In-situ tensile transmission electron microscope sample rod

Abstract

The invention belongs to the technical field of nano material in-situ research, discloses an in-situ tensile transmission electron microscope sample rod, and solves the technical problem that a TEM sample rod in the prior art is difficult to maintain stability while applying stress to a two-dimensional material. The sample rod comprises a rod body, the connecting rod head is arranged on the rod body; the metal bottom plate is mounted at the head of the connecting rod; the sample fixing part is arranged on the metal bottom plate, an observation window is formed in the sample fixing part, and the sample fixing part is used for applying a controllable mechanical load to a sample arranged in the observation window; the micro-displacement driver is arranged on the connecting rod head and connected with one end of the metal bottom plate, and the micro-displacement driver is electrically connected with the power supply; the two-dimensional material sample is fixed in the observation window in a non-contact manner through physical adsorption. Therefore, through the multilayer driving arrangement of the metal bottom plate, the sample fixing part and the micro-displacement driver, when the tensile strain with sub-nano precision is applied to the two-dimensional material sample, the two-dimensional material sample is more stable, and the controllability is higher.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of in-situ research of nanomaterials, and particularly relates to an in-situ tensile transmission electron microscope sample rod. BACKGROUND

[0002] Transmission electron microscope (TEM) is widely used in the fields of material science and life science as an important microstructure characterization method, and is well known for high resolution. In existing research, although certain achievements have been made on the electronic properties and basic mechanical properties of two-dimensional materials such as MoS2 and graphene nanosheet, the specific mechanical behavior of the two-dimensional materials in practical application scenarios, especially the dynamic response mechanism under complex loading process, is still relatively scarce. The dynamic atomic scale response of the two-dimensional materials under controllable and continuous tensile load still faces great challenges. Traditional bulk TEM samples or commercial in-situ sample rods are mainly designed for three-dimensional materials, and the loading mode (such as compression and bending) and sample fixing technology (such as welding and gluing) are extremely unsuitable for ultra-thin and fragile two-dimensional materials, so that effective in-plane tensile cannot be achieved.

[0003] At present, the general TEM in-situ technology still has the problem of applying stress to the two-dimensional materials while maintaining stability, which is particularly manifested in the two-dimensional materials as follows: the probe compression method can only apply off-plane load and cannot achieve the required in-plane strain state; the "push-pull" chip based on micro-electro-mechanical system (MEMS) can achieve in-plane tensile, but its structure is complex, and under electron beam irradiation, thermal drift and electrical interference are easily generated, resulting in poor imaging stability and difficulty in maintaining atomic resolution for a long time; the existing technology generally uses mechanical clamping or solid-liquid adhesive to fix the sample, which is easy to introduce initial stress, pollution or damage to the two-dimensional materials themselves, and affect the observation of intrinsic mechanical behavior. Therefore, developing a special sample rod that can stably, precisely and in-plane tensile the two-dimensional materials and is compatible with high-resolution TEM imaging is the key to revealing the nanomechanical behavior of the two-dimensional materials. SUMMARY

[0004] The present application aims at the above-mentioned deficiencies in the prior art, and provides an in-situ tensile transmission electron microscope sample rod to solve the technical problem that the TEM sample rod in the prior art is difficult to apply stress to the two-dimensional materials while maintaining stability.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: An in-situ tensile transmission electron microscope sample rod, comprising: a rod body; a connecting rod head arranged at one end of the rod body; a metal base plate detachably installed on the connecting rod head; A sample fixing part is arranged on the metal base plate, and the sample fixing part is provided with an observation window for electron beam transmission and sample bearing, and the sample fixing part is used for applying controllable mechanical load to a sample arranged in the observation window. A micro-displacement driver is arranged at the connecting rod head and connected with one end of the metal base plate, and the micro-displacement driver is electrically connected with a power supply. A two-dimensional material sample is fixed in the observation window by physical adsorption in a non-contact manner.

[0006] Further, the metal base plate is a base titanium alloy plate, and a U-shaped groove is arranged on the metal base plate.

[0007] Further, the side wall of the connecting rod head has a mounting surface, and the metal base plate is mounted on the mounting surface by screws.

[0008] Further, the sample fixing part comprises a silicon-based micro-window chip.

[0009] Further, the silicon-based micro-window chip is fixed on the metal base plate by silver paste.

[0010] Further, the length and width of the observation window are 100 mu m and 10 mu m, respectively.

[0011] Further, the micro-displacement driver is a piezoelectric ceramic driver, which is used to drive the two-dimensional material sample to displace with nanometer-level precision.

[0012] Further, a controller is further arranged and electrically connected with the piezoelectric ceramic driver.

[0013] Further, the two-dimensional material sample is fixed in the observation window by a van der Waals force adsorption method.

[0014] Further, the two-dimensional material sample is MoS2.

[0015] The in-situ tensile transmission electron microscope sample rod provided by the application has the following beneficial effects: 1. By arranging the metal base plate, the silicon-based micro-window chip and the piezoelectric ceramic driver in multiple layers, the tensile strain applied to the two-dimensional material sample is more stable and controllable.

[0016] 2. By using the van der Waals force transfer method to adsorb and fix the two-dimensional material sample, the initial stress and pollution are avoided, the probability of damaging the two-dimensional material itself is reduced, and the probability of affecting the observation of intrinsic mechanical behavior is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The structure diagram of the in-situ tensile transmission electron microscope sample rod provided by the embodiment of the application is shown.

[0018] Markings in the drawings and corresponding component names: 1-rod body, 2-connection rod head, 21-mounting surface, 3-metal base plate, 31-U-shaped groove, 4-silicon-based micro-window chip, 41-observation window, 5-micro-displacement driver, 6-two-dimensional material sample. DETAILED DESCRIPTION

[0019] The specific embodiments of the present application are described below to facilitate the understanding of the present application by those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all inventions utilizing the concept of the present application are within the scope of protection.

[0020] The in-situ tensile transmission electron microscope sample rod provided by the embodiment is used to solve the technical problem that the TEM sample rod in the prior art is difficult to apply stress to the two-dimensional material while maintaining stability. The in-situ tensile transmission electron microscope sample rod includes a rod body 1, a connection rod head 2, a metal base plate 3, a sample fixing part, a micro-displacement driver 5, and a two-dimensional material sample 6, wherein: Reference Figure 1 The rod body 1 is a hollow circular rod.

[0021] The connection rod head 2 is arranged at one end of the rod body 1. Optionally, the connection rod head 2 is detachably mounted at one end of the rod body 1. Optionally, the connection rod head 2 is connected to one end of the rod body 1 by a bolt. Optionally, the connection rod head 2 includes a connecting part and a mounting part. The connecting part is a short circular rod, which is detachably connected to one end of the rod body 1. The mounting part is a plate body, one end of which is fixedly mounted at one end of the short circular rod away from the rod body 1. It should be noted that the plate body can be connected to the short circular rod by welding, bonding or heat staking, of course, it can also be integrally formed.

[0022] The metal base plate 3 is detachably mounted on the connection rod head 2, that is, the metal base plate 3 is detachably mounted on the plate body. In this way, the detachable metal base plate 3 is more convenient for disassembly and replacement. The metal base plate 3 is a primary strain amplification and transmission element.

[0023] The sample fixing part is arranged on the metal base plate 3, and the sample fixing part is provided with an observation window 41 for electron beam transmission and sample bearing. Optionally, the observation window 41 is transparent. The sample fixing part is used to apply a controllable mechanical load to the sample placed in the observation window 41. The sample fixing part is a secondary strain amplification and transmission element.

[0024] The micro-displacement driver 5 is arranged at the connecting rod head 2 and is connected with one end of the metal base plate 3, and the micro-displacement driver 5 is electrically connected with a power supply, so that the tensile stress is provided through the arrangement of the micro-displacement driver 5.

[0025] The two-dimensional material sample 6 is fixed in the observation window 41 by physical adsorption, so that the initial stress and pollution are avoided, and the probability of damaging the two-dimensional material itself is reduced, thereby reducing the probability of affecting the observation of the intrinsic mechanical behavior.

[0026] Optionally, the two-dimensional material sample 6 is fixed in the observation window 41 by physical adsorption.

[0027] When the in-situ tensile transmission electron microscope sample rod provided by the application is used, the sample is prepared and installed, and the specific steps are as follows: a few-layer two-dimensional material nanosheet is obtained by a mechanical exfoliation method, and then the two-dimensional material nanosheet is transferred to a flexible polymer substrate with a micropore array by a dry transfer method, under an optical microscope, the two-dimensional material nanosheet is aligned with the observation window 41 of the sample fixing part, the two-dimensional material nanosheet is attached to the observation window 41 by physical adsorption, then the sample fixing part loaded with the two-dimensional material nanosheet is fixed on the metal base plate 3, finally, the connecting rod head 2 is placed in a vacuum environment, a micro-negative pressure is applied to the observation window 41, so that the two-dimensional material nanosheet is firmly adsorbed, the preparation and installation of the sample are completed, then the assembled sample rod is inserted into a transmission electron microscope sample stage, after a clear low-magnification image of the sample is obtained, the region of interest is moved to the center of the field of view, the control program is started, the tensile parameters (such as target strain, step length, strain rate) are set, then the control end sends instructions to the voltage controller according to the setting, drives the piezoelectric ceramic to slowly elongate, and pushes the metal base plate 3 to elastically bend, so that the sample fixing part arranged on the metal base plate 3 deforms, and finally the tensile strain is transmitted to the two-dimensional material sample 6 adsorbed in the observation window 41, in this process, TEM images or videos are continuously collected, and a series of dynamic structural information such as atomic lattice, dislocation movement, crack initiation and expansion are recorded. After the experiment is completed, the program can control the voltage to change reversely, so that the piezoelectric ceramic contracts, and the sample (if not broken) can relax. Therefore, in combination with a high-resolution transmission electron microscope, the in-situ tensile transmission electron microscope sample rod provided by the application can observe the atomic-scale structural evolution, crack propagation and ductile fracture mechanism of the two-dimensional material under the tensile condition in real time, and provides a new experimental method for the intrinsic mechanical property research of the two-dimensional material.

[0028] The metal base plate 3 is a titanium alloy base plate. Optionally, the metal base plate 3 is precision milled from titanium alloy. A U-shaped groove 31 is provided on the metal base plate 3. The U-shaped groove 31 provides a deformation framework for sample deformation. The titanium alloy base plate is selected as the structure for primary strain amplification and transmission. The titanium alloy base plate has high strength, low weight, excellent elasticity and good machinability. It can achieve predictable and repeatable elastic deformation and has a long fatigue life.

[0029] The side wall of the connecting rod head 2 has a mounting surface 21. The metal base plate 3 is mounted on the mounting surface 21 by screws, that is, the metal base plate 3 is mounted on the plate body by screws. In this way, the metal base plate 3 connected by screws is easy to disassemble and replace.

[0030] Optionally, the sample fixing part includes a silicon-based microwindow chip 4, and the observation window 41 is disposed on the silicon-based microwindow chip 4. Optionally, the observation window 41 is fabricated on a double-sided polished silicon wafer with a thickness of 0.5 mm using standard semiconductor processes, through photolithography and deep reactive ion etching technology.

[0031] Optionally, the silicon-based microwindow chip 4 is fixed to the metal substrate 3 with silver paste. Specifically, the silicon-based microwindow chip 4 is bonded to the central flat area of ​​the substrate titanium alloy plate with highly conductive silver paste. In this way, the silicon-based microwindow chip 4 is firmly bonded to the substrate titanium alloy plate through silver paste, a kind of conductive adhesive with good rigidity, thereby transferring the mechanical deformation of the substrate titanium alloy plate to the surface of the silicon-based microwindow chip 4 without loss or slippage.

[0032] Optionally, the length and width of the observation window 41 are 100 μm and 10 μm, respectively.

[0033] The actuator is a piezoelectric ceramic actuator, used to drive the two-dimensional material sample 6 to perform nanometer-level precision displacement. The piezoelectric ceramic actuator is of the shear type or stack type, with its tail fixed in the connecting rod head 2 and its head in close contact with the free end of the substrate titanium alloy plate.

[0034] It also includes a controller electrically connected to the piezoelectric ceramic actuator. Specifically, the piezoelectric ceramic actuator is connected via wires to a voltage controller located at the tail of rod 1. This voltage controller can be programmed and controlled by a control terminal, with a voltage output range of 0-150V and an accuracy of 0.001V. This allows for the control of the tensile step size (0.1nm) and strain rate (range from static (0.1% s)). -1 ) to high-speed loading (10 4 s -1 The controllability of )).

[0035] Optionally, the two-dimensional material sample 6 is MoS2. Molybdenum disulfide was chosen as the two-dimensional material sample 6. Molybdenum dioxide has a typical layered structure, with strong covalent / ionic bonds within the layers and weaker van der Waals forces connecting the layers. This structure allows it to be peeled or grown into two-dimensional sheets with atomic-level thickness, making it an ideal model system for studying the mechanical and electrical behavior of two-dimensional materials. Furthermore, the smooth layered surface of molybdenum dioxide generates uniform and sufficient van der Waals forces, enabling it to stably adsorb onto the silicon-based microwindow chip 4 without slippage during stretching.

[0036] Although specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by a person skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. An in-situ tensile transmission electron microscope sample holder, characterized in that, include: Rod (1); A connecting rod head (2) is disposed at one end of the rod body (1); A metal base plate (3) is detachably mounted on the connecting rod head (2); The sample fixing part is provided on the metal base plate (3), and the sample fixing part is provided with an observation window (41) for electron beam transmission and sample carrying. The sample fixing part is used to apply a controllable mechanical load to the sample placed in the observation window (41). A micro-displacement actuator (5) is disposed on the connecting rod head (2) and connected to one end of the metal base plate (3), and the micro-displacement actuator (5) is electrically connected to a power source; Two-dimensional material sample (6) is fixed in the observation window (41) non-contactly by physical adsorption.

2. The in-situ tensile transmission electron microscope sample holder according to claim 1, characterized in that, The metal base plate (3) is a titanium alloy base plate, and a U-shaped groove (31) is provided on the metal base plate (3).

3. The in-situ tensile transmission electron microscope sample holder according to claim 2, characterized in that, The side wall of the connecting rod head (2) has a mounting surface (21), and the metal base plate (3) is mounted on the mounting surface (21) by screws.

4. The in-situ tensile transmission electron microscope sample holder according to claim 1, characterized in that, The sample fixing part includes a silicon-based microwindow chip (4).

5. The in-situ tensile transmission electron microscope sample holder according to claim 4, characterized in that, The silicon-based microwindow chip (4) is fixed on the metal substrate (3) by silver paste.

6. The in-situ stretching transmission electron microscope sample holder according to claim 5, characterized in that, The length and width of the observation window (41) are 100 μm and 10 μm, respectively.

7. The in-situ tensile transmission electron microscope sample holder according to claim 1, characterized in that, The micro-displacement actuator (5) is a piezoelectric ceramic actuator used to drive the two-dimensional material sample (6) to perform nanometer-level precision displacement.

8. The in-situ tensile transmission electron microscope sample holder according to claim 7, characterized in that, It also includes a controller, which is electrically connected to the piezoelectric ceramic driver.

9. The in-situ tensile transmission electron microscope sample holder according to claim 1, characterized in that, The two-dimensional material sample (6) is fixed in the observation window (41) by van der Waals force adsorption.

10. The in-situ tensile transmission electron microscope sample holder according to any one of claims 1-9, characterized in that, The two-dimensional material sample (6) is MoS2.

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