased, but the hydrogen storage kinetics improved.
[0070] Comparative Example 1
[0071] The single-crystal silicon substrate was sequentially sonicated in acetone, anhydrous ethanol, and deionized water for 15 min each. The substrate was then dried in a vacuum drying oven at 50°C to obtain a pretreated substrate. This pretreated substrate was fixed on a rotating substrate located above the sputtering target. Mg, Ni, and Pd targets with purities of 99.99% were respectively mounted on the sputtering target. The magnetron sputtering system was evacuated to a vacuum level of 1 × 10⁻⁶ using a mechanical pump and a molecular pump. -3 Argon gas with a purity of 99.95% was introduced at a flow rate of 25 sccm and a pressure of 2 Pa. After the gas pressure in the sputtering chamber stabilized, Mg, Ni, and Pd targets were pre-sputtered to remove contaminants from the target surface. The pre-sputtering power of Mg target was 70 W, Ni target was 50 W, and Pd target was 50 W.
[0072] Open the baffles of the Mg target, Ni target and substrate, and deposit the Mg target and Ni target on the substrate by magnetron sputtering co-sputtering. The power of the Mg target is 70W and the power of the Ni target is 50W. Magnetron sputtering co-sputtering is performed for 35 minutes to obtain a polycrystalline composite Mg-Ni alloy thin film.
[0073] With the Mg and Ni targets turned off and the Pd target turned on, the sputtering power was 50W for 60 seconds, resulting in a 10nm protective layer on the surface of the polycrystalline composite Mg-Ni alloy film, thus obtaining the polycrystalline composite Mg...0.78 Ni 0.22 alloy film.
[0074] Polycrystalline composite Mg prepared in Comparative Example 1 0.78 Ni 0.22 The total thickness of the alloy film is approximately 581 nm, and the atomic ratio of Mg to Ni is 78:22.
[0075] Comparative Example 2
[0076] The single-crystal silicon substrate was sequentially sonicated in acetone, anhydrous ethanol, and deionized water for 15 min each. The substrate was then dried in a vacuum drying oven at 50°C to obtain a pretreated substrate. This pretreated substrate was fixed on a rotating substrate located above the sputtering target. Mg, Ti, and Pd targets with purities of 99.99% were respectively mounted on the sputtering target. The magnetron sputtering system was evacuated to a vacuum level of 1 × 10⁻⁶ using a mechanical pump and a molecular pump. -3 Argon gas with a purity of 99.95% was introduced at a flow rate of 25 sccm and a pressure of 2 Pa. After the gas pressure in the sputtering chamber stabilized, Mg, Ti, and Pd targets were pre-sputtered to remove contaminants from the target surface. The pre-sputtering power for Mg target was 70 W, for Ti target it was 50 W, and for Pd target it was 50 W.
[0077] Open the baffles of the Mg target, Ti target and substrate, and deposit the Mg target and Ti target on the substrate by magnetron sputtering co-sputtering. The power of the Mg target is 70W and the power of the Ti target is 50W. Magnetron sputtering co-sputtering is performed for 35 minutes to obtain a polycrystalline composite Mg-Ti alloy thin film.
[0078] With the Mg and Ni targets off and the Pd target on, sputtering power of 50W was used for 60 seconds to form a 10nm protective layer on the surface of the polycrystalline composite Mg-Ti alloy film, thus obtaining the polycrystalline composite Mg... 0.78 Ti 0.22 alloy film.
[0079] Polycrystalline composite Mg prepared in Comparative Example 2 0.78 Ti 0.22 The total thickness of the alloy film is approximately 578 nm, and the atomic ratio of Mg to Ti is 78:22.
[0080] Figure 9 The polycrystalline composite Mg obtained in Comparative Example 1 0.78 Ni 0.22 Dehydrogenation kinetics curves of alloy thin films at different temperatures. Figure 10 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10Alloy thin films and polycrystalline composite Mg prepared in Comparative Example 1 0.78 Ni 0.22 Fitting graph of dehydrogenation activation energy of alloy thin film. Figure 11 For the polycrystalline composite Mg obtained in Comparative Example 2 0.78 Ti 0.22 Dehydrogenation kinetics curves of alloy thin films at different temperatures. Figure 12 The polycrystalline composite Mg obtained in Example 1 0.78 Ni 0.12 Ti 0.10 Alloy thin film, polycrystalline composite Mg obtained in Comparative Example 1 0.78 Ni 0.22 Alloy thin film and polycrystalline composite Mg obtained in Comparative Example 2 0.78 Ti 0.22 Dehydrogenation kinetics of the alloy thin film at 498 K and 0.05 bar H₂. (Source: [Insert Source Here]) Figures 9-12 It is evident that the dehydrogenation activation energy required in Example 1 is only 55.23 kJ / mol H2, which is significantly lower than that in Comparative Example 1 of this invention. Compared to adding Mg2Ni or Ti alone, the combined addition of Mg2Ni and Ti produces a better catalytic effect. The preparation method provided by this invention is simple, reproducible, and can yield hydrogen storage materials with excellent hydrogen storage performance.
[0081] As can be seen from the above embodiments, this invention provides a polycrystalline composite Mg-Ni-Ti alloy thin film, its preparation method, and its application. The Mg-Ni-Ti alloy thin film is prepared by co-sputtering Mg and NiTi targets using magnetron sputtering. The composition and morphology of the film are controlled by adjusting the sputtering power and sputtering time at each target site. In the Mg-Ni-Ti alloy thin film prepared by this invention, the Mg2Ni alloy phase formed by Ni and Mg and elemental Ti exert a synergistic catalytic effect, achieving synergistic modification of nano-sizing, alloying, and catalysis, greatly improving the dehydrogenation performance of the film. The preparation method has a simple film formation process, the obtained film has uniform composition, convenient structure and composition control, and good reproducibility.
[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A polycrystalline composite Mg-Ni-Ti alloy thin film, characterized in that, By atomic percentage: Mg is 68-78%; Ni is 12-17%; the balance is Ti; The preparation method of the polycrystalline composite Mg-Ni-Ti alloy thin film includes the following steps: (1) Install Mg target, NiTi target, Pd target and substrate in ultra-high vacuum magnetron sputtering system respectively, and pre-sputter Mg target, NiTi target and Pd target respectively in working gas atmosphere; (2) Mg target and NiTi target were co-sputtered onto the substrate by magnetron sputtering to obtain a polycrystalline composite Mg-Ni-Ti alloy thin film; The polycrystalline composite Mg-Ni-Ti alloy film contains three phases: Mg2Ni, Ti, and Mg.
2. The polycrystalline composite Mg-Ni-Ti alloy thin film according to claim 1, characterized in that, A protective layer is deposited on the surface of the polycrystalline composite Mg-Ni-Ti alloy thin film; The protective layer is a Pd layer with a thickness of 8~10nm.
3. The method for preparing the polycrystalline composite Mg-Ni-Ti alloy thin film according to any one of claims 1 or 2, characterized in that, Includes the following steps: (1) Install Mg target, NiTi target, Pd target and substrate in ultra-high vacuum magnetron sputtering system respectively, and pre-sputter Mg target, NiTi target and Pd target respectively in working gas atmosphere; (2) Mg target and NiTi target are co-sputtered on the substrate by magnetron sputtering to obtain polycrystalline composite Mg-Ni-Ti alloy thin film.
4. The preparation method according to claim 3, characterized in that, A protective layer is formed by sputtering a Pd target onto the surface of a polycrystalline composite Mg-Ni-Ti alloy thin film.
5. The preparation method according to claim 4, characterized in that, In step (1), the substrate is monocrystalline silicon or aluminum foil; the vacuum level of the ultra-high vacuum magnetron sputtering system is ≤1.0×10⁻⁶. -3 Pa; The working gas is argon, with a flow rate of 22-26 sccm and a pressure of 1.8-2.2 Pa.
6. The preparation method according to claim 4 or 5, characterized in that, In step (1), the power of pre-sputtering of Mg target is 50~70 W, the power of pre-sputtering of NiTi target is 50~70 W, and the power of pre-sputtering of Pd target is 50 W. The Mg and Pd targets were pre-sputtered using DC magnetron sputtering, while the NiTi target was pre-sputtered using radio frequency magnetron sputtering.
7. The preparation method according to claim 6, characterized in that, In step (2), the magnetron sputtering co-sputtering time is 30~60 min; the magnetron sputtering co-sputtering power of Mg target is 50~70 W, and the magnetron sputtering co-sputtering power of NiTi target is 50~70 W.
8. The preparation method according to claim 4, characterized in that, The sputtering time of the Pd target is 60 s; the sputtering power of the Pd target is 50 W.
9. The application of the polycrystalline composite Mg-Ni-Ti alloy thin film according to any one of claims 1 or 2 in hydrogen storage.