Rotary microscope for opposite scanning of coaxial piezoelectric tubes and scanning imaging method

Abstract

The invention belongs to the technical field of scanning probe microscopes, and particularly relates to a rotating microscope for opposite scanning of coaxial piezoelectric tubes and a scanning imaging method. The microscope comprises a rotating mirror body, a magnet cavity, a signal acquisition module and a computer, the rotating mirror body and the magnet cavity are electrically connected with the signal acquisition module, the signal acquisition module is electrically connected with the computer, and the magnet cavity creates a magnetic field environment; the rotating mirror body comprises a mirror body and a rotating module which are arranged in the magnet cavity, the mirror body is fixed on the rotating module, and the rotating module can drive the mirror body to rotate; the endoscope body comprises a scanning imaging unit and a driving unit, the scanning imaging unit comprises a sample table and a probe, the driving unit comprises two piezoelectric tubes, and the sample table and the probe are fixedly arranged at the free ends of the two piezoelectric tubes respectively; and the free ends of the two piezoelectric tubes drive the probe to perform probe insertion, probe withdrawal or scanning imaging relative to the sample table. According to the invention, high-quality and stable scanning imaging can be carried out on a sample in a high-intensity magnetic field, and the experiment efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of scanning probe microscopes, and particularly relates to a coaxial piezoelectric tube opposite scanning rotary microscope and a scanning imaging method. BACKGROUND

[0002] Both scanning tunneling microscopes (STM) and magnetic force microscopes (MFM) belong to scanning probe microscopes. As a core characterization tool for the study of the microstructure of magnetic materials, the conventional working mode of scanning probe microscopes relies on the out-of-plane magnetic field configuration (the magnetic field direction is perpendicular to the sample surface), and the magnetic field direction cannot be dynamically adjusted during the test process. This limitation seriously hinders the systematic study of the characteristics of magnetic anisotropy materials (such as giant magnetoresistance effect, phase separation, and ferroelectricity), and also leads to an observation blind area of some anisotropy-related physical phenomena.

[0003] To solve this problem, the prior art uses a superconducting vector magnet to synthesize a magnetic field in any direction through a plurality of superconducting coils arranged orthogonally, but the multi-coil system and its independent control power supply significantly increase the cost, and the non-principal axis direction magnetic field strength is limited due to the mechanical stress of the coil. The upper limit of the transverse magnetic field of the current commercial system is only 5T, which is difficult to meet the needs of scanning probe microscopes to conduct experiments in a high-strength magnetic field.

[0004] In addition, the resonance of the scanning frame of the scanning probe microscope, the noise of the mechanical and electrical components, etc. can cause mechanical vibration, and during the working process, thermal drift, thermal fluctuations are also transmitted to the scanning unit of the microscope body, and the strong magnetic field environment can further directly or indirectly interfere with the needle insertion and needle withdrawal process of the probe, and affect the stability and precision of the scanning imaging. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a coaxial piezoelectric tube opposite scanning rotary microscope, which can meet the needs of scanning probe microscopes to conduct experiments in a high-strength magnetic field, and can perform high-quality and stable scanning imaging on samples in a high-strength magnetic field, and improve the experimental efficiency.

[0006] To achieve the above purpose, the present application adopts the following technical solutions: The application discloses a coaxial piezoelectric tube opposite scanning rotary microscope, which comprises a rotary mirror body, a magnet cavity, a signal acquisition module and a computer, wherein the rotary mirror body and the magnet cavity are electrically connected with the signal acquisition module, the signal acquisition module is electrically connected with the computer, and the magnet cavity generates a magnetic field environment; the rotary mirror body comprises a mirror body and a rotating module arranged in the magnet cavity, the mirror body is fixed on the rotating module, and the rotating module can drive the mirror body to rotate; the mirror body comprises a scanning imaging unit and a driving unit, the scanning imaging unit comprises a sample table and a probe, and the driving unit comprises two piezoelectric tubes, the sample table and the probe are fixedly arranged at free ends of the two piezoelectric tubes respectively; the two piezoelectric tubes drive the probe to move towards or away from the sample table or to scan and image relative to the sample table.

[0007] Preferably, the mirror body further comprises a first base, and the two piezoelectric tubes are respectively referred to as a first piezoelectric tube and a second piezoelectric tube; the fixed end of the first piezoelectric tube and the second piezoelectric tube are arranged in a nested mode, and the fixed ends of the first piezoelectric tube and the second piezoelectric tube are fixed on the first base.

[0008] Preferably, the length of the second piezoelectric tube is always longer than that of the first piezoelectric tube, the free end of the second piezoelectric tube is closed, and the free end of the first piezoelectric tube is arranged in the second piezoelectric tube; the probe is arranged at the free end of the second piezoelectric tube and has a needle tip facing the sample table; the sample table is arranged at the free end of the first piezoelectric tube; the sample faces the probe and is fixed on the sample table.

[0009] Preferably, the scanning imaging unit further comprises a probe support fixedly arranged at the free end of the second piezoelectric tube; the probe is fixedly arranged on the probe support and has a needle tip facing the sample table; the sample table is arranged at the free end of the first piezoelectric tube; the sample faces the probe and is fixed on the sample table.

[0010] Preferably, the scanning imaging unit further comprises a slide rod arranged in the free end of the first piezoelectric tube in a nested mode; one end of the slide rod is arranged inside the free end of the first piezoelectric tube, the other end of the slide rod is arranged outside the first piezoelectric tube and faces the probe; and the outer wall of the slide rod is in extrusion contact with the inner wall of the first piezoelectric tube.

[0011] Preferably, the scanning imaging unit further comprises a spring sheet fixedly arranged on the outer wall of the slide rod and in extrusion contact with the inner wall of the first piezoelectric tube.

[0012] Preferably, the rotating module comprises a rotating driving device and a clamping piece, the rotating driving device comprises a third piezoelectric tube, a C-shaped spring sheet, a bearing, a rotor and a second base, the third piezoelectric tube comprises a fixed end and a free end, the fixed end of the third piezoelectric tube is fixed on the second base, and the free end of the third piezoelectric tube is fixedly connected with a first end of the C-shaped spring sheet; a second end of the C-shaped spring sheet is in elastic extrusion contact with the bearing at all times; the rotor is arranged in the center of the bearing and is fixedly connected with the clamping piece; and the clamping piece clamps the mirror body.

[0013] Preferably, the rotating module further comprises a pin ring arranged on the mirror body and fixed between the clamping members; a Hall sensor is fixedly arranged on the rotor, and the bearing is continuously regulated in angle after the rotating angle is calibrated according to the resistance indication of the Hall sensor.

[0014] The application further provides a scanning imaging method applied to the coaxial piezoelectric tube opposite scanning rotating microscope. S1, needle insertion: when the two piezoelectric tubes in the driving unit receive the needle insertion signal sent by the signal acquisition module, the probe is continuously driven to approach the sample stage until the needle insertion end signal sent by the signal acquisition module is received; When any of the following conditions occurs, the signal acquisition module sends the needle insertion end signal: ① the signal acquisition module collects the tunneling current between the probe and the sample; ② the signal acquisition module collects the atomic force mutation between the probe and the sample; S2, one-time scanning imaging: when the scanning signal sent by the signal acquisition module, the two piezoelectric tubes in the driving unit drive the probe to move relative to the XY plane of the sample stage, the probe performs one-time scanning imaging on the sample surface to obtain a sample topography image; after the scanning imaging is completed, the needle withdrawal process is entered; S3, needle withdrawal: after the two piezoelectric tubes in the driving unit receive the needle withdrawal signal sent by the signal acquisition module, the probe is continuously driven to move away from the sample stage; when the free end of the piezoelectric tube in the driving unit 13 is retracted to the minimum length of itself or is elongated to the maximum length of itself, the needle withdrawal process is completed.

[0015] Preferably, after S1 and before S2, S1' is further included: S1', manufacturing a full-angle magnetic field environment: the rotating module drives the mirror body to rotate in the magnet cavity.

[0016] The application has the following advantages: (1) The rotating microscope of the application is a scanning probe microscope, the mirror body 1 is driven by the rotating module 2 to manufacture a full-angle magnetic field environment for the scanning imaging of the sample in the mirror body, and the experimental environment of low temperature and full-angle strong magnetic field is compatible, which can meet the demand of the scanning probe microscope for experiments in a high-strength magnetic field, and can perform high-quality and stable scanning imaging on the sample in the high-strength magnetic field, thereby improving the experimental efficiency.

[0017] (2) In the microscope body of the present invention, the first piezoelectric tube and the second piezoelectric tube, which are nested and coaxially arranged, are used to fix the components in the scanning imaging unit and to confine all the components contained in the microscope body within the second piezoelectric tube. This makes the microscope body structure small and compact, and can be directly embedded in a universal dry magnet to achieve 360° continuous rotation, with strong compatibility. Therefore, technicians no longer need to worry about the selection of the magnet cavity and can directly use a universal dry magnet, which also reduces the construction cost of the rotating microscope in this embodiment.

[0018] (3) In the microscope body of the present invention, the probe and the sample stage are arranged opposite to each other, and the probe and the sample stage are respectively located on two different piezoelectric tubes, and their positions are only controlled by the corresponding piezoelectric tubes. That is, the purpose of controlling the sample stage to move closer to or away from the probe can be achieved by controlling the extension and retraction of the free end of the first piezoelectric tube alone, or by controlling the extension and retraction of the free end of the second piezoelectric tube alone, or by simultaneously controlling the relative distance between the free ends of the first and second piezoelectric tubes. Therefore, the probe can move closer to or away from the sample stage with high flexibility in the insertion and retraction methods in the microscope body of this embodiment.

[0019] (4) In the microscope body of the present invention, during the scanning imaging process, the degree of offset of the free end of the first piezoelectric tube or the free end of the second piezoelectric tube in the XY plane can be controlled independently to control the position of the probe for scanning imaging on the sample. For samples with a large area, this embodiment can also simultaneously control the free ends of the first and second piezoelectric tubes to offset in opposite directions to quickly achieve full coverage scanning of large-area samples. Therefore, the microscope body of this embodiment can achieve large-area scanning imaging of samples, and the scanning imaging method is highly flexible.

[0020] (5) The microscope of the present invention, while having a small and compact structure, also provides a sufficiently large probe insertion and retraction stroke; and can also achieve large-area scanning imaging of the sample in the second piezoelectric tube.

[0021] (6) In the microscope body of the present invention, the two piezoelectric tubes contained in the drive unit are nested coaxially, and their corresponding fixed ends are both on the first base. Therefore, when mechanical vibrations inside the microscope body are transmitted to these two piezoelectric tubes, the degree, frequency, type, and direction of interference to the two piezoelectric tubes are the same. This makes the relative interference between the free ends of the first and second piezoelectric tubes very small (or even zero). Therefore, the microscope body of this example can effectively suppress the common-mode noise of the drive unit, reduce the thermal drift rate, improve the thermal stability of the drive unit, and further ensure the stability, accuracy, and safety of the probe and sample stage during probe insertion, scanning imaging, and probe retraction.

[0022] (7) Compared with the discontinuous angle control by mechanical gears in the prior art, the rotation module of the present invention can realize continuous control of the rotation angle of the mirror body, which meets the flexibility requirements of technicians for conducting experiments in a high-intensity magnetic field using a scanning probe microscope.

[0023] (8) The rotating module of the present invention indirectly drives the bearing to rotate tangentially through a C-shaped spring plate via a third piezoelectric tube. Because the entire indirect driving process is a flexible transmission, the amplitude of disturbances such as mechanical vibrations will be greatly weakened or even eliminated when transmitted to the C-shaped spring plate due to the deformation of the C-shaped spring plate and the friction between the second end of the C-shaped spring plate and the bearing contact surface. That is, the rotating module of this embodiment can stably and accurately continuously control the rotation angle of the mirror body 1.

[0024] (9) The scanning imaging method of the present invention can create a full-angle magnetic field environment and perform high-quality and stable scanning imaging of the sample in the full-angle magnetic field environment; and greatly reduce the interference inside the microscope lens, enhance the safety when the needle tip approaches and moves away from the sample, while improving the quality and stability of the imaging and improving the experimental efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the rotating mirror structure in Example 1; Figure 2 This is a schematic diagram of the mirror structure in Example 2; Figure 3 This is a bottom view of the slide rod inside the first piezoelectric tube; Figure 4 This is a schematic diagram of the rotary drive device.

[0026] The actual correspondence between the reference numerals and component names in this invention is as follows: 1. Lens body; 11. First base; 12. Scanning imaging unit; 121. Sliding rod; 122. Sample stage; 123. Probe holder; 124. Probe; 125. Spring plate; 13. Drive unit; 131. First piezoelectric tube; 132. Second piezoelectric tube; 2. Rotation module; 21. Rotary drive device; 211. Third piezoelectric tube; 212. C-type spring plate; 213. Bearing; 214. Rotor; 215. Second base; 22. Clamping component; 23. Pin ring. Detailed Implementation

[0027] Solutions derived by those skilled in the art through equivalent substitution and conventional reasoning of the technical features of the present invention without creative effort all fall within the protection scope of the present invention.

[0028] When an electric field (i.e., driving voltage) is applied to piezoelectric tubes, their shape or size will change, which is the prior art. In this invention, 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).

[0029] Example 1 This embodiment of a rotating microscope with coaxial piezoelectric tube counter-scanning includes a rotating mirror body, a magnet cavity, a signal acquisition module, and a computer. Both the rotating mirror 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 rotating mirror body is housed within it. The main innovation of this embodiment lies in the rotating mirror body; therefore, the magnet cavity, signal acquisition module, and computer are not shown in the accompanying drawings.

[0030] In this embodiment, the magnet cavity is a general-purpose dry magnet, and the rotating mirror is embedded in the magnet through the inner hole of the magnet.

[0031] like Figure 1 As shown, the rotating mirror body includes a mirror body 1 and a rotating module 2. The mirror body 1 is fixed on the rotating module 2. The rotating module 2 can drive the mirror body 1 to rotate in a magnetic field environment. This allows for dynamic adjustment of the magnetic field direction relative to the mirror body 1, avoiding the problems of limited magnetic field strength in non-principal axis directions relative to the mirror body 1 and blind spots in the observation of some anisotropic physical phenomena. This is beneficial for the systematic study of the properties of magnetically anisotropic materials (such as giant magnetoresistance, phase separation, and ferroelectricity) and meets the needs of scanning probe microscopes to conduct experiments in high-intensity magnetic fields.

[0032] The mirror body 1 includes a first base 11, a scanning imaging unit 12, and a driving unit 13. One end of the driving unit 13 is a fixed end, and the other end is a free end. The fixed end of the driving unit 13 is fixedly disposed on the first base 11, and the scanning imaging unit 12 is fixedly disposed on the free end of the driving unit 13. The scanning imaging unit 12 includes a sample stage 122 and a probe 124. The free end of the driving unit 13 drives the probe 124 to perform insertion, retraction, or scanning imaging relative to the sample stage 122.

[0033] The sample stage 122 is used to hold the sample. The sample can be fixed to the sample stage 122 by adhesive.

[0034] The driving unit 13 includes a first piezoelectric tube 131 and a second piezoelectric tube 132 nested together. Both the first piezoelectric tube 131 and the second piezoelectric tube 132 have a fixed end and a free end. The fixed ends of both the first piezoelectric tube 131 and the second piezoelectric tube 132 are fixedly mounted on the first base 11. The sample stage 122 is disposed at the free end of the first piezoelectric tube 131. The length of the second piezoelectric tube 132 always exceeds that of the first piezoelectric tube 131. The free end of the second piezoelectric tube 132 is closed, and the probe 124 is directly fixedly mounted on the closed free end of the second piezoelectric tube 132 with its tip facing the sample stage 122. The sample is fixed on the side of the sample stage 122 facing the probe 124.

[0035] Alternatively, the positions of probe 124 and sample stage 122 can be interchanged.

[0036] An insulating sapphire ring, which is fixedly mounted on the first base 11, is used to further fix the fixed ends of the piezoelectric tubes 131 and 132 and to insulate the inner and outer nested piezoelectric tubes.

[0037] The outer electrodes of the first piezoelectric tube 131 and the second piezoelectric tube 132 are both arranged in four quadrants along the axial direction, so that the free ends of the first piezoelectric tube 131 and the second piezoelectric tube 132 can move in the three-dimensional XYZ quadrants.

[0038] Optionally, the first piezoelectric tube 131 and the second piezoelectric tube 132 are arranged coaxially.

[0039] Optionally, the scanning imaging unit 12 further includes a slide rod 121 partially nested within the free end of the first piezoelectric tube 131; one end of the slide rod 121 is located inside the free end of the first piezoelectric tube 131, and the other end of the slide rod 121 is located outside the first piezoelectric tube 131 and faces the probe 124. The outer wall of the slide rod 121 has two or more line contacts with the inner wall of the first piezoelectric tube 131, so that the slide rod 121 is engaged within the first piezoelectric tube 131 by static friction.

[0040] like Figure 3 The image shown is a bottom view of the slide rod 121 inside the first piezoelectric tube 131 in this embodiment, viewed from the movable end of the first piezoelectric tube 131 toward the fixed end. In this embodiment, the slide rod 121 is a hexahedron, meaning that the radial cross-section of the slide rod 121 along the first piezoelectric tube 131 is rectangular. The slide rod 121 is fixed inside the first piezoelectric tube 131 by receiving sufficient static friction through four line contacts with the inner wall of the first piezoelectric tube 131.

[0041] The slide rod 121 can also be elliptical in the radial section of the first piezoelectric tube 131. In this case, the slide rod 121 is fixed inside the first piezoelectric tube 131 by two line contacts with the inner wall of the first piezoelectric tube 131, which allows the slide rod 121 to be subjected to sufficient static friction force.

[0042] Optionally, the scanning imaging unit 12 further includes a spring plate 125; the spring plate 125 is fixedly disposed on the outer wall of the slide rod 121 and is compressed by the inner wall of the first piezoelectric tube 131. While the spring plate 125 is compressed by the inner wall of the first piezoelectric tube 131, the spring plate 125 also applies pressure radially along the first piezoelectric tube 131 towards the outer wall of the slide rod 121. This makes the static friction between the slide rod 121 itself and the inner wall of the first piezoelectric tube 131 at the line contact point greater; furthermore, when the spring plate 125 and the slide rod 121 are considered as a single force-bearing unit, this unit, in addition to the static friction between the slide rod 121 itself and the inner wall of the first piezoelectric tube 131 at the line contact point, also has the static friction between the spring plate 125 and the inner wall of the first piezoelectric tube 131 at the contact point. Therefore, the spring plate 125 makes the slide rod 121 more securely nested in the free end of the first piezoelectric tube 131, and ensures that the slide rod 121 is as consistent as possible with the length direction of the free end of the first piezoelectric tube 131 during the extension and retraction of the free end of the first piezoelectric tube 131 along its own length, so as to avoid skewing.

[0043] It's also important to explain here that during the scanning of the sample surface, when the free end of the first piezoelectric tube 131 swings in the XY plane, the slide rod 121 will also swing in the XY plane along with the free end of the first piezoelectric tube 131. This inevitably leads to axial tilting of the slide rod 121 relative to the fixed end of the first piezoelectric tube 131. However, we want the tilting degree of the slide rod 121 to be the same as that of the free end of the first piezoelectric tube 131, because only in this way can we achieve precise control of the sample stage 122 on the slide rod 121 by controlling the free end of the first piezoelectric tube 131. If the tilting degree of the slide rod 121 is uncontrolled during the swinging of the free end of the first piezoelectric tube 131 in the XY plane, the sample safety and scanning accuracy during the scanning imaging process cannot be guaranteed.

[0044] Therefore, the setting of the spring plate 125 will further apply radial pressure along the free end of the first piezoelectric tube 131 to the slide bar 121, ensuring that the tilt of the slide bar 121 is the same as that of the free end of the first piezoelectric tube 131, thus better ensuring the sample safety and scanning accuracy during the scanning imaging process.

[0045] In this embodiment, there may be multiple spring sheets 125.

[0046] In this embodiment, the first piezoelectric tube 131 and the second piezoelectric tube 132, which are nested and coaxially arranged, constitute the drive unit 13. This unit serves two purposes: firstly, it secures the components in the scanning imaging unit 12, enabling the microscope body to possess the functions described above; secondly, it confines all components within the microscope body to the second piezoelectric tube 132, resulting in a compact and small microscope body 1 that can be directly embedded in a universal dry magnet to achieve 360° continuous rotation, offering strong compatibility. Therefore, technicians no longer need to worry about selecting the magnet cavity and can directly use a universal dry magnet, which also reduces the construction cost of the rotating microscope in this embodiment.

[0047] In this embodiment of the microscope body, the probe 124 and the sample stage 122 are arranged opposite to each other, and the probe 124 and the sample stage 122 are located on two different piezoelectric tubes, and their positions are controlled only by the corresponding piezoelectric tubes. That is, the sample stage 122 can be moved closer to or away from the probe 124 by individually controlling the extension and retraction of the free end of the first piezoelectric tube 131; the probe 124 can be moved closer to or away from the sample stage 122 by individually controlling the extension and retraction of the free end of the second piezoelectric tube 132; or the probe 124 can be moved closer to or away from the sample stage 122 by simultaneously controlling the relative distance between the free ends of the first and second piezoelectric tubes 131 and 132. Therefore, this embodiment offers high flexibility in the probe insertion and retraction methods within the microscope body.

[0048] In this embodiment of the microscope body, during the scanning imaging process, the degree of offset of the free end of the first piezoelectric tube 131 or the free end of the second piezoelectric tube 132 in the XY plane can be controlled independently to control the position of the probe 124 for scanning imaging on the sample. For samples with a large area, this embodiment can also simultaneously control the free ends of the first piezoelectric tube 131 and the second piezoelectric tube 132 to offset in opposite directions to quickly achieve full coverage scanning of large-area samples (for example, the free end of the first piezoelectric tube 131 is offset to the left, while the free end of the second piezoelectric tube 132 is offset to the right, so that the scanning coverage of the probe 124 is much larger than the case where only the free end of the first piezoelectric tube 131 or only the free end of the second piezoelectric tube 132 is offset). Therefore, the microscope body of this embodiment can achieve large-area scanning imaging of samples, and the scanning imaging method is highly flexible.

[0049] The microscope in this embodiment, while having a compact and small structure, also provides a sufficiently large insertion and retraction stroke for the probe 124; it can also achieve large-area scanning imaging of the sample within the second piezoelectric tube 132, which is not available in existing scanning probe microscopes.

[0050] In this embodiment of the microscope body, the two piezoelectric tubes included in the drive unit 13 are coaxially nested, and their corresponding fixed ends are both on the first base 11. Therefore, when mechanical vibrations inside the microscope body are transmitted to these two piezoelectric tubes, the degree, frequency, type, and direction of interference (type refers to, for example, interference is mechanical vibration, and direction refers to, for example, the direction of movement of this type of interference) are the same. This makes the relative interference between the free ends of the first piezoelectric tube 131 and the second piezoelectric tube 132 very small (or even zero). Therefore, this embodiment of the microscope body can effectively suppress the common-mode noise of the drive unit 13, reduce the thermal drift rate, improve the thermal stability of the drive unit 13, and further ensure the stability, accuracy, and safety of the probe 124 and the sample stage 122 during probe insertion, scanning imaging, and probe retraction.

[0051] The rotation module 2 includes a rotation drive device 21 and a clamping member 22. The clamping member 22 clamps the mirror body 1, and the rotation drive device 21 drives the clamping member 22 to rotate, so as to rotate the mirror body 1 together.

[0052] The rotating module 2 also includes a pin ring 23 disposed on the mirror body 1 and fixedly inserted between it and the clamping member 22. Technicians can adjust the energization of the pins on the pin ring 23 (e.g., changing the voltage) according to experimental requirements. The presence of the pin ring 23 allows the mirror body 1 to be connected to or detached from the clamping member 22 via insertion and removal, and ensures a secure fixation on the clamping member 22, while also providing good conductivity at the insertion point.

[0053] like Figure 4 As shown, it is from Figure 1 A schematic diagram of the rotary drive device viewed from left to right. The rotary drive device 21 includes a third piezoelectric tube 211, a C-shaped spring plate 212, a bearing 213, a rotor 214, and a second base 215. The third piezoelectric tube 211 includes a fixed end and a free end. The fixed end of the third piezoelectric tube 211 is fixedly mounted on the second base 215, and the free end of the third piezoelectric tube 211 is fixedly connected to the first end of the C-shaped spring plate 212. The second end of the C-shaped spring plate 212 is in elastic compression contact with the bearing 213 at all times. The rotor 214 is nested in the center of the bearing 213 and fixedly connected to the clamping member 22.

[0054] When the third piezoelectric tube 211 is in its initial state, the second end of the C-shaped spring plate 212 is in elastic compression contact with the top of the bearing 213, and the bearing 213 and the C-shaped spring plate 212 are relatively stationary; the second pressure F2 applied by the second end of the C-shaped spring plate 212 to the bearing 213 is vertically downward. The initial state of the third piezoelectric tube 211 means that the free end of the third piezoelectric tube 211 has no X-axis and Y-axis displacement, and is contracted to its shortest length on the Z-axis.

[0055] The free end of the third piezoelectric tube 211 undergoes deformation motion within the XYZ three-dimensional quadrant.

[0056] The instant the free end of the third piezoelectric tube 211 begins to move from its initial state, the first pressure F1 directly applied by the free end of the third piezoelectric tube 211 to the first end of the C-shaped spring plate 212 changes. For example, the direction of the first pressure F1 changes from vertically downward to downward to the left, causing the C-shaped spring plate 212 to tend to move downward to the left. When the first pressure F1 is transmitted to the bearing 213, it manifests as a change in the second pressure F2 applied by the second end of the C-shaped spring plate 212 to the bearing 213, and the degree and direction of the change of the second pressure F2 are the same as the trend of the change of the first pressure F1. Decomposing the second pressure F2 into a third thrust F3 in the XY plane and a fourth pressure F4 in the Z-axis direction, it can be clearly seen that the third thrust F3 is tangential to the bearing 213, and the fourth pressure F4 is radial to the bearing 213. Therefore, the bearing 213 also exhibits the same movement trend as the C-shaped spring plate 212 (e.g., a tendency to move downward to the left).

[0057] In summary, the deformation motion of the free end of the third piezoelectric tube 211 is indirectly transmitted to the bearing 213 through the C-shaped spring plate 212, generating a tangential thrust on the bearing 213, thereby controlling the direction and rotation angle of the bearing 213. The bearing 213 drives the clamping member 22 to rotate through the synchronously rotating rotor 214, thereby driving the mirror body 1 to rotate together.

[0058] It needs to be explained here that although there is a frictional force opposite to the direction of the third thrust F3 because the second end of the C-type spring plate 212 and the bearing 213 are always in elastic compression contact, this frictional force is very small when the second end of the C-type spring plate 212 and the bearing 213 maintain the same tendency of movement.

[0059] Optionally, a Hall sensor is fixedly installed on the rotor 214, and the rotation angle is calibrated based on the resistance reading of the Hall sensor. Technicians can continuously adjust the angle of the bearing 213 based on the resistance reading of the Hall sensor, thereby achieving continuous adjustment of the rotation angle of the mirror body 1. This is convenient to operate and avoids the risks of manual operation under strong magnetic fields.

[0060] Compared to the discontinuous angle control achieved by mechanical gears in the prior art, the rotation module 2 in this embodiment can achieve continuous control of the rotation angle of the mirror body 1, meeting the flexibility requirements of technicians for conducting experiments with scanning probe microscopes in high-intensity magnetic fields.

[0061] In this embodiment, the rotation module 2 indirectly drives the bearing 213 to rotate tangentially via the C-shaped spring plate 212 through the third piezoelectric tube 211. Because the entire indirect driving process is a flexible transmission, the amplitude of disturbances such as mechanical vibrations, when transmitted to the C-shaped spring plate 212, will be significantly weakened or even eliminated due to the deformation of the C-shaped spring plate 212 and the friction between the second end of the C-shaped spring plate 212 and the contact surface between the bearing 213 (the kinetic energy of the mechanical vibration is converted into the elastic potential energy of the spring plate and the heat energy generated by friction). That is, the rotation module 2 of this embodiment can stably and accurately continuously control the rotation angle of the mirror body 1.

[0062] The rotating microscope in this embodiment is a scanning probe microscope. The rotating module 2 drives the microscope body 1, creating a full-angle magnetic field environment for scanning and imaging the sample within the microscope body. It is compatible with low-temperature experiments and can operate in strong magnetic fields at all angles. This meets the requirements of scanning probe microscopes for experiments in high-intensity magnetic fields, enabling high-quality and stable scanning imaging of samples within such environments, thus improving experimental efficiency.

[0063] Example 2 This embodiment provides a rotating microscope with coaxial piezoelectric tube counter-scanning, which differs from Embodiment 1 in that the scanning imaging unit 12 and the driving unit 13 in the microscope body 1 are as follows: Figure 2 As shown, the following only describes in detail the technical features and effects that differ from Embodiment 1; other identical parts will not be repeated: The driving unit 13 includes a first piezoelectric tube 131 and a second piezoelectric tube 132 nested together; the scanning imaging unit 12 also includes a sample stage 122. Both the first piezoelectric tube 131 and the second piezoelectric tube 132 have a fixed end and a free end. The fixed ends of both the first piezoelectric tube 131 and the second piezoelectric tube 132 are fixedly mounted on the first base 11. The sample stage 122 is disposed at the free end of the first piezoelectric tube 131. A probe holder 123 is disposed on the free end of the second piezoelectric tube 132, and a probe 124 is fixedly mounted on the probe holder 123 with its tip facing the sample stage 122. The sample is fixed on the side of the sample stage 122 facing the probe 124.

[0064] In this example, there is no option to "or swap the positions of probe 124 and sample stage 122".

[0065] This example does not require the length of the second piezoelectric tube 132 to always exceed that of the first piezoelectric tube 131, because the probe holder 123 itself has a certain height. Therefore, the mirror body 1 structure in this embodiment is suitable for cases where the length difference ΔL is less than the first length difference threshold D1, where ΔL = L2 - L1, L1 represents the shortest straight-line distance between the sample stage 122 and the first base 11, at which time the free end of the first piezoelectric tube 131 is in its maximum contracted state; L2 represents the shortest straight-line distance between the tip of the probe 124 and the first base 11, at which time the free end of the second piezoelectric tube 132 is in its maximum extended state.

[0066] Regardless of how stable the insertion and withdrawal processes are, when ΔL is too small (i.e., less than the first length difference threshold D1), even a slight vibration transmitted to the probe 124 or the sample stage 122 may cause the needle tip to collide with the sample surface, which is detrimental to the safety of the needle tip and the sample surface during insertion and withdrawal. Therefore, this embodiment adds a sample stage 122 to the free end of the second piezoelectric tube 132 to increase L2 and ΔL, thereby further improving the safety of the needle tip and the sample surface during insertion and withdrawal.

[0067] Example 3 The present invention also provides a scanning imaging method using a rotating microscope with coaxial piezoelectric tubes scanning in opposite directions as described in Example 1 or Example 2, comprising the following steps: S1, Needle insertion: When the drive unit 13 receives the needle insertion signal from the signal acquisition module, it drives the probe 124 in the scanning imaging unit 12 to continuously approach the sample stage 122 until it receives the needle insertion end signal from the signal acquisition module.

[0068] The signal acquisition module will send a needle insertion end signal if any of the following occurs: ① The signal acquisition module acquires the tunneling current between the probe and the sample; ②The signal acquisition module detected a sudden change in the atomic force between the probe and the sample.

[0069] Case ① and Case ② represent two different scanning imaging principles for the sample surface. The microscope in this embodiment can use either principle to scan and image the sample surface.

[0070] S2, Single Scan Imaging: When the signal acquisition module sends a scanning signal, the drive unit 13 drives the probe 124 to move in the XY plane relative to the sample stage 122. The probe 124 performs a single scan imaging of the sample surface to obtain a sample morphology image. After the scanning imaging is completed, the probe retraction process begins.

[0071] S3, Needle retraction: After receiving the needle retraction signal from the signal acquisition module, the drive unit 13 drives the probe 124 in the scanning imaging unit 12 to move away from the sample stage 122 continuously; the needle retraction process ends when the free end of the first piezoelectric tube 131 in the drive unit 13 retracts to its minimum length and / or the free end of the second piezoelectric tube 132 in the drive unit 13 extends to its maximum length.

[0072] In the drive unit 13 of S1: Action 1: The free end of the first piezoelectric tube 131 continuously extends towards the free end of the second piezoelectric tube 132; Action 2: The free end of the second piezoelectric tube 132 continuously retracts towards the fixed end of the first piezoelectric tube 131; At least one of Action 1 and Action 2 is adopted, so that the probe 124 continuously approaches the sample stage 122.

[0073] In the drive unit 13 of S2: Action 3: The free end of the first piezoelectric tube 131 moves in the XY plane; Action 4: The free end of the second piezoelectric tube 132 moves in the XY plane; At least one of Action 3 and Action 4 is taken so that the probe 124 scans and images the sample surface.

[0074] Optionally, after S2 and before S3, the following may be included: the driving unit 13 drives the probe 124 to a constant height and then performs a secondary scanning imaging along the sample morphology trajectory to draw a sample magnetic field map.

[0075] When plotting the sample's magnetic field map, because the short-range atomic forces (van der Waals forces) have weakened considerably after the probe tip 124 is raised to a constant height, the long-range static magnetic force becomes dominant. An attractive or repulsive static magnetic force is generated between the magnetic tip and the sample's magnetic domains. This force causes a change in the resonant frequency or amplitude of the free end of the piezoelectric tube connected to probe 124. By detecting this change, the sample surface magnetic field map can be plotted.

[0076] In the drive unit 13 of S3: Action 5: The free end of the first piezoelectric tube 131 continuously retracts towards the fixed end of the second piezoelectric tube 132; Action 6: The free end of the second piezoelectric tube 132 continuously extends away from the free end of the first piezoelectric tube 131; At least one of Action 3 and Action 4 is adopted so that the probe 124 continuously moves away from the sample stage 122.

[0077] Optionally, after S1 and before S2, there is also S1´:S1´, which creates a full-angle magnetic field environment: the rotation module 2 drives the mirror 1 to rotate in the magnet cavity.

[0078] In S1´, specifically: the free end of the third piezoelectric tube 211 extends and swings to squeeze the C-shaped spring plate 212. The C-shaped spring plate 212 drives the bearing 213 to rotate through the squeezing contact. The rotor 214, which rotates synchronously inside the bearing 213, drives the fixedly connected clamping member 22 to rotate, so as to drive the mirror body 1 on the clamping member 22 to rotate in the magnet cavity.

[0079] The scanning imaging method of this embodiment can create a full-angle magnetic field environment and perform high-quality and stable scanning imaging of the sample in the full-angle magnetic field environment; it also greatly reduces interference inside the microscope lens, enhances the safety when the needle tip approaches and moves away from the sample, and improves the quality and stability of the imaging, thereby increasing experimental efficiency.

[0080] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A coaxial piezoelectric tube opposite scanning rotary microscope, comprising a rotary mirror body, a magnet cavity, a signal acquisition module and a computer, the rotary mirror body and the magnet cavity are electrically connected with the signal acquisition module, and the signal acquisition module and the computer are electrically connected, characterized in that: The magnet cavity generates a magnetic field environment; the rotating mirror body comprises a mirror body (1) and a rotating module (2) arranged in the magnet cavity, the mirror body (1) is fixed on the rotating module (2), and the rotating module (2) can drive the mirror body (1) to rotate; the mirror body (1) comprises a scanning imaging unit (12) and a driving unit (13), the scanning imaging unit (12) comprises a sample table (122) and a probe (124), the driving unit (13) comprises two piezoelectric tubes, the sample table (122) and the probe (124) are respectively fixedly arranged at free ends of the two piezoelectric tubes; the free ends of the two piezoelectric tubes drive the probe (124) to perform needle insertion, needle retraction or scanning imaging relative to the sample table (122).

2. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 1, characterized in that: The mirror body (1) further comprises a first base (11), the two piezoelectric tubes are respectively a first piezoelectric tube (131) and a second piezoelectric tube (132); the fixed end of the first piezoelectric tube (131) and the second piezoelectric tube (132) are nested, and the fixed end of the first piezoelectric tube (131) and the fixed end of the second piezoelectric tube (132) are both fixed on the first base (11).

3. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 2, characterized in that: The length of the second piezoelectric tube (132) is always longer than that of the first piezoelectric tube (131), the free end of the first piezoelectric tube (131) is in the second piezoelectric tube (132), the probe (124) is arranged at the free end of the second piezoelectric tube (132) and the needle tip faces the sample table (122), the sample table (122) is arranged at the free end of the first piezoelectric tube (131), and the sample faces the probe (124) and is fixed on the sample table (122).

4. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 2, characterized in that: The scanning imaging unit (12) further comprises a probe support (123) fixedly arranged at the free end of the second piezoelectric tube (132); the probe (124) is fixedly arranged on the probe support (123) and the needle tip faces the sample table (122); the sample table (122) is arranged at the free end of the first piezoelectric tube (131); and the sample faces the probe (124) and is fixed on the sample table (122).

5. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 3 or 4, characterized in that: The scanning imaging unit (12) further comprises a slide rod (121) nested in the free end of the first piezoelectric tube (131); one end of the slide rod (121) is located inside the free end of the first piezoelectric tube (131), the other end of the slide rod (121) is located outside the first piezoelectric tube (131) and faces the probe (124); and the outer wall of the slide rod (121) is in extrusion contact with the inner wall of the first piezoelectric tube (131).

6. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 5, characterized in that: The scanning imaging unit (12) further comprises a spring sheet (125) fixedly arranged on the outer wall of the slide rod (121) and in extrusion contact with the inner wall of the first piezoelectric tube (131).

7. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 1, characterized in that: The rotating module (2) comprises a rotating driving device (21) and a clamping piece (22), the rotating driving device (21) comprises a third piezoelectric tube (211), a C-shaped spring sheet (212), a bearing (213), a rotor (214) and a second base (215), the third piezoelectric tube (211) comprises a fixed end and a free end, the fixed end of the third piezoelectric tube (211) is fixed on the second base (215), and the free end of the third piezoelectric tube (211) is fixedly connected with a first end of the C-shaped spring sheet (212); a second end of the C-shaped spring sheet (212) is always elastically extruded with the bearing (213); the rotor (214) is nested in the center of the bearing (213) and is fixedly connected with the clamping piece (22); and the clamping piece (22) clamps the mirror body (1).

8. A rotation microscope with on-axis piezoelectric tube counter-scanning according to claim 7, characterized in that: The rotating module (2) further comprises a pin ring (23) which is arranged on the mirror body (1) and is fixedly connected between the clamping piece (22); a Hall sensor is fixedly arranged on the rotor (214), and the bearing (213) is continuously regulated in angle after the rotation angle is calibrated according to the resistance indication of the Hall sensor.

9. A scanning imaging method applied to a rotation microscope with a coaxial piezoelectric tube counter-scanning according to any one of claims 1-8, characterized in that, The method comprises the following steps: S1, needle insertion: when two piezoelectric tubes in the driving unit (13) receive a needle insertion signal sent by the signal acquisition module, the probe (124) is continuously close to the sample stage (122), until a needle insertion end signal sent by the signal acquisition module is received; When any of the following conditions occurs, the signal acquisition module sends a needle insertion end signal: ① the signal acquisition module collects the tunneling current between the probe and the sample; ② the signal acquisition module collects the atomic force mutation between the probe and the sample; S2, one-time scanning imaging: when the signal acquisition module sends a scanning signal, the two piezoelectric tubes in the driving unit (13) drive the probe (124) to move relative to the XY plane of the sample stage (122), the probe (124) performs one-time scanning imaging on the sample surface to obtain a sample topography map; after the scanning imaging is completed, the needle withdrawal process is entered; S3, needle withdrawal: after the two piezoelectric tubes in the driving unit (13) receive a needle withdrawal signal sent by the signal acquisition module, the probe (124) is continuously away from the sample stage (122); when the free end of the piezoelectric tube in the driving unit (13) retracts to the minimum length or extends to the maximum length, the needle withdrawal process is completed.

10. The method of claim 9, wherein, After S1 and before S2, S1' is further included: S1', manufacturing a full-angle magnetic field environment: the rotating module (2) drives the mirror body (1) to rotate in the magnet cavity.

Images