A Fe3Ge single crystal and its preparation method and application

Abstract

The present invention provides an Fe3Ge single crystal and its preparation method and application, belonging to the field of topological material technology. The preparation method of the Fe3Ge single crystal provided by the present invention uses tin as a flux, and combines the control of the molar ratio of iron, germanium, and tin and the temperature, time, and cooling rate of crystal growth to prepare large-sized, high-crystalline-quality, and high-purity Fe3Ge single crystals. The unit cell parameters of the Fe3Ge single crystal prepared by the method provided by the present invention are that the lengths of the crystal axis a and the crystal axis b are 5.18Å, and the length of the crystal axis c is 4.23Å, respectively. The angle β between the crystal axis a and the crystal axis b on the (001) crystal plane is 58.7° and γ is 61.3°, and the Fe3Ge single crystal has a distorted cage lattice structure. The resistivity of the Fe3Ge single crystal decreases with decreasing temperature, and the Fe3Ge single crystal has very large anomalous thermal conductivity, which can meet the demand for large-sized, high-quality single crystals in the fields of storage, sensors, quantum computing, or quantum communication.

Description

Technical Field

[0001] The present invention relates to the technical field of topological materials, and in particular to an Fe3Ge single crystal and a preparation method and application thereof. Background Art

[0002] Since the theoretical and experimental confirmation of topological insulators in 2007, topological materials have garnered widespread attention in condensed matter physics. Their topologically protected surface and bulk states can exhibit novel physical properties distinct from those of conventional materials. Early research focused on non-magnetic topological insulators such as Bi2Se3 and Bi2Te3, whose dissipative surface states hold great promise for low-energy electronics. Furthermore, the kagome lattice structure has garnered significant attention due to its highly symmetrical and unique two-dimensional geometric arrangement, which produces a unique band structure when electrons move within it. Incorporating magnetism into the kagome lattice structure is expected to give rise to even richer topological states. From the perspective of fundamental condensed matter physics, magnetic kagome topological materials offer promising opportunities for the study of novel quantum phenomena. The various macroscopic quantum effects in these materials, such as the anomalous Hall effect and anomalous thermoelectric transport properties, hold great promise for future applications.

[0003] Hexagonal Fe3Ge has an Fe-Fe cage lattice and potentially rich topological states. To further investigate and uncover the topological properties and potential applications of Fe3Ge, the first challenge is to produce high-quality Fe3Ge single crystals. High-quality Fe3Ge single crystals are both the foundation and prerequisite for studying its topological properties and the most critical and important step in the entire research process. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides an Fe3Ge single crystal and a preparation method and application thereof. The preparation method of the Fe3Ge single crystal adopts Sn as a flux to prepare Fe3Ge single crystals with high crystallization quality, large size and high purity.

[0005] The specific technical solutions of the present invention are:

[0006] In a first aspect, the present invention provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0007] S1. Weighing raw materials: Under a protective atmosphere, iron, germanium, and tin are weighed and mixed to obtain a mixed raw material, wherein the molar ratio of the iron, germanium, and tin is 3:1:(15-20);

[0008] S2, crystal growth: the mixed raw material described in step S1 is subjected to crystal growth under a vacuum environment, wherein the holding temperature of the crystal growth is ≥1000°C and the holding time is ≥40h, and after the holding is completed, the temperature is lowered to 500-800°C at a cooling rate of ≤5°C / h to obtain an iron germanium crystal melt;

[0009] S3, post-processing: the iron germanium crystal melt in step S2 is centrifuged, cooled and flux removed to obtain Fe3Ge single crystal.

[0010] Furthermore, the protective atmosphere in step S1 is at least one of nitrogen and argon.

[0011] Furthermore, the molar ratio of iron, germanium and tin in step S1 is 3:1:20.

[0012] Furthermore, the process of weighing the raw materials in step S1 is performed in a glove box.

[0013] Furthermore, the process of forming the vacuum environment in step S2 is: placing the mixed raw materials in a container in an environment with a protective atmosphere, sealing the outlet of the container, taking out the container from the environment with a protective atmosphere, extracting the protective gas in the container, and using a hydrogen-oxygen machine to vacuum-pack the mixed raw materials in the container.

[0014] Furthermore, the time for the mixed raw materials in step S2 to rise from room temperature to the insulation temperature is 100-120 minutes.

[0015] Furthermore, the cooling rate in step S2 is ≤3.5°C / h.

[0016] Furthermore, the flux removal in step S3 adopts a dilute hydrochloric acid solution.

[0017] In a second aspect, the present invention provides an Fe3Ge single crystal, which belongs to the hexagonal crystal system, and the lengths of the crystal axis a and the crystal axis b in the unit cell parameters are 5.18Å, the length of the crystal axis c is 4.23Å, the angle β between the crystal axis a and the crystal axis b on the (001) crystal plane is 58.7°, and γ is 61.3°, and it has a distorted cage lattice structure. The aspect ratio of the Fe3Ge single crystal is ≥5, and the Fe3Ge single crystal is prepared by the above-mentioned Fe3Ge single crystal preparation method.

[0018] In a third aspect, the present invention provides applications of the above-mentioned Fe3Ge single crystal in storage, sensors, quantum computing or quantum communication.

[0019] The positive progress effect of the present invention is:

[0020] The preparation method of the Fe3Ge single crystal provided by the present invention uses tin as a flux, and combines the control of the molar ratio of iron, germanium, and tin and the temperature, time, and cooling rate of crystal growth to produce large-sized, high-quality, and high-purity Fe3Ge single crystals. The unit cell parameters of the Fe3Ge single crystal prepared by the method provided by the present invention include the lengths of the crystal axis a and the crystal axis b of 5.18Å, the length of the crystal axis c of 4.23Å, the angle β between the crystal axis a and the crystal axis b on the (001) crystal plane of 58.7° and γ of 61.3°, and the Fe3Ge single crystal has a distorted cage lattice structure. The aspect ratio of the Fe3Ge single crystal is ≥5. The resistivity of the Fe3Ge single crystal decreases with decreasing temperature, and the Fe3Ge single crystal has a very large anomalous thermal conductivity, which can meet the demand for large-sized, high-quality single crystals in the fields of storage, sensors, quantum computing, or quantum communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a microscope image of the Fe3Ge single crystal prepared in Example 1.

[0022] Figure 2 Schematic diagram of the lattice structure of Fe3Ge single crystal.

[0023] Figure 3 This is the EDS energy spectrum of the Fe3Ge single crystal prepared in Example 1.

[0024] Figure 4 3 is the curve of the resistivity of the Fe3Ge single crystal prepared in Example 1 in different directions as a function of temperature.

[0025] Figure 5 3 is a curve showing the change of anomalous thermal conductivity of the Fe3Ge single crystal prepared in Example 1 with temperature.

[0026] Figure 6 3 is a comparison chart of the anomalous thermal conductivity of the Fe3Ge single crystal prepared in Example 1 and other ferromagnetic samples. DETAILED DESCRIPTION

[0027] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only intended to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter ranges described in the present invention. Reasonable variations derived therefrom are still within the scope of protection of the claims of the present invention.

[0028] It should be noted that the endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0029] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventional meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents and instruments was carried out in accordance with the protocols and parameters given by the manufacturers.

[0030] In a first aspect, the present invention provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0031] S1. Weighing raw materials: Under a protective atmosphere, weigh iron, germanium, and tin, and mix them to obtain a mixed raw material, wherein the molar ratio of iron, germanium, and tin is 3:1:(15-20);

[0032] S2, crystal growth: the mixed raw materials in step S1 are subjected to crystal growth under a vacuum environment, the holding temperature of the crystal growth is ≥1000°C, the holding time is ≥40h, and after the holding is completed, the temperature is lowered to 500-800°C at a cooling rate of ≤5°C / h to obtain an iron germanium crystal melt;

[0033] S3, post-processing: the iron germanium crystal melt in step S2 is centrifuged, cooled and flux removed to obtain Fe3Ge single crystal.

[0034] The preparation method of the Fe3Ge single crystal provided by the present invention adopts tin as a flux. The solubility of tin to iron and germanium is moderate and tin and Fe3Ge do not chemically react at high temperature. Tin can effectively dissolve iron and germanium without easily introducing tin impurities into the Fe3Ge single crystal due to excessive dissolution. The molar ratio of iron, germanium and tin is controlled to be 3:1:(15-20) to ensure that the atomic ratio of iron and germanium in the raw materials meets the composition requirements of Fe3Ge and avoid the generation of impurity phases due to deviation in the raw material ratio. The high proportion of tin ensures that the liquid phase volume of the molten tin is large enough to completely dissolve iron and germanium atoms, expand the liquid phase area, reduce the melting point of the reaction system, and promote the diffusion of iron atoms and germanium atoms. During the crystal growth process, the temperature of the crystal growth is controlled to be 3:1:(15-20). ≥1000℃ and time ≥40h, which ensure the formation of Fe3Ge single crystal and suppress the formation of metastable phase, while being beneficial to the continuous growth of large-sized grains and reducing grain boundary defects; and the large degree of supercooling of tin is beneficial to the subsequent control of the cooling rate in the crystal growth process to achieve preferential growth of Fe3Ge single crystal, suppress the formation of amorphous and polycrystalline phases, and be beneficial to obtain Fe3Ge single crystal with few impurities and high phase purity; due to the density difference between tin and Fe3Ge, it is convenient to remove liquid tin by centrifugation, and combined with the subsequent further removal of flux, efficient purification of Fe3Ge can be achieved; therefore, the preparation method of Fe3Ge single crystal provided by the present invention can prepare large-sized, high-crystalline quality and high-purity Fe3Ge single crystal.

[0035] Furthermore, the protective atmosphere in step S1 is at least one of nitrogen and argon. Using at least one of nitrogen and argon to form a protective atmosphere can effectively isolate oxygen, prevent surface oxidation of iron, germanium, and tin, and ensure the chemical purity of the raw materials.

[0036] Furthermore, the molar ratio of iron, germanium, and tin in step S1 is 3:1:20. When the molar ratio of iron, germanium, and tin is 3:1:20, it is conducive to obtaining Fe3Ge single crystals with larger size and higher crystalline quality, providing an ideal raw material ratio condition for the efficient preparation of Fe3Ge single crystals.

[0037] Furthermore, the process of weighing the raw materials in step S1 is carried out in a glove box, which is easy to form an environment with a protective atmosphere and is also convenient for weighing the raw materials.

[0038] Furthermore, the process of forming the vacuum environment in step S2 is as follows: placing the mixed raw materials in a container in an environment with a protective atmosphere, sealing the outlet of the container, removing the container from the environment with a protective atmosphere, extracting the protective gas in the container, and using an oxyhydrogen machine to vacuum-pack the mixed raw materials in the container.

[0039] Furthermore, the time it takes for the mixed raw materials in step S2 to rise from room temperature to the holding temperature is 100-120 minutes. Tin has a melting point of 232°C. During the heating process, tin first melts into a liquid phase, encapsulating the iron and germanium. The 100-120 minute heating time ensures that the iron and germanium are fully dissolved in the liquid tin, facilitating the simultaneous dissolution and diffusion of the iron and germanium, which is beneficial for the uniform nucleation of the Fe3Ge single crystal.

[0040] Furthermore, the cooling rate in step S2 is ≤3.5°C / h. By further limiting the use of a lower cooling rate during the crystal growth process, it is beneficial to obtain a larger Fe3Ge single crystal.

[0041] Furthermore, the flux removal in step S3 is carried out using a dilute hydrochloric acid solution, which can effectively remove the residual tin on the surface of the Fe3Ge single crystal, and Fe3Ge is chemically stable in dilute hydrochloric acid and will not be corroded.

[0042] In a second aspect, the present invention provides an Fe3Ge single crystal. The Fe3Ge single crystal belongs to the hexagonal crystal system. In terms of unit cell parameters, the lengths of the crystal axis a and the crystal axis b are 5.18 Å, the length of the crystal axis c is 4.23 Å, the angles β between the crystal axis a and the crystal axis b on the (001) crystal plane are 58.7°, and γ is 61.3°. The Fe3Ge single crystal has a distorted cage lattice structure. The aspect ratio of the Fe3Ge single crystal is ≥5. The Fe3Ge single crystal is prepared by the above-mentioned Fe3Ge single crystal preparation method. The Fe3Ge single crystal prepared by the above-mentioned preparation method has larger unit cell parameters and has the advantages of high crystal quality, large size, and high purity.

[0043] In a third aspect, the present invention provides applications of the above-mentioned Fe3Ge single crystal in storage, sensors, quantum computing or quantum communication.

[0044] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0045] The technical solutions of the present invention are further described below with reference to specific examples. All reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment. The instruments used in the examples are also commercially available.

[0046] Example 1

[0047] This embodiment provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0048] S1. Weighing raw materials: In a nitrogen-filled glove box, weigh iron, germanium, and tin in a molar ratio of 3:1:20, place them in a crucible, and mix them evenly to obtain a mixed raw material. Place the crucible containing the mixed raw material in a quartz tube, plug the outlet of the quartz tube with quartz wool, and remove the quartz tube from the glove box.

[0049] S2, crystal growth: the quartz tube taken out in step S1 is installed on a vacuum packaging device, the nitrogen inside the quartz tube is extracted, and the quartz tube is vacuum-packaged using a hydrogen-oxygen machine; the vacuum-packaged quartz tube is placed in a muffle furnace, and the temperature in the muffle furnace is raised from room temperature to 1100° C. by heating for 120 minutes, and then kept at 1100° C. for 2880 minutes, and then cooled to 600° C. at a cooling rate of 5° C. / h, to obtain an iron-germanium crystal melt in the quartz tube;

[0050] S3, post-processing: After the quartz tube cooled to 600°C in step S2 is removed from the muffle furnace, it is inverted and placed in a centrifuge for centrifugation for 1 minute at a centrifuge speed of 2500 r / min. The quartz tube is taken out after it cools to room temperature; the quartz tube is opened and the Fe3Ge single crystal with a metallic luster is taken out, and the Fe3Ge single crystal is soaked in a diluted hydrochloric acid solution to remove impurities on its surface to obtain a high-quality Fe3Ge single crystal.

[0051] Example 2

[0052] This embodiment provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0053] S1. Weighing raw materials: In a nitrogen-filled glove box, weigh iron, germanium, and tin in a molar ratio of 3:1:20, place them in a crucible, and mix them evenly to obtain a mixed raw material. Place the crucible containing the mixed raw material in a quartz tube, plug the outlet of the quartz tube with quartz wool, and remove the quartz tube from the glove box.

[0054] S2, crystal growth: the quartz tube taken out in step S1 is installed on a vacuum packaging device, the nitrogen inside the quartz tube is extracted, and the quartz tube is vacuum-packaged using a hydrogen-oxygen machine; the vacuum-packaged quartz tube is placed in a muffle furnace, and the temperature in the muffle furnace is raised from room temperature to 1200° C. by heating for 100 minutes, and then kept at 1200° C. for 42 hours, and then cooled to 600° C. at a cooling rate of 5° C. / h, to obtain an iron-germanium crystal melt in the quartz tube;

[0055] S3, post-processing: After the quartz tube cooled to 600°C in step S2 is removed from the muffle furnace, it is inverted and placed in a centrifuge for centrifugation for 1 minute at a centrifuge speed of 2500 r / min. The quartz tube is taken out after it cools to room temperature; the quartz tube is opened and the Fe3Ge single crystal with a metallic luster is taken out, and the Fe3Ge single crystal is soaked in a diluted hydrochloric acid solution to remove impurities on its surface to obtain a high-quality Fe3Ge single crystal.

[0056] Example 3

[0057] This embodiment provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0058] S1. Weighing raw materials: In a nitrogen-filled glove box, weigh iron, germanium, and tin in a molar ratio of 3:1:20, place them in a crucible, and mix them evenly to obtain a mixed raw material. Place the crucible containing the mixed raw material in a quartz tube, plug the outlet of the quartz tube with quartz wool, and remove the quartz tube from the glove box.

[0059] S2, crystal growth: the quartz tube taken out in step S1 is installed on a vacuum packaging device, the nitrogen inside the quartz tube is extracted, and the quartz tube is vacuum-packaged using a hydrogen-oxygen machine; the vacuum-packaged quartz tube is placed in a muffle furnace, and the temperature in the muffle furnace is raised from room temperature to 1150° C. by heating for 120 minutes, and then kept at 1150° C. for 45 hours, and then cooled to 800° C. at a cooling rate of 3° C. / h, to obtain an iron-germanium crystal melt in the quartz tube;

[0060] S3, post-processing: After the quartz tube cooled to 800°C in step S2 is removed from the muffle furnace, it is inverted and placed in a centrifuge for centrifugation for 1 min at a centrifuge speed of 2500 r / min. The quartz tube is taken out after it cools to room temperature; the quartz tube is opened and the Fe3Ge single crystal with a metallic luster is taken out, and the Fe3Ge single crystal is soaked in a diluted hydrochloric acid solution to remove impurities on its surface to obtain a high-quality Fe3Ge single crystal.

[0061] Example 4

[0062] This embodiment provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0063] S1. Weighing raw materials: In a nitrogen-filled glove box, weigh iron, germanium, and tin in a molar ratio of 3:1:18, place them in a crucible, and mix them evenly to obtain a mixed raw material. Place the crucible containing the mixed raw material in a quartz tube, plug the outlet of the quartz tube with quartz wool, and remove the quartz tube from the glove box.

[0064] S2, crystal growth: the quartz tube taken out in step S1 is installed on a vacuum packaging device, the nitrogen inside the quartz tube is extracted, and the quartz tube is vacuum-packaged using a hydrogen-oxygen machine; the vacuum-packaged quartz tube is placed in a muffle furnace, and the temperature in the muffle furnace is raised from room temperature to 1000° C. by heating for 120 minutes, and then kept at 1000° C. for 50 hours, and then cooled to 500° C. at a cooling rate of 5° C. / h, to obtain an iron-germanium crystal melt in the quartz tube;

[0065] S3, post-processing: After the quartz tube cooled to 500°C in step S2 is removed from the muffle furnace, it is inverted and placed in a centrifuge for centrifugation for 1 minute at a centrifuge speed of 2500 r / min. The quartz tube is removed after it cools to room temperature; the quartz tube is opened and the Fe3Ge single crystal with a metallic luster is taken out, and the Fe3Ge single crystal is soaked in a dilute hydrochloric acid solution to remove impurities on its surface to obtain a high-quality Fe3Ge single crystal.

[0066] Example 5

[0067] This embodiment provides a method for preparing a Fe3Ge single crystal, comprising the following steps:

[0068] S1. Weighing raw materials: In a nitrogen-filled glove box, weigh iron, germanium, and tin in a molar ratio of 3:1:15, place them in a crucible, and mix them evenly to obtain a mixed raw material. Place the crucible containing the mixed raw material in a quartz tube, plug the outlet of the quartz tube with quartz wool, and remove the quartz tube from the glove box;

[0069] S2, crystal growth: the quartz tube taken out in step S1 is installed on a vacuum packaging device, the nitrogen inside the quartz tube is extracted, and the quartz tube is vacuum-packaged using a hydrogen-oxygen machine; the vacuum-packaged quartz tube is placed in a muffle furnace, and the temperature in the muffle furnace is raised from room temperature to 1050° C. by heating for 90 minutes, and then kept at 1050° C. for 46 hours, and then cooled to 700° C. at a cooling rate of 4° C. / h, to obtain an iron-germanium crystal melt in the quartz tube;

[0070] S3, post-processing: After the quartz tube cooled to 700°C in step S2 is removed from the muffle furnace, it is inverted and placed in a centrifuge for centrifugation for 1 minute at a centrifuge speed of 2500 r / min. The quartz tube is taken out after it cools to room temperature; the quartz tube is opened and the Fe3Ge single crystal with a metallic luster is taken out, and the Fe3Ge single crystal is soaked in a diluted hydrochloric acid solution to remove impurities on its surface to obtain a high-quality Fe3Ge single crystal.

[0071] The samples in the examples were characterized and tested, and the results were as follows:

[0072] Figure 1 This is a microscope image of the Fe3Ge single crystal obtained in Example 1. As can be seen from the image, the Fe3Ge single crystal is prismatic, has a metallic luster on the surface, is about 2 mm long, and has an aspect ratio greater than 5.

[0073] The Fe3Ge single crystal prepared in Example 1 was subjected to XRD test and its structure was analyzed. The crystal structure and lattice parameters of the Fe3Ge single crystal were obtained by analysis, as shown in Table 1 and Figure 2 As shown in Table 1 and Figure 2 It can be seen that the Fe3Ge single crystal obtained in Example 1 belongs toP 63 / mmc Each germanium atom is surrounded by 12 iron atoms distributed in a hexagonal star shape. The lengths of the crystal axis a and crystal axis b in the unit cell parameters are 5.1814(6)Å, and the length of the crystal axis c is 4.2308(5)Å. The angles β and γ between the crystal axis a and crystal axis b on the (001) crystal plane are 58.7° and 61.3°, respectively, showing a distorted cage lattice structure. The vertices of the hexagonal star formed by the iron atoms are 60°. Figure 1 、 Figure 2 As shown in Table 1, the preparation method provided by the present invention can successfully prepare large-sized Fe3Ge single crystals with a cage structure.

[0074] Table 1 Lattice parameter data of Fe3Ge single crystal prepared in Example 1

[0075]

[0076] The resistivity analysis test of the Fe3Ge single crystal prepared in Example 1 was carried out to test the change of the resistivity of the Fe3Ge single crystal in the X direction and the Z direction with temperature. The results are as follows: Figure 4 As shown, it can be seen that the resistivity of Fe3Ge single crystal in the X direction and Z direction decreases with decreasing temperature, showing metallic behavior.

[0077] The Fe3Ge single crystal prepared in Example 1 was subjected to a thermal conductivity analysis test to test the change of the thermal conductivity of the Fe3Ge single crystal with temperature. The test results are as follows: Figure 5 As shown in Figure 1, the thermal conductivity of the Fe3Ge single crystal obtained in Example 1 gradually increases with increasing temperature and stabilizes after the temperature reaches 200K. The thermal conductivity of the Fe3Ge single crystal reaches above 4 A / mK, indicating that the Fe3Ge single crystal has a very large anomalous thermal conductivity. The comparison results of the anomalous thermoelectric properties with other existing ferromagnetic materials are shown in Figure 1. Figure 6 As shown, it can be seen that compared with existing ferromagnetic materials, the anomalous thermal conductivity of the Fe3Ge single crystal prepared in Example 1 is significantly higher than that of Fe, Co, Fe3O4, Nd2Mo2O7, SrRuO3, FePt, MnSi and Fe3Sn2, and slightly higher than that of Co3Sn2S2 and Co2MnGa.

[0078] The sample 1 prepared in the embodiment was subjected to energy spectrum test, and the results are shown in Table 2 and Figure 3 shown.

[0079] Table 2 Energy spectrum test results of sample 1

[0080]

[0081] From Table 2 and Figure 3It can be seen that the Fe3Ge single crystal obtained in Example 1 contains two elements, Fe and Ge, with the element percentages of Fe and Ge being 75.35 and 24.65 respectively, and the molar ratio being 3.06:1, which is very close to the ideal value of Fe3Ge of 3:1.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing Fe3Ge single crystal, characterized in that: The following steps are involved: S1. Weighing raw materials: Under a protective atmosphere, iron, germanium, and tin are weighed and mixed to obtain a mixed raw material, wherein the molar ratio of the iron, germanium, and tin is 3:1:(15-20); S2, crystal growth: the mixed raw material in step S1 is subjected to crystal growth under a vacuum environment, the holding temperature of the crystal growth is ≥1000°C, the holding time is ≥40h, and after the holding is completed, the temperature is lowered to 500-800°C at a cooling rate of ≤5°C / h to obtain an iron germanium crystal melt; S3, post-processing: the iron germanium crystal melt in step S2 is centrifuged, cooled and flux removed to obtain Fe3Ge single crystal.

2. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The protective atmosphere in step S1 is at least one of nitrogen and argon.

3. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The molar ratio of iron, germanium and tin in step S1 is 3:1:

20.

4. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The process of weighing the raw materials in step S1 is carried out in a glove box.

5. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The process of forming the vacuum environment in step S2 is as follows: placing the mixed raw materials in a container in an environment with a protective atmosphere, sealing the outlet of the container, removing the container from the environment with a protective atmosphere, extracting the protective gas in the container, and using an oxyhydrogen machine to vacuum-pack the mixed raw materials in the container.

6. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The time for heating the mixed raw materials from room temperature to the insulation temperature in step S2 is 100-120 minutes.

7. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The cooling rate in step S2 is ≤3.5°C / h.

8. The method for preparing Fe3Ge single crystal according to claim 1, characterized in that: The flux removal in step S3 is carried out using a dilute hydrochloric acid solution.

9. An Fe3Ge single crystal, characterized in that The Fe3Ge single crystal belongs to the hexagonal crystal system, and the lengths of the crystal axis a and the crystal axis b in the unit cell parameters are 5.18Å, and the length of the crystal axis c is 4.23Å, respectively. The angles β and γ between the crystal axis a and the crystal axis b on the (001) crystal plane are 58.7° and 61.3°, respectively, and the Fe3Ge single crystal has a distorted cage lattice structure. The aspect ratio of the Fe3Ge single crystal is ≥5, and the Fe3Ge single crystal is prepared by the preparation method of the Fe3Ge single crystal according to any one of claims 1 to 8.

10. An application of Fe3Ge single crystal in storage, sensor, quantum computing or quantum communication, characterized in that: The Fe3Ge single crystal belongs to the hexagonal crystal system, and the lengths of the crystal axis a and the crystal axis b in the unit cell parameters are 5.18Å, and the length of the crystal axis c is 4.23Å, respectively. The angles β and γ between the crystal axis a and the crystal axis b on the (001) crystal plane are 58.7° and 61.3°, respectively, and the Fe3Ge single crystal has a distorted cage lattice structure. The aspect ratio of the Fe3Ge single crystal is ≥5, and the Fe3Ge single crystal is prepared by the preparation method of the Fe3Ge single crystal according to any one of claims 1 to 8.

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