In-situ XRD (X-Ray Diffraction) testing device

Abstract

The utility model discloses an in-situ XRD (X-Ray Diffraction) testing device, which relates to the field of in-situ characterization instruments and comprises a device main body, a heating mechanism, a vacuum joint, a heating joint and a second cooling joint, the device main body comprises a sample table and a window, a vacuum chamber is formed in the device main body, the sample table is arranged in the vacuum chamber, a sample groove corresponding to the window is formed in the sample table, and a second cooling channel is formed in the sample table; the heating mechanism is arranged in the vacuum chamber and is in contact with the sample table; the vacuum connector, the heating connector and the second cooling connector are all installed on the device body in a penetrating mode, the vacuum connector is communicated with the vacuum cavity, the heating connector is connected with the heating mechanism, and the second cooling connector is communicated with the second cooling channel. The utility model has the advantage that the switching of high-temperature / low-temperature environment fields is realized in the same device.

Description

TECHNICAL FIELD

[0001] The utility model relates to in situ characterization instrument field especially relates to a kind of in situ XRD testing device. BACKGROUND

[0002] X-ray diffraction (XRD) technology as the key technology of material science research field to the substance is crystal phase identification, judges crystallinity change, analyzes half-width etc. Important information, it is the important means of phase structure determination to the substance. As is known, the crystal phase of material will change greatly under high temperature / low temperature, in order to explore its crystal phase change process in real time, the most effective method is to carry out in situ experiment, therefore, in order to realize the real-time monitoring of reaction process under different temperature field, the phase structure parameter of reactant and product is determined, and it is very necessary to develop related X-ray diffractometer that can adapt to high-low temperature in situ XRD testing device. At present, researchers have successfully applied in situ high temperature XRD technology in experiment, for example, Huiling Zhao et al. Gradiently doped B atom with high binding energy into the near surface of NCM811 primary particles, and at the same time, Li2B4O7 with piezoelectric properties is coated on the outer surface of NCM811 secondary particles, the stress of high-nickel material in the cycle process makes Li2B4O7 further produce polarization electric field, and then regulates interface ion transport, in this research, the in situ XRD test results show that after the in situ construction of LBO, the change of lattice constant c axis of NCM811-LBO under high voltage is obviously inhibited.

[0003] In-situ XRD testing at high and low temperatures plays an important role in the study of materials science and engineering, especially in battery materials, catalysts, and phase change materials. With the growing demand for materials research, especially in the field of energy storage and conversion, there is increasing interest in the crystal structure changes of materials under actual working conditions. Many materials exhibit complex structural characteristics under different temperature conditions, including lattice expansion, phase transition, stress-strain behavior, etc., which directly affect the performance and application potential of materials. For example, in energy storage devices such as lithium-ion batteries, sodium-ion batteries, etc., electrode materials undergo multiple crystal structure changes during charging and discharging, and these changes are often significantly affected by temperature, which can accelerate the degradation of materials or cause irreversible structural damage under extreme temperature conditions. Therefore, in order to capture the structural evolution of materials under actual operating conditions through in-situ testing methods to better understand these changes, the demand for in-situ XRD testing devices with adjustable high and low temperatures has emerged. Traditional XRD testing devices are usually limited to room temperature conditions or have some heating functions, but the temperature range is relatively limited, and precise high and low temperature control cannot be achieved. For the study of materials behavior under extreme conditions, this limitation cannot meet the demand for accurate data in scientific research. High and low temperature in-situ XRD testing can also promote a deeper understanding of catalytic materials. In many catalytic reactions, temperature is an important factor affecting reaction activity and selectivity. By adjusting the temperature conditions, the crystal structure and active site changes of catalysts at different temperatures can be studied, especially the in-situ observation of phase transition, redox behavior, and surface lattice reorganization of catalysts. Catalysts often undergo irreversible structural changes during the reaction, and these changes are usually closely related to temperature. Through high and low temperature in-situ XRD testing, the structural characteristics of catalysts under high temperature reaction environments can be captured, thereby conducting in-depth research on their activity mechanisms, deactivation reasons, etc. In modern materials science, high and low temperature in-situ XRD testing can provide a powerful tool for exploring the performance boundaries of new materials. In particular, with the continuous emergence of emerging materials such as two-dimensional materials, nanostructured materials, etc., high and low temperature in-situ XRD testing can reveal the performance and failure mechanisms of these materials under extreme temperature conditions. High and low temperature in-situ XRD testing not only helps to reveal the structural stability of new materials in a wide temperature range, but also can be used to guide material design and process optimization. For example, in the design of materials for some extreme environment applications, high and low temperature in-situ XRD testing can obtain the crystal structure changes of materials in a wide temperature range, helping to select materials with better thermal stability. In the fields of electronics, aerospace, energy, etc., there are very high requirements for the temperature response characteristics of materials, and high and low temperature in-situ XRD testing can provide direct structural evolution data for the development of these key materials, thereby improving the reliability and durability of materials.

[0004] At present, a variety of separate in-situ high / low temperature XRD testing devices have been successfully developed and applied to material research systems. For example, the patent document with the publication number CN111007092A discloses a low temperature XRD testing device, testing equipment and testing system, which adopts an environmental cooling mode to make low temperature inert gas flow in an inner sealed cavity, so as to realize a low temperature environment in the inner sealed cavity. The patent document with the publication number CN110823934A discloses an in-situ measurement method for high temperature phase change of a sample surface micro-nano film layer, which realizes in-situ testing of high temperature phase change of the sample surface micro-nano film layer and can accurately obtain the phase change rule of the sample surface micro-nano film layer material. As described above, the existing in-situ XRD device can only meet the high temperature testing or low temperature testing environment requirement, and cannot realize switching of high / low temperature environment fields in the same device. In addition, the existing device has a complex structure and is difficult to operate in actual sample loading / taking. Practical new type content

[0005] The technical problem to be solved by the present utility model lies in how to realize switching of high / low temperature environment fields in the same device.

[0006] The present utility model realizes the above technical problem through the following technical means: an in-situ XRD testing device, comprising a device main body, a heating mechanism, a vacuum joint, a heating joint and a second cooling joint; the device main body comprises a sample table and a window, a vacuum cavity is formed in the inside of the device main body, the sample table is arranged in the vacuum cavity, a sample groove corresponding to the window is arranged on the sample table, and a second cooling channel is arranged in the inside of the sample table; the heating mechanism is arranged in the vacuum cavity and contacts the sample table; the vacuum joint, the heating joint and the second cooling joint are all installed through the device main body, the vacuum joint communicates with the vacuum cavity, the heating joint is connected with the heating mechanism, and the second cooling joint communicates with the second cooling channel.

[0007] As an optimized technical solution, the device main body further comprises a shell and an upper cover; the shell is a hollow structure, an opening is arranged at the top of the shell; the upper cover closes the top opening of the shell and is detachably fixedly connected with the shell, a test hole communicating with the inside of the shell is arranged at the middle position of the upper cover; and the window closes the test hole and is fixedly connected with the upper cover.

[0008] As an optimized technical solution, the in-situ XRD testing device further comprises a first cooling joint, a first cooling channel is arranged in the inside of the sidewall of the shell, and the first cooling joint is installed through the front side of the shell; and the first cooling joint communicates with the first cooling channel.

[0009] As an optimization technical scheme, the main body part of the window penetrates the test hole, and the lower edge of the window is detachably fixedly connected with the inner side of the upper cover.

[0010] As an optimization technical scheme, the main body part of the window is a hollow hemisphere.

[0011] As an optimization technical scheme, the device main body further comprises a side cover, the front side of the shell is provided with an opening, the side cover closes the front side opening of the shell and is detachably fixedly connected with the shell, and the second cooling connector penetrates the side cover.

[0012] As an optimization technical scheme, the device main body further comprises a boss, the two sides of the boss protrude from the inner and outer sides of the side cover respectively, the inner side of the boss contacts the sample table, and the second cooling connector penetrates the boss.

[0013] As an optimization technical scheme, the second cooling connector comprises a cooling pipe and a low-temperature nut, the cooling pipe penetrates the boss and enters the second cooling channel, and the part of the cooling pipe located on the outer side of the boss is fixedly connected with the boss through the low-temperature nut.

[0014] As an optimization technical scheme, the device main body further comprises a connecting plate, which is fixedly connected between the inner side wall of the shell and the sample table.

[0015] As an optimization technical scheme, the in-situ XRD testing device further comprises an adapter connector, which is installed on the bottom inner side of the shell, and the inner end of the heating connector is connected with the heating mechanism through the adapter connector.

[0016] The utility model discloses the advantages are in:

[0017] 1. The device realizes the switching of high-temperature / low-temperature environment field in the same device, realizes good refrigeration effect when testing in low temperature, ensures the rapid reduction of experimental temperature, can control temperature when testing in high temperature, eliminates the limitation that traditional device needs multiple independent systems to realize temperature control, realizes the efficient conversion of low-temperature mode and high-temperature mode, greatly simplifies experimental operation process, improves experimental efficiency, the vacuum connector can be connected with vacuum pump to realize vacuum test environment, eliminates the interference of impurity gas on experimental data, improves the accuracy of experimental results

[0018] 2. In the high-temperature test process, to avoid that heat is conducted to the shell when the sample table is heated and then potential safety hazard is caused, the shell can be connected with water cooling device or air cooling device to circulate cooling, ensures that the temperature of the shell is always in the safe range, fully considers the safety demand of laboratory operator, and reduces the safety hazard under the high-temperature test environment.

[0019] 3. Simple structure, small volume, suitable for different space experiment requirements, good space use flexibility, convenient sample loading, sampling and internal part maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 It is a top view schematic diagram of the in-situ XRD testing device.

[0021] Fig. 2 It is a front view schematic diagram of the in-situ XRD testing device.

[0022] Fig. 3 It is a sectional view schematic diagram of the in-situ XRD testing device. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0024] As shown in Figs. 1 to 3 The embodiments of the present application disclose an in-situ XRD testing device, which comprises a device main body 1, a heating mechanism 2, a vacuum joint 3, a heating joint 4, a first cooling joint 5, a second cooling joint 6 and a switching joint 7.

[0025] The device body 1 comprises a shell 11, an upper cover 12, a window 13, a side cover 14, a sample table 15, a boss 16 and a connecting plate 17; the shell 11 is a hollow rectangular structure with openings on the top and front side, and the inner wall of the shell 11 is provided with a first cooling channel; the upper cover 12 closes the top opening of the shell 11, and the four corners of the upper cover 12 are fixedly connected to the top of the shell 11 by screws; the middle position of the upper cover 12 is provided with a test hole communicating with the inside of the shell 11; the window 13 closes the test hole, and the main body part penetrates the test hole, and the lower edge is fixedly connected to the inner side of the upper cover 12 by a screw; the side cover 14 closes the front opening of the shell 11, and the four corners are fixedly connected to the front side of the shell 11 by screws; the inside of the shell 11, the upper cover 12, the window 13 and the side cover 14 forms a vacuum chamber, which serves as a high and low temperature environment generator, and plays a role in isolating air and protecting the uniformity of the test temperature; the sample table 15 is arranged in the vacuum chamber, and the top of the sample table 15 is provided with a sample groove corresponding to the window 13; the inside of the sample table 15 is provided with a second cooling channel; the boss 16 is an integral structure with the side cover 14, and the boss 16 protrudes from the inner and outer sides of the side cover 14, and the inner side of the boss 16 contacts the sample table 15; the connecting plate 17 is fixedly connected between the inner wall of the shell 11 and the sample table 15, and is used to fix the sample table 15 at a position corresponding to the window 13.

[0026] The shell 11, the upper cover 12, the side cover 14, the boss 16 and the connecting plate 17 need to have good rigidity, so their materials are made of various stainless steels or aluminum alloys, but not limited to them, which can be completed by mechanical processing.

[0027] In order to obtain a large-angle X-ray diffraction signal, the main body part of the window 13 is designed as a hollow hemisphere, so that the X-ray can always move along the normal direction of the hemisphere during the rotating movement of the X-ray machine, without causing additional influence on the XRD peak value of the sample; at the same time, in order to avoid the influence of X-ray incidence and emission signal on the test pattern peak signal and to realize good signal transmittance, the material of the window 13 is made of metal beryllium, graphite carbon and various high molecular plastics such as acrylic, PTFE (polytetrafluoroethylene) and PEEK (polyether ether ketone), etc., but not limited to them, to ensure the stability of X-ray incidence and emission signal, so that the measured data will not be affected or disturbed due to the material of the window, the accuracy of the test peak signal is improved, and the reliability of the experimental data is ensured.

[0028] The sample table 15 is a core component in the device, which adopts an integrated structure design, and the middle is hollowed out to form the second cooling channel; in order to conduct good heat conduction, the material of the sample table 15 needs to be selected as a metal with good thermal conductivity, which can include but is not limited to silver or copper; the sample table 15 is provided with a temperature measuring element, and the temperature regulation realizes accurate control in the range of-150-300℃, and the temperature control accuracy is ±1℃.

[0029] The heating mechanism 2 is arranged in the vacuum chamber and fixedly connected to the bottom of the sample table 15, and heats the sample table 15 by contacting the bottom of the sample table 15; the heating mechanism 2 adopts an electric heating mechanism, and the electric heating can realize accurate temperature control, and specifically can adopt heating resistance wire, platinum wire or tungsten wire and the like.

[0030] The vacuum joint 3, the heating joint 4 and the first cooling joint 5 are all installed through the front side of the shell 1, the second cooling joint 6 is installed through the boss 16, and the adapter joint 7 is installed on the inner side of the bottom of the shell 11; the vacuum joint 3 communicates with the vacuum chamber, and is used for connecting a vacuum pump outside to perform vacuumization on the vacuum chamber; the inner end of the heating joint 4 is connected to the heating mechanism 2 through a line connected through the adapter joint 7, and the outer end of the heating joint 4 is connected to a temperature controller outside the device main body 1 through a line; the first cooling joint 5 communicates with the first cooling channel, and the cooling medium of the first cooling channel is liquid nitrogen; the first cooling joint 5 can be connected to a pump outside to make the liquid nitrogen circulate and flow in the first cooling channel; the second cooling joint 6 adopts a quick coupling joint, and the second cooling joint 6 communicates with the second cooling channel; the cooling medium of the second cooling channel is water or air, and the second cooling joint 6 can be connected to a water cooling device or an air cooling device outside to make the water or air circulate and flow in the second cooling channel.

[0031] The second cooling joint 6 includes a cooling pipe 61 and a low-temperature nut 62, the cooling pipe 61 penetrates through the boss 16 and enters the second cooling channel, and the part of the cooling pipe 61 located outside the boss 16 is fixedly connected with the boss 16 through the low-temperature nut 62.

[0032] Working principle: first, use a hexagonal wrench to remove the screws at the four corners of the upper cover 12, separate the upper cover 12 together with the window 13 from the shell 11, and place the sample in the sample groove on the top of the sample table 15; then use the screws to fixedly connect the upper cover 12 with the shell 11, and use the vacuum pump to perform vacuumization on the vacuum chamber; then use the X-ray light machine to perform XRD test on the sample; during the test, the control system controls the pump to circulate the liquid nitrogen or controls the temperature controller to work, and cools or heats the sample table 15, so that the XRD characterization of the sample under different temperature environments can be performed; at the same time, the water cooling device or the air cooling device is used to make the water or air circulate and flow in the second cooling channel, so as to ensure the uniformity of the temperature of the outer surface of the device main body 1 under high temperature and low temperature environments.

[0033] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An in-situ XRD testing apparatus, characterized by: The device body comprises a sample table and a window, the inside of the device body forms a vacuum chamber, a sample table is arranged in the vacuum chamber, a sample groove corresponding to the window is arranged on the sample table, and a second cooling channel is arranged in the inside of the sample table.

2. The in-situ XRD testing device of claim 1, wherein: The device body further comprises a shell and an upper cover; the shell is a hollow structure, and the top of the shell is provided with an opening; the upper cover closes the top opening of the shell and is detachably fixedly connected with the shell, and a test hole communicating with the inside of the shell is arranged at the middle position of the upper cover; and the window closes the test hole and is fixedly connected with the upper cover.

3. The in-situ XRD testing device of claim 2, wherein: The in-situ XRD testing device further comprises a first cooling connector, a first cooling channel is arranged in the inside of the sidewall of the shell, and the first cooling connector is installed through the front side of the shell; and the first cooling connector communicates with the first cooling channel.

4. The in-situ XRD testing apparatus of claim 2, wherein: The main body part of the window penetrates the test hole, and the lower edge of the window is detachably fixedly connected with the inside of the upper cover.

5. The in-situ XRD testing device of claim 4, wherein: The main body part of the window is a hollow hemisphere.

6. The in-situ XRD testing apparatus of claim 2, wherein: The device body further comprises a side cover, the front side of the shell is provided with an opening, the side cover closes the front side opening of the shell and is detachably fixedly connected with the shell, and the second cooling connector penetrates the side cover.

7. The in-situ XRD testing apparatus of claim 6, wherein: The device body further comprises a boss, the two sides of the boss protrude from the inside and outside of the side cover respectively, the inside of the boss contacts the sample table, and the second cooling connector is installed through the boss.

8. The in-situ XRD testing apparatus of claim 7, wherein: The second cooling connector comprises a cooling pipe and a low-temperature nut, the cooling pipe penetrates the boss and enters the second cooling channel, and the part of the cooling pipe located outside the boss is fixedly connected with the boss through the low-temperature nut.

9. The in-situ XRD testing apparatus of claim 2, wherein: The device body further comprises a connecting plate, which is fixedly connected between the inside sidewall of the shell and the sample table.

10. The in-situ XRD testing apparatus of claim 2, wherein: The in-situ XRD testing device further comprises an adapter connector, which is installed at the bottom inside of the shell, and the inner end of the heating connector is connected with the heating mechanism through the adapter connector.

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