Antiferromagnetic metal single crystal with three-dimensional stacking ordered structure and preparation method of antiferromagnetic metal single crystal

Abstract

The invention discloses an antiferromagnetic metal single crystal with a three-dimensional stacking ordered structure and a preparation method of the antiferromagnetic metal single crystal. The preparation method comprises the following steps: uniformly mixing Fe powder, Co powder, Ge powder and Te powder, and then loading the mixture into a quartz tube together with a transport agent; putting the sealed quartz tube into a double-temperature-zone tubular furnace for calcining to obtain the antiferromagnetic metal single crystal; a unit cell of the antiferromagnetic metal single crystal is formed by stacking a plurality of layer structures layer by layer, and each layer structure is provided with two Te layers, a Ge layer and a Fe / Co layer, wherein the Ge layer and the Fe / Co layer are respectively positioned between the two Te layers; the plurality of layer structures are grouped in pairs to form a plurality of layer groups which are sequentially stacked, the two layer structures in the same layer group are in an AA stacking mode, and the two layer structures in the two adjacent layer groups are in an ordered staggered stacking mode. The antiferromagnetic metal single crystal has the characteristics of good cruising antiferromagnetism, neel temperature higher than room temperature, three-dimensional stacking ordered structure and the like, and promotes the development of related fields.

Description

Technical Field

[0001] This invention relates to the field of quantum functional magnetic materials technology, and in particular to an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure and its preparation method. Background Technology

[0002] In the field of two-dimensional materials research, van der Waals materials have become one of the hot topics in materials science and condensed matter physics research in recent years due to their unique layered structure and rich physical properties. These materials are composed of a layered structure, with each layer bonded by strong covalent or ionic bonds with relatively strong binding energy, forming a stable two-dimensional planar structure; while the layers interact with each other through relatively weak van der Waals forces. This weak interaction allows the layers to be peeled off or stacked relatively easily, thus exhibiting electrical, magnetic, and optical properties.

[0003] In two-dimensional magnetic materials, by precisely controlling parameters such as the stacking sequence and stacking angle between layers, ferromagnetic and antiferromagnetic coexistence can be achieved at extreme layer thicknesses. This controllability provides an important means to explore novel physical phenomena in low-dimensional magnetic materials (such as moiré magnetism and spin superconductivity). Significant progress has been made in controlling interlayer stacking at the two-dimensional scale, but due to the complex thermodynamic and kinetic processes involved in material growth, achieving orderly control of interlayer stacking at the three-dimensional scale remains a highly challenging frontier problem.

[0004] Among numerous two-dimensional magnetic materials, the Fe-Ge-Te group possesses large magnetic anisotropy and high magnetic transition temperatures, providing a potential material basis for the development of room-temperature spintronic devices and attracting widespread interest from researchers. For example: 1) Fe5GeTe2 single-crystal materials have achieved Curie transition temperatures Ti higher than room temperature. C 1) The K value is approximately 310 K. 2) By doping Fe5GeTe2 with Co, the magnetic properties of the sample can be significantly controlled. Specifically, as the Co doping concentration increases, the ground state changes from ferromagnetic to antiferromagnetic. Simultaneously, changes in the Fe and Co ratio also alter the interlayer stacking pattern, affecting the magnetoelectric behavior of the material. In addition to elemental doping, annealing is also an effective method for controlling the stacking order. For example, during TaS2 growth, annealing can transform the interlayer stacking from a neat arrangement to a stepped arrangement, thereby changing its electronic structure and superconducting properties. However, due to the complex kinetic processes during material growth and the weak interlayer interactions, achieving precise control of three-dimensional interlayer stacking and preparing two-dimensional magnetic single crystals with special stacking structures remains a highly challenging problem.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] To overcome the above-mentioned defects, this invention provides an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure and its preparation method. The preparation method is reasonable, simple and feasible. The antiferromagnetic metal single crystal produced has good itinerant antiferromagnetism and a Nell temperature above room temperature, while also having a special three-dimensional stacked ordered structure, which greatly promotes the application development in related fields.

[0007] The technical solution adopted by this invention to solve its technical problem is: an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure, wherein the molecular formula of the antiferromagnetic metal single crystal is (Fe 0.52 Co 0.48 ) 5-x GeTe2, where 0≤x≤0.2; The unit cell of the antiferromagnetic metal single crystal is composed of several layered structures stacked one on top of another. Each layered structure has two Te layers, and a Ge layer and an Fe / Co layer located between the two Te layers respectively. Several layered structures are grouped in pairs to form several layer groups stacked sequentially. The two layered structures in the same layer group are stacked in an AA stacking manner, and the two layered structures in two adjacent layer groups are stacked in an ordered staggered stacking manner.

[0008] As a further improvement of the present invention, the two layer structures located in two adjacent layer groups are arranged in an AB stacking manner.

[0009] As a further improvement of the present invention, there is a positional deviation of L / 3 between two layer structures located in two adjacent layer groups, where L is the horizontal spacing between two adjacent Te atoms in the layer structure; Meanwhile, several of the aforementioned layers are distributed in a step-by-step manner.

[0010] As a further improvement of the present invention, each of the layer structures exhibits ferromagnetic interaction within its layer and antiferromagnetic interaction between two adjacent layer structures.

[0011] As a further improvement of the present invention, in each of the layer structures, the atomic ratio of Fe to Co is 2.6:2.4.

[0012] As a further improvement of the present invention, the antiferromagnetic metal single crystal has an antiferromagnetic Nell temperature of not less than 380K, and has two spin flips at a low temperature of 2K, with spin flip fields of 3.4T and 5T at the two spin flips, respectively.

[0013] As a further improvement of the present invention, the antiferromagnetic metal single crystal is a silver-white bulk, and a thin single crystal layer with a flat surface can be obtained by mechanically peeling the antiferromagnetic metal single crystal.

[0014] As a further improvement of the present invention, when a single crystal thin layer consisting of two said layer structures is obtained by mechanical peeling, the single crystal thin layer as a whole exhibits antiferromagnetic properties. When a single-crystal thin layer consisting of three or four of the aforementioned layer structures is obtained by mechanical exfoliation, the single-crystal thin layer as a whole exhibits ferromagnetic properties. When a single-crystal thin layer consisting of five or more layers is obtained by mechanical peeling, the single-crystal thin layer as a whole exhibits the coexistence of antiferromagnetic and ferromagnetic properties. In addition, the temperatures at which the single-crystal thin layer undergoes ferromagnetic and antiferromagnetic transitions are both higher than room temperature.

[0015] This invention also provides a method for preparing an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure, comprising the following steps: S1: After mixing Fe powder, Co powder, Ge powder, and Te powder evenly according to the formula ratio, they are loaded into a quartz tube along with the formula amount of transport agent; then the air pressure in the quartz tube is evacuated to below 1×10⁻⁶. -5 After Pa, the tube is sealed using a vacuum arc sealing furnace; S2: The sealed quartz tube is placed in a dual-temperature zone tube furnace and calcined at 780°C for 2-3 days. Then, it is calcined at a high temperature zone of 800-900°C and a low temperature zone of 700-750°C for 7-8 days. After that, it is cooled to room temperature with the furnace to obtain the antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure.

[0016] As a further improvement of the present invention, the stoichiometric ratio of Fe powder, Co powder, Ge powder and Te powder is 2.6:2.4:1:2; The transport agent is iodine powder, and the density of the iodine powder is 5-8 mg / cm³. 3 The amount added is 8% to 10% of the total weight of the Fe powder, Co powder, Ge powder and Te powder.

[0017] The beneficial effects of this invention are: 1) The antiferromagnetic metal single crystal obtained by this invention has a special three-dimensional stacked ordered structure, specifically manifested as follows: the two layer structures located in the same layer group exhibit an AA stacking pattern, and the two layer structures located in two adjacent layer groups exhibit an AB stacking pattern. This special three-dimensional stacking structure not only affects the crystal symmetry of the material, but also has a profound impact on its magnetic properties. For example, this three-dimensional stacked ordered structure can induce more complex magnetic ordered states, such as double spin flipping phenomena. At the same time, when the single crystal thin layer is reduced to the atomic layer thickness, it exhibits an odd-even layer magnetic change that is different from that exhibited by traditional layered antiferromagnetic materials. In summary, the antiferromagnetic metal single crystal material with a special three-dimensional stacked ordered structure obtained by this invention not only expands the research scope of antiferromagnetic materials, but also provides new possibilities for its application in fields such as spintronics, magnetic storage, and quantum computing. This enables the obtained antiferromagnetic metal single crystal to be used to fabricate more promising functional devices, and has a positive promoting effect on the application development in related fields. 2) The antiferromagnetic metal single crystal obtained by this invention possesses superior itinerant antiferromagnetism and a Nell temperature above room temperature. Specifically, the itinerant antiferromagnetism manifests as: good metallic properties, coexistence of ferromagnetism and antiferromagnetism in the ground state, tunable interlayer coupling between ferromagnetic and antiferromagnetic layers, and stable two-dimensional long-range ferromagnetism in few-layer and single-layer devices. Therefore, the antiferromagnetic metal single crystal provided by this invention is an ideal material for spintronics mechanism research and the realization of high-performance, low-power spintronic devices, and will positively promote application development in related fields. 3) The preparation method of the antiferromagnetic metal single crystal provided by this invention is reasonable, simple, feasible, and has low implementation cost. Attached Figure Description

[0018] Figure 1 The antiferromagnetic metal single crystal (abbreviated as Fe) obtained in Example 1 of this invention 2.6 Co 2.4 Flowchart of GeTe2 single crystal preparation process; Figure 2 Fe obtained in this invention 2.6 Co 2.4 X-ray diffraction pattern of GeTe2 single crystal; Figure 3 Fe obtained in this invention 2.6 Co 2.4 Aberration transmission electron microscopy (TEM) image of GeTe2 single crystal; Figure 4 Fe obtained in this invention 2.6 Co 2.4 A graph showing the electrical transport test results of GeTe2 single crystals; where the "black curve" indicates Fe. 2.6 Co 2.4The graph shows the Hall resistance of GeTe2 single crystal as a function of magnetic field at a low temperature of 2K. The "gray curve" indicates the Fe... 2.6 Co 2.4 The curve of low-temperature magnetoresistance of GeTe2 single crystal as a function of magnetic field at a low temperature of 2K; Figure 5 Fe obtained from this invention 2.6 Co 2.4 The graph shows the Hall resistance of single-crystal thin layers obtained by mechanical exfoliation on GeTe2 single crystals as a function of magnetic field at different numbers of layers; among them, Figure 5 Figure (a) shows the Hall resistance of a single-crystal thin layer composed of two of the aforementioned layer structures as a function of a magnetic field; Figure (b) shows the Hall resistance of a single-crystal thin layer composed of three of the aforementioned layer structures as a function of a magnetic field; Figure (c) shows the Hall resistance of a single-crystal thin layer composed of four of the aforementioned layer structures as a function of a magnetic field; and Figure (d) shows the Hall resistance of a single-crystal thin layer composed of five of the aforementioned layer structures as a function of a magnetic field. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0020] This invention provides an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure and its preparation method. The preparation method is reasonable, simple, and feasible. The fabricated antiferromagnetic metal single crystal possesses excellent itinerant antiferromagnetism and a Nell temperature above room temperature, while also exhibiting a unique three-dimensional stacked ordered structure, greatly promoting application development in related fields. The reason for this achievement lies mainly in the optimization and innovation of the raw material formulation and preparation method of the antiferromagnetic metal single crystal material, as detailed below: I. Preparation of antiferromagnetic metal single crystals with a three-dimensional stacked ordered structure as described in this invention. Example

[0021] Please see the appendix Figure 1 As shown, this embodiment 1 provides a method for preparing an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure, including the following fabrication steps: S1: After uniformly mixing Fe powder, Co powder, Ge powder, and Te powder according to the formula ratio, the mixture, along with the prescribed amount of transport agent, is loaded into a quartz tube; then, the air pressure in the quartz tube is evacuated to below 1×10⁻⁶. -5 After Pa, the tube is sealed using a vacuum arc sealing furnace.

[0022] Furthermore, the specific preparation method of the above-mentioned S1 is as follows: S11: According to the raw material formula listed in Table 1, Fe powder, Co powder, Ge powder and Te powder are mixed evenly in a glove box to obtain a mixed powder. The stoichiometric ratio of Fe powder, Co powder, Ge powder and Te powder is 2.6:2.4:1:2; understandably, the above stoichiometric ratio is the ratio of moles.

[0023]

[0024] Note: The Fe powder, Co powder, Ge powder and Te powder used in this embodiment are all commercially available analytical grade products, but the present invention does not limit the specific source of the above materials.

[0025] S12: Grind the obtained mixed powder in a mortar for a set time (e.g., 1 hour or more) to make the particle size of the mixed powder reach 100-200 mesh, so as to ensure better crystallization quality when the mixed powder is calcined and grown in the subsequent process.

[0026] Note: The particle size of the ground mixed powder can be precisely controlled according to processing requirements, but is not limited to 100 mesh or 200 mesh.

[0027] S13: A density of 5–8 mg / cm³ 3 The iodine powder added in an amount of 0.2g is placed together with the mixed powder prepared in S12 into a clean quartz tube with a groove, and then the quartz column is placed into the quartz tube and sealed with a sealing film.

[0028] Note: ① The above S13 is carried out in a glove box; ② During the process of loading the mixed powder into the quartz tube, avoid getting the powder on the opening of the quartz tube, so as not to affect the subsequent sealing quality.

[0029] S14: Remove the quartz tube, filled with materials and sealed, from the glove box, and then use a combination of mechanical and molecular pumps to evacuate the air pressure in the quartz tube to below 1×10⁻⁶. -5 After Pa, the tube is sealed using a vacuum arc sealing furnace.

[0030] S2: Place the sealed quartz tube into a dual-temperature zone tube furnace, calcine it at 780°C for 2-3 days (e.g., 2 days), then calcine it at a high-temperature zone of 800-900°C (e.g., 850°C) and a low-temperature zone of 700-750°C (e.g., 750°C) for 7-8 days (e.g., 8 days). Afterward, cool it to room temperature with the furnace to obtain the antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure (hereinafter referred to as Fe). 2.6 Co 2.4 GeTe2 single crystal). The Fe 2.6 Co 2.4 GeTe2 single crystals are silvery-white bulk crystals with centimeter-sized particles. They are not easily oxidized, are easily peeled off, and can be obtained by processing the Fe...2.6 Co 2.4 Mechanical exfoliation of GeTe2 single crystals can yield thin, flat single-crystal layers.

[0031] The aforementioned dual-temperature zone tube furnace is a 1200℃ dual-temperature zone tube furnace of model SN1200-GSL80B. The heating rate of the dual-temperature zone tube furnace can reach 4-6℃ / min, which can effectively avoid affecting the structure of the calcined powder.

[0032] Understandably, this application obtains antiferromagnetic metal single crystal materials with a special three-dimensional stacked ordered structure by precisely controlling the formulation (especially the ratio of Fe atoms to Co atoms) and particle size of the mixed powder, the formulation and density of the transport agent, and the calcination processing parameters.

[0033] II. Fe obtained in this application 2.6 Co 2.4 Performance testing of GeTe2 single crystal.

[0034] Fe prepared in Example 1 of the present invention 2.6 Co 2.4 Multiple performance tests and analyses were conducted on GeTe2 single crystals. The specific test content and results are as follows: 2.1) Fe obtained in Example 1 of the present invention 2.6 Co 2.4 Characterization and analysis methods and results of GeTe2 single crystals: The Fe prepared in Example 1 of this application was analyzed using a SmartLab X-ray diffractometer (Rigaku Corporation, Japan) and a Sigma 500 field emission scanning electron microscope (Carl Zeiss, Inc.). 2.6 Co 2.4 X-ray diffraction and chemical composition analysis were performed on GeTe2 single crystals. The test and analysis results are attached. Figure 2 As shown in Table 2 below.

[0035] Appendix Figure 2 Fe 2.6 Co 2.4 The X-ray diffraction pattern of GeTe2 single crystal shows that Fe... 2.6 Co 2.4 GeTe2 single crystals showed only c-direction diffraction peaks and no second phase was detected.

[0036] Table 2 below shows Fe 2.6 Co 2.4 The EDS elemental analysis chart of GeTe2 single crystals, as shown in Table 2, shows that the average atomic ratio of Fe, Co, Ge, and Te is 31.75:29.82:12.70:25.73, which basically conforms to the chemical formula Fe.2.6 Co 2.4 GeTe2.

[0037]

[0038] 2.2) Regarding the Fe obtained in Example 1 of this application 2.6 Co 2.4 Atomic-resolution structural characterization analysis of GeTe2 single crystals.

[0039] The Fe was measured using a 300 kV double-spherical aberration corrected transmission electron microscope. 2.6 Co 2.4 Atom-resolved structure of GeTe2 single crystal, test results are attached. Figure 3 As shown.

[0040] From the appendix Figure 3 It can be seen that Fe 2.6 Co 2.4 GeTe2 single crystal is composed of several layered structures stacked one on top of another. Each layered structure has two Te layers, and a Ge layer and an Fe / Co layer located between the two Te layers respectively. The several layered structures are paired up to form several layer groups stacked sequentially (that is, the two layered structures in each layer group are arranged adjacently). The two layered structures in the same layer group are arranged in an AA stacking manner, and the two layered structures in two adjacent layer groups are arranged in an ordered staggered stacking manner, specifically an AB stacking manner.

[0041] Note: ① From the appendix Figure 3 As can be seen, the layered structure has two Te layers, and a Ge layer and an Fe / Co layer located between the two Te layers. The Fe / Co layer can be understood as two Fe element layers, two Co element layers, and a mixed Fe / Co layer, because the Co element occupies the Fe1 position and part of the Fe2 position. The Fe1 and Fe2 positions refer to specific locations, not the ferrous ions (monovalent and divalent) as understood in chemistry. ② It is well known that "AA stacking" refers to the complete overlap / alignment of atoms in the two layered structures (as can be seen). Figure 3 (As shown by the green line in the image); "AB stacking" refers to a misalignment of atoms in the two layers, specifically: each atom in the upper layer falls between two atoms in the lower layer (as can be seen). Figure 3 (As shown by the red line in the image).

[0042] Furthermore, based on the above measurements, there is a positional deviation of L / 3 between the two layer structures located in two adjacent layer groups, where L is the horizontal spacing between two adjacent Te atoms in the layer structure; that is, it can be understood that the several layer groups are distributed in a step-by-step manner, which is very regular and orderly.

[0043] In summary, the Fe obtained in Example 1 of this application 2.6 Co 2.4 The unit cell of GeTe2 single crystal exhibits a three-dimensional ordered stacking / stacking structure composed of a combination of AA stacking and AB stacking, which has certain unique characteristics.

[0044] 2.3) Regarding the Fe obtained in Example 1 of this application 2.6 Co 2.4 Electrical performance tests were conducted on GeTe2 single crystals.

[0045] The Fe obtained in Example 1 of this application was measured using the PPMS integrated physical property measurement system manufactured by Quantum Design, Inc., USA. 2.6 Co 2.4 Electrical performance tests were conducted on GeTe2 single crystals. The test results are attached. Figure 4 As shown.

[0046] From the appendix Figure 4 As can be seen, under the low temperature condition of 2K, the Hall resistance curve exhibits obvious layered antiferromagnetic behavior, and with the increase of the magnetic field, two spin-flipping behaviors appear (see attached figure). Figure 4 The "black curve" in the figure shows that the spin-flipping fields during the two spin flips are 3.4T and 5T, respectively. Similarly, at a low temperature of 2K, the magnetoresistance MR curve in the antiferromagnetic state exhibits a constant resistance (see attached figure). Figure 4 (The "platform section" on the "grey curve" in the image), and as the magnetic field increases, the magnetic reluctance changes from negative to positive.

[0047] According to research and analysis, the Fe 2.6 Co 2.4 The electromagnetic properties exhibited by GeTe2 single crystals, such as double spin flips and magnetoresistance changes, are all caused by their unique three-dimensional ordered stacking structure. This also promotes the development of Fe... 2.6 Co 2.4 GeTe2 single crystals can be used to fabricate more promising functional devices (such as nanodevices).

[0048] 2.4) Regarding the Fe obtained from Example 1 of this application 2.6 Co 2.4 Electrical properties were tested on single-crystal thin layers obtained by mechanical exfoliation on GeTe2 single crystals.

[0049] Firstly, mechanical peeling (specifically, tape peeling, a commonly used technique) was employed to remove Fe... 2.6 Co 2.4 Single-crystal thin-layer samples with different atomic layer thicknesses were obtained on GeTe2 single crystals. Among them, single-crystal thin-layer sample one consists of two layer structures, single-crystal thin-layer sample two consists of three layer structures, single-crystal thin-layer sample three consists of four layer structures, and single-crystal thin-layer sample four consists of five layer structures.

[0050] Next, the electrical properties of the four single-crystal thin-layer samples prepared above were tested using the PPMS (Property Measurement System) manufactured by Quantum Design, Inc., USA. The test results are shown in the appendix. Figure 5 As shown.

[0051] From the appendix Figure 5 As can be seen from the figures: ① At different temperatures, single-crystal thin-layer sample one exhibits antiferromagnetic properties (see Figure (a) for details), and at a low temperature of 2K, the spin-flipping field of single-crystal thin-layer sample one is 2.3T. ② At different temperatures, single-crystal thin-layer samples two and three exhibit ferromagnetic properties (see Figures (b) and (c) for details), and at a low temperature of 2K, the coercive fields of single-crystal thin-layer samples two and three are 1.6T and 1.5T, respectively. ③ Single-crystal thin-layer sample four exhibits a coexistence of antiferromagnetic and ferromagnetic properties (see Figure (d) for details), and at a low temperature of 2K, the spin-flipping field of single-crystal thin-layer sample four is 4.9T. ④ The temperatures at which the above four single-crystal thin-layer samples undergo ferromagnetic and antiferromagnetic transitions are all higher than room temperature.

[0052] In summary, the antiferromagnetic metal single crystal (i.e., Fe) obtained by this invention 2.6 Co 2.4 GeTe2 single crystals possess excellent properties such as itinerant antiferromagnetism and a Nell temperature above room temperature, as well as a unique three-dimensional stacked ordered structure, which greatly promotes the development of applications in related fields.

[0053] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. An antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure, characterized in that: The molecular formula of the antiferromagnetic metal single crystal is (Fe 0.52 Co 0.48 ) 5-x GeTe2, where 0≤x≤0.2; The unit cell of the antiferromagnetic metal single crystal is composed of several layered structures stacked one on top of another. Each layered structure has two Te layers, and a Ge layer and an Fe / Co layer located between the two Te layers respectively. Several layered structures are grouped in pairs to form several layer groups stacked sequentially. The two layered structures in the same layer group are stacked in an AA stacking manner, and the two layered structures in two adjacent layer groups are stacked in an ordered staggered stacking manner.

2. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 1, characterized in that: The two layer structures located in two adjacent layer groups are stacked in an AB manner.

3. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 2, characterized in that: There is a positional deviation of L / 3 between two layer structures located in two adjacent layer groups, where L is the horizontal spacing between two adjacent Te atoms in the layer structure; Meanwhile, several of the aforementioned layers are distributed in a step-by-step manner.

4. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 1, characterized in that: Each of the aforementioned layer structures exhibits ferromagnetic interactions within its layer and antiferromagnetic interactions between adjacent layers.

5. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 1, characterized in that: In each of the layered structures, the atomic ratio of Fe to Co is 2.6:2.

4.

6. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 1, characterized in that: The antiferromagnetic metal single crystal has an antiferromagnetic Nell temperature of not less than 380K, and exhibits two spin flips at a low temperature of 2K, with spin flip fields of 3.4T and 5T at the two spin flips, respectively.

7. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 1, characterized in that: The antiferromagnetic metal single crystal is a silvery-white bulk. By mechanically peeling the antiferromagnetic metal single crystal, a thin, flat single crystal layer can be obtained.

8. The antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure according to claim 7, characterized in that: When a single-crystal thin layer consisting of two layers is obtained by mechanical peeling, the single-crystal thin layer as a whole exhibits antiferromagnetic properties. When a single-crystal thin layer consisting of three or four of the aforementioned layer structures is obtained by mechanical exfoliation, the single-crystal thin layer as a whole exhibits ferromagnetic properties. When a single-crystal thin layer consisting of five or more layers is obtained by mechanical peeling, the single-crystal thin layer as a whole exhibits the coexistence of antiferromagnetic and ferromagnetic properties. In addition, the temperatures at which the single-crystal thin layer undergoes ferromagnetic and antiferromagnetic transitions are both higher than room temperature.

9. A method for preparing an antiferromagnetic metallic single crystal with a three-dimensional stacked ordered structure, characterized in that: The production process includes the following steps: S1: After mixing Fe powder, Co powder, Ge powder, and Te powder evenly according to the formula ratio, they are loaded into a quartz tube along with the formula amount of transport agent; then the air pressure in the quartz tube is evacuated to below 1×10⁻⁶. -5 After Pa, the tube is sealed using a vacuum arc sealing furnace; S2: The sealed quartz tube is placed in a dual-temperature zone tube furnace and calcined at 780°C for 2-3 days. Then, it is calcined at a high temperature zone of 800-900°C and a low temperature zone of 700-750°C for 7-8 days. After that, it is cooled to room temperature with the furnace to obtain the antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure.

10. The method for preparing an antiferromagnetic metal single crystal with a three-dimensional stacked ordered structure according to claim 9, characterized in that: The stoichiometric ratio of the Fe powder, Co powder, Ge powder, and Te powder is 2.6:2.4:1:2; The transport agent is iodine powder, and the density of the iodine powder is 5-8 mg / cm³. 3 The amount added is 8% to 10% of the total weight of the Fe powder, Co powder, Ge powder and Te powder.

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