Sample head and transmission electron microscope sample rod

Abstract

The invention relates to a sample head and a transmission electron microscope sample rod, and belongs to the technical field of transmission electron microscope accessories, the sample head is in a flat plate shape, and the sample head comprises a sample loading section and a positioning section; the sample loading section is provided with a sample loading through hole for placing a carrying net, a fixed pressing sheet is arranged above the sample loading through hole, the connecting end of the fixed pressing sheet is connected with the sample loading section through a fixing piece, and the free end of the fixed pressing sheet is provided with a pressing sheet through hole matched with the sample loading through hole in shape; the positioning section is provided with a hanging hole used for being connected with a rod body of the sample rod. The technical problems that in the prior art, the tilting angle is limited, and the requirement for three-dimensional characterization is difficult to meet can be solved.

Description

Technical Field

[0001] This invention belongs to the technical field of transmission electron microscope accessories, specifically relating to a sample head and a transmission electron microscope sample holder. Background Technology

[0002] In recent years, with the deepening of nanoscience research, the crucial role of transmission electron microscopy (TEM) in material structure characterization has become increasingly prominent. As the core component supporting the sample, the sample holder is responsible for fixing the sample to be measured to the sample head and works in conjunction with the goniometer stage to achieve precise sample positioning and observation. Acquiring TEM data with a large range of rotation angles has become an important research direction for expanding the capabilities of TEM. For example, in three-dimensional electron diffraction technology and electron tomography reconstruction, it is necessary to acquire electron diffraction patterns or morphological images covering a large tilt range. These data provide indispensable technical support for resolving micro / nano crystal structures and reconstructing the three-dimensional morphology of samples.

[0003] Currently, commonly used sample rods are mainly divided into two types: single-tilt and double-tilt. The single-tilt sample rod can only tilt and rotate around one axis of the goniometer stage. Due to limitations in its mechanical structure, especially the spatial interference between the sample head and the rod body, its maximum tilt angle is usually significantly restricted. Taking standard single-tilt sample rods produced by manufacturers such as JEOL as an example, their tilt range is generally no more than ±35°, which is insufficient to meet the requirements of 3D characterization technology for large-angle data acquisition, severely limiting the application and development of high-precision 3D structural analysis. Summary of the Invention

[0004] To address the shortcomings of existing technologies, a sample head and transmission electron microscope sample rod are proposed to solve the technical problem that existing technologies have limited tilt angles and cannot meet the requirements of three-dimensional characterization.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The first aspect provides a sample head configured as a flat plate, which includes a sample loading section and a positioning section; The sample loading section is provided with a sample loading through hole for placing a carrier net. A fixing plate is provided above the sample loading through hole. The connecting end of the fixing plate is connected to the sample loading section through a fixing member. The free end of the fixing plate is provided with a pressing plate through hole that matches the shape of the sample loading through hole. The positioning section is provided with a hook hole for connecting to the rod body of the sample rod.

[0006] The technical solution is further configured such that the fixing pressure plate is configured as a bent structure, with its middle part arching upward to form a supporting ridge, and its two ends bending downward to form pressure feet for contact.

[0007] The technical solution is further configured such that the sample loading section is provided with a receiving groove, the rear end of the fixing plate is located outside the receiving groove and is connected to the sample loading section through a fixing member, and the front end of the fixing plate is located inside the receiving groove and extends above the sample loading through hole.

[0008] The technical solution is further configured such that the width of the front end of the sample loading section is smaller than the width of its rear end, and its rear end is connected to the positioning section.

[0009] The technical solution is further configured such that a gap is left between the front end of the fixed pressure plate and the front end of the sample loading section.

[0010] The technical solution is further configured such that the width of the positioning segment is greater than the width of the sample loading segment, and the junction of the two is transitioned by a slope.

[0011] The technical solution is further configured such that the width of the positioning segment is equal to the width of the sample loading segment, and the two protrude in opposite directions at their junction to form a connecting segment.

[0012] The second aspect provides a transmission electron microscope sample holder, including a handle, a rod body, and a sample head connected in sequence, wherein the sample head is located on a sample head holder, the rod body is detachably connected to the handle and the sample head respectively, and a light-blocking plate is provided on the handle.

[0013] The technical solution is further configured such that a support platform is provided at the front end of the rod, and a positioning post matching the hook hole is provided on the support platform; Above the support platform is a movable pressure plate that can move relative to the front end of the rod. The movable pressure plate opens or closes during the movement to lock the positioning column.

[0014] The technical solution is further configured such that the sample head is made of titanium shape memory alloy, the sample holder is made of epoxy resin or polyether ether ketone resin, and the light shield is made of epoxy resin, polyether ether ketone resin, or stainless steel. The beneficial effects of this invention are: 1. The flat plate structure avoids three-dimensional protrusions, reduces the overall height of the sample head, and minimizes the risk of collision with other structural components during large-angle tilting. In a transmission electron microscope (TEM), utilizing the tilting function of the TEM stage, the tilting range around the shaft can reach up to ±75 degrees. o .

[0015] 2. Align the through hole of the pressing tablet with the through hole of the sample loading tablet to ensure that only the edge is pressed and the central observation area is not blocked, thereby reducing scattering and diffraction background noise; prevent the grid from shifting or warping by setting a fixed pressing tablet, and at the same time, keep the grid flat by applying force evenly through the pressing foot.

[0016] 3. The positioning post is inserted into the mounting hole of the sample head to achieve precise and repeatable positioning; the movable pressure plate can be opened / closed to achieve a three-step installation of "insert-press-lock". After locking, a rigid connection is formed, which has strong resistance to vibration and tilting torque; different types of sample heads can be replaced as long as the mounting holes are consistent. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the transmission electron microscope sample holder in an embodiment of the present invention; Figure 2 This is a top view of the sample head in an embodiment of the present invention; Figure 3 This is a side view of the sample head in an embodiment of the present invention; Figure 4 This is a top view of another embodiment of the sample head in this invention; Figure 5 Co7V4O in the embodiments of the present invention 19 A schematic diagram of the three-dimensional reconstruction results of the sample's electron diffraction data.

[0018] In the attached diagram: 100, handle; 200, rod; 300, sample head; 400, light-blocking plate; 301. Sample loading section; 302. Positioning section; 303. Fixing plate; 304. Fixing element; 305. Receiving groove; 306. Plate through hole; 307. Hanging hole; 308. Support ridge; 309. First pressure foot; 310. Second pressure foot; 311. Sample loading through hole; 312. Connecting section; Figure 5 In the diagram, (a) is a three-dimensional reciprocal space lattice; (b)-(d) are projections of the reciprocal lattice along the directions

[010] ,

[100] and

[001] , respectively. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0020] Example 1: According to an embodiment of the present invention, a sample head is provided; please refer to [link / reference]. Figures 2 to 4 It is configured as a flat plate, which includes a sample loading section 301 and a positioning section 302.

[0021] Understandably, designing the sample head as a narrow, elongated flat plate significantly reduces its lateral width. This flat plate structure avoids three-dimensional protrusions, lowers the overall height of the sample head, and reduces the risk of collisions with other structural components during large-angle tilting. In a transmission electron microscope (TEM), utilizing the tilting function of the TEM stage, the tilting range around the shaft can reach up to ±75 degrees. o .

[0022] For the sample head in this embodiment, please refer to... Figures 2 to 4 The sample loading section 301 is an area for placing and fixing the sample. Its front end is narrower than its rear end, and its rear end connects to the positioning section 302. The sample loading section 301 is provided with a sample loading through-hole 311 for placing a mesh carrier. The mesh carrier can be made of copper mesh, carbon support film, etc. The edges of the sample loading through-hole 311 are flat and smooth to avoid damaging the mesh carrier or causing charge accumulation.

[0023] Specifically, the shape of the sample loading through-hole 311 can be designed as a circle, square or other shapes according to actual needs to adapt to different types of carriers.

[0024] For the sample head in this embodiment, please refer to... Figures 2 to 4 A fixing plate 303 is provided above the sample loading through hole 311. The fixing plate 303 is a metal sheet covering the sample loading through hole 311, used to press the carrier mesh and prevent it from falling off or drifting in a vacuum environment. The fixing member 304 firmly fixes the fixing plate 303 to the sample head.

[0025] Furthermore, the connecting end of the fixing plate 303 is connected to the sample loading section 301 via a fixing member 304. Specifically, the fixing member 304 uses a screw, which passes through a threaded hole on the fixing plate 303 to securely fix the fixing plate 303 to the sample head. This single-screw fixing method simplifies the structure and reduces the number of parts and overall volume.

[0026] For the sample head in this embodiment, please refer to... Figures 2 to 4 The fixing plate 303 is configured as a bent structure, with its middle part arching upward to form a supporting ridge 308, and its two ends bending downward to form a first pressure foot 309 and a second pressure foot 310 for contact.

[0027] Specifically, the first pressure foot 309 is used to press the carrier mesh, and the second pressure foot 310 is attached to the upper surface of the sample head.

[0028] Specifically, the fixing plate 303 is made of copper or a copper alloy.

[0029] Understandably, the fixing plate 303 is designed with a three-section structure: slightly higher in the middle and bent downwards on both sides. This structure enhances the elasticity of the fixing plate 303, allowing for even force application when tightening the fixing plate 303, avoiding localized stress concentration that could lead to the breakage of the carrier mesh. It also helps to adapt to carrier meshes of different thicknesses and improves clamping stability.

[0030] For the sample head in this embodiment, please refer to... Figures 2 to 4 The sample loading section 301 is provided with a receiving groove 305. The rear end of the fixing plate 303 is located outside the receiving groove 305 and is connected to the sample loading section 301 through the fixing member 304. The front end of the fixing plate 303 is located inside the receiving groove 305 and extends above the sample loading through hole 311 to form a pressing on the carrier mesh.

[0031] Understandably, the receiving groove 305 is used to accommodate a portion of the fixing plate 303, providing recessed space for the installation of the fixing plate 303. The depth and size of the receiving groove 305 match the dimensions of the fixing plate 303, ensuring that the fixing plate 303 can stably press down on the carrier net after installation.

[0032] For the sample head in this embodiment, please refer to... Figures 2 to 4 The free end of the fixed pressure plate 303 is provided with a pressure plate through hole 306 that matches the shape of the sample loading through hole 311. This design ensures that the sample can still be exposed in the area of ​​the pressure plate through hole 306 when the fixed pressure plate 303 presses down on the carrier mesh, which is convenient for observation and analysis.

[0033] For the sample head in this embodiment, please refer to... Figures 2 to 4 A gap is left between the front end of the fixed pressure plate 303 and the front end of the sample loading section 301. This design can reduce the risk of spatial interference and improve the safety of large-angle tilting.

[0034] For the sample head in this embodiment, please refer to... Figures 2 to 4 The positioning section 302 is used to connect the sample head to the sample rod. The positioning section 302 is provided with a mounting hole 307 for connecting to the sample rod body. The size and shape of the mounting hole 307 match the sample rod to ensure a secure connection.

[0035] For the sample head in this embodiment, please refer to... Figures 2 to 4The positioning section 302 is wider than the sample loading section 301, and the junction between them is formed by a beveled transition. This design increases the stability of the positioning section 302, while the beveled transition structure reduces stress concentration and improves the overall structural strength. The angle of the beveled transition can be designed according to actual needs, typically 30°-60°, to ensure a smooth transition while providing sufficient strength support.

[0036] For the sample head in this embodiment, please refer to... Figures 2 to 4 The width of the positioning segment 302 is equal to the width of the sample loading segment 301, and the two protrude in opposite directions at their junction to form a connecting segment 312. This design makes the overall structure more compact, while the design of the connecting segment 312 increases the strength of the connection, preventing breakage due to stress concentration during use. The protruding length of the connecting segment 312 is typically 2 / 3 to 4 / 5 of the width of the sample loading segment 301, ensuring sufficient strength without affecting the overall aesthetics and usability.

[0037] In use, the operator first places the carrier mesh on the sample loading through-hole 311, then presses down and fixes it with the fixing plate 303, thus firmly securing the carrier mesh to the sample loading through-hole 311. Because the fixing plate 303 employs a bent structure design, the downward-bent pressure feet at both ends apply uniform pressure to the carrier mesh, preventing it from moving or falling off during observation. Simultaneously, the upward-arching support ridge 308 in the middle of the fixing plate 303 increases its rigidity, ensuring it will not deform due to prolonged use. After the sample head is connected to the sample rod via the mounting hole 307 on the positioning section 302, the sample can be easily placed into the transmission electron microscope for observation and analysis. The overall flat design reduces the thickness of the sample head, and utilizing the tilting function of the transmission electron microscope's stage, the tilt range around the rod can reach up to ±75 degrees. o .

[0038] Example 2: According to an embodiment of the present invention, a transmission electron microscope sample holder is provided. Please refer to [link to relevant documentation]. Figures 1 to 4 The system includes a handle 100, a rod 200, and the aforementioned sample head 300, connected in sequence. The sample head 300 is located on a sample head holder. The rod 200 is detachably connected to both the handle 100 and the sample head 300, facilitating timely replacement and disassembly in case of damage. A light-blocking plate 400 is provided on the handle 100, which effectively blocks unnecessary electron beams and improves imaging quality.

[0039] Furthermore, the rod 200 has a slender cylindrical structure with sufficient strength and rigidity to withstand various stresses during operation while maintaining a lightweight design. The rod 200 is threadedly connected to the handle 100 for easy disassembly and installation. The other end of the rod 200 is also detachably connected to the sample head 300, facilitating the replacement of different sample heads to meet various experimental needs. The rod 200 is made of a metal material with good thermal conductivity and corrosion resistance, enabling stable operation in a vacuum environment.

[0040] Furthermore, the handle 100 and the light-blocking plate 400 are detachable. In addition, the handle 100 and the light-blocking plate 400 can also be integrally formed.

[0041] For the transmission electron microscope sample holder in this embodiment, please refer to [link / reference]. Figures 1 to 4 The front end of the rod is provided with a support platform, and the support platform is provided with a positioning post that matches the hanging hole 307; A movable pressure plate, which can move relative to the front end of the rod, is provided above the support platform. The movable pressure plate opens or closes during movement to lock the positioning post. This locking mechanism ensures a secure connection between the sample head 300 and the rod 200, preventing the sample head 300 from accidentally falling off during operation.

[0042] In use, when the movable pressure plate is in the open position, the positioning post is fully exposed and can be freely inserted into or removed from the mounting hole 307. At this time, the sample head 300 can be easily installed or removed. When locking is required, the movable pressure plate is switched to the closed position, and the front end of the movable pressure plate covers the positioning post inserted into the mounting hole 307, forming a physical barrier to prevent the positioning post from detaching from the mounting hole 307. After locking, a rigid connection is formed, providing strong resistance to vibration and tilting torque. This locking mechanism is simple, reliable, and easy to operate.

[0043] Optionally, the movable tablet can be flipped relative to the front end of the rod. This part of the structure can adopt the structure disclosed in US5225683A, which will not be described in detail here.

[0044] Furthermore, the shape of the positioning post is adapted to the mounting hole 307, allowing it to be inserted into the mounting hole 307 for positioning. The height of the positioning post is appropriate, ensuring that sufficient portion is exposed after insertion into the mounting hole 307 for easy subsequent locking operations. The positioning post can be made of metal with a rust-proof surface treatment to enhance durability. The positioning post and mounting hole 307 work together to achieve precise and repeatable positioning; different types of sample heads can be replaced as long as the mounting hole 307 is consistent.

[0045] For the transmission electron microscope sample holder in this embodiment, please refer to [link / reference]. Figures 1 to 4The sample head 300 is made of titanium shape memory alloy, a material with excellent elastic memory properties and corrosion resistance, maintaining stable physical properties even in high vacuum environments. The sample holder is made of epoxy resin or polyetheretherketone resin, materials with good insulation and mechanical strength, ensuring stability under electron beam irradiation. The light-blocking plate 400 is made of epoxy resin, polyetheretherketone resin, or stainless steel, materials that effectively block the electron beam and reduce the impact of scattered electrons on image quality.

[0046] Example 3: Three-dimensional electron diffraction data were collected using the transmission electron microscope sample holder disclosed in Example 2. Specifically, the sample used in the experiment was cobalt vanadium oxide (Co7V4O) with a known structure. 19 The space group is P63mc, and the cell parameters are a = b = 12.8655 Å, c = 5.0651 Å, α = β = 90°, γ = 120°. Here, a, b, and c represent the lattice constants of the cell, which are the side lengths of the cell in three independent, non-coplanar directions. α represents the angle between the positive directions of the b-axis and c-axis in the cell; β represents the angle between the positive directions of the a-axis and c-axis in the cell; and γ represents the angle between the positive directions of the a-axis and b-axis in the cell.

[0047] Take a small amount of powder sample and put it into a centrifuge tube. Add 2 ml of ethanol to dilute it and sonicate for 10 min. Then, use a dropper to take a small amount of liquid and drop it onto a copper grid coated with a carbon film. After the ethanol has evaporated completely, transfer the copper grid to the sample rod and collect three-dimensional electron diffraction data.

[0048] First, the goniometer stage was rotated in transmission electron microscopy (TEM) diffraction mode, with a rotation angle range of -75° to +75°. Three-dimensional electron diffraction data were collected using a crystal tracking file in diffraction mode, with an exposure time of 500 ms for each diffraction pattern, for a total of 201 diffraction images. The electron diffraction data were then reconstructed in three dimensions using REDp software, and the results are shown below. Figure 5 As shown, the final cell parameters are: a = 12.496, b = 12.456 Å, c = 4.890 Å, α = β = 90 °, γ = 120 °, which is basically consistent with the actual unit cell parameters of the sample. This also verifies the reliability of this sample rod for data collection, demonstrating the reliability and data quality assurance capability of the sample rod in real scientific research scenarios.

[0049] This embodiment demonstrates that the transmission electron microscope sample holder disclosed in this invention not only extends the tilt angle, but also achieves a usable level in terms of diffraction signal integrity, data consistency, and structural resolution accuracy at large angles.

[0050] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0052] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0053] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0054] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A sample head, characterized in that, It is configured as a flat plate, and the sample head includes a sample loading section and a positioning section; The sample loading section is provided with a sample loading through hole for placing a carrier net. A fixing plate is provided above the sample loading through hole. The connecting end of the fixing plate is connected to the sample loading section through a fixing member. The free end of the fixing plate is provided with a pressing plate through hole that matches the shape of the sample loading through hole. The positioning section is provided with a hook hole for connecting to the rod body of the sample rod.

2. A sample head according to claim 1, characterized in that, The fixing plate is configured as a bent structure, with its middle part arching upward to form a supporting ridge, and its two ends bending downward to form pressure feet for contact.

3. A sample head according to claim 2, characterized in that, The sample loading section is provided with a receiving groove. The rear end of the fixing plate is located outside the receiving groove and is connected to the sample loading section by a fixing member. The front end of the fixing plate is located inside the receiving groove and extends above the sample loading through hole.

4. A sample head according to claim 1, characterized in that, The width of the front end of the sample loading section is smaller than the width of its rear end, and its rear end is connected to the positioning section.

5. A sample head according to claim 4, characterized in that, A gap is left between the front end of the fixed pressure plate and the front end of the sample loading section.

6. A sample head according to claim 1, characterized in that, The width of the positioning section is greater than the width of the sample loading section, and the two are connected by a beveled transition.

7. A sample head according to claim 1, characterized in that, The width of the positioning segment is equal to the width of the sample loading segment, and the two segments protrude in opposite directions at their junction to form a connecting segment.

8. A transmission electron microscope sample holder, characterized in that, The device includes a handle, a rod, and a sample head as described in any one of claims 1-7, connected in sequence. The sample head is located on a sample head holder. The rod is detachably connected to the handle and the sample head, respectively. A light-blocking plate is provided on the handle.

9. The transmission electron microscope sample holder according to claim 8, characterized in that, The front end of the rod is provided with a support platform, and the support platform is provided with a positioning post that matches the hanging hole; Above the support platform is a movable pressure plate that can move relative to the front end of the rod. The movable pressure plate opens or closes during the movement to lock the positioning column.

10. The transmission electron microscope sample holder according to claim 8, characterized in that, The sample head is made of titanium shape memory alloy, the sample holder is made of epoxy resin or polyether ether ketone resin, and the light shield is made of epoxy resin, polyether ether ketone resin, or stainless steel.

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