A nickel-copper (111) twin film with an in-plane angle of 60° and a preparation method thereof

Abstract

The present invention relates to the technical field of material synthesis, and in particular to a nickel-copper (111) twin film with an in-plane angle of 60° and a preparation method thereof, the method comprising: S1, depositing a metal film on a crystal plane Al2O3 (0001) of a sapphire substrate to obtain a precursor nickel-copper film attached to the sapphire substrate; S2, placing the precursor nickel-copper film in a heating furnace, and performing annealing treatment in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with an out-of-plane direction of 111 preferred orientation, wherein the in-plane crystal domains of the nickel-copper twin film form an angle of 60°. The nickel-copper twin film prepared by the present invention has a strong catalytic performance, can greatly increase the growth rate of graphene, and reduce the cost of batch preparation of graphene single crystal wafers.

Description

Technical Field

[0001] The invention relates to the technical field of material synthesis, and in particular to a nickel-copper (111) twin film with an in-plane angle of 60 degrees and a preparation method thereof. Background Art

[0002] Graphene single crystals have excellent optoelectronic properties and will have great application prospects in the field of microelectronics in the future. At present, the preparation of graphene single crystals mainly uses metal single crystals or metal copper-nickel single crystals as epitaxial substrates to grow graphene, but the preparation process of metal single crystals is complex, the yield is low, and the preparation cost is high, which limits the batch preparation of graphene wafers. Although the copper-nickel twin film is a polycrystalline substrate, it also has a flat surface and super catalytic ability. It can be used as a growth substrate for growing graphene and other two-dimensional materials, and batch preparation of graphene and other wafer-level two-dimensional materials.

[0003] The problem of high graphene wafer preparation cost caused by expensive graphene growth substrate in the prior art is a problem that technicians in this field urgently need to solve. Summary of the invention

[0004] In view of the above problems in the prior art, the purpose of the present invention is to provide a nickel-copper (111) twin film with an in-plane angle of 60° and a preparation method thereof. Sapphire is used as a substrate to prepare the nickel-copper (111) twin film. The obtained nickel-copper (111) twin film has strong catalytic performance, can greatly increase the growth rate of graphene, and reduce the cost of mass production of graphene single crystals.

[0005] In order to solve the above problems, the present invention provides a method for preparing a nickel-copper (111) twin film with an in-plane angle of 60°, comprising the following steps:

[0006] S1, depositing a metal film on the crystal surface Al2O3 (0001) of a sapphire substrate to obtain a precursor nickel-copper film attached to the sapphire substrate;

[0007] S2. Placing the precursor nickel-copper film in a heating furnace and performing annealing treatment in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with a preferred orientation of 111 in the out-of-plane direction, wherein the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

[0008] Furthermore, in the step S1, the deposition thickness is preset in the range of 20-2000 nm during the deposition process.

[0009] Furthermore, the metal film is composed of nickel atoms and copper atoms, and the nickel atoms account for 0 to 30% of the total number of atoms in the metal film.

[0010] Furthermore, the S1 step further includes:

[0011] Heating the sapphire substrate to a preset deposition temperature;

[0012] While heating the sapphire substrate, deposition is performed at a preset deposition rate to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0013] Furthermore, the preset deposition temperature range is 50° C. to 300° C., and the preset deposition rate range is 0.1 nm / min to 1000 nm / min.

[0014] Furthermore, the step S1 specifically includes: depositing nickel atoms and copper atoms simultaneously, or depositing nickel atoms first and then copper atoms, or depositing copper atoms first and then nickel atoms.

[0015] Furthermore, in the step S2, the annealing treatment includes a heat preservation stage, an annealing stage and a cooling stage.

[0016] Furthermore, the step S2 specifically includes:

[0017] In the insulation stage, the insulation temperature ranges from 300°C to 600°C, the insulation time ranges from 10min to 180min, and the first heating rate ranges from 0.1°C / min to 200°C / min;

[0018] In the annealing stage, the annealing temperature ranges from 700°C to 1100°C, the annealing time ranges from 10min to 180min, and the second heating rate ranges from 0.1°C / min to 200°C / min;

[0019] In the cooling stage, the cooling rate ranges from 0.01°C / min to 200°C / min.

[0020] Furthermore, in the S2 step, during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 10-1500sccm:1-50sccm; during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the cooling process in the temperature reduction stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm.

[0021] The present invention also protects a nickel-copper (111) twin film with an in-plane angle of 60°, which is prepared by the preparation method of a nickel-copper (111) twin film with an in-plane angle of 60° as described in any one of the above embodiments, wherein the out-of-plane direction of the nickel-copper twin film is a 111 preferred orientation, and the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

[0022] Due to the above technical solution, the present invention has the following beneficial effects:

[0023] The invention provides a nickel-copper (111) twin film with an in-plane angle of 60° between crystal domains and a preparation method thereof. The nickel-copper (111) twin film with an in-plane angle of 60° prepared by the above method has strong catalytic performance, can greatly increase the growth rate of graphene, and reduce the cost of mass production of graphene single crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a flow chart of a method for preparing a nickel-copper twin film provided by an embodiment of the present invention;

[0026] Figure 2 This is a macroscopic image of the nickel-copper (111) twin film provided in Example 1 of the present invention;

[0027] Figure 3 is an optical microscope image of the nickel-copper (111) twin film provided in Example 1 of the present invention;

[0028] Figure 4 is an electron microscope image of the nickel-copper (111) twin film provided in Example 1 of the present invention;

[0029] Figure 5 This is an atomic force microscope image of the nickel-copper (111) twin film provided in Example 1 of the present invention;

[0030] Figure 6 is an X-ray diffraction pattern of the nickel-copper (111) twin film in the out-of-plane direction provided by Example 1 of the present invention;

[0031] Figure 7 is an X-ray diffraction pattern of the nickel-copper (111) twin film in the in-plane direction provided by Example 1 of the present invention;

[0032] Figure 8This is a macro wafer image of the nickel-copper (111) twinned thin film provided in Example 2 of the present invention;

[0033] Fig. 9 This is a macro wafer image of the nickel-copper (111) twin film provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0036] Embodiment 1

[0037] This embodiment 1 provides a nickel-copper (111) twin film with an in-plane angle of 60° and a preparation method thereof, such as Figure 1 As shown, the preparation method comprises the following steps:

[0038] S1, depositing a metal film on the crystal surface Al2O3 (0001) of a sapphire substrate to obtain a precursor nickel-copper film attached to the sapphire substrate;

[0039] S2, placing the precursor nickel-copper film in a heating furnace, and annealing it in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with a preferred orientation of 111 in the out-of-plane direction, and an angle of 60° between the in-plane crystal domains of the nickel-copper twin film. Specifically, the sapphire substrate is used for epitaxial matching with the alloy atoms of the metal film, and the size of the sapphire substrate is 2 to 8 inches.

[0040] Preferably, the sapphire substrate has a size of 4 inches.

[0041] Specifically, before the step S1, a sapphire substrate is provided, which specifically includes: placing the sapphire substrate in isopropanol for ultrasonic cleaning for 20 minutes, and then purging it clean with a high-purity nitrogen gun.

[0042] Specifically, the metal film is composed of nickel atoms and copper atoms, and the nickel atoms account for 0 to 30% of the total number of atoms in the metal film, which can ensure the catalytic performance of the metal film, wherein the purity of the nickel atoms and the copper atoms are both 99.9999%, therefore, the total number of the nickel atoms and the copper atoms accounts for 99.9999% of the total number of atoms in the metal film.

[0043] Preferably, the nickel atoms account for 15% of the total number of atoms in the metal film.

[0044] Specifically, in the S2 step, the Al2O3 (0001) refers to the C-plane of sapphire, also known as sapphire (0001). Experiments have shown that neither the R-plane nor the A-plane of sapphire can achieve consistent out-of-plane orientation of the metal film.

[0045] Specifically, in the step S1, the preset deposition thickness range is 20-2000 nm during the deposition process. The preset thickness can ensure that the precursor nickel-copper film will not be damaged during the annealing process while ensuring that the out-of-plane orientation of the film is consistent.

[0046] Preferably, the preset deposition thickness is 500 nm.

[0047] Specifically, the S1 step further includes:

[0048] Heating the sapphire substrate to a preset deposition temperature;

[0049] While heating the sapphire substrate, deposition is performed at a preset deposition rate to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0050] Furthermore, the preset deposition temperature range is 50° C. to 300° C., the deposition heating method adopted is radiation heating or resistance heating, and the preset deposition rate range is 0.1 nm / min to 1000 nm / min.

[0051] Furthermore, in the step S1, deposition is performed by magnetron sputtering.

[0052] Furthermore, the step S1 specifically includes: depositing nickel atoms and copper atoms simultaneously, or depositing nickel atoms first and then copper atoms, or depositing copper atoms first and then nickel atoms.

[0053] Specifically, in the step S1, the sapphire substrate is deposited at room temperature with a deposition rate of 100 nm / min, argon gas of 0.1 Pa, and a power of 500 W to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0054] Specifically, in the step S2, the mixed atmosphere of argon and hydrogen can ensure the texturing of the metal film, and can not only protect the metal film from being oxidized during the annealing process, but also increase the kinetic energy of the movement of nickel and copper atoms.

[0055] Specifically, in the step S2, the annealing treatment includes a heat preservation stage, an annealing stage and a cooling stage.

[0056] Furthermore, in the step S2,

[0057] In the insulation stage, the insulation temperature ranges from 300°C to 600°C, the insulation time ranges from 10min to 180min, and the first heating rate ranges from 0.1°C / min to 200°C / min;

[0058] In the annealing stage, the annealing temperature ranges from 700°C to 1100°C, the annealing time ranges from 10min to 180min, and the second heating rate ranges from 0.1°C / min to 200°C / min;

[0059] In the cooling stage, the cooling rate ranges from 0.01°C / min to 200°C / min.

[0060] Furthermore, in the S2 step, during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 10-1500sccm:1-50sccm; during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the cooling process in the temperature reduction stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm.

[0061] Preferably, the parameters of the annealing treatment in this embodiment are:

[0062] In the step S2, the holding temperature is 500° C., the holding time is 60 min, the first heating rate is 20° C. / min, the flow ratio of argon to hydrogen during the heating process in the holding stage is 300 sccm:10 sccm, and the flow ratio of argon to hydrogen during the holding process in the holding stage is 300 sccm:10 sccm;

[0063] In the step S2, the annealing temperature is 1000°C, the annealing time is 60 minutes, the second heating rate is 20°C / min, and during the heating process in the annealing stage, the flow ratio of argon gas to hydrogen gas is 300sccm:10sccm; during the heat preservation process in the annealing stage, the flow ratio of argon gas to hydrogen gas is 300sccm:10sccm;

[0064] In the step S2, the cooling rate is 10°C / min, and in the cooling stage, the flow ratio of argon gas to hydrogen gas is 300sccm:10sccm.

[0065] like Figure 2 As shown, the above-mentioned preparation method is used to prepare a nickel-copper (111) twin film with an in-plane angle of 60°. The nickel-copper twin film is preferentially oriented in the out-of-plane direction 111, and the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

[0066] Specifically, the morphology of the prepared nickel-copper (111) twin film with an in-plane angle of 60° was characterized: Figure 3 is a scanning optical microscope image of the nickel-copper (111) twin film. Figure 3 It can be seen that the nickel-copper (111) twin film is a flat surface composed of a large number of grains; Figure 4 is a scanning electron microscope image of the nickel-copper (111) twin film. Figure 4 It can be seen that under high magnification, a large number of grain boundaries exist on the surface of the nickel-copper (111) twin film; Figure 5 is an atomic force microscope photo of the nickel-copper (111) twin film. Figure 5 It can be seen that the grain boundaries of the nickel-copper (111) twin film can be observed, and the grain boundary interface is a long strip of crystal domains with an inverted "trapezoidal" structure and a flat inner surface;

[0067] according to Figures 3 to 5 According to the analysis, the nickel-copper (111) twin film prepared by the above method has a smooth surface with a large number of grain boundaries.

[0068] Specifically, the orientation of the prepared nickel-copper (111) twin film with an in-plane angle of 60° was characterized: Figure 6is the out-of-plane X-ray diffraction pattern of the nickel-copper (111) twin film, Figure 6 It can be observed that the peak at 43.5° is a nickel-copper (111) alloy orientation peak, indicating that the nickel-copper alloy film is a 111-oriented film; Figure 7 is the in-plane X-ray diffraction pattern of the nickel-copper (111) twin film, Figure 7 It can be observed that Figure 7 There are six peaks in it, including two sets of diffraction peaks, each set of diffraction is 120° to each other, so it is three-fold symmetric; the angle between the two sets of diffraction peaks is 60°, which proves that the prepared film is a nickel-copper (111) twin film, and the crystal domains in the nickel-copper (111) twin film have an in-plane rotation angle of 60°.

[0069] Embodiment 2

[0070] The second embodiment provides a nickel-copper (111) twinned film with an in-plane angle of 60° and a preparation method thereof, the preparation method comprising the following steps:

[0071] S1, depositing a metal film on the crystal surface Al2O3 (0001) of a sapphire substrate to obtain a precursor nickel-copper film attached to the sapphire substrate;

[0072] S2. Placing the precursor nickel-copper film in a heating furnace and performing annealing treatment in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with a preferred orientation of 111 in the out-of-plane direction, wherein the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

[0073] Specifically, the sapphire substrate is used for epitaxial matching with alloy atoms of the metal film, and the size of the sapphire substrate is 2 to 8 inches.

[0074] Preferably, the sapphire substrate has a size of 4 inches.

[0075] Specifically, before the step S1, a sapphire substrate is provided, which specifically includes: placing the sapphire substrate in isopropanol for ultrasonic cleaning for 30 minutes, and then purging it clean with a high-purity nitrogen gun.

[0076] Specifically, the metal film is composed of nickel atoms and copper atoms, and the nickel atoms account for 0 to 30% of the total number of atoms in the previous metal film, which can ensure the catalytic performance of the metal film, wherein the purity of the nickel atoms and the copper atoms are both 99.9999%, therefore, the total number of the nickel atoms and the copper atoms accounts for 99.9999% of the total number of atoms in the metal film.

[0077] Preferably, the nickel atoms account for 10% of the total number of atoms in the metal film.

[0078] Specifically, in the S2 step, the Al2O3 (0001) refers to the C-plane of sapphire, also known as sapphire (0001). Experiments have shown that neither the R-plane nor the A-plane of sapphire can achieve consistent out-of-plane orientation of the alloy film.

[0079] Specifically, in the step S1, the preset deposition thickness range is 20-2000 nm during the deposition process. The preset thickness can ensure that the metal film will not be damaged during the annealing process while ensuring that the out-of-plane orientation of the alloy film is consistent.

[0080] Preferably, the preset deposition thickness is 100 nm.

[0081] Specifically, the S1 step further includes:

[0082] Heating the sapphire substrate to a preset deposition temperature;

[0083] While heating the sapphire substrate, deposition is performed at a preset deposition rate to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0084] Furthermore, the preset deposition temperature range is 50° C. to 300° C., the deposition heating method adopted is radiation heating or resistance heating, and the preset deposition rate range is 0.1 nm / min to 1000 nm / min.

[0085] Furthermore, in the step S1, deposition is performed by electron beam evaporation.

[0086] Furthermore, the step S1 specifically includes: depositing nickel atoms and copper atoms simultaneously, or depositing nickel atoms first and then copper atoms, or depositing copper atoms first and then nickel atoms.

[0087] Specifically, in the step S1, the sapphire substrate is deposited at 20° C., with a deposition rate of 100 nm / min, argon gas of 0.1 Pa, and a power of 50 W to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0088] Specifically, in the step S2, the mixed atmosphere of argon and hydrogen can ensure the texturing of the precursor nickel-copper film, and can not only protect the precursor nickel-copper film from oxidation during the annealing process, but also increase the kinetic energy of the movement of nickel-copper atoms.

[0089] Specifically, in the step S2, the annealing treatment includes a heat preservation stage, an annealing stage and a cooling stage;

[0090] Furthermore, in the insulation stage, the insulation temperature ranges from 300°C to 600°C, the insulation time ranges from 10min to 180min, and the first heating rate ranges from 0.1°C / min to 200°C / min;

[0091] In the annealing stage, the annealing temperature ranges from 700°C to 1100°C, the annealing time ranges from 10min to 180min, and the second heating rate ranges from 0.1°C / min to 200°C / min;

[0092] In the cooling stage, the cooling rate ranges from 0.01°C / min to 200°C / min.

[0093] Furthermore, in the S2 step, during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 10-1500sccm:1-50sccm; during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the cooling process in the temperature reduction stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm.

[0094] Preferably, the parameters of the annealing treatment in this embodiment are:

[0095] In the S2 step, the insulation temperature is 400°C, the insulation time is 120min, the first heating rate is 10°C / min, and during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 300sccm:20sccm, and during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 300sccm:20sccm; in the S2 step, the annealing temperature is 800°C, the annealing time is 30min, the second heating rate is 10°C / min, during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 300sccm:20sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 300sccm:20sccm;

[0096] In the step S2, the cooling rate is 20°C / min, and in the cooling stage, the flow ratio of argon gas to hydrogen gas is 300sccm:20sccm.

[0097] like Figure 8As shown, the above-mentioned preparation method is used to prepare a nickel-copper (111) twin film with an in-plane angle of 60°, the out-of-plane direction of the nickel-copper twin film is a 111 preferred orientation, and the in-plane angle between the crystal domains of the nickel-copper twin film is 60°.

[0098] Embodiment 3

[0099] The third embodiment provides a nickel-copper (111) twin film with an in-plane angle of 60° and a preparation method thereof. The preparation method comprises the following steps:

[0100] S1, depositing a metal film on the crystal surface Al2O3 (0001) of a sapphire substrate to obtain a precursor nickel-copper film attached to the sapphire substrate;

[0101] S2. Placing the precursor nickel-copper film in a heating furnace and performing annealing treatment in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with a preferred orientation of 111 in the out-of-plane direction, wherein the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

[0102] Specifically, the sapphire substrate is used for epitaxial matching with alloy atoms of the metal film, and the size of the sapphire substrate is 2 to 8 inches.

[0103] Preferably, the sapphire substrate has a size of 8 inches.

[0104] Specifically, before the step S1, a sapphire substrate is provided, which specifically includes: placing the sapphire substrate in isopropanol for ultrasonic cleaning for 30 minutes, and then purging it clean with a high-purity nitrogen gun.

[0105] Specifically, in the S1 step, the metal film is composed of nickel atoms and copper atoms, and the nickel atoms account for 0 to 30% of the total number of atoms in the previous metal film, which can ensure the catalytic performance of the metal film, wherein the purity of the nickel atoms and the copper atoms are both 99.9999%, therefore, the total number of the nickel atoms and the copper atoms accounts for 99.9999% of the total number of atoms in the metal film.

[0106] Preferably, the nickel atoms account for 30% of the total number of atoms in the metal film.

[0107] Specifically, in the S2 step, the Al2O3 (0001) refers to the C-plane of sapphire, also known as sapphire (0001). Experiments have shown that neither the R-plane nor the A-plane of sapphire can achieve consistent out-of-plane orientation of the alloy film.

[0108] Specifically, in the step S1, the preset deposition thickness range is 20-2000 nm during the deposition process. The preset thickness can ensure that the metal film will not be damaged during the annealing process while ensuring that the out-of-plane orientation of the alloy film is consistent.

[0109] Preferably, the preset deposition thickness is 1000 nm.

[0110] Specifically, the S1 step further includes:

[0111] Heating the sapphire substrate to a preset deposition temperature;

[0112] While heating the sapphire substrate, deposition is performed at a preset deposition rate to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0113] Furthermore, the preset deposition temperature range is 50° C. to 300° C., the deposition heating method adopted is radiation heating or resistance heating, and the preset deposition rate range is 0.1 nm / min to 1000 nm / min.

[0114] Furthermore, in the step S1, deposition is performed by magnetron sputtering.

[0115] Furthermore, the step S1 specifically includes: depositing nickel atoms and copper atoms simultaneously, or depositing nickel atoms first and then copper atoms, or depositing copper atoms first and then nickel atoms.

[0116] Specifically, in the step S1, the sapphire substrate is deposited at 150° C., with a deposition rate of 100 nm / min, argon gas of 0.1 Pa, and a power of 100 W to obtain a precursor nickel-copper film attached to the sapphire substrate.

[0117] Specifically, in the step S2, the mixed atmosphere of argon and hydrogen can ensure the texturing of the precursor nickel-copper film, and can not only protect the precursor nickel-copper film from oxidation during the annealing process, but also increase the kinetic energy of the movement of nickel-copper atoms.

[0118] Specifically, in the step S2, the annealing treatment includes a heat preservation stage, an annealing stage and a cooling stage.

[0119] Furthermore, in the insulation stage, the insulation temperature ranges from 300°C to 600°C, the insulation time ranges from 10min to 180min, and the first heating rate ranges from 0.1°C / min to 200°C / min;

[0120] In the annealing stage, the annealing temperature ranges from 700°C to 1100°C, the annealing time ranges from 10min to 180min, and the second heating rate ranges from 0.1°C / min to 200°C / min;

[0121] In the cooling stage, the cooling rate ranges from 0.01°C / min to 200°C / min.

[0122] Furthermore, in the S2 step, during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 10-1500sccm:1-50sccm; during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the cooling process in the temperature reduction stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm.

[0123] Preferably, the parameters of the annealing treatment in this embodiment are:

[0124] In the step S2, the holding temperature is 600° C., the holding time is 30 min, the first heating rate is 15° C. / min, the flow ratio of argon to hydrogen during the heating process in the holding stage is 300 sccm:10 sccm, and the flow ratio of argon to hydrogen during the holding process in the holding stage is 300 sccm:10 sccm;

[0125] In the step S2, the annealing temperature is 1000°C, the annealing time is 30 minutes, the second heating rate is 15°C / min, and during the heating process in the annealing stage, the flow ratio of argon gas to hydrogen gas is 300sccm:30sccm; during the heat preservation process in the annealing stage, the flow ratio of argon gas to hydrogen gas is 300sccm:30sccm;

[0126] In the step S2, the cooling rate is 50°C / min, and in the cooling stage, the flow ratio of argon gas to hydrogen gas is 300sccm:30sccm.

[0127] like Fig. 9 As shown, the above-mentioned preparation method is used to prepare a nickel-copper (111) twin film with an in-plane angle of 60°, the out-of-plane direction of the nickel-copper twin film is a 111 preferred orientation, and the in-plane angle between the crystal domains of the nickel-copper twin film is 60°.

[0128] The methods of Examples 1-3 all prepared nickel-copper (111) twin films with an in-plane angle of 60°, which have strong catalytic properties, can greatly increase the growth rate of graphene, and reduce the cost of mass production of graphene single crystals.

[0129] The above description has fully disclosed the specific embodiments of the present invention. It should be pointed out that any changes made by those skilled in the art to the specific embodiments of the present invention do not deviate from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the above specific embodiments.

Claims

1. A method for preparing a nickel-copper (111) twin film with an in-plane angle of 60°, characterized in that: The steps include: S1, heating the sapphire substrate to a preset deposition temperature, while heating the sapphire substrate, performing deposition at a preset deposition rate to deposit a precursor nickel-copper film attached to the sapphire substrate, wherein the preset deposition thickness range is 20-2000nm, the preset deposition temperature range is 50°C to 300°C, and the preset deposition rate range is 0.1nm / min to 1000nm / min; S2. Placing the precursor nickel-copper film in a heating furnace and performing annealing treatment in a mixed atmosphere of argon and hydrogen to obtain a nickel-copper twin film with a preferred orientation of 111 in the out-of-plane direction, wherein the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

2. The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° according to claim 1, characterized in that: The precursor nickel-copper film is composed of nickel atoms and copper atoms, and the nickel atoms account for 0-30% of the total number of atoms in the precursor nickel-copper film.

3. The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° according to claim 1, characterized in that: The step S1 specifically includes: depositing nickel atoms and copper atoms simultaneously, or depositing nickel atoms first and then copper atoms, or depositing copper atoms first and then nickel atoms.

4. The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° according to claim 1, characterized in that: In the step S2, the annealing treatment includes a heat preservation stage, an annealing stage and a cooling stage.

5. The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° according to claim 4, characterized in that: The step S2 specifically includes: In the insulation stage, the insulation temperature ranges from 300°C to 600°C, the insulation time ranges from 10min to 180min, and the first heating rate ranges from 0.1°C / min to 200°C / min; In the annealing stage, the annealing temperature ranges from 700°C to 1100°C, the annealing time ranges from 10min to 180min, and the second heating rate ranges from 0.1°C / min to 200°C / min; In the cooling stage, the cooling rate ranges from 0.01°C / min to 200°C / min.

6. The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° according to claim 4, characterized in that: In the S2 step, during the heating process in the insulation stage, the flow ratio of argon and hydrogen is 10-1500sccm:1-50sccm; during the insulation process in the insulation stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the heating process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; during the insulation process in the annealing stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm; in the cooling stage, the flow ratio of argon and hydrogen is 100-500sccm:1-100sccm.

7. A nickel-copper (111) twin film with an in-plane angle of 60°, characterized in that: The method for preparing a nickel-copper (111) twin film with an in-plane angle of 60° as described in any one of claims 1 to 6 is used for preparation, wherein the out-of-plane direction of the nickel-copper twin film is 111 preferentially oriented, and the in-plane crystal domains of the nickel-copper twin film form an angle of 60°.

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