A two-dimensional magnetic material device and its preparation method and control method

Abstract

The present invention discloses a two-dimensional magnetic material device and a preparation method and a control method thereof, wherein the control method comprises: covering the surface of the two-dimensional magnetic material with an ionic liquid, making the ionic liquid contact a gate, a source electrode, a drain electrode and the two-dimensional magnetic material, and continuously applying a current from the gate to the source electrode and to the drain electrode to complete the control of the two-dimensional magnetic material device. The two-dimensional magnetic material device and the preparation method and the control method provided by the present invention intercalate the two-dimensional magnetic material device with an ionic liquid containing cationic molecular chains of different lengths to achieve the control of the two-dimensional material magnetic device, which greatly improves the flexibility of controlling the two-dimensional magnetic material, and can change the coercive field, magnetic anisotropy and carrier concentration of the two-dimensional magnetic material.

Description

Technical Field

[0001] The present invention relates to the technical field of two-dimensional material devices, and in particular to a two-dimensional magnetic material device and a preparation method and a control method thereof. Background Art

[0002] Since the discovery of single-layer graphene in 2004, two-dimensional materials have received more and more attention and research. Due to their good electrical, thermal, optical and mechanical properties, they have become a major research hotspot in the scientific community in recent years. As a branch of two-dimensional materials, two-dimensional magnetic materials have special properties such as magnetic anisotropy and single-layer magnetic order. Their magnetic properties can also be regulated by various fields, making them have rich physical properties and potential application value. This makes it very necessary to study the regulation of two-dimensional magnetic materials.

[0003] There are methods such as electronic engineering, mechanical engineering, and interface engineering to control two-dimensional magnetic materials. However, the complexity of these methods, the high requirements for the interface, and the limitations of the control effects limit their development and application. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a two-dimensional magnetic material device and a preparation method and a control method thereof. By selecting ionic liquids containing cationic molecular chains of different lengths to intercalate the two-dimensional magnetic material device, the control of the two-dimensional material magnetic device is achieved, which greatly improves the flexibility of controlling the two-dimensional magnetic material and can change the coercive field, magnetic anisotropy and carrier concentration of the two-dimensional magnetic material.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for regulating a two-dimensional magnetic material device, wherein the two-dimensional magnetic material device comprises a substrate, a source electrode, a drain electrode, a gate and a two-dimensional magnetic material;

[0007] Wherein, the source electrode, the drain electrode and the gate are all connected to the substrate, and the two-dimensional magnetic material covers between the source electrode and the drain electrode;

[0008] The control method includes: covering the surface of the two-dimensional magnetic material device with ionic liquid, making the ionic liquid contact the gate, source electrode, drain electrode and two-dimensional magnetic material, heating the two-dimensional magnetic material device and continuously applying current from the gate to the source electrode and to the drain electrode to complete the control of the two-dimensional magnetic material device.

[0009] Furthermore, the current continuously applied from the gate to the source electrode and to the drain electrode has a current size of 100nA-2mA and a duration of 30min-120min;

[0010] And / or, the temperature of heating the two-dimensional magnetic material device is 80°C-120°C.

[0011] Furthermore, the cationic molecular chain contained in the ionic liquid is represented by [C n MIm] + , where n≥1;

[0012] And / or, the cationic molecular chain has a length of 2-20Å and a width of 1-2Å.

[0013] Further, the ionic liquid is selected from one of 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt, 1-hexyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt and 1-dodecyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt;

[0014] The two-dimensional magnetic material includes one of Fe3GaTe2 and Fe3GeTe2.

[0015] In a second aspect, the present invention provides a two-dimensional magnetic material device, which is regulated by the method of the two-dimensional magnetic material device provided by the present invention.

[0016] In a third aspect, the present invention provides a method for preparing the two-dimensional magnetic material device, comprising:

[0017] A source electrode, a drain electrode and a gate are prepared on a substrate according to a preset electrode pattern;

[0018] The two-dimensional magnetic material is attached to the tape and peeled off by repeatedly attaching and tearing the tape;

[0019] The peeled two-dimensional magnetic material is transferred to the substrate on which the source electrode, drain electrode and gate electrode are prepared, so that the two-dimensional magnetic material is in contact with the source electrode and drain electrode to obtain a two-dimensional magnetic material device.

[0020] Furthermore, the step of preparing a source electrode, a drain electrode and a gate on a substrate according to a preset electrode pattern includes:

[0021] Coating a photoresist on a substrate, then sequentially exposing, developing, fixing and drying the substrate coated with the photoresist according to a preset electrode pattern, so as to transfer the preset electrode pattern to the substrate;

[0022] A titanium layer is evaporated on the substrate after the electrode pattern is transferred by electron beam evaporation technology, and then a gold layer is evaporated by thermal evaporation technology;

[0023] The excess titanium layer and gold layer on the evaporated substrate are stripped off to obtain a substrate on which a source electrode, a drain electrode and a gate electrode are prepared.

[0024] Furthermore, the coating of the photoresist on the substrate specifically includes: adsorbing the substrate on a coating machine and spin-coating the photoresist multiple times, and drying the substrate at a temperature of 120° C. after each spin coating;

[0025] And / or, the photoresist is selected from one of polymethyl methacrylate and methyl methacrylate;

[0026] And / or, the exposure, development, fixing and drying are performed in sequence, wherein the development time is 30-40s, and the fixing time is 10-15s.

[0027] Furthermore, the thickness of the titanium layer is 4-6 nm, and the thickness of the gold layer is 18-22 nm;

[0028] And / or, the speed of evaporating a titanium layer is 0.1-0.2Å / s, and the speed of evaporating a gold layer is 0.25-0.3Å / s.

[0029] Furthermore, before preparing the source electrode, the drain electrode and the gate electrode on the substrate according to the preset electrode pattern, the substrate needs to be pretreated, specifically including: ultrasonically cleaning the substrate in acetone, ethanol and deionized water in turn, and drying with nitrogen after cleaning;

[0030] And / or, the exfoliated two-dimensional magnetic material is transferred to a substrate on which a source electrode, a drain electrode and a gate are prepared, including transferring the exfoliated two-dimensional magnetic material to polydimethylsiloxane to obtain a composite film, transferring the composite film to a substrate on which a source electrode, a drain electrode and a gate are prepared, and making the two-dimensional magnetic material contact with the source electrode and the drain electrode, and then removing the polydimethylsiloxane;

[0031] And / or, the operation of transferring the peeled two-dimensional magnetic material to the substrate on which the source electrode, the drain electrode and the gate have been prepared, so that the two-dimensional magnetic material is in contact with the source electrode and the drain electrode, and obtaining the two-dimensional magnetic material device is carried out in a glove box, and the water content of the glove box is less than 0.1ppm, and the oxygen content is less than 0.1ppm.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The control method of the two-dimensional magnetic material device provided by the present invention can control the anomalous Hall resistance of the two-dimensional magnetic material device by intercalating the two-dimensional magnetic material device with ionic liquid. 12After MIm]TFSI intercalation, the anomalous Hall resistance of Fe3GaTe2 devices increased by about 75%, 200%, and 420% respectively at 4K compared with that before intercalation. With the increase of the length of the cation molecular chain, the regulation effect becomes more and more obvious. This method can overcome the disadvantage that the traditional solid gate dielectric electric field regulation cannot be regulated due to the high carrier concentration of two-dimensional magnetic metals, and has a better regulation effect. At the same time, the regulation effect will also change with the type and chain length of the cations, increasing the flexibility of ionic liquid regulation. At the same time, the achieved regulation effect is non-volatile. The two-dimensional magnetic material device can maintain the properties after regulation, the regulation is more stable, and the working current is small. The current of 10mA or even lower can drive the device to work, with low power consumption, and has the potential to be integrated into magnetic devices.

[0034] The control method of the two-dimensional magnetic material device provided by the present invention can also realize the control of other magnetic and electrical properties, including coercive field, carrier concentration, magnetic anisotropy constant and longitudinal resistance, by using ionic liquid to intercalate the two-dimensional magnetic material device. Among them, the longitudinal resistance of the two-dimensional magnetic material device after [C2MIm]TFSI intercalation at all temperature points increases, and the coercive field, carrier concentration and magnetic anisotropy constant decrease.

[0035] The two-dimensional magnetic material device and preparation method thereof provided by the present invention make the device preparation process relatively simple by setting a three-layer device structure, and adopt a process flow of first making a metal electrode and then transferring the sample, which effectively avoids the negative impact of electron beam colloid, organic liquid and deionized water on the sample, and also greatly improves the interface quality. At the same time, it improves the fault tolerance rate in the device preparation process, making the preparation easier, more convenient and feasible.

[0036] The preparation method of the two-dimensional magnetic material device provided by the present invention adopts a mechanical stripping method to strip the two-dimensional magnetic material, and the obtained thin slices are of high quality, so that extremely high-quality heterojunction interfaces can be constructed. There will be no defects, vacancies, etc. that affect the interface quality, as in thin films obtained by methods such as chemical vapor deposition and physical vapor deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of anions and cations in an ionic liquid provided in an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of the structure of a two-dimensional magnetic material device provided by an embodiment of the present invention;

[0039] Figure 3 An optical imaging diagram of a two-dimensional magnetic material device provided by an embodiment of the present invention;

[0040] Figure 4 A schematic diagram of ionic liquid intercalation regulation of a two-dimensional magnetic material device provided in an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of abnormal Hall test results obtained before and after different ionic liquid intercalation of a two-dimensional magnetic material device provided by an embodiment of the present invention;

[0042] Figure 6 A schematic diagram of the changes in the coercive field, carrier concentration, magnetic anisotropy constant and longitudinal resistance of a two-dimensional magnetic material device provided in an embodiment of the present invention before and after [C2MIm]TFSI intercalation;

[0043] Figure 7 Schematic diagram of the changes in coercive field, carrier concentration, magnetic anisotropy constant and longitudinal resistance of a two-dimensional magnetic material device provided in an embodiment of the present invention before and after [C2MIm]TFSI intercalation.

[0044] Figure 2 , Figure 4 Middle: 1. Si layer; 2. SiO2 layer; 3. Two-dimensional magnetic material; 4. Gate; 5. Source electrode; 6. Drain electrode; 7. Hall detection electrode; 8. Ionic liquid. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0046] Example 1

[0047] This embodiment provides a two-dimensional magnetic material device and a preparation method and a control method thereof.

[0048] The structure of the two-dimensional magnetic material device provided in this embodiment is as follows Figure 2 As shown, it includes a substrate, a source electrode 5, a drain electrode 6, a gate 4 and a two-dimensional magnetic material 3. The source electrode 5, the drain electrode 6 and the gate 4 are all connected to the substrate, and the two-dimensional magnetic material 3 is covered between the source electrode 5 and the drain electrode 6. In this embodiment, a Hall detection electrode 7 is also provided on the two-dimensional magnetic material device for detecting abnormal Hall signals for testing. The Hall detection electrode 7 is prepared by the same method as the source electrode 5, the drain electrode 6 and the gate 4.

[0049] In this embodiment, the two-dimensional magnetic material is Fe3GaTe2, the substrate is a silicon wafer cut from a wafer, and the silicon wafer has a double-layer structure, with the lower layer being Si layer 1 and the upper layer being SiO2 layer 2.

[0050] The method for preparing the two-dimensional magnetic material device provided in this embodiment includes:

[0051] Step 1: Prepare the required source electrode, drain electrode and gate

[0052] Step 1.1: Cutting and cleaning silicon wafers

[0053] Take out the wafer from the silicon wafer box. The structure of the wafer is a layer of SiO2 and a layer of Si. The total thickness of the wafer is 500±15um, of which the thickness of SiO2 is 285nm. Use a diamond pen to cut a 0.8cm×0.8cm silicon wafer, put it into a beaker filled with acetone, and then put the beaker into an ultrasonic cleaner to ultrasonically clean the silicon wafer. The ultrasonic cleaning time is 2 minutes. After the cleaning is completed, use tweezers to clamp the silicon wafer out, and then put it into a beaker filled with ethanol and deionized water in turn. Repeat the cleaning process, then blow dry the silicon wafer with nitrogen and put it into a clean test tube. When using tweezers to clamp the silicon wafer, just clamp the edge, and be careful not to let the tweezers scratch the front of the silicon wafer. The purpose of using acetone is to use it as an organic solvent to dissolve organic pollutants such as grease on the silicon wafer, and the purpose of using ethanol is to remove the residual acetone. Finally, use deionized water to thoroughly clean the silicon wafer.

[0054] Step 1.2: Spin-coat photoresist

[0055] The cleaned silicon wafer is adsorbed on the coating machine and the photoresist is spin-coated. The types of photoresists are polymethyl methacrylate (EL6) and methyl methacrylate (A5). The photoresist should be dripped in the middle of the silicon wafer as much as possible during the coating process to ensure uniform coating. The speed of the coating machine is set in steps. The speed of the first step is 4000 rpm, the coating time is 33s, and the second step is 7000 rpm, and the coating time is 8s. After each coating process, the silicon wafer is placed on the heating platform for drying. The temperature is set to 120°C. The baking time is related to the thickness of the photoresist and is generally 2 minutes.

[0056] Step 1.3: Electron beam lithography

[0057] Place the silicon wafer with photoresist spin-coated into the chamber of the electron beam lithography machine (EBL) and evacuate the chamber to 10 -6 Below the Pa level, an electron beam is used to bombard a silicon wafer with a photoresist, and through this operation a silicon wafer with a preset electrode pattern is obtained.

[0058] Step 1.4: Development and Fixing

[0059] Place the exposed silicon wafer in the developer to remove the photoresist that has been denatured after electron beam exposure, and then place the silicon wafer in isopropyl alcohol to complete fixing. The development time is generally about 35 seconds, and the fixing time is about 10 seconds. Finally, use a nitrogen gun to blow dry the silicon wafer and place it in a clean test tube.

[0060] Step 1.5: Evaporation of metal

[0061] The exposed, developed and fixed silicon wafers were placed in the chamber of the electron beam evaporation (EBE) system and evacuated to 6×10 -4 After the temperature drops below Pa, 5nm of titanium (Ti) is first evaporated using an electron beam evaporation system, and then 20nm of gold (Au) is evaporated using a thermal evaporation system. The rate of titanium evaporation is controlled at 0.15Å / s, and the rate of gold evaporation is controlled at about 0.3Å / s to prevent uneven evaporation. After the evaporation is completed, wait for the chamber to cool to below 35°C and take out the silicon wafer.

[0062] Step 1.6: Stripping the Metal

[0063] After the evaporation is completed, the excess titanium layer and gold layer on the evaporated substrate are peeled off; the titanium layer and gold layer on the unexposed photoresist on the silicon wafer cannot be plated, which are the excess titanium layer and gold layer. The stripping method is: soak the silicon wafer in acetone solution, let it stand for about 10 minutes, and then use a rubber-tipped dropper to gently blow air to peel off the excess titanium layer and gold layer. The remaining parts are the required source electrode, drain electrode and gate.

[0064] Step 2: Transfer samples and make devices

[0065] To prevent oxidation of the material, all operations in step 2 must be completed in a glove box with a water content of less than 0.1 ppm and an oxygen content of less than 0.1 ppm.

[0066] Step 2.1: Stripping the Materials

[0067] Take the Fe3GaTe2 sample and stick it on the torn tape, fold the tape in the middle and tear it off, repeat the process 5-6 times, stick the PDMS film on the glass slide to the tape and peel it off to obtain the PDMS with Fe3GaTe2 flakes, and observe it under an optical microscope to find the Fe3GaTe2 sample with uniform thickness and a sample thickness of 40-60nm. The sample thickness can be judged by the color difference. The more transparent the color is, the closer it is to the substrate color, and the thinner it is. Generally, thicker samples are yellow-white and reflective.

[0068] Step 2.2: Transfer sample

[0069] A silicon wafer with a pre-prepared source electrode, drain electrode and gate is placed on the sample stage in the transfer platform and fixed. Then a glass slide with polydimethylsiloxane (PDMS) stained with the Fe3GaTe2 sample is placed upside down on the electrodes to make the Fe3GaTe2 sample contact with the source electrode and the drain electrode, thereby transferring the Fe3GaTe2 sample to the substrate, removing the polydimethylsiloxane, and obtaining a two-dimensional magnetic material device.

[0070] In this embodiment, an ionic liquid is used to intercalate a two-dimensional magnetic material device to regulate the two-dimensional magnetic material device. The selected ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ([C2MIm]TFSI), and the cation of the ionic liquid is [C2MIm] + , with a length of 3.56 Å and a width of 1.33 Å. Before regulation, the two-dimensional magnetic material device must first be bonded to a printed circuit board.

[0071] The control method of the two-dimensional magnetic material device provided in this embodiment includes: dropping ionic liquid 8 on the surface of the two-dimensional magnetic material device, and the ionic liquid 8 needs to cover the source electrode 5, the drain electrode 6, the channel area between the source electrode 5 and the drain electrode 6, and the gate 4 of the two-dimensional magnetic material device; then placing the printed circuit board with the two-dimensional magnetic material device on a heating platform, heating it to 80°C and applying a constant current of 300nA, in the direction from the gate 4 to the source electrode 5 and to the drain electrode 6, for 30 minutes, driven by the current, the cations in the ionic liquid 8 enter the interlayer of the two-dimensional magnetic material, and the heating accelerates the rate of the intercalation reaction; after the intercalation is completed, the ionic liquid is washed away with acetone and ethanol in turn to complete the control of the two-dimensional magnetic material device.

[0072] Figure 4 A schematic diagram of ionic liquid intercalation regulation of a two-dimensional magnetic material device provided in an embodiment of the present invention.

[0073] Example 2

[0074] This embodiment provides a two-dimensional magnetic material device and a preparation method and a control method thereof, wherein the two-dimensional magnetic material device and the preparation method thereof provided in this embodiment are the same as those provided in Example 1. Different from Example 1, in this embodiment, the ionic liquid selected for the control of the two-dimensional magnetic material device is 1-hexyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt ([C6MIm]TFSI), and the cation of the ionic liquid is [C6MIm] + , with a length of 6.42 Å and a width of 1.33 Å.

[0075] Example 3

[0076] This embodiment provides a two-dimensional magnetic material device and a preparation method and a control method thereof, wherein the two-dimensional magnetic material device and the preparation method thereof provided in this embodiment are the same as those provided in Example 1. Different from Example 1, in this embodiment, the ionic liquid selected for the control of the two-dimensional magnetic material device is 1-dodecyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt ([C 12 MIm]TFSI), the cation of the ionic liquid is [C 12 MIm] +, with a length of 10.70 Å and a width of 1.33 Å.

[0077] Example 4

[0078] This embodiment provides a two-dimensional magnetic material device and a preparation method and a control method thereof. Different from Embodiment 1, in this embodiment, the two-dimensional magnetic material is Fe3GeTe2.

[0079] Transport tests were performed on the two-dimensional magnetic material devices provided in Examples 1 to 4, and the tests were performed once before and after the ionic liquid intercalation regulation. The instruments used for the transport tests were Keithley 6221 source meter, OE1022D DSP phase lock, low temperature transport test system and EM series electromagnet.

[0080] The test method of the transport test is: place the bonded printed circuit board with the two-dimensional magnetic material device into the cavity of the low-temperature transport test system, and lower the temperature in the cavity to the target temperature for an anomalous Hall test.

[0081] The structure diagram of the two-dimensional magnetic material device used in the test is as follows: Figure 2 As shown in the figure, the entire device uses a silicon wafer as a substrate, on which is a pair of source and drain electrodes. Two pairs of Hall detection electrodes are set between the source and drain electrodes to ensure that abnormal Hall signals are detected. There is also a gate on the substrate for applying a constant current between the gate and the source electrode and between the gate and the drain electrode. The gate is made larger to ensure that the gate will not be completely reacted during the intercalation process. When the two-dimensional magnetic material sample is transferred to the electrode, the source electrode, drain electrode and Hall detection electrode must be covered to ensure the detection of abnormal Hall signals and the normal progress of the intercalation process. Figure 3 (a), (b) and (c) are optical imaging images of the two-dimensional magnetic material devices provided in Examples 1 to 3, respectively.

[0082] Figure 1 A schematic diagram of the structure of anions and cations in an ionic liquid provided in an embodiment of the present invention, Figure 1 (a) is [C2MIm] + The structural diagram of Figure 1 (b) is [C6MIm] + The structural diagram of Figure 1 Where (c) is [C 12 MIm] + The structural diagram of Figure 1 (d) is [TFSI] - Schematic diagram of the structure.

[0083] Figure 5 The abnormal Hall test data diagram of the two-dimensional magnetic material device before and after intercalation provided in Examples 1 to 3, Figure 5 (a) is a graph of abnormal Hall test data of the two-dimensional magnetic material device before and after intercalation provided in Example 1; Figure 5 (b) is a graph of abnormal Hall test data of the two-dimensional magnetic material device before and after intercalation provided in Example 2; Figure 5 (c) is a graph showing abnormal Hall test data of the two-dimensional magnetic material device before and after intercalation provided in Example 3; Figure 5 (d) is the change rate of the anomalous Hall resistance of the two-dimensional magnetic material device provided by Examples 1 to 3 before and after intercalation at different temperature points, wherein the change rate is calculated according to the following formula:

[0084] Percent=( R xy-Inercalated - R xy-pristine ) / R xy-pristine 100%

[0085] In the formula, R xy-Inercalated is the anomalous Hall resistance value of the two-dimensional magnetic material device after intercalation, R xy-pristine is the anomalous Hall resistance value of the two-dimensional magnetic material device before intercalation, and Percent is the rate of change of the anomalous Hall resistance value.

[0086] from Figure 5 It can be clearly seen that the anomalous Hall resistance of the two-dimensional magnetic material devices provided in Examples 1 to 3 increases after ionic liquid intercalation, and at 4K, the anomalous Hall resistance of C2MIm[TFSI] increases by about 75% after intercalation; C6MIm[TFSI] increases by about 200% after intercalation; and C 12 MIm[TFSI] increased by about 420% after intercalation. Because the use of ionic liquid intercalation to regulate the two-dimensional magnetic material device will drive the cationic molecular chain to insert into the interlayer of the two-dimensional magnetic material, effectively regulate the interlayer spacing of the two-dimensional magnetic material, and simultaneously realize ion injection, thereby changing the magnetic mutual exchange interaction, carrier concentration and magnetic anisotropy of the two-dimensional magnetic material, and finally realize the regulation of the performance of the two-dimensional magnetic material device such as the coercive field and magnetic anisotropy constant. The results of regulating the two-dimensional magnetic material device provided in Example 1 are shown in FIG. Figure 6 As shown, Figure 6 (a) is a schematic diagram of the change in longitudinal resistance of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 6 (b) is a schematic diagram of the change in the coercive field of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 6(c) is a schematic diagram of the change in carrier concentration of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 6 (d) is a schematic diagram of the change of magnetic anisotropy constant of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 6 It can be seen that the longitudinal resistance of the two-dimensional magnetic material device after intercalation increases, and the coercive field, carrier concentration and magnetic anisotropy constant decrease. The results of regulating the two-dimensional magnetic material device provided in Example 4 are as follows: Figure 7 As shown, Figure 7 (a) is a schematic diagram of the change in longitudinal resistance of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 7 (b) is a schematic diagram of the change in the coercive field of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 7 (c) is a schematic diagram of the change in carrier concentration of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 7 (d) is a schematic diagram of the change of magnetic anisotropy constant of a two-dimensional magnetic material device before and after [C2MIm]TFSI intercalation. Figure 7 It can be obtained that the longitudinal resistance of the two-dimensional magnetic material device increases after intercalation, and the coercive field, carrier concentration and magnetic anisotropy constant decrease.

[0087] Obviously, for professionals in this field, after understanding the content and design principles of the present invention, it is possible to make various modifications and changes in form, details, types of two-dimensional magnetic materials, types of ionic liquids, etc. without departing from the principles and structures of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the present invention.

[0088] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0089] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0090] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for controlling a two-dimensional magnetic material device, characterized in that: The two-dimensional magnetic material device comprises a substrate, a source electrode, a drain electrode, a gate and a two-dimensional magnetic material; Wherein, the source electrode, the drain electrode and the gate are all connected to the substrate, and the two-dimensional magnetic material covers between the source electrode and the drain electrode; The control method comprises: covering the surface of the two-dimensional magnetic material device with ionic liquid, making the ionic liquid contact the gate, the source electrode, the drain electrode and the two-dimensional magnetic material, heating the two-dimensional magnetic material device and continuously applying current from the gate to the source electrode and the drain electrode to complete the control of the two-dimensional magnetic material device; The ionic liquid is selected from one of 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt, 1-hexyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt and 1-dodecyl-3-methylimidazolium bis-trifluoromethanesulfonyl imide salt; The two-dimensional magnetic material includes one of Fe3GaTe2 and Fe3GeTe2.

2. The method for controlling a two-dimensional magnetic material device according to claim 1, characterized in that: The current continuously applied from the gate to the source electrode and the drain electrode is 100nA-2mA, and the duration is 30min-120min; And / or, the temperature of heating the two-dimensional magnetic material device is 80°C-120°C.

3. A two-dimensional magnetic material device, characterized in that: The two-dimensional magnetic material device is regulated by the regulation method of the two-dimensional magnetic material device according to any one of claims 1-2.

4. A method for preparing a two-dimensional magnetic material device as claimed in claim 3, characterized in that: include: A source electrode, a drain electrode and a gate are prepared on a substrate according to a preset electrode pattern; The two-dimensional magnetic material is attached to the tape and peeled off by repeatedly attaching and tearing the tape; The peeled two-dimensional magnetic material is transferred to the substrate on which the source electrode, drain electrode and gate electrode are prepared, so that the two-dimensional magnetic material is in contact with the source electrode and drain electrode to obtain a two-dimensional magnetic material device.

5. The method for preparing a two-dimensional magnetic material device according to claim 4, characterized in that: The method of preparing a source electrode, a drain electrode and a gate on a substrate according to a preset electrode pattern comprises: Coating a photoresist on a substrate, then sequentially exposing, developing, fixing and drying the substrate coated with the photoresist according to a preset electrode pattern, so as to transfer the preset electrode pattern to the substrate; A titanium layer is evaporated on the substrate after the electrode pattern is transferred by electron beam evaporation technology, and then a gold layer is evaporated by thermal evaporation technology; The excess titanium layer and gold layer on the evaporated substrate are stripped off to obtain a substrate on which a source electrode, a drain electrode and a gate electrode are prepared.

6. The method for preparing a two-dimensional magnetic material device according to claim 5, characterized in that: The method of coating the photoresist on the substrate specifically comprises: adsorbing the substrate on a coating machine and spin-coating the photoresist for multiple times, and drying the substrate at a temperature of 120° C. after each spin coating; And / or, the photoresist is selected from one or more of polymethyl methacrylate and methyl methacrylate; And / or, the exposure, development, fixing and drying are performed in sequence, wherein the development time is 30-40s, and the fixing time is 10-15s.

7. The method for preparing a two-dimensional magnetic material device according to claim 5, characterized in that: The thickness of the titanium layer is 4-6 nm, and the thickness of the gold layer is 18-22 nm; And / or, the speed of evaporating a titanium layer is 0.1-0.2Å / s, and the speed of evaporating a gold layer is 0.25-0.3Å / s.

8. The method for preparing a two-dimensional magnetic material device according to claim 4, characterized in that: Before preparing the source electrode, the drain electrode and the gate electrode on the substrate according to the preset electrode pattern, the substrate needs to be pretreated, specifically including: ultrasonically cleaning the substrate in acetone, ethanol and deionized water in turn, and drying with nitrogen after cleaning; And / or, transferring the peeled two-dimensional magnetic material to a substrate on which a source electrode, a drain electrode and a gate have been prepared, including: transferring the peeled two-dimensional magnetic material to polydimethylsiloxane to obtain a composite film, transferring the composite film to a substrate on which a source electrode, a drain electrode and a gate have been prepared, and making the two-dimensional magnetic material contact with the source electrode and the drain electrode, and then removing the polydimethylsiloxane; And / or, the operations of transferring the peeled two-dimensional magnetic material to the substrate on which the electrodes are prepared, so that the two-dimensional magnetic material is in contact with the source electrode and the drain electrode, and obtaining the two-dimensional magnetic material device are all carried out in a glove box, and the water content of the glove box is less than 0.1ppm, and the oxygen content is less than 0.1ppm.

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