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Shear-force acoustic near-field microscopy (SANM) is employed to monitor stochastic formation and post dynamic response of a water meniscus that bridges a tapered gold probe (undergoing lateral oscillations of a few nanometers amplitude at constant frequency) and a flat (gold or silicon oxide) substrate. As the probe further approaches the substrate, its amplitude decreases. Shear forces (of yet unknown precise origin) are typically invoked to explain the apparently pure damping effects affecting the probe's motion. Herein, SANM measurements underscore instead the role of near-field acoustic emission from the water meniscus as an elastic energy dissipation channel involved in shear interactions. A simplified thermodynamic argument is provided to justify the formation of a water meniscus between the probe and the sample once they are at sufficient separation distance. The reported measurements focus on the role played by the tip's geometry (by using probes of slender and chubby apex termination). The results shed some light on the potential origin of the so-called shear forces, invoked in many scanning probe microscopy applications, but not yet well understood. [ABSTRACT FROM AUTHOR]

The effect of carbon coating on a surface structure of a high-dose implanted/annealed silicon carbide (SiC) during annealing was examined using scanning probe microscopy (SPM), deep-ultraviolet (DUV) Raman spectroscopy, and transmission electron microscopy (TEM). In SPM, the surfaces of 500- and 30 °C-implanted/annealed SiC samples without coating exhibited a periodic-step structure and granular structure, respectively. The difference between these surfaces is attributed to the absence or presence of residual implantation damage. In contrast, surface flatness was maintained in the 500 °C-implanted/annealed SiC sample with carbon coating. However, the surface of the coated 30 °C-implanted/annealed SiC sample exhibited a geometric structure with a lattice pattern parallel to the ⟨ 11 2 ¯ 0 ⟩ axes. The DUV Raman spectra and TEM images indicated that the implanted layer of this sample metamorphosed into a mixture of 3C-SiC twin domains and amorphous-SiC regions. During the cooling process after annealing, the 3C-SiC region was more raised than the amorphous-SiC region owing to the difference in the thermal expansion coefficients, thus resulting in the generation of a geometric surface structure. In the metamorphosed implanted layer, the carbon coating does not completely prevent surface roughening. [ABSTRACT FROM AUTHOR]

The current focus in Autonomous Experimentation (AE) is on developing robust workflows to conduct the AE effectively. This entails the need for well-defined approaches to guide the AE process, including strategies for hyperparameter tuning and high-level human interventions within the workflow loop. This paper presents a comprehensive analysis of the influence of initial experimental conditions and in-loop interventions on the learning dynamics of Deep Kernel Learning (DKL) within the realm of AE in scanning probe microscopy. We explore the concept of the "seed effect," where the initial experiment setup has a substantial impact on the subsequent learning trajectory. Additionally, we introduce an approach of the seed point interventions in AE allowing the operator to influence the exploration process. Using a dataset from Piezoresponse Force Microscopy on PbTiO3 thin films, we illustrate the impact of the "seed effect" and in-loop seed interventions on the effectiveness of DKL in predicting material properties. The study highlights the importance of initial choices and adaptive interventions in optimizing learning rates and enhancing the efficiency of automated material characterization. This work offers valuable insights into designing more robust and effective AE workflows in microscopy with potential applications across various characterization techniques. [ABSTRACT FROM AUTHOR]

Enantiospecific effects play an uprising role in chemistry and technical applications. Chiral molecular networks formed by self‐assembly processes at surfaces can be imaged by scanning probe microscopy (SPM). Low contrast and high noise in the topography map often interfere with the automatic image analysis using classical methods. The long SPM image acquisition times restrain Artificial Intelligence‐based methods requiring large training sets, leaving only tedious manual work, inducing human‐dependent errors and biased labeling. By generating realistic looking synthetic images, the acquisition of real datasets is avoided. Two state‐of‐the‐art object detection architectures are trained to localize and classify chiral unit‐cells in a regular molecular chiral network formed by self‐assembly of linear molecular bricks. The comparison of different architectures and datasets demonstrates that the training on purely synthetic data outperforms models trained using augmented datasets. A Faster R‐CNN model trained solely on synthetic data achieved an excellent mean average precision of 99% on real data. Hence this approach and the transfer to real data show high success, also highlighting the high robustness against experimental noise and different zoom levels across the full experimentally reasonable parameter range. The generalizability of this idea is demonstrated by achieving equally high performance on a different structure, too. [ABSTRACT FROM AUTHOR]

An advanced scanning probe microscopy system enhanced with artificial intelligence (AI‐SPM) designed for self‐driving atomic‐scale measurements is presented. This system expertly identifies and manipulates atomic positions with high precision, autonomously performing tasks such as spectroscopic data acquisition and atomic adjustment. An outstanding feature of AI‐SPM is its ability to detect and adapt to surface defects, targeting or avoiding them as necessary. It is also designed to overcome typical challenges such as positional drift and tip apex atomic variations due to the thermal effects, ensuring accurate, site‐specific surface analysis. The tests under the demanding conditions of room temperature have demonstrated the robustness of the system, successfully navigating thermal drift and tip fluctuations. During these tests on the Si(111)‐(7 × 7) surface, AI‐SPM autonomously identified defect‐free regions and performed a large number of current–voltage spectroscopy measurements at different adatom sites, while autonomously compensating for thermal drift and monitoring probe health. These experiments produce extensive data sets that are critical for reliable materials characterization and demonstrate the potential of AI‐SPM to significantly improve data acquisition. The integration of AI into SPM technologies represents a step toward more effective, precise and reliable atomic‐level surface analysis, revolutionizing materials characterization methods. [ABSTRACT FROM AUTHOR]

The dielectric gap between the scanning probe microscopy (SPM) tip and the surface of a ferroelectric using conductive atomic force microscopy and piezoresponse force microscopy (PFM) is investigated. While the gap functions as a dielectric layer, it also allows tunneling current to inject charges into the ferroelectric when a critical loading force between 10–20 µN is applied to a tip with a radius of 25 nm under a bias voltage of 0.5 V. It is observed that the permittivity of the dielectric gap determines the coercive voltage measured by the piezoresponse hysteresis loop. While such studies done in air often produce coercive voltages much larger than those studied for the same materials in capacitor‐based studies, the use of high permittivity media such as water (ɛr = 79) or silicone oil (ɛr = 2.1‐2.8) produces coercive fields that more closely match those measured in conventional capacitor‐based polarization hysteresis loop measurements. Furthermore, using water as a dielectric medium in PFM imaging enhances the accuracy in extracting the amplitude and phase data from periodically poled lithium niobate crystals. These findings provide insight into the nanoscale phenomena of polarization switching instigated by the SPM tip and provide a pathway to improved quantitative studies. [ABSTRACT FROM AUTHOR]

In scanning electrochemical microscopy (SECM), the addition of a redox active species plays an essential role. Those deliberately added mediators may alter results in SECM studies. In investigations of lithium‐ion battery (LIB) materials, especially of the positive electrode, the oxidation potentials of commonly used mediator substances such as ferrocene are located within the operation potential of the electrode. Thus, they possibly interfere with the regular charge/discharge processes. In situ studies are therefore in need of approaches reducing or eliminating the use of mediators. Within this publication, a novel mediator dosing (MD) concept is introduced. A capillary was closely positioned at the tip of the scanning probe. By gravity flow, stable flow rates of mediator solution of up to 32.4±0.6 μL h−1 were achieved. These low amounts were found to be sufficient to form a ferrocene zone at the probe tip enabling feedback mode SECM measurements with comparable quality to measurements directly in ferrocene solution. Proof of concept experiments were conducted by investigation of a thin‐film electrode with a micro‐structured surface. Furthermore, the MD concept was applied in imaging experiments of a commercially available LIB graphite electrode. [ABSTRACT FROM AUTHOR]

Epoxyamine matrix-based composites containing 15 wt% of Fe nanoparticles and 1.5 or 2 wt% of carbon nanotubes, as well as composites containing only Fe particles, have been studied using microwave methods and various scanning probe microscopy techniques, such as scanning capacitance microscopy and scanning Kelvin probe force microscopy. The composites were prepared using technological methods that improve their homogeneity. Probe current dependences investigated by applying different voltages to the probe in the Kelvin probe force microscopy mode have shown that the falling regions of the dependences at both positive and negative values of the bias voltage are found only for the sample containing both the Fe particles and the CNT in the "soft epoxy" matrix. Microwave measurements of the transmission and reflection coefficients were performed in the frequency range from 26 to 38 GHz. The field dependences of the microwave power dissipation have been plotted. The ferromagnetic resonance in the composites has been investigated. Frequency dependences of the complex dielectric permittivity of the composites have been determined. Microwave properties of the CNT-containing and CNT-free composites have been compared. [ABSTRACT FROM AUTHOR]

Molecular field-coupled nanocomputing (molFCN) encodes information in the molecule charge distribution and elaborates it through electrostatic coupling. Despite the advantageous sub-nanometric size and low-power dissipation, only a few attempts have been made to validate the technology experimentally. One of the obstacles is the difficulty in measuring molecule charges to validate information encoding or integrate molFCN with complementary-metal-oxide-semiconductor (CMOS). In this work, we propose a paradigm preserving the advantages of molFCN, which exploits the position of waiving molecules to augment the information encoding. We validate the paradigm, named bend-boosted molFCN, with density functional theory using 6-(ferrocenyl)hexanethiol cations. We demonstrate that the encoded information can be electrically read by constituting a molecular junction. The paradigm is compatible with the charge-based molFCN, thus acting as a readout system. The obtained results favor the experimental assessment of the molFCN principle through scanning probe microscopy techniques and the design of molFCN-CMOS heterogeneous circuits. [ABSTRACT FROM AUTHOR]

Electron, optical, and scanning probe microscopy methods are generating ever increasing volume of image data containing information on atomic and mesoscale structures and functionalities. This necessitates the development of the machine learning methods for discovery of physical and chemical phenomena from the data, such as manifestations of symmetry breaking phenomena in electron and scanning tunneling microscopy images, or variability of the nanoparticles. Variational autoencoders (VAEs) are emerging as a powerful paradigm for the unsupervised data analysis, allowing to disentangle the factors of variability and discover optimal parsimonious representation. Here, we summarize recent developments in VAEs, covering the basic principles and intuition behind the VAEs. The invariant VAEs are introduced as an approach to accommodate scale and translation invariances present in imaging data and separate known factors of variations from the ones to be discovered. We further describe the opportunities enabled by the control over VAE architecture, including conditional, semi-supervised, and joint VAEs. Several case studies of VAE applications for toy models and experimental datasets in Scanning Transmission Electron Microscopy are discussed, emphasizing the deep connection between VAE and basic physical principles. Python codes and datasets discussed in this article are available at https://github.com/saimani5/VAE-tutorials and can be used by researchers as an application guide when applying these to their own datasets. [ABSTRACT FROM AUTHOR]

This study compares different types of scanning probe microscopy (SPM) probes according to the function of the surface layer at the tip apex. Three main types of SPM probes were analyzed: scanning tunneling microscopy (STM) tungsten probes, conductive atomic force microscopy (AFM) probes, and non-conductive AFM probes. The tungsten STM probes were coated with a graphite layer to simulate the effects of carbonization. The tested AFM probes were specifically NenoProbe conductive AFM probes (platinum-coated tip) and Akiyama non-conductive AFM probes coated with gold. The gold coating is intended to improve surface conductivity and help achieve a homogeneous, oxidation-resistant surface. The three samples were measured in a field emission microscope to study their current-voltage characteristics. The obtained current-voltage characteristics were tested and analyzed by the Forbes field emission orthodoxy test, providing the field emission parameters that correlate with the state of the scanning probe tip. In this study, the most important parameter is the formal emission area parameter, which indicates the formal tunneling current density through the probe tip-sample nanogap. For an STM tip, this reflects the size and shape of the region from which electrons tunnel to the sample surface. If this area is larger than expected or desired, it may indicate problems with tip function or tip wear. This information is critical for evaluating the performance and accuracy of the STM tip and can help diagnose problems and optimize its function. [ABSTRACT FROM AUTHOR]

Cu-Cr-Zr alloys have excellent electrical and thermal conductivity. So, these alloys possess major contribution to industrial applications which were fabricated with the help of the laser powder bed fusion (LPBF) technique. However, during the printing process, the geometries were affected by cavity formation, poor wettability between the particles, etc. In this study, LPBF parameters such as laser power (300, 350 and 400 W), exposure time (200, 300 and 400 µs) and overlapping rate (10, 30 and 50%) were examined to prepare a fully dense part with minimum defects. Parameters evaluated for the combined influence of process parameters were relative density, nanohardness and surface roughness. The effects of different combinations of input parameters on defect formations and micropores were also demonstrated. Furthermore, observations from 2D scanning probe microscopy (SPM) images and 3D topography were used to evaluate the surface roughness. The combination of 400-W laser power, 300-μs exposure time and 50% overlapping rate has led to highly dense parts with a reduced surface roughness of 11.32 µm and also with maximum reduced modulus and nanohardness of 191.4 and 5.8 GPa. [ABSTRACT FROM AUTHOR]

Phosphorus pentamers (cyclo-P5) are unstable in nature but can be synthesized at the Ag(111) surface. Unlike monolayer black phosphorous, little is known about their electronic properties when in contact with metal electrodes, although this is crucial for future applications. Here, we characterize the atomic structure of cyclo-P5 assembled on Ag(111) using atomic force microscopy with functionalized tips and density functional theory. Combining force and tunneling spectroscopy, we find that a strong charge transfer induces an inward dipole moment at the cyclo-P5/Ag interface as well as the formation of an interface state. We probe the image potential states by field-effect resonant tunneling and quantify the increase of the local change of work function of 0.46 eV at the cyclo-P5 assembly. Our experimental approach suggest that the cyclo-P5/Ag interface has the characteristic ingredients of a p-type semiconductor-metal Schottky junction with potential applications in field-effect transistors, diodes, or solar cells. Although unstable in nature, phosphorus pentamers (cyclo-P5) can be synthesized on a silver surface. Here, the authors use scanning probe microscopy to probe charge redistribution at the P5/Ag interface offering potential applications in transistors or solar cells. [ABSTRACT FROM AUTHOR]

Scanning probe microscopy (SPM) is a broad family of diagnostic methods. Common restraint of SPM is only surficial interaction with specimen, especially troublesome in case of complex volumetric systems, e.g. microbial or microelectronic. Scanning thermal microscopy (SThM) overcomes that constraint, since thermal information is collected from broader space. We present transformer bridge-based setup for resistive nanoprobe-based microscopy. With low-frequency (LF) (approx. 1 kHz) detection signal bridge resolution becomes independent on parasitic capacitances present in the measurement setup. We present characterisation of the setup and metrological description—with resolution of the system 0.6 mK with sensitivity as low as 5 mV K−1. Transformer bridge setup brings galvanic separation, enabling measurements in various environments, pursued for purposes of molecular biology. We present results SThM measurement results of high-thermal contrast sample of carbon fibres in an epoxy resin. Finally, we analyse influence of thermal imaging on topography imaging in terms of information channel capacity. We state that transformer bridge-based SThM system is a fully functional design along with low driving frequencies and resistive thermal nanoprobes by Kelvin Nanotechnology. [ABSTRACT FROM AUTHOR]

This report is on magneto-electric (ME) interactions in bulk composites with coaxial fibers of nickel–zinc ferrite and PZT. The core–shell fibers of PZT and Ni1−xZnxFe2O4 (NZFO) with x = 0–0.5 were made by electrospinning. Both kinds of fibers, either with ferrite or PZT core and with diameters in the range of 1–3 μm were made. Electron and scanning probe microscopy images indicated well-formed fibers with uniform core and shell structures and defect-free interface. X-ray diffraction data for the fibers annealed at 700–900 °C did not show any impurity phases. Magnetization, magnetostriction, ferromagnetic resonance, and polarization P versus electric field E measurements confirmed the ferroic nature of the fibers. For ME measurements, the fibers were pressed into disks and rectangular platelets and then annealed at 900–1000 °C for densification. The strengths of strain-mediated ME coupling were measured by the H-induced changes in remnant polarization Pr and by low-frequency ME voltage coefficient (MEVC). The fractional change in Pr under H increased in magnitude, from +3% for disks of NFO–PZT to −82% for NZFO (x = 0.3)-PZT, and a further increase in x resulted in a decrease to a value of −3% for x = 0.5. The low-frequency MEVC measured in disks of the core–shell fibers ranged from 6 mV/cm Oe to 37 mV/cm Oe. The fractional changes in Pr and the MEVC values were an order of magnitude higher than for bulk samples containing mixed fibers with a random distribution of NZFO and PZT. The bulk composites with coaxial fibers have the potential for use as magnetic field sensors and in energy-harvesting applications. [ABSTRACT FROM AUTHOR]

Controlling nanoscale tip‐induced material removal is crucial for achieving atomic‐level precision in tomographic sensing with atomic force microscopy (AFM). While advances have enabled volumetric probing of conductive features with nanometer accuracy in solid‐state devices, materials, and photovoltaics, limitations in spatial resolution and volumetric sensitivity persist. This work identifies and addresses in‐plane and vertical tip‐sample junction leakage as sources of parasitic contrast in tomographic AFM, hindering real‐space 3D reconstructions. Novel strategies are proposed to overcome these limitations. First, the contrast mechanisms analyzing nanosized conductive features are explored when confining current collection purely to in‐plane transport, thus allowing reconstruction with a reduction in the overestimation of the lateral dimensions. Furthermore, an adaptive tip‐sample biasing scheme is demonstrated for the mitigation of a class of artefacts induced by the high electric field inside the thin oxide when volumetrically reduced. This significantly enhances vertical sensitivity by approaching the intrinsic limits set by quantum tunneling processes, allowing detailed depth analysis in thin dielectrics. The effectiveness of these methods is showcased in tomographic reconstructions of conductive filaments in valence change memory, highlighting the potential for application in nanoelectronics devices and bulk materials and unlocking new limits for tomographic AFM. [ABSTRACT FROM AUTHOR]

Understanding the structure and function of bioelectric materials is challenging due to the complex nature of biomaterials and a lack of appropriate tools. The precisely defined structures and genetic tunability of viruses provide an excellent model system to investigate bioelectrical behavior in biomaterials. This study presents the molecular mechanisms of piezoelectricity in the M13 bacteriophage (phage) under various mechanical stresses for bio‐piezoelectric generation. A computational approach is used to calculate the piezoelectric tensors of the M13 phage and quantify its direction‐dependent dipole moments. By computationally designing negatively charged residues on the phage surface, the surface charge density is enhanced to 16.7 µC cm−2. Using genetic engineering, phages are experimentally designed with different charges and tail structures to create model phage nanostructures, including individual phages, vertically standing phage films, and horizontally aligned phage films. Their vertical, horizontal, and shear‐mode piezoelectric properties are then measured using scanning probe microscopy techniques. The resulting phage‐based piezoelectric energy generators exhibit an effective piezoelectric coefficient of 15.4 pm V−1 and a power density of 4.2 µW cm−2. This phage‐based bioengineering approach provides a versatile platform for investigating fundamental mechanisms of bioelectricity and designing bioelectric materials for applications in energy harvesting, biomemory, and biosensors. [ABSTRACT FROM AUTHOR]

Y 2 O 3 /AlN composite films with different thicknesses of AlN interlayer were prepared on CVD diamond by RF magnetron sputtering. The influence of AlN thickness on the microstructure, adhesion strength, film stress, thermal shock resistance and infrared transmittance of the films was investigated by X-ray diffractometer, scanning electron microscopy, scanning probe microscopy, UV–Vis spectrophotometer, Fourier transform infrared spectrometer, scratch tester and 3-D optical surface profiler. The results show that CVD diamond coated with Y 2 O 3 /AlN composite films with different thicknesses of AlN have different degrees of anti-reflective effects in the 8–10 μm infrared band. The adhesion strength and quality of the composite film were improved with the AlN thickness increased, and the anti-reflective and anti-thermal shock of the film showed a trend of first increasing and then decreasing. CVD diamond coated with Y 2 O 3 /AlN composite films with 700 nm AlN interlayer has an average transmittance of 77 % in the 8–10 μm band and a good adhesion between interfaces. It can withstand rapid temperature changes and effectively protect the diamond substrate with little or no degradation of infrared optical properties. [ABSTRACT FROM AUTHOR]

An unusual self‐assembly pattern is observed for highly ordered 1500‐nm‐thick films of monodisperse 13‐nm‐sized colloidal PbSe quantum dots, originating from their faceted truncated cube‐like shape. Specifically, self‐assembled PbSe dots exhibited attachment to the substrate by <001> planes followed by an interconnection through the {001} facets in plan‐view and {110}/{111} facets in cross‐sectional‐view, thus forming a cubic superlattice. The thermoelectric properties of the PbSe superlattice thin films are investigated by means of frequency domain thermoreflectance, scanning thermal probe microscopy, and four‐probe measurements, and augmented by computational efforts. Thermal conductivity of the superlattice films is measured as low as 0.7 W m−1 K−1 at room temperature due to the developed nanostructure. The low values of electrical conductivity are attributed to the presence of insulating oleate capping ligands at the dots’ surface and the small contact area between the PbSe dots within the superlattice. Experimental efforts aiming at the removal of the oleate ligands are conducted by annealing or molten‐salt treatment, and in the latter case, yielded a promising improvement by two orders of magnitude in thermoelectric performance. The result indicates that the straightforward molten‐salt treatment is an interesting approach to derive thermoelectric dot superlattice thin films over a centimeter‐sized area. [ABSTRACT FROM AUTHOR]

Organic–inorganic 2D heterostructures combine the high optical absorption of organic molecules with exciton‐dominated optical properties in layered transition metal dichalcogenides (TMDs) such as MoS2. Critical to the interaction and the optical response in such hybrid systems is the electronic band alignment at the interface between the two species. Here, the coupling of monolayers of perylene derivatives is investigated with bilayer MoS2. In particular, variation in the perylene orientation on the MoS2 surface is identified using Raman spectroscopy and scanning probe microscopy. Low‐temperature optical spectroscopy reveals orientation‐dependent interlayer exciton formation. Furthermore, power‐dependent photoluminescence measurements provide insight into the modified interlayer charge transfer in these heterostructures. A saturation of interlayer states is found under high excitation power when the perylene molecules are in a perpendicular orientation to the surface that leads to electron accumulation in the MoS2, whereas parallel alignment of the perylene molecules leads to enhanced populations of organic–inorganic interlayer excitons. This work provides insights into the optimization of organic–inorganic heterostructures, with particular relevance to applications for optoelectronic and excitonic devices. [ABSTRACT FROM AUTHOR]

Single crystals of (001)‐oriented 0.7Pb(Mg1/3Nb2/3)−0.3PbTiO3 (PMN‐30PT) with a composition near the morphotropic phase boundary have attracted considerable attention due to their superior dielectric and electromechanical performance. Recently, a new alternating current (electric field) poling approach used for the enhancement of dielectric and piezoelectric properties. However, the microscopic domain variants that govern the performance, especially under high‐frequency alternating current (AC) voltages, remain largely unexplored. In this work, the domain microstructure under AC poling reveals the presence of four monoclinic (MA) domain variants using a suite of scanning probe microscopy methods, and X‐ray diffraction (XRD) reciprocal space mapping is tuned. It is reported on the emergence of hierarchical fine domains – needle‐shaped, and 109° domain walls under applied high‐frequency AC poling. Time‐resolved Kelvin probe force microscopy (KPFM) reveals the charge dynamics and relaxation behavior of these needle domains and walls. The findings provide new insight and guidance to the domain engineering by high‐frequency AC poling for the development of advanced transducer technology. [ABSTRACT FROM AUTHOR]

We introduce a novel rotational stage based on inertial motion, designed to be lightweight, compact, and fully compatible with atomic force microscopy (AFM) systems. Our characterization of this stage demonstrates high angular precision, achieving a maximum rotational speed of 0.083 rad/s and a minimum angular step of 11.8 μrad. The stage exhibits reliable performance, maintaining continuous operation for extended periods. When tested within an AFM setup, the stage deliveres excellent results, confirming its efficacy for scanning probe microscopy studies. [ABSTRACT FROM AUTHOR]

Material-by-design has been a long-standing aspiration that has recently become a reality. Such designer materials have been repeatedly demonstrated using the top-down approach of mechanical exfoliation and stacking, leading to a variety of artificial 2D heterostructures with new properties that are otherwise unattainable. Consequently, tremendous research frontiers in physics, chemistry, engineering, and life science have been created. While thousands of layered crystals exist in nature, only a few dozen of them with manageable chemical-stability have been made into heterostructures using this method. Moreover, experimental investigations of materials that have received limited exploration in the 2D realm, such as cuprates, halides, and perovskites, along with their heterostructures, have been fundamentally hindered by their rapid chemical degradation. Another critical challenge imposed by exfoliating and stacking 2D layers in ambient environment is the absorption of itinerant gas molecules that further contaminate sensitive 2D interfaces in the heterostructures. Such contamination and compromised material properties significantly hinder surface-sensitive local probes—scanning probe microscopy (SPM)—that often require nanometer to atomic scale surface cleanliness. In this article, we aim to provide a technical review of recent development toward 2D materials and heterostructure fabrication in more controlled environments that are suitable for SPM characterizations. These include the development of more efficient mechanical exfoliation and dry-transfer techniques, as well as the incorporation of 2D material exfoliation and transfer in inert gas, low vacuum, and, eventually, ultra-high vacuum environments. Finally, we provide an outlook on the remaining challenges and opportunities in ultra-clean 2D material fabrication techniques. [ABSTRACT FROM AUTHOR]

Cantilever-free scanning probe microscopy has enormous potential for high-throughput topography imaging using parallel probe arrays. However, the current imaging mechanism of the cantilever-free tip architecture hardly considers the efficiency of the detection method regarding precision and bandwidth, which could be a bottleneck to expanding the application of this measurement system. In this communication, we present a contact resistance-based cantilever-free imaging system using radio frequency (RF) reflectometry. RF reflectometry measurements provide sensitive detection of the contact resistance with a wide bandwidth, enabling sub-micrometer-scale topography imaging. We demonstrated our imaging system using a carbon black-polydimethylsiloxane composite tip with a custom-built RF reflectometry setup. The proof-of-concept system achieved a resolution of 230 nm and a bandwidth of the detection system of approximately 8.5 MHz, validating the feasibility of the imaging technique for potential high-throughput cantilever-free scanning probe microscopy. [ABSTRACT FROM AUTHOR]

In contact mode scanning probe microscopy (SPM), the microcantilever probe's dynamics are governed by the (short-range) surface interaction forces, where the tip is "always-in-contact" with the sample. In intermittent contact modes such as "tapping" or bimodal SPM, on the other hand, these are governed by the frequency of the microcantilever's own external excitation. However, when contact mode is employed with high scan speeds (for "video-rate" SPM), we see intermittent transitions—within a single oscillation cycle—between the "always-in-contact" regime and another which is dominated by the microcantilever's inertia. We find—through experiments and physical modeling—that the fast in-plane motion of the sample relative to the probe results in a high surface excitation frequency v / λ (and its harmonics), which excite the microcantilever's out-of-plane eigenmodes and cause it to "break free" of the surface and "overshoot" and "parachute." The impacts of the tip that consequently occur upon the sample inject energy over a wide frequency band into the higher eigenmodes, especially when operating in a low dissipation ambient environment. The microcantilever, then, exhibits phenomena such as eigenmode switching, sidebands, and fractional and combination resonances; such behavior is not seen in, say, tapping mode SPM, since, there, energy is injected at an externally-determined temporal rate. This article investigates the transition from the dynamics of the microcantilever at low speeds to that exhibited at high speeds. The model for dynamic contact loss is validated against the experiments and can be used to propose mitigation of such dynamics in order to achieve high-resolution imaging. [ABSTRACT FROM AUTHOR]

The comparative analysis of the structural, morphological, and local electrical properties of CVD graphene films synthesized at atmospheric and low pressure CVD growth conditions was carried out. The use of electrical techniques of scanning probe microscopy, such as Kelvin probe force microscopy, scanning capacitance microscopy, electrostatic force microscopy, and conductive atomic-force microscopy for investigation of heterogeneous graphene coverage was discussed. A significant change in the surface potential values was observed indicating the formation of p-type multilayered graphene domains on single layer graphene at low pressure and n-type multilayered graphene films at atmospheric pressure CVD. The effect of Ar flow rate increasing during cooling stage in the temperature range of 700–200 °C causing graphite formation was described. The employment of surface potential spectroscopy allows to indicate the presence of nonlinear phenomena in heterogeneous graphene. [ABSTRACT FROM AUTHOR]

During the past decade, Scanning Probe Microscopy (SPM) based surface strain detection techniques have been extensively used in the characterization of functional materials, structures, and devices. Here, we refer these techniques as Surface Strain Force Microscopy (SSFM), which mainly includes the Piezoresponse Force Microscopy, Atomic Force Acoustic Microscopy, Atomic Force Microscopy-Infrared spectroscopy (or photothermal induced resonance), Piezomagnetic Force Microscopy, and Scanning Joule Expansion Microscopy. The inception of SSFM opens up a pathway to study the nanoscale physical properties by using a sharp tip to detect the local field-induced surface strain. Through measuring the signals of the surface strain, multiple physical properties, such as the electromechanical, mechanical, photothermal, magnetic, thermoelastic properties, can be characterized with an unprecedented spatial resolution. In order to further develop and overcome the fundamental issues and limitations of the SSFM, the multi-frequency SPM technology has been introduced to the SSFM-based techniques, leading to the emerging of multi-frequency SSFM (MF-SSFM). As a technical breakthrough of the SSFM, MF-SSFM has demonstrated substantial improvements in both performance and capability, resulting in increased attentions and numerous developments in recent years. This Perspective is, therefore, aimed at providing a preliminary summary and systematic understanding for the emerging MF-SSFM technology. We will first introduce the basic principles of conventional SSFM and multi-frequency SPM techniques, followed by a detailed discussion about the existing MF-SSFM techniques. MF-SSFM will play an increasingly important role in future nanoscale characterization of the physical properties. As a result, many more advanced and complex MF-SSFM systems are expected in the coming years. [ABSTRACT FROM AUTHOR]

Li[Ni0.885Co0.1V0.015]O2 (NCV), Li[Ni0.9Co0.1]O2 (NC), and Li[Ni0.885Co0.1Al0.015]O2 (NCA) nanoparticles are synthesized by means of oxalic acid co-precipitation with subsequent calcination. The evolution of Li-ion diffusion and deformation of both NCV and NCA under an external electric field are characterized by means of conductive atomic force microscopy and electrochemical strain microscopy. Macroscopic electrochemical characterization reveals that the Li-ion diffusivity in NCA is greater than that in NCV, and the undesirable irreversible H2–H3 phase transition occurs more readily in NCV than in NCA. The scanning probe microscopy results corroborate well with the macroscopic electrochemical measurements, which tell that vanadium and aluminum substitution can accelerate Li+ diffusion kinetics and enhance the reversibility of the H2–H3 phase transformation during the electrochemical process in varying degrees. [ABSTRACT FROM AUTHOR]

We introduce a new scanning probe microscopy (SPM) concept called reverse tip sample scanning probe microscopy (RTS SPM), where the tip and sample positions are reversed as compared to traditional SPM. The main benefit of RTS SPM over the standard SPM configuration is that it allows for simple and fast tip changes. This overcomes two major limitations of SPM which are slow data acquisition and a strong dependency of the data on the tip condition. A probe chip with thousands of sharp integrated tips is the basis of our concept. We have developed a nanofabrication protocol for Si based probe chips and their functionalization with metal and diamond coatings, evaluated our probe chips for various RTS SPM applications (multi-tip imaging, SPM tomography, and correlative SPM), and showed the high potential of the RTS SPM concept. [ABSTRACT FROM AUTHOR]

We report on‐surface synthesis of heterochiral 1D heptahelicene oligomers after deposition of a racemic heptahelicene monomer on an Au(111) surface followed by Ullmann coupling under ultrahigh vacuum conditions. Structure, chirality and mode of adsorption of the resulting dimers to octamers are inferred from the scanning probe microscopy and theoretical calculations. [ABSTRACT FROM AUTHOR]

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Van der Waals heterostructures have opened new opportunities to develop atomically thin (opto)electronic devices with a wide range of functionalities. The recent focus on manipulating the interlayer twist angle has led to the observation of out-of-plane room temperature ferroelectricity in twisted rhombohedral bilayers of transition metal dichalcogenides. Here we explore the switching behaviour of sliding ferroelectricity using scanning probe microscopy domain mapping and tunnelling transport measurements. We observe well-pronounced ambipolar switching behaviour in ferroelectric tunnelling junctions with composite ferroelectric/non-polar insulator barriers and support our experimental results with complementary theoretical modelling. Furthermore, we show that the switching behaviour is strongly influenced by the underlying domain structure, allowing the fabrication of diverse ferroelectric tunnelling junction devices with various functionalities. We show that to observe the polarisation reversal, at least one partial dislocation must be present in the device area. This behaviour is drastically different from that of conventional ferroelectric materials, and its understanding is an important milestone for the future development of optoelectronic devices based on sliding ferroelectricity. The authors study tunneling junctions in rhombohedral MoS2 bilayers and correlate their performance with the local domain layout. They show that the switching behavior in sliding ferroelectrics is strongly dependent on the pre-existing domain structure. [ABSTRACT FROM AUTHOR]

Surface chemistry significantly influences the physicochemical and functional properties of nanoparticles, thus necessitating the investigation of surfaces, especially when subjected to chemisorption. Seeking a method that delivers both high‐resolution imaging and precise chemical information, tip‐enhanced Raman spectroscopy (TERS) emerges as a critical technique. By the combination of scanning probe microscopy with Raman spectroscopy, TERS effectively addresses the limitations of traditional optical microscopes in the study of nanoparticles. The results provide detailed nanoscale structural insights, shed light on surface chemistry, and enable the detection of Raman‐forbidden modes caused by the substantial electric field at the tip apex (≈3 × 108 V m−1). This electric field plays a crucial role in altering selection rules, thereby broadening the scope of TERS beyond merely detecting Raman modes. By combining topographical with TERS mapping, the presence of a carbonate monolayer on the barium titanate (BaTiO3) nanoparticle surface is unveiled – an observation elusive to common characterization techniques. [ABSTRACT FROM AUTHOR]

2D materials are intriguing due to their remarkably thin and flat structure. This unique configuration allows the majority of their constituent atoms to be accessible on the surface, facilitating easier electron tunneling while generating weak surface forces. To decipher the subtle signals inherent in these materials, the application of techniques that offer atomic resolution (horizontal) and sub‐Angstrom (z‐height vertical) sensitivity is crucial. Scanning probe microscopy (SPM) emerges as the quintessential tool in this regard, owing to its atomic‐level spatial precision, ability to detect unitary charges, responsiveness to pico‐newton‐scale forces, and capability to discern pico‐ampere currents. Furthermore, the versatility of SPM to operate under varying environmental conditions, such as different temperatures and in the presence of various gases or liquids, opens up the possibility of studying the stability and reactivity of 2D materials in situ. The characteristic flatness, surface accessibility, ultra‐thinness, and weak signal strengths of 2D materials align perfectly with the capabilities of SPM technologies, enabling researchers to uncover the nuanced behaviors and properties of these advanced materials at the nanoscale and even the atomic scale. [ABSTRACT FROM AUTHOR]

The multifaceted physics of oxides is shaped by their composition and the presence of defects, which are often accompanied by the formation of polarons. The simultaneous presence of polarons and defects, and their complex interactions, pose challenges for first-principles simulations and experimental techniques. In this study, we leverage machine learning and a first-principles database to analyze the distribution of surface oxygen vacancies (VO) and induced small polarons on rutile TiO2(110), effectively disentangling the interactions between polarons and defects. By combining neural-network supervised learning and simulated annealing, we elucidate the inhomogeneous VO distribution observed in scanning probe microscopy (SPM). Our approach allows us to understand and predict defective surface patterns at enhanced length scales, identifying the specific role of individual types of defects. Specifically, surface-polaron-stabilizing VO-configurations are identified, which could have consequences for surface reactivity. [ABSTRACT FROM AUTHOR]

In this study, a Y2O3 insulator was fabricated via the sol–gel process and the effect of precursors and annealing processes on its electrical performance was studied. Yttrium(III) acetate hydrate, yttrium(III) nitrate tetrahydrate, yttrium isopropoxide oxide, and yttrium(III) tris (isopropoxide) were used as precursors, and UV/ozone treatment and high-temperature annealing were performed to obtain Y2O3 films from the precursors. The structure and surface morphologies of the films were characterized via grazing-incidence X-ray diffraction and scanning probe microscopy. Chemical component analysis was performed via X-ray spectroscopy. Electrical insulator characteristics were analyzed based on current density versus electrical field data and frequency-dependent dielectric constants. The Y2O3 films fabricated using the acetate precursor and subjected to the UV/ozone treatment showed a uniform and flat surface morphology with the lowest number of oxygen vacancy defects and unwanted byproducts. The corresponding fabricated capacitors showed the lowest current density (Jg) value of 10−8 A/cm2 at 1 MV/cm and a stable dielectric constant in a frequency range of 20 Hz–100 KHz. At 20 Hz, the dielectric constant was 12.28, which decreased to 10.5 at 105 Hz. The results indicate that high-quality, high-k insulators can be fabricated for flexible electronics using suitable precursors and the suggested low-temperature fabrication methods. [ABSTRACT FROM AUTHOR]

The article discusses the application of scanning thermal microscopy (SThM) for localizing and monitoring defects in electronics, emphasizing its role in thermal management, defect detection, and performance improvement of microelectronic technologies. It introduces the principle of SThM instruments, describes their operation in passive and active modes, and highlights their capabilities in detecting localized inhomogeneities and overheating in electronic components.

Highly hydrophilic and antifouling poly(vinylidene fluoride) (PVDF) ultrafiltration membranes are developed with excellent permeation using a zirconium‐based metal–organic framework (MOF‐801). MOF‐801 is synthesized by a solvothermal method using zirconium(IV) oxychloride octahydrate (ZrOCl2⋅8H2O) and fumaric acid. The chemical functionality of MOF‐801 is studied by Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD) whereas surface morphology and elemental composition are probed by scanning electron microscopy (SEM)/energy‐dispersive X‐ray analysis (EDX). The PVDF/MOF‐801 membranes are characterized in terms of FTIR, XRD, FESEM/EDX and atomic force microscopy. The performance of the hybrid PVDF/MOF‐801 membranes in terms of pure water flux and antifouling ability is found to be improved compared with bare PVDF membranes. The wettability of the membranes is measured by water contact angle and found to be 76.7° for bare PVDF membrane, which decreases upon the addition of MOF‐801 to 55.1° due to the increase in surface hydrophilicity. A notable increase in roughness of 226.29 nm and a porosity of 67.91% is observed for the addition of 2 wt% MOF‐801 in PVDF membrane matrix. The flux recovery ratio of the hybrid membrane is increased from 66.4% to 89.6% and from 68.3% to 85.2% for bovine serum albumin (BSA) and humic acid (HA) separation, respectively. In addition, the reversible and irreversible fouling performance during the rejection of BSA (93%) and HA (88%) indicates the enhanced antifouling property of the PVDF/MOF‐801 membranes. A zone of inhibition test evidences the outstanding antibiofouling activity of the PVDF/MOF‐801 membranes against E. coli and S. aureus. Overall results demonstrated the suitability of hybrid PVDF/MOF‐801 membranes for water and wastewater treatment. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells, which require high-quality single crystals with controlled defect levels. Herein, we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates (MPs), and reported a defect-modulated photocurrent which is closely related to the growth sequence of the MPs. The MP synthesis initiates from island-like nano-disks, and subsequently transits to a layer-by-layer fashion, resulting in a defect-rich area at the center of the MPs. At elevated temperatures, these central defects may be thermally activated and become highly mobile, leading to photoluminescence quenching and degression of local and overall optoelectronic attributes, as evidenced by the spatial resolved optical and electrical scanning probe microscopy. Overall, this work shines light on the formation, proliferation and dynamics of defects in perovskites, and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability. [ABSTRACT FROM AUTHOR]

A method for patterning single‐layer graphene (SLG) and single‐layer oxidized graphene (SOG) within a continuous atomic layer to form lateral heterojunctions is presented. Raman spectroscopy is employed to investigate the evolution of defect‐related Raman peaks during excimer‐UV irradiation, facilitating the identification of structural changes and defect formation processes. Electrical transport measurements reveal that SOG‐patterned field‐effect transistors (FETs) exhibit varying characteristics depending on the degree of oxidation, thus offering the potential to tailor the electrical properties of graphene devices for specific requirements. Scanning Kelvin probe microscopy measurements reveal the surface potential and work function of the SOG regions compared with those of SLG. The effective functionality of the SOG pattern to operate as a resistor, allowing control of the electrical conductivity in the SOG‐patterned SLG channels, is demonstrated. This capability restricts the current flow while preserving the pristine electrical properties of the graphene channel. Moreover, the SOG pattern can serve as a potential barrier to constructing SLG‐SOG‐patterned integrated circuits, providing exciting opportunities for engineering advanced electronic components. This breakthrough in graphene devices simplifies the fabrication process of graphene‐based FETs and provides the foundation for developing atomically thin integrated circuits for a wide range of applications. [ABSTRACT FROM AUTHOR]

BiFeO3 is a rare single‐phase multiferroic which shows coupled ferroelectricity, ferroelasticity and antiferromagnetism at room temperature. Many fantastic properties of BiFeO3 are regulated by its domain structure. While (001) rhombohedral BiFeO3 thin films can possibly develop up‐to eight degenerate states of two‐variant 71° ferroelastic domain stripes, complete selective control of all possible switching paths between these states has not yet been achieved. Here, combining phase field simulations and scanning probe microscopy experiments, we demonstrated such a complete selective control. The tip bias and the built‐in field were shown to affect the volume fraction of the 71°, 109° and 180° switched domains in rhombohedral BiFeO3 thin films under single‐point loading. Meanwhile, tip scanning further broke the symmetry of the nucleated domains, leading to different switched domain patterns. We then grew BiFeO3 thin films with a specific two‐variant 71° ferroelastic domain state and showed that such a state could be deterministically switched into the other seven two‐variant domain states by collaborative controlling tip scanning and tip bias in scanning probe microscopy experiments. These results should deepen our current understanding on the domain switching kinetics in BiFeO3 thin films and indicate they are promising platforms for developing configurable electronic and spintronic devices. [ABSTRACT FROM AUTHOR]

The local imaging technique, which is able to directly visualize the catalytic activity originating from the structural heterogeneity of the catalyst, is significantly required to provide the guidelines for the development of the new catalyst with an ability of efficient activity. Scanning electrochemical cell microscopy (SECCM) is one of the promising candidates because of the ability to obtain the distribution of redox activity on the sub-microscale by forming the meniscus on the sample surface using a nanopipette. We have so far developed single-barrel SECCM to further improve its spatial resolution. In addition, we have applied this technique to various catalysts, for instance, MoS2 and SnS2 nanosheets and TiO2 nanotube. Here, we present the principle and setup of single-barrel SECCM and its applications to the chemistry of catalysis. [ABSTRACT FROM AUTHOR]

Detecting ferroelectricity at micro- and nanoscales is crucial for advanced nanomaterials and materials with complicated topography. Switching spectroscopy piezoresponse force microscopy (SSPFM), which involves measuring piezoelectric hysteresis loops via a scanning probe microscopy tip, is a widely accepted approach to characterize polarization reversal at the local scale and confirm ferroelectricity. However, the local hysteresis loops acquired through this method often exhibit unpredictable shapes, a phenomenon often attributed to the influence of parasitic factors such as electrostatic forces and current flow. Our research has uncovered that the deviation in hysteresis loop shapes can be caused by spontaneous backswitching occurring after polarization reversal. Moreover, we've determined that the extent of this effect can be exacerbated when employing inappropriate SSPFM waveform parameters, including duration, frequency, and AC voltage amplitude. Notably, the conventional 'pulse-mode' SSPFM method has been found to intensify spontaneous backswitching. In response to these challenges, we have redesigned SSPFM approach by introducing the positive up-negative down (PUND) method within the 'step-mode' SSPFM. This modification allows for effective probing of local piezoelectric hysteresis loops in ferroelectrics with reversible piezoresponse while removing undesirable electrostatic contribution. This advancement extends the applicability of the technique to a diverse range of ferroelectrics, including semiconductor ferroelectrics and relaxors, promising a more reliable and accurate characterization of their properties. [ABSTRACT FROM AUTHOR]

Microscopy has been pivotal in improving the understanding of structure‐function relationships at the nanoscale and is by now ubiquitous in most characterization labs. However, traditional microscopy operations are still limited largely by a human‐centric click‐and‐go paradigm utilizing vendor‐provided software, which limits the scope, utility, efficiency, effectiveness, and at times reproducibility of microscopy experiments. Here, a coupled software–hardware platform is developed that consists of a software package termed AEcroscopy (short for Automated Experiments in Microscopy), along with a field‐programmable‐gate‐array device with LabView‐built customized acquisition scripts, which overcome these limitations and provide the necessary abstractions toward full automation of microscopy platforms. The platform works across multiple vendor devices on scanning probe microscopes and electron microscopes. It enables customized scan trajectories, processing functions that can be triggered locally or remotely on processing servers, user‐defined excitation waveforms, standardization of data models, and completely seamless operation through simple Python commands to enable a plethora of microscopy experiments to be performed in a reproducible, automated manner. This platform can be readily coupled with existing machine‐learning libraries and simulations, to provide automated decision‐making and active theory‐experiment optimization to turn microscopes from characterization tools to instruments capable of autonomous model refinement and physics discovery. [ABSTRACT FROM AUTHOR]

Surface/interface engineering of methylammonium lead bromide (MAPbBr3) single crystals (SCs) is crucial for carrier generation/recombination, separation, and transportation, thereby enabling superior optoelectronics. Herein, a surface‐engineered crystallization technique is presented in which a thin polycrystalline MAPbBr3 layer is in situ grown on the surface of bulk mm‐sized MAPbBr3 SCs. The growth direction and the atomic distribution of both the polycrystalline surface layer and the single crystalline core have been analyzed by damage‐free atomic‐resolution transmission electron microscopy (TEM). The polycrystalline nature of the crystals gives rise to bright green emission under UV light. Scanning probe microscopy results show that the current at the emissive MAPbBr3 film/MAPbBr3 SC surface is five times higher than that at a non‐emissive surface when illuminated. Lateral photodetectors based on MAPbBr3 film/MAPbBr3 SCs can achieve excellent detectivities (≈1013 Jones) and high photoresponsivities (≈20 A W−1). Furthermore, a semiconductor‐based fluorescence quick response (FQR) code is patterned on the same bright green‐emitting surface of the MAPbBr3 film/MAPbBr3 SC using a picosecond laser pulse, with a scalability of 3 × 3 mm2. An FQR code integrated with a photodetector may serve as a potential double security tag in bank cards, passports, door security, etc. [ABSTRACT FROM AUTHOR]

Strained macrocycles display interesting properties, such as conformational rigidity, often resulting in enhanced π‐conjugation or enhanced affinity for non‐covalent guest binding, yet they can be difficult to synthesize. Here we use computational modeling to design a template to direct the formation of an 18‐porphyrin nanoring with direct meso‐meso bonds between the porphyrin units. Coupling of a linear 18‐porphyrin oligomer in the presence of this template gives the target nanoring, together with an unexpected 36‐porphyrin ring by‐product. Scanning tunneling microscopy (STM) revealed the elliptical conformations and flexibility of these nanorings on a Au(111) surface. [ABSTRACT FROM AUTHOR]

Photoresponsive supramolecular polymers have a major potential for applications in responsive materials that are externally triggered by light with spatio‐temporal control of their polymerisation state. While changes in macroscopic properties revealed the adaptive nature of these materials, it remains challenging to capture the dynamic depolymerisation process at the molecular level, which requires fast observation techniques combined with in situ irradiation. By implementing in situ UV illumination into a High‐Speed Atomic Force Microscope (HS‐AFM) setup, we have been able to capture the disassembly of a light‐driven molecular motor‐based supramolecular polymer. The real‐time visualisation of the light‐triggered disassembly process not only reveals cooperative depolymerisation, it also shows that this process continues after illumination is halted. Combining the data with cryo‐electron microscopy and spectroscopy approaches, we obtain a molecular‐level description of the motor‐based polymer dynamics reminiscent of actin chain‐end depolymerisation. Our detailed understanding of supramolecular depolymerisation will drive the development of future responsive polymer systems. [ABSTRACT FROM AUTHOR]

The development of new technologies for the current energy and environmental challenges requires the acquisition of a very fundamental knowledge about the structure and activity of catalytic materials at the nanometric scale. As a consequence, in situ and operando methodologies are blossoming, but only a fraction of them really aims at a local vision that would allow watching atoms at work during reactions. In this short report, we want to outline the merits of a new technique based on scanning tunnelling microscopy (Current-roughness electrochemical scanning tunneling microscopy, cr-EC-STM) which can visualize electrocatalytic reactions down at the single atom level. Results of two case studies in the field of hydrogen evolution reaction (HER) are briefly summarized, witnessing the capability of cr-EC-STM to provide critical information about the structure and catalytic performance of the active sites with atomic resolution. [ABSTRACT FROM AUTHOR]

Polyimide films with molecular imprints of erythrosine and indigocarmine have been obtained. The structure and morphology of the film surfaces have been studied by scanning probe microscopy and IR spectroscopy. It has been found that the surface roughness of molecularly imprinted polymers (MIPs) increases, while the relief height amounts to 3–4 nm. The removal of template molecules leads to a redistribution of pores over sizes in the polymers with molecular imprints. The adsorption of dyes by MIP films has been carried out under static conditions. The degrees of extraction and the imprinting factors have been calculated for polymers with molecular imprints of the dyes. The high values of these parameters indicate the selectivity of MIPs to the target template molecules. [ABSTRACT FROM AUTHOR]

Low-temperature scanning probe microscopes (SPMs) are critical for the study of quantum materials and quantum information science. Due to the rising costs of helium, cryogen-free cryostats have become increasingly desirable. However, they typically suffer from comparatively worse vibrations than cryogen-based systems, necessitating the understanding and mitigation of vibrations for SPM applications. Here we demonstrate the construction of two cryogen-free dilution refrigerator SPMs with minimal modifications to the factory default and we systematically characterize their vibrational performance. We measure the absolute vibrations at the microscope stage with geophones and use both microwave impedance microscopy and a scanning single-electron transistor to independently measure tip-sample vibrations. Additionally, we implement customized filtering and thermal anchoring schemes and characterize the cooling power at the scanning stage and the tip electron temperature. This work serves as a reference to researchers interested in cryogen-free SPMs, as such characterization is not standardized in the literature or available from manufacturers. [ABSTRACT FROM AUTHOR]