A cryogenic sample rod for a transmission electron microscope

Abstract

The utility model discloses a low temperature sample pole for transmission electron microscope, including the outer jar, the left -hand end fixedly connected with the heat insulation shell of outer jar, the low temperature pole core is arranged in the heat insulation shell, the left -hand end fixedly connected with sample stage of low temperature pole core, the sample stage sets up in the left side of heat insulation shell, the left side of heat insulation shell is fixedly connected with the protection seat, the protection seat sets up in the below of sample stage, and low temperature pole core penetrates the sleeve and the through -hole, and under the action of first elastic sheet and second elastic sheet, the vibration of low temperature pole core from the cold source is alleviated, thereby alleviating the vibration to sample, through the outside dry inert gas source to the aeration of microcavity, slowly fills in dry inert gas in microcavity, makes its pressure slightly higher than the vacuum pressure of electron microscope lens barrel, and the gas evenly slowly leaks out through first gap and second gap, forms an even air curtain around the sample, and the sample is protected, thereby actively prevents the ice pollution.

Description

Technical Field

[0001] This utility model relates to the field of transmission electron microscopy (TEM) technology, specifically to a low-temperature sample holder for TEM. Background Technology

[0002] Transmission electron microscopy (TEM) is an important experimental tool in the fields of life sciences and materials science. Its precision far surpasses that of optical microscopes, and the high-energy electron beam can penetrate samples, enabling characterization of their internal microstructure. When characterizing the internal microstructure of samples using TEM, a sample holder is often inserted into the microscope. The sample holder is rotated by the goniometer stage within the microscope to allow for multi-angle observation of the sample. The sample holder is one of the most important components of the TEM, serving to support the sample. In cryogenic applications, the cryogenic sample holder can be cooled to the required low temperature (e.g., 170°C) using cryogenic liquids such as liquid nitrogen. This reduces potential carbon contamination and damage to the sample under electron beam irradiation and allows for in-situ studies in the cryogenic range of 170°C to +100°C. However, cryogenic liquids often vaporize during the cooling process, causing vibrations that can affect the sample holder and measurement results. When the pre-cooled sample holder is inserted into the microscope tube from the transfer chamber, its shaft and sample holder are exposed to the residual gas environment of the tube. These gases (especially water vapor) will quickly condense into ice crystals when they encounter the ultra-low temperature rod, depositing near the sample, severely obstructing the observation field of view and contaminating the sample. Utility Model Content

[0003] The purpose of this section is to outline some aspects of the embodiments of this utility model and to briefly introduce some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be used to limit the scope of this utility model.

[0004] In view of the problems existing in the above and / or existing cryogenic sample holders for transmission electron microscopy, this utility model is proposed.

[0005] Therefore, the purpose of this invention is to provide a cryogenic sample holder for transmission electron microscopy. The cryogenic rod core passes through a sleeve and a through hole. Under the action of the first and second elastic sheets, the vibration of the cryogenic rod core from the cold source is reduced, thereby reducing the vibration on the sample. A dry inert gas source is used to circulate gas into the microcavity. The microcavity is slowly filled with dry inert gas, and its pressure is slightly higher than the vacuum pressure of the electron microscope tube. The gas leaks out evenly and slowly through the first and second slits, forming a uniform gas curtain around the sample to protect it. This positive pressure airflow can effectively prevent residual gas (especially water vapor) in the electron microscope vacuum from entering the microcavity and condensing on the surface of the cryogenic sample, thereby actively preventing ice contamination.

[0006] To solve the above-mentioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: A low-temperature sample holder for transmission electron microscopy includes an outer canister, an insulating outer shell fixedly connected to the left end of the outer canister, a low-temperature rod core extending through the inner side of the insulating outer shell, a sample stage fixedly connected to the left end of the low-temperature rod core, the sample stage being disposed on the left side of the insulating outer shell, a protective seat fixedly connected to the left side of the insulating outer shell, and the protective seat being disposed below the sample stage.

[0007] The heat insulation shell includes a ring frame fixedly installed on the inner wall of the heat insulation shell, a sleeve is provided between the ring frames, a first elastic sheet is fixedly connected to the outer ring of the sleeve, a limit post is fixedly connected to the inside of the heat insulation shell near the left side, a circular groove is opened inside the limit post, and a second elastic sheet is provided inside the circular groove.

[0008] The protective seat includes an arc-shaped connecting pipe fixedly connected to the side of the protective seat. A first slit is provided on the inner side of the arc-shaped connecting pipe. A micro cavity is provided inside the protective seat. The micro cavity is connected to the arc-shaped connecting pipe. A second slit is provided on the side of the protective seat. The second slit is connected to the micro cavity. The micro cavity is connected to an external dry inert gas source interface through a connecting pipe.

[0009] In a preferred embodiment of the low-temperature sample holder for transmission electron microscopy described in this utility model, the inner container is fixedly connected to the inner container via a connecting rod, and a vacuum cavity is provided between the inner container and the outer container.

[0010] As a preferred embodiment of the low-temperature sample holder for transmission electron microscopy described in this utility model, a vacuum extraction valve tube is fixedly and penetrates the right side of the outer canister, a connecting plate is fixedly and penetrates the outer ring of the vacuum extraction valve tube, a screw is inserted through the connecting plate, and the left end of the screw is threadedly connected to the outer canister.

[0011] As a preferred embodiment of the low-temperature sample holder for transmission electron microscopy described in this utility model, a refrigerant filling valve tube is fixedly connected to the outer side of the inner canister, and the end of the refrigerant filling valve tube away from the inner canister is fixedly inserted through the outer canister.

[0012] As a preferred embodiment of the low-temperature sample rod for transmission electron microscopy described in this utility model, a protective tube is fixedly connected to the outer ring of the outer can, the protective tube is disposed around the refrigerant filling valve tube, a protective sleeve is threaded onto the external part of the protective tube, and a pressure relief valve is provided at the top of the protective sleeve.

[0013] As a preferred embodiment of the low-temperature sample rod for transmission electron microscopy described in this utility model, the heat insulation shell further includes a support column fixedly connected to the right side of the limiting column. Both the support column and the limiting column have through holes inside. The center point of the through hole and the center point of the circular groove are on the same straight line. The left end of the low-temperature rod core passes through the sleeve and the through holes in the limiting column and the support column.

[0014] As a preferred embodiment of the low-temperature sample holder for transmission electron microscopy described in this utility model, the outer ring of the support column has an annular array of opening slots.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: the low-temperature rod core penetrates the sleeve and through hole, and the vibration of the low-temperature rod core from the cold source is reduced under the action of the first elastic sheet and the second elastic sheet, thereby reducing the vibration on the sample. The micro-cavity is vented through an external dry inert gas source, and the micro-cavity is slowly filled with dry inert gas, so that its pressure is slightly higher than the vacuum pressure of the electron microscope tube. The gas leaks out evenly and slowly through the first slit and the second slit, forming a uniform gas curtain around the sample to protect the sample. This positive pressure airflow can effectively prevent residual gas (especially water vapor) in the electron microscope vacuum from entering the micro-cavity and condensing on the surface of the low-temperature sample, thereby actively preventing ice contamination. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them: Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of the outer tank, inner tank, and heat-insulating shell of this utility model; Figure 3This is a schematic diagram of the refrigerant filling valve tube, protective tube, and protective sleeve of this utility model. Figure 4 This is a schematic diagram of the sleeve and the first elastic sheet of this utility model; Figure 5 This is a schematic diagram of the cross-sectional structure of the limiting column and the supporting column of this utility model; Figure 6 This is a schematic diagram of the protective base, arc-shaped connecting pipe, first gap, and second gap of this utility model.

[0017] In the diagram: 1. Outer tank; 2. Connecting rod; 3. Inner tank; 4. Vacuum chamber; 5. Vacuum extraction valve pipe; 6. Connecting disc; 7. Screw; 8. Refrigerant filling valve pipe; 9. Protective pipe; 10. Protective sleeve; 11. Thermal insulation shell; 1101. Ring baffle; 1102. Sleeve; 1103. First elastic sheet; 1104. Limiting post; 1105. Support post; 1106. Opening groove; 1107. Through hole; 1108. Round hole groove; 1109. Second elastic sheet; 12. Low temperature rod core; 13. Sample stage; 14. Protective seat; 1401. Arc-shaped connecting pipe; 1402. First gap; 1403. Second gap. Detailed Implementation

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0019] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views showing the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0021] This invention provides a cryogenic sample holder for a transmission electron microscope (TEM). The cryogenic rod core passes through a sleeve and a through hole. Under the action of a first elastic sheet and a second elastic sheet, the vibration of the cryogenic rod core from the cold source is reduced, thereby reducing the vibration on the sample. A dry inert gas source is used to circulate gas into the microcavity. The microcavity is slowly filled with dry inert gas, and its pressure is slightly higher than the vacuum pressure of the TEM tube. The gas leaks out evenly and slowly through the first and second slits, forming a uniform gas curtain around the sample to protect it. This positive pressure airflow can effectively prevent residual gas (especially water vapor) in the TEM vacuum from entering the microcavity and condensing on the surface of the cryogenic sample, thereby actively preventing ice contamination.

[0022] Figures 1-6 The diagram shown is a schematic representation of an embodiment of a cryogenic sample holder for a transmission electron microscope according to this invention. Please refer to [link / reference]. Figures 1-6 A cryogenic sample rod for transmission electron microscopy according to this embodiment includes an outer canister 1. A thermal insulation shell 11 is fixedly connected to the left end of the outer canister 1. A cryogenic rod core 12 is disposed inside the thermal insulation shell 11. A sample stage 13 is fixedly connected to the left end of the cryogenic rod core 12. The sample stage 13 is disposed on the left side of the thermal insulation shell 11. A protective seat 14 is fixedly connected to the left side of the thermal insulation shell 11. The protective seat 14 is disposed below the sample stage 13.

[0023] The thermal insulation shell 11 includes a ring retainer 1101 fixedly mounted on the inner wall of the thermal insulation shell 11. A sleeve 1102 is provided between the ring retainers 1101. A first elastic sheet 1103 is fixedly connected to the outer ring of the sleeve 1102. A limiting post 1104 is fixedly connected to the inside of the thermal insulation shell 11 near the left side. A circular groove 1108 is formed inside the limiting post 1104. A second elastic sheet 1109 is provided inside the circular groove 1108. The thermal insulation shell 11 also includes... The support column 1105 is fixedly connected to the right side of the limiting post 1104. Both the support column 1105 and the limiting post 1104 have through holes 1107. The center point of the through hole 1107 and the center point of the circular groove 1108 are on the same straight line. The left end of the low temperature rod core 12 passes through the sleeve 1102 and the through holes 1107 in the limiting post 1104 and the support column 1105 in sequence. The outer ring of the support column 1105 has opening grooves 1106 in a ring array.

[0024] The cryogenic rod core 12 is fixedly connected to the second elastic sheet 1109. The second elastic sheet 1109 is in contact with the inner wall of the circular groove 1108. The circular groove 1108 limits the movement of the second elastic sheet 1109. The inner diameter of the circular groove 1108 is larger than the inner diameter of the through hole 1107. The second elastic sheets 1109 are arranged in a ring array on the cryogenic rod core 12. The open groove 1106 reduces the contact between the support column 1105 and the heat insulation shell 11, reducing the heat conduction area. The core 12 can just pass through the through hole 1107. The first elastic sheet 1103 is in contact with the inner wall of the heat insulation shell 11 to reduce the impact of vibration on the low temperature core 12. At the same time, it reduces the direct contact between the sleeve 1102 and the heat insulation shell 11, reducing the heat conduction area. The first elastic sheet 1103 is arranged in multiple sets in a ring array about the sleeve 1102. The low temperature core 12 can just pass through the hole opened in the sleeve 1102. The right end of the low temperature core 12 penetrates into the inner tank 3 and contacts the cold source.

[0025] The protective seat 14 includes an arc-shaped connecting pipe 1401 fixedly connected to the side of the protective seat 14. A first slit 1402 is provided on the inner side of the arc-shaped connecting pipe 1401. A micro cavity is provided inside the protective seat 14. The micro cavity is connected to the arc-shaped connecting pipe 1401. A second slit 1403 is provided on the side of the protective seat 14. The second slit 1403 is connected to the micro cavity. The micro cavity is connected to an external dry inert gas source interface through a connecting pipe.

[0026] An external dry inert gas source is used to supply gas into the microcavity. The microcavity is slowly filled with dry inert gas, and its pressure is slightly higher than the vacuum pressure of the electron microscope tube. The gas leaks out evenly and slowly through the first slit 1402 and the second slit 1403, forming a uniform gas curtain around the sample to protect it. The microcavity is not directly connected to the gas source. A miniature high-precision pressure regulator and a mass flow controller are also installed on the connecting pipeline to reduce the pressure input from the gas source to a stable level, which is slightly higher than the vacuum pressure of the electron microscope.

[0027] An inner tank 3 is fixedly connected to the inner wall of the outer tank 1 via a connecting rod 2. A vacuum chamber 4 is provided between the inner tank 3 and the outer tank 1. A vacuum extraction valve pipe 5 is fixedly installed through the right side of the outer tank 1. A connecting plate 6 is fixedly installed through the outer ring of the vacuum extraction valve pipe 5. A screw 7 is installed through the connecting plate 6. The left end of the screw 7 is threadedly connected to the outer tank 1. A refrigerant filling valve pipe 8 is fixedly connected to the outer side of the inner tank 3. The end of the refrigerant filling valve pipe 8 away from the inner tank 3 is fixedly installed through the outer tank 1. A protective pipe 9 is fixedly connected to the outer ring of the outer tank 1. The protective pipe 9 is located around the refrigerant filling valve pipe 8. A protective sleeve 10 is threadedly connected to the outer side of the protective pipe 9. A pressure relief valve is provided at the top of the protective sleeve 10.

[0028] The connection between the outer tank 1 and the refrigerant filling valve pipe 8 is sealed, and a sealing element is provided between the outer tank 1 and the connecting plate body 6. A pressure relief port is provided on the refrigerant filling valve pipe 8. The pressure relief port is used to release pressure when the internal pressure of the inner tank 3 is abnormal. The space between the protective sleeve 10 and the protective pipe 9 is used to buffer and prevent sudden pressure release from affecting the staff and testing equipment. When the pressure between the protective sleeve 10 and the protective pipe 9 reaches a certain value, the pressure relief valve at the top of the protective sleeve 10 is used to further release pressure.

[0029] Combination Figures 1-6The specific usage process of a low-temperature sample rod for transmission electron microscopy in this embodiment is as follows: The sample is placed on the sample stage 13 and examined by the electron microscope. A dry inert gas source is introduced into the microcavity, and the microcavity is slowly filled with dry inert gas, making its pressure slightly higher than the vacuum pressure of the electron microscope tube. The gas leaks out evenly and slowly through the first slit 1402 and the second slit 1403, forming a uniform gas curtain around the sample to protect it. The low-temperature rod core 12 passes through the sleeve 1102 and the through hole 1107. Under the action of the first elastic sheet 1103 and the second elastic sheet 1109, the vibration of the low-temperature rod core 12 from the cold source is reduced, thereby reducing the vibration on the sample.

[0030] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cryogenic sample holder for transmission electron microscopy, comprising an outer canister (1), characterized in that: The outer can (1) is fixedly connected to a heat-insulating shell (11) at the left end. A low-temperature rod core (12) is installed through the inside of the heat-insulating shell (11). A sample stage (13) is fixedly connected to the left end of the low-temperature rod core (12). The sample stage (13) is located on the left side of the heat-insulating shell (11). A protective seat (14) is fixedly connected to the left side of the heat-insulating shell (11). The protective seat (14) is located below the sample stage (13). The heat insulation shell (11) includes a ring baffle (1101) fixedly disposed on the inner wall of the heat insulation shell (11), a sleeve (1102) is disposed between the ring baffles (1101), a first elastic sheet (1103) is fixedly connected to the outer ring of the sleeve (1102), a limiting post (1104) is fixedly connected to the inside of the heat insulation shell (11) near the left side, a circular hole groove (1108) is opened in the inside of the limiting post (1104), and a second elastic sheet (1109) is disposed in the inside of the circular hole groove (1108). The protective seat (14) includes an arc-shaped connecting pipe (1401) fixedly connected to the side of the protective seat (14). The inner side of the arc-shaped connecting pipe (1401) is provided with a first slit (1402). The protective seat (14) is provided with a micro cavity inside. The micro cavity is connected to the arc-shaped connecting pipe (1401). The side of the protective seat (14) is provided with a second slit (1403). The second slit (1403) is connected to the micro cavity. The micro cavity is connected to an external dry inert gas source interface through a connecting pipe.

2. The low-temperature sample holder for transmission electron microscopy according to claim 1, characterized in that: The inner wall of the outer tank (1) is fixedly connected to the inner tank (3) by the connecting rod (2), and a vacuum cavity (4) is provided between the inner tank (3) and the outer tank (1).

3. A low-temperature sample holder for transmission electron microscopy according to claim 1, characterized in that: A vacuum extraction valve pipe (5) is fixedly installed through the right side of the outer tank (1). A connecting disc (6) is fixedly installed through the outer ring of the vacuum extraction valve pipe (5). A screw (7) is installed through the connecting disc (6). The left end of the screw (7) is threadedly connected to the outer tank (1).

4. A low-temperature sample holder for transmission electron microscopy according to claim 2, characterized in that: The outer side of the inner tank (3) is fixedly connected to a refrigerant filling valve pipe (8), and the end of the refrigerant filling valve pipe (8) away from the inner tank (3) is fixedly inserted through the outer tank (1).

5. A low-temperature sample holder for transmission electron microscopy according to claim 1, characterized in that: The outer ring of the outer tank (1) is fixedly connected to a protective tube (9), which is located around the refrigerant filling valve tube (8). The protective tube (9) is connected to a protective sleeve (10) by external thread, and a pressure relief valve is provided at the top of the protective sleeve (10).

6. A low-temperature sample holder for transmission electron microscopy according to claim 1, characterized in that: The thermal insulation shell (11) also includes a support column (1105) fixedly connected to the right side of the limiting column (1104). Both the support column (1105) and the limiting column (1104) have through holes (1107) inside. The center point of the through hole (1107) and the center point of the circular groove (1108) are on the same straight line. The left end of the low temperature rod core (12) passes through the sleeve (1102) and the through hole (1107) inside the limiting column (1104) and the support column (1105).

7. A low-temperature sample holder for transmission electron microscopy according to claim 6, characterized in that: The outer ring of the support column (1105) has an opening groove (1106) in a ring array.

Images