Ga-based van der Waals room-temperature ferromagnetic crystalline materials, fabrication, and applications.

Abstract

The present invention discloses Ga-based van der Waals room temperature ferromagnetic crystal material, its manufacture and application, which belongs to the technical field of nanoparticle magnetic material manufacture. 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d Te2 (c=-0.2~0.2, d=0.01~0.5). Fe 3-a Ga b The growth method of Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) is a self-supporting flux method in which excess Ga and Te are used as fluxes to grow the crystal. 5-c GeGa d The growth method of Te2 (c=-0.2~0.2, d=0.01~0.5) is a chemical vapor transport method using elemental iodine as a transport agent for growing the crystal. The Ga-based van der Waals room temperature ferromagnetic crystal Fe 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d The composition of the Te2 (c=-0.2~0.2, d=0.01~0.5) material is uniform, has a van der Waals structure, and is easy to mechanically peel off. The Curie temperatures are 330~367K and 320~345K, respectively, and the saturation magnetic moments are 50~57.2emu / g and 80~88.5emu / g, respectively. Fe 3-a Ga b The perpendicular magnetic anisotropy of Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) single crystal is 3.25 × 10 5 ~4.79×10 5 J / m 3 It has also reached

Description

[Technical Field]

[0001] This invention relates to manufacturing techniques for nanoparticle magnetic materials, and more specifically, to Ga-based van der Waals room-temperature ferromagnetic crystalline materials, their manufacturing, and applications. [Background technology]

[0002] Magnetism arises from the movement and spin rotation of charged elementary particles, and has brought about a scientific revolution in important technologies such as data storage and biomedical imaging. It will continue to bring about new phenomena in the development of new materials and the miniaturization of devices. Ferromagnetic materials can exhibit ferromagnetic ordered states in three-dimensional space, but due to the theoretical limit of the Mermin-Wagner theorem, it is difficult to search for intrinsic ferromagnetic materials in two-dimensional systems. This theorem rigorously proves that long-range magnetic order is impossible in two-dimensional isotropic Heisenberg spin systems because thermodynamic fluctuations destroy all ordered states. Until recently, experimental research on two-dimensional ferromagnetic materials has made groundbreaking progress. In just the last few years, we have seen advances in CrI3, Cr2Ge2Te6, Fe n Ferromagnetic ordering phenomena have been observed using two-dimensional van der Waals crystals with van der Waals structures, such as GeTe2 (n=3, 4, 5). This series of two-dimensional van der Waals ferromagnetic crystals and their heterostructures not only contain rich physical mechanisms and intriguing electronic properties, but also opens up new research fields for various unique quantum effects, such as the quantum anomalous Hall effect, and is expected to provide a material foundation for realizing multifunctional quantum devices.

[0003] However, the recent discovery of two-dimensional van der Waals intrinsic magnetic crystals has promoted the development of various multifunctional spintronics devices such as intrinsic two-dimensional magnetism, tunnel electron magnetic detection, spin quantum sensors, giant tunnel magnetoresistance, and spintronics. However, since the Curie temperature of all these devices is very low, these devices can still only operate under temperature conditions much lower than room temperature. Therefore, there are still challenges in manufacturing intrinsic two-dimensional van der Waals magnetic crystals with super-room-temperature Curie temperature, large saturation magnetic moment, and large perpendicular magnetic anisotropy, and realizing two-dimensional quantum devices that can operate based on them.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a Ga-based van der Waals room-temperature ferromagnetic crystal material and a manufacturing method for solving the above-mentioned problems. According to the present invention, high-quality Ga-based van der Waals room-temperature ferromagnetic crystals of Fe 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d Te2 (c = -0.2 to 0.2, d = 0.01 to 0.5) can be manufactured. The Fe 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d Te2 (c = -0.2 to 0.2, d = 0.01 to 0.5) crystals all have a van der Waals structure, are easy to exfoliate up to a few layers (few layers), and the Curie temperatures are 330 - 367K and 320 - 345K respectively, which are higher than room temperature, and the saturation magnetic moments are 50 - 57.2 emu / g and 80 - 88.5 emu / g respectively. It has been realized that the perpendicular magnetic anisotropy of the Fe 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) single crystal is 3.25×10 5 ~4.79×10 5 J / m 3It can also reach two-dimensional Fe by mechanical peeling. 3-a Ga b Te2 (a=-0.3~0.1, b=0.8~1.2) and Fe 5-c GeGa d The thickness of Te2 (c=-0.2~0.2, d=0.01~0.5) nanosheets is on the nanometer scale, and their lateral size is on the micrometer scale, making them suitable for various current micro-nanofabrication technologies and usable for the fabrication of various multifunctional two-dimensional quantum devices. Furthermore, the method for producing the Ga-based van der Waals room-temperature ferromagnetic crystal material of the present invention is simple, low-cost, and has good process stability. The present invention is expected to contribute to the development and practical application of various multifunctional two-dimensional quantum devices based on Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystals.

[0005] From a first aspect of the present invention, a Ga-based van der Waals ferromagnetic crystalline material is provided, wherein the ferromagnetic crystalline material is Fe 3-a Ga b A ferromagnetic crystalline material having Te2, a=-0.3~0.1, b=0.8~1.2, or the ferromagnetic crystalline material being Fe 5-c GeGa d A ferromagnetic crystalline material having Te2, c=-0.2~0.2, and d=0.01~0.5, and the aforementioned Fe 3-a Ga b Fe in Te2 ferromagnetic crystal 3-a Ga b Te2 compound and the Fe 5-c GeGa d Fe in Te2 ferromagnetic crystal 5-c GeGa d All Te2 compounds contain iron atoms with a valency of 0, and the aforementioned Fe 3-a Ga b Te2 ferromagnetic crystal and the Fe 5-c GeGa d The Curie temperatures of the Te ferromagnetic crystals are 330-367K and 320-345K, respectively. 3-a Ga b Te2 ferromagnetic crystal and the Fe 5-c GeGa dTe2 ferromagnetic crystals exhibit magnetism below their respective Curie temperatures. Preferably, the Fe 3-a Ga b Te2 ferromagnetic crystal and Fe 5-c GeGa d The saturation magnetic moments of the Te2 ferromagnetic crystals are 50–57.2 emu / g and 80–88.5 emu / g, respectively. Another aspect of the present invention provides a method for producing a ferromagnetic crystal, comprising: step (1) uniformly and thoroughly mixing Fe powder, Ga blocks, and Te powder, wherein the sum of the amounts of substance of the Fe powder and Ga blocks is equal to the amount of substance of the Te powder, and the amount of substance of the Fe powder is 40% to 60% of the sum of the amounts of substance of the Fe powder and Ga blocks; step (2) vacuuming a container containing the mixture obtained in step (1); and heating the mixture at a heating temperature of 950 to 1050°C, cooling after heating, and cooling at a rate of 0.5 to 1.5°C / h during the crystal growth process, Fe 3-a Ga b The step of obtaining a Te2 ferromagnetic crystal includes step (3), wherein a = -0.3 to 0.1 and b = 0.8 to 1.2. Preferably, the heating time is 24 to 48 hours. Preferably, the cooling process involves first rapidly cooling to 880°C at a rate of 70-170°C / h, then slowly cooling to 780°C at a rate of 0.5-1.5°C / h, and finally allowing it to cool naturally. From another aspect of the present invention, a method for producing a ferromagnetic crystal is provided, comprising: step (1) uniformly and thoroughly mixing Fe powder, Ge powder, Ga block, Te powder and I2 particles, wherein the ratio of the amount of Fe powder, the sum of the amounts of Ge powder and Ga block, and the amount of Te powder is 4:1:2, and the amount of Ge powder is 40% to 60% of the sum of the amounts of Ge powder and Ga block; step (2) vacuuming a container containing the mixture obtained in step (1); and placing the portion of the container containing the mixture in the high-temperature raw material zone of a double-temperature zone tubular furnace, and placing the portion of the container not containing the mixture in the low-temperature crystallization zone of a double-temperature zone tubular furnace, wherein the temperature of the high-temperature raw material zone is 950 to 1050°C, the temperature of the low-temperature crystallization zone is 600 to 700°C, and the I2 particles are used as a transport agent to transport the mixture to the low-temperature crystallization zone and react with Fe 5-c GeGa d The step of obtaining a Te2 magnetic crystal includes step (3) where c = -0.2 to 0.2 and d = 0.01 to 0.5. Preferably, in step (3), the reaction time is 168h to 330h. Preferably, the mass of I2 particles relative to the container volume is 3 to 9 mg / cm³. 3 . Another aspect of the present invention provides the application of the Ga-based van der Waals magnetic crystal material in two-dimensional quantum devices. Preferably, the two-dimensional quantum device is an anomalous Hall device or an electrically controlled magnetic device. [Effects of the Invention]

[0006] Compared to existing technologies, the technical solution of the present invention has the following main technical advantages.

[0007] (1) Fe grown by slowly cooling to near the crystallization temperature using the self-flux method 3-a Ga bBecause the Te2 (a=-0.3~0.1, b=0.8~1.2) block single crystals have high purity and are easy to exfoliate, a few layers (a small number of layers) of two-dimensional nanosheets can be obtained. Their size is suitable for micro- and nanofabrication techniques such as photolithography, making them suitable for the fabrication of various multifunctional two-dimensional quantum devices.

[0008] (2) Using the chemical vapor transport method, iodine is used as the transport agent to grow Fe in the low-temperature crystal zone of the quartz ampoule bottle at a constant temperature. 5-c GeGa d Because Te2 (c=-0.2~0.2, d=0.01~0.5) single crystals have high purity and are easy to exfoliate, a few layers (a small number of layers) of two-dimensional nanosheets can be obtained. Their size is suitable for micro- and nanofabrication techniques such as photolithography, making them suitable for the fabrication of various multifunctional two-dimensional quantum devices.

[0009] (3) Fe 3-a Ga b In the case of Te2 (a=-0.3~0.1, b=0.8~1.2), a sufficiently large amount of Ga and Te is required as flux to dissolve the high-melting-point Fe, so the ratio of raw material usage described in the claims is adopted. In this case, since Ga plays a more important role, the relationship between the molar amounts of Fe and Ga in the raw materials is further defined. Fe 5-c GeGa d In the case of Te2 (c=-0.2~0.2, d=0.01~0.5), the efficiency of iodine in transporting the four elements involved in the compound differs, so the ratio of raw material usage described in the claim is adopted. For example, compared to Ge, Ga is difficult to transport, so the compound Fe 5-c GeGa d Even when the amount of Ga in Te2 (c=-0.2~0.2, d=0.01~0.5) is much less than that of Ge, it is still necessary to add an excess of Ga to the raw material.

[0010] (4) Ga-based van der Waals room temperature ferromagnetic crystal Fe produced by the present invention 3-a Ga b Te2 (a=-0.3~0.1, b=0.8~1.2) and Fe 5-cGeGa d The Curie temperatures of Te2 (c=-0.2~0.2, d=0.01~0.5) single crystals are 330~367K and 320~345K, respectively. This superroom-temperature ferromagnetism originates from the zero-valent iron atoms present in both materials, and Fe 3-a Ga b Fe in Te2 (a=-0.3~0.1, b=0.8~1.2) magnetic crystal 3-a Ga b In Te2 (a=-0.3~0.1, b=0.8~1.2) compounds, one iron atom is 0 valence, and the theoretical Curie temperature of a 0 valence iron atom (i.e., elemental iron) reaches 1043 K. However, in compounds, Fe 3-a Ga b Te2 (a=-0.3~0.1, b=0.8~1.2) and Fe 5-c GeGa d The Curie temperature decreases due to the difference in crystal structure between the Te2 (c=-0.2~0.2, d=0.01~0.5) single crystal and the elemental iron, but it is still higher than 300K, and higher than most known van der Waals magnetic crystals.

[0011] (5) All Ga-based van der Waals room-temperature ferromagnetic crystals produced by the present invention have a large saturation magnetic moment. Specifically, Fe 3-a Ga b The saturation magnetic moment of a Te2 (a=-0.3~0.1, b=0.8~1.2) single crystal is 50~57.2 emu / g, and Fe 5-c GeGa d The saturation magnetic moment of Te2 (c=-0.2~0.2, d=0.01~0.5) single crystals is 80~88.5 emu / g, which is higher than most known two-dimensional van der Waals magnetic crystals.

[0012] (6) Ga-based van der Waals room temperature ferromagnetic crystal Fe produced by the present invention 3-a Ga b Te2 (a=-0.3~0.1, b=0.8~1.2) exhibits large perpendicular magnetic anisotropy, with a perpendicular magnetic anisotropy of 3.25 × 10⁻¹⁰ at 300 K. 5 ~4.79 × 10 5 J / m 3This is high, higher than most widely used ferromagnetic thin-film materials.

[0013] (7) Fe 3-a Ga b Te2 (a=-0.3~0.1, b=0.8~1.2) and Fe 5-c GeGa d The two-dimensional nanosheets obtained by mechanically exfoliating Te2 (c=-0.2~0.2, d=0.01~0.5) single crystals are on a micrometer scale in size and nanometer scale in thickness. They are suitable for micro- and nanofabrication processes such as photolithography of materials, and can be used to realize anomalous Hall elements and electrically controlled magnetic elements, with a wide range of applications expected in the field of two-dimensional quantum devices. [Brief explanation of the drawing]

[0014] [Figure 1] This is the X-ray diffraction pattern of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. [Figure 2] This is the X-ray diffraction pattern of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe5GeGa0.1Te2 single crystal in Embodiment 4. [Figure 3] This is an energy spectrum elemental distribution diagram of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 nanosheet in Embodiment 1. [Figure 4] This is an energy spectrum elemental distribution diagram of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe5GeGa0.1Te2 nanosheet in Embodiment 4. [Figure 5] These are the spontaneous magnetization curve, out-of-plane magnetic field, and hysteresis curves at different temperatures for a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. [Figure 6] These are the spontaneous magnetization curve, out-of-plane magnetic field, and hysteresis curves at different temperatures for a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe5GeGa0.1Te2 single crystal in Embodiment 4. [Figure 7]This figure shows the anomalous Hall element and the super-room temperature anomalous Hall effect of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 nanosheet in Embodiment 1. [Figure 8] This figure shows the anomalous Hall element and the super-room temperature anomalous Hall effect of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe5GeGa0.1Te2 nanosheet in Embodiment 4. [Figure 9] This figure shows the hysteresis curve at an in-plane magnetic field of 300K for a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. [Figure 10] This is an electrically controlled magnetization curve diagram of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. [Modes for carrying out the invention]

[0015] To further clarify the object, technical solutions, and advantages of the present invention, the invention will be described in more detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are used solely for illustrative purposes and are not intended to limit the invention. Furthermore, the technical features of the various embodiments of the invention described below can be combined with each other, insofar as they do not conflict with each other.

[0016] This invention presents a Ga-based van der Waals room-temperature ferromagnetic crystalline material and a method for producing the same, the method for producing the material is as follows.

[0017] Fe 3-a Ga b Regarding Te2 (a=-0.3~0.1, b=0.8~1.2) 1) Step 1: Place Fe powder (99.99% purity), Ga block (99.999% purity), and Te powder (99.999% purity) in a specific molar ratio at the bottom of a quartz ampoule bottle. The specific molar ratio means that the sum of the amounts of substance of Fe powder and Ga block is equal to the amount of substance of Te powder. In this embodiment, the amount of substance of Fe powder accounts for 40% to 60% of the sum of the amounts of substance of Fe powder and Ga block.

[0018] 2) Step 2: Vacuum seal the ampoule bottle.

[0019] 3) Step 3: Place the ampoule bottle in the muffle furnace and raise the temperature to 950-1050°C within 1-5 hours, maintain the temperature for 1-2 days, then rapidly cool to 880°C, and slowly cool to 780°C at a rate of 0.5-1.5°C / h. After that, the program (execution step) is finished, and the ampoule bottle is allowed to cool naturally to room temperature in the muffle furnace.

[0020] Fe 5-c GeGa d Regarding Te2 (c=-0.2 to 0.2, d=0.01 to 0.5) 1) Step 1: Place a specific molar ratio of Fe powder (99.99% purity), Ge powder (99.999% purity), Ga block (99.999% purity), Te powder (99.999% purity), and a specific mass of I2 particles (99.99% purity) at the bottom of a quartz ampoule bottle. The specific molar ratio means that the ratio of the amount of substance of the Fe powder, the sum of the amounts of substance of the Ge powder and Ga block, and the amount of substance of the Te powder is 4:1:2. In this embodiment, the amount of substance of the Ge powder accounts for 40% to 60% of the sum of the amounts of substance of the Ge powder and Ga block.

[0021] 2) Step 2: Vacuum seal the ampoule bottle. 3) Step 3: Place the ampoule bottle in a double-temperature zone tubular furnace (a tubular furnace with two heating zones). The raw material end is the high-temperature raw material zone (high-temperature zone), and the other end is the low-temperature crystallization zone (low-temperature zone). Within 1 to 5 hours, heat the high-temperature zone and the low-temperature zone to 950 to 1050 °C and 600 to 700 °C, respectively. After maintaining the temperature for 1 to 2 weeks, let it cool naturally to room temperature.

[0022] In a certain embodiment, the size of the Ga block is 1 to 10 mm, and the volume is 0.1 to 0.5 cm 3 . The range of the I2 particle diameter is 1 to 3 mm, and the mass of the I2 particles relative to the volume of the container is 3 to 9 mg / cm 3 . The size of the Fe, Ge, Te powders is 100 to 300 mesh.

[0023] In a certain embodiment, the process of evacuating and sealing the quartz tube (vacuum sealing process) is as follows. Use a mechanical pump to evacuate to below 1 Pa, wash three times with argon gas with a purity of 99.999% to remove oxygen in the quartz tube, and finally, seal the glass tube with an oxyhydrogen flame.

[0024] In a certain embodiment, Fe 3-a Ga b The tube diameter of the quartz ampoule bottle for growing Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) is 2 cm, and the length is 10 cm. Fe 5-c GeGa d The tube diameter of the quartz ampoule bottle for growing Te2 (c = -0.2 to 0.2, d = 0.01 to 0.5) is 2 to 5 cm, and the length is 40 cm.

[0025] In a certain embodiment, the sizes of the crystal materials of the Fe 3-a Ga b Te2 (a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d Te (c = -0.2 to 0.2, d = 0.01 to 0.5) are 2 to 3 × 1 to 2 × 0.1 to 0.5 mm and 6 × 4 × 0.1 to 0.5 mm, respectively.

[0026] The Fe produced by the Ga-based van der Waals room-temperature ferromagnetic crystal material of the present invention and its manufacturing method 3-a Ga b Te2(a = -0.3 to 0.1, b = 0.8 to 1.2) and Fe 5-c GeGa d The strong crystal materials of Te2(c = -0.2 to 0.2, d = 0.01 to 0.5) are all high-quality room-temperature ferromagnetic compounds. Because they have a van der Waals structure, they are easy to mechanically exfoliate, exhibit a silver-white color, and can be exfoliated into two-dimensional nanocrystals with a flat surface and relatively thin thickness. Therefore, the present invention can be used for the fabrication of multifunctional two-dimensional quantum devices, and all of the above materials are single crystals.

[0027] The Ga-based van der Waals room-temperature ferromagnetic crystal material and the manufacturing method of the present invention will be described in detail below with reference to the following specific embodiments and drawings. Embodiment 1 1) Weigh high-purity Fe powder, Ga block and Te powder in a molar ratio of 1:1:2, put them at the bottom of a quartz ampoule bottle, and then evacuate and seal it.

[0028] 2) Place the sealed ampoule bottle in a muffler furnace. Heat it up to 1000 °C over 1 hour, keep it warm for 1 day, quickly cool it to 880 °C at a rate of 100 °C / h, and slowly cool it to 780 °C at a rate of 1 °C / h. Then, end the process and let the ampoule bottle cool naturally in the furnace to room temperature to obtain a single crystal of Fe3GaTe2. Embodiment 2 1) Weigh high-purity Fe powder, Ga block and Te powder in a molar ratio of 0.8:1.2:2, put them at the bottom of a quartz ampoule bottle, and then evacuate and seal it.

[0029] 2) Place the sealed ampoule bottle in a muffler furnace. Heat it up to 1000 °C over 1 hour, keep it warm for 1 day, quickly cool it to 880 °C at a rate of 100 °C / h, and slowly cool it to 780 °C at a rate of 1 °C / h. Then, end the process and let the ampoule bottle cool naturally in the furnace to room temperature to obtain Fe 2.9 Ga 1.2Obtain a single crystal of Te2. Embodiment 3 1) Weigh high-purity Fe powder, Ga blocks, and Te powder in a molar ratio of 1.2:0.8:2, place them at the bottom of a quartz ampoule, and then vacuum seal it.

[0030] 2) Place the sealed ampoule bottle in the muffle furnace. Heat to 1000°C over 1 hour, maintain temperature for 1 day, rapidly cool to 880°C at a rate of 100°C / h, and then slowly cool to 780°C at a rate of 1°C / h. After that, terminate the process and allow the ampoule bottle to naturally cool to room temperature in the furnace. 3.3 Ga 0.8 Obtain a single crystal of Te2. Embodiment 4 1) Weigh high-purity Fe powder, Ge powder, Ga blocks, Te powder, and 0.3g I2 particles in a molar ratio of 8:1:1:4, place them at the bottom of a quartz ampoule, and then vacuum seal it.

[0031] 2) Place the sealed ampoule in a double-temperature zone tubular furnace, with the raw material end in the high-temperature raw material zone (high-temperature zone) and the other end in the low-temperature crystallization zone (low-temperature zone). Within one hour, heat the high-temperature and low-temperature zones to 1000°C and 650°C respectively, maintain the temperature for two weeks, then allow to cool naturally to room temperature, and in the crystallization zone, infuse Fe5GeGa 0.1 Obtain a single crystal of Te2. Embodiment 5 1) Weigh high-purity Fe powder, Ge powder, Ga blocks, Te powder, and 0.3g I2 particles in a molar ratio of 8:1.2:0.8:4, place them at the bottom of a quartz ampoule, and then vacuum seal it.

[0032] 2) Place the sealed ampoule in a double-temperature zone tubular furnace, with one end being the high-temperature raw material zone (high-temperature zone) and the other end being the low-temperature crystallization zone (low-temperature zone). Within one hour, heat the high-temperature and low-temperature zones to 1000°C and 650°C respectively, maintain the temperature for two weeks, then allow to cool naturally to room temperature, and in the crystallization zone, Fe 5.2 GeGa 0.01 Obtain a single crystal of Te2. Embodiment 6 1) Weigh high-purity Fe powder, Ge powder, Ga blocks, Te powder, and 0.3g I2 particles in a molar ratio of 8:0.8:1.2:4, place them at the bottom of a quartz ampoule, and then vacuum seal it.

[0033] 2) Place the sealed ampoule in a double-temperature zone tubular furnace, with one end being the high-temperature raw material zone (high-temperature zone) and the other end being the low-temperature crystallization zone (low-temperature zone). Within one hour, heat the high-temperature and low-temperature zones to 1000°C and 650°C respectively, maintain the temperature for two weeks, then allow to cool naturally to room temperature, and in the crystallization zone, Fe 4.8 GeGa 0.5 Obtain a single crystal of Te2.

[0034] Figure 1 shows the X-ray diffraction pattern of a Fe3GaTe2 single crystal. Compared to the theoretical X-ray diffraction pattern, the equally spaced diffraction peaks in the Fe3GaTe2 single crystal X-ray diffraction pattern correspond to the (001) crystal plane, and no impurity peaks are observed. This indicates that the synthesized Fe3GaTe2 single crystal has high crystal quality and strict growth orientation. Figure 2 shows Fe5GeGa 0.1 This is the X-ray diffraction pattern of a Te2 single crystal, and when compared to the theoretical X-ray diffraction pattern, Fe5GeGa 0.1 The equally spaced diffraction peaks in the X-ray diffraction pattern of the Te2 single crystal correspond to the (001) crystal plane, and no impurity peaks are observed. This is because the synthesized Fe5GeGa 0.1 This shows that Te2 single crystals possess high crystal quality and precise growth orientation. Figure 3 is the energy spectrum elemental distribution diagram of Fe3GaTe2 nanosheets. Energy spectral analysis reveals that the three elements Fe, Ga, and Te are uniformly distributed in Fe3GaTe2. Figure 4 shows Fe5GeGa 0.1 This is an energy spectrum elemental distribution map of Te2 nanosheets. Energy spectral analysis revealed that the four elements Fe, Ge, Ga, and Te are represented as Fe5GeGa. 0.1It can be seen that it is uniformly distributed in Te2. Figure 5 shows the spontaneous magnetization curve, out-of-plane magnetic field, and hysteresis curve at different temperatures of the Fe3GaTe2 single crystal, demonstrating that the Fe3GaTe2 single crystal has intrinsic superroom temperature ferromagnetism and a large saturation magnetic moment. Figure 6 shows Fe5GeGa 0.1 The spontaneous magnetization curve, out-of-plane magnetic field, and hysteresis curves of a Te2 single crystal at different temperatures are shown, as well as the Fe5GeGa curve. 0.1 This shows that the Te2 single crystal possesses intrinsic superroom temperature ferromagnetism and a large saturation magnetic moment. Figure 7 shows an anomalous Hall element and superroom temperature anomalous Hall effect of Fe3GaTe2 nanosheets, demonstrating the easy exfoliation properties, intrinsic superroom temperature ferromagnetism, and potential applications for two-dimensional quantum devices of the Fe3GaTe2 single crystal. Figure 8 shows Fe5GeGa 0.1 The Te2 nanosheet exhibits an anomalous Hall element and a super-room temperature anomalous Hall effect, and Fe5GeGa 0.1 This demonstrates the easy exfoliation properties of Te2 single crystals, their inherent superroom-temperature ferromagnetism, and potential applications in two-dimensional quantum devices. Figure 9 shows the in-plane magnetic field and hysteresis curve at 300 K for a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. This figure shows that the perpendicular magnetic anisotropy of Fe3GaTe2 at 300 K is 4.79 × 10⁻¹⁰. 5 J / m 3 It can be calculated that it reaches this value. Figure 10 is an electrically controlled magnetization curve diagram of a Ga-based two-dimensional van der Waals room-temperature ferromagnetic crystal Fe3GaTe2 single crystal in Embodiment 1. This shows that the current flowing through the device has a large tuning effect on the Hall resistance of the sample, indicating potential applications in the field of two-dimensional quantum devices.

[0035] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention and does not limit it, and any modifications, equivalent substitutions, and improvements made within the spirit and principles are all within the scope of protection of the present invention.

Claims

1. A Ga-based van der Waals magnetic crystal material, wherein the magnetic crystal material is Fe ３－ａ Ga ｂ Te ２ A magnetic crystal material having a = -0.3 to 0.1 and b = 0.8 to 1.2, or the magnetic crystal material being Fe ５－ｃ GeGa ｄ Te ２ A magnetic crystal material having c = -0.2 to 0.2 and d = 0.01 to 0.

5. The aforementioned Fe ３－ａ Ga ｂ Te ２ Fe of magnetic crystal ３－ａ Ga ｂ Te ２ compound and the aforementioned Fe ５－ｃ GeGa ｄ Te ２ Fe of magnetic crystal ５－ｃ GeGa ｄ Te ２ All of the compounds contain iron atoms with a valence of 0, The Fe ３－ａ Ga ｂ Te ２ Magnetic crystal and the Fe ５－ｃ GeGa ｄ Te ２ The Curie temperatures of the magnetic crystals are 330-367K and 320-345K, respectively, and the Fe ３－ａ Ga ｂ Te ２ Magnetic crystal and the Fe ５－ｃ GeGa ｄ Te ２ A Ga-based van der Waals magnetic crystal material characterized by the magnetic crystals exhibiting magnetism below their respective Curie temperatures.

2. The Fe ３－ａ Ga ｂ Te ２ Magnetic crystals and Fe ５－ｃ GeGa ｄ Te ２ The Ga-based van der Waals magnetic crystal material according to claim 1, characterized in that the saturation magnetic moment of the magnetic crystal is 50 to 57.2 emu / g and 80 to 88.5 emu / g, respectively.

3. A method for manufacturing magnetic crystals, Step (1) involves thoroughly mixing Fe powder, Ga block, and Te powder, such that the sum of the amounts of Fe powder and Ga block is equal to the amount of Te powder, and the amount of Fe powder is 40% to 60% of the sum of the amounts of Fe powder and Ga block. Step (2) involves vacuuming the container holding the mixture obtained in step (1), The mixture is heated to a heating temperature of 950 to 1050°C, and after heating, the temperature is lowered at a rate of 0.5 to 1.5°C / h during the crystal growth process, and Fe ３－ａ Ga ｂ Te ２ A method for producing a magnetic crystal, characterized by comprising step (3), a step of obtaining a magnetic crystal, wherein a = -0.3 to 0.1 and b = 0.8 to 1.

2.

4. The method for producing magnetic crystals according to claim 3, characterized in that the heating time is 24 hours to 48 hours.

5. The method for producing a magnetic crystal according to claim 3, characterized in that the cooling is first rapidly cooled to 880°C at a rate of 70 to 170°C / h, then slowly cooled to 780°C at a rate of 0.5 to 1.5°C / h, and then allowed to cool naturally.

6. A method for manufacturing magnetic crystals, Fe powder, Ge powder, Ga block, Te powder and I ２ Step (1) involves thoroughly mixing the particles, where the ratio of the amount of Fe powder, the sum of the amounts of Ge powder and Ga block, and the amount of Te powder is 4:1:2, and the amount of Ge powder is 40% to 60% of the sum of the amounts of Ge powder and Ga block. Step (2) involves vacuuming the container holding the mixture obtained in step (1), The portion of the container containing the mixture is placed in the high-temperature raw material zone within the double-temperature zone tubular furnace, and the portion of the container not containing the mixture is placed in the low-temperature crystallization zone within the double-temperature zone tubular furnace, the temperature of the high-temperature raw material zone is 950 to 1050°C, and the temperature of the low-temperature crystallization zone is 600 to 700°C, and the I ２ The particles are used as a transport agent to transport the mixture to a low-temperature crystallization zone where it reacts with Fe. ５－ｃ GeGa ｄ Te ２ A method for producing a magnetic crystal, characterized by comprising the step (3) of obtaining a magnetic crystal, wherein c = -0.2 to 0.2 and d = 0.01 to 0.

5.

7. The method for producing a magnetic crystal according to claim 6, characterized in that in step (3), the reaction time is 168 h to 330 h.

8. I relative to the volume of the container ２ The particle mass is 3–9 mg / cm³. ３ The method for producing magnetic crystals according to pharmaceutically acceptable 6.

9. A two-dimensional quantum device using the Ga-based van der Waals magnetic crystal material described in claim 1 or claim 2.

10. The two-dimensional quantum device according to claim 9, characterized in that the two-dimensional quantum device is an anomalous Hall device or an electrically controlled magnetic device.

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