Device for Measuring Thermal Expansion and Magnetostriction of Two-Dimensional Materials

Abstract

The present invention provides a device for measuring the thermal expansion and magnetostriction of two-dimensional materials, which relates to the technical field of thermal expansion and magnetostriction measurement. The device for measuring thermal expansion and magnetostriction based on the capacitance method includes a bracket; a sample stage provided on the bracket for carrying a sample to be measured; and a capacitor plate group provided on the same side of the sample to be measured; wherein, one capacitor plate in the capacitor plate group is provided at one end of the sample to be measured, and the other capacitor plate is provided on the bracket, and the two capacitor plates form a parallel-plate capacitor. When the size of the sample changes under the action of a magnetic field or a temperature field, the position between the two capacitor plates will change relatively, thereby causing a change in the capacitance value. Based on the specific relationship between the capacitance value and the distance between the two capacitor plates, the thermal expansion and magnetostriction of the sample can be measured. The measuring device proposed in this application has a wider application range, less measuring noise, is compatible with most measuring platforms, and has high compatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal expansion and magnetostriction measurement, and particularly relates to a device for measuring thermal expansion and magnetostriction of two-dimensional materials. Background Art

[0002] The measurement of thermal expansion effect (the phenomenon of dimensional or volumetric change of an object when the temperature changes) and magnetostriction effect (the phenomenon of elongation or shortening of an object when magnetized in a magnetic field) is an important experimental method in condensed matter physics research.

[0003] Currently, the methods for measuring thermal expansion and magnetostriction mainly include using dilatometer method, strain gauge method, Bragg grating method, etc. However, the prerequisite for these methods is that the sample to be measured has sufficient rigidity. But for many key materials in condensed matter physics research, including van der Waals two-dimensional materials (a type of two-dimensional layered material stacked by van der Waals forces), most of them are relatively soft, and the above methods cannot be used to measure thermal expansion and magnetostriction.

[0004] Based on this, the present application intends to propose a device for measuring thermal expansion and magnetostriction of two-dimensional materials, which is at least used for measuring thermal expansion and magnetostriction of various materials including van der Waals two-dimensional materials. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a device for measuring thermal expansion and magnetostriction of two-dimensional materials, which at least solves the technical problems that the prior art cannot measure the thermal expansion effect and magnetostriction effect of samples with poor rigidity.

[0007] (II) Technical Solutions

[0008] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0009] A device for measuring thermal expansion and magnetostriction of two-dimensional materials, the device includes:

[0010] A bracket;

[0011] A sample stage provided on the bracket for carrying the sample to be measured; and

[0012] A capacitor plate group provided on the same side of the sample to be measured; wherein, one capacitor plate in the capacitor plate group is provided at one end of the sample to be measured, and the other capacitor plate is provided on the bracket, and the two capacitor plates form a parallel plate capacitor.

[0013] In one embodiment, the bracket is in an inverted "L" shape.

[0014] In one embodiment, the sample stage is movably connected to the bracket through a position adjustment mechanism.

[0015] Preferably, the position adjustment mechanism includes a position adjustment portion formed on the bracket and parallel to the spacing direction between the capacitor plate groups, and a positioning portion detachably connected to the position adjustment portion.

[0016] More preferably, the position adjustment portion is a through groove formed on the bracket along the direction parallel to the spacing between the capacitor plate groups, and the positioning portion is a fastening screw.

[0017] In one embodiment, the bracket, the sample stage, and the position adjustment mechanism are all made of non-magnetic metal materials.

[0018] Preferably, the non-magnetic metal materials include, but are not limited to, non-magnetic steel, aluminum and aluminum alloys, copper and copper alloys, titanium and titanium alloys, and precious metals.

[0019] In one embodiment, the capacitor plates include, but are not limited to, copper foil, aluminum foil, tantalum foil, and metallized film.

[0020] In one embodiment, the measuring device further includes: an electrode wiring groove for accommodating the electrode wire led out from the electrode of the capacitor plate;

[0021] The electrode wiring groove includes a first electrode wiring groove and a second electrode wiring groove; wherein, the second electrode wiring groove is formed on the top surface of the bracket for accommodating the electrode wire led out from the electrode of the capacitor plate at the top end of the bracket, and the first electrode wiring groove is for accommodating the electrode wire led out from the electrode of the capacitor plate on the other side of the sample to be measured.

[0022] Preferably, the first electrode wiring groove is integrally provided with the position adjustment portion of the position adjustment mechanism.

[0023] In one embodiment, the measuring device further includes: a measuring rod, the measuring device is fixed on the measuring rod, and the electrode wire is connected to the measuring wire on the measuring rod.

[0024] In one embodiment, the measuring device further includes a metal shielding cover for reducing the noise that affects the measurement result generated by external electromagnetic waves.

[0025] (III) Beneficial Effects

[0026] The present invention provides a device for measuring the thermal expansion and magnetostriction of two-dimensional materials. Compared with the prior art, it has the following beneficial effects:

[0027] The device for measuring the thermal expansion and magnetostriction of two-dimensional materials proposed in this application includes: a bracket; a sample stage provided on the bracket for carrying the sample to be measured; and a group of capacitor plates provided on the same side of the sample to be measured, and the group of capacitor plates forms a parallel-plate capacitor for feeding back the capacitance value generated due to the change in the distance between the capacitor plates. The device for measuring thermal expansion and magnetostriction proposed in this application has a simple structure, and can not only measure the thermal expansion and magnetostriction of non-rigid materials (such as van der Waals two-dimensional materials), but also measure the thermal expansion and magnetostriction of traditional rigid materials, with a wider application range. Brief Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0029] Figure 1 It is a perspective view of the device for measuring the thermal expansion and magnetostriction of two-dimensional materials in the embodiment of this application;

[0030] Figure 2 It is a front view of the device for measuring the thermal expansion and magnetostriction of two-dimensional materials in the embodiment of this application;

[0031] Figure 3 It is an inverted perspective view of the device for measuring the thermal expansion and magnetostriction of two-dimensional materials in the embodiment of this application;

[0032] Figure 4 In the embodiment of this application Figure 3 Rear view;

[0033] Figure 5 It is a three-dimensional schematic diagram of the metal shielding cover in the embodiment of this application;

[0034] Figure 6 It is a three-dimensional schematic diagram of the metal shielding cover from another perspective in the embodiment of this application;

[0035] In the figure: 1 - bracket; 2 - sample stage; 3 - capacitor plate group; 4 - position adjustment mechanism; 5 - electrode wiring groove; 6 - metal shielding cover;

[0036] 41 - position adjustment part; 42 - positioning part; 51 - first electrode wiring groove; 52 - second electrode wiring groove. Detailed Description of the Embodiments

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] By providing a device for measuring the thermal expansion and magnetostriction of two-dimensional materials, the embodiments of the present application solve the technical problem in the prior art that the thermal expansion effect and magnetostriction effect of samples with poor rigidity cannot be measured, and achieve the purpose of measuring the thermal expansion and magnetostriction of various materials including van der Waals two-dimensional materials without relying on the rigidity of the sample itself.

[0039] The overall idea of the technical solutions in the embodiments of the present application to solve the above technical problems is as follows:

[0040] To solve the above-mentioned problems, a new device for measuring thermal expansion and magnetostriction based on the capacitance method proposed in the present application mainly includes two capacitor plates that form a parallel plate capacitor on the same side of the sample. When the size of the sample changes under the action of a magnetic field or a temperature field, the position between the two capacitor plates will change relatively, thereby causing a change in the capacitance value. Based on the specific relationship between the capacitance value and the distance between the two capacitor plates, the thermal expansion and magnetostriction of the sample can be measured. This device does not need to rely on the rigidity of the sample itself and is applicable to the thermal expansion and magnetostriction measurements of non-rigid materials (such as van der Waals two-dimensional materials) and traditional rigid materials.

[0041] To better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0042] Embodiment 1:

[0043] As Figure 1 shown, a device for measuring the thermal expansion and magnetostriction of two-dimensional materials proposed in the embodiments of the present application includes: a bracket 1; a sample stage 2 provided on the bracket 1 for carrying the sample to be measured; and a capacitor plate group 3 provided on the same side of the sample to be measured. One capacitor plate in the capacitor plate group 3 is provided at one end of the sample to be measured, and the other capacitor plate is provided on the bracket 1. The two capacitor plates form a parallel plate capacitor.

[0044] In one embodiment, the bracket 1 is in an inverted "L" shape as a whole. Refer to Figure 1-2, one side of the sample to be measured is adhesively fixed to the sample stage 2 with low-temperature glue. On the other side of the sample to be measured (i.e., the end far from the low-temperature glue adhesion) and the top of the bracket 1, a set of metal capacitor plates are provided, and a parallel-plate capacitor is formed between this set of metal capacitor plates. The capacitance value of this parallel-plate capacitor can be expressed by the formula:

[0045] ,

[0046] Among them, C represents the capacitance value of the capacitor plates (capacitance); S represents the facing area of the two plates of the parallel-plate capacitor; d represents the distance between the two plates; represents the dielectric constant of the medium.

[0047] When other parameters are fixed, the capacitance value of the parallel-plate capacitor is inversely proportional to the distance between the two capacitor plates. Therefore, under the action of a magnetic field or a temperature field, if the size of the sample to be measured changes, the position of the capacitor plate adhered to one end of the sample to be measured in this parallel-plate capacitor will change relatively, thereby causing a change in the capacitance value of the parallel-plate capacitor. Based on this, by detecting the capacitance value of the capacitor plates, the corresponding size change of the sample can be obtained.

[0048] In one embodiment, referring to Figure 1-4 , the sample stage 2 and the above-mentioned bracket 1 are movably connected through a position adjustment mechanism 4. It should be noted that by using the position adjustment mechanism 4 to realize the movable connection between the sample stage 2 and the bracket 1, the position adjustment of the sample stage 2 on the bracket 1 along the direction parallel to the spacing between the capacitor plate groups 3 can be realized, and further the thermal expansion and magnetostriction measurement of samples to be measured with different sizes can be realized.

[0049] In a preferred embodiment, the position adjustment mechanism 4 includes a position adjustment portion 41 opened on the bracket 1 and parallel to the direction of the spacing between the capacitor plate groups, and a positioning portion 42. In specific implementation, the positioning portion 42 passes through the position adjustment portion 41 and is connected to the structure on the sample stage 2 near the bracket 1 side that is pre-opened for positioning with the cooperation positioning portion 42, so as to realize the adjustment and fixation of the position of the sample stage 2. Of course, in specific implementation, the above-mentioned position adjustment mechanism 4, position adjustment portion 41, and positioning portion 42 are not specifically limited, as long as they can realize the function of adjusting and fixing the position of the sample stage 2 along the direction parallel to the spacing between the capacitor plate groups 3. For example, in a preferred embodiment, as Figure 4As shown, the position adjustment part 41 is a through groove formed in the bracket 1 along the direction parallel to the spacing between the capacitor plate groups, the positioning part 42 is a fastening screw, and screw holes for screwing and positioning are pre-formed on one side of the sample stage 2 close to the bracket 1. When the screw is not tightened, the fastening screw can slide up and down in the through groove along the direction of the spacing between the capacitor plate groups to adjust the position of the sample stage 2; when the sample stage 2 moves to the expected position, the fastening screw can be screwed into the screw hole for position fixing.

[0050] In addition, the position adjustment part 41 can also be a plurality of through holes or screw holes formed in the bracket 1 at equal intervals along the direction parallel to the spacing between the capacitor plate groups. Correspondingly, the positioning part 42 can be a positioning screw or a positioning pin, etc. Structures for positioning that are pre-formed on one side of the sample stage 2 close to the bracket 1 and adapted to the positioning part 42 can be through holes or screw holes, etc.

[0051] In one embodiment, the above-mentioned bracket 1, sample stage 2, and position adjustment mechanism 4 are all non-magnetic metal materials. It should be noted that since accessories such as the bracket 1 are all non-magnetic metal materials, the background signal during measurement can be ensured to be small enough, effectively reducing the influence of external signals on the measurement. In specific implementation, the non-magnetic metal material is not specifically limited, as long as the background signal during measurement is small enough and does not affect the measurement result. For example, it can be non-magnetic steel, aluminum and aluminum alloys, copper and copper alloys, titanium and titanium alloys, precious metals, etc.

[0052] In one embodiment, the capacitor plate is made of copper foil. Of course, in specific implementation, the material of the capacitor plate is not overly limited, as long as it does not affect the measurement of material thermal expansion and magnetostriction. The material of the capacitor plate includes but is not limited to copper foil. For example, it can also be aluminum foil, tantalum foil, metallized film, etc.

[0053] In one embodiment, the measurement device further includes an electrode wiring groove 5, which is used to accommodate the electrode wire led out from the capacitor plate electrode.

[0054] In a preferred embodiment, see Figure 1 and Figure 3 , the electrode wiring groove 5 includes a second electrode wiring groove 52 formed on the top surface of the bracket 1, which is used to accommodate the electrode wire led out from the capacitor plate electrode at the top of the bracket 1; it also includes a first electrode wiring groove 51 (not shown in the figure) for accommodating the electrode wire led out from the capacitor plate electrode on the other side of the sample to be measured.

[0055] In a preferred embodiment, the first electrode wiring groove 51 is integrally provided with the position adjustment part 41 of the above-mentioned position adjustment mechanism 4, that is, the first electrode wiring groove 51 shares the position adjustment part 41 of the above-mentioned position adjustment mechanism 4.

[0056] In a further embodiment, the measuring device further includes a measuring rod. The above-mentioned measuring device is arranged on the measuring rod, and the two capacitor plates are connected to the measuring wire on the measuring rod through electrode wires. Specifically, when implementing, the above-mentioned measuring device is fixed to the bottom of the measuring rod (sample rod) by cryogenic glue.

[0057] It should be noted that if the electrode wires are too close, capacitance plate signals will also be generated. In this embodiment, the two electrode wires are completely separated to ensure the accuracy of the measurement signal as much as possible.

[0058] In addition, it should be noted that when actually applying the device for measuring thermal expansion and magnetostriction of two-dimensional materials proposed in the embodiments of the present application to measure the thermal expansion and magnetostriction of a sample, since all materials themselves will expand and contract due to temperature changes and there will be dimensional changes, that is, there will be a background signal. Therefore, in actual implementation, the background signal of this device will be measured first, and then after measuring the signal of the sample, the background signal will be deducted to obtain the accurate signal of the sample, thereby ensuring the accuracy of the measurement of the thermal expansion and magnetostriction of the sample.

[0059] Embodiment 2:

[0060] Since the size of the measuring device of the present application is small (11mm x 8mm x 7mm, where x represents the multiplication sign), in actual implementation, in order to facilitate the installation of the sample to be measured and the making of electrodes, there is no metal shielding structure in some spaces of the measuring device proposed in the above-mentioned Embodiment 1 and its preferred embodiments. However, this will be affected by external measurement noise. The measuring device proposed in this embodiment is based on the device for measuring thermal expansion and magnetostriction of two-dimensional materials in Embodiment 1 and its preferred implementation manners, and further sets a metal shielding cover 6. The metal shielding cover 6 is used to reduce the noise that affects the measurement result generated by external electromagnetic waves.

[0061] The specific structure, shape, size, etc. of the metal shielding cover 6 are not specifically limited, as long as it can reduce the measurement noise brought by external electromagnetic waves and adapt to the specific measurement environment. For example, in a preferred embodiment, the metal shielding cover 6 is a metal shell that can be detachably connected to the bracket 1. After the sample is installed, the shell is installed to further reduce noise, specifically as Figure 5-6 shown. In other embodiments, the metal shielding cover 6 can also be metal foils such as tin foil and aluminum foil wrapped around the periphery of the above-mentioned measuring device, as long as it can reduce the measurement noise brought by external electromagnetic waves and does not affect the routing of the measuring wire.

[0062] In summary, compared with the prior art, the following beneficial effects are achieved:

[0063] 1. The device for measuring the thermal expansion and magnetostriction of two-dimensional materials proposed in this application includes: a bracket; a sample stage disposed on the bracket for carrying a sample to be measured; and a group of capacitor plates disposed on the same side of the sample to be measured, and the group of capacitor plates form a parallel-plate capacitor. The device for measuring the thermal expansion and magnetostriction proposed in this application has a simple structure and can not only measure the thermal expansion and magnetostriction of non-rigid materials (such as van der Waals two-dimensional materials), but also measure the thermal expansion and magnetostriction of traditional rigid materials, with a wider application range.

[0064] 2. For the device for measuring the thermal expansion and magnetostriction of two-dimensional materials proposed in this application, the design of the metal frame and the electrode wiring position can effectively reduce the appearance of signals from non-samples to be measured, with less measurement noise and more accurate measurement results.

[0065] 3. The device for measuring the thermal expansion and magnetostriction of two-dimensional materials proposed in this application has a small size (11mm x 8mm x 7mm, where x represents the multiplication sign), can meet the size requirements of the vast majority of magnet measurement platforms, is adaptable to the vast majority of measurement platforms, and has high compatibility.

[0066] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for measuring the thermal expansion and magnetostriction of two-dimensional materials, characterized in that The device includes: a bracket (1); a sample stage (2) arranged on the bracket (1) for carrying a sample to be measured; and a capacitor plate group (3) arranged on the same side of the sample to be measured; wherein, one capacitor plate in the capacitor plate group (3) is arranged at one end of the sample to be measured, and the other capacitor plate is arranged on the bracket (1), and the two capacitor plates form a parallel-plate capacitor; The measuring device further includes a metal shielding cover (6), and the metal shielding cover (6) is used to reduce external measurement noise; The two-dimensional material is a non-rigid van der Waals two-dimensional material; The size of the device is 11mm x 8mm x 7mm.

2. The measuring device according to claim 1, characterized in that, The bracket (1) is in an inverted "L" shape.

3. The measuring device according to claim 1, characterized in that, The sample stage (2) is movably connected to the bracket (1) through a position adjusting mechanism (4).

4. The measuring device according to claim 3, characterized in that, The position adjusting mechanism (4) includes a position adjusting part (41) opened on the bracket (1) and parallel to the spacing direction between the capacitor plate groups (3), and a positioning part (42) detachably connected to the position adjusting part (41).

5. The measuring device according to claim 3, characterized in that, The bracket (1), the sample stage (2), and the position adjusting mechanism (4) are all made of non-magnetic metal materials.

6. The measuring device according to claim 1, characterized in that, The capacitor plate includes copper foil.

7. The measuring device according to claim 6, characterized in that, The measuring device further includes: an electrode wire groove (5), and the electrode wire groove (5) is used to accommodate the electrode wire led out from the electrode of the capacitor plate; The electrode wire groove (5) includes a first electrode wire groove (51) and a second electrode wire groove (52); wherein, the second electrode wire groove (52) is opened on the top surface of the bracket (1) and is used to accommodate the electrode wire led out from the electrode of the capacitor plate at the top end of the bracket (1), and the first electrode wire groove (51) is used to accommodate the electrode wire led out from the electrode of the capacitor plate on the other side of the sample to be measured.

8. The measuring device according to claim 7, characterized in that, The first electrode wire groove (51) is integrally provided with the position adjusting part (41) of the position adjusting mechanism (4).

9. The measuring device according to any one of claims 1-8, characterized in that, The measuring device further includes: a measuring rod, the measuring device is fixed on the measuring rod, and the electrode wire is connected to the measuring wire on the measuring rod.

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