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In the past two years, a reel-to-reel (R2R) scanning hall probe microscope (SHPM) measurement system has been developed and routinely used at the University of Houston for continuous and 100% testing of REBCO-coated conductors. The background magnetic field interference has been eliminated by introducing FFT into the current density calculation. The noise has been reduced by a factor of 5 after customizing the motor driver. Moreover, since the data acquisition module has been upgraded to 100 kSPS sampling rate, the resolution has reached 0.06 mm2 under the measurement configuration of 8 scans per second with scanning range of 18 mm and tape motion speed of 10 mm/s. Such resolution is likely the best reported by any group at such testing speed. It has enabled our R2R measurement system to obtain detailed current density map of narrow wires and striated multifilament tapes. With the features, the R2R SHPM is turning out to be very valuable metrology and quality assurance tool for long REBCO-coated conductors.

The dynamic characteristics of an atomic force probe are important for rapid and accurate measurement in white light interference (WLI) based atomic force microscope (AFM). The tip of the probe will fly from the surface when its dynamic characteristics are poor, which will cause measurement error. Generally such tip flight can be avoided by reducing the scanning speed, which will decrease the error at the cost of measurement efficiency. In this paper, a dynamical model of atomic force probe is presented to analyze the causes of tip flight in the measurement process. A numerical simulation is performed on a typical sample surface to investigate the influence of profile, preloading and probe parameters on scanning speed. Experimental testing is conducted on a self-developed WLI based AFM, and the experimental results agree well with that of the theory. The maximum scanning speeds of the probe for a sample are tested under certain conditions. It is shown that for a certain probe, the tip flight occurs at the upwards points of the measured sample when the scanning speed exceeds the critical speed, which is constrained by the preloading.

Within the last three decades Scanning Probe Microscopy has been developed to a powerful tool for measuring surfaces and their properties on an atomic scale such that users can be found nowadays not only in academia but also in industry. This development is still pushed further by researchers, who continuously exploit new possibilities of this technique, as well as companies that focus mainly on the usability. However, although imaging has become significantly easier, the time required for a safe approach (without unwanted tip-sample contact) can be very time consuming, especially if the microscope is not equipped or suited for the observation of the tip-sample distance with an additional optical microscope. Here we show that the measurement of the absolute tip-sample capacitance provides an ideal solution for a fast and reliable pre-approach. The absolute tip-sample capacitance shows a generic behavior as a function of the distance, even though we measured it on several completely different setups. Insight into this behavior is gained via an analytical and computational analysis, from which two additional advantages arise: the capacitance measurement can be applied for observing, analyzing, and fine-tuning of the approach motor, as well as for the determination of the (effective) tip radius. The latter provides important information about the sharpness of the measured tip and can be used not only to characterize new (freshly etched) tips but also for the determination of the degradation after a tip-sample contact/crash.

A magnetic measuring microscope with a spatial resolution of 3 μm in the determination of current dipole coordinates is described. For the primary transducer, a film Hall transducer with sensitive-zone dimensions of 250 × 400 μm is used. The transducer is positioned at a distance of 3 mm from the plane of scanning. Superresolution as compared to the sensor dimensions and distance from the object was reached by using a priori information about the scanned object. A means of calibration of the magnetic microscope and measurement of its metrological characteristics is proposed. The effectiveness and consistency of the obtained estimate of coordinates is shown by comparison of the random error in measurements of current dipole coordinates with the Cramer–Rao bound. The measuring microscope can be applied in studying elements of functional electronics.

Crack propagation around the stress concentration area causes fatigue failure. Non-destructive method is necessary for monitoring structure fatigue before destruction. We focused on a magnetic non-destructive evaluation method for crack growth. In order to understand the relation between crack propagation and changes in magnetic flux density, we observed the position of the positive and negative magnetic flux density distributions around the crack of tool steel (SCM440) plate using a scanning Hall probe microscope (SHPM). We found that the vertical component of the three-dimensional magnetic flux density moved as the crack growth. Furthermore, the magnetic component which is parallel to the tensile stress appeared just before destruction of the specimen.

Two reel-to-reel critical current (Ic) measurement systems for REBCO coated conductors (CCs) have been developed at the University of Houston. The first reel-to-reel system is based on the traditional four-probe method with a background field (up to 5 T) perpendicular to the tape surface. At present, in-field critical current of HTS tapes is measured typically over short samples cut from the ends of long tapes. Continuous in-field current transport testing of long tapes is done only at field lower than 1 T. Previously we found that Ic at low temperature in high fields, which is important for magnet applications, is strongly related to the Ic at 77 K, 3 T (perpendicular to tape) while not as much to 77 K, self-field Ic. Hence, we established a reel-to-reel system for measurement of Ic of CCs at 77 K, (B perpendicular to tape) so that in-field performance of long tapes can be qualified over their entire length and variations in in-field performance at lower temperatures can be accurately determined. The second reel-to-reel system uses a scanning Hall probe microscope (SHPM) and is for two-dimensional critical current density mapping and characterization of multi-filamentary CCs. Critical current distributions in both non-striated and 12-filament laser-striated long CCs have been mapped using this method. A novel iterative data analysis technique that was recently developed has been applied to the analysis of multi-filamentary CCs using the SHPM system.

Non-destructive stress measurement methods have been developed. However, there are a few approaches into the effect of stress direction on the nondestructive physical factors. In the present work, a non-destructive and non-contact method using three-dimensional magnet microscopy was applied to stress evaluation of an as-received tool steel (JIS, SKS93). Three-dimensional components of magnetic fields were observed using a scanning Hall probe microscope in order to find the important component which was related to the tensile stress. The observations were carried out under the tensile stress that was less than the yielding stress of the material. It was found that the magnetic field component that was parallel to a tensile loading direction was strongly correlated to stress values.

The new digital teslameter system (also called Gaussmeter) incorporates a 3-axis Hall probe, analog electronics based on the spinning-current technique, 24-bit analog-to-digital converter, computer, and 7-digit touch-screen display. The Hall probe is a single silicon chip with monolithically integrated horizontal and vertical Hall magnetic sensors and a temperature sensor. The Hall sensor chip is encapsulated in a robust ceramic package, a version of which is only 250 μm thick. The spinning-current eliminates most of the Hall probe offset, low-frequency noise, and the planar Hall voltage. The errors due to the Hall element non-linearity and the variations in the probe electronics temperatures are eliminated by a calibration procedure based on a three-variable second-order polynomial. The errors due to the angular errors of the Hall probe are eliminated by a calibration of the sensitivity tensor of the probe. These new developments resulted in a teslameter that can measure magnetic field vectors from about 1 μT to 30 T, with the spatial resolution 100 μm, magnetic resolution ±2 ppm of the range, the accuracy ±0.0001% of reading +0.001% of range, temperature coefficient less than 5 ppm/°C, and angular errors less than 0.1 deg.

The app described in this article was presented at the student design competition of the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium. As sponsored by Technical Committee MTT-25 on RF nanotechnology, the competition's objective was to develop user-friendly interfaces to facilitate the design and application of RF nanotechnology. To this end, the app is capable of simulating the capacitance and charge distribution of the probe-sample interaction on a nanoscale in near-field scanning microscopes, such as the scanning microwave microscope (SMM), the atomic force microscope (AFM), and the scanning tunneling microscope (STM).

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The fracture of the atomic-scale contact should be investigated for understanding the mechanism of the mechanical processing. Using a combination of the scanning probe microscope (SPM) with possible high space resolution and the acoustic emission (AE) with high sensitivity for fracture is one of the possible way of investigating the fracture mechanism. When using the SPM, the AE signal might be detected with receiving the AE wave by the piezoelectric tube scanner of the SPM receiving the AE wave, where by the piezoelectric effect the electric signal due to the AE wave is superimposed on the scan signal. Based on that, in this study, a novel method to detect AE signal from the scan signal is proposed. With this method, without changing the SPM body, the AE could be detected, and a two-dimensional AE source location could be possible by using four divided electrodes of the piezoelectric tube scanner. By a simple experiment using the AE wave simulator, the AE signal seems to be detected by the piezoelectric scanner of the SPM. Also, one of the typical data from the experiment suggests the AE source location might be possible. In the experiment of the indentation using atomic force microscope (AFM), which is one of the SPM, the AE signal is observed reproducibly.

Non-destructive evaluation methods using magnetic measurement systems have been developed. However, there are a few approaches to the effect of cracks on magnetic fields during whole fatigue process. In the present work, slit samples of as-received chromium molybdenum steel material (JIS, SCM440) including no retained austenite was fatigue tested. Fatigue process was observed using a scanning Hall probe microscope in order to investigate the effect of cyclic slit opening and crack growth on residual magnetic fields. It is found that the cyclic opening-closing of the slit decreases the magnetic flux density even where no tensile stress was applied.

Small cracks form in steel and then grow to cause failure. It is important to observe the plastic deformation around cracks in order to understand the fatigue level of all kinds of steel components. However, at present, it is not easy to observe the plastic deformation at the crack tip during crack growth. In this study, in order to find a new, non-destructive testing method which is related to the cracks, we investigated the relationship between magnetic fields and plastic deformation around the crack tip. A scanning Hall probe microscope (SHPM) equipped with three-dimensional GaAs film equipment was used to observe the magnetic fields around a crack tip and the plastic deformation induced by Vickers indentations in tool steel specimens (SKS93, JIS B 4404: 2006, equivalent to AISI W4 tool steel). We found that the magnetic fields around the crack tip changed during the crack growth, and also that the decrease in the magnetic fields depends on the plastic deformation size.

A tapping mode scanning probe microscopy (TM SPM) system for surface measurement in nanoscale is developed, of which the main element is a scanning probe consisting of quartz tuning fork and a long sharp tungsten tip. Quartz tuning fork is a very good resonant element with piezoelectrical characteristic, and it acts as an actuator and a force sensor simultaneously in the probe. The vertical spatial resolution of the TM SPM is up to sub-nanometer (0.11 nm) and the measuring force is in micro Newton magnitude (about 30 μN). In the scanning operation, the probe vibrates at its resonant frequency, so that the amplitude or frequency (or phase) of the resonant tuning fork is very sensitive to external forces (Its quality factor in air is about 3138). Using the TM SPM constructed by this probe, silicon samples are scanned. Their topography and phase images which indicate the surface material characteristics are reconstructed effectively with a high resolution and low destructiveness. Soft materials, such as Protein structure can also be scanned theoretically without damage. In addition, because of the using of the long sharp tungsten tip, the system has the capacity of measuring micro structures with large aspect ratio, such as large micro steps, deep micro trenches, etc.

Polarization interferometric nonlinear confocal microscope has been developed to observe a submicron size object in high contrast. The microscope succeeded in resolving the inside of a 200-nm-diameter polymeric nanoparticle. According to CTF (contrast transfer function) measurement and three-dimensional imaging with the microscope, the best spatial resolution for the microscope is 10 nm.

Introducing artificial antidots into superconductors is an effective approach to manipulate vortex matter. It is of importance to study the effect of antidots on the magnetic field of a vortex and its temperature dependence. In our experiment, single vortices pinned at artificial antidots of different sizes as well as vortex pinned by random defects are investigated by using a scanning Hall probe microscope. At a certain height above the superconductor surface, the morphology of the vortices at various temperatures has been directly imaged. We have shown that the magnetic field distribution and its temperature dependences for all pinned vortices are similar. For both types of antidots, the penetration depth, rather than the antidot size, plays a dominant role in determining their vortex size at various temperatures. Ginzburg-Landau simulations well support our experiments. The results set the stage for further theoretical analysis of the local field variations of the pinned vortices with temperature as well as for the design and fine tuning of pinned vortex lattices that can be used as magnetic templates for other systems.

This article presents a review of nonlocal manipulation with the scanning tunneling microscope. We present manipulation of atomic and molecular adsorbates on a range of different surfaces induced either by the intense electric field between the tip and the sample or by the tunneling electrons. We review reports of electron-induced nonlocal manipulation on surfaces such as Au(111), which qualitatively describe the nonlocal effect but without concrete conclusions as to the electron transport process. To unravel and quantify the precise mechanism of manipulation, we concentrate specifically on the case of nonlocal displacement of aromatic molecules on Si(111)-7x7. We show that nonlocal manipulation in this case is a consequence of the lateral transport of hot electrons across the surface as they diffuse away from the initial injection site. In this sense, nonlocal manipulation is a manifestation in real space of the ultrafast dynamics of hot surface charge carriers.

We report on investigations of the quantum Hall chiral edge states using a near-field scanning optical microscope that enables us to irradiate circularly polarized light from the probe tip with spatial resolution below the diffraction limit. We have found a clear evidence for the formation of spin-split incompressible strips near the edge of a two-dimensional electron system in high magnetic fields.

A 12-filament laser striated coated conductor is studied using Scanning Hall Probe Microscopy (SHPM). Remanent field is measured and critical current density distribution is calculated according to the measured field map. The results show that the SHPM technique is very sensitive to defects. A point-like defect can be readily discerned in the magnetic field map, even when the drop in critical current density is small. We also found that the choice of a proper filter is important for obtaining accurate critical current density values, especially for the multifilament superconducting tapes.

A wave optical calculation of the probe size of a low energy scanning electron microscope is presented. The resolution for the optimal aperture was computed and compared with results of standard approaches. The effect of deflection aberrations is also considered, and it was found to be critical for the landing energies below 5eV and fields of view larger than 100 x 100 μm2.

A scanning SQUID probe microscope, in which a superconducting quantum interference device (SQUID) is combined with a scanning probe microscope, has been developed using a needle probe with high magnetic permeability. The probe played a key role of a flux guide from the sample to the SQUID. An rf-SQUID magnetometer used with a substrate resonator had been adopted in the initial setup. The magnetic sensitivity was not so high though the spatial resolution was good. In this paper, the flux transfer from the sample to the SQUID through the probe was investigated by using the magnetic field simulations. The result showed that the flux was decreased by a factor of more than 1,000 from the probe tip to the SQUID. The critical drop was occurred around the end of the probe. It suggested the magnetic coupling between the SQUID and the probe should be improved. The additional gap distance was needed in the initial rf-SQUID because of the thickness of the substrate resonator used with the rf-SQUID. Therefore, new rf-SQUIDs, which could be operated without a resonator, were fabricated to reduce the gap distance between the SQUID and the probe. The gap distance affected the quality of the magnetic images.

This paper is dedicated to develop an atomic force microscope (AFM) system cou-pled with a high resolution optical microscope (OM), which serves to observe AFM image from a desired micro-area. The system employs through-the-lens optical path for detecting atomic force based on optical lever. By switching the objective lenses from low to high magni cation, a micro-area for obtaining AFM image can be easily found. AFM images of magnetic nanodotarrays with 300 nm and 150 nm pitches are obtained from two local micro-areas using the system. The results demonstrate the proposed prototype has the su cient function to nd out a micro-area for obtaining AFM image.

In this study, we tried to develop the scanning near-field polarization microscope (SNPM) and challenge to observe magnetization of the magnetic nanodot in the arrays. The CoPt dot arrays with a size of 25 nm and a pitch of 150 nm were adopted. The nanodots change contrast after changing the direction of the external magnetic field. This implied that our prototyped SNPM system had the resolution of less than 25 nm. So, it is demonstrated that SNPM is an effective tool for the observation of magnetization of the magnetic nanodot on the nanometer scale.

The process of scanning a focused light beam by a metal-coated fiber probe with a subwavelength aperture is simulated using the finite element method for the two- and three-dimensional cases. Intensity pictures of a focal spot are obtained. For various configurations of the probes, sensitivity to electromagnetic components is investigated. Qualitative differences in the results of the two- and three-dimensional simulation are discussed. In the two-dimensional case, the probe response is found to be independent of the aperture size. However, in the three-dimensional case, the probe response depends heavily on the aperture diameter.

Summary This paper presents a method for differential magnetic force microscope imaging based on a two-pass scanning procedure to extract differential magnetic forces and eliminate or significantly reduce background forces with reversed tip magnetization. In the work, the difference of two scanned images with reversed tip magnetization was used to express the local magnetic forces. The magnetic sample was first scanned with a low lift distance between the MFM tip and the sample surface, and the magnetization direction of the probe was then changed after the first scan to perform the second scan. The differential magnetic force image was obtained through the subtraction of the two images from the two scans. The theoretical and experimental results have shown that the proposed method for differential magnetic force microscope imaging is able to reduce the effect of background or environment interference forces, and offers an improved image contrast and signal to noise ratio (SNR). SCANNING 37:112–115, 2015. © 2015 Wiley Periodicals, Inc.

In this paper, we report a miniaturized laser scanning microscope. Unlike conventional microscopes, the optical fiber used here for the excitation laser and signal’s transmission largely improves our microscope’s mobility, and thus eliminates the space constraints of the sample stage. This miniaturized microscope can be motorized along XYZ axis and rotated in theta direction. Based on this modified microscope, we take images of test targets and a micrometer, and compare the resolution and signal to background ratio between its confocal and non-descanned detection modules. We also present the imaging results of Hela cells on a tilted sample stage to simulate the imaging of large and irregular samples. Therefore, this miniaturized microscope has the potential to be utilized for in vivo imaging of large animals.

Electric force microscope (EFM) testing is based on Coulombic force interactions between an EFM probe and a test point. An electric signal on an interconnected line creates an electric force between the tip and the device under test which causes a detectable bending of the cantilever. This bending amount is optically detected and electrically analyzed by a lock-in amplifier. In capacitive coupling method, an electrode is placed in close proximity to a pad on the wafer. The voltage transients on the pad induce weak displacement currents on the electrode. This effect can be used to detect electrical pulses propagating through an IC. For current measurements, scanning magnetoresistive probe has also been suggested to detect currents in a contactless manner.

In this paper, we propose a finite-impulse-response (FIR)-based feedforward control approach to mitigate the acoustic-caused probe vibration during atomic force microscope (AFM) imaging. Compensation for the extraneous probe vibration is needed to avoid the adverse effects of environmental disturbances such as acoustic noise on AFM imaging, nanomechanical characterization, and nanomanipulation. Particularly, residual noise still exists even though conventional passive noise cancellation apparatus has been employed. The proposed technique exploits a data-driven approach to capture both the noise propagation dynamics and the noise cancellation dynamics in the controller design, and is illustrated through the experimental implementation in AFM imaging application.

It was found that the results of magnetic force microscope (MFM) imaging weredifferent with the probe scanning directions, and the images were often distorted. Thispaper studied the effect of scanning directions on the MFM imaging, and a method forthe distortion compensation was proposed to reduce the errors. In the study, threedifferent scanning directions with the angles of 0°, 45° and 90°, were used to measurethe magnetic force distribution of a magnetic sample with a regular structure. Thetheoretical and experimental results have shown that the scanning direction parallel tothe magnetic structure will cause a minimum phase shift difference and lead to a structure distortion. With the proposed compensation method, the distortion structureswere corrected and the effect of scanning directions on the MFM imaging wassignificantly reduced. This work provides a way to obtain the correct images ofmagnetic structures using an MFM and to improve the imaging quality in a wide range of MFM applications.

In this paper, a magnetic force microscope (MFM) was developed for applications in liquid environment. The 3D structure of the developed MFM system was designed first and then the components of every part were machined and assembled. The laser beam horizontally reached the mirror and reflected vertically to the cantilever of the probe to reduce the effect of air, glass and liquid refraction. This research focuses on the design of a specific MFM system to obtain the magnetic force images in liquids.

International audience; The design, fabrication and experimental validation of a novel near-field scanning millimeter-wave microscope (NSMM) built inside a scanning electron microscope (SEM) is presented. The instrument developed can perform hybrid characterizations by providing simultaneously atomic force, complex microwave impedance and electron microscopy images of a sample with nanometer spatial resolution. By combining the measured data, the system offers unprecedentable capabilities for tackling the issue between spatial resolution and high frequency quantitative measurements.

This paper presents a novel low cost three dimensional near-field scanning system consisting of a near field scanner and a three dimensional magnetic probe which reduces the large scanning time of the existing near field scanning systems and increases the spatial resolution. The paper focuses on the design, calibration and validation of a printed circuit three dimensional magnetic field probe. The proposed probe is printed on both sides an FR4 substrate of 3.2mm height. The total dimensions of the probe are 9×9×3.2mm3. The antenna factor of the designed probes is calculated using TEM cell for a frequency range from 10 MHz to 1 GHz. The proposed scanning system is validated by mapping the magnetic field above a wire over ground structure.

The method for measuring the electron distribution density in a probe of a low voltage scanning electron microscope is proposed. It is shown that a focused probe has the Gaussian shape. A defocused probe can be presented as several Gaussian probes of different intensities shifted relative to each other.

Graphene micro-Hall probes were developed for a scanning Hall probe microscope system and used for the direct magnetic imaging domains of demagnetized NdFeB permanent magnet for the first time. The Hall coefficient and minimum magnetic field resolution of graphene Hall probes at 1 kHz were found to be 0.18 Ω/G and 0.20 G / Hz for a drive current of 3 μA at room temperature in vacuum. The magnetic domains in NdFeB demagnetized magnet were observed at 300 K, 126 K and 3 K successfully.

Failure of dies and moulds is caused by wear and deformation during the metal sheet forming process. Die wear takes various forms, and the contact conditions in die parts affect the strength of the components. Non-destructive evaluation methods that can be related to contact conditions are necessary to study and understand the phenomena caused by the contact stresses. In the present work, a newly developed scanning Hall probe microscope (SHPM) equipped with a GaAs film sensor was used to observe the three-dimensional magnetic fields in tool steel plates before and after contact tests at room temperature in air. Around the contact test area, changes in ‘S’ and ‘N’ poles generated by magnetisation using a square magnet block were investigated. It was found that the intensity of three-dimensional magnetic fields is only slightly affected by the spherical Hertzian contact. However, all of the three-dimensional components of the magnetic fields change significantly. The extent of the changes depends no...

Cyclic stresses around welding joint part affect the strength of mechanical components. In order to understand the fatigue phenomena caused by the cyclic stresses, non-destructive methods that can be related to number of stress cycles are necessary. In the present work, we used a newly developed scanning Hall probe microscope (SHPM) equipped with a GaAs film sensor and observed three-dimensional magnetic fields of the specimen before and after four-point fatigue testing at room temperature in air. Low carbon steel plates (JIS SS400) were used in the experiments. It was found that the intensity of the magnet field in a direction perpendicular to the specimen surface was strongly affected by the fatigue cycles. This result means that we can evaluate the fatigue in welding joint area using quantitative magnetic field measurements. Furthermore, it was discovered that the key factor to evaluate the fatigue is the range between ‘S’ and ‘N’ (‘peak to bottom’ values) of the magnetic fields. The three-dimensional ...

In this paper, improvement of the magnetic field detection accuracy of Scanning Hall probe microscopy (SHPM) by reducing the lift-off distance was studied. The distribution of the three dimensional residual magnetic flux density components was observed around the magnetization point on the surface of carbon tool steel at several lift-off distances ranging from 350 μm to 1500 μm. The observation at 350 μm lift-off distance achieved more 2.7 times intensity than at 1500 μm lift-off distance and a correlation between the magnetic flux density and the lift-off distance was found. Based on the 350 μm lift-off observation, a successful observation of magnetization caused by plastic deformation around the Vickers indentation was succeeded to be performed.

Methods of determining the basic metrological characteristics of a near-field scanning optical microscope, i.e., scale factor and spatial resolution, defined as the diameter of the optical probe, are proposed. The use of the proposed method for calibration of the near-field scanning optical microscope directly in the course of measurements of the parameters of biological objects is investigated.

Recently a multi-beam scanning electron microscope (MBSEM) has been developed, which delivers 196 focused beams to a sample, each of which has around 1nA. In this article a design for an optical system is described and analyzed which can focus all these beams onto a single spot, using an array of micro electron lenses. Although each individual micro lens will be of lower quality than a single macro objective lens, a system is obtained with larger beam current than the conventional SEM. The goal set in an example design is to focus a total current of 200nA within 50nm at a landing energy of 500eV.

A four-channel Kirkpatrick-Baez microscope working at multiple energy bands is developed for multiframe X-ray imaging diagnostics at the Shenguang-II laser facility. The response to the multiple energy bands is realized by coating the double-periodic multilayers on the reflected surfaces of the microscope. Because of the limited size of the microstrips in the X-ray framing camera, the image separation is controlled by the conical angle of the reference cores during microscope assembly. This study describes the optical and multilayer design, assembly, and alignment of the developed microscope. The microscope achieves a spatial resolution of 4-5 mm in the laboratory and 10-20 mm at Shenguang-II laser facility within a 300 mm field of view. The versatile nature of the developed microscope enables the multiple microscopes currently installed in the laser facility to be replaced with a single, multipurpose microscope.

Atomic force microscope (AFM) – is device widely used in many scientific fields for nano-scale surface scanning. AFM also can be used to probe mechanical stiffness, electrical conductance, resistivity, magnetism and other properties. The main limitation of AFM implementation is relatively low scanning speed. This speed depends from dynamical characteristics of AFM sensor and from surface roughness of scanned sample. Our research is focused on increasing scanning speed of AFM microscope assuming AFM mechanical sensor as sensitive dynamic system. Our proposed method enables increase of scanning speed by modifying some features of mechanical sensor by adding non-linear force to the surface of cantilever of AFM sensor. Proposed method is modelled theoretically using Simulink features. This paper presents research of mechanical sensor of AFM. After performed research, obtained results are presented on graphical form. At the end of paper discussion presented and conclusions are drawn.

Introducing artificial antidots into superconductors is an efficient way to improve the superconducting properties for application. However, besides the pioneering theoretical studies, the fundamental question concerning how many vortices can be trapped by the antidot still needs to be further clarified from an experimental point of view. In this study, by the e-beam lithography, antidots with different sizes and shapes are fabricated in a superconducting Pb film. The vortex distribution at antidots has been directly imaged using the low-temperature scanning Hall probe microscope. A universal scaling behavior is found that the number of trapped vortices mainly depends on the size of the antidots, irrespective of the shape of antidots. The results shed light on the study of vortex pinning at artificial pinning centers, which is important for practical applications.Introducing artificial antidots into superconductors is an efficient way to improve the superconducting properties for application. However, besides the pioneering theoretical studies, the fundamental question concerning how many vortices can be trapped by the antidot still needs to be further clarified from an experimental point of view. In this study, by the e-beam lithography, antidots with different sizes and shapes are fabricated in a superconducting Pb film. The vortex distribution at antidots has been directly imaged using the low-temperature scanning Hall probe microscope. A universal scaling behavior is found that the number of trapped vortices mainly depends on the size of the antidots, irrespective of the shape of antidots. The results shed light on the study of vortex pinning at artificial pinning centers, which is important for practical applications.