Applications of fe5ge te2 material, magnetoresistive angle sensor and applications thereof

Abstract

The application provides an application of Fe5GeTe2 material, a magnetoresistance angle sensor and an application of the magnetoresistance angle sensor. The application provides an application of Fe5GeTe2 material in a magnetoresistance angle sensor, wherein the material of a magnetoresistance sheet in the magnetoresistance angle sensor is Fe5GeTe2 layered material, and the average thickness of the Fe5GeTe2 layered material is 17nm-188nm. Under certain temperature and magnetic field intensity, with the change of the angle between the plane of the Fe5GeTe2 material and the direction of the magnetic field, the longitudinal resistance and the Hall resistance of the Fe5GeTe2 material will obviously change, and based on this, the Fe5GeTe2 material can be applied to the magnetoresistance angle sensor, and the angle detection range can reach 360 degrees at most. The magnetoresistance angle sensor adopting the magnetoresistance sheet has the characteristics of sensitive reaction, high resolution, wide detection range, wide application surface and small structure, and the application range of the Fe5GeTe2 material is expanded.

Description

TECHNICAL FIELD

[0001] The application relates to the field of two-dimensional magnetic materials, in particular to an application of Fe5GeTe2 material, a magnetic resistance angle sensor and application thereof. BACKGROUND

[0002] Fe5GeTe2 is a two-dimensional (2D) van der Waals (vdW) material, which has a Curie temperature of up to 310K, and the magnetization and anomalous Hall effect thereof both present non-monotonic variation with the decrease of temperature, therefore, the current researches mainly focus on the magnetic properties, and at present, one of the applications of the Fe5GeTe2 material is to prepare a nonlinear Hall device by using the nonlinear Hall effect, which limits the application range to a certain extent. SUMMARY

[0003] The main purpose of the application is to provide an application of Fe5GeTe2 material, a magnetic resistance angle sensor and application thereof, so as to solve the technical problem that the application of Fe5GeTe2 is limited.

[0004] In order to achieve the above purpose, the application provides an application of Fe5GeTe2 material in a magnetic resistance angle sensor, wherein the magnetic resistance sheet in the sensing unit is made of Fe5GeTe2 layered material, and the average thickness of the Fe5GeTe2 layered material is 17nm-188nm.

[0005] According to the embodiment of the application, the average thickness of the Fe5GeTe2 layered material is 17nm-44nm.

[0006] The application also provides a magnetic resistance angle sensor, which comprises at least one sensing unit, the magnetic resistance sheet in the sensing unit is made of Fe5GeTe2 layered material, and the average thickness of the Fe5GeTe2 layered material is 17nm-188nm.

[0007] According to the embodiment of the application, the number of the sensing units is one, the sensing unit comprises a working circuit and a signal processing circuit which are both electrically connected with the magnetic resistance sheet, and the signal processing circuit is used for measuring the longitudinal resistance of the magnetic resistance sheet; the longitudinal resistance is the resistance of the working circuit between two access points on the magnetic resistance sheet.

[0008] According to the embodiment of the application, the number of the sensing units is two.

[0009] Any of the sensing units comprises a working circuit and a signal processing circuit, both of which are electrically connected to the magnetoresistance sheet, and the signal processing circuit is used to measure the longitudinal resistance of the magnetoresistance sheet; and the signal processing circuit in at least one of the sensing units is used to measure the Hall resistance of the magnetoresistance sheet.

[0010] The longitudinal resistance is the resistance of the working circuit between two access points on the magnetoresistance sheet.

[0011] The measurement direction of the Hall resistance is perpendicular to the current direction of the working circuit to form a current in the magnetoresistance sheet.

[0012] The measurement directions of the Hall resistances of the two sensing units are parallel, and the included angle between the working surfaces of the two sensing units is 45°.

[0013] The application also provides an application of the above-mentioned magnetoresistance angle sensor in angle calibration, comprising the following steps:

[0014] The magnetoresistance angle sensor is arranged on a reference surface of a mechanism to be calibrated, wherein the working surface of the magnetoresistance sheet in any of the sensing units of the magnetoresistance angle sensor maintains a first preset angle with the reference surface.

[0015] Under the conditions that the direction of the magnetic field in the calibration area maintains a second preset angle with a target plane of the reference surface and the temperature is 160K-25℃, the angle between the reference surface and the target plane is adjusted until the output resistance of any of the sensing units reaches a target value; wherein the target plane is the plane in which the reference surface is located in the calibration state, the magnetic field is ≥5T; and the output resistance includes the longitudinal resistance and the Hall resistance output by the magnetoresistance sheet.

[0016] According to the embodiments of the application, under the conditions that the temperature in the calibration area is 160K-25℃ and the magnetic field range is a magnetic field ≥5T, the average thickness of the Fe5GeTe2 layered material is 17nm.

[0017] According to the embodiments of the application, under the conditions that the temperature in the calibration area is 160K-250K and the magnetic field range is a magnetic field ≥5T, the average thickness of the Fe5GeTe2 layered material is 44nm.

[0018] According to the embodiments of the application, under the conditions that the temperature in the calibration area is 160K-170K and the magnetic field range is a magnetic field ≥5T, the average thickness of the Fe5GeTe2 layered material is 188nm.

[0019] According to the embodiments of the application, the first preset angle is 90° or 0°; and the second preset angle is 90° or 0°.

[0020] In the Fe5GeTe2 material described above, the applicant has found that when the Fe5GeTe2 material has an average thickness of 17nm-188nm, the longitudinal resistance and the Hall resistance of the Fe5GeTe2 material will change obviously with the change of the angle between the plane of the Fe5GeTe2 material and the direction of the magnetic field under certain temperature and magnetic field intensity. Based on this, the Fe5GeTe2 material can be applied to a magnetoresistance angle sensor, and the angle detection range can be up to 360 degrees. The magnetoresistance angle sensor using the magnetoresistance sheet has the characteristics of sensitive response, high resolution, wide detection range, wide application surface, and small structure, thereby expanding the application range of the Fe5GeTe2 material. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the drawings shown.

[0022] Figure 1 FIG. 1 is a structural schematic diagram of a sensing unit stack in a magnetoresistance angle sensor according to an embodiment of the present application;

[0023] Figure 2 FIG. 2 is a circuit connection structural schematic diagram of a sensing unit in a magnetoresistance angle sensor according to an embodiment of the present application;

[0024] Figure 3 FIG. 3 is a side view structural schematic diagram of a sensing unit according to an embodiment of the present application;

[0025] Figure 4 FIG. 4 is an optical diagram of a sensing unit in a magnetoresistance angle sensor according to an embodiment of the present application;

[0026] Figure 5 FIG. 5 is an ADMR diagram of a magnetoresistance angle sensor with a Fe5GeTe2 film thickness of 17nm at high temperature according to an embodiment of the present application;

[0027] Figure 6 FIG. 6 is a schematic diagram of an ADMR before and after a 45° translation at a temperature of 300K of a magnetoresistance angle sensor with a Fe5GeTe2 film thickness of 17nm according to an embodiment of the present application;

[0028] Figure 7 FIG. 7 is a graph of the relationship between the Hall resistance and the angle at a temperature of 300K of a magnetoresistance angle sensor with a Fe5GeTe2 film thickness of 17nm according to an embodiment of the present application;

[0029] Figure 8ADMR figure of the Fe5GeTe2 film thickness of 17nm magnetic resistance angle sensor of one embodiment of the present application under different magnetic fields;

[0030] Figure 9 ADMR figure of the Fe5GeTe2 film thickness of 17nm magnetic resistance angle sensor of one embodiment of the present application under low temperature;

[0031] Figure 10 ADMR figure of the Fe5GeTe2 film thickness of 44nm magnetic resistance angle sensor of one embodiment of the present application under high temperature;

[0032] Figure 11 ADMR figure of the Fe5GeTe2 film thickness of 188nm magnetic resistance angle sensor of one embodiment of the present application under different temperatures;

[0033] Figure 12 AFM step figure of the Fe5GeTe2 film of embodiment 1 of the present application;

[0034] Figure 13 AFM step figure of the Fe5GeTe2 film of embodiment 2 of the present application;

[0035] Figure 14 AFM step figure of the Fe5GeTe2 film of embodiment 3 of the present application.

[0036] The purposes, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings.

[0037] 10, substrate; 20, magnetic resistance sheet; 30, packaging layer; 40, working circuit; 50, signal processing circuit. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0039] It should be noted that all the directionality indications (such as up, down, …) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directionality indications also change accordingly.

[0040] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implying the number of the indicated technical features. Therefore, the features defined as "first" and "second" can be explicitly or implicitly included at least one of the features.

[0041] Furthermore, the technical solutions among the various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0042] The present application provides an application of Fe5GeTe2 material in a magnetoresistance angle sensor. The magnetoresistance angle sensor comprises a sensing unit, and the material of a magnetoresistance sheet in the sensing unit is Fe5GeTe2 layered material. The average thickness of the Fe5GeTe2 layered material is 17 nm to 188 nm.

[0043] The magnetoresistance sheet has a magnetoresistance effect (MR), that is, a MR element, and an angle-dependent magnetoresistance effect (ADMR), which is the core part of the sensor. The longitudinal resistance value of the Fe5GeTe2 material changes with the change of the magnetic field direction. Therefore, the material of the magnetoresistance sheet is selected as the Fe5GeTe2 material. The average thickness of the magnetoresistance sheet is thin, which is a sheet structure, and the average thickness is 17 nm to 188 nm. Therefore, in the embodiments of the present application, the magnetoresistance sheet can also be referred to as Fe5GeTe2 layered material or Fe5GeTe2 nanosheet.

[0044] The magnetoresistance sheet has two oppositely arranged surfaces perpendicular to the average thickness direction of itself. The two surfaces are relatively flat, of course, due to the preparation method (for example, the Fe5GeTe2 sheet is obtained by mechanically peeling the bulk single crystal Fe5GeTe2 from the transparent tape), which determines that the surface is not completely flat. One of the surfaces will be connected to some electrodes used to form the necessary circuit.

[0045] In some embodiments, referring to Figure 1 , the sensing unit in the magnetoresistance angle sensor further comprises a substrate 10 and a packaging layer 30. As Figure 1 shown, the lowest is the substrate 10, the middle is the magnetoresistance sheet 20, that is, the Fe5GeTe2 film, through which the current flows, and the uppermost is the packaging layer 30, which is an insulating material, such as h-BN film, used to package the Fe5GeTe2 film to prevent it from being oxidized.

[0046] The substrate 10 is provided with electrodes, and the magnetoresistive sheet 20 is arranged on the substrate 10, and one surface of the magnetoresistive sheet 20 is connected with the electrodes of the substrate 10. The surface can be referred to as a working surface of the magnetoresistive sheet 20. For the convenience of description, the two opposite surfaces can be referred to as a bottom surface and a top surface. Generally, the bottom surface is connected with the electrodes and serves as the working surface.

[0047] Referring to Figure 2 , a schematic diagram of a main structure of a sensing unit in the magnetoresistive angle sensor. The Cr / Au electrodes are deposited on the substrate 10 by a photolithography evaporation method, and then the Fe5GeTe2 film and the h-BN film are covered on the electrodes to ensure that the four ends of the electrodes are located below the four ends of the films.

[0048] It can be understood that, as Figure 2 indicated, the substrate 10 (including the electrodes on the substrate 10), the Fe5GeTe2 film, and the encapsulation layer 30 constitute the sensing unit of the magnetoresistive angle sensor. The current is input through the two electrodes in the x direction to flow through the Fe5GeTe2 film, and the longitudinal voltage is measured through the two electrodes in the x direction, and the Hall voltage is measured through the two electrodes in the y direction, and then the longitudinal resistance value and the Hall resistance value are obtained.

[0049] When the number of sensing units is one, the magnetoresistive angle sensor is a one-type magnetoresistive angle sensor. The signal processing circuit of the one-type magnetoresistive angle sensor only measures the longitudinal resistance value.

[0050] When the number of sensing units is two, the magnetoresistive angle sensor is a two-type magnetoresistive angle sensor. The structure can be referred to Figure 3 , Figure 3 , a schematic diagram of a structure of the two-type magnetoresistive angle sensor. The two sensing units are arranged in an overlapping manner, the intersection line is parallel to the y axis, and the included angle between the two sensing units is 45°. In the signal processing circuit of the two-type magnetoresistive angle sensor, for one sensing unit, the signal processing circuit measures both the longitudinal resistance value and the Hall resistance value. For another sensing unit, the signal processing circuit can only measure the longitudinal resistance value, or can measure both the longitudinal resistance value and the Hall resistance value.

[0051] The one-type magnetoresistive angle sensor formed by one sensing unit can detect a range of 0-90 degrees, and the bottom surface of the sensing unit is referred to as the bottom surface of the one-type magnetoresistive angle sensor. The two-type magnetoresistive angle sensor formed by two same sensing units has an angle detection range of 0-360 degrees, and the bottom surface of one of the sensing units is artificially set as the bottom surface of the two-type magnetoresistive angle sensor. When the angle detection range is not emphasized, the one-type and the two-type magnetoresistive angle sensors are collectively referred to as the magnetoresistive angle sensor.

[0052] When a certain sensing unit needs to measure the longitudinal resistance value and the Hall resistance value, the structure can be referred toFigure 4 , Figure 4 is the optical image of the sensing unit in the magnetoresistance angle sensor. The substrate 10 is SiO2 / Si, the rectangular around is the metal electrode, and the Fe5GeTe2 thin film is covered in the center of the electrode. The uppermost is covered by the h-BN thin film, which avoids the Fe5GeTe2 thin film from contacting the air and prevents its oxidation. Figure 4 A pair of metal electrodes along the x direction in the above sensing unit is used to detect the longitudinal resistance value, and a pair of metal electrodes along the y direction can be used to measure the Hall resistance value. Of course, the sensing unit is also applicable to measuring only the longitudinal resistance value.

[0053] From the above preparation method, it can be known that the average thickness of the magnetoresistance sheet 20 can also be understood as the average thickness. For example, the Fe5GeTe2 nanosheet with a thickness of 17 nm can be understood as that the average thickness value is relatively uniform, and the average thickness is 17 nm.

[0054] The average thickness of the magnetoresistance sheet 20 is 17 nm to 188 nm, and the magnetoresistance sheet 20 includes products of various specifications, such as the magnetoresistance sheet 20 with an average thickness of 17 nm, 20 nm, 30 nm, 40 nm, 44 nm, 56 nm, 71 nm, 87 nm, 90 nm, 100 nm, 155 nm, and 188 nm.

[0055] The applicant found that when the Fe5GeTe2 material has an average thickness of 17 nm to 188 nm, under certain temperature and magnetic field strength conditions, when the angle between the plane where the Fe5GeTe2 material is located and the magnetic field direction changes, such as when the working surface is parallel to the magnetic field and becomes perpendicular to the magnetic field, the longitudinal resistance of the Fe5GeTe2 material will change obviously. Therefore, it can be used as a magnetoresistance sheet 20.

[0056] Exemplarily, under the following conditions:

[0057] Temperature range: 160 K to room temperature; magnetic field range: 5 T or more; thickness range: 17 nm. The one-type magnetoresistance angle sensor can detect a range of 90 degrees, and the two-type magnetoresistance angle sensor can detect a full range of 360 degrees.

[0058] Exemplarily, under the following conditions:

[0059] Temperature range: 160 K to 250 K; magnetic field range: 5 T or more; thickness range: 44 nm. The one-type magnetoresistance angle sensor can detect a range of 90 degrees, and the two-type magnetoresistance angle sensor can detect a full range of 360 degrees.

[0060] Exemplarily, under the following conditions:

[0061] Temperature range: 160K to 170K; magnetic field range: 5T or more; thickness range: 188nm. The angle sensor of the first type can detect a range of 90 degrees, and the angle sensor of the second type can detect a full range of 360 degrees.

[0062] Exemplarily, in the following conditions:

[0063] Temperature range: extremely low temperature T = 10K to 30K; magnetic field range: 5T or more; average thickness: 17nm. In some embodiments, the average thickness of the Fe5GeTe2 layered material is 17nm. The angle sensor of the first type can detect the two orientations of θ equal to 90 degrees and 270 degrees with extremely high sensitivity and extremely high speed.

[0064] The temperature and magnetic field strength conditions are exemplarily provided by the working environment of the angle sensor, such as the room temperature of the use environment, which is exactly 300K. For example, the temperature in space is low, which can reach 10K to 30K, i.e., the angle sensor is used in space equipment. For another example, liquid helium is used to provide a test environment of 10K to 30K, and the angle sensor is used to measure an object such as a mechanism to be calibrated, and after calibration is completed, the angle sensor is separated from the test environment.

[0065] Exemplarily, the temperature and magnetic field strength conditions are provided by the structure of the angle sensor itself or the object to be measured. For example, the object to be measured has the above-mentioned temperature and magnetic field range.

[0066] In the above-mentioned Fe5GeTe2 material, the applicant has found that when the Fe5GeTe2 material has an average thickness of 17nm to 188nm, the longitudinal resistance and Hall resistance of the Fe5GeTe2 material will change obviously with the change of the angle between the plane of the Fe5GeTe2 material and the direction of the magnetic field under certain temperature and magnetic field strength conditions. Therefore, the Fe5GeTe2 material can be applied to the angle sensor and used as the magnetic resistance sheet 20 in the angle sensor. The angle sensor using the above-mentioned magnetic resistance sheet 20 has the characteristics of wide detection range, sensitive reaction, high resolution, wide application surface, and small structure, which expands the application range of the Fe5GeTe2 material.

[0067] Correspondingly, the application also provides an angle sensor, which comprises at least one sensing unit, and the material of the magnetic resistance sheet 20 in the sensing unit is Fe5GeTe2 layered material, and the average thickness of the Fe5GeTe2 layered material is 17nm to 188nm.

[0068] The above-described magnetic resistance angle sensor has the characteristics of wide applicable temperature range, large detection range, high stability, extremely small structure, extremely sensitive response at low temperature, and extremely high resolution, because the Fe5GeTe2 material is used as the magnetic resistance sheet 20.

[0069] In some embodiments, the number of sensing units is one, and each sensing unit includes the working circuit 40 and the signal processing circuit 50, which are electrically connected to the magnetic resistance sheet 20, and the signal processing circuit 50 is used to measure the longitudinal resistance of the magnetic resistance sheet 20. The longitudinal resistance is the resistance of the working circuit 40 between two access points on the magnetic resistance sheet 20. In this case, the magnetic resistance angle sensor is a type I magnetic resistance angle sensor.

[0070] In some specific embodiments, the input voltage in the working circuit 40 is 20 mV to 70 mV, and the input current in the working circuit 40 is 0.2 mA to 0.5 mA.

[0071] In other embodiments, the number of sensing units is two, the measurement directions of the Hall resistances of the two sensing units are parallel, and the included angle between the working surfaces of the two sensing units is 45°. That is, as shown in FIG. 2B. Figure 3 Figure 3 FIG. 2B is a structural schematic diagram of a type II magnetic resistance angle sensor, and the two sensing units are arranged in an overlapping manner, the intersection line is parallel to the y-axis, and the included angle between the two sensing units is 45°.

[0072] Each sensing unit includes the working circuit 40 and the signal processing circuit 50, which are electrically connected to the magnetic resistance sheet 20, and the signal processing circuit 50 is used to measure the longitudinal resistance of the magnetic resistance sheet 20. In addition, the signal processing circuit 50 in at least one sensing unit is used to measure the Hall resistance of the magnetic resistance sheet 20. The longitudinal resistance is the resistance of the working circuit 40 between two access points on the magnetic resistance sheet 20. The measurement direction of the Hall resistance is perpendicular to the current direction in which the working circuit 40 forms the current in the magnetic resistance sheet 20.

[0073] For example, the magnetic resistance sheet 20 is provided with two groups of electrodes, the first group of electrodes is arranged opposite to each other along the first direction of the magnetic resistance sheet 20, such as the x direction, and the second group of electrodes is arranged opposite to each other perpendicular to the first direction of the magnetic resistance sheet 20. In this way, the working circuit 40 is connected to two electrodes of the first group of electrodes, and if the signal processing circuit 50 is connected to two electrodes of the second group of electrodes, the Hall resistance is measured, and if the signal processing circuit 50 is connected to two electrodes of the first group of electrodes, the longitudinal resistance is measured. The signal processing circuit 50 can include an amplifier, a filter, an analog-to-digital converter, etc.

[0074] ​It can be understood that the working circuit 40 and the signal processing circuit 50 are not necessary structures of the magnetoresistive angle sensor, i.e., as in some embodiments, the working circuit 40 and the signal processing circuit 50 of the measured object, such as the mechanism to be calibrated, are present, as long as the working circuit 40 and the signal processing circuit 50 of the mechanism to be calibrated are connected with the magnetoresistive angle sensor.

[0075] In some embodiments, the average thickness of the Fe5GeTe2 layered material is 17 nm to 44 nm.

[0076] The application also provides an application of the above-mentioned magnetoresistive angle sensor in angle calibration, comprising the following steps:

[0077] The magnetoresistive angle sensor is arranged on a reference surface of the mechanism to be calibrated, wherein the working surface of the magnetoresistive chip 20 in any sensing unit of the magnetoresistive angle sensor maintains a first preset angle with the reference surface.

[0078] Under the condition that the direction of the magnetic field in the calibration area maintains a second preset angle with the target plane of the reference surface and the temperature is 160 K to 25°C, the angle between the reference surface and the target plane is adjusted until the output resistance in any sensing unit reaches a target value; wherein the target plane is the plane in which the reference surface is located in the calibration state, and the magnetic field is ≥5 T; the output resistance includes the longitudinal resistance and the Hall resistance corresponding to the output of the magnetoresistive chip.

[0079] The above-mentioned magnetoresistive angle sensor can be used for angle calibration of the mechanism, such as the angle during installation. In some precision grinding instruments, the mechanism to be calibrated usually needs to ensure that its angle with other parts is at a suitable angle, at which time the mechanism is in a calibration state. In this state, the plane in which the reference surface of the mechanism to be calibrated is located is the target plane.

[0080] The working surface of the magnetoresistive chip 20 is fixed on the reference surface of the mechanism to be calibrated and maintains a first preset angle, such as 0°, 13°, 35°, 68° or 90°, with the reference surface. The direction of the magnetic field maintains a second preset angle with the target plane of the reference surface. Therefore, in the calibration state, the included angle between the direction of the magnetic field and the working surface is a fixed value, such as 0°, 21°, 47°, 76° or 90°. The corresponding longitudinal resistance is a target value. If the longitudinal resistance deviates from the target value, it indicates that there is an included angle between the reference surface of the mechanism to be calibrated and the target plane. The angle between the reference surface and the target plane is adjusted until the longitudinal resistance of the magnetoresistive angle sensor reaches the target value, i.e., the calibration is completed.

[0081] In some embodiments, under the condition that the temperature in the calibration area is 160 K to 25°C and the magnetic field range is a magnetic field ≥5 T, the average thickness of the Fe5GeTe2 layered material is 17 nm.

[0082] In some embodiments, under the conditions that the temperature in the calibration area is 160K to 250K and the magnetic field range is ≥5T, the average thickness of the Fe5GeTe2 layered material is 44nm.

[0083] In some embodiments, under the conditions that the temperature in the calibration area is 160K to 170K and the magnetic field range is ≥5T, the average thickness of the Fe5GeTe2 layered material is 188nm.

[0084] In some embodiments, the first preset angle may be the same as or different from the second preset angle.

[0085] In some embodiments, the first preset angle is 90° or 0°; under this condition, the working surface of the magnetoresistive angle sensor's bottom magnetoresistive sheet 20 is perpendicular or parallel to the reference plane. This facilitates the mounting of the magnetoresistive angle sensor on the mechanism to be calibrated.

[0086] The second preset angle is 90° or 0°. Under this condition, the working surface of the magnetoresistive angle sensor's bottom magnetoresistive sheet 20 is perpendicular or parallel to the magnetic field direction. When an angular deviation occurs, the longitudinal resistance value will shift to a stable position.

[0087] Example 1

[0088] Cr / Au (5nm / 50nm) electrodes are deposited on a thermally oxidized silicon substrate 10. The electrodes include a first set of electrodes along the x-direction and a second set of electrodes along the y-direction.

[0089] Fe5GeTe2 thin films, 17 nm thick, were obtained by mechanically peeling off bulk single-crystal Fe5GeTe2 using transparent tape. An AFM step pattern of one of the Fe5GeTe2 thin films is shown below. Figure 12 As shown.

[0090] The thin film was then transferred onto the first and second sets of electrodes using polydimethylsiloxane. To prevent degradation, these devices were encapsulated with hexagonal boron nitride (h-BN) films to obtain Fe5GeTe2 devices, which constitute a sensing unit in a magnetoresistive angle sensor. All fabrication processes were carried out in an inert gas glove box, with oxygen and water content maintained well below 0.01 ppm.

[0091] The magnetic transport measurements of Fe5GeTe2 devices were performed in a Quantum Design designed Physical Properties Measurement System (PPMS) in the temperature range of 10 K to 300 K and magnetic field range of 0-9 T. The current (I) was provided by a Keithley 2400 source meter. The voltage of 70 mV and the current of 0.2 mA can be regarded as the working circuit 40.

[0092] The longitudinal (x-direction) and Hall resistance (y-direction) were measured simultaneously by two Keithley 2182A nanovoltmeters, which can be regarded as the signal processing circuit 50.

[0093] The magnetic field B is deflected in the zx plane (z-direction is the thickness direction of the magnetoresistance sheet 20, and is perpendicular to the y-direction and the x-direction). The angle between the magnetic field direction and the z-direction is θ, when θ is 0°, B is parallel to the z-direction; when θ is 90°, B is parallel to the x-direction. The relationship between the longitudinal resistance and the Hall resistance and the magnetic field angle under different magnetic field sizes of the magnetic field B was measured, and the measurement results are shown in Figures 5 to 9

[0094] Example 2

[0095] Cr / Au (5 nm / 50 nm) electrodes were deposited on the thermal oxide silicon substrate 10. The electrodes include a first group of electrodes along the x-direction and a second group of electrodes along the y-direction.

[0096] Fe5GeTe2 flakes were mechanically exfoliated from a bulk single-crystal Fe5GeTe2 by transparent tape, and the thickness of the Fe5GeTe2 flakes was 44 nm. An AFM image of a certain Fe5GeTe2 flake is shown in Figure 13

[0097] Then the flakes were transferred to the first group of electrodes and the second group of electrodes by polydimethylsiloxane. In order to avoid degradation, these devices were packaged with a hexagonal boron nitride (h-BN) film to obtain Fe5GeTe2 devices, which constitute a sensing unit in the magnetoresistance angle sensor. All preparation processes were carried out in an inert gas glove box, and the oxygen and water content was kept far below 0.01 ppm.

[0098] ​​Magnetic transport measurements of Fe5GeTe2 devices were performed in a Quantum Design designed Physical Properties Measurement System (PPMS) in the temperature range of 10 K to 300 K and magnetic field range of 0-9 T. The current (I) was provided by a Keithley 2400 source meter. The voltage of 40 mV and the current of 0.5 mA can be regarded as the working circuit 40.

[0099] The longitudinal (x-direction) and Hall resistance (y-direction) were measured simultaneously by two Keithley 2182A nanovoltmeters, which can be regarded as the signal processing circuit 50.

[0100] The magnetic field direction of the magnetic field B is deflected in the zx plane (the z-direction is the thickness direction of the magnetoresistance sheet 20, and is perpendicular to the y-direction and the x-direction). The angle between the magnetic field direction and the z-direction is θ, when θ is 0°, B is parallel to the z-direction; when θ is 90°, B is parallel to the x-direction. The relationship between the longitudinal resistance and the magnetic field angle under different magnetic field sizes of the magnetic field B was measured, and the measurement results are shown in Figure 10

[0101] Example 3

[0102] Cr / Au (5 nm / 50 nm) electrodes were deposited on a thermally oxidized silicon substrate 10. The electrodes include a first group of electrodes along the x-direction and a second group of electrodes along the y-direction.

[0103] Fe5GeTe2 flakes were mechanically exfoliated from a bulk single-crystal Fe5GeTe2 by transparent tape, wherein the thickness of the Fe5GeTe2 flakes was 188 nm. An AFM step graph of a certain Fe5GeTe2 flake is shown in Figure 14

[0104] Then the flakes were transferred to the first group of electrodes and the second group of electrodes by polydimethylsiloxane. In order to avoid degradation, these devices were packaged with a hexagonal boron nitride (h-BN) film to obtain Fe5GeTe2 devices, which constitute a magnetoresistance angle sensor. All preparation processes were carried out in an inert gas glove box, and the oxygen and water content was kept far below 0.01 ppm.

[0105] ​​Magnetic transport measurements of the Fe5GeTe2 device were performed using a Physical Properties Measurement System (PPMS) designed by Quantum Design, covering a temperature range of 10K to 300K and a magnetic field range of 0–9T. Current (I) was provided by a Keithley 2400 source meter. The voltage was 30mV and the current was 0.5mA, which can be considered as a working circuit 40.

[0106] The longitudinal (x-direction) and Hall resistance (y-direction) are measured simultaneously by two sets of Keithley 2182A nanovoltmeters, which can be regarded as signal processing circuit 50.

[0107] The magnetic field direction of magnetic field B deflects within the zx plane (the z-direction is the thickness direction of the magnetoresistive sheet 20, and is perpendicular to both the y and x directions). The angle between the magnetic field direction and the z-direction is θ. When θ is 0°, B is parallel to the z-direction; when θ is 90°, B is parallel to the x-direction. The relationship between the longitudinal resistance and the magnetic field angle is measured under different magnetic field strengths. The measurement results are as follows: Figure 11 As shown.

[0108] analyze

[0109] Comparing the results of Examples 1-3, it can be seen that when the magnetic field B is based on Figure 2 As shown, when rotating in the xz plane, the longitudinal resistance has a quantifiable and specific relationship with the angle. For the sake of quantification and simplicity, ADMR is used to describe the change of longitudinal resistance with angle. ADMR is defined as [R(θ)-R(0)] / R(0)×100%. The angle θ is defined as the angle between the magnetic field and the normal direction of the thin film, that is, the angle between the magnetic field direction and the +z direction.

[0110] Figure 5The ADMR of 17nm Fe5GeTe2 film at 160K, 210K, 250K and 300K with a fixed magnetic field of 7T is shown. θ=0° means the magnetic field is perpendicular to the film (i.e. the magnetic field is along +z direction), θ=90° means the magnetic field is parallel to the film (i.e. the magnetic field is along +x direction), θ=180° means the magnetic field is along -z direction, and θ=270° means the magnetic field is along -x direction. Obviously, in this temperature range, the ADMR shows a double angle relationship with the angle, and the ADMR has a minimum value when θ=0°, which means the magnetic field is perpendicular to the film, and the ADMR has a maximum value when θ=90°, which means the magnetic field is parallel to the x direction. When θ is between 0° and 90°, the ADMR can also have a fixed value due to the double angle relationship. Due to the periodicity, the single Fe5GeTe2 film can be applied to an angle sensor between 0° and 90°. As the temperature gradually increases from 160K to 300K, the amplitude of the ADMR gradually decreases, but the change trend remains unchanged, and the shape of the curve becomes more similar to the double angle relationship of the cosine function as the temperature increases. Therefore, when the temperature is between 160K and 300K and the magnetic field is greater than 5T, the 17nm Fe5GeTe2 film can be applied to an angle sensor, and the better the temperature is close to room temperature, the better the angle sensor effect is.

[0111] Figure 6 The ADMR of 17nm Fe5GeTe2 film at 300K with a fixed magnetic field of 7T is shown, and the horizontal axis is shifted by 45°. Figure 4 The results show that due to the periodicity of the ADMR, the single Fe5GeTe2 film can only be applied to an angle sensor between 0° and 90°, and any one ADMR value corresponds to four θ values. (For example, the ADMR values of 45°, 135°, 225° and 315° are all one value) In order to make each ADMR correspond to fewer θ values, two identical Fe5GeTe2 films are overlapped and arranged, the intersection line is parallel to the y axis, and the film surface forms a 45° angle. In this way, the ADMR is shifted by 45°. Obviously, by Figure 5 the difference between the two curves in the above and the change of the angle can make any one ADMR value correspond to only two θ values. (45° and 225° correspond, and 135° and 315° correspond)

[0112] Figure 7 The Hall resistance R xyThe relationship with the angle θ. Obviously, the Hall resistance and the angle present a double-angle relationship of the cosine function, and the data of 0-180 degrees and 180-360 degrees are one-to-one correspondence, so for a certain ADMR value, the Hall resistance can distinguish whether the corresponding angle is located in 0-180 degrees or 180-360 degrees. At this point, through the angle sensor composed of two identical Fe5GeTe2 films, any angle of 0-360 degrees can be detected.

[0113] Figure 8 The ADMR of the 17nm Fe5GeTe2 film at a temperature of 10K and a magnetic field of 5T, 7T and 9T respectively is shown. Obviously, within this magnetic field range, the ADMR and the angle θ have a double-angle and quadruple-angle superposition relationship of the cosine function. Due to the quadruple-angle factor, it is clear that when the angle is 90 degrees, the ADMR has a maximum value, and the peak formed by this maximum value is very steep. When the angle changes slightly near 90 degrees, the value of the ADMR will change significantly, so it can be used as an angle sensor to accurately and quickly detect that θ is equal to 90 degrees and 270 degrees, and has extremely high sensitivity when calibrating other structures.

[0114] Figure 9 The ADMR of the 17nm Fe5GeTe2 film at a temperature of 10K, 20K and 30K and a magnetic field of 7T is shown. It is clear that the quadruple-angle behavior causes the 90-degree peak to be very obvious at low temperatures, and is gradually suppressed as the temperature rises. The peak height at T=30K is only half of the peak height at T=10K, but the peak is still steep, and still has extremely high sensitivity when calibrating other structures as an angle sensor. Therefore, when the temperature range is 10K-30K and the magnetic field range is 5T-9T, the Fe5GeTe2 film can be used as a calibrator because of the relationship between its ADMR and the angle θ, and has extremely high sensitivity.

[0115] Figure 10 The ADMR of the 17nm Fe5GeTe2 film at a temperature of 10K, 20K and 30K and a magnetic field of 7T is shown. It is clear that the quadruple-angle behavior causes the 90-degree peak to be very obvious at low temperatures, and is gradually suppressed as the temperature rises. The peak height at T=30K is only half of the peak height at T=10K, but the peak is still steep, and still has extremely high sensitivity when calibrating other structures as an angle sensor. Therefore, when the temperature range is 10K-30K and the magnetic field range is 5T-9T, the Fe5GeTe2 film can be used as a calibrator because of the relationship between its ADMR and the angle θ, and has extremely high sensitivity.

[0116] Figure 11 The figure shows the ADMR of Fe5GeTe2 film with thickness of 188 nm at temperature of 160 K and 170 K, and magnetic field of 7 T. Similar to the Fe5GeTe2 films with thickness of 17 nm and 44 nm, the ADMR of Fe5GeTe2 film with thickness of 188 nm also shows that the temperature range of the double angle of the angle θ keeps changing with the increase of the thickness, and the temperature range of the Fe5GeTe2 film with thickness of 188 nm is 160 K to 170 K. Therefore, the angle sensor made of Fe5GeTe2 film with thickness of 188 nm needs to be used in the temperature range. In summary, the temperature range of the angle sensor is related to the thickness, and only when the thickness is small enough, the temperature range of the angle sensor can include room temperature. With the increase of the thickness of Fe5GeTe2 film, the temperature range of the angle sensor becomes lower and lower.

[0117] In summary, for the Fe5GeTe2 films with thickness of 17 nm to 188 nm, when the temperature range is 160 K to 300 K and the magnetic field range is 5 T to 9 T, because the ADMR of the Fe5GeTe2 film shows the relationship of the double angle of the cosine function of the angle θ, and the Hall resistance shows the relationship of the single angle of the cosine function of the angle θ, the Fe5GeTe2 film can be used to make a type of magnetoresistance angle sensor to detect the angle range of 0 to 90 degrees. Two same Fe5GeTe2 films can also be arranged to overlap, and the intersection line is parallel to the y axis, and the film surface forms an angle of 45 degrees, to make a type of magnetoresistance angle sensor. By using the relationship between the ADMR and the Hall resistance of the first Fe5GeTe2 film and the angle, and the relationship between the ADMR of the second Fe5GeTe2 film and the angle, the angle range of 0 to 360 degrees can be detected. When using the magnetoresistance angle sensor, the temperature and thickness characteristics need to be paid attention to. In the applicable temperature range of 160 K to 300 K, the closer to room temperature, the better the effect of the magnetoresistance angle sensor. The smaller the thickness, the wider the applicable temperature range of the magnetoresistance angle sensor. For example, when the thickness is small enough (17 nm), the magnetoresistance angle sensor can be used at room temperature. If the thickness is larger (44 nm), the temperature needs to be lower than room temperature (such as minus Celsius). If the thickness is particularly large (188 nm), the magnetoresistance angle sensor can only be used at a lower temperature (around 160 K). For the Fe5GeTe2 film with thickness of 17 nm, when the temperature range is 10 K to 30 K and the magnetic field range is 5 T to 9 T, because the ADMR shows the relationship of the four times angle of the angle θ, a type of magnetoresistance angle sensor can be made of a single Fe5GeTe2 film. Although it can only be used to quickly detect the two directions of θ equal to 90 degrees and 270 degrees, it has the characteristics of extremely high sensitivity.

[0118] In the above technical solution of the present application, the above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the technical concept of the present application, using the content of the present application specification and drawings, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. Use of Fe5GeTe2 material in a magnetoresistive angle sensor, characterized in that, The magnetic angle sensor comprises a sensing unit, and a material of a magnetic resistance sheet in the sensing unit is Fe5GeTe2 layered material, and an average thickness of the Fe5GeTe2 layered material is 17nm-188nm.

2. Use according to claim 1, characterized in that, The average thickness of the Fe5GeTe2 layered material is 17nm-44nm.

3. A magnetic reluctance angle sensor, characterized in that The magnetic angle sensor comprises at least one sensing unit, and a material of a magnetic resistance sheet in the sensing unit is Fe5GeTe2 layered material, and an average thickness of the Fe5GeTe2 layered material is 17nm-188nm.

4. A magnetic reluctance angle sensor according to claim 3, characterised in that, The number of the sensing units is one, and each of the sensing units comprises a working circuit and a signal processing circuit electrically connected with the magnetic resistance sheet, and the signal processing circuit is used for measuring a longitudinal resistance of the magnetic resistance sheet; and the longitudinal resistance is a resistance between two access points of the working circuit on the magnetic resistance sheet.

5. A magnetic reluctance angle sensor according to claim 3, characterised in that, The number of the sensing units is two. Each of the sensing units comprises a working circuit and a signal processing circuit electrically connected with the magnetic resistance sheet, and the signal processing circuit is used for measuring a longitudinal resistance of the magnetic resistance sheet; and the signal processing circuit in at least one of the sensing units is used for measuring a Hall resistance of the magnetic resistance sheet. The longitudinal resistance is a resistance between two access points of the working circuit on the magnetic resistance sheet. A measuring direction of the Hall resistance is perpendicular to a current direction of a current formed in the magnetic resistance sheet by the working circuit; The measuring directions of the Hall resistances corresponding to the two sensing units are parallel, and an included angle between working surfaces of the two sensing units is 45°.

6. Use of a magnetic angle sensor according to any one of claims 3 to 5 for angle calibration, characterized in that The method comprises the following steps: The magnetic angle sensor is arranged on a reference surface of a mechanism to be calibrated, and a working surface of a magnetic resistance sheet in any sensing unit of the magnetic angle sensor maintains a first preset angle with the reference surface; An angle between the reference surface and a target plane of the reference surface in a calibration area maintains a second preset angle, and a temperature is 160K-25℃, and the angle between the reference surface and the target plane is adjusted until an output resistance in any sensing unit reaches a target value, the target plane is a plane where the reference surface is located in a calibration state, a magnetic field is greater than or equal to 5T, and the output resistance comprises a longitudinal resistance and a Hall resistance output by the magnetic resistance sheet.

7. Use according to claim 6, characterized in that, In a calibration area, a temperature is 160K-25℃, a magnetic field range is greater than or equal to 5T, and an average thickness of Fe5GeTe2 layered material is 17nm.

8. Use according to claim 6, characterized in that, In a calibration area, a temperature is 160K-250K, a magnetic field range is greater than or equal to 5T, and an average thickness of Fe5GeTe2 layered material is 44nm.

9. Use according to claim 6, characterized in that, In a calibration area, a temperature is 160K-170K, a magnetic field range is greater than or equal to 5T, and an average thickness of Fe5GeTe2 layered material is 188nm.

10. Use according to any one of claim 6, characterized in that, The first preset angle is 90° or 0°, and the second preset angle is 90° or 0°.

Images