A scanning tunneling microscope body with mechanical series connection of tube-shaped approach and imaging units

Abstract

The present invention discloses a mechanical series scanning tunnel microscope body of a tube-type approach and imaging unit, comprising a base, a slide bar, a sleeve and a spring sheet, characterized in that it also comprises a first piezoelectric tube, a second piezoelectric tube and a probe bracket, wherein one end of the first piezoelectric tube is fixed to the base, and the other end is fixed in series with the second piezoelectric tube along the axial direction, the sleeve is coaxially fixed to the deformed free end of the second piezoelectric tube, the spring sheet applies radial pressure along the sleeve to clamp the slide bar to the inner wall of the guide rail, the sliding direction of the slide bar is along the axial direction of the sleeve, the probe bracket is coaxially arranged with the second piezoelectric tube, and one end is fixed at the position where the first piezoelectric tube and the second piezoelectric tube are connected in series. The radial and axial structures of the mirror body of the invention are highly compact, the second piezoelectric tube is also used for approaching to achieve a low starting voltage of the needle-like approach step, and at the same time ensures the high rigidity of the scanning unit, the main body is made of insulating material, and the cross section of the structure has no conductive circuit, which is particularly suitable for extreme physical conditions such as extremely low temperature, strong / fast changing magnetic field, and strong vibration.

Description

Technical Field

[0001] The invention discloses a tube-shaped approaching and imaging unit mechanical series-connected scanning tunnel microscope body, which belongs to the technical field of scanning probe microscopes, and in particular relates to a scanning tunnel microscope. Background Art

[0002] Scanning tunneling microscopy (STM) can provide information about the electronic state distribution and band structure of the material surface at the atomic scale. It is a powerful characterization method in the fields of condensed matter physics and materials (Rev. Mod. Phys. 79 (2007) 353-419). The most core component of STM is the mirror, which directly determines the resolution performance of the microscopic characterization of the STM system, and also determines the complexity of the system that can be integrated with the STM. The most common STM system integration conditions include room temperature ultra-high vacuum, solution, and low temperature and strong magnetic field versions. Among them, the low temperature and strong magnetic field version is the most difficult, but it is the version with the most important application in condensed matter physics, because the large temperature range and magnetic field range can effectively adjust the charge order, ferromagnetic and antiferromagnetic order of the strongly correlated electronic system to explore its mechanism.

[0003] At present, conventional low-temperature and high-magnetic-field versions of STM mostly work in quiet liquid helium superconducting magnets (usually less than 23T) to obtain magnetic field regulation, and to obtain low-temperature conditions in conjunction with different types of refrigerators. With the demand of researchers for more extreme test conditions, the STM mirror body suitable for new extreme conditions needs to be designed according to local conditions. For example, a water-cooled magnet or even a hybrid magnet is used to obtain a magnetic field of more than 40T, but the room-temperature aperture provided by the magnet does not exceed 50 mm. In order to obtain low-temperature test conditions, a cryostat needs to be implanted therein, which further reduces the available space in the sample chamber. In addition, the vibration intensity of water-cooled magnets (including hybrid magnets) is large, and the magnetic field ripple is much higher than that of traditional superconducting magnets, which increases the design difficulty of the STM. At present, only two attempts have been reported internationally (Nano Research 8, 3898 (2015); Rev. Sci. Instrum. 88, 093706 (2017)), but both have shortcomings: for example, although the work of Meng et al. achieved atomic-level imaging at 27 T, it did not introduce cryogenic conditions; although the work of Tao et al. provided cryogenic test conditions, the atomic-level imaging was lost when the magnetic field was raised to about 5 T. Therefore, a new STM mirror that is suitable for home space and can effectively resist magnetic field ripple interference is the fundamental solution to this problem.

[0004] The invention patent "Multi-zone driven inertial piezoelectric motor device, scanning probe microscope and control method" (patent number: 201410209747.8) proposes a radial space-compatible inertial piezoelectric motor device and scanning probe microscope. In order to ensure the step stability of the motor under low temperature conditions, the length of the piezoelectric body group is required to be large enough. The advantage of this design is that it can achieve large-range scanning of tens of microns, but because the probe sample loop is not compact enough, it is difficult to achieve atomic-level imaging.

[0005] The present invention proposes a mechanical series-connected scanning tunnel microscope body of a tubular approach and imaging unit, which can realize a narrow radial dimension and compact axial dimension of the body, and can realize a metal-free design, and is suitable for conditions of rapid magnetic field changes. Using the scanning tunnel microscope made by the structure of the present invention, the inventor successfully achieved 30T atomic resolution images in a hybrid magnet (composed of an outer superconducting magnet and an inner water-cooled magnet, which is a device that can currently obtain the highest steady-state magnetic field strength), which is the highest magnetic field record for atomic resolution imaging, and is also the world's first scanning tunnel microscope that successfully works in a hybrid magnet. Summary of the invention

[0006] The purpose of the present invention is to further optimize the compactness and strong magnetic field resistance of the existing scanning probe microscope body, and to propose a tubular approach and imaging unit mechanical series scanning tunneling microscope body.

[0007] The technical solution of the present invention to achieve the above object is:

[0008] The tube-type approximation and imaging unit mechanical series scanning tunnel microscope body comprises a base, a sliding rod, a sleeve and a spring sheet, and is characterized in that it also comprises a first piezoelectric tube, a second piezoelectric tube and a probe bracket, wherein one end of the first piezoelectric tube is fixed to the base, and the other end is a deformation free end, one end of the second piezoelectric tube is coaxially fixed with the free end of the first piezoelectric tube, and the other end of the second piezoelectric tube is a deformation free end, and the second piezoelectric tube is a four-quadrant split XYZ piezoelectric tube, and the sleeve is coaxially fixed to the deformation free end of the second piezoelectric tube, and the spring sheet applies radial pressure along the sleeve to elastically clamp the sliding rod to the inner wall of the sleeve, and the sliding direction of the sliding rod is along the axial direction of the sleeve, and the probe bracket is coaxially arranged with the second piezoelectric tube, one end of which is fixed to the deformation free end of the first piezoelectric tube, and the other end faces the forward direction of the sliding rod.

[0009] The tube-type approach and imaging unit mechanical series scanning tunnel microscope body is characterized in that the first piezoelectric tube is an XYZ piezoelectric tube divided into four quadrants along the axial direction.

[0010] The tube-type approach and imaging unit mechanical series scanning tunneling microscope body is characterized in that the first piezoelectric tube and the second piezoelectric tube are arranged in one piece.

[0011] The tube-type approach and imaging unit mechanical series scanning tunnel microscope body is characterized by: an independent probe bracket is added, the independent probe bracket is coaxially arranged with the deformation direction of the first piezoelectric tube, one end of the independent probe bracket is fixed to the base, and the other end faces the forward direction of the slide rod.

[0012] The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body is characterized in that the base or sleeve or sliding rod or probe bracket or independent probe bracket is made of insulating material.

[0013] The tube-shaped approach and imaging unit mechanical series scanning tunnel microscope body is characterized in that the base or sleeve or sliding rod or probe bracket or independent probe bracket is made of sapphire or zirconium oxide material.

[0014] The present invention discloses a tube-type approach and imaging unit mechanical series scanning tunnel microscope body, and its working principle is: one end of the probe bracket is fixed to the deformable free end of the first piezoelectric tube, and the other end faces the forward direction of the sliding rod and is provided with a probe pointing to the sliding rod, and a sample is arranged on the end surface of the sliding rod pointing to the probe, so that the probe sample loop thus formed is compact, and at the same time, the second piezoelectric tube in the loop can also be used to jointly generate Z-axial deformation together with the first piezoelectric tube, thereby driving the sliding rod to achieve efficient stepping.

[0015] The described tubular approach and imaging unit mechanical series scanning tunnel microscope body is characterized in that: the outer electrode of the first piezoelectric tube is divided into four quadrants along the axial direction, and the base, sleeve, sliding rod, probe bracket and independent probe bracket are all made of insulating material. At the same time, the first piezoelectric tube and the second piezoelectric tube are both divided into four quadrants by the outer electrode to achieve a cross-section without a conductive loop. In summary, it can effectively avoid the magnetic field ripple to generate eddy current in the mirror body, thereby avoiding the heating effect of the mirror body caused by magnetic field ripple or rapid changes in the magnetic field and the introduction of vibration.

[0016] The tubular approach and imaging unit mechanical series scanning tunneling microscope body can perform other scanning probe microscopes with resolution requirements, such as atomic force microscope, by replacing the probe.

[0017] The tube-type approach and imaging unit mechanical series scanning tunnel microscope body is characterized by: adding an independent probe bracket, the independent probe bracket is coaxially arranged with the deformation direction of the first piezoelectric tube, one end of the independent probe bracket is fixed to the base, and the other end points to the end face of the slide bar away from the base and an additional probe is added, and the auxiliary probe points to the slide bar. Since the fixed end of the independent probe bracket is fixed to the base, a larger range of scanning can be performed, which is particularly suitable for scanning force microscopes with non-atomic resolution requirements, such as magnetic force microscopes (mainly used to observe magnetic domain structures, which are often at the micron level). The dual probe frame design can realize the combined microscopic imaging function of the scanning tunnel microscope and the scanning force microscope.

[0018] According to the above principle, the present invention has the following excellent performance (therefore achieving the purpose of the present invention):

[0019] (1) It achieves compactness in the axial and radial directions, strong rigidity, and vibration resistance, and is suitable for ultra-narrow sample spaces.

[0020] (2) The structure is simple, and the main body can be made of all insulating materials. There is no conductive loop in the cross section, which is suitable for harsh test conditions with rapid changes in the magnetic field.

[0021] (3) The second piezoelectric tube contributes to the coarse approximation, achieving a lower starting voltage and a larger motor thrust within a limited axial space, while taking into account the high rigidity of the probe and sample tunnel junction circuit, which is particularly suitable for use in harsh testing conditions such as strong vibration, low temperature, and strong magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of the structure of a scanning tunnel microscope body with a tube-shaped approach and imaging unit mechanically connected in series.

[0023] Figure 2 The present invention is a schematic diagram of the structure of a scanning tunnel microscope body in which a tube-type approximation and imaging unit is mechanically connected in series and the first piezoelectric tube is divided into four quadrants.

[0024] Figure 3 This is a schematic diagram of the scanning tunnel microscope structure of the present invention, in which the tube-type approximation and imaging units are mechanically connected in series and the first piezoelectric tube and the second piezoelectric tube are integrated.

[0025] Figure 4 It is a schematic diagram of the double-probe frame structure of a mechanical series-connected scanning tunneling microscope body of a tube-shaped approach and imaging unit of the present invention.

[0026] Numbers in the figure: 1 base, 2A first piezoelectric tube, 2B four-quadrant divided first piezoelectric tube, 2C integrated first piezoelectric tube, 3 second piezoelectric tube, 4 sliding rod, 5 sleeve, 6 spring sheet, 7 probe bracket, 8A probe bracket and first piezoelectric tube fixing point, 8B sleeve and scanning piezoelectric tube fixing point, 9 sample stage, 10A probe, 10B auxiliary probe, 11 independent probe bracket.

[0027] The present invention is further described below through specific implementation modes and structural drawings. DETAILED DESCRIPTION

[0028] Example 1: See Figure 1 A tube-type approach and imaging unit mechanical series scanning tunnel microscope body, comprising a base 1, a slide bar 4, a sleeve 5 and a spring sheet 6, characterized in that it also includes a first piezoelectric tube 2A, a second piezoelectric tube 3 and a probe bracket 7, one end of the first piezoelectric tube 2A is fixed to the base 1, and the other end is a deformation free end, one end of the second piezoelectric tube 3 is coaxially fixed with the free end of the first piezoelectric tube 2A, the other end of the second piezoelectric tube 3 is a deformation free end, the second piezoelectric tube 3 is a four-quadrant split piezoelectric tube, the sleeve 5 is coaxially fixed to the deformation free end of the second piezoelectric tube 3, the spring sheet 6 applies radial pressure along the sleeve 5 to elastically clamp the slide bar 4 to the inner wall of the sleeve 5, and the slide bar 4 slides The moving direction is along the axial direction of the sleeve 5, and the probe bracket 7 is coaxially arranged with the second piezoelectric tube 3, one end of which is fixed at the deformed free end 8A of the first piezoelectric tube 2A, and the other end points to the forward direction of the slide bar 4 and a probe 10A pointing to the slide bar 4 is additionally provided, and a sample stage 9 is additionally provided on the end face of the slide bar 4 pointing to the probe 10A. The first piezoelectric tube 2A has a large diameter and a large thrust of the piezoelectric body, which helps to increase the thrust of the slide bar 4 sliding along the inertia of the sleeve 5. Since the root of the probe bracket 7 is fixed at 8A of the deformed free end of the first piezoelectric tube, a small range but high-precision scanning is completely derived from the compact second piezoelectric tube 3, so that large thrust, high-efficiency stepping and high-precision, atomic-resolution imaging scanning can be taken into account.

[0029] Example 2: See Figure 2 A tube-type approach and imaging unit mechanical series scanning tunnel microscope body, characterized in that: the outer electrode of the first piezoelectric tube 2A is an XYZ piezoelectric tube 2B divided into four quadrants along the axial direction, the second piezoelectric tube 3 and the first piezoelectric tube 2B also have an outer electrode divided into four quadrants, the outer electrodes can be short-circuited axially one by one and share electrodes, thereby effectively reducing control signals and control lines.

[0030] Example 3: See Figure 3 A tube-type approach and imaging unit mechanical series scanning tunneling microscope body, characterized in that: the first piezoelectric tube 2B and the second piezoelectric tube 3 are integrated into an integrated first piezoelectric tube 2C, simplifying the body structure.

[0031] Embodiment 4: A tube-type approach and imaging unit mechanical series scanning tunnel microscope body, characterized in that: an independent probe holder 11 is added, the independent probe holder 11 is coaxially arranged with the deformation direction of the integrated first piezoelectric tube 2C, one end of the independent probe holder 11 is fixed to the base 1, and the other end points to the forward direction of the slide bar 4 and an auxiliary probe 10B is added, the auxiliary probe 10B points to the slide bar 4, the added independent probe holder 11 has its root located on the base, so the integrated first piezoelectric tube 2C can be completely used for probe scanning to achieve large-scale search or imaging, and the compact circuit formed by the probe holder 7 can still perform high-precision atomic resolution imaging.

[0032] Embodiment 5: A tubular approach and imaging unit mechanical series scanning tunneling microscope body, characterized in that: the base 1 or sleeve 5 or slide rod 4 or probe holder 7 or independent probe holder 11 is made of insulating material, so that the main body of the scanning tunneling microscope body is made of non-metallic material, which is particularly suitable for use in harsh testing conditions of high-intensity magnetic field, large magnetic field ripple and fast-changing magnetic field.

[0033] Embodiment 6: A tube-type approach and imaging unit mechanical series scanning tunnel microscope body, characterized in that: the base 1 or the sleeve 5 or the sliding rod 4 or the probe holder 7 or the independent probe holder 11 is made of sapphire or zirconium oxide material.

Claims

1. A tube-shaped approach and imaging unit mechanical series scanning tunnel microscope body, comprising a base, a slide rod, a sleeve and a spring sheet, characterized in that It also includes a first piezoelectric tube, a second piezoelectric tube and a probe bracket, one end of the first piezoelectric tube is fixed to the base, and the other end is a deformation free end, one end of the second piezoelectric tube is coaxially fixed to the free end of the first piezoelectric tube, the other end of the second piezoelectric tube is a deformation free end, the second piezoelectric tube is a four-quadrant split XYZ piezoelectric tube, the sleeve is coaxially fixed to the deformation free end of the second piezoelectric tube, the spring sheet applies radial pressure along the sleeve to elastically clamp the sliding rod to the inner wall of the sleeve, the sliding direction of the sliding rod is along the axial direction of the sleeve, the probe bracket is coaxially arranged with the second piezoelectric tube, one end of the probe bracket is fixed to the deformation free end of the first piezoelectric tube, and the other end faces the forward direction of the sliding rod.

2. The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body according to claim 1, characterized in that: The first piezoelectric tube is an XYZ piezoelectric tube divided into four quadrants along the axial direction.

3. The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body according to claim 2, characterized in that: The first piezoelectric tube and the second piezoelectric tube are integrally arranged.

4. The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body according to claim 2, characterized in that: An independent probe bracket is additionally provided, and the independent probe bracket is coaxially arranged with the deformation direction of the first piezoelectric tube, one end of the independent probe bracket is fixed to the base, and the other end faces the forward direction of the sliding rod.

5. The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body according to claim 2, characterized in that: The base, sleeve, slide rod, probe support or independent probe support is made of insulating material.

6. The tube-shaped approach and imaging unit mechanical series scanning tunneling microscope body according to claim 2, characterized in that: The base, sleeve, slide rod, probe support or independent probe support is made of sapphire or zirconium oxide.

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