Multilayer composite material

Abstract

A multilayer layered composite material piece (10), the multilayer layered composite material piece comprising: a conductive substrate (1); an electrically conductive buffer structure (2) consisting of one or more non-oxide films, the non-oxide films being made of a metal nitride; and a superconducting film (3) which is composed of Fe (Se, Te). Wherein Fe (Se, Te) is a compound comprising an Fe atom and at least a chalcogen anion, the chalcogen anion consisting of an Se atom and a Te atom in a variable ratio; wherein the conductive non-oxide film (2) is interposed between the conductive base material (1) and the superconducting film (3).

Description

Technical Field

[0001] This invention relates to a superconducting multilayered composite material and related methods for preparing the material.

[0002] Specifically, the present invention relates to a flexible layered superconductor, which is formed by a conductive substrate, an iron-based superconducting (IBS) film (belonging to the subclass of iron-sulfur compounds) and a film sandwiched between the conductive substrate and the iron-based superconducting (IBS) film, wherein the film is made of a conductive but non-oxide, i.e., ceramic material. Background Technology

[0003] In this specification and its appended claims, unless otherwise expressly stated, certain terms and expressions shall have the meanings expressed in the following definitions.

[0004] "Fe(Se,Te)" refers to iron chalcogenides, which are compounds consisting of iron atoms and at least chalcogenide anions composed of selenium and tellurium atoms in a variable ratio.

[0005] The "nominal composition" of Fe(Se,Te) refers to the stoichiometric ratio of the elements contained in the membrane precursor material, which is determined by the nominal composition unless otherwise measured.

[0006] The term "layered" refers to a material component with a very small thickness in at least one dimension on a plane, for example, a total thickness between 50 μm and 300 μm, in the context of superconducting multilayered composite materials.

[0007] "Normal phase" refers to the superconducting film at its critical temperature (T). C In the above states, the superconducting film changes from the properties of a superconductor to the properties of a simple conductor.

[0008] "Four-terminal sensing technology" refers to a technique for measuring the physical properties of a material. This technique involves setting four contacts on a sample, measuring the potential at one pair of contacts while simultaneously transmitting current between the other two contacts.

[0009] "Target" refers to a sample of material intended to be deposited on a substrate in the form of a thin film. During thin film deposition, an energy source is typically used to bombard the target, causing it to decompose and allowing it to grow on the substrate through recombination (whether spontaneous or non-spontaneous).

[0010] The recent discovery of superconductivity in iron-based compounds (IBS)[1] has aroused great interest in the scientific community: within a few months, many superconducting compounds belonging to this series have been prepared and characterized.

[0011] Due to the simple crystal structure of Fe(Se,Te) compounds (belonging to the iron-sulfur group subclass), which is the simplest among iron-based superconducting compounds, and the low toxicity of the elements composing Fe(Se,Te) compounds, they are among the most widely studied compounds [2, 3, 4]. When selenium is partially replaced by tellurium (50%), the critical temperature Tc... c (That is, when the temperature is below the critical temperature T) c Under these conditions, the material becomes a superconductor (with zero resistance) and can reach a maximum resistance of approximately 14K to 15K. The fabrication of Fe(Se,Te) epitaxial films on single-crystal substrates is crucial for studying the intrinsic properties of this compound [5, 6, 7, 8]. In this film, T... c It can be higher than the values ​​obtained in bulk compounds, up to about 21K [9].

[0012] The reason for this behavior is that the lattice adaptation between the substrate and the film causes lattice compression deformation

[10] . In the form of single crystal or epitaxial film, this material can transmit approximately 10 without loss in a magnetic field with a magnetic field of up to 30 Tesla at liquid helium temperature. 5 Acm -2 The current [11, 12, 13].

[0013] Given these characteristics, the technical applications of this material can be carried out in high magnetic fields and low operating temperatures, such as melting, accelerators for large particles, and nuclear magnetic resonance (NMR).

[0014] Most of these systems require the fabrication of superconducting material components in the form of wires and strips for implementing cables. It is important to note that even for implementing strips, layered material components that can be further processed are required.

[0015] Compared to the most commonly used superconducting cables (such as Nb3Sn-based cables), Fe(Se,Te)-based cables can be used in higher magnetic fields. High critical temperature superconductors (HTS) (such as cuprate YBCO compounds) can also achieve similar performance, but due to their complex structure and the resulting complex manufacturing process, the production cost of HTS-based conductors is high, thus limiting their application to date

[14] .

[0016] Currently, the most common methods for manufacturing superconducting wires and tapes are powder-filled tube (PIT) metallurgy and thin-film technology-based processes. However, the high reactivity of the elements limits the process conditions, thus affecting the final performance

[17] , making it almost impossible to produce Fe(Se,Te) wires using PIT technology[15, 16]. In contrast, thin-film deposition technology is suitable for manufacturing Fe(Se,Te)-based conductors[18, 19].

[0017] Currently known superconducting layered materials are conductors employing a layered structure. This structure includes: a metallic support called the substrate, typically nickel foil or a nickel alloy, which must ensure the flexibility of the strip and ultimately work synergistically with the superconducting film to stabilize it; the superconducting film; and one or more intermediate films called "buffer layers" (BLs), whose primary purpose is to prevent atomic diffusion from the substrate to the superconducting film. Among the layers constituting the BL structure, the films in direct contact with the superconducting film must ensure optimal chemical and structural compatibility to promote the epitaxial growth of the superconducting film itself.

[0018] Subsequently, known superconducting layered materials are refined by covering the superconducting film with a protective film (in the case of HTS, a protective film made of silver) and a coating (i.e., a stabilizing film) typically made of copper, to ensure the thermal and electrical stability of the superconducting film. The resulting structure is internationally known as a "coated conductor".

[0019] The difference between the two main fabrication techniques for superconducting layered materials lies in the characteristics of the metal support used as the substrate. If the substrate has a cubic texture, i.e., the grains constituting it are biaxially oriented, the process is called RABiTS [20, 21]. After thermomechanical treatment, the substrate (usually a nickel-based and / or copper-based alloy) forms a cubic texture, which is then transferred to the superconducting film via BL using epitaxial thin film growth techniques.

[0020] When using IBAD (ion beam assisted deposition) technology, the substrate is an alloy without texture features, and the cubic texture is induced by ion bombardment in one of the films contained in the BL structure during the deposition process

[22] .

[0021] One problem with IBAD technology is that the BL structure is very complex: an oxide film with an amorphous structure is used to prevent diffusion from the substrate and to provide a flat surface as well as a layer above the film grown using IBAD technology to ensure chemical and structural compatibility with the superconducting layer.

[0022] The feasibility of Fe(Se,Te)-based superconducting layered materials was verified using IBAD and RABiTS techniques [13,23, 24, 25, 26]. In particular, the study showed that Fe(Se,Te) films can be obtained using a single buffer layer [18,27, 28], or films with more irregular cubic textures than those required for HTS films can generally be obtained

[13] .

[0023] In currently known superconducting layered materials, the stabilizing film protects the superconducting film in the event of an unexpected transition to the normal phase.

[0024] The normal phase is a dissipative phase, and the temperature rise caused by the Joule effect can lead to severe damage. To eliminate the current in the superconducting film under normal conditions, a metal with low resistance can be used to contact the superconducting film.

[0025] If the superconducting film (BL) is made of insulating material, one or more layers of metal material need to be deposited on the superconducting film to form a stabilizing film and a protective film.

[0026] By using conductive BL, the thickness of the stabilizing film can be reduced, or even removed.

[0027] Furthermore, the protective film can be made from cheaper materials. In principle, this will reduce the cost of the finished product while improving performance.

[0028] Through IBAD technology, the BL structure always includes an insulating material layer.

[0029] In contrast, RABiTS technology allows the use of one or more conductive BLs. Previously, conductive oxide BLs were investigated to develop HTS bands [29, 30, 31]. However, epitaxial growth of HTS films requires high temperatures above 800°C and an oxygen-rich atmosphere.

[0030] Because oxygen diffuses through BL, undesirable non-conductive oxides often appear at the substrate interface, which reduces the effectiveness of electrical connections and the substrate when BL is also used as a stabilizer.

[0031] In the past, TiN, a conductive ceramic material, has been studied for use in BL (polymeric ion exchange) because of its ability to prevent small metal ions from diffusing from the substrate to the superconducting film, and it can be used to develop RABiTS substrates based on copper (Cu) or copper alloys [32, 33, 34, 35]. (In SZWACHTA, G.; GAJEWSKA, M.; K...) C, S. Growth and Characterization ofPulsed-Laser Deposited Tin Thin Films on Cube-Textured Copper at DifferentTemperatures. Archives of Metallurgy and Materials In 2016, 61.2B: 1031-1038, different methods for growing TiN on Cu were analyzed, and it was found that TiN is very sensitive to temperature conditions and pretreatment procedures. In fact, TiN reacts very violently with oxygen above 400 °C

[36] , so it is necessary to protect it, but this makes the BL structure for HTS complex and unattractive because it contains a layer of TiN.

[0032] One of the main challenges in realizing superconducting layered structures using conductive non-oxide (BL) materials (especially when using TiN) is avoiding oxide formation at the interface between the substrate and the superconducting film. Oxide formation between the substrate and the superconducting film reduces the electrical connection between them and also decreases the effectiveness of the substrate as a stabilizer.

[0033] Of all the BL materials used for growing Fe(Se,Te) films, cerium oxide (CeO2) represents the most promising option, capable of growing superconducting films of excellent quality [13, 26, 37].

[0034] Epitaxial growth of CeO2 films (or more generally, ceramic oxide films) requires the presence of oxygen

[38] . Disadvantageously, when CeO2 films are used as monolayer buffer layers, special strategies are required to avoid substrate oxidation, which complicates the production process: for example, by growing bilayer CeO2 by depositing the first layer in a vacuum or reducing atmosphere

[39] .

[0035] US Patent No. 6,784,139 B1 relates to nitrogen-containing conductive oxides and conductive non-oxides (BLs). This document primarily explores the compatibility between conductive substrates and BLs. According to some implementations, the invention includes superconducting films, particularly yttrium barium copper oxide (YBCO) grown over BLs. This document emphasizes the importance of lattice compatibility required to achieve good electrical conduction between superconductors and conductive substrates.

[0036] It is well known that certain oxides, especially CeO2, meet the requirements of lattice compatibility. However, during the deposition of conductive oxides, undesirable non-conductive oxides may be generated, thereby reducing the effectiveness of the conductive substrate and decreasing the electrical conductivity between superconductors and conductors. Nitrates have been proposed as non-oxide BLs, to be used in combination with nitrides or other oxides in order to obtain structures with good compatibility with YBCO. Unfortunately, this approach is not applicable to other types of superconductors.

[0037] Therefore, it is of great importance to develop a superconducting multilayer composite material with a simple structure, good stability, and low production cost.

[0038] Another issue involves the need to coat the superconducting film to prevent damage from temperature variations and magnetic fields. This coating must be suitable both for protecting the superconductor and for substantially maintaining its properties in terms of conductivity and magnetic field generation. (See WEI, Shaoqing, et al. First performance test of FeSe0.5Te0.5-coated conductor coil under high magnetic fields.) Superconductor Science and Technology In 2023, 36.4: 04LT01, researchers conducted different comparative tests to determine the protective coating of Fe(Se,Te) coated conductors obtained using IBAD technology, thereby verifying the suitability of such superconductors for high-intensity magnetic field applications.

[0039] The technical problem behind this invention is to provide a superconducting multilayer composite material and a related method for producing the superconducting multilayer composite material, thereby overcoming the disadvantages mentioned in the prior art, which involve the formation of undesirable oxides at the interfaces between the substrate and the BL and between the BL and the superconducting film, and / or the use of complex and expensive production methods. Summary of the Invention

[0040] In the first respect, this problem can be solved by superconducting multilayered composite material parts as defined in appended claim 1.

[0041] The superconducting multilayer composite material includes: a conductive substrate; an electrically conductive buffer structure composed of one or more non-oxide films made of metal nitrides; and a superconducting film composed of Fe(Se,Te).

[0042] Preferably, the metal nitride is selected from the following: TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN and / or combinations thereof.

[0043] More preferably, the metal nitride is TiN.

[0044] Specifically, a conductive non-oxide film is sandwiched between the conductive substrate and the superconducting film.

[0045] Preferably, the superconducting multilayered composite material is flexible.

[0046] The main advantage of the superconducting multilayered composite material according to the present invention lies in the fact that it provides a conductive layered material, preferably having a conductive buffer structure consisting of only one non-oxide film; and a conductive substrate that can perform a dual function, namely, providing flexibility to the superconducting multilayered composite material and stabilizing the material in the event of an accidental transition to the normal phase.

[0047] Another advantage lies in the non-oxide nature of the membrane structure, which consists of one or more metal nitrides and acts as a buffer layer. In fact, conductive nitrides are not oxides, so they can be grown in a controlled atmosphere lacking O2, thus preventing the formation of non-conductive oxides at the substrate interface. Indeed, the presence of non-conductive oxides at the interface reduces the electrical connection between the superconducting film and the conductive substrate, thereby reducing the effectiveness of the substrate itself as a stabilizing layer.

[0048] It should be understood that the superconducting film composed of Fe(Se,Te) is a non-oxide superconductor. Therefore, during the deposition of this superconducting film, the formation of non-conductive oxides at the interface between the superconducting film and the buffer structure, as well as at the interface between the buffer structure and the conductive substrate, should be avoided.

[0049] Preferably, the superconducting film made of Fe(Se,Te) comprises a plurality of epitaxial layers grown on a buffer structure, the epitaxial layers being made of Fe(Se,Te).

[0050] Each of the plurality of layers can be grown at different temperatures, preferably between 200°C and 450°C.

[0051] Preferably, the superconducting film comprises: a first epitaxial layer grown on a buffer structure, the first epitaxial layer being made of Fe(Se,Te); and a second epitaxial layer grown on the first epitaxial layer, the second epitaxial layer being made of Fe(Se,Te).

[0052] The presence of the first and second epitaxial layers improves the crystallinity of the first layer, while the second layer provides superconductivity between the buffer structure and the superconducting layer, thus maintaining good superconductivity and low resistivity in the normal phase.

[0053] The first epitaxial layer may not be superconducting because it is arranged to improve the crystal structure of the first layer, while the second epitaxial layer is arranged to ensure superconductivity.

[0054] Preferably, the first epitaxial layer is grown at a temperature between 300°C and 450°C, more preferably at a temperature of 400°C; the second epitaxial layer is grown at a temperature between 200°C and 300°C, more preferably at a temperature of 250°C.

[0055] Advantageously, the temperature is higher when growing the first epitaxial layer and lower when growing the second epitaxial layer, thus allowing for examination of the crystal structure and stoichiometric composition of Fe(Se,Te).

[0056] Another advantage is that by growing a first epitaxial layer with higher crystallinity at a higher temperature, the energy consumption of superconducting film deposition made of Fe(Se,Te) is reduced, and then the temperature is lowered during the growth of a second epitaxial layer with inherent lattice compatibility, since the second epitaxial layer is set on the same material and therefore high temperature is not required to improve lattice compatibility.

[0057] In a second aspect of the invention, such problems are solved by a method for producing superconducting multilayered composite material parts as defined in appended claim 13.

[0058] The method includes: setting a conductive substrate on which an electrically conductive buffer structure consisting of one or more non-oxide films made of metal nitrides must be grown.

[0059] Once the buffer structure is grown, a superconducting film made of Fe(Se,Te) is grown on the buffer structure.

[0060] As with the case of layered composite parts, the metal nitride is preferably selected from the following: TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN and / or combinations thereof.

[0061] More preferably, the metal nitride is TiN.

[0062] Advantageously, TiN maintains its conductivity and bonding with the substrate at all stages of the process, thereby enabling the production of superconducting multilayer composite parts with optimal superconductivity and low resistivity in the normal phase.

[0063] Preferably, in this method, a superconducting film is obtained by growing a first epitaxial layer made of Fe(Se,Te) on a buffer structure, followed by growing a second epitaxial layer made of Fe(Se,Te) on the first epitaxial layer. Attached Figure Description

[0064] The present invention will now be described with reference to the accompanying drawings, which are provided as examples only and are not intended to be limiting. In the drawings: Figure 1A A schematic diagram of a superconducting multilayered composite material part according to the present invention is shown (not drawn to scale). Figure 1BA schematic diagram (not drawn to scale) of a preferred embodiment of a superconducting multilayered composite material part according to the present invention is shown. Figure 2A The XRD spectrum of a Fe(Se,Te) sample deposited at 250 °C on a foil made of TiN / NiW is shown. Figure 2B The ω-scan diagrams of the (001) peak of Fe(Se,Te), the (002) peak of TiN, and the (002) peak of NiW are shown. Figure 3 A graph of the resistivity R(T) of a sample made of Fe(Se,Te) deposited on TiN / NiW at 250 °C as a function of temperature is shown. An enlarged view of the superconducting transition region is shown in the inset. Figure 4 The graph shows the resistivity versus temperature curves of a superconducting multilayered composite material Fe(Se,Te) / TiN / NiW (star-shaped), a conductive substrate (disc), and a conductive substrate (rhomboid) coated with a conductive non-oxide film made of TiN. For comparison, the overall resistivity of the layered material Fe(Se,Te) / CeO2 / NiW (black) is also shown on the right side of the graph. Detailed Implementation

[0065] Referring to the attached figure, the superconducting multilayered composite material component (hereinafter referred to as "superconducting material component") is marked as 10.

[0066] The superconducting multilayer composite material component 10 includes: a conductive substrate 1; an electrically conductive buffer structure 2, which is composed of one or more non-oxide films made of metal nitrides; and a superconducting film 3, which is composed of Fe(Se,Te).

[0067] The buffer structure 2 is usually sandwiched between the conductive substrate 1 and the superconducting membrane 3.

[0068] The metal nitride is selected from the following: TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN and / or combinations thereof.

[0069] exist Figure 2A , Figure 2B , Figure 3 , Figure 4 In a preferred exemplary embodiment of the present invention, the metal nitride is TiN.

[0070] It is worth noting that in the embodiments described herein, TiN represents a preferred metal nitride because it excludes oxides and thus prevents the formation of non-conductive oxides at the interface with the conductive substrate 1. TiN can have a cubic crystal structure that is particularly compatible with the conductive substrate 1 during all stages of manufacturing the multilayer layered composite part 10, for example, with the conductive substrate 1 made of NiW and the superconducting film 3 in Fe(Se,Te).

[0071] Here, for reference Figure 1A In the illustrated embodiment, the structure of the superconducting material component 10 is very simplified. The superconducting material component 10 includes an electrically conductive buffer structure 2 located between the substrate 1 and the superconducting film 3. This electrically conductive buffer structure is composed of a single-layer non-oxide film. When the superconducting film 3 is in the normal phase, the buffer structure 2 allows current to be effectively transferred from the superconducting film 3 to the conductive substrate 1. This efficient current transfer improves the electrical stability of the superconducting material component 10, thereby improving its thermal stability.

[0072] Normal phases are dissipative, and temperature increases may cause serious damage to ordinary superconducting material components. However, according to the present invention, the superconducting material component 10 exhibits a low overall resistivity in the normal phase through the good thermal connection between the buffer structure 2 and the substrate 3, thereby improving thermal and electrical stability.

[0073] The conductive substrate 1 is made of a metal with a cubic texture, which is particularly, but not limited to, selected from the following metals: Ni, Cu, W, Al, Ag, Fe, V and / or alloys thereof.

[0074] In this embodiment, the conductive substrate 1 is composed of Ni and W, wherein the atomic percentage of W is 4% to 10%, preferably equal to 5%; the nominal composition of the superconducting film is Fe(Se). (1-x) ,Te x ), preferably Fe(Se) 0.5 ,Te 0.5 Therefore, the iron-based superconducting film 3 includes 50 atomic% Se and 50 atomic% Te based on the total number of Se and Te atoms.

[0075] refer to Figure 1B The implementation method, in addition to referring to Figure 1A In addition to the described structure, the multilayer composite material component 10 also includes a protective membrane 4 arranged adjacent to the superconducting membrane 3 and a stabilizing membrane 5 disposed on the protective membrane 4.

[0076] The protective film 4 is made of a material selected from the following: Ag, Al, Cu, Fe, nitrogen-containing compounds (such as TiN) and / or alloys or combinations thereof.

[0077] It should be understood that once the foil-shaped superconducting material component 10 is obtained, it can be processed to make wires or strips, thereby making it possible to implement cables.

[0078] Advantageously, this type of cable can be used in applications with high magnetic fields and low operating temperatures, such as large particle accelerators and nuclear magnetic resonance (NMR).

[0079] To prepare the superconducting multilayer composite material 10, a conductive substrate 1 is required, an electrically conductive buffer structure 2 consisting of one or more non-oxide films is grown on the conductive substrate 1, and finally a superconducting film 3 made of Fe (Se, Te) is grown on the buffer structure 2.

[0080] In the preferred embodiment shown in the figure, the buffer structure consists of only one non-oxide film, which is made of a metal nitride, preferably TiN.

[0081] According to some embodiments of the present invention, the superconducting film 3 is obtained by the following steps: growing a first epitaxial layer of the superconducting film 3 made of Fe(Se,Te) on the buffer structure 2, and then growing a second epitaxial layer of the superconducting film 3 made of Fe(Se,Te) on the first epitaxial layer.

[0082] According to the present invention, an example of a preferred method for manufacturing a multilayered composite material part 10 includes using pulsed laser deposition (PLD) technology to prepare an Fe(Se,Te) superconducting film 3, which has conditions compatible with the presence of a TiN film; therefore, it is preferred to use the film of the material part as a monolayer film in a buffer structure 2 between the superconducting film 3 and the conductive substrate 1, the monolayer film being made of a metal nitride.

[0083] According to this embodiment, the conductive substrate 1 is a metal alloy having a nickel-based and / or copper-based cubic texture. Under typical conditions for depositing the iron-based superconducting film 1, TiN acts to block metal diffusion in the substrate.

[0084] Finally, after the entire fabrication process of the superconducting material 10, the TiN film maintained its conductivity and remained connected to the substrate 1. In particular, the superconducting material 10, Fe(Se,Te) / TiN / Ni-W, yielded a sample with optimal superconducting performance and exhibited a low resistivity in the normal phase; the resistivity of this superconducting material 10 in the normal phase was only 1 / 50th of that of the most promising Fe-based superconducting film structures to date. Figure 4 ).

[0085] The advantage of the superconducting material component 10 is that the conductive substrate 1 can provide the electrical and thermal stability required by the superconducting material component 10, either partially or entirely.

[0086] Referring to the method shown above and the preferred embodiment of the superconducting material 10, it can be seen that the conductive substrate 1 is a commercially available nickel- and tungsten-based metal foil, Ni-5at.%W (NiW), having a cubic texture

[21] . The film is deposited using pulsed laser deposition (PLD) technology by the following steps: preferably using the fourth harmonic (266 nm) of an Nd:YAG Q-switched solid-state laser or wavelengths of 355 nm, 532 nm, and 1064 nm, with a repetition frequency preferably of 3 Hz or between 10 Hz and 20 Hz, and an energy density of 1 J / cm² to 2 J / cm² applied to the target. In other embodiments, the film can also be deposited using an excimer laser operating under ultraviolet light, such as KrF (248 nm) or XeCl (308 nm).

[0087] According to alternative implementation schemes, sputtering technology can be used to deposit films.

[0088] Example of method implementation The distance between the target and the conductive substrate 1 was arranged to be approximately 40 mm. The TiN layer was grown in the deposition chamber. The substrate pressure reached 0.2 × 10⁻⁶ mm. -6 mTorr to 2.2×10 -6 After mTorr, the chamber is filled with N2 gas until the pressure reaches between 20 mTorr and 0.1 mTorr, and the temperature is between 600°C and 400°C, starting with a commercially available target [32, 40] at the first stoichiometric ratio. A superconducting film 3 made of Fe(Se,Te) is deposited under vacuum conditions at a pressure between 3 × 10⁻⁶ mTorr and 10⁻⁶ mTorr. -7 mbar to 3×10 - 6 Between mbar. The nominal composition of the second target material prepared in the laboratory is FeSe. 0.5 Te 0.5

[41] . The growth rate of the superconducting film 3 made of Fe(Se,Te) was approximately 0.06 nm / s. X-ray diffraction was used to analyze the film. Angular divergence measurements were used to analyze structural properties. The quality of out-of-plane crystal orientation was assessed by full width at half maximum (FWHM) during ω-scanning. The temperature dependence of resistance R(T) was measured using four-terminal sensing.

[0089] A buffer structure 2 is coated on a NiW conductive substrate, which is composed of a non-oxide film 2 made of TiN grown at 500 °C

[35] . The film is epitaxial, and the average full width at half maximum (FWHM) of the ω-scan of the TiN (002) and NiW (002) peaks are 5.2° and 6.9°, respectively. Figure 2B ).

[0090] A two-step method was used to deposit a superconducting film 3 made of Fe(Se,Te)

[42] . First, a superconducting epitaxial layer made of Fe(Se,Te) was deposited on a buffer structure 2 made of TiN, and then a second superconducting epitaxial layer was deposited on the first layer, with the deposition temperature decreasing between the first and second steps.

[0091] Due to the homoepitaxial mechanism, this method enables control over both the crystal structure and stoichiometric composition of the superconducting film 3 made of Fe(Se,Te), and ensures excellent superconducting performance [42, 26, 37, 43].

[0092] In fact, the lattice incompatibility between TiN and Fe(Se,Te) is 27% (on the diagonal of the lattice parameters) or 11% (cube to cube).

[0093] Despite this high degree of incompatibility, the superconducting multilayer composite material 10 still exhibits good superconducting properties and low resistivity of the normal phase. This is thanks to the two-step deposition method, which enables the first epitaxial layer to form a good crystal structure and provides superconducting properties between the buffer layer 2 and the superconducting film 3 through the second epitaxial layer. Figure 2A The XRD pattern of a superconducting composite material 10 is shown. This superconducting composite material 10 was obtained by depositing TiN on a conductive substrate made of NiW at 500°C, and depositing a film made of Fe(Se,Te) on the surface of a film of the same material deposited at 400°C. The entire structure is oriented along the c-axis perpendicular to the conductive substrate, and only the (00l) diffraction peak of the existing film is present in the figure.

[0094] Figure 2B The previously defined ω-scan “rocking curves” (RC) of a conductive substrate 1 made of NiW, a conductive non-oxide film made of TiN, and a superconducting film made of Fe(Se,Te) are shown, where a full width at half maximum (FWHM) value of 3.2° indicates excellent epitaxial growth of the film made of Fe(Se,Te).

[0095] Figure 3 The resistivity of a sample made of Fe(Se,Te) / TiN / NiW as a function of temperature is shown. Figure 2A and Figure 2B The sample in the illustration is the same as the one in the original. The illustration shows the details of the superconducting transition.

[0096] In order to evaluate the electrical connection between the superconducting film 3 and the conductive substrate 1, the overall resistivity of the sample was measured using the van der Bauer method to determine the resistivity from the resistance measurement value using the known thickness of the superconducting material part 10

[44] .

[0097] Figure 4 The resistivity curves of conductive substrate 1 made of NiW, conductive non-oxide film 2 made of TiN, and superconducting film 3 made of Fe(Se,Te) / TiN / NiW are shown as a function of temperature.

[0098] In contrast, measurements of samples grown on the same type of substrate showed that a cerium-based oxide film, Fe(Se,Te) / CeO2 / NiW, was deposited on it.

[0099] The latter sample is characterized by a bell-shaped resistance curve in the normal phase. This bell-shaped curve is characteristic of the material Fe(Se,Te)

[45] , thus confirming that cerium oxide isolates the superconducting film from the substrate.

[0100] Considering the TiN film instead, the resistivity of the TiN-only sample and the sample containing the superconducting film 3 is comparable within the experimental error range and similar to the resistivity of the conductive substrate 1. This indicates that current is effectively transferred from the superconducting film 3 to the substrate through the conductive non-oxide film 2.

[0101] This resistivity is only 1 / 50th that of the cerium oxide film, indicating that the TiN film ensures current transmission from the superconducting film 3 to the conductive substrate 1. These results demonstrate that the TiN film provides optimal electrical connection between the superconducting film 3 and the metal substrate 1.

[0102] For the aforementioned multilayered composite material parts and related methods for preparing multilayered composite material parts, those skilled in the art may introduce several additional modifications and variations to meet additional and incidental needs, but all such modifications and variations fall within the scope of protection defined by the appended claims.

[0103] References [1] Kamihara Y, et al. 2008 J. Am. Chem. Soc., 130, 11, 3296–3297 [2] Hsu FC, et al., 2008, Proc. Natl. Acad. Sci. USA, 105 (38) 14262-14264 [3] Fang MH, 2008, Phys. Rev. B 78, 224503 [4] Yeh KW, et al., 2008 EPL 84 37002 [5] Kumary TG, et al. 2009 Supercond. Sci. Technol. 22 095018 [6]Bellingeri E, et al. 2009 Supercond. Sci. Technol. 22 105007 [7] Si W, et al. 2009 Applied Physics Letters 95, 052504 [8] Wu MK, et al. 2009 Physica C 469 340–349 [9] Bellingeri E, et al 2010 Appl. Phys. Lett. 96 102512

[10] Bellingeri E, et al 2012 Supercond. Sci. Technol. 25 084022

[11] Taen T, et al. 2010 Physica C 470 S391–S393

[12] Si W, et al. 2011 Applied Physics Letters 98, 262509

[13] Si W, et al. 2013 Nat. Commun. 4:1347

[14] Uglietti D, 2019 Supercond. Sci.Technol. 32 053001

[15] Ozaki T, et al. 2011 Supercond. Sci. Technol.24 105002

[16] Pellecchi I, et al. 2015 Supercond. Sci. Technol. 28 114005

[17] Palombo M, et al. 2015 Journal of Applied Physics 117 213903

[18] Sylva G, et al. 2019 IEEE Trans. Appl. Supercond. 32 084006

[19] Xu Z, 2017 Supercond. Sci. Technol. 30 035003

[20] Goyal A, et al. Structures having enhanced biaxial texture andmethod of fabricating same, US5741377, Lockheed Martin Energy Systems Inc,1995-04-10.

[21] Huhne R, et al. 2010 Supercond. Sci. Technol. 23 034015

[22] IiJima Y, et al., Method of making polycrystalline thin film andsuperconducting oxide body, US5650378A, Fujikura Ltd, 1995-08-03. or Jia Q.,et al. Buffer layers on metal alloy substrates for superconducting tapes,US6756139B2, Los Alamos National Security LLC, 2002-03-28, ecc

[23] Li Q., et al. Iron based superconducting structures and methodsfor making the same, US20130196856A1, Brookhaven Science Associates LLC,2011-08-02.

[24] Xu Z,. et al. Preparation method of iron base compoundsuperconducting thin film, CN105839056A e CN105839056B B, INSTITUTE OFELECTRICAL ENGINEERING - CHINESE ACADEMY OF SCIENCES, 2016-08-10

[25] Liu L, et al. Fe (Se, Te) superconducting thick film andpreparation method and application thereof, CN114318242A, Shanghai JiaotongUniversity, 2022-04-12

[26] Ye J, et al. 2022 J. Appl. Phys. 132, 183910

[27] Sylva G, et al. 2020 Supercond. Sci. Technol. 33 114002

[28] Holleis S, et al. 2022 Supercond. Sci. Technol. 35 074001

[29] Aytung T, et al. 2001 J. Mater. Res. Vol. 16, 2661

[30] Aytung T, et al. 2001 Applied Physics Letters 79, 2205

[31] Aytung T, et al. 2003 Applied Physics Letters 83, 3963

[32] Cantoni C, et al. 2004 Supercond. Sci. Technol. 17 S341-S344

[33] Cantoni C, et al. 2005 IEEE Trans. Appl. Supercond. 15-2 2981

[34] Xia Y, et al. 2014 J. Supercond. Nov. Magn. 27:871–875

[35] Mancini A, et al. 2015 IEEE Trans. Appl. Supercond. 25-3 6604605

[36] Wu KH, et al 2001 Physica C 363 119–129

[37] Thomas AA, al. 2021 Supercond. Ski. Technol. 34 115013

[38] Mancini A, et al. 2011 IEEE Trans. Appl. Supercond. 21-3 2891

[39] Varesi E, et al. 2003 Supercond. Ski. Technol. 16 498–505

[40] Supplier Ceraco Ceramic Coating GmbH

[41] Masi A, et al. 2020 J. Phys.: Conf. Ser. 1559 012051

[42] Molatta S, et al. 2015 Sci. Rep. 5 , 16334

[43] Piperno L, et al. 2023 Sci. Rep. 13 1–11

[44] van der Pauw LJ 1958 Philips Technical Review 20 220–224

[45] Masi A, et al. 2020 Supercond. Ski. Technol. 33 084007。

Claims

1. A superconducting multilayered composite material component (10), the superconducting multilayered composite material component comprising: -Conductive substrate (1); - Electrically conductive buffer structure (2), the electrically conductive buffer structure is composed of one or more non-oxide films, the non-oxide films being made of metal nitrides; - Superconducting film (3), the superconducting film is composed of Fe (Se, Te), wherein Fe (Se, Te) is a compound containing Fe atoms and at least a chalcogenide anion, the chalcogenide anion being composed of Se atoms and Te atoms in a variable proportion; The buffer structure (2) is sandwiched between the conductive substrate (1) and the superconducting film (3).

2. The multilayered composite material part (10) according to claim 1, wherein, The superconducting film (3) includes: a first epitaxial layer grown on the buffer structure (2), the first epitaxial layer being made of Fe(Se,Te); and a second epitaxial layer grown on the first epitaxial layer, the second epitaxial layer being made of Fe(Se,Te).

3. The multilayered composite material part (10) according to claim 1 or 2, wherein, The metal nitride is selected from the following: TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN and / or combinations thereof.

4. The multilayered composite material part (10) according to claim 1 or 2, wherein, The metal nitride is composed of TiN.

5. The multilayered composite material part (10) according to any one of the preceding claims, wherein, The conductive substrate (1) is a metal selected from the following: Ni, Cu, W, Al, Ag, Fe, V and / or alloys thereof.

6. The multilayered composite material part (10) according to any one of the preceding claims, wherein, The conductive substrate (1) is a metal foil with a cubic texture.

7. The multilayered composite material part (10) according to any one of the preceding claims, wherein, The conductive substrate (1) is composed of Ni and W, wherein the atomic percentage of W is between 4% and 10%.

8. The multilayered composite material part (10) according to any one of the preceding claims, wherein, The superconducting film (3) is composed of FeSe. (1-x) Te x x is between 0 and 1.

9. The multilayered composite material part (10) according to any one of the preceding claims, wherein the multilayered composite material part further comprises: A protective film (4) adjacent to the superconducting film (3); And a stabilizing film (5) disposed on the protective film (4).

10. The multilayered composite material part (10) according to claim 9, wherein, The protective film (4) is made of a material selected from the following: Ag, Al, Cu, Fe, nitrogen-containing compounds and / or alloys or combinations thereof, for example, the nitrogen-containing compound is TiN.

11. The multilayered composite material part (10) according to claim 9 or 10, wherein, The stabilizing film (5) is made of a material selected from the following: Cu, Al and / or alloys or combinations thereof.

12. The multilayer composite material part (10) according to any one of the preceding claims, wherein the multilayer composite material part is used in the form of foil, strip, wire or cable.

13. A method for preparing a multilayered composite material part (10), the method comprising the following steps: • Set up a conductive substrate (1); • An electrically conductive buffer structure (2) is grown on the conductive substrate (1), the electrically conductive buffer structure being composed of one or more non-oxide films made of metal nitrides; • A superconducting film (3) is grown on the buffer structure (2), the superconducting film being made of Fe(Se,Te).

14. The method according to claim 13, wherein, The metal nitride is selected from the following: TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN and / or combinations thereof.

15. The method according to claim 13, wherein, The metal nitride is composed of TiN.

16. The method according to claim 13, wherein, The conductive substrate (1) has a cubic texture and is composed of Ni-W, wherein, preferably, the atomic percentage of W is between 4% and 10%.

17. The method according to one or more of claims 13 to 16, wherein, The superconducting film (3) is obtained by growing a first epitaxial layer made of Fe (Se, Te) on the buffer structure (2), and then growing a second epitaxial layer made of Fe (Se, Te) on the first epitaxial layer, wherein the first epitaxial layer is not necessarily superconducting.

18. The method according to claim 17, wherein, The first epitaxial layer of the superconducting film (3) is grown at a temperature between 300°C and 450°C, and the second epitaxial layer of the superconducting film (3) is grown at a temperature between 200°C and 300°C.

19. The method according to one or more of claims 13 to 18, wherein, Pulsed laser deposition (PLD) technology was used to grow the buffer structure (2) and the superconducting film (3).

20. The method for preparing a multilayered composite material part (10) according to one or more of claims 13 to 19, the method comprising the steps of: • A conductive substrate is provided on the heating element (1); • Set up a sedimentation chamber; • Set up a first target material made of TiN; • Adjust the pressure in the deposition chamber to 3 × 10 -5 Pa to 3×10 -4 Between Pa; • Heat the substrate to a temperature between 400°C and 600°C; • The pressure in the deposition chamber is adjusted to between 0.01 Pa and 2.6 Pa by introducing N2; • A buffer structure (2) is grown on the conductive substrate (1) using PLD technology. The buffer structure is composed of a non-oxide film made of TiN. • Remove the first target material; • A second target material is provided, which is made of Fe(Se,Te); • Adjust the pressure in the deposition chamber to 3 × 10 -5 Pa to 3×10 -4 Between Pa; • Adjust the temperature to between 300°C and 450°C; • The first epitaxial layer of the superconducting film (3) is grown on the buffer structure (2) using PLD technology, the first epitaxial layer being made of Fe(Se,Te); • Adjust the temperature to between 200°C and 300°C; and • A second epitaxial layer of the superconducting film (3) is grown on the first epitaxial layer of the superconducting film (3) using PLD technology, the second epitaxial layer being made of Fe(Se,Te).

21. The method according to claim 20, wherein, For the PLD technology, the fourth harmonic (266 nm) of an Nd:YAG Q-switched solid-state laser with a repetition frequency of 3 Hz and an energy density of 1 J / cm² to 2 J / cm² applied to the second target is used.

22. The method according to claim 20, wherein, The distance between the first target and the conductive substrate (1) is between 30 mm and 50 mm.

23. The method of claim 20, wherein, The distance between the second target and the buffer structure (2) is between 30 mm and 50 mm.

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