Lunar soil material characterization method based on vacuum interconnection
By conducting multi-technical characterization analysis in a vacuum environment, the problem of easy contamination and change in intrinsic properties during the analysis process is solved, and a comprehensive elemental analysis without damage is achieved, ensuring the accuracy and effectiveness of the detection results.
Patent Information
- Application Number
- CN202311797721.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2025-06-27
Smart Images
Figure CN120213994A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of material analysis, and specifically relates to a method for characterizing lunar soil materials based on vacuum interconnection. Background Art
[0002] Lunar soil is the soil on the lunar surface, an important material in the lunar exploration project, and a precious resource in the history of human spaceflight. To comprehensively and deeply understand lunar soil materials, it is generally necessary to jointly use a variety of test and analysis methods. In the field of geological science, when studying mineral rock and soil samples, the samples are usually dissolved, and then ICP-MS and other methods are used to obtain the results of the elemental content distribution in the samples. This method can obtain accurate information on the elemental content in the samples, but the damage to the samples by this technology is irreversible. In recent years, technologies such as visible-near-infrared imaging spectrometers have been developed to achieve non-destructive characterization of lunar samples, but this method cannot obtain material physical and chemical information such as the elemental and isotope composition, chemical valence state, and microscopic morphology characteristics of the samples, and other test methods still need to be combined.
[0003] Lunar soil samples are a very heterogeneous mixture system, and the testing process will lead to incorrect analysis and ineffective correlation of data. More importantly, the vacuum degree on the lunar surface is generally between 10 -10 ~10 -12 Pa. In such an environment, even metal elements with very active chemical properties can maintain their metallic state. However, in the atmospheric environment, due to the presence of water and oxygen, many metal elements in low valence states cannot maintain their low valence states and exist stably. Therefore, lunar soil samples are likely to be contaminated by the atmosphere and change their intrinsic properties when exposed to the atmosphere. Summary of the Invention
[0004] The purpose of this application is to provide a method for characterizing lunar soil materials based on vacuum interconnection to solve the problems that the elemental analysis method of materials in the prior art may cause lunar soil samples to be contaminated and change their intrinsic properties when analyzing lunar soil samples, and the testing process will lead to incorrect analysis and ineffective correlation of data.
[0005] To achieve the above purpose, a technical solution adopted by this application is:
[0006] Provide a method for characterizing lunar soil materials based on vacuum interconnection, including:
[0007] Embed and fix the lunar soil sample on the sample carrier in the glove box;
[0008] Transfer the sample carrier to the chamber of the scanning electron microscope through an ultra-high vacuum pipeline, perform EDS energy spectrum analysis on the lunar soil sample, and screen to obtain the target detection area;
[0009] Transfer the sample carrier to the chamber of the X-ray photoelectron spectrometer through an ultra-high vacuum pipeline, and perform elemental analysis on the target detection area;
[0010] Transfer the sample carrier to the chamber of the focused ion beam equipment through an ultra-high vacuum pipeline, and perform ion beam slicing on the target detection area to obtain a focused ion beam slice;
[0011] Transfer the focused ion beam slice to the chamber of the time-of-flight secondary ion mass spectrometer through an ultra-high vacuum pipeline, and analyze the elements and their related isotope contents on the cross-section of the focused ion beam slice.
[0012] In one or more embodiments, the step of embedding and fixing the lunar soil sample on the sample carrier in the glove box is: embedding and fixing the lunar soil sample on the sample carrier using indium material.
[0013] In one or more embodiments, the sample carrier is a silicon wafer.
[0014] In one or more embodiments, the step of performing EDS energy spectrum analysis on the lunar soil sample and screening to obtain the target detection area is specifically: based on the results of the EDS energy spectrum analysis, screen the area with the most abundant target elements as the target detection area.
[0015] In one or more embodiments, the target element is the Fe element.
[0016] In one or more embodiments, the step of transferring the sample carrier to the chamber of the X-ray photoelectron spectrometer through an ultra-high vacuum pipeline and performing elemental analysis on the selected target detection area is specifically:
[0017] Perform XPS analysis on the target detection area to obtain the elements and their valence state information on the surface of the target detection area.
[0018] In one or more embodiments, the step of transferring the sample carrier to the chamber of the X-ray photoelectron spectrometer through an ultra-high vacuum pipeline and performing elemental analysis on the selected target detection area further includes:
[0019] Perform etching on the target detection area at multiple different depths. After each etching is completed, perform XPS analysis on the surface exposed inside the target detection area to obtain the valence state change information of the target element at different depths in the target detection area.
[0020] In one or more embodiments, in the step of performing etching on the target detection area at multiple different depths, the etching is specifically Ar ion etching.
[0021] In one or more embodiments, the thickness of the focused ion beam slice is 90 - 110 nm.
[0022] Before the step of transferring the focused ion beam slice to the device cavity of the time-of-flight secondary ion mass spectrometer using an ultra-high vacuum pipeline in one or more embodiments, the following steps are further included:
[0023] In the focused ion beam device cavity, an internal scanning electron microscope is used to image the cross-section of the focused ion beam slice.
[0024] Different from the prior art, the beneficial effects of this application are:
[0025] The lunar soil material characterization method of this application can realize multi-technique combined characterization and analysis at the same area of the same sample. The characterization results obtained by each technique can be effectively correlated with each other to ensure the accuracy of the detection results;
[0026] During the entire detection process of the lunar soil material characterization method of this application, the lunar soil sample is in an ultra-high vacuum environment and is not affected by the atmospheric environment, which can avoid changes in the intrinsic properties of the lunar soil sample and ensure the effectiveness of the detection results;
[0027] During the entire detection process of the lunar soil material characterization method of this application, the loss of the sample is extremely small, avoiding damage to precious lunar soil samples. Description of the Drawings
[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0029] Figure 1 It is a schematic flowchart of an embodiment of the lunar soil material characterization method based on vacuum interconnection of this application;
[0030] Figure 2 It is a photographed image of the embedded lunar soil sample in an embodiment of this application;
[0031] Figure 3 It is an SEM image of the lunar soil sample in an embodiment of this application;
[0032] Figure 4 It is an XPS spectrum of the lunar soil sample in an embodiment of this application;
[0033] Figure 5 It is an SEM image of the cross-section of the focused ion beam slice of the lunar soil sample in an embodiment of this application;
[0034] Figure 6 It is a TOF-SIMS analysis diagram of the cross-section of a focused ion beam slice of a lunar soil sample in an embodiment of the present application. Detailed implementation manners
[0035] In order to enable those skilled in the art to better understand the technical solutions in the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
[0036] On December 17, 2020, the sample cabin of Chang'e-5 successfully landed in Siziwang Banner, Inner Mongolia, bringing back 1,731 grams of lunar samples. In November 2021, the Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences retrieved the second batch of Chang'e-5 rock fragments CE5C0000YJYX104 (4.8 mg) samples from Beijing to Suzhou.
[0037] Lunar soil is the soil on the lunar surface, an important material in the lunar exploration project, and also a precious resource in the history of human spaceflight. To comprehensively and deeply understand lunar soil materials, it is generally necessary to jointly use a variety of test and analysis means.
[0038] Currently, the conventional sample detection scheme in the field of geological science requires dissolving the sample and then using means such as ICP-MS to obtain the results of the elemental content distribution in the sample. This method can obtain accurate information on the elemental content in the sample, but the damage to the sample by this technology is irreversible. Since lunar soil samples are extremely precious, obviously the conventional dissolution detection method is not applicable.
[0039] Technologies such as visible-near-infrared imaging spectrometers developed in recent years can achieve non-destructive characterization of lunar samples, but this method cannot obtain material physical and chemical information such as the elemental and isotope composition, chemical valence state, and microscopic morphology characteristics of the sample, and other test means still need to be combined.
[0040] More importantly, the sample is a very heterogeneous mixture system. Currently, conventional detection methods may face problems such as multiple sample preparations, exposure to the atmosphere, testing different samples or different positions of the same sample, resulting in incorrect analysis and ineffective correlation of data. In particular, due to the differences between the lunar surface environment and the Earth's atmospheric environment, any exposure of lunar soil samples in the environment may cause changes in their intrinsic properties.
[0041] To solve the above problems and achieve non-destructive and comprehensive analysis of lunar soil samples, the applicant has developed a method for characterizing lunar soil materials based on vacuum interconnection. This method can perform non-destructive and comprehensive elemental analysis on lunar soil samples and avoid contamination of the lunar soil samples, which may affect their intrinsic properties.
[0042] Specifically, please refer to Figure 1 , Figure 1 which is a schematic flow chart of an embodiment of the method for characterizing lunar soil materials based on vacuum interconnection in this application.
[0043] As shown in Figure 1 , the method for characterizing lunar soil materials includes:
[0044] S100. Embed and fix the lunar soil sample on the sample carrier in a glove box.
[0045] First, in order to ensure the consistency of the selected area of the sample for subsequent detection, it is necessary to embed and fix the lunar soil sample.
[0046] In one embodiment, the glove box can be an inert gas glove box to fully protect the lunar soil sample.
[0047] In one embodiment, the lunar soil sample can be fixed by embedding with indium material. Among them, the sample carrier can be a silicon wafer.
[0048] Please refer to Figure 2 , Figure 2 which is a photographed image of the embedded lunar soil sample in an embodiment of this application. As shown in Figure 2 , the lunar soil sample is embedded and fixed on a 2-inch silicon wafer with indium material.
[0049] S200. Transfer the sample carrier to the chamber of the scanning electron microscope through an ultra-high vacuum pipeline, perform EDS energy spectrum analysis on the lunar soil sample, and screen the target detection area.
[0050] After the sample embedding is completed, the sample carrier can be directly transferred to the SEM equipment chamber in a vacuum environment by using the ultra-high vacuum pipeline of the vacuum interconnection system.
[0051] In one embodiment, the inside of the ultra-high vacuum pipeline can be an ultra-high vacuum environment of 10 -10 mbar to simulate the lunar surface environment and avoid changes in the intrinsic properties of the lunar soil sample.
[0052] Using the SEM equipment, EDS energy spectrum analysis can be performed on the lunar soil sample to achieve qualitative analysis of the elemental distribution of the lunar soil sample, so that the target detection area can be screened from the lunar soil sample.
[0053] Specifically, the target detection region can be the region where the content of specific target elements is the richest, which helps in the specific analysis of multiple dimensions such as the specific distribution and valence state of the target elements.
[0054] In one embodiment, the target element can be the Fe element.
[0055] Please refer to Figure 3 , Figure 3 which is the SEM image of the lunar soil sample in an embodiment of the present application. Based on the EDS energy spectrum of the lunar soil sample that can be obtained during the scanning analysis by the SEM device, the region with rich content of target elements is selected as the target detection region.
[0056] S300. Use the ultra-high vacuum pipeline to transfer the sample carrier to the equipment cavity of the X-ray photoelectron spectrometer to perform elemental analysis on the target detection region.
[0057] After selecting the target detection region, the sample carrier can be directly transferred to the equipment cavity of the X-ray photoelectron spectrometer (XPS) in a vacuum environment by using the ultra-high vacuum pipeline of the vacuum interconnection system, and XPS analysis is performed on the target detection region of the lunar soil sample, so as to obtain the elements and their valence state information of the detection region.
[0058] In one embodiment, the method for performing elemental analysis on the target detection region can be:
[0059] First, XPS analysis can be performed on the target detection region, so as to obtain the elements and their valence state information on the surface of the target detection region.
[0060] After that, etching technology can be used to perform etching on the target detection region at multiple different depths, and XPS is performed on the surfaces at different depths exposed after each etching, so as to obtain the valence state change information of the target element at different depths in the target detection region.
[0061] Please refer to Figure 4 , Figure 4 which is the XPS spectrum of the lunar soil sample in an embodiment of the present application. Based on the cooperation of XPS analysis and etching technology, the element content on the surface of the target detection region and the valence state information of each element, as well as the valence state change information of the target element at different depths inside the target detection region can be obtained.
[0062] S400. Use the ultra-high vacuum pipeline to transfer the sample carrier to the equipment cavity of the focused ion beam to perform ion beam slicing on the target detection region to obtain a focused ion beam slice.
[0063] After XPS analysis, the sample carrier can be directly transferred to the equipment cavity of the focused ion beam (FIP) in a vacuum environment by using the ultra-high vacuum pipeline of the vacuum interconnection system.
[0064] Ion beam slicing of the target detection area can be performed through the focused ion beam equipment chamber to obtain a focused ion beam slice, which helps subsequent elemental analysis of the cross-section.
[0065] In one embodiment, the thickness of the focused ion beam slice can be only 90 - 110 nm. Due to the ultra-high vacuum state in the vacuum interconnection system, the cross-section exposed by the focused ion beam slice can also be well protected, and its chemical properties will not be affected by the external environment.
[0066] In one embodiment, the cross-section of the focused ion beam slice can also be imaged using the built-in scanning electron microscope in the focused ion beam equipment chamber, which helps subsequent elemental analysis of the cross-section.
[0067] Please refer to Figure 5 , Figure 5 which is the SEM image of the cross-section of the focused ion beam slice of the lunar soil sample in an embodiment of the present application.
[0068] S500. Transfer the focused ion beam slice to the time-of-flight secondary ion mass spectrometer equipment chamber through the ultra-high vacuum pipeline to analyze the elements and their related isotope contents of the cross-section of the focused ion beam slice.
[0069] Finally, the focused ion beam slice can be transferred to the time-of-flight secondary ion mass spectrometer (TOF-SIMS) equipment chamber through the ultra-high vacuum pipeline of the vacuum interconnection system to analyze the contents of various elements and their related isotopes of the cross-section of the focused ion beam slice, and complete the characterization analysis of the lunar soil sample.
[0070] Please refer to Figure 6 , Figure 6 which is the TOF-SIMS analysis image of the cross-section of the focused ion beam slice of the lunar soil sample in an embodiment of the present application.
[0071] Based on the above lunar soil material characterization method, multi-technique combined characterization analysis can be realized for the same area of the same sample, and the obtained characterization results can be effectively correlated with each other to ensure the accuracy of the detection results.
[0072] At the same time, the lunar soil sample is in an ultra-high vacuum environment throughout the detection process, without being disturbed by the atmospheric environment, which can avoid the change of the intrinsic properties of the lunar soil sample and ensure the effectiveness of the detection results.
[0073] In addition, the loss of the sample is extremely small during the whole detection process, avoiding damage to precious lunar soil samples.
[0074] For those skilled in the art, it is obvious that the present application is not limited to the details of the above-described exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present application is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present application. Any reference signs in the claims should not be construed as limiting the claims concerned.
[0075] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for characterizing lunar soil materials based on vacuum interconnection, characterized in that, Including: Embedding and fixing the lunar soil sample on a sample carrier in a glove box; Transferring the sample carrier to the chamber of a scanning electron microscope through an ultra-high vacuum pipeline, performing EDS energy spectrum analysis on the lunar soil sample, and screening to obtain a target detection area; Transferring the sample carrier to the chamber of an X-ray photoelectron spectrometer through an ultra-high vacuum pipeline, and performing elemental analysis on the target detection area; Transferring the sample carrier to the chamber of a focused ion beam device through an ultra-high vacuum pipeline, performing ion beam sectioning on the target detection area to obtain a focused ion beam section; Transferring the focused ion beam section to the chamber of a time-of-flight secondary ion mass spectrometer through an ultra-high vacuum pipeline, and analyzing the elemental and related isotope contents of the cross-section of the focused ion beam section.
2. The method for characterizing lunar soil materials according to claim 1, wherein The step of embedding and fixing the lunar soil sample on the sample carrier in the glove box is: embedding and fixing the lunar soil sample on the sample carrier using indium material.
3. The method for characterizing lunar soil materials according to claim 2, wherein The sample carrier is a silicon wafer.
4. The method for characterizing lunar soil materials according to claim 1, wherein The step of performing EDS energy spectrum analysis on the lunar soil sample and screening to obtain a target detection area is specifically: based on the results of EDS energy spectrum analysis, screening the area with the most abundant target elements as the target detection area.
5. The lunar soil material characterization method according to claim 4, wherein The target element is Fe element.
6. The method for characterizing lunar soil materials according to claim 1, wherein The step of transferring the sample carrier to the chamber of an X-ray photoelectron spectrometer through an ultra-high vacuum pipeline and performing elemental analysis on the selected target detection area is specifically: Performing XPS analysis on the target detection area to obtain the elemental and valence state information on the surface of the target detection area.
7. The method for characterizing lunar soil materials according to claim 6, wherein The step of transferring the sample carrier to the chamber of an X-ray photoelectron spectrometer through an ultra-high vacuum pipeline and performing elemental analysis on the selected target detection area further includes: Performing etching at multiple different depths on the target detection area, and performing XPS analysis on the surface exposed inside the target detection area after each etching to obtain the valence state change information of the target element at different depths in the target detection area.
8. The lunar soil material characterization method according to claim 7, characterized in that In the step of performing etching at multiple different depths on the target detection area, the etching is specifically Ar ion etching.
9. The method for characterizing lunar soil materials according to claim 1, wherein The thickness of the focused ion beam section is 90 - 110 nm.
10. The method for characterizing lunar soil materials according to claim 1, wherein, Before the step of transferring the focused ion beam section to the chamber of a time-of-flight secondary ion mass spectrometer through an ultra-high vacuum pipeline, it further includes: Using an in-built scanning electron microscope in the focused ion beam device chamber to image the cross-section of the focused ion beam section.