Ytterbium-doped iron selenide telluride superconducting material, and preparation method and use thereof

Abstract

The application provides a ytterbium-doped iron-selenium-tellurium superconducting material and a preparation method and application thereof, the superconducting material comprises iron elements, ytterbium elements, selenium elements and tellurium elements, and the molar ratio of the iron elements, the ytterbium elements, the selenium elements and the tellurium elements in the superconducting material is (0.5-1.5):(0.01-0.1):(0.1-1):(0.1-1). The application adopts a solid-phase sintering process and improves a sintering procedure, so that the total sintering time is reduced to about 60 hours, and the preparation efficiency of the superconducting material is improved. In addition, the prepared superconducting material is good in uniformity and high in density. Furthermore, the doping of the ytterbium elements can promote the formation of FeSeTe tetragonal phase and make the phase formation more uniform, improve the superconducting upper transition temperature, reduce the superconducting transition temperature width and improve the superconducting performance of the superconducting phase body.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-temperature superconducting material preparation methods, and particularly relates to a ytterbium-doped iron-selenium-tellurium superconducting material and a preparation method and application thereof. BACKGROUND

[0002] In 2008, Japanese scientists discovered superconductivity of 26K in LaFeAsO1-xFx, which opened the research of iron-based superconductors. In the same year, Hsu et al. discovered a new type of iron-based superconducting material FeSe. The superconducting layer of the FeSe-based superconducting material is only composed of-FeSe- layers, which is the simplest iron-based superconducting material known at present, and the superconducting upper transition temperature thereof is 8K. In order to improve the superconducting upper transition temperature, Te which is homologous to Se is doped into FeSe, and the superconducting upper transition temperature is improved to 15K. Thus, the FeSeTe superconducting material becomes an important part of the iron-based superconductors.

[0003] In order to improve the superconducting performance of the FeSe-based superconducting material, researchers have developed various effective measures. High-energy ball milling treatment of precursor powder, improvement of sintering procedure, annealing in different atmospheres, immersion treatment in different liquids, etc. Although different methods are helpful for phase formation and removal of interstitial iron, they do not start from the material itself. Therefore, the powder is doped in order to improve the superconducting performance of FeSeTe from the chemical element composition. The previous doping can be divided into metal and non-metal doping, and the metal doping is often focused on the elements in the same period as Fe, such as Cr, Mn, CO, Ni, etc., which all show slight improvement or inhibition of superconducting properties, and the sintered polycrystalline bulk superconducting transition width is relatively large, the phase formation process is complex, and the phase formation is uneven and easy to produce impurities. Therefore, exploring new metal element doping becomes an effective way to improve the superconducting performance of FeSeTe. SUMMARY

[0004] In view of the shortcomings of the prior art described above, the purpose of the present application is to provide a ytterbium-doped iron-selenium-tellurium superconducting material and a preparation method and application thereof, which are used to solve the problems in the prior art.

[0005] The first aspect of the present application provides a ytterbium-doped iron-selenium-tellurium superconducting material, which comprises iron elements, ytterbium elements, selenium elements and tellurium elements, and the molar ratio of the iron elements, the ytterbium elements, the selenium elements and the tellurium elements in the superconducting material is (0.5-1.5):(0.01-0.1):(0.1-1):(0.1-1).

[0006] Preferably, the molar ratio of the iron elements, the ytterbium elements, the selenium elements and the tellurium elements in the superconducting material is (0.9-1.1):(0.01-0.1):(0.1-0.5):(0.3-0.8).

[0007] Further preferably, the molar ratio of the iron element, the ytterbium element, the selenium element and the tellurium element in the superconducting material is (0.95-1.05):(0.01-0.05):(0.2-0.5):(0.5-0.8).

[0008] Preferably, the superconducting upper transition temperature of the superconducting material is ≥ 14.5 K; and / or, the transition temperature width of the superconducting material is ≤ 2.5 K.

[0009] In some preferred embodiments of the present application, the superconducting upper transition temperature of the superconducting material is ≥ 15 K; and / or, the transition temperature width of the superconducting material is ≤ 2 K.

[0010] The second aspect of the present application provides a method for preparing the ytterbium-doped iron-selenium-tellurium superconducting material as described above, comprising the following steps:

[0011] 1) mixing iron powder, selenium powder, tellurium powder and ytterbium powder uniformly to obtain a mixed powder;

[0012] 2) under a protective gas atmosphere, pressing the mixed powder in step 1) into a block, and vacuum sealing the block in a quartz tube;

[0013] 3) performing first sintering on the sealed quartz tube at 400-850°C, and the sintering time is 50-60 h;

[0014] 4) taking out the block after the first sintering and grinding it into a powder;

[0015] 5) under a protective gas atmosphere, pressing the powder in step 4) into a block, and vacuum sealing the block in a quartz tube;

[0016] 6) performing second sintering on the sealed quartz tube at 400-850°C, and the sintering time is 50-60 h.

[0017] The present application adopts twice sintering to reduce the voids in the material after the first sintering, so that the material is more uniform and denser.

[0018] Preferably, the purity of the iron powder, the selenium powder, the tellurium powder and the ytterbium powder is ≥ 99.9%

[0019] Preferably, the protective gas is one or both of nitrogen gas or inert gas.

[0020] Further preferably, the protective gas is argon.

[0021] Preferably, the pressure of the pressing in steps 2) and 5) above is 3 MPa-8 MPa, and the pressing time is 10 min-30 min.

[0022] Preferably, the vacuum degree in steps 2) and 5) above is ≤ 5 × 10- 4Pa.

[0023] Preferably, the first sintering in step 3) above adopts a three-step sintering method, including the following steps:

[0024] 1) Put the sealed quartz tube into a sintering furnace and heat it up to 450-500℃ at a rate of 0.5-1℃ / min and sinter at this temperature for 2-4h;

[0025] 2) Continue to heat it up to 800-850℃ at a rate of 2-3℃ / min and sinter at this temperature for 35-45h;

[0026] 3) Continue to cool it down to 400-450℃ at a rate of 2-3℃ / min and sinter at this temperature for 0.2-1h.

[0027] Preferably, the second sintering in step 6) above adopts a three-step sintering method, including the following steps:

[0028] 1) Put the sealed quartz tube into a sintering furnace and heat it up to 450-500℃ at a rate of 0.5-1℃ / min and sinter at this temperature for 2-4h;

[0029] 2) Continue to heat it up to 600-700℃ at a rate of 0.5-2℃ / min and sinter at this temperature for 35-45h;

[0030] 3) Continue to cool it down to 400-450℃ at a rate of 2-3℃ / min and sinter at this temperature for 0.2-1h.

[0031] The present application can prevent the rupture of the quartz tube used for sealing caused by the increase of the vapor pressure of selenium due to the too fast heating in the first step of the three-step sintering method, and also prevent the rapid gasification of selenium from the bulk to cause holes or uneven surface of the bulk.

[0032] Preferably, the method further comprises a cooling step, which is to naturally cool the quartz tube loaded with the bulk to 20-30℃ after the first sintering and the second sintering.

[0033] The present application provides an application of the superconducting material as claimed in claims 1-2 as a sputtering target.

[0034] As described above, the ytterbium-doped iron-selenium-tellurium superconducting material, the preparation method and the application thereof have the following beneficial effects:

[0035] 1. The present application adopts a solid-phase sintering process and adjusts the sintering temperature and the sintering time to uniformly dope ytterbium into the iron-selenium-tellurium superconducting material, thereby preparing a bulk with good uniformity and high density.

[0036] 2、The application adopts solid phase sintering process and improves sintering procedure, reduces total sintering time to about 60 hours, and improves the preparation efficiency of superconducting material.

[0037] 3、The doping of Yb element can promote the formation of FeSeTe tetragonal phase and make the phase more uniform, reduce the width of superconducting transition temperature, and improve the superconducting performance of the superconducting phase body while keeping the superconducting transition temperature large.

[0038] 4、The Yb element as a non-superconducting particle can be used as an effective pinning source and can also indirectly form defects in the superconducting material, providing more abundant pinning types and improving the superconducting current density. The above different aspects work together to effectively improve the superconducting performance of the FeSeTe target material. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The FeSeTe superconducting material prepared in Example 1 of the application is shown. 0.96 Yb 0.04 Se 0.4 Te 0.6 The resistance-temperature curve of the superconducting material.

[0040] Figure 2 The FeSeTe superconducting material prepared in Example 2 of the application is shown. 1.0 Yb 0.02 Se 0.4 Te 0.6 The X-ray diffraction pattern of the superconducting material.

[0041] Figure 3 The FeSeTe superconducting material prepared in Example 3 of the application is shown. 1.0 Yb 0.04 Se 0.4 Te 0.6 The resistance-temperature curve of the superconducting material. DETAILED DESCRIPTION

[0042] The embodiments of the application are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the application from the disclosure of the specification. The application can also be implemented or applied through other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the application.

[0043] Furthermore, it should be understood that the combination of one or more steps of the methods mentioned in the present application does not exclude that other steps of the method can be present before and / or after the mentioned combination of steps, unless otherwise indicated; it should also be understood that the combination of one or more devices / apparatuses mentioned in the present application does not exclude that other devices / apparatuses can be present before and / or after the mentioned combination of devices / apparatuses, unless otherwise indicated. Moreover, the numbering of the steps of the methods is merely a convenient identification of the steps for the sake of ease of reference, and does not constitute a limitation of the order of the steps of the methods, nor does it limit the scope of the application, which is defined by the appended claims. Changes or modifications of the relative positions and / or the order of the steps of the methods, without substantially altering the technical content of the application, are also deemed to fall within the scope of the application.

[0044] Before further description of the specific embodiments of the present application, it should be understood that the scope of the present application is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present application are used to describe specific embodiments and are not intended to limit the scope of the present application; in the specification and claims of the present application, the singular forms "a", "an" and "the" include the plural forms unless the context clearly indicates otherwise.

[0045] When the embodiments give a numerical range, it should be understood that, unless otherwise indicated by the present application, both ends of each numerical range and any number between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art. In addition to the specific methods, devices, materials used in the embodiments, any method, device and material of the prior art similar or equivalent to the methods, devices and materials described in the embodiments of the present application can also be used to implement the present application according to the mastery of the prior art by those skilled in the art and the description of the present application.

[0046] Embodiment 1

[0047] The present embodiment 1 provides a preparation method of ytterbium-doped iron-selenium-tellurium superconducting material, which specifically comprises the following steps:

[0048] Step 1: In an argon-protected glove box, iron powder, ytterbium powder, selenium powder and tellurium powder are mixed uniformly according to a molar ratio of 0.96:0.04:0.4:0.6 to obtain a mixed powder with a total mass of 2g. The purity of the above-mentioned iron powder, ytterbium powder, selenium powder and tellurium powder is not less than 99.9%.

[0049] Step 2: In an argon-protected glove box, the mixed powder is placed into a mold with an inner diameter of 0.5 inches, and the powder is pressed and formed by a cold pressing tablet machine, with a pressure of 6MPa and a pressing time of 10min, to obtain a pressed block.

[0050] Step 3: In the glove box under argon protection, the compact prepared in step 2 was put into a customized necked quartz tube and was clamped at the neck with a cylindrical quartz plug, and was fixed on a tube sealing machine. The quartz tube was vacuumized, and the vacuumization was stopped when the vacuum degree was not higher than 1x10 -4 Pa. The quartz tube was sealed by aiming a hydrogen-oxygen torch at the quartz plug.

[0051] Step 4: The sealed quartz tube containing the compact was put into a tube furnace for sintering, and was treated as follows: 10 h for temperature rising to 500 DEG C and sintering at 500 DEG C for 3 h; 2 h for temperature rising to 800 DEG C and sintering at 800 DEG C for 39 h; 2 h for temperature falling to 450 DEG C and sintering at 450 DEG C for 1 h. The total treatment time was 57 h. The furnace was cooled to room temperature.

[0052] Step 5: In the glove box under argon protection, the quartz tube after sintering was broken, and the compact was taken out and was ground to obtain a powder. The powder was put into a mold with an inner diameter of 0.5 inches, and was pressed by a cold pressing tablet machine to obtain a compact with a pressure of 4 MPa and a pressing time of 10 min.

[0053] Step 6: In the glove box under argon protection, the compact prepared in step 5 was put into a customized necked quartz tube and was clamped at the neck with a cylindrical quartz plug, and was fixed on a tube sealing machine. The quartz tube was vacuumized, and the vacuumization was stopped when the vacuum degree was not higher than 1x10 -4 Pa. The quartz tube was sealed by aiming a hydrogen-oxygen torch at the quartz plug.

[0054] Step 7: The sealed quartz tube containing the compact in step 6 was put into a tube furnace for sintering, and was treated as follows: 10 h for temperature rising to 500 DEG C and sintering at 500 DEG C for 3 h; 2 h for temperature rising to 700 DEG C and sintering at 700 DEG C for 39 h; 2 h for temperature falling to 450 DEG C and sintering at 450 DEG C for 1 h. The total treatment time was 57 h. After the furnace was cooled to room temperature, an iron-selenium-tellurium superconducting material was obtained, and its chemical formula was Fe 0.96 Yb 0.04 Se 0.4 Te 0.6 .

[0055] The superconducting performance of the Fe 0.96 Yb 0.04 Se 0.4 Te 0.6 prepared in this embodiment 1 was tested, and its resistance-temperature curve is shown in Figure 1 . As can be seen from Figure 1 , the Fe 0.96 Yb 0.04 Se 0.4 Te 0.6The superconducting upper transition temperature is 15K, and the superconducting transition temperature width is within 2K.

[0056] Example 2

[0057] On the basis of example 1, the molar ratio of iron powder, ytterbium powder, selenium powder and tellurium powder in this example 2 is modified to 1:0.02:0.4:0.6, which specifically includes the following steps:

[0058] Step 1: In an argon-protected glove box, iron powder, ytterbium powder, selenium powder and tellurium powder are mixed uniformly according to a molar ratio of 1:0.02:0.4:0.6 to obtain a total mass of 2g of mixed powder. The purity of the above-mentioned iron powder, ytterbium powder, selenium powder and tellurium powder is not less than 99.9%.

[0059] Step 2: In an argon-protected glove box, the mixed powder is placed into a mold with an inner diameter of 0.5 inches, and the powder is pressed and formed by a cold pressing tablet machine, with a pressure of 6MPa and a pressing time of 10min, to obtain a briquette.

[0060] Step 3: In an argon-protected glove box, the briquette prepared in step 2 is placed into a customized necked quartz tube and clamped at the necking part with a cylindrical quartz plug, and fixed on a tube sealing machine. The quartz tube is vacuumized, and the vacuumization is stopped when the vacuum degree is not higher than 1×10 -4 Pa, and the quartz tube is sealed by a hydrogen-oxygen torch.

[0061] Step 4: The sealed quartz tube containing the briquette is placed into a tube furnace for sintering, which is specifically processed as follows: 10h to 500℃ and sintering at 500℃ for 3h; 2h to 800℃ and sintering at 800℃ for 39h; 2h to 450℃ and sintering at 450℃ for 1h, and the total processing time is 57h. The furnace is cooled to room temperature.

[0062] Step 5: In an argon-protected glove box, the sintered quartz tube is broken, and the briquette is taken out and ground uniformly to obtain a powder. The powder is placed into a mold with an inner diameter of 0.5 inches, and the powder is pressed and formed by a cold pressing tablet machine, with a pressure of 4MPa and a pressing time of 10min, to obtain a briquette.

[0063] Step 6: In an argon-protected glove box, the briquette prepared in step 5 is placed into a customized necked quartz tube and clamped at the necking part with a cylindrical quartz plug, and fixed on a tube sealing machine. The quartz tube is vacuumized, and the vacuumization is stopped when the vacuum degree is not higher than 1×10 -4 Pa, and the quartz tube is sealed by a hydrogen-oxygen torch.

[0064] Step 7: Put the sealed quartz tube containing the compact in step 6 into a tube furnace for sintering, and the specific treatment is as follows: 10 h for temperature rising to 500 DEG C and sintering at 500 DEG C for 3 h; 2 h for temperature rising to 650 DEG C and keeping at 650 DEG C for 39 h; 2 h for temperature falling to 450 DEG C and keeping at 450 DEG C for 1 h, and the total time of the treatment is 57 h. After the furnace is cooled to room temperature, the iron selenium tellurium superconducting material is obtained, and its chemical formula is Fe 1.0 Yb 0.02 Se 0.4 Te 0.6 .

[0065] The Fe 1.0 Yb 0.02 Se 0.4 Te 0.6 prepared in Example 2 is subjected to X-ray diffraction test, and its X-ray diffraction spectrum is shown in Figure 2 It can be seen from Figure 2 that the Fe 1.0 Yb 0.02 Se 0.4 Te 0.6 prepared in Example 2 only has diffraction peaks of FeSeTe tetragonal phase, without impurity phase, which indicates that the doping of Yb does not produce impurities and does not make the crystal quality worse, and the addition of Yb promotes the phase formation of FeSeTe tetragonal phase and makes the phase formation more uniform.

[0066] Example 3

[0067] On the basis of Example 1, the molar ratio of the iron powder, the ytterbium powder, the selenium powder and the tellurium powder is further modified to 1:0.04:0.4:0.6 in Example 3, which specifically includes the following steps:

[0068] Step 1: In an argon-protected glove box, the iron powder, the ytterbium powder, the selenium powder and the tellurium powder are uniformly mixed according to the molar ratio of 1:0.04:0.4:0.6 to obtain a mixed powder with a total mass of 2 g. The purity of the above-mentioned iron powder, ytterbium powder, selenium powder and tellurium powder is not less than 99.9%.

[0069] Step 2: In the argon-protected glove box, the mixed powder is put into a mold with an inner diameter of 0.5 inches, and the powder is pressed and formed by a cold pressing tablet machine, the pressure is 6 MPa, and the pressing time is 10 min, to obtain a compact.

[0070] Step 3: In the argon-protected glove box, the compact prepared in step 2 is put into a customized necked quartz tube and clamped at the neck by a cylindrical quartz plug, and fixed on a tube sealing machine. The quartz tube is vacuumized, and the vacuumization is stopped when the vacuum degree is not higher than 1x10 -4 Pa, and the quartz plug is sealed by a hydrogen-oxygen torch.

[0071] Step 4: Put the sealed quartz tube containing the compact into a tube furnace for sintering, and the specific treatment is as follows: 10 h for temperature rising to 500 ℃ and sintering at 500 ℃ for 3 h; 2 h for temperature rising to 800 ℃ and keeping at 800 ℃ for 39 h; 2 h for temperature falling to 450 ℃ and keeping at 450 ℃ for 1 h, and the total time of the treatment is 57 h. The furnace is cooled to room temperature.

[0072] Step 5: In an argon-protected glove box, break the sintered quartz tube, take out the compact and grind it uniformly to obtain a powder, and then put the powder into a mold with an inner diameter of 0.5 inches, and use a cold pressing tablet machine to press the powder into a compact, the pressure is 4 MPa, and the pressing time is 10 min.

[0073] Step 6: In an argon-protected glove box, put the compact prepared in step 5 into a customized necked quartz tube and fix it at the neck with a cylindrical quartz plug, and fix it on a tube sealing machine, and vacuumize the quartz tube, and stop vacuumizing when the vacuum degree is not higher than 1 × 10 -4 Pa, and use a hydrogen-oxygen torch to seal the quartz plug.

[0074] Step 7: Put the sealed quartz tube containing the compact in step 6 into a tube furnace for sintering, and the specific treatment is as follows: 10 h for temperature rising to 500 ℃ and sintering at 500 ℃ for 3 h; 2 h for temperature rising to 700 ℃ and keeping at 700 ℃ for 39 h; 2 h for temperature falling to 450 ℃ and keeping at 450 ℃ for 1 h, and the total time of the treatment is 57 h. After the furnace is cooled to room temperature, an iron selenium tellurium superconducting material is obtained, and its chemical formula is Fe 1.0 Yb 0.04 Se 0.4 Te 0.6 .

[0075] The superconducting performance test is performed on the Fe 1.0 Yb 0.04 Se 0.4 Te 0.6 prepared in Example 3, and the resistance-temperature curve is as shown in Figure 3 From Figure 3 it can be seen that the superconducting upper transition temperature of the Fe 1.0 Yb 0.04 Se 0.4 Te 0.6 prepared in Example 3 is 14.5 K, and the superconducting transition temperature width is within 2.5 K.

[0076] Comparative Example 1

[0077] On the basis of Example 1, the ytterbium powder is replaced by manganese powder in Comparative Example 1 to prepare an iron selenium tellurium superconducting material doped with manganese, which specifically includes the following steps:

[0078] Step 1: In an argon-filled glove box, iron powder, manganese powder, selenium powder and tellurium powder were mixed uniformly according to a molar ratio of 0.96:0.04:0.4:0.6 to obtain a mixed powder with a total mass of 2 g. The purity of the above-mentioned iron powder, manganese powder, selenium powder and tellurium powder was not less than 99.9%.

[0079] Step 2: In an argon-filled glove box, the mixed powder was placed into a mold with an inner diameter of 0.5 inches, and a cold pressing tablet machine was used to press and form the powder, with a pressure of 6 MPa and a pressing time of 10 min, to obtain a briquette.

[0080] Step 3: In an argon-filled glove box, the briquette prepared in step 2 was placed into a customized necked quartz tube and clamped at the neck with a cylindrical quartz plug, and fixed on a tube sealing machine. The quartz tube was vacuumized, and the vacuumization was stopped when the vacuum degree was not higher than 1x10 -4 Pa. The quartz tube was sealed by aiming a hydrogen-oxygen torch at the quartz plug.

[0081] Step 4: The sealed quartz tube containing the briquette was placed into a tube furnace for sintering, and the specific treatment was as follows: 10 h for temperature rising to 500℃ and sintering at 500℃ for 3 h; 2 h for temperature rising to 800℃, and temperature keeping at 800℃ for 39 h; 2 h for temperature dropping to 450℃, and temperature keeping at 450℃ for 1 h. The total time of the treatment was 57 h. Natural cooling to room temperature.

[0082] Step 5: In an argon-filled glove box, the sintered quartz tube was broken, and the briquette was taken out and ground uniformly to obtain a powder. The powder was placed into a mold with an inner diameter of 0.5 inches, and a cold pressing tablet machine was used to press and form the powder, with a pressure of 4 MPa and a pressing time of 10 min, to obtain a briquette.

[0083] Step 6: In an argon-filled glove box, the briquette prepared in step 5 was placed into a customized necked quartz tube and clamped at the neck with a cylindrical quartz plug, and fixed on a tube sealing machine. The quartz tube was vacuumized, and the vacuumization was stopped when the vacuum degree was not higher than 1x10 -4 Pa. The quartz tube was sealed by aiming a hydrogen-oxygen torch at the quartz plug.

[0084] Step 7: The sealed quartz tube containing the briquette in step 6 was placed into a tube furnace for sintering, and the specific treatment was as follows: 10 h for temperature rising to 500℃ and sintering at 500℃ for 3 h; 2 h for temperature rising to 700℃, and temperature keeping at 700℃ for 39 h; 2 h for temperature dropping to 450℃, and temperature keeping at 450℃ for 1 h. The total time of the treatment was 57 h. After the furnace was cooled to room temperature, an iron selenium tellurium superconducting material was obtained, and its chemical formula was Fe 0.96 Mn 0.04 Se 0.4 Te 0.6 .

[0085] The superconducting performance of the heavily doped iron selenium tellurium superconducting material prepared in the comparative example 1 was tested, and the resistance starting transition temperature of the material was less than 12K, and the superconducting transition temperature width was greater than 3K.

[0086] Compared with the manganese-doped iron selenium tellurium superconducting material of the comparative example 1, the starting transition temperature of the ytterbium-doped iron selenium tellurium superconducting material prepared in the application was greater than 12K, and the superconducting transition temperature width was less than 2.5K. It is proved that the ytterbium-doped iron selenium tellurium superconducting material prepared in the application has a smaller superconducting transition temperature width, and its superconducting performance is higher. In addition, compared with example 1, the increase of the molar ratio of iron in example 3 will make the superconducting temperature lower and the superconducting transition temperature width wider, which is not conducive to the improvement of the superconducting performance of the material.

[0087] In summary, the ytterbium-doped iron selenium tellurium superconducting material prepared in the application has excellent conductive performance, and the doping of ytterbium can promote the formation of FeSeTe tetragonal phase and make the phase more uniform, reduce the superconducting transition temperature width, and improve the superconducting performance of the superconducting phase body; in addition, the ytterbium element as a non-superconducting particle can not only be used as an effective pinning source, but also indirectly form defects in the superconducting material, providing more abundant pinning types and improving the superconducting current density. The above different aspects work together to effectively improve the superconducting performance of the FeSeTe target material.

[0088] The above is only a preferred embodiment of the application, and is not a limitation on the form and substance of the application. It should be noted that for ordinary skilled persons in the art, some improvements and supplements can be made without departing from the method of the application, and these improvements and supplements should also be considered as the protection scope of the application. For those skilled in the art, some changes, modifications and equivalent changes made by utilizing the disclosed technical content without departing from the spirit and scope of the application are equivalent embodiments of the application; at the same time, any equivalent changes, modifications and evolution of the above-mentioned embodiments according to the essential technology of the application are still within the scope of the technical solutions of the application.

Claims

1. A ytterbium-doped iron selenium tellurium superconducting material, characterized in that, The superconducting material comprises iron, ytterbium, selenium, and tellurium, and the molar ratio of iron, ytterbium, selenium, and tellurium in the superconducting material is (0.5~1.5):(0.01~0.1):(0.1~1):(0.1~1); the superconducting material is prepared by the following steps: 1) Mix iron powder, selenium powder, tellurium powder and ytterbium powder evenly to obtain a mixed powder; 2) Under a protective gas atmosphere, the mixed powder from step 1) is pressed into a block and vacuum-sealed in a quartz tube; 3) The sealed quartz tube is sintered for the first time at 400~850℃ for 50~60h; 4) Remove the blocks after the first sintering and grind them into powder; 5) Under a protective gas atmosphere, the powder from step 4) is pressed into a block and vacuum-sealed in a quartz tube; 6) The sealed quartz tube is sintered for the second time at 400~850℃ for 50~60h.

2. The superconducting material according to claim 1, characterized in that, The superconducting upper transition temperature of the superconducting material is ≥14.5K; and / or, the transition temperature width of the superconducting material is ≤2.5K.

3. A method for preparing ytterbium-doped iron selenium tellurium superconducting material as described in claim 1 or 2, characterized in that, Includes the following steps: 1) Mix iron powder, selenium powder, tellurium powder and ytterbium powder evenly to obtain a mixed powder; 2) Under a protective gas atmosphere, the mixed powder from step 1) is pressed into a block and vacuum-sealed in a quartz tube; 3) The sealed quartz tube is sintered for the first time at 400~850℃ for 50~60h; 4) Remove the blocks after the first sintering and grind them into powder; 5) Under a protective gas atmosphere, the powder from step 4) is pressed into a block and vacuum-sealed in a quartz tube; 6) The sealed quartz tube is sintered for the second time at 400~850℃ for 50~60h.

4. The preparation method according to claim 3, characterized in that, The protective gas is one or both of nitrogen or inert gases.

5. The preparation method according to claim 4, characterized in that, The protective gas is argon.

6. The preparation method according to claim 3, characterized in that, The pressing pressure in steps 2) and 5) is 3MPa~8MPa, and the pressing time is 10min~30min.

7. The preparation method according to claim 3, characterized in that, The vacuum degree in steps 2) and 5) is ≤5×10 -4 Pa.

8. The preparation method according to claim 3, characterized in that, The first sintering in step 3) adopts a three-step sintering method, including the following steps: 1) Place the sealed quartz tube into a sintering furnace and heat it to 450℃~500℃ at a rate of 0.5~1℃ / min, then sinter at this temperature for 2h~4h; 2) Continue to raise the temperature to 800~850℃ at a rate of 2℃ / min~3℃ / min and sinter at this temperature for 35~45h; 3) Continue cooling at a rate of 2℃ / min~3℃ / min to 400~450℃ and sinter at this temperature for 0.2~1h.

9. The preparation method according to claim 3, characterized in that, The second sintering in step 6) adopts a three-step sintering method, including the following steps: 1) Place the sealed quartz tube into a sintering furnace and heat it to 450℃~500℃ at a rate of 0.5~1℃ / min, then sinter at this temperature for 2h~4h; 2) Continue to increase the temperature to 600~700℃ at a rate of 0.5℃ / min~2℃ / min and sinter at this temperature for 35~45 hours; 3) Continue cooling at a rate of 2℃ / min~3℃ / min to 400~450℃ and sinter at this temperature for 0.2~1h.

10. The preparation method according to claim 3, characterized in that, The method also includes a cooling step, wherein the cooling is performed by naturally cooling the quartz tube containing the bulk material to 20-30°C after the first and second sintering.

11. An application of the superconducting material as described in any one of claims 1 to 2 as a sputtering target.

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