A transmission electron microscope sample holder ring and method of testing thereof

Abstract

This invention relates to a transmission electron microscope (TEM) sample clamping ring and its testing method, belonging to the field of TEM technology in the metallurgical industry. The technical solution comprises an upper ring (1), a lower ring (2), and a hemisphere (3). Both the upper ring (1) and the lower ring (2) are double-ring structures composed of an outer ring (4) and an inner ring (5). The outer ring (4) and the inner ring (5) are connected together by a connecting beam (6). The outer ring (4) of both the upper ring (1) and the lower ring (2) is provided with mutually cooperating hemispheres (3). At least one of the hemispheres (3) on the outer ring (4) of the upper ring (1) and the outer ring (4) of the lower ring (2) is a hollow structure. The inner diameter of the inner ring (5) of both the upper ring (1) and the lower ring (2) is less than 1 mm. The beneficial effect of this invention is that it minimizes the sample size based on electrolytic double-spraying of samples, thereby reducing the interference of the inherent magnetism of magnetic materials on TEM imaging.

Description

Technical Field

[0001] This invention relates to a sample clamping ring for transmission electron microscopy and its testing method, belonging to the field of transmission electron microscopy technology in the metallurgical industry. Background Technology

[0002] Transmission electron microscopy (TEM) is a high-resolution imaging tool that uses a high-energy electron beam to penetrate a sample and image it through electromagnetic lenses to observe the sample's microstructure. It is widely used in materials science, nanotechnology, and biology. However, when analyzing magnetic materials, the material's inherent magnetism can cause electron beam deflection or phase interference, thus reducing image quality. Furthermore, the material's magnetism can limit the sample tilt angle in electron diffraction analysis, significantly reducing the sample's applicability.

[0003] Traditional TEM sample preparation methods typically process samples into thin slices with a diameter of 3 mm. However, larger sample sizes increase the overall magnetic moment of the material, thereby enhancing magnetic interference. On the other hand, when the sample size is reduced, traditional clamping devices struggle to provide stable clamping for small samples, leading to issues such as sample detachment and positional shift, which negatively impact TEM observation results. Summary of the Invention

[0004] The purpose of this invention is to provide a transmission electron microscope (TEM) sample clamping ring and its testing method, which minimizes the sample size based on electrolytic double-jet sample preparation, thereby reducing the interference of the inherent magnetism of magnetic materials on TEM imaging and solving the problems existing in the background art.

[0005] The technical solution of this invention is: A transmission electron microscope sample clamping ring includes an upper ring, a lower ring, and a hemisphere. Both the upper and lower rings are double-ring structures composed of an outer ring and an inner ring, which are connected together by a connecting beam. The outer rings of the upper and lower rings are respectively provided with mutually cooperating hemispheres, and the hemispheres in the upper ring or the lower ring are hollow structures.

[0006] The inner ring diameters of the upper and lower rings are matched to the size of the transmission electron microscope sample.

[0007] The inner diameter of the inner ring in the upper and lower rings is less than 1 mm.

[0008] The thickness of both the upper and lower rings is 0.05~0.1mm. The hemisphere in the upper ring is a hollow hemisphere, which is attached to the hemisphere in the lower ring.

[0009] A method for testing samples using transmission electron microscopy includes the following steps: Step 1: Prepare a standard 3mm transmission sample from the magnetic material to be tested by electrolytic double spraying; Step 2: Cut the prepared transmission sample into small-sized samples with a diameter greater than 1 mm; Step 3: Place the small sample in the center of the inner ring of the lower ring, and then place the upper ring on the lower ring so that the hemispheres in the upper ring and the lower ring are engaged together; Step 4: Install the clamping ring with the sample loaded onto the transmission electron microscope sample rod and send it into the vacuum chamber of the transmission electron microscope for testing.

[0010] In step two, the prepared transmission sample is cut into a small circular or near-circular sample with a diameter greater than 1 mm centered on the hole.

[0011] In step two, the diameter of the small sample is 1~2mm.

[0012] The beneficial effects of this invention are: it can stably hold small-sized transmission electron microscope (TEM) samples, greatly reducing the interference of the inherent magnetism of magnetic materials on TEM imaging, solving the problem of limited tilt angle of magnetic materials in TEM analysis, and improving the detection efficiency of TEM. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 Top view; Figure 3 for Figure 1 The front view; Figure 4 The detection results are from an embodiment of the present invention; Figure 5 The test results are for the comparative examples of this invention; In the diagram: 1. Upper ring; 2. Lower ring; 3. Hemisphere; 4. Outer ring; 5. Inner ring; 6. Connecting beam; 7. Hollow hemisphere; 8. Solid hemisphere. Detailed Implementation

[0014] The invention will be further described below with reference to the accompanying drawings and examples.

[0015] See attached document Figure 1-5 A transmission electron microscope sample holding ring includes an upper ring 1, a lower ring 2, and a hemisphere 3. The upper ring 1 and the lower ring 2 are both double-ring structures composed of an outer ring 4 and an inner ring 5. The outer ring 4 and the inner ring 5 are connected together by a connecting beam 6. The outer ring 4 of the upper ring 1 and the lower ring 2 are respectively provided with mutually cooperating hemispheres 3. The hemisphere 3 in the upper ring 1 or the hemisphere 3 in the lower ring 2 is a hollow structure.

[0016] A method for testing samples using transmission electron microscopy includes the following steps: Step 1: Prepare a standard 3mm transmission sample from the magnetic material to be tested by electrolytic double spraying; Step 2: Cut the prepared transmission sample into small-sized samples with a diameter greater than 1 mm; Step 3: Place the small sample in the center of the inner ring 4 in the lower ring 2, and then place the upper ring 1 on the lower ring 2 so that the hemisphere 3 in the upper ring 1 and the hemisphere 3 in the lower ring 2 are fastened together. Step 4: Install the clamping ring with the sample loaded onto the transmission electron microscope sample rod and send it into the vacuum chamber of the transmission electron microscope for testing.

[0017] In this embodiment, refer to the appendix Figure 1-5 The sample holder ring for the transmission electron microscope is made of copper, nickel, molybdenum, aluminum, tungsten, or their alloys. It includes an upper ring 1, a lower ring 2, a hemisphere 3, an outer ring 4, an inner ring 5, a connecting beam 6, a hollow hemisphere 7, and a solid hemisphere 8, wherein: The thickness of the upper ring 1 and the lower ring 2 is 0.05~0.1mm. The outer diameter of the outer ring 4 is 3mm and the inner diameter is 2.5mm. The outer diameter of the inner ring 5 is 1.5mm and the inner diameter is 1mm. The width of the connecting beam 6 is 0.25mm.

[0018] The hemisphere 3 on the outer ring 4 of the upper ring 1 is a hollow hemisphere 7 with a diameter of 0.5 mm; the hemisphere 3 on the outer ring 4 of the lower ring 2 is a solid hemisphere 8 with a diameter of 0.4 mm.

[0019] In this embodiment, the sample to be tested is a magnetic metal material with the following composition: C-0.075, Si-0.25, Mn-1.2, Al-0.004, P-0.008, Ni-0.6, Cr-0.4, V-0.14, Nb-0.05, Cu-0.25, with the balance being Fe.

[0020] The metal was mechanically ground to a thickness of 40-60 μm and then cut into 3 mm diameter circular metal sheets using a punch for electrolytic double-jet experiments. The experimental parameters were set as follows: voltage: 35 V, photosensitivity: 15, temperature: -20 to -25 °C, and double-jet solution: 6% perchloric acid-alcohol solution. A 3 mm diameter circular magnetic metal material transmission sample was thus prepared.

[0021] Using the punched hole as the center, the above-mentioned 3mm transmission sample is protected by cutting the transmission thin area into small-sized transmission samples with a diameter of 1~2mm. Preferably, it is cut into small-sized circular or near-circular transmission samples with a diameter of 1.5mm.

[0022] The transmission sample stage used in this embodiment of the invention is a beryllium double tilt stage. First, use the provided stainless steel special tool, which is about 4cm long, to loosen the beryllium fixing ring counterclockwise and remove it. Then, rotate the sample rod 180° to make the inner thin ring fall off.

[0023] Place the lower ring of this invention on the central circular hole stage of the sample rod, and gently tap the sample rod so that the hemispheres at both ends of the clamping ring are precisely engaged in the corresponding grooves of the ring. Place the cut small-sized transmission sample face down at the center of the inner ring of the clamping ring, and then cover it with the upper ring, aligning the hollow hemisphere 7 on the upper ring with the solid hemisphere 8 on the lower ring to stably clamp the sample. Finally, place the beryllium fixing ring on top and use a special tool to rotate it clockwise to fix it in place. The clamping ring of this invention will replace the original thin ring and stably clamp small-sized transmission samples.

[0024] Following the method described in the above embodiment, a circular magnetic metal material transmission sample with a diameter of 3 mm was prepared by electrolytic double-jet printing of the sample to be tested with the same composition. It was then mounted and fixed using the existing thin ring and beryllium fixing ring.

[0025] The fixed samples from both the example and comparative examples were observed using a transmission electron microscope (TEM). The TEM used was a Tecnai F30 with an operating voltage of 300 kV. The observation results for both are shown below. Figure 4 and Figure 5 As shown.

[0026] Figure 5 (a) is a topographic image of the transmission sample in the comparative example. Its magnetism has a significant impact on the optical path system, causing image shift, severe astigmatism, and poor image quality. Figure 5 (b) is the selected area electron diffraction pattern of the transmission sample in the comparative example. By tilting the sample by angles α and β, the diffraction pattern of the

[100] zone axis of BCC was obtained. The results showed that when the angle α was tilted to ~±15° and the angle β was tilted to ~±10°, the sample image exhibited jitter and drift. The magnetic properties of the sample limited the tilt angle range, and it was impossible to obtain the low-index

[100] positive zone axis of BCC with good symmetry.

[0027] Figure 4 (a) is a topographic image of a small-sized transmission sample fixed using the clamping ring of this invention. The edges of the precipitated phase in the image are clear, astigmatism is reduced, and the image quality is significantly improved. Figure 4 (b) is the diffraction pattern of the

[100] zone axis of BCC obtained by tilting the zone axis of the sample. The diffraction pattern of the image is clear and has good symmetry. The tilt range of α angle is ~±25° and the tilt range of β angle is ~±20°.

[0028] TEM results show that the clamping ring provided by this invention can stably hold small-sized magnetic transmission samples. Compared with traditional sample testing methods, the image distortion rate is reduced, and the image quality and resolution are significantly improved. In selected area electron diffraction analysis, the tilt angle range is increased, and the sample applicability is improved by nearly 50%, solving the problem of limited tilt angle in transmission electron microscopy analysis of magnetic materials.

Claims

1. A sample clamping ring for transmission electron microscopy, characterized in that: It includes an upper ring (1), a lower ring (2) and a hemisphere (3). The upper ring (1) and the lower ring (2) are both double ring structures composed of an outer ring (4) and an inner ring (5). The outer ring (4) and the inner ring (5) are connected together by a connecting beam (6). The outer ring (4) of the upper ring (1) and the lower ring (2) are respectively provided with mutually cooperating hemispheres (3). The hemisphere (3) in the upper ring (1) or the hemisphere (3) in the lower ring (2) is a hollow structure.

2. The transmission electron microscope sample clamping ring according to claim 1, characterized in that: The diameter of the inner ring (5) in the upper ring (1) and lower ring (2) is matched to the size of the transmission electron microscope sample.

3. A transmission electron microscope sample clamping ring according to claim 2, characterized in that: The inner diameter of the inner ring (5) in the upper ring (1) and lower ring (2) is less than 1 mm.

4. A transmission electron microscope sample clamping ring according to claim 3, characterized in that: The thickness of both the upper ring (1) and the lower ring (2) is 0.05~0.1mm.

5. A transmission electron microscope sample clamping ring according to claim 1, characterized in that: The hemisphere (3) in the upper ring (1) is a hollow hemisphere, which is attached to the hemisphere (3) in the lower ring (2).

6. A method for testing samples using transmission electron microscopy, characterized in that: Includes the following steps: Step 1: Prepare a standard 3mm transmission sample from the magnetic material to be tested by electrolytic double-jet printing; Step 2: Cut the prepared transmission sample into small-sized samples with a diameter greater than 1 mm; Step 3: Place the small sample in the center of the inner ring (4) of the lower ring (2), and then place the upper ring (1) on the lower ring (2) so that the hemisphere (3) in the upper ring (1) and the hemisphere (3) in the lower ring (2) are fastened together; Step 4: Install the clamping ring with the sample loaded onto the transmission electron microscope sample rod and send it into the vacuum chamber of the transmission electron microscope for testing.

7. The method for testing samples using transmission electron microscopy according to claim 6, characterized in that: In step two, the prepared transmission sample is cut into a small circular or near-circular sample with a diameter greater than 1 mm centered on the hole.

8. A method for testing samples using transmission electron microscopy according to claim 6, characterized in that: In step two, the diameter of the small sample is 1~2mm.

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