A lateral scanning tunneling microscope and scanning imaging method

Abstract

This application belongs to the field of scanning probe microscopy technology, and particularly relates to a transverse scanning tunneling microscope and a scanning imaging method. The scanning tunneling microscope body includes a base, a first piezoelectric tube, a guide rail, a scanning imaging unit, and a sample stage. The fixed end of the first piezoelectric tube is fixedly mounted on the base; the free end of the first piezoelectric tube is fixedly connected to the lower surface of the guide rail. The sample stage is perpendicular to the guide rail and fixedly mounted at one end of the upper surface of the guide rail. The scanning imaging unit is placed on the upper surface of the guide rail. A probe is provided on the scanning imaging module, with the probe tip pointing towards the sample fixed on the sample stage. The scanning imaging unit drives the probe to perform insertion, retraction, or scanning imaging relative to the sample stage while the magnetic field direction is parallel to the sample surface. This application enables efficient scanning imaging of the sample surface when the magnetic field direction is parallel to the sample surface.

Description

Technical Field

[0001] This application belongs to the field of scanning probe microscopy technology, and particularly relates to a transverse scanning tunneling microscope and scanning imaging method. Background Technology

[0002] Scanning tunneling microscopy (STM), with its unique atomic-level spatial resolution and high sensitivity to local electronic state density, has played a crucial role in quantum materials research, and is widely used for fine-grained detection of electronic structure, intrinsic order, and topological properties. As a core component of the STM system, the design of the microscope structure not only lays the foundation for the instrument's intrinsic resolution but also largely determines its adaptability to external experimental conditions (such as extremely low temperatures and strong magnetic fields) and its potential for functional expansion.

[0003] Currently, most commercially available STM mirrors employ out-of-plane magnetic field configurations, meaning the magnetic field direction is perpendicular to the sample surface. While this configuration demonstrates stability in perpendicular field experiments, its ability to support in-plane magnetic fields is relatively limited when dealing with highly anisotropic quantum materials. This results in a lack of high-resolution real-space imaging verification for some theoretically predicted transverse magnetic field-induced phenomena. Although vector magnet technology can provide a certain degree of transverse magnetic field manipulation, it still faces some limitations in practical applications. These include high system costs, and the transverse field strength being affected by factors such as inter-coil stress, thermal effects, and multi-power supply coupling, generally not exceeding 5T. This makes it difficult to fully meet the needs of fine-grained research on strongly correlated electron systems under higher in-plane magnetic field conditions.

[0004] Therefore, how to efficiently scan and image the sample surface when the magnetic field direction is parallel to the sample surface has become an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a transverse scanning tunneling microscope that can efficiently scan and image the sample surface when the magnetic field direction is parallel to the sample surface.

[0006] To achieve the above objectives, this application adopts the following technical solution: A transverse scanning tunneling microscope includes a base, a first piezoelectric tube, a guide rail, a scanning imaging unit, and a sample stage. The fixed end of the first piezoelectric tube is fixedly mounted on the base. The free end of the first piezoelectric tube is fixedly connected to the lower surface of the guide rail. The sample stage is perpendicular to the guide rail and fixedly mounted at one end of the upper surface of the guide rail. The scanning imaging unit is placed on the upper surface of the guide rail. The scanning imaging module is equipped with a probe, the probe tip of which faces the sample fixed on the sample stage. The scanning imaging unit drives the probe to perform insertion, retraction, or scanning imaging relative to the sample stage in a magnetic field direction parallel to the sample surface.

[0007] Preferably, the scanning imaging unit includes a scanning piezoelectric tube, a probe holder, and a sleeve; the scanning piezoelectric tube and the sleeve are nested inside and outside; the fixed end of the scanning piezoelectric tube is fixedly connected to the inner wall of one end of the sleeve; the free end of the scanning piezoelectric tube extends out of the sleeve from the other end of the sleeve or retracts into the sleeve from the other end of the sleeve; a probe holder is provided on the free end of the scanning piezoelectric tube, and a probe is fixed on the probe holder; the outer surface of the sleeve is in contact with the upper surface of the guide rail; the scanning imaging unit and the sample stage are arranged in pairs, and the free end of the scanning piezoelectric tube drives the probe on the probe holder to perform insertion, retraction, or scanning imaging relative to the sample stage.

[0008] Preferably, a limiting piece is fixedly provided at the top of the sample stage in the vertical direction.

[0009] Preferably, the microscope body includes two pairs of scanning imaging units and a sample stage, and the guide rail frame includes two upper and lower guide rail layers that are fixedly connected; each guide rail layer is provided with a pair of scanning imaging units and a sample stage, and the two pairs of scanning imaging units and sample stages are oriented in opposite directions.

[0010] Preferably, the microscope body includes a connector, two pairs of scanning imaging units, and a sample stage; the two scanning imaging units are arranged vertically and in opposite directions; the two sides of the connector are respectively fixed to the outer wall of the sleeve of the two scanning imaging units; the outer surface of the sleeve of the lower scanning imaging unit is in contact with the upper surface of the guide rail; the sample stage is set on the guide rail at the end opposite to the probe on the scanning imaging unit.

[0011] Preferably, the microscope body includes two pairs of scanning imaging units and a sample stage, and the guide rail frame includes two upper and lower guide rail layers that are fixedly connected; each guide rail layer is provided with a pair of scanning imaging units and a sample stage, and the two pairs of scanning imaging units are perpendicular to each other in the direction of extending their own length; the transverse scanning tunneling microscope also includes a magnet cavity, a signal acquisition module and a computer, the microscope body and the magnet cavity are electrically connected to the signal acquisition module, the signal acquisition module and the computer are electrically connected, and the magnet cavity is used to create a magnetic field environment for the microscope body.

[0012] This application also provides a scanning imaging method applied to a transverse scanning tunneling microscope as described above, comprising the following steps: S1, Needle insertion: When the drive unit receives the needle insertion signal from the signal acquisition module, it drives the probe in the scanning imaging unit to continuously approach the sample stage until the signal acquisition module acquires the tunneling current between the probe and the sample, at which point the needle insertion ends. S2, Scanning Imaging: When the signal acquisition module sends a scanning signal, the driving unit drives the probes in each scanning imaging unit to swing relative to the corresponding sample stage. The probes scan and image the sample surface, and simultaneously obtain the first sample morphology image with the magnetic field direction parallel to the first sample surface and the second sample morphology image with the magnetic field direction perpendicular to the second sample surface. After the scanning imaging is completed.

[0013] S3, Needle retraction: After receiving the needle retraction signal from the signal acquisition module, the drive unit drives the probe in the scanning imaging unit to continuously move away from the sample stage.

[0014] Preferably, in S1: when the free end of the scanning piezoelectric tube in the scanning imaging unit extends to its limit position along its own length direction, and the signal acquisition module still fails to acquire the tunneling current between the probe and the sample, the insertion is stopped; then, after the free end of the current scanning piezoelectric tube retracts to its initial state along its own length direction, the insertion stroke of the free end of the current scanning piezoelectric tube is shortened by the first piezoelectric tube; the initial state of the piezoelectric tube refers to the free end of the piezoelectric tube having no tilt in any direction and retracted to its shortest length.

[0015] Preferably, the first piezoelectric tube shortens the needle advance stroke at the free end of the current scanning piezoelectric tube using any one of the methods from method one to method three; Method 1: The movable end of the first piezoelectric tube is tilted at a set angle toward the direction of the corresponding sample stage, so that the current scanning piezoelectric tube slides along the guide rail on the guide rail frame toward the direction of the corresponding sample stage, thereby shortening the needle advance stroke of the free end of the scanning piezoelectric tube of the scanning imaging unit. Method 2: The movable end of the first piezoelectric tube accelerates and retracts to the set position, causing the entire scanning imaging unit to disengage from the guide rail; at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube tilts at a set angle in the direction of the corresponding sample stage, so that the needle stroke of the free end of the scanning piezoelectric tube of the scanning imaging unit that falls back onto the guide rail is shortened. Method 3: After the first piezoelectric tube's movable end is obliquely thrown towards the sample stage towards the current scanning imaging unit, the movable end of the first piezoelectric tube retracts to a set position and its length direction is vertical, thereby shortening the needle advance stroke of the free end of the scanning piezoelectric tube of the scanning imaging unit that falls back onto the guide rail.

[0016] Preferably, in S3, the needle is retracted by scanning the retraction of the free end of the piezoelectric tube; or the first piezoelectric tube is retracted in any one of the methods four to six. Method 4: The movable end of the first piezoelectric tube is tilted at a set angle away from the corresponding sample stage, so that the entire scanning imaging unit slides along the guide rail on the guide frame away from the sample stage. Method 5: The movable end of the first piezoelectric tube accelerates and retracts to the set position, causing the entire scanning imaging unit to disengage from the guide rail; at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube tilts at a set angle away from the corresponding sample stage, thereby increasing the distance between the tip of the scanning imaging unit that falls back onto the guide rail and the corresponding sample stage. Method 6: After the first piezoelectric tube's movable end is thrown obliquely away from the sample stage, the movable end of the first piezoelectric tube retracts to a set position and its length direction is vertical, thereby increasing the distance between the tip of the scanning imaging unit that falls back onto the guide rail and the corresponding sample stage.

[0017] The beneficial effects of this application are as follows: (1) The transverse scanning tunneling microscope of this application can efficiently scan and image the sample surface when the magnetic field direction is parallel to the sample surface.

[0018] (2) In the microscope body of this application, the needle insertion stroke of the free end of the scanning piezoelectric tube 41 is flexibly shortened by the first piezoelectric tube. On this basis, it is ensured that the scanning unit can enable the signal acquisition module to collect the tunneling current between the probe and the sample during the needle insertion process. This ensures that once the experiment starts, the subsequent scanning imaging can proceed smoothly without the need for technicians to stop the experiment and intervene, thus improving the experimental efficiency.

[0019] (3) The microscope body of this application has a variety of flexible needle removal methods, and the corresponding needle removal method can be flexibly selected according to different needs of safety and rapid needle removal.

[0020] (4) In the microscope body of this application, the height of the scanning imaging unit after it is removed from the guide rail is limited by the limiting plate, which reduces the impact force on the guide rail when the scanning imaging unit falls back, reduces the impact damage to the precision components in the microscope body, and extends the life of the precision components in the microscope body; it also avoids shortening the needle insertion stroke of the free end of the scanning piezoelectric tube too much at once, avoids the needle collision during this process, improves the safety of the operation of shortening the needle insertion stroke of the free end of the scanning piezoelectric tube, and also improves the safety of the needle retraction process through the first piezoelectric tube; furthermore, it ensures that the accuracy of subsequent scanning imaging will not be damaged, and ensures the safety of the experimental process.

[0021] (5) When the scanning imaging unit collides with the limiting plate made of spring sheet, the elastic deformation of the spring sheet can also effectively consume the kinetic energy during the impact. Compared with rigid collision, this elastic collision introduces less mechanical vibration interference into the entire mirror body, which is more conducive to stable scanning imaging in the mirror body and reduces damage to various precision components in the mirror body.

[0022] (6) In the microscope body of this application, when the microscope body includes two scanning imaging units arranged in opposite directions, it is possible to scan and image the two sample surfaces simultaneously with the magnetic field direction parallel to the sample surface, which greatly improves the efficiency of scanning and imaging.

[0023] (7) In the microscope body of this application, since the two scanning imaging units are independent of each other, the mechanical vibration interference generated by any one scanning imaging unit during the scanning imaging process will not affect the other scanning imaging unit, thus improving the imaging quality.

[0024] (8) In the microscope body of this application, when the microscope body includes two scanning imaging units arranged perpendicularly to each other along the length direction: ① The needle insertion direction in the upper scanning imaging unit and the needle insertion direction in the lower scanning imaging unit are perpendicular. The needle insertion stroke adjustment process of each scanning imaging unit is not only independent of each other, but also basically does not interfere with each other. Even if the needle is withdrawn from one scanning imaging unit through the first piezoelectric tube, it will not cause the needle insertion stroke of the free end of the scanning piezoelectric tube in the other scanning imaging unit to be shortened, further improving the safety of the experiment.

[0025] ② By adjusting the needle stroke of each of the two scanning imaging units to a suitable range, the two scanning imaging units can simultaneously scan and image their respective sample surfaces.

[0026] ③ It can simultaneously achieve scanning imaging with the magnetic field direction parallel and perpendicular to the sample surface in the same magnetic field, further improving the scanning imaging efficiency.

[0027] (9) The scanning imaging method of this application can flexibly shorten the needle insertion stroke of the free end of the scanning piezoelectric tube by using the first piezoelectric tube. On this basis, it can ensure that the scanning unit can enable the signal acquisition module to collect the tunneling current between the probe and the sample during the needle insertion process, which ensures that the subsequent scanning imaging can proceed smoothly and improves the experimental efficiency. At the same time, the two scanning units do not interfere with each other, ensuring the imaging quality and stability of each scanning unit. Moreover, the needle withdrawal method is flexible and diverse. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the mirror body in Example 1; Figure 2 This is a cross-sectional view of the mirror body in Example 1; Figure 3 This is a cross-sectional view of the mirror body in Example 2; Figure 4 This is a cross-sectional view of the mirror body in Example 3; Figure 5 This is a cross-sectional view of the mirror body in Example 4.

[0029] The actual correspondence between the reference numerals and component names in this application is as follows: 1. Base; 2. First piezoelectric tube; 3. Guide rail bracket; 4. Scanning imaging unit; 41. Scanning piezoelectric tube; 42. Probe holder; 43. Sleeve; 5. Sample stage; 6. Limiting plate; 7. Connecting parts. Detailed Implementation

[0030] Solutions derived by those skilled in the art through equivalent substitution and conventional reasoning of the technical features of this application without inventive effort all fall within the protection scope of this application.

[0031] When an electric field (i.e., driving voltage) is applied to a piezoelectric tube, its shape or size will change. This is the prior art. In this application, the piezoelectric tube is tubular or cylindrical, with a free end and a fixed end at its two ends, respectively. Since the fixed end of the piezoelectric tube is usually fixed to other components, when the piezoelectric tube deforms, it can be regarded as the free end of the piezoelectric tube deforming relative to the fixed end of the piezoelectric tube (such as elongation, contraction, or oscillation).

[0032] The initial state of a piezoelectric tube refers to the free end of the piezoelectric tube being tilted in no direction and contracted to its shortest length.

[0033] Example 1

[0034] This embodiment provides a transverse scanning tunneling microscope including a microscope body, a magnet cavity, a signal acquisition module, and a computer. Both the microscope body and the magnet cavity are electrically connected to the signal acquisition module, which is in turn electrically connected to the computer. The magnet cavity creates a magnetic field environment, and the microscope body is housed within it. The main innovation of this embodiment lies in the microscope body; therefore, the magnet cavity, signal acquisition module, and computer are not shown in the accompanying drawings.

[0035] In this embodiment, the magnet cavity is a general-purpose dry magnet, and the mirror body is embedded in the magnet body through the inner hole of the magnet body.

[0036] like Figure 1 and Figure 2 As shown, the microscope body includes a base 1, a first piezoelectric tube 2, a guide rail 3, a scanning imaging unit 4, and a sample stage 5. One end of the first piezoelectric tube 2 is a fixed end, and the other end is a free end. The fixed end of the first piezoelectric tube 2 is fixedly mounted on the base 1. The free end of the first piezoelectric tube 2 is fixedly connected to the lower surface of the guide rail 3. The sample stage 5 is perpendicular to the guide rail 3 and is fixedly mounted on one end of the upper surface of the guide rail 3. The scanning imaging unit 4 is placed on the upper surface of the guide rail 3. The scanning imaging unit 4 and the sample stage 5 are arranged in pairs. The scanning imaging unit 4 is equipped with a probe. The sample is fixed to the sample stage 5 by adhesive, and the probe tip faces the sample. The scanning imaging unit 4 drives the probe to perform insertion, retraction, or scanning imaging relative to the sample stage 5.

[0037] The length direction of the guide rail 3 is perpendicular to the length direction of the first piezoelectric tube 2 in its initial state, and the magnetic field direction inside the magnet cavity is parallel to the length direction of the first piezoelectric tube 2 in its initial state; therefore, in this embodiment, the mirror body can perform scanning imaging on the sample surface while the magnetic field direction is parallel to the sample surface.

[0038] The vertical direction is the direction of the magnetic field inside the magnet cavity.

[0039] The direction of the guide rail on the guide rail frame 3 is the same as the length direction of the guide rail frame 3.

[0040] The scanning imaging unit 4 includes a scanning piezoelectric tube 41, a probe holder 42, and a sleeve 43. The scanning piezoelectric tube 41 and the sleeve 43 are nested inside each other. One end of the scanning piezoelectric tube 41 is a fixed end, and the other end is a free end. The fixed end of the scanning piezoelectric tube 41 is fixedly connected to the inner wall of one end of the sleeve 43. The free end of the scanning piezoelectric tube 41 extends out of the sleeve 43 from the other end of the sleeve 43 or retracts into the sleeve 43 from the other end of the sleeve 43. The probe holder 42 is provided on the free end of the scanning piezoelectric tube 41, and a probe is fixed on the probe holder 42. The outer surface of the sleeve 43 is in close contact with the upper surface of the guide rail 3. The free end of the scanning piezoelectric tube 41 drives the probe on the probe holder 42 to perform insertion, retraction, or scanning imaging relative to the sample stage 5.

[0041] The length direction of the first piezoelectric tube 2 in its initial state is perpendicular to the length direction of the scanning piezoelectric tube 41 in its initial state. In this embodiment, the length direction of the first piezoelectric tube 2 in its initial state is parallel to the Z-axis direction, and the length direction of the scanning piezoelectric tube 41 in its initial state is parallel to the X-axis direction.

[0042] During the insertion process, if the signal acquisition module still fails to acquire the tunneling current between the probe and the sample when the free end of the scanning piezoelectric tube 41 extends to its limit along its length direction, the first piezoelectric tube 2 will shorten the insertion stroke of the free end of the scanning piezoelectric tube 41 by retracting it to its initial state along the Z-axis in the following ways: Method 1: The movable end of the first piezoelectric tube 2 is tilted at a set angle toward the sample stage 5, so that the scanning imaging unit 4 slides a distance along the guide rail on the guide rail frame 3 toward the sample stage 5 to shorten the needle advance stroke of the free end of the scanning piezoelectric tube 41.

[0043] Method 2: The movable end of the first piezoelectric tube 2 is directly accelerated and retracted to the set position, or thrown upward (i.e., the movable end of the first piezoelectric tube 2 first extends upward and then accelerates and retracts to the set position) to disengage the scanning imaging unit 4 from the guide rail 3; at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube 2 is tilted at a set angle in the direction of the probe support 42 (or the direction of the corresponding sample stage 5), so that the needle insertion stroke of the free end of the scanning piezoelectric tube 41 of the scanning imaging unit 4, which finally falls back to the guide rail 3, is shortened.

[0044] Method 3: After the movable end of the first piezoelectric tube 2 is obliquely thrown towards the sample stage 5, the movable end of the first piezoelectric tube 2 retracts and its length direction is along the Z-axis, so that the needle stroke of the free end of the scanning piezoelectric tube 41 that finally falls back onto the guide rail 3 is shortened.

[0045] After shortening the insertion stroke of the free end of the scanning piezoelectric tube 41, the free end of the scanning piezoelectric tube 41 extends again along its length towards the sample on the sample stage 5, so that the signal acquisition module can acquire the tunneling current between the probe and the sample.

[0046] Optionally, a limiting piece 6 is fixedly installed at the top of the sample stage 5 in the vertical direction.

[0047] In this embodiment, the limiting piece 6 is a spring piece.

[0048] The presence of the limiting piece 6 restricts the spatial height of the scanning imaging unit 4 after it leaves the guide rail 3 during the process of shortening the free end insertion stroke of the scanning piezoelectric tube 41 using method two or method three. This not only reduces the impact force on the guide rail 3 when the scanning imaging unit 4 falls back, thus reducing impact damage to the precision components inside the lens, but also avoids shortening the free end insertion stroke of the scanning piezoelectric tube 41 too much at once, preventing the needle from colliding during this process; further ensuring that the accuracy of subsequent scanning imaging is not compromised.

[0049] When the scanning imaging unit 4 collides with the spring sheet material limiting plate 6, the elastic deformation of the spring sheet can effectively dissipate the kinetic energy during the impact. Compared with rigid collision, this elastic collision introduces less mechanical vibration interference into the entire mirror body, which is more conducive to stable scanning imaging within the mirror body and reduces damage to various precision components within the mirror body.

[0050] By shortening the needle insertion stroke of the free end of the scanning piezoelectric tube 41 as described above, the signal acquisition module can acquire the tunneling current between the probe and the sample during the needle insertion process, thus entering the scanning imaging process.

[0051] During the scanning imaging process, scanning imaging of the sample surface is achieved by swinging the free end of the scanning piezoelectric tube 41.

[0052] After the scanning imaging is completed, the needle retraction process begins: the needle is retracted by retracting the free end of the scanning piezoelectric tube 41; this method ensures the safety of the needle retraction process.

[0053] Optionally, in this embodiment, the first piezoelectric tube 2 in the endoscope body achieves needle retraction in the following ways: Method 4: The movable end of the first piezoelectric tube 2 is tilted at a set angle away from the sample stage 5, so that the scanning imaging unit 4 slides a distance away from the corresponding sample stage 5 along the guide rail on the guide rail frame 3 to achieve rapid needle retraction.

[0054] Method 5: The movable end of the first piezoelectric tube 2 is directly accelerated and retracted to the set position, or first extended upward and then accelerated and retracted to the set position, so that the scanning imaging unit 4 is disengaged from the guide rail 3; at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube 2 is tilted at a set angle away from the direction of the probe support 42 (or the direction corresponding to the sample stage 5), so that the distance between the tip of the scanning imaging unit 4 and the sample stage 5 when it finally falls back to the guide rail 3 is increased compared with the scanning imaging, thereby achieving rapid needle retraction.

[0055] Method 6: After the movable end of the first piezoelectric tube 2 is obliquely thrown away from the sample stage 5, the movable end of the first piezoelectric tube 2 retracts and its length direction is along the Z-axis, so that the distance between the tip of the scanning imaging unit 4 and the sample stage 5 when it finally falls back onto the guide rail 3 is increased compared with the scanning imaging, thereby realizing rapid needle retraction.

[0056] In this embodiment, the microscope body can achieve scanning imaging with the magnetic field direction parallel to the sample surface through a scanning unit arranged horizontally inside the microscope body.

[0057] In this embodiment, to place the microscope body within the magnet cavity and ensure the magnetic field direction is perpendicular to the sample surface, it's evident that the size difference between the scanning piezoelectric tube 41 and the first piezoelectric tube 2 is significant. Therefore, the placement of the scanning imaging unit 4, to which the scanning piezoelectric tube 41 belongs, on the guide rail 3 before the experiment might be inappropriate (inappropriate meaning the probe travel at the free end of the scanning piezoelectric tube 41 is too large), preventing the detection of tunneling current during the experiment. To address this issue of low experimental efficiency, this embodiment uses the first piezoelectric tube to flexibly shorten the probe travel at the free end of the scanning piezoelectric tube 41. This ensures that the scanning unit can enable the signal acquisition module to collect the tunneling current between the probe and the sample during probe travel, guaranteeing that once the experiment begins, subsequent scanning imaging can proceed smoothly, thus improving experimental efficiency. In existing tunneling scanning microscopes, if the signal acquisition module fails to collect the tunneling current during probe travel, the experiment must be stopped, and technicians must adjust the probe travel (i.e., bring the sample stage closer to the scanning unit) before resuming the experiment and probe travel. In this embodiment, the needle insertion stroke can be directly adjusted through the first piezoelectric tube without the need for technical personnel intervention, which inevitably improves experimental efficiency.

[0058] In this embodiment, the microscope body offers a variety of flexible needle retraction methods, allowing for the selection of the appropriate method based on different needs for safety and rapid needle retraction.

[0059] In this embodiment, the microscope body uses a limiting piece 6 to restrict the height of the scanning imaging unit 4 after it detaches from the guide rail 3. This reduces the impact force on the guide rail 3 when the scanning imaging unit 4 falls back, minimizing impact damage to the precision components inside the microscope and extending their lifespan. It also prevents the insertion stroke of the free end of the scanning piezoelectric tube 41 from being shortened too much at once, avoiding collisions during this process. This improves the safety of shortening the insertion stroke of the free end of the scanning piezoelectric tube 41 and enhances the safety of the needle retraction process via the first piezoelectric tube. Furthermore, it ensures that the accuracy of subsequent scanning imaging is not compromised, guaranteeing the safety of the experimental process.

[0060] Safety here refers to the integrity and safety of the needle tip and the sample surface.

[0061] Optionally, a temperature-changing operation can be performed on the magnet temperature-changing plug-in to change the temperature inside the mirror, allowing the experiment to be conducted at different temperatures.

[0062] Example 2

[0063] This embodiment provides a transverse scanning tunneling microscope, which differs from Embodiment 1 in that the guide rail 3 and the scanning imaging unit 4 in the microscope body are as follows: Figure 3The image shown is a cross-sectional view of the scanning tunneling microscope of this embodiment. The following describes only the technical features and effects that differentiate this embodiment from Embodiment 1; other identical parts will not be repeated. The microscope body includes two pairs of scanning imaging units 4 and a sample stage 5. The guide rail frame 3 includes two upper and lower guide rail layers that are fixedly connected. Each guide rail layer is provided with a pair of scanning imaging units 4 and a sample stage 5, and the two pairs of scanning imaging units 4 and sample stages 5 are arranged in opposite directions. The sample stage 5 is vertically arranged on the guide rail layer and is opposite to the probe tip of the corresponding scanning imaging unit 4.

[0064] It is important to emphasize that the upper guide rail layer in the guide rail frame 3, relative to the lower scanning imaging unit 4, plays a similar role to the limiting piece 6. That is, it can limit the height of the lower scanning imaging unit 4 after it detaches from the upper surface of the lower guide rail layer. This not only reduces the impact force on the lower guide rail layer when the lower scanning imaging unit 4 falls back, thus reducing impact damage to the precision components inside the lens, but also prevents the free end of the lower scanning piezoelectric tube 41 from being shortened too much at once, avoiding the possibility of needle collision during this process; further ensuring that the accuracy of subsequent scanning imaging is not compromised.

[0065] Because the scanning imaging unit 4 on the upper guide rail layer and the scanning unit 4 on the lower guide rail layer are arranged in opposite directions, whether a certain scanning imaging unit 4 fails to collect the tunnel current during the needle insertion process or both scanning imaging units 4 fail to collect the tunnel current during the needle insertion process, it is necessary to use any one of the methods 1 to 3 in Embodiment 1 to shorten the needle insertion stroke of the free end of the scanning piezoelectric tube 41 in the corresponding scanning imaging unit 4.

[0066] It is important to emphasize that shortening the probe travel of the free end of the scanning piezoelectric tube 41 on the upper guide layer can only increase the probe travel of the free end of the scanning piezoelectric tube 41 on the lower guide layer; conversely, shortening the probe travel of the free end of the scanning piezoelectric tube 41 on the lower guide layer can only increase the probe travel of the free end of the scanning piezoelectric tube 41 on the upper guide layer. Therefore, shortening the probe travel of the free end of a certain scanning piezoelectric tube 41 does not pose a possibility of causing the probe on another scanning piezoelectric tube 41 to collide with the probe.

[0067] If both scanning imaging units 4 on the two guide rail layers can collect tunneling current during needle insertion, then in the transverse scanning tunneling microscope of this embodiment, two sample surfaces can be scanned and imaged simultaneously with the magnetic field direction parallel to the sample surface, which greatly improves the efficiency of scanning imaging.

[0068] Of course, this embodiment can also use only a single scanning imaging unit 4 to scan and image a single sample, which provides high experimental flexibility.

[0069] Furthermore, since the two scanning imaging units 4 are independent of each other, the mechanical vibration interference generated by either scanning imaging unit 4 during the scanning imaging process will not affect the other scanning imaging unit 4, thus improving the imaging quality.

[0070] The base 1 and guide rail 3 are made of sapphire material with high thermal conductivity and electrical insulation to improve the shock absorption performance of the mirror body and enable the mirror body to work in harsh environments such as water-cooled magnets. The fixed end of the first piezoelectric tube 2 and the base 1, as well as the fixed end of the scanning piezoelectric tube 41 and the sleeve 43 are fixedly connected by insulating sapphire rings to provide insulation.

[0071] Example 3

[0072] This embodiment provides a transverse scanning tunneling microscope, which differs from Embodiment 2 in the guide rail 3 and the scanning imaging unit 4 in the microscope body, such as... Figure 4 The image shown is a cross-sectional view of the scanning tunneling microscope of this embodiment. The following describes only the technical features and effects that differentiate this embodiment from Embodiment 2; other identical parts will not be repeated. The microscope body includes a connector 7, two pairs of scanning imaging units 4, and a sample stage 5. The guide rail frame 3 has only one guide rail layer. The two scanning imaging units 4 are arranged vertically and in opposite directions.

[0073] Both the upper scanning imaging unit 4 and the lower scanning imaging unit 4 include a scanning piezoelectric tube 41, a probe holder 42, and a sleeve 43. The scanning piezoelectric tube 41 and the sleeve 43 are nested inside and outside each other. One end of the scanning piezoelectric tube 41 is a fixed end, and the other end is a free end. The fixed end of the scanning piezoelectric tube 41 is fixedly connected to the inner wall of one end of the sleeve 43. The free end of the scanning piezoelectric tube 41 extends out of the sleeve 43 from the other end of the sleeve 43 or retracts into the sleeve 43 from the other end of the sleeve 43. A probe holder 42 is provided on the free end of the scanning piezoelectric tube 41, and a probe is fixed on the probe holder 42.

[0074] The two sides of the connector 7 are respectively fixed to the outer wall of the sleeve 43 of the two scanning imaging units 4.

[0075] Optionally, the lower scanning imaging unit 4 includes a scanning piezoelectric tube 41, a probe holder 42, and a sleeve 43: the scanning piezoelectric tube 41 and the sleeve 43 are nested inside and outside each other; one end of the scanning piezoelectric tube 41 is a fixed end, and the other end is a free end; the fixed end of the scanning piezoelectric tube 41 is fixedly connected to the inner wall of one end of the sleeve 43; the free end of the scanning piezoelectric tube 41 extends out of the sleeve 43 from the other end of the sleeve 43 or retracts into the sleeve 43 from the other end of the sleeve 43; a probe holder 42 is provided on the free end of the scanning piezoelectric tube 41, and a probe is fixed on the probe holder 42. One side of the connector 7 is fixed to the outer wall of the sleeve 43 of the upper scanning imaging unit 4, and the fixed end of the scanning piezoelectric tube 41 of the lower scanning imaging unit 4 is fixed to the other side of the connector 7. It should be noted that this optional structure of the lower scanning imaging unit 4 and the corresponding fixing form of the connector 7 are not shown in the accompanying drawings.

[0076] If the tunnel current cannot be collected during the needle insertion process in either the upper or lower scanning imaging unit 4, the needle insertion stroke of the free end of the scanning piezoelectric tube 41 in the corresponding scanning imaging unit 4 can be shortened by using any of the three methods.

[0077] It is important to emphasize that, because the two scanning imaging units 4 in this embodiment are fixedly connected by the connector 7 to form a whole, and only the lower scanning imaging unit 4 is in direct contact with the guide rail 3, Method 1 directly shortens the needle insertion stroke at the free end of the upper scanning piezoelectric tube 41 by sliding the lower scanning imaging unit 4. In Methods 2 and 3, when the limiting member 7 is present, the limiting member 7 also simultaneously restricts the spatial height of the whole formed by the two scanning imaging units 4 after it is detached from the guide rail 3.

[0078] Example 4

[0079] This embodiment provides a transverse scanning tunneling microscope, which differs from Embodiment 2 in the guide rail 3 and the scanning imaging unit 4 in the microscope body, such as... Figure 5 The image shown is a cross-sectional view of the scanning tunneling microscope of this embodiment. The following describes only the technical features and effects that differentiate this embodiment from Embodiment 2; other identical parts will not be repeated. The microscope body includes two pairs of scanning imaging units 4 and a sample stage 5. The guide rail frame 3 includes two fixedly connected upper and lower guide rail layers. Each guide rail layer is equipped with a pair of scanning imaging units 4 and a sample stage 5. The upper scanning imaging unit 4 and the lower scanning imaging unit 4 are perpendicular to each other along their respective lengths. When projected along the Z-axis, the projections of the two scanning imaging units 4 form a cross shape. Each sample stage 5 is vertically mounted on the upper surface of the corresponding guide rail layer and is opposite to the probe tip of the corresponding scanning imaging unit 4. The two scanning imaging unit 4 guide rail layers are also included.

[0080] It is important to emphasize that the upper guide rail layer in the guide rail frame 3, relative to the lower scanning imaging unit 4, plays a similar role to the limiting piece 6. That is, it can limit the height of the lower scanning imaging unit 4 after it detaches from the upper surface of the lower guide rail layer. This not only reduces the impact force on the lower guide rail layer when the lower scanning imaging unit 4 falls back, thus reducing impact damage to the precision components inside the lens, but also prevents the free end of the lower scanning piezoelectric tube 41 from being shortened too much at once, avoiding the possibility of needle collision during this process; further ensuring that the accuracy of subsequent scanning imaging is not compromised.

[0081] Because the insertion direction of the upper scanning imaging unit 4 and the lower scanning imaging unit 4 are perpendicular, and each scanning imaging unit 4 is limited by the guide rail layers, the insertion stroke of the free end of one scanning piezoelectric tube 41 will not be changed in the process of reducing the insertion stroke of the free end of the other scanning piezoelectric tube 41, regardless of which method (method 1 to method 3) is used. That is, in this embodiment of the transverse scanning tunneling microscope, the insertion stroke adjustment process of each scanning imaging unit 4 is not only independent of each other, but also basically does not interfere with each other. Furthermore, even if the needle is withdrawn from one scanning imaging unit through the first piezoelectric tube, it will not cause the insertion stroke of the free end of the scanning piezoelectric tube 41 in the other scanning imaging unit to be shortened (or even cause the needle to collide). Therefore, this embodiment of the scanning tunneling microscope further improves the safety of experiments based on embodiments 1 to 3.

[0082] In this embodiment of the transverse scanning tunneling microscope, the two scanning imaging units 4 can be simultaneously scanned and imaged on their respective sample surfaces by adjusting the needle advance strokes of the two scanning imaging units 4 to a suitable range.

[0083] When the magnetic field direction is parallel to one sample surface, the magnetic field direction must be perpendicular to the other sample surface. Therefore, the transverse scanning tunneling microscope of this embodiment can also realize scanning imaging when the magnetic field direction is parallel and perpendicular to the sample surface in the same magnetic field, further improving the scanning imaging efficiency.

[0084] Example 5

[0085] This application also provides a scanning imaging method using a transverse scanning tunneling microscope as described in Example 4, comprising the following steps: S1, Needle insertion: When the drive unit receives the needle insertion signal from the signal acquisition module, it drives the probes in each scanning imaging unit 4 to continuously approach the sample stage 5 until the signal acquisition module acquires the tunneling current between the probe and the sample. After the needle insertion is completed, scanning imaging begins.

[0086] S2, Scanning Imaging: When the signal acquisition module sends a scanning signal, the drive unit drives the probes in each scanning imaging unit 4 to swing relative to the corresponding sample stage 5. The probes scan and image the sample surface, simultaneously obtaining a first sample morphology image with the magnetic field direction parallel to the first sample surface and a second sample morphology image with the magnetic field direction perpendicular to the second sample surface. After scanning imaging is completed, the probe retraction process begins.

[0087] S3, Needle retraction: After receiving the needle retraction signal from the signal acquisition module, the drive unit drives the probe in the scanning imaging unit 4 to continuously move away from the sample stage 5.

[0088] In S1, when the free end of a certain scanning piezoelectric tube 41 in the scanning imaging unit 4 extends to its limit position along its own length direction, the signal acquisition module still fails to acquire the tunneling current between the probe and the sample, so the needle insertion stops. Then, after the free end of the current scanning piezoelectric tube 41 retracts to its initial state along its own length direction, the needle insertion stroke of the free end of the current scanning piezoelectric tube 41 is shortened by the first piezoelectric tube 2.

[0089] "Using the first piezoelectric tube 2 to shorten the needle advance stroke at the free end of the current scanning piezoelectric tube 41" includes the following methods: Method 1: The movable end of the first piezoelectric tube 2 is tilted at a set angle toward the corresponding sample stage 5, so that the current scanning piezoelectric tube 41 slides a distance along the guide rail on the guide rail frame 3 toward the corresponding sample stage 5 to shorten the needle advance stroke of the free end of the current scanning piezoelectric tube 41.

[0090] Method 2: The movable end of the first piezoelectric tube 2 is directly accelerated and retracted to the set position, so that the entire scanning imaging unit 4 is disengaged from the guide rail 3; at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube 2 tilts at a set angle in the direction of the corresponding sample stage 5, so that the needle stroke of the free end of the scanning piezoelectric tube 41 of the scanning imaging unit 4 that falls back onto the guide rail 3 is shortened.

[0091] Method 3: After the movable end of the first piezoelectric tube 2 is obliquely thrown towards the direction of the corresponding sample stage 5 to scan the imaging unit 4, the movable end of the first piezoelectric tube 2 retracts and its own length direction is vertical, so that the needle stroke of the scanning piezoelectric tube 41 that finally falls back to the guide rail 3 is shortened.

[0092] In S3, the needle retraction is achieved by scanning the retraction of the free end of the piezoelectric tube 41.

[0093] Optionally, in S3, the needle retraction also includes the following methods based on the first piezoelectric tube 2: Method 4: The movable end of the first piezoelectric tube 2 is tilted at a set angle away from the corresponding sample stage 5, so that the entire scanning imaging unit 4 slides a distance away from the corresponding sample stage 5 along the guide rail on the guide rail frame 3 to achieve rapid needle retraction.

[0094] Method 5: The movable end of the first piezoelectric tube 2 accelerates and retracts to a set position, causing the entire scanning imaging unit 4 to disengage from the guide rail 3. At the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube 2 tilts at a set angle away from the probe support 42, so that the distance between the tip of the scanning imaging unit 4 and the sample stage 5 when it finally falls back onto the guide rail 3 is increased compared to the scanning imaging, thereby achieving rapid needle retraction.

[0095] Method 6: After the movable end of the first piezoelectric tube 2 is thrown obliquely away from the corresponding sample stage 5, the movable end of the first piezoelectric tube 2 retracts and its length direction is vertical, so that the distance between the tip of the scanning imaging unit 4 and the sample stage 5 when it finally falls back onto the guide rail 3 is increased compared with the scanning imaging, thereby realizing rapid needle retraction.

[0096] One scanning imaging method in this embodiment can be achieved by adjusting the needle travel of the two scanning imaging units 4 to a suitable range, and then simultaneously allowing the two scanning imaging units 4 to scan and image their respective sample surfaces.

[0097] The scanning imaging method of this embodiment can simultaneously achieve scanning imaging with the magnetic field direction parallel and perpendicular to the sample surface in the same magnetic field, further improving the scanning imaging efficiency.

[0098] In this embodiment, a scanning imaging method can flexibly shorten the needle insertion stroke of the free end of the scanning piezoelectric tube 41 by using the first piezoelectric tube. On this basis, it can ensure that the scanning unit can enable the signal acquisition module to collect the tunneling current between the probe and the sample during the needle insertion process, ensuring that the subsequent scanning imaging can proceed smoothly and improving experimental efficiency. At the same time, the two scanning units do not interfere with each other, ensuring the imaging quality and stability of each scanning unit.

[0099] In the scanning imaging method of this embodiment, the needle withdrawal method is flexible and diverse, and the corresponding needle withdrawal method can be flexibly selected according to different requirements of safety and rapid needle withdrawal.

[0100] The technologies, shapes, and structures not described in detail in this application are all known technologies.

[0101] The above are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. A transverse scanning tunneling microscope, characterized in that: The mirror body includes a base (1), a first piezoelectric tube (2), a guide rail (3), a scanning imaging unit (4), and a sample stage (5); the fixed end of the first piezoelectric tube (2) is fixedly mounted on the base (1); the free end of the first piezoelectric tube (2) is fixedly connected to the lower surface of the guide rail (3); the sample stage (5) is perpendicular to the guide rail (3) and fixedly mounted on one end of the upper surface of the guide rail (3); the scanning imaging unit (4) is placed on the upper surface of the guide rail (3); a probe is provided on the scanning imaging module (4), with the probe tip facing the sample fixed on the sample stage (5); the scanning imaging unit (4) drives the probe to perform insertion, retraction, or scanning imaging relative to the sample stage (5) in a state where the magnetic field direction is parallel to the sample surface.

2. The transverse scanning tunneling microscope according to claim 1, characterized in that: The scanning imaging unit (4) includes a scanning piezoelectric tube (41), a probe holder (42), and a sleeve (43); the scanning piezoelectric tube (41) and the sleeve (43) are nested inside and outside; the fixed end of the scanning piezoelectric tube (41) is fixedly connected to the inner wall of one end of the sleeve (43); the free end of the scanning piezoelectric tube (41) extends out of the sleeve (43) from the other end of the sleeve (43) or retracts into the sleeve (43) from the other end of the sleeve (43); a probe holder (42) is provided on the free end of the scanning piezoelectric tube (41), and a probe is fixed on the probe holder (42); the outer surface of the sleeve (43) is in contact with the upper surface of the guide rail frame (3); the scanning imaging unit (4) and the sample stage (5) are arranged in pairs, and the free end of the scanning piezoelectric tube (41) drives the probe on the probe holder (42) to perform needle insertion, needle retraction, or scanning imaging relative to the sample stage (5).

3. A transverse scanning tunneling microscope according to claim 1, characterized in that: The sample stage (5) has a limiting piece (6) fixedly installed at the top in the vertical direction.

4. A transverse scanning tunneling microscope according to claim 3, characterized in that: The mirror body includes two pairs of scanning imaging units (4) and a sample stage (5). The guide rail frame (3) includes two upper and lower guide rail layers that are fixedly connected. Each guide rail layer is provided with a pair of scanning imaging units (4) and a sample stage (5), and the two pairs of scanning imaging units (4) and sample stages (5) are in opposite directions.

5. A transverse scanning tunneling microscope according to claim 3, characterized in that: The microscope body includes a connector (7), two pairs of scanning imaging units (4) and a sample stage (5); the two scanning imaging units (4) are arranged vertically and in opposite directions; the two sides of the connector (7) are respectively fixed to the outer wall of the sleeve (43) of the two scanning imaging units (4); the outer surface of the sleeve (43) of the lower scanning imaging unit (4) is in contact with the upper surface of the guide rail (3); the sample stage (5) is set on the guide rail (3) at the end opposite to the probe on the scanning imaging unit (4).

6. A transverse scanning tunneling microscope according to claim 3, characterized in that: The mirror body includes two pairs of scanning imaging units (4) and a sample stage (5). The guide rail frame (3) includes two upper and lower guide rail layers that are fixedly connected. Each guide rail layer is provided with a pair of scanning imaging units (4) and a sample stage (5), and the two pairs of scanning imaging units (4) are perpendicular to each other in the direction of extending their own length. The transverse scanning tunneling microscope also includes a magnet cavity, a signal acquisition module, and a computer. The microscope body and the magnet cavity are electrically connected to the signal acquisition module, and the signal acquisition module is electrically connected to the computer. The magnet cavity is used to create a magnetic field environment for the microscope body.

7. A scanning imaging method, applied to a transverse scanning tunneling microscope as described in claim 6, characterized in that, Includes the following steps: S1, Needle insertion: When the drive unit receives the needle insertion signal from the signal acquisition module, it drives the probe in the scanning imaging unit (4) to continuously approach the sample stage (5) until the signal acquisition module acquires the tunneling current between the probe and the sample and the needle insertion ends. S2, Scanning Imaging: When the signal acquisition module sends a scanning signal, the driving unit drives the probe in each scanning imaging unit (4) to swing relative to the corresponding sample stage (5). The probe scans and images the sample surface, and at the same time obtains the first sample morphology image with the magnetic field direction parallel to the first sample surface and the second sample morphology image with the magnetic field direction perpendicular to the second sample surface. After the scanning imaging is completed. S3, Needle retraction: After receiving the needle retraction signal from the signal acquisition module, the drive unit drives the probe in the scanning imaging unit (4) to move away from the sample stage (5) continuously.

8. A scanning imaging method according to claim 7, characterized in that, In S1: When the free end of the scanning piezoelectric tube (41) in the scanning imaging unit (4) extends to its limit position along its own length direction, the signal acquisition module still fails to acquire the tunneling current between the probe and the sample, so the needle insertion stops; then the free end of the current scanning piezoelectric tube (41) retracts to its initial state along its own length direction, and the needle insertion stroke of the free end of the current scanning piezoelectric tube (41) is shortened by the first piezoelectric tube (2); the initial state of the piezoelectric tube refers to the free end of the piezoelectric tube having no tilt in any direction and being contracted to its shortest length.

9. A scanning imaging method according to claim 8, characterized in that: The first piezoelectric tube (2) shortens the needle advance stroke of the free end of the current scanning piezoelectric tube (41) by any one of the methods from method one to method three; Method 1: The movable end of the first piezoelectric tube (2) is tilted at a set angle toward the direction of the corresponding sample stage (5), so that the current scanning piezoelectric tube (41) slides along the guide rail on the guide rail frame (3) toward the direction of the corresponding sample stage (5), thereby shortening the needle insertion stroke of the free end of the scanning piezoelectric tube (41) of the scanning imaging unit (4). Method 2: The movable end of the first piezoelectric tube (2) is accelerated and retracted to the set position, so that the entire scanning imaging unit (4) is disengaged from the guide rail (3); at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube (2) is tilted at a set angle in the direction of the corresponding sample stage (5), so that the needle stroke of the free end of the scanning piezoelectric tube (41) of the scanning imaging unit (4) that falls back to the guide rail (3) is shortened; Method 3: After the movable end of the first piezoelectric tube (2) is obliquely thrown towards the sample stage (5) to the current scanning imaging unit (4), the movable end of the first piezoelectric tube (2) retracts to the set position and makes its own length direction vertical, so that the needle stroke of the free end of the scanning piezoelectric tube (41) of the scanning imaging unit (4) falling back to the guide rail (3) is shortened.

10. A scanning imaging method according to claim 9, characterized in that: In S3, the needle is withdrawn by scanning the retraction of the free end of the piezoelectric tube (41); or the first piezoelectric tube (2) withdraws the needle in any of the methods four to six. Method 4: The movable end of the first piezoelectric tube (2) is tilted at a set angle away from the corresponding sample stage (5), so that the entire scanning imaging unit (4) slides along the guide rail on the guide rail frame (3) away from the sample stage (5); Method 5: The movable end of the first piezoelectric tube (2) is accelerated and retracted to the set position, so that the entire scanning imaging unit (4) is disengaged from the guide rail (3); at the same time, during the process of accelerating and retracting to the set position, the movable end of the first piezoelectric tube (2) is tilted at a set angle away from the corresponding sample stage (5), so that the distance between the tip of the scanning imaging unit (4) falling back onto the guide rail (3) and the corresponding sample stage (5) increases; Method 6: After the movable end of the first piezoelectric tube (2) is obliquely thrown away from the sample stage (5), the movable end of the first piezoelectric tube (2) retracts to the set position and makes its length direction vertical, so that the distance between the tip of the scanning imaging unit (4) falling back to the guide rail (3) and the corresponding sample stage (5) increases.

Images