Iron-manganese-based non-equivalent double perovskite epitaxial thin film and preparation process and application thereof

Abstract

The invention belongs to the field of semiconductor materials, and discloses an iron-manganese-based non-equivalent double perovskite epitaxial thin film and a preparation process and application thereof. The molecular formula of the ferro-manganese-based non-equivalent double perovskite epitaxial thin film is Bi < 2-2x > Me < 2x > FeMnO6, the value range of x is 0.01-0.5, and Me is Ca, Sr, Pb and other metal elements of a second main group and a fourth main group. The specific process is as follows: through a magnetron sputtering method, using a secondarily sintered iron-manganese-based ceramic target material, and simultaneously regulating and controlling the oxygen / argon ratio and the deposition temperature, preparing various ordered iron-manganese-based non-equivalent multifunctional double-perovskite epitaxial films with tetragonal structures. According to the invention, the valence states of Fe and Mn elements in the thin film are precisely regulated and controlled by adopting non-equivalent design, and the ordered double perovskite thin film applied to the multifunctional semiconductor fields such as electric storage, magnetic storage and optical storage can be prepared through different substitution contents.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor materials and discloses an iron-manganese-based non-equivalent double perovskite epitaxial film and a preparation process and application thereof. Technical Background

[0002] At present, bismuth iron manganese oxide double perovskite film has a variety of different phase structures, such as tetragonal phase structure, orthorhombic phase structure and layered structure, which supports its excellent physical properties. In addition, bismuth iron manganese oxide double perovskite film has a thermal conductivity of about 50μC / cm 2 The remnant polarization intensity, saturation magnetization intensity of about 15emu / cc and ultra-narrow band gap of about 1.2-1.5eV can be used to design and prepare multifunctional semiconductor devices such as Hall devices and photoelectric coupling devices.

[0003] However, after years of research, researchers have found that the multifunctionality of bismuth ferromanganate double perovskite films is highly dependent on their phase structure, such as ferroelectricity depends on the tetragonal phase, and higher saturation magnetization only exists in the narrow band gap of layered structures and orthorhombic structures. Although a single performance in a certain structure is significantly advantageous, its coupling has not yet been demonstrated. There is an urgent need to provide a method to couple the multifunctionality of bismuth ferromanganate double perovskite films in the same film to solve the problem of multifunctional application in single bismuth ferromanganate-based double perovskite film devices. Summary of the invention

[0004] The invention discloses an iron-manganese-based non-equivalent double perovskite epitaxial film and a preparation process and application thereof, so as to solve any of the above and other potential problems of the prior art.

[0005] To achieve the above object, the technical solution of the present invention is: an iron-manganese-based non-equivalent double perovskite epitaxial film, the iron-manganese-based non-equivalent double perovskite epitaxial film is grown on a single crystal substrate, and the chemical formula of the iron-manganese-based non-equivalent double perovskite epitaxial film is: Bi 2-2x Me 2x FeMnO 6 , where the value range of x is: 0.01-0.5

[0006] Furthermore, the iron-manganese-based non-equivalent double perovskite epitaxial film has a tetragonal structure and a space group of P4mm.

[0007] Furthermore, the single crystal substrate is SrTiO 3 、Nb-SrTiO 3 ,La 0.7 Sr 0.3 MnO 3 / SrTiO 3 or SrRuO 3 / SrTiO 3.

[0008] Furthermore, the Me is one of the metal elements of the second and fourth main groups.

[0009] Another object of the present invention is to provide a method for preparing the above-mentioned iron-manganese-based non-equivalent double perovskite epitaxial film by magnetron sputtering, characterized in that the process includes three steps:

[0010] S1) Select a corresponding single crystal substrate, clean it, blow it dry and set it aside for use;

[0011] S2) preparing an iron-manganese based ceramic target;

[0012] S3) placing the single crystal substrate processed by S1) and the iron-manganese-based ceramic target obtained by S2) in corresponding platforms, starting the heating platform to heat the substrate to a set temperature, and using radio frequency magnetron sputtering preparation technology to deposit a thin film on the iron-manganese-based ceramic target to obtain an iron-manganese-based multifunctional double perovskite epitaxial film.

[0013] Further, the specific steps of S2) are:

[0014] S2.1) Mix Bi with a certain molar ratio 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and MeCO 3 The powder was placed in an agate mortar, and the dispersant was added several times and ground for 1-2 hours to obtain a uniform mixed powder, which was then dried in an oven for later use;

[0015] S2.2) sintering the mixed powder dried in S2.1) to obtain a primary sintered powder;

[0016] S2.3) The primary sintered powder in S2.2) is placed in an agate mortar again, a binder and a dispersant are added, and the mixture is ground for 2-4 hours to obtain a uniform primary sintered mixed powder, which is then dried naturally for later use;

[0017] S2.4) pressing the primary sintered mixed powder in S2.3) under certain conditions to obtain a pressed target;

[0018] S2.5) Sintering the pressed target material in S2.4) under certain conditions to obtain an iron-manganese based ceramic target material.

[0019] Furthermore, Bi in S2.1) 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and MeCO3 The molar ratio between the powders is: 2.3-2.3x:1:1:4x, wherein the value range of x is: 0.01-0.5;

[0020] The primary sintering conditions in S2.2) are: heating to 500°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, then heating to 750°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, and then cooling to room temperature with the furnace;

[0021] The pressing conditions in S2.4) are: pressing at a pressure of 9-11 MPa for 4.9-5.1 min, and then pressing at a pressure of 29-31 MPa for 9.9-10.1 min;

[0022] The target sintering conditions in S2.5) are as follows: the temperature is raised to 500°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, then the temperature is raised to 830°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, and then the temperature is lowered to room temperature with the furnace.

[0023] Further, the specific process of the radio frequency magnetron sputtering preparation technology in S3) is:

[0024] The vacuum degree is less than 1×10 -6 Torr, single crystal substrate temperature is 649-651℃, Ar / O 2 The flow ratio is 3:7, the total gas flow is 9.9-10.1sccm, the working gas pressure is 0.39-0.41Pa, the RF power is 89-91W for deposition for 49.5-50.5min, then 29-31W for deposition for 9.5-10.5min, and then annealing in an oxygen atmosphere of 100-110Pa for 19-21min.

[0025] Furthermore, the residual polarization intensity of the iron-manganese-based non-equivalent double perovskite epitaxial film obtained by the process is not less than 15 μC / cm 2 , saturation magnetization not less than 25emu / cc and open circuit voltage not less than 350μA / cm 2 .

[0026] The iron-manganese-based double perovskite epitaxial film prepared by the above process is used in the semiconductor fields of ferroelectricity, ferromagnetism, photovoltaics and photoelectric coupling.

[0027] Furthermore, the non-equivalence refers to a method of using a divalent or tetravalent metal element to replace the A position and then inducing the valence state of the B position element to change to tetravalent or divalent, wherein the so-called A position and B position refer to two atomic positions in the perovskite structure.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects:

[0029] 1. The present invention provides a preparation process of an iron-manganese-based non-equivalent double perovskite epitaxial film based on a magnetron sputtering method.

[0030] 2. The present invention provides a method for regulating the multifunctional coupling of an iron-manganese-based double perovskite epitaxial film. When x=0.1, the multifunctional coupling of the iron-manganese-based double perovskite epitaxial film is the highest, and has the most multifunctional types.

[0031] 3. The present invention can precisely control the valence state of Fe and Mn elements in the film, thereby stabilizing the multifunctional tetragonal phase of the film, and then controlling the properties of the film, such as ferroelectricity, ferromagnetism, photovoltaics and their multifunctional coupling. It promotes the development of such films in the multifunctional field of ferroelectric semiconductors and expands the application range of devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the regulation and structure of the iron-manganese-based non-equivalent double perovskite epitaxial film described in the present invention.

[0033] Figure 2 The iron-manganese-based Bi 2-2x Sr 2x FeMnO 6 Non-equivalent double perovskite epitaxial thin films on SrTiO 3 XRD patterns and out-of-plane lattice constants of the deposited substrate vary with x, where x is 0.1, 0.2, 0.3 and 0.4.

[0034] Figure 3 The iron-manganese-based Bi 1.8 Sr 0.2 FeMnO 6 Photovoltaic curves, hysteresis loops, and magnetic hysteresis loops of non-equivalent double perovskite epitaxial films.

[0035] Figure 4 The iron-manganese-based Bi 2-2x Pb 2x FeMnO 6 Non-equivalent double perovskite epitaxial thin films on SrTiO 3 XRD patterns and out-of-plane lattice constants of the deposited substrate vary with x, where x is 0.1, 0.2 and 0.3.

[0036] Figure 5 The iron-manganese-based Bi 1.8 Pb 0.2 FeMnO 6 Photovoltaic curves and hysteresis loops of non-equivalent double perovskite epitaxial films.

[0037] Figure 6 The iron-manganese-based Bi 2-2x Pb 2x FeMnO 6 XPS graph of non-equivalent double perovskite epitaxial film, where the values ​​of x are 0.1, 0.2 and 0.3. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below in conjunction with the drawings and specific embodiments.

[0039] like Figure 1 As shown, the present invention provides an iron-manganese-based non-equivalent double perovskite epitaxial film, the structure of the epitaxial film includes a substrate and an iron-manganese-based non-equivalent double perovskite epitaxial film epitaxially grown on the substrate, the substrate is a single crystal substrate, the crystal structure of the iron-manganese-based non-equivalent double perovskite epitaxial film is a tetragonal phase structure, and the space group is P4mm.

[0040] The chemical formula of the iron-manganese-based non-equivalent double perovskite epitaxial film is Bi 2-2x Me 2x FeMnO 6 , where the value range of x is: 0.01-0.5.

[0041] The single crystal substrate is SrTiO 3 、Nb-SrTiO 3 ,La 0.7 Sr 0.3 MnO 3 / SrTiO 3 or SrRuO 3 / SrTiO 3 One of them.

[0042] The single crystal substrate has a crystal plane orientation of (001), (011) or (111), and a specific size of 3×5×0.3 mm 3 ,5×5×0.3mm 3 or 10×10×0.3mm 3 .

[0043] The Me is one of the second and fourth main group metal elements such as Ca, Sr, Pb, etc.

[0044] Another object of the present invention is to provide a process for preparing the above-mentioned iron-manganese-based non-equivalent double perovskite epitaxial film by magnetron sputtering, the process comprising the following steps:

[0045] S1) Select a corresponding single crystal substrate, clean it, blow it dry and set it aside for use;

[0046] S2) preparing an iron-manganese based ceramic target;

[0047] S3) placing the single crystal substrate processed by S1) and the iron-manganese-based ceramic target obtained by S2) in corresponding platforms, starting the heating platform to heat the substrate to a set temperature, and using radio frequency magnetron sputtering preparation technology to deposit a thin film on the iron-manganese-based ceramic target to obtain an iron-manganese-based multifunctional double perovskite epitaxial film.

[0048] The single crystal substrate is selected, and then the substrate surface needs to be cleaned with acetone, anhydrous ethanol and deionized water in sequence, and then high-purity N 2 Air dry.

[0049] The preparation process of the iron-manganese based ceramic target in S2) is specifically as follows:

[0050] S2.1) Mix Bi with a certain molar ratio 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and MeCO 3 The powder was placed in an agate mortar, and the dispersant was added several times and ground for 1-2 hours to obtain a uniform mixed powder, which was then dried in an oven for later use;

[0051] S2.2) sintering the mixed powder dried in S2.1) to obtain a primary sintered powder;

[0052] S2.3) The primary sintered powder in S2.2) is placed in an agate mortar again, a binder and a dispersant are added, and the mixture is ground for 2-4 hours to obtain a uniform primary sintered mixed powder, which is then dried naturally for later use;

[0053] S2.4) pressing the primary sintered mixed powder in S2.3) under certain conditions to obtain a pressed target material for standby use;

[0054] S2.5) Sintering the pressed target material in S2.4) under certain conditions to obtain an iron-manganese based ceramic target material.

[0055] Bi in S2.1) 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and MeCO 3 The molar ratio of the powders is: 2.3-2.3x:1:1:4x, wherein the value range of x is: 0.01-0.5.

[0056] The primary sintering conditions in S2.2) are: heating to 500°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, then heating to 750°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, and then cooling to room temperature with the furnace;

[0057] The pressing conditions in S2.4) are: pressing at a pressure of 9-11 MPa for 4.9-5.1 min, and then pressing at a pressure of 29-31 MPa for 9.9-10.1 min;

[0058] The target sintering conditions in S2.5) are as follows: the temperature is raised to 500°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, then the temperature is raised to 830°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, and then the temperature is lowered to room temperature with the furnace.

[0059] In the above S2.1) and S2.3), anhydrous ethanol with a concentration of 99.5% is used as a dispersant.

[0060] In said S2.3), an aqueous solution of polyvinyl alcohol is used as a binder; the concentration of the binder is 0.1 mg / L; and the ratio of the binder to the mass of the mixed powder before the primary sintering is 0.2 ml / 1 g.

[0061] In the above S2.4), the target material after pressing is round, with a diameter of 1-3 inches and a thickness of about 1.9-2.1 mm.

[0062] In S3), the specific process of the radio frequency magnetron sputtering preparation technology is:

[0063] The vacuum degree is less than 1×10 -6 Torr, single crystal substrate temperature is 649-651℃, Ar / O 2 The flow ratio is 3:7, the total gas flow is 9.9-10.1sccm, the working gas pressure is 0.39-0.41Pa, the RF power is 89-91W for deposition for 49.5-50.5min, then 29-31W for deposition for 9.5-10.5min, and then annealing in an oxygen atmosphere of 100-110Pa for 19-21min.

[0064] The obtained Fe-Mn-based non-equivalent double perovskite epitaxial film has multifunctionality, such as up to 15 μC / cm 2 The remanent polarization intensity, saturation magnetization intensity of 25emu / cc and 350μA / cm 2 of open circuit voltage.

[0065] The obtained iron-manganese-based double perovskite epitaxial film has a thickness of 40-85 nm.

[0066] During the deposition of the obtained iron-manganese-based double perovskite epitaxial film, the average sputtering rate is about

[0068] The iron-manganese-based double perovskite epitaxial film is deposited in a multiphase state when the substrate temperature is 600-645°C, and is deposited in an amorphous state when the substrate temperature is lower than 600°C.

[0069] For the iron-manganese-based double perovskite epitaxial thin film, when the oxygen / argon ratio is higher or lower than 7:3, the deposited thin film is in a multi-phase state.

[0070] The non-equivalence refers to a method of using a divalent or tetravalent metal element to replace the A position and then inducing the valence state of the B position element to change to a tetravalent or divalent state.

[0071] The A site and B site refer to two atomic positions in the perovskite structure.

[0072] The element valence state change is characterized by photoelectron spectroscopy XPS.

[0073] Embodiment 1:

[0074] Bi with a molar ratio of 2.07:1:1:0.4 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and SrCO 3 After the powders are mixed, anhydrous ethanol is added as a dispersant, and the powders are carefully ground for 1 hour to obtain a uniform mixed powder, which is then dried in an oven; the uniform mixed powder after drying is placed in a cylindrical crucible, and then heated to 500°C at a rate of 10°C / min and kept warm for 1 hour, and then heated to 750°C at a rate of 10°C / min and kept warm for 1 hour, and then cooled to room temperature with the furnace; the mixed powder sintered once is ground again, and polyvinyl alcohol solution is added as a binder and anhydrous ethanol is used as a dispersant. After grinding carefully for 3 hours, a uniform primary sintered mixed powder is obtained, which is naturally dried; the uniform primary sintered mixed powder is placed in a circular mold, and then a pressure of 10MPa is applied to press for 5 minutes, and then a pressure of 30MPa is applied to press for 10 minutes to obtain a circular target; the target is heated to 500°C at a rate of 5°C / min with the furnace and kept warm for 2 hours, and then heated to 830°C at a rate of 5°C / min and kept warm for 2 hours, and then cooled to room temperature with the furnace to obtain Bi 2.07 Sr 0.2 FeMnO 6 Ceramic target: (001) oriented SrTiO 3The single crystal substrate and the ceramic target were placed on the heating platform and RF sputtering platform of the magnetron sputtering instrument respectively, and the background vacuum was reduced to 1×10 - 6 Torr, while maintaining the substrate temperature at 650°C; then Ar and O were introduced into the magnetron sputtering chamber 2 , ensuring Ar / O 2 The flow ratio is 3:7, the gas flow rate is 10sccm, and the working pressure is 0.4Pa; 2.07 Sr 0.2 FeMnO 6 The ceramic target was subjected to 90W RF power for 50 minutes of deposition, and then 60W RF power was applied for 10 minutes of deposition. Then, 100Pa of oxygen was introduced for annealing for 20 minutes to obtain a 67nm thick high-quality Bi 1.8 Sr 0.2 FeMnO 6 Multifunctional double perovskite epitaxial film. Its XRD Figure 2 As shown, there are only diffraction peaks of the film and the substrate, indicating the epitaxial nature of the film; for this film, we obtained photovoltaic curves, hysteresis loops, and magnetic hysteresis loops in the same film, indicating its multifunctionality, such as Figure 3 shown.

[0075] Embodiment 2:

[0076] Bi with a molar ratio of 2.07:1:1:0.4 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and PbCO 3 After the powders are mixed, anhydrous ethanol is added as a dispersant, and the powders are carefully ground for 1 hour to obtain a uniform mixed powder, which is then dried in an oven; the uniform mixed powder after drying is placed in a cylindrical crucible, and then heated to 500°C at a rate of 10°C / min and kept warm for 1 hour, and then heated to 750°C at a rate of 10°C / min and kept warm for 1 hour, and then cooled to room temperature with the furnace; the mixed powder sintered once is ground again, and polyvinyl alcohol solution is added as a binder and anhydrous ethanol is used as a dispersant. After grinding carefully for 3 hours, a uniform primary sintered mixed powder is obtained, which is naturally dried; the uniform primary sintered mixed powder is placed in a circular mold, and then a pressure of 10MPa is applied to press for 5 minutes, and then a pressure of 30MPa is applied to press for 10 minutes to obtain a circular target; the target is heated to 500°C at a rate of 5°C / min with the furnace and kept warm for 2 hours, and then heated to 830°C at a rate of 5°C / min and kept warm for 2 hours, and then cooled to room temperature with the furnace to obtain Bi 2.07 Pb 0.2FeMnO 6 Ceramic target: (001) oriented SrTiO 3 The single crystal substrate and the ceramic target were placed on the heating platform and RF sputtering platform of the magnetron sputtering instrument respectively, and the background vacuum was reduced to 1×10 - 6 Torr, while maintaining the substrate temperature at 650°C; then Ar and O were introduced into the magnetron sputtering chamber 2 , ensuring Ar / O 2 The flow ratio is 3:7, the gas flow rate is 10sccm, and the working pressure is 0.4Pa; 2.07 Pb 0.2 FeMnO 6 The ceramic target was subjected to 90W RF power for 50 minutes of deposition, and then 60W RF power was applied for 10 minutes of deposition. Then, 100Pa of oxygen was introduced for annealing for 20 minutes to obtain a 64nm thick high-quality Bi 1.8 Pb 0.2 FeMnO 6 Multifunctional double perovskite epitaxial film. Its XRD Figure 4 As shown, there are only diffraction peaks of the film and the substrate, indicating the epitaxial nature of the film; for this film, we obtained photovoltaic curves and hysteresis loops in the same film, indicating its multifunctionality, such as Figure 5 XPS shows that the valence of Fe and Mn is related to the Pb content, as shown in Figure 6 shown.

[0077] Embodiment 3:

[0078] Bi with a molar ratio of 1.84:1:1:0.8 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and SrCO 3After the powders are mixed, anhydrous ethanol is added as a dispersant, and the powders are carefully ground for 1 hour to obtain a uniform mixed powder, which is then dried in an oven; the uniform mixed powder after drying is placed in a cylindrical crucible, and then heated to 500°C at a rate of 10°C / min and kept warm for 1 hour, and then heated to 750°C at a rate of 10°C / min and kept warm for 1 hour, and then cooled to room temperature with the furnace; the mixed powder sintered once is ground again, and polyvinyl alcohol solution is added as a binder and anhydrous ethanol is used as a dispersant. After grinding carefully for 3 hours, a uniform primary sintered mixed powder is obtained, which is naturally dried; the uniform primary sintered mixed powder is placed in a circular mold, and then a pressure of 10MPa is applied to press for 5 minutes, and then a pressure of 30MPa is applied to press for 10 minutes to obtain a circular target; the target is heated to 500°C at a rate of 5°C / min with the furnace and kept warm for 2 hours, and then heated to 830°C at a rate of 5°C / min and kept warm for 2 hours, and then cooled to room temperature with the furnace to obtain Bi 1.84 Sr 0.4 FeMnO 6 Ceramic target: (001) oriented SrTiO 3 The single crystal substrate and the ceramic target were placed on the heating platform and RF sputtering platform of the magnetron sputtering instrument respectively, and the background vacuum was reduced to 1×10 - 6 Torr, while maintaining the substrate temperature at 650°C; then Ar and O were introduced into the magnetron sputtering chamber 2 , ensuring Ar / O 2 The flow ratio is 3:7, the gas flow rate is 10sccm, and the working pressure is 0.4Pa; 1.6 Sr 0.4 FeMnO 6 The ceramic target was subjected to 90W RF power for 50 minutes of deposition, and then 60W RF power was applied for 10 minutes of deposition. Then, 100Pa of oxygen was introduced for annealing for 20 minutes to obtain a 70nm thick high-quality Bi 1.84 Sr 0.4 FeMnO 6 Multifunctional double perovskite epitaxial film. Its XRD Figure 2 As shown, there are only diffraction peaks of the film and the substrate, indicating the epitaxial nature of the film.

[0079] Embodiment 4:

[0080] Bi with a molar ratio of 1.84:1:1:0.8 2 O 3 , Fe 2 O 3 , Mn 2 O 3 and PbCO 3After the powders are mixed, anhydrous ethanol is added as a dispersant, and the powders are carefully ground for 1 hour to obtain a uniform mixed powder, which is then dried in an oven; the uniform mixed powder after drying is placed in a cylindrical crucible, and then heated to 500°C at a rate of 10°C / min and kept warm for 1 hour, and then heated to 750°C at a rate of 10°C / min and kept warm for 1 hour, and then cooled to room temperature with the furnace; the mixed powder sintered once is ground again, and polyvinyl alcohol solution is added as a binder and anhydrous ethanol is used as a dispersant. After grinding carefully for 3 hours, a uniform primary sintered mixed powder is obtained, which is naturally dried; the uniform primary sintered mixed powder is placed in a circular mold, and then a pressure of 10MPa is applied to press for 5 minutes, and then a pressure of 30MPa is applied to press for 10 minutes to obtain a circular target; the target is heated to 500°C at a rate of 5°C / min with the furnace and kept warm for 2 hours, and then heated to 830°C at a rate of 5°C / min and kept warm for 2 hours, and then cooled to room temperature with the furnace to obtain Bi 1.84 Pb 0.4 FeMnO 6 Ceramic target: (001) oriented SrTiO 3 The single crystal substrate and the ceramic target were placed on the heating platform and RF sputtering platform of the magnetron sputtering instrument respectively, and the background vacuum was reduced to 1×10 - 6 Torr, while maintaining the substrate temperature at 650°C; then Ar and O were introduced into the magnetron sputtering chamber 2 , ensuring Ar / O 2 The flow ratio is 3:7, the gas flow rate is 10sccm, and the working pressure is 0.4Pa; 1.6 Pb 0.4 FeMnO 6 The ceramic target was subjected to 90W RF power for 50 minutes of deposition, and then 60W RF power was applied for 10 minutes of deposition. Then, 100Pa of oxygen was introduced for annealing for 20 minutes to obtain a 42nm thick high-quality Bi 1.84 Pb 0.4 FeMnO 6 Multifunctional double perovskite epitaxial film. Its XRD Figure 4 As shown, there are only diffraction peaks of the film and the substrate, indicating the epitaxial nature of the film.

[0081] The above is a detailed introduction to an iron-manganese-based non-equivalent double perovskite epitaxial film, preparation process and application provided in the embodiment of the present application. The description of the above embodiment is only used to help understand the method and core idea of ​​the present application; at the same time, for those of ordinary skill in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0082] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be subject to that defined in the attached claims.

[0083] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0084] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0085] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. An iron-manganese-based non-equivalent double perovskite epitaxial film, characterized in that: The iron-manganese-based non-equivalent double perovskite epitaxial film is grown on a single crystal substrate, and the chemical formula of the iron-manganese-based non-equivalent double perovskite epitaxial film is: Bi 2- 2x Me 2x FeMnO6, wherein the value range of x is: 0.01-0.

5.

2. The iron-manganese-based non-equivalent double perovskite epitaxial thin film according to claim 1, characterized in that: The iron-manganese-based non-equivalent double perovskite epitaxial film has a tetragonal structure and a space group of P4mm.

3. The iron-manganese-based non-equivalent double perovskite epitaxial film according to claim 1, characterized in that: The single crystal substrate is SrTiO3, Nb-SrTiO3, La 0.7 Sr 0.3 MnO3 / SrTiO3 or SrRuO3 / SrTiO3.

4. The iron-manganese-based non-equivalent double perovskite epitaxial film according to claim 1, characterized in that: The Me is one of the metal elements of the second and fourth main groups.

5. A process for preparing the iron-manganese-based non-equivalent double perovskite epitaxial film according to any one of claims 1 to 4 by magnetron sputtering, characterized in that: The process includes three steps: S1) Select a corresponding single crystal substrate, clean it, blow it dry and set it aside for use; S2) preparing an iron-manganese based ceramic target; S3) placing the single crystal substrate processed by S1) and the iron-manganese-based ceramic target obtained by S2) in corresponding platforms, starting the heating platform to heat the substrate to a set temperature, and using radio frequency magnetron sputtering preparation technology to deposit a thin film on the iron-manganese-based ceramic target to obtain an iron-manganese-based multifunctional double perovskite epitaxial film.

6. The process according to claim 5, characterized in that The specific steps of S2) are: S2.1) Mix Bi2O3, Fe2O3, Mn2O3 and MeCO3 powders in a certain molar ratio in an agate mortar, add dispersant several times and grind for 1-2h to obtain a uniform mixed powder, and then dry it in an oven for later use; S2.2) sintering the mixed powder dried in S2.1) to obtain a primary sintered powder; S2.3) The primary sintered powder in S2.2) is placed in an agate mortar again, a binder and a dispersant are added, and the mixture is ground for 2-4 hours to obtain a uniform primary sintered mixed powder, which is then dried naturally for later use; S2.4) pressing the primary sintered mixed powder in S2.3) under certain conditions to obtain a pressed target; S2.5) Sintering the pressed target material in S2.4) under certain conditions to obtain an iron-manganese based ceramic target material.

7. The process according to claim 6, characterized in that The molar ratio of Bi2O3, Fe2O3, Mn2O3 and MeCO3 powders in S2.1) is: 2.3-2.3x: 1: 1: 4x, wherein the value range of x is: 0.01-0.5; The primary sintering conditions in S2.2) are: heating to 500°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, then heating to 750°C at a rate of 9.9-10.1°C / min and keeping the temperature for 0.9-1.1h, and then cooling to room temperature with the furnace; The pressing conditions in S2.4) are: pressing at a pressure of 9-11 MPa for 4.9-5.1 min, and then pressing at a pressure of 29-31 MPa for 9.9-10.1 min; The target sintering conditions in S2.5) are as follows: the temperature is raised to 500°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, then the temperature is raised to 830°C at a rate of 4.9-5.1°C / min and kept at that temperature for 1.9-2.1h, and then the temperature is lowered to room temperature with the furnace.

8. The process according to claim 5, characterized in that The specific process of the radio frequency magnetron sputtering preparation technology in S3) is: The vacuum degree is less than 1×10 -6 Torr, the single crystal substrate temperature is 649-651℃, the Ar / O2 flow ratio is 3:7, the total gas flow is 9.9-10.1sccm, the working gas pressure is 0.39-0.41Pa, the RF power is 89-91W for deposition for 49.5-50.5min, then 29-31W for deposition for 9.5-10.5min, and then annealing in 100-110Pa oxygen atmosphere for 19-21min.

9. The process according to claim 5, characterized in that The residual polarization intensity of the iron-manganese-based non-equivalent double perovskite epitaxial film obtained by the process is not less than 15 μC / cm 2 , saturation magnetization not less than 25emu / cc and open circuit voltage not less than 350μA / cm 2 .

10. An application of the iron-manganese-based double perovskite epitaxial film prepared by the process according to any one of claims 5 to 9 in the fields of ferroelectric, ferromagnetic, photovoltaic and photoelectrically coupled semiconductors.

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