Transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth
Technical field
The present invention relates to scanning probe microscopy mirror body; Be particularly related to a kind of fully low pressure low temperature drift of transposition in length and breadth scanning probe microscopy mirror body; Be specifically a kind of be arranged to the probe and the adjusting direction of sample interval vertical with the piezo tube axis direction to improve the range of adjustment of probe-sample interval; Make under all using, also can realize to use in the past and slightly approach, carefully approach and, and have the very scanning probe microscopy mirror body of high thermal stability the function of macrorelief surface imaging greater than what the high voltage of 18V could be realized less than the low voltage condition of 18V.
Background technology
Probe-the sample of existing scanning probe microscopy (SPM) slightly approaches general use piezo-electric motor, stepper motor or screw and regulates three kinds of technology; Their step pitch is big, location repeatability is undesirable, slightly approaching after, must use the high voltage that is higher than 18V carefully to approach (fine tuning) and control piezo tube and locate and could probe-sample interval reliably, accurately be tapered to the final spacing that can produce imaging signal.In addition, if the sample surfaces big rise and fall, generally also need could obtain greater than the high voltage of 18V bigger probe-sample interval range of adjustment with the tracking sample surfaces than macrorelief.
Above-mentioned to high-tension dependence greater than 18V; Cause control circuit must use the high voltage operational amplifier; And high voltage operational amplifier generally all is nothing like low voltage operational amplifier in importances such as noise, speed, precision, power consumptions, and price wants much expensive.So the scanning probe microscopy made from high voltage operational amplifier is far short of what is expected, also expensive a lot of at the scanning probe microscopy of just making than full low voltage operational amplifier aspect performance and the quality.
Summary of the invention
Scanning probe microscopy need use high-tension shortcoming in the prior art in order to overcome in the present invention, and a kind of scanning probe microscopy mirror body that need not high voltage control is provided.
The present invention breaks away from the technical scheme that high-tension dependence is adopted:
The present invention's transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth comprises probe, sample, also comprises and stand side by side and be fixed in two piezo tube on the pedestal; Probe and sample are arranged at the free end of these two piezo tube respectively; Said probe is vertical with the axis direction of said two piezo tube with the gap adjustment direction of sample room, comprises an X location, a Y location and a Z location that one or split are provided with in said two piezo tube at least.
Described two piezo tube are two identical XYZ positioning and voltage pipes.
Can set up mass between said probe or sample and its residing piezo tube.
The present invention breaks away from the another kind of technical scheme that high-tension dependence is adopted:
The present invention's transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth comprises probe, sample, also comprises pedestal and stand and be fixed in the XYZ positioning and voltage pipe on the pedestal and stand with this XYZ positioning and voltage tube side-by-side and be fixed in the vertical rod on the said pedestal; Probe and sample are arranged at the free end of said XYZ positioning and voltage pipe and vertical rod respectively, and said probe is vertical with the axis direction of said XYZ positioning and voltage pipe with the gap adjustment direction of sample room.
Can set up mass between said probe and its residing XYZ positioning and voltage pipe.
The present invention breaks away from another technical scheme that high-tension dependence is adopted:
The present invention's transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth comprises probe, sample, also comprises pedestal and stand and be fixed in the XYZ positioning and voltage pipe on the pedestal and stand with this XYZ positioning and voltage tube side-by-side and be fixed in the vertical rod on the said pedestal; Sample and probe are arranged at the free end of said XYZ positioning and voltage pipe and vertical rod respectively, and said probe is vertical with the axis direction of said XYZ positioning and voltage pipe with the gap adjustment direction of sample room.
Can set up mass between said sample and its residing XYZ positioning and voltage pipe.
The present invention's principle of work of transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth is:
Piezo tube is in length during greater than diameter, and the flexible scope of its axis direction (Z direction, claim again vertically or axially) is less than the sweep limit of laterally (with axial vertical direction, claiming the XY direction again).The axial piezoelectricity telescopic displacement Δ L of piezo tube equals: Δ L=d
31LV/d, wherein L is the length of piezo tube, d
31Be piezoelectric modulus, d is the piezo tube wall thickness, and V is an impressed voltage.The horizontal piezoelectricity telescopic displacement Δ X of piezo tube equals: Δ X=Δ L (2 * 2
0.5/ π) L/D=0.9 Δ L * L/D, wherein D is the internal diameter of piezo tube.Hence one can see that: when the length of piezo tube is bigger when a lot of than its internal diameter, what equal impressed voltage can make piezo tube laterally moves Δ X much larger than moving axially Δ L.Utilize this principle, can the adjusting of probe-sample interval be realized that along its axial piezoelectricity is flexible changing the present invention into realizes along its horizontal scanning through piezo tube by traditional piezo tube of passing through.That is: the adjusting of probe-sample interval is provided with by traditional axial (vertically) and makes horizontally set into, and this makes the range of adjustment of probe-sample interval just can obtain bigger raising need not increasing under the voltage condition.Because piezo tube laterally has two degree of freedom, one of them is used for the adjusting of probe-sample interval, and another still can be used for the scanning of probe along sample surfaces.The scanning vertical with this direction of scanning provides (sweep limit of this direction reduces to some extent, but because the sweep limit of another direction of scanning does not subtract, the large scale information of sample can all not lost) by the axial stretching of piezo tube.
The adjusting of the probe-sample interval on a large scale that so obtains; Can make probe and sample under low driving voltage, just can realize slightly approaching with the inertia step-by-step system each other, can also under low pressure realize carefully approaching and the imaging function surperficial the sample macrorelief by mass.
The present invention can also effectively suppress the temperature drift of probe-sample interval.So the probe-sample interval of tradition scanning probe microscopy is because be the inhomogeneous thermal stability that can influence probe-sample interval of expanding with heat and contract with cold of axial adjustment piezo tube length direction.And the length variations of probe-sample interval of the present invention and piezo tube is irrelevant; Only relevant with the piezo tube or the spacing of vertical rod between the foothold on the pedestal of sample by supporting probe; And this spacing may diminish to and is approximately zero; Thereby it is very little to make that probe-sample interval is acted upon by temperature changes, and can further suppress the temperature drift of probe-sample interval through selecting the low material pedestal of thermal expansivity for use.
We utilize the fully low pressure low temperature drift of transposition in length and breadth scanning probe microscopy mirror body of the present invention; All with control high order graphite (HOPG) sample is carried out the imaging of scanning-tunnelling electric current less than the low voltage drive of 18V; Under atmospheric environment, just obtain the atom definition image of very high-quality, seen accompanying drawing 3.
Compared with present technology, beneficial effect of the present invention is embodied in:
(1) depress in same electrical, the adjustable extent of probe-sample interval is higher than the adjustable extent that prior art provides.
(2) need just not can be made into a complete set of system fully, realize slightly approaching, carefully approach and, can use that price is low, performance is high, the measured low-voltage device of matter is made whole required circuit the imaging on macrorelief surface greater than the high voltage of 18V.
(3) probe-sample interval has the temperature stability of height.
(4) used atmosphere PSTM that the present invention processes that the imaging data of high order graphite (HOPG) sample is shown:
The atom definition image is very clear, and image quality is led over prior art (seeing accompanying drawing 3) really.
Description of drawings
Fig. 1 is the two piezoelectricity casts of the present invention basic structure synoptic diagram of transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth.
Fig. 2 is the single piezoelectricity cast of the present invention basic structure synoptic diagram of transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth.
Fig. 3 is to use the present invention's transposition fully low pressure low temperature drift scanning probe microscopy mirror body scanning-tunnelling map of current picture that the high order graphite sample is become in length and breadth in atmospheric environment.
Label among the figure: the gap adjustment direction between 1 probe, 2 samples, 3 probes and the sample, 4a first piezo tube, 4b second piezo tube, 4c XYZ positioning and voltage pipe, the axis direction of 5 piezo tube, 6 pedestals, 7 vertical rods.
Below through embodiment, the structure accompanying drawing further describes the present invention.
Embodiment
Embodiment 1: two piezoelectricity casts are transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth
Fig. 1 is two piezoelectricity casts basic structure synoptic diagram of transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth.Two piezo tube 4a; 4b stands side by side and is fixed on the pedestal 6; Probe 1 and sample 2 are arranged at the free end of these two piezo tube respectively; Said probe 1 is vertical with the axis direction 5 of said two piezo tube with the gap adjustment direction 3 between the sample 2, comprises an X location, a Y location and a Z location that one or split are provided with in said two piezo tube at least.
During work; Owing to comprise an X location, a Y location and a Z location that one or split are provided with among the first piezo tube 4a and the second piezo tube 4b at least, can make probe 1 carry out X, Y and Z direction location with respect to sample 2 so these two piezo tube cooperate.
The first piezo tube 4a or the second piezo tube 4b are used to regulate the spacing between probe 1 and the sample 2 in the location along the gap adjustment direction 3 of 2 in probe 1 and sample.The first piezo tube 4a or the second piezo tube 4b are used to realize the scanning of probe 1 along sample 2 surfaces in the location along its axis direction.The first piezo tube 4a or the second piezo tube 4b are used to realize probe 1 another scanning along sample 2 surfaces in the location of edge and the perpendicular direction of above-mentioned both direction.Because the first piezo tube 4a or the second piezo tube 4b are at the orientation range along the orientation range of the gap adjustment direction 3 of probe and sample room much larger than their axis directions 5; So need just can be so that enough big piezoelectricity minute adjustment scope can not arranged between probe 1 and the sample 2 greater than the high voltage of 18V; Accomplish the thin tuning task later of slightly approaching between probe 1 and the sample 2, also can accomplish imaging task sample macrorelief surface.
In addition; The first piezo tube 4a and second foothold of piezo tube 4b on pedestal 6 can lean on very near (less than 5 millimeters); Probe 1 and sample 2 are little with the expand with heat and contract with cold variation of probe-sample interval of producing of pedestal 6 when temperature variation; Temperature resistance with height floats ability, particularly when pedestal is processed by the low thermal coefficient of expansion material.The first piezo tube 4a or the second piezo tube 4b also are chosen as the same piezo tube, further suppress probe 1 and the thermal drift of sample 2 in the direction of scanning.
The gap adjustment direction 3 of probe shown in Figure 1 and sample room is along the orientation of the first piezo tube 4a and the second piezo tube 4b, but also can be perpendicular to this orientation (promptly perpendicular to paper).
Embodiment 2: single piezoelectricity cast is transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth
Two piezo tube among the embodiment 1; If one of them elects XYZ positioning and voltage pipe as, then another piezo tube needn't have positioning function, and available arbitrary vertical rod 7 replaces; Constitute single piezoelectricity cast transposition fully low pressure low temperature drift scanning probe microscopy mirror body in length and breadth, see accompanying drawing 2.Specific practice is: XYZ positioning and voltage pipe 4c and vertical rod 7 are stood side by side and are fixed on the pedestal 6; Probe 1 and sample 2 are arranged at the free end of said XYZ positioning and voltage pipe 4c and vertical rod 8 respectively; Probe 1 also can be exchanged with the position of sample 2, and said probe 1 is vertical with the axis direction of said XYZ positioning and voltage pipe 4c with the gap adjustment direction 3 of 2 in sample.
The gap adjustment direction 3 of probe shown in the accompanying drawing 2 and sample room is along the orientation of piezo tube 4c and vertical rod 7, but also can be perpendicular to this orientation (promptly perpendicular to paper).
Embodiment 3: the fully low pressure low temperature drift of the transposition in length and breadth scanning probe microscopy mirror body with inertia step motor
Can set up mass between the free end of the piezo tube described in the embodiment 1-2 and probe that is provided with on it or the sample, constitute probe-sample and slightly approach the inertia step motor.