Scanning probe microscope and mass spectrometer combined measuring device

Abstract

The invention relates to a scanning probe microscope and mass spectrometer combined measuring device, a scanning probe microscope comprises a probe, a sample table, a scanning driving mechanism and a signal feedback loop system, the combined measuring device comprises a sampling tube connected with the probe and coaxially arranged with the probe, and the sampling tube is connected with the mass spectrometer; and the data acquisition and analysis system is used for acquiring the surface topography information of the sample where the probe is located and the corresponding gas component information, and carrying out real space data coupling on the two information. A sampling tube and a probe are integrated and connected to a mass spectrometer, and the scanning probe microscope and the mass spectrometer are combined for use. The sampling tube and the probe can move synchronously, dynamic information between the surface of a sample and gas is obtained while high-resolution imaging is performed, and deep research on a reaction mechanism of a gas-solid interface is facilitated. By combining the scanning probe microscope with the mass spectrometer, the method can be widely applied to multiple fields of material science, catalytic science, chemistry, biology and the like, and a powerful tool is provided for researching surface phenomena under a complex system.

Description

Technical Field

[0001] The present invention relates to the technical field of physical chemistry and analytical science equipment, and particularly to a combined measurement device of a scanning probe microscope and a mass spectrometer. Background Art

[0002] Scanning Probe Microscope (SPM) technology is an important tool for surface science research, capable of imaging with nanometer or even atomic resolution, revealing the microscopic morphology and physical and chemical properties of the sample surface. Its core principle is to obtain high-resolution surface information through the interaction between the probe and the sample surface.

[0003] Currently, the existing scanning probe microscope technology has the following limitations for detecting the dynamic behavior of the gas-solid interface and in-situ analysis of the surface atmosphere composition: Most scanning probe microscope technologies only provide surface topography and physical properties (such as conductivity, mechanical properties, or magnetic distribution), and cannot directly obtain the chemical information of surface reactions, especially the gas-phase components and reaction species in the dynamic atmosphere. It is difficult to synchronously capture the surface structure changes and chemical composition changes under dynamic reaction conditions (such as high temperature, specific atmosphere). Moreover, the high-resolution imaging of scanning probe microscope technology requires the sample to be in a high vacuum or ultra-high vacuum environment, while many important chemical reactions (such as catalytic reactions, atmosphere-induced surface reconstruction) need to be carried out under specific gas pressure and gas component conditions. In gas-solid interface analysis, it is necessary to collect gas-phase molecular information in a small area around the probe to reflect the local reaction situation on the surface. However, in the existing technology, there are still technical difficulties in the synchronous movement and precise positioning of gas sampling and the probe. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a combined measurement device of a scanning probe microscope and a mass spectrometer, which is used to solve the problem that the existing scanning probe microscope technology can only detect the topography and physical properties of the object surface and cannot obtain the chemical information of the surface reaction of the object.

[0005] To achieve the above object and other related objects, the present invention provides a combined measurement device of a scanning probe microscope and a mass spectrometer. The scanning probe microscope includes a probe, a sample stage, a scanning drive mechanism, and a signal feedback loop system. The combined measurement device includes:

[0006] A sampling tube, connected to the probe and coaxially arranged with the probe. The sampling tube is connected to a mass spectrometer and is used to collect the gas on the sample surface.

[0007] A data acquisition and analysis system, electrically connected to the scanning probe microscope and the mass spectrometer, is used to obtain the surface topography information and the corresponding gas component information of the sample where the probe is located, and couple the surface topography information and the gas component information data.

[0008] Optionally, the sampling tube is a conical sampling tube. The small-diameter end of the sampling tube is connected to the probe, and the large-diameter end is connected to the mass spectrometer through a gas pipeline. A sampling port is provided on the side wall of the sampling tube close to the small-diameter end along the axial direction, and the sampling port is used to collect the gas on the surface of the sample.

[0009] Optionally, a filter is detachably connected to the sampling tube, and the filter corresponds to the position of the sampling port.

[0010] Optionally, the diameter of the small-diameter end is 1 nm to 1 μm; the diameter of the large-diameter end is 10 mm to 100 mm; the diameter of the sampling port is 100 nm to 1 μm.

[0011] Optionally, a vibration isolation module and an air flow shock absorption module are further included. The vibration isolation module is used to isolate the vibration interference of the pump group of the scanning probe microscope and the environmental vibration, and the air flow shock absorption module is used to reduce the vibration interference of the gas flow during sampling of the sampling tube.

[0012] Optionally, the vibration isolation module includes an air suspension platform and a corrugated hose. The scanning probe microscope is installed on the air suspension platform; the corrugated hose is installed between the pump group of the scanning probe microscope and the microscope cavity.

[0013] Optionally, the air flow shock absorption module includes a voltage stabilizing component and a flow guiding component. The voltage stabilizing component and the flow guiding component are both installed on the gas pipeline and are located at a position on the gas pipeline close to the scanning driving component along the length direction.

[0014] Optionally, the data acquisition and analysis system includes a signal processing module and a data fusion module. The signal processing module is used to record and analyze the position of the probe and the interaction signal between the probe and the surface of the sample corresponding thereto; the data fusion module is used to perform spatial position correspondence on the topography data of the sample surface and the gas component data, and generate a mapping diagram of the sample surface topography and the gas composition on the sample surface.

[0015] Optionally, the signal feedback loop system includes a feedback control module. The feedback control module is used to monitor the interaction signal between the probe and the surface of the sample, and control the scanning driving mechanism to drive the probe to move in three axes to maintain the constancy of the interaction signal between the probe and the surface of the sample.

[0016] Optionally, the signal feedback loop system is electrically connected to the sample stage, the probe, and the scanning drive mechanism; the signal feedback loop system further includes a high-precision adjustable power supply and a preamplifier. The high-precision adjustable power supply is used to control the bias voltage between the probe and the sample; the preamplifier is used to amplify the tunneling current signal between the probe and the sample; the feedback control module is used to receive the tunneling current signal and control the scanning drive mechanism to drive the probe to move in three axes to adjust the distance between the probe and the sample surface.

[0017] As described above, the present invention has the following beneficial effects: By connecting a sampling tube to the probe, the sampling tube can move synchronously with the probe. At the same time, the sampling tube is coaxially arranged with the probe, avoiding a large space occupation of the microscope cavity by integrating the sampling tube on the probe; By connecting the sampling tube to the mass spectrometer, the combination of the scanning probe microscope and the mass spectrometer is realized. The scanning probe microscope can clearly obtain the topography information of the sample surface, and the design of coaxially connecting the sampling tube with the probe and connecting it to the mass spectrometer enables the mass spectrometer to collect and analyze the gas on the sample surface, breaking through the limitations of traditional single instruments, allowing researchers to simultaneously obtain the gas composition information at the corresponding positions of the sample while observing the topography of the sample surface, constructing the dynamic information between the topography and chemical composition of the sample surface, and realizing the comprehensive analysis of the sample surface at the microscale, which helps to deeply study the reaction mechanism of the gas-solid interface. Through the electrical connection of the data acquisition and analysis system with the scanning probe microscope and the mass spectrometer, the topography data and gas composition data of the sample surface are spatially corresponded, so as to intuitively display the topographical and chemical correspondence of the sample surface. The technical solution proposed in this application by combining the scanning probe microscope and the mass spectrometer can be widely applied to multiple fields such as materials science, catalytic science, chemistry, and biology, providing a powerful tool for studying surface phenomena under complex systems. Description of the Drawings

[0018] Figure 1 It shows a schematic diagram of the overall structure of the combined measurement device of the scanning probe microscope and the mass spectrometer shown in the embodiment of the present application;

[0019] Figure 2 It shows a schematic circuit diagram of the scanning tunneling microscope shown in the embodiment of the present application;

[0020] Figure 3 It shows a schematic cross-sectional structure diagram of the probe, the sampling tube, and the scanning drive mechanism shown in the embodiment of the present application;

[0021] Figure 4 It shows a schematic diagram of the motion state of the probe and the sampling tube shown in the embodiment of the present application.

[0022] Description of the Reference Numerals

[0023] Probe 1, sample stage 2, scanning drive mechanism 3, signal feedback loop system 4, sampling tube 5, sampling port 501, airflow shock absorption module 6, vibration isolation module 7, microscope cavity 8, mass spectrometer 9, differential pumping system 10, data acquisition and analysis system 11. Detailed implementation

[0024] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] Please refer to Figures 1 to 4 . It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex. The structures, proportions, sizes, etc. shown in the diagrams of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have technical substantive significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of description and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0026] Before describing the embodiments of the present invention in detail, the application environment of the present invention is first described. The technology of the present invention is mainly applied to the technical field of physical chemistry and analytical science equipment. The present invention is used to solve the problem that the existing scanning probe microscope technology can only detect the surface topography and physical properties of an object and cannot obtain the chemical information of the surface reaction of the object.

[0027] Please combine Figures 1 to 4 As shown, the present invention provides a combined measurement device of a scanning probe microscope and a mass spectrometer. The scanning probe microscope includes a probe 1, a sample stage 2, a scanning drive mechanism 3, and a signal feedback loop system 4.

[0028] In an exemplary embodiment of the present application, the combined measurement device of a scanning probe microscope and a mass spectrometer includes:

[0029] A sampling tube 5, which is connected to the probe 1 and coaxially arranged with the probe 1. The sampling tube 5 is connected to a mass spectrometer 9, and the sampling tube 5 is used to collect the gas on the surface of the sample;

[0030] A data acquisition and analysis system 11, which is electrically connected to the scanning probe microscope and the mass spectrometer 9, is used to obtain the surface topography information and the corresponding gas composition information of the sample where the probe 1 is located, and couple the surface topography information and the gas composition information data.

[0031] In this embodiment, a scanning probe microscope is used for atomic-level imaging of the sample surface. The probe 1 is driven to move on the sample surface by the scanning drive mechanism 3, and the system can record the surface topography and structural information of the sample. The scanning probe microscope has extremely high spatial resolution and can monitor and adjust the distance between the tip and the sample in real time through the signal feedback loop system 4. The scanning drive mechanism 3 is a piezoelectric ceramic three-dimensional displacement unit. The scanning drive mechanism 3 has two modules, namely a coarse approximation module and a fine approximation module. The coarse approximation (i.e., the external piezoelectric ceramic tube) is used to coarsely adjust the initial position of the probe 1 to the sample. At the same time, the thermal expansion and contraction characteristics of the piezoelectric ceramic are used to offset the dimensional changes of the sample caused by temperature changes, so as to maintain the relative stability of the distance between the probe 1 and the sample. The fine approximation (i.e., the internal piezoelectric ceramic tube) is used as a fine scanner to control the three-dimensional movement of the probe 1 in the micron or even nanometer scale. The mass spectrometer 9 is used to analyze the gas components collected from the local area of the sample surface in real time. The mass spectrometer 9 includes a gas mixing chamber, a quadrupole system, and a vacuum system, and can provide quantitative chemical information and is used to reveal the interaction between the material surface and the gas phase. By connecting the sampling tube 5 to the probe 1, the sampling tube 5 can move synchronously with the probe 1. At the same time, the sampling tube 5 is coaxially arranged with the probe 1 to avoid a large space occupation of the microscope cavity 8 caused by integrating the sampling tube 5 on the probe 1. By connecting the sampling tube 5 to the mass spectrometer 9, the scanning probe microscope and the mass spectrometer 9 are combined. The scanning probe microscope can clearly obtain the topography information of the sample surface, and the design of coaxially connecting the sampling tube 5 to the probe 1 and connecting it to the mass spectrometer 9 enables the mass spectrometer 9 to collect and analyze the gas on the sample surface, breaking through the limitations of traditional single instruments, allowing researchers to simultaneously obtain the gas component information at the corresponding position of the sample while observing the topography of the sample surface, constructing the dynamic information between the topography and chemical composition of the sample surface, realizing the comprehensive analysis of the sample surface at the microscale, and helping to deeply study the reaction mechanism of the gas-solid interface. Through the electrical connection of the data acquisition and analysis system 11 with the scanning probe microscope and the mass spectrometer 9, the surface topography data and gas component data of the sample are spatially corresponded, so as to intuitively display the topographic and chemical correspondence relationship of the sample surface. The technical solution proposed in this application combines the scanning probe microscope with the mass spectrometer 9 and can be widely applied to multiple fields such as materials science, chemistry, and biology, providing a powerful tool for studying surface phenomena under complex systems.

[0032] It should be noted that the material of the probe 1 can be selected according to experimental requirements, including iridium, tungsten, nickel, etc., to enhance the tip stability and resolution ability. The sampling tube 5 is made of inert materials resistant to chemical corrosion (such as titanium, quartz, or polytetrafluoroethylene) to adapt to various gas environments.

[0033] In an exemplary embodiment of the present application, the sampling tube 5 is a conical sampling tube 5. The small-diameter end of the sampling tube 5 is connected to the probe 1, and the large-diameter end is connected to the mass spectrometer 9 through a gas pipeline. A sampling port 501 is provided on the side wall of the sampling tube 5 near the small-diameter end along the axial direction, and the sampling port 501 is used to collect the gas on the surface of the sample.

[0034] In this embodiment, the sampling tube 5 is used to collect the gas in a local area on the surface of the sample. The sampling tube 5 is designed to have a conical structure with a thinner front and a thicker rear to reduce the dead volume effect. The inner diameter of the front end (i.e., the small-diameter end) of the sampling tube 5 is less than 1 micron, and it is directly connected to the rear of the probe 1 through a high-vacuum adhesive. A sampling port 501 with a diameter of 100 nanometers to 1 micron is provided on the side wall of the sampling tube 5 for precise sampling. The inner diameter of the rear end (i.e., the large-diameter end) is greater than 1 millimeter, and it is connected to the gas pipeline for efficiently transporting the collected gas to the mass spectrometer 9. The sampling tube 5 and the probe 1 are integrated, and relative fixed movement with the probe 1 is achieved, so as to precisely collect the gas components in a local area on the surface of the sample and synchronously obtain the high-resolution surface topography imaging, thereby revealing the dynamic behavior of the gas-solid interface.

[0035] In an exemplary embodiment of the present application, a filter is detachably connected to the sampling tube 5, and the filter corresponds to the position of the sampling port 501.

[0036] In this embodiment, a replaceable micro-filter is provided on the sampling tube 5 to filter the aerosol particles in the collected gas to ensure the purity of the sampled gas; through the detachable connection design between the filter and the sampling tube 5, researchers can quickly replace the filter.

[0037] In an exemplary embodiment of the present application, the diameter of the small-diameter end is 1 nm to 1 μm; the diameter of the large-diameter end is 10 mm to 100 mm; the diameter of the sampling port 501 is 100 nm to 1 μm.

[0038] In this embodiment, the tip diameter of the probe 1 of the scanning probe microscope is usually between 0.1 nanometer and dozens of nanometers, while the tail diameter of the probe 1 is usually between dozens of micrometers and hundreds of micrometers; for example, for the probe 1 of an atomic force microscope used for observing the surface topography of ordinary materials, the tip diameter may be about 5-10 nanometers; for some applications with high resolution requirements, such as observing biological macromolecules or nanostructures, the tip diameter may be even smaller, reaching 2-5 nanometers; while the tip diameter of the probe 1 of the scanning tunneling microscope is usually at the atomic scale, about 0.1-0.5 nanometers. Since the scanning tunneling microscope obtains surface information by detecting the tunneling current between the probe 1 and the sample surface, the tip needs to be very sharp to achieve atomic-level resolution in order to distinguish the undulations of individual atoms on the sample surface. Its probe 1 tail diameter is also in the range of dozens of micrometers to hundreds of micrometers, similar to the tail diameter of the atomic force microscope probe 1, generally about 50-300 micrometers, mainly for connection and fixation with the scanning drive mechanism 3 and the electronics system of the microscope to ensure that the probe 1 can accurately position and scan the sample surface. Therefore, in order to accurately obtain the gas information of a specific tiny area on the sample surface, the small-diameter end of the sampling tube 5 needs to be as close as possible to the tiny features on the sample surface. The diameter of the small-diameter end of the sampling tube 5 is designed between 1 nm and 1 μm, so that the sampling port 501 opened near the small-diameter end on the sampling tube 5 can focus on an extremely small area of the sample surface. For example, it can sample the gas near a single nanoparticle or a biological molecule, thereby realizing high-spatial-resolution gas composition analysis, which helps to study the local chemical properties and reaction conditions of the sample surface in more detail. The mass spectrometer 9 usually requires a certain gas flow rate and pressure to work properly. The large-diameter end is designed to be 10 mm-100 mm, which can ensure that enough gas is transported into the mass spectrometer 9; moreover, the larger diameter can provide a larger gas channel cross-sectional area, reducing the resistance of the gas during transmission, and ensuring that the gas collected from the sampling port 501 can be quickly and smoothly transported into the mass spectrometer 9 for analysis, improving the response speed and measurement efficiency of the entire combined measurement device. The sampling port 501 is designed with a diameter of 100 nm-1 μm, which can ensure that enough gas for mass spectrometry analysis is collected, and at the same time, it will not introduce too much background gas or cause an obvious change in the gas environment on the sample surface due to excessive sampling volume, thus ensuring that the measurement results can truly reflect the gas composition on the sample surface.

[0039] It is worth noting that the sampling tube 5 shown in the embodiment of the present application is compatible with integrated applications of various types of scanning probe technologies, such as scanning tunneling microscopes, atomic force microscopes, Kelvin probe force microscopes, magnetic force microscopes, and chemical force microscopes, and is used in a variety of material systems (conductive and non-conductive materials) and reaction conditions (high temperature, high pressure or low temperature environments), and has broad application prospects in material characterization and gas-phase reaction research.

[0040] In an exemplary embodiment of the present application, a vibration isolation module 7 and an air flow damping module 6 are further included. The vibration isolation module 7 is used to isolate the pump group of the scanning probe microscope and environmental vibration interference, and the air flow damping module 6 is used to reduce the vibration interference caused by gas flow during sampling of the sampling tube 5.

[0041] In this embodiment, the vibration isolation module 7 isolates the pump group of the scanning probe microscope and the external environment from the probe 1, the sample stage 2, etc. of the measuring device, reducing the transmission of vibration. During operation, the pump group generates vibration. If transmitted to the probe 1 and the sample stage 2, it will cause a slight change in the relative position between the probe 1 and the sample, thus affecting the clarity and accuracy of the scanned image. Movements of personnel in the surrounding environment, operation of nearby machinery and equipment, etc. will also affect the measuring device. By isolating vibration interference, the probe 1 can scan the sample surface more stably, thereby obtaining clearer and more accurate surface topography information. The vibration isolation module 7 can be designed based on an active feedback system, which monitors the cavity vibration in real time and reduces the vibration amplitude by dynamically adjusting the vibration isolation measures. For example, the vibration is detected by a sensor and a counterforce is generated by an actuator to counteract the vibration. When the sampling tube 5 collects the gas on the sample surface, the gas flow will generate a certain impact force, causing the sampling tube 5 and the probe 1 to vibrate. The air flow damping module 6 can reduce the vibration generated by gas flow by optimizing the gas flow path, using a buffer structure or a damping device, etc. For example, a buffer chamber is added to the gas pipeline. After the gas enters the gas pipeline through the sampling tube 5, it is buffered in the buffer chamber first, reducing the impact force of the gas flow; or a damping structure such as porous material is set in the gas pipeline to consume the energy of the gas flow, thereby reducing the vibration.

[0042] In an exemplary embodiment of the present application, the vibration isolation module 7 includes an air suspension platform and a corrugated hose. The scanning probe microscope is installed on the air suspension platform; the corrugated hose is installed between the pump group of the scanning probe microscope and the microscope cavity 8.

[0043] In this embodiment, the air suspension platform uses compressed air to form an air cushion between the platform and the support surface, making the platform in a suspended state, which can effectively buffer and isolate the transmission of external vibration. The air cushion structure can absorb and disperse environmental vibration energy, reducing the vibration transmitted to the scanning probe microscope installed on it, ensuring that the relative position between the probe 1 and the sample can be maintained highly stable, thereby improving the accuracy and resolution of surface topography measurement. During operation, the pump group generates periodic vibration. The corrugated hose has the characteristics of being bendable and flexible. By connecting the pump group and the microscope cavity 8 with the corrugated hose, the vibration generated during the operation of the pump group can be absorbed and buffered, reducing the transmission of vibration to the microscope cavity 8.

[0044] In an exemplary embodiment of the present application, the air flow shock absorption module 6 includes a pressure stabilizing component and a flow guiding component. Both the pressure stabilizing component and the flow guiding component are installed on the gas pipeline and are located at a position on the gas pipeline close to the scanning drive component along the length direction.

[0045] In this embodiment, the pressure stabilizing component includes, but is not limited to, a flow regulator. The pressure stabilizing component can monitor and adjust the gas pressure in real time, so that the pressure of the gas in the pipeline remains relatively stable. When analyzing the gas components on the sample surface, the stable pressure can ensure that the amount of gas collected each time is relatively fixed, making the signal detected by the mass spectrometer 9 more reliable and improving the accuracy of the measurement results. The flow guiding component includes, but is not limited to, a flow guiding plate, a porous medium flow guide or a vortex generator, etc. At the bending of the gas pipeline or where the gas flow velocity changes greatly, installing the flow guiding component can guide the gas flow, make the gas flow smoother, reduce the generation of eddy currents and turbulence, and reduce vibration and noise.

[0046] In an exemplary embodiment of the present application, the data acquisition and analysis system 11 includes a signal processing module and a data fusion module. The signal processing module is used to record and analyze the position of the probe 1 and the interaction signal between the probe 1 and the sample surface; the data fusion module is used to perform spatial position correspondence on the topography data and the gas component data of the sample surface and generate a mapping diagram of the sample surface topography and the gas components on the sample surface.

[0047] In this embodiment, the signal processing module can accurately record the position of the probe 1 during the scanning process, and at the same time monitor and record the interaction signal between the probe 1 and the sample surface in real time. The data fusion module can match the surface topography data at a specific position with the gas component data collected at that position according to the scanning position information of the probe 1, so as to establish an internal connection between the two. After performing spatial position correspondence on the topography data and the gas component data, the data fusion module can generate a mapping diagram of the sample surface topography and the gas components on the sample surface. Researchers can quickly understand the mutual relationship between the physical structure on the sample surface and the chemical reactions involved by observing the mapping diagram, and discover some potential laws and phenomena.

[0048] In an exemplary embodiment of the present application, the signal feedback loop system 4 includes a feedback control module. The feedback control module is used to monitor the interaction signal between the probe 1 and the sample surface and control the scanning drive mechanism 3 to drive the probe 1 to move in three axes to maintain the interaction signal between the probe 1 and the sample surface constant.

[0049] In this embodiment, the sampling tube 5 shown in the embodiment of the present application can be integrally applied with a scanning tunneling microscope, an atomic force microscope, a Kelvin probe force microscope, a magnetic force microscope, etc.

[0050] If the sampling tube 5 is used in combination with a scanning tunneling microscope, the signal feedback loop system 4 monitors the change in the tunneling current between the probe 1 and the sample surface in real time. Based on the monitored tunneling current signal, the feedback control module precisely controls the piezoresistive scanning drive mechanism 3 to adjust the position of the probe 1 in three-dimensional space with a very small step size, so that the tunneling current remains constant, thereby ensuring that the distance between the tip and the sample is always within an appropriate range and achieving high-precision scanning of the sample surface.

[0051] If the sampling tube 5 is used in combination with an atomic force microscope, the signal feedback loop system 4 monitors the interaction force between the atomic force microscope probe 1 and the sample surface. The feedback control module controls the scanning drive mechanism 3 to adjust the tip position so that the interaction force remains at a set constant value, avoiding excessive contact between the tip and the sample surface and damaging the sample or the tip. By recording the height information of the tip at different positions, a three-dimensional topographic image of the sample surface can be constructed.

[0052] If the sampling tube 5 is used in combination with a Kelvin probe force microscope, the signal feedback loop system 4 is mainly used to accurately measure the potential distribution of the sample surface and control the force between the probe 1 and the sample surface to maintain a constant contact or non-contact state, so that while obtaining the surface potential information, the topographic information of the sample surface can also be obtained.

[0053] If the sampling tube 5 is used in combination with a magnetic force microscope, the signal feedback loop system 4 is mainly responsible for detecting the magnetic interaction force between the magnetic tip and the magnetic region on the sample surface. According to the detected magnetic force signal, the feedback control module controls the probe 1 to scan on the sample surface and adjusts the position and height of the probe 1 to maintain the stability of the magnetic interaction force. By recording the magnitude and direction of the magnetic force received by the probe 1 at different positions, a magnetic image of the sample surface can be constructed, revealing information such as the magnetic distribution and magnetic domain structure at the microscopic scale of the sample surface.

[0054] In an exemplary embodiment of the present application, the signal feedback loop system 4 is electrically connected to the sample stage 2, the probe 1, and the scanning drive mechanism 3; the signal feedback loop system 4 further includes a high-precision adjustable power supply and a preamplifier. The high-precision adjustable power supply is used to control the bias voltage between the probe 1 and the sample; the preamplifier is used to amplify the tunneling current signal between the probe 1 and the sample; the feedback control module is used to receive the tunneling current signal and control the scanning drive mechanism 3 to drive the probe 1 to move in three axes to adjust the distance between the probe 1 and the sample surface.

[0055] In this embodiment, the high-precision adjustable power supply can precisely control the magnitude of the bias voltage, enhance the tunneling current signal, and improve the sensitivity and resolution of the measurement; the preamplifier can amplify the tunneling current signal to a level that is easy to detect and process; the feedback control module receives the tunneling current signal and controls the scanning drive mechanism 3 to drive the probe 1 to perform three-axis movement according to the change of the signal, thereby adjusting the distance between the probe 1 and the sample surface, enabling the probe 1 to closely follow the undulation of the sample surface for scanning, achieving high-precision surface topography measurement, and accurately depicting the microscopic structure of the sample surface.

[0056] In another exemplary embodiment, the combined measurement device further includes a differential pumping system 10, and the differential pumping system 10 includes a multi-pass interface and a gas micro-leak valve; the multi-pass interface can be composed of a multi-stage pumping device, and a common multi-stage pumping device includes a molecular pump and a dry pump. The multi-stage pumping devices cooperate with each other to achieve precise separation of different pressure regions. When the combined measurement device of the scanning probe microscope and the mass spectrometer is working, different parts often require different pressure environments. For example, in the in-situ gas experiment, the microscope chamber 8 needs a relatively high pressure to promote the reaction of the sample, while the gas mixing chamber of the mass spectrometer 9 requires an extremely high vacuum to ensure the accuracy of mass spectrometry analysis. The multi-stage pumping device of the multi-pass interface can separately control and adjust according to the pressure requirements of different regions. By reasonably configuring the working parameters of the molecular pump and the dry pump, different pressure regions are isolated, ensuring that each region can reach and maintain the required precise pressure, avoiding mutual interference between different pressure regions, and thus improving the accuracy and reliability of the measurement. The gas micro-leak valve can precisely control the flow rate of the sampled gas, and its high control accuracy (at the level of 10 -3 Pa / s) enables precise adjustment of the gas volume entering the mass spectrometer 9 according to specific experimental requirements and sample characteristics when collecting the gas on the sample surface. In different experimental scenarios and for different sample types, the combined measurement device has different requirements for the vacuum degree. The differential pumping system 10 can dynamically adjust the vacuum degree to adapt to various operating environments from 10 3 Pa (sample chamber) to 10 -6 Pa (mass spectrometry gas mixing chamber). In cases such as sample replacement and change of experimental conditions, the differential pumping system 10 can quickly adjust the vacuum degree of each part to ensure the stable and efficient operation of the combined device, enabling the combined measurement device to be applied to a wider range of experimental research fields and improving the versatility of the device.

[0057] Working principle: In this application, the combination of the sampling tube 5 and the scanning tunneling microscope is taken as an example. First, the experimental sample (such as a copper-based metal sample) is cleaned and installed on the sample stage 2. At the beginning, the distance between the probe 1 and the sample is large, and the tunneling current cannot be measured. The probe 1 is driven by the outer piezoelectric ceramic tube of the scanning drive mechanism 3 for coarse approach until a measurable tunneling current is generated. Subsequently, the signal feedback loop system 4 further finely adjusts the position of the probe 1 according to the tunneling current value to ensure that the distance between the sample surface and the scanning probe 1 is maintained at about 1 nm. The tip of the scanning probe 1 can be made of materials such as tungsten, gold, and platinum-iridium alloy, and the tip radius is less than 10 nm, which can achieve surface imaging under high-resolution conditions. During the experiment, a specific atmosphere is introduced into the microscope cavity 8. The probe 1 starts to scan the sample surface, and the signal feedback loop system 4 adjusts the position of the probe 1 in real time according to the tunneling current feedback information to ensure that the tunneling current remains stable during the imaging process. During the scanning process, the probe 1 moves up and down with the height change of the sample surface, thereby recording the three-dimensional topography information of the sample surface. At the same time, the differential pumping system 10 and the mass spectrometer 9 are kept running. By opening the gas micro-leak valve at the front end of the gas mixing chamber of the mass spectrometer 9, the local atmosphere on the sample surface enters the mass spectrometer 9 through the sampling port 501, and the gas composition of the local area on the sample surface is analyzed in real time. Through the linked signal feedback loop system 4, the scanning probe 1 and the gas sampling system work synchronously to ensure the consistency of the surface imaging and gas analysis data. The gas composition data obtained by the mass spectrometer 9 is synchronously recorded with the imaging results of the scanning tunneling microscope, providing a detailed quantitative analysis of the relationship between the surface gas distribution and the atomic-level structure. Finally, with the help of the integrated data acquisition and analysis system 11, a one-to-one corresponding image containing both surface imaging and gas distribution is generated.

[0058] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A combined measuring device of a scanning probe microscope and a mass spectrometer, the scanning probe microscope comprising a probe, a sample stage, a scanning drive mechanism, and a signal feedback loop system, characterized in that, The combined measurement device includes: A sampling tube, connected to the probe and coaxially arranged with the probe. The sampling tube is connected to a mass spectrometer and is used to collect the gas on the surface of the sample. A data acquisition and analysis system, electrically connected to the scanning probe microscope and the mass spectrometer, for obtaining the surface topography information of the sample where the probe is located and the corresponding gas component information, and coupling the surface topography information and the gas component information data.

2. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 1, characterized in that: The sampling tube is a conical sampling tube. The small-diameter end of the sampling tube is connected to the probe, and the large-diameter end is connected to the mass spectrometer through a gas pipeline. A sampling port is provided on the side wall of the sampling tube near the small-diameter end along the axial direction, and the sampling port is used to collect the gas on the surface of the sample.

3. The measurement device for coupling a scanning probe microscope and a mass spectrometer according to claim 2, characterized in that: A filter is detachably connected to the sampling tube, and the filter corresponds to the position of the sampling port.

4. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 3, characterized in that: The diameter of the small-diameter end is 1 nm to 1 μm; the diameter of the large-diameter end is 10 mm to 100 mm; the diameter of the sampling port is 100 nm to 1 μm.

5. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 1, wherein: It further includes a vibration isolation module and an air flow shock absorption module. The vibration isolation module is used to isolate the pump group of the scanning probe microscope and environmental vibration interference, and the air flow shock absorption module is used to reduce the vibration interference of gas flow during sampling of the sampling tube.

6. The measurement device for coupling a scanning probe microscope and a mass spectrometer according to claim 5, characterized in that: The vibration isolation module includes an air suspension platform and a corrugated hose. The scanning probe microscope is installed on the air suspension platform; the corrugated hose is installed between the pump group of the scanning probe microscope and the microscope cavity.

7. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 5, characterized in that: The air flow shock absorption module includes a voltage stabilizing component and a flow guiding component. The voltage stabilizing component and the flow guiding component are both installed on the gas pipeline and are located at a position on the gas pipeline close to the scanning driving component along the length direction.

8. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 1, characterized in that: The data acquisition and analysis system includes a signal processing module and a data fusion module. The signal processing module is used to record and analyze the position of the probe and the interaction signal between the probe and the surface of the sample; the data fusion module is used to perform spatial position correspondence on the topography data and gas component data of the sample surface and generate a mapping diagram of the sample surface topography and the gas components on the sample surface.

9. The combined measurement device of a scanning probe microscope and a mass spectrometer according to claim 8, wherein: The signal feedback loop system includes a feedback control module. The feedback control module is used to monitor the interaction signal between the probe and the surface of the sample and control the scanning drive mechanism to drive the probe to move in three axes to maintain the constancy of the interaction signal between the probe and the surface of the sample.

10. The combined scanning probe microscope and mass spectrometer measurement device according to claim 9, characterized in that: The signal feedback loop system is electrically connected to the sample stage, the probe, and the scanning drive mechanism; the signal feedback loop system further includes a high-precision adjustable power supply and a preamplifier. The high-precision adjustable power supply is used to control the bias voltage between the probe and the sample; the preamplifier is used to amplify the tunneling current signal between the probe and the sample. The feedback control module is used to receive the tunneling current signal and control the scanning drive mechanism to drive the probe to move in three axes to adjust the distance between the probe and the surface of the sample.

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