In this thematic issue, we present state-of-the-art research on non-contact atomic force microscopy (nc-AFM) with a focus on high resolution, the development of advanced scanning and spectroscopy techniques, simulation and theoretical modeling of the tip–sample interactions, as well as the application of nc-AFM to new materials.
Potential contributions are expected to be focused on the following topics:
- Novel instrumentation and techniques in AFM
- Atomic-resolution imaging on insulating substrates, semiconductors, and metals
- High-resolution imaging of molecules, clusters and biological systems
- Atomic- and molecular-scale manipulation
- Simultaneous force and tunneling current spectroscopy
- High-resolution imaging and spectroscopy in liquid environments
- Theoretical analysis of contrast mechanisms, forces and tunneling phenomena
- 2D and 3D force-field mapping
- Small amplitude and lateral force measurements using dynamic methods
- Mechanisms and understanding of damping and energy dissipation
- Nanoscale measurements of charges, work function, and magnetic properties
- Theoretical aspects of scanning probe techniques
Figure 1: (a) Scanning electron microscopy image of a sensor realization consisting of a silicon microcantile...
Figure 2: Calculated microcantilever amplitude response curve of the co-resonantly coupled system based on th...
Figure 3: (a) Resonance amplitudes of both resonance peaks of the coupled system calculated for the microcant...
Figure 4:
This diagram represents the necessary calculation steps to determine the effective spring constant ...
Figure 5: Effective spring constants for both resonance peaks of the coupled system in dependence on the eige...
Figure 6: Effective quality factor for both resonance peaks of the coupled system in dependence on the eigenf...
Figure 7: Qualitative behaviour of the effective quality factor for both resonance peaks of the coupled syste...
Figure 1: Adsorption of N2O molecules on the Au(111) substrate. (a) Overview STM image (100 mV, 10 pA, 50 × 5...
Figure 2: Tip functionalization with a N2O molecule. (a) STM image (100 mV, 10 pA, 6 × 6 nm2) demonstrating a...
Figure 3: Comparison of the calculated electrostatic potential projections of the CO (a) and N2O (b) tips obt...
Figure 4: Constant-current STM images of the co-adsorption of FePc and N2O molecules on a Au(111) surface (20...
Figure 5: (a) STM and AFM constant-height images of the FePc on Au(111) (1.7 × 1.7 nm2, Vb = 3 mV) obtained w...
Figure 1: Illustration of ionic transport measurements in the time domain. (a) A conducting AFM tip is brough...
Figure 2: (a) AFM frequency shift response to stretched-exponential voltage pulses (from 0 to 5 V) with and w...
Figure 3: (a) Schematic illustration of the voltage-pulse averaging EFM technique: the top shows the applied ...
Figure 4: Measured tip–sample force as a function of the distance for a gold-coated tip over a grounded gold ...
Figure 5: “(a) Schematic of the experimental setup: (i) Computer requests a trigger at a defined phase of the...
Figure 6: Extracted FF-trEFM signals from numerical simulations of tip–sample interactions with a stretched-e...
Figure 7: “(a) Calibration curve for a range of characteristic times of exponential decay (τ) (inset shows a ...
Figure 8: “For three representative pulse times, we plot (A) cantilever amplitude; (B) cantilever drive volta...
Figure 9: “Experiments and simulations demonstrating subcycle time resolution in pk-EFM. (A) Subcycle voltage...
Figure 10: Synthetic data of cantilever deflection spectrum around the fundamental resonance frequency, ω0 =2π...
Figure 11: “Results from simulations and from the experimental validation for the proposed excitation schemes:...
Figure 1: (a) Principle of n- and p-type DSSCs showing opposite charge transfer directions. (b) Structures of...
Figure 2: The surface of NiO(001). (a) Large-scale topographic image of the NiO(001) crystal showing clean te...
Figure 3: (a) Large-scale topographic image showing that Cu-TCPP molecules form islands on the surface of NiO...
Figure 4: (a) Large-scale topographic image showing that C343 molecules form islands on the surface of NiO(00...
Figure 5: (a, b) CPD measurements of Cu-TCCP and C343 islands on the NiO(001) substrate, respectively (scan p...
Figure 1: Phase shift as a function of the tip–substrate distance z; calculated for a silicon substrate with V...
Figure 2: Substrate without dielectric layer and with dielectric layer. The dielectric layer allows the tip t...
Figure 3: Phase shift due to capacitive coupling as a function of the lift height for nanoparticles with 10 n...
Figure 4: a) Sketch of a MFM measurement of a dielectric layer with defined roughness (Rmax); b) Simulation f...
Figure 5: Schematic representation of the distance between tip and nanoparticle dipole during the interleave ...
Figure 6: Simulation of the MFM phase for a single SPION using a Gaussian topographic profile corresponding t...
Figure 7: Phase shift above nanoparticles (10 ± 2 nm) on dielectric layers of various thicknesses as a functi...
Figure 8:
Calculated (; black line) and measured phase shift for single nanoparticles with 10 ± 2 nm diameter...
Figure 9: Measurement of a single SPION with 10 ± 2 nm diameter on a silicon substrate with a dielectric laye...
Figure 10: Measurement of a single SPION with 12 ± 1 nm diameter on a silicon substrate recorded with an ASYMF...
Figure 1: SEM images of an oriented network of titanium monoxide (TiO) nanowires on SrTiO3(100). In between t...
Figure 2: Electrical properties of TiO/SrTiO3(100) heterostructures. a), b) LC-AFM topography and current (Pt...
Figure 3: TiO facets influence the work function (WF) on the nanoscale. a) 3D view of the combined topography...
Figure 4: KPFM lateral resolution on high TiO/STO structures. a) Topography and b) work function of TiO nanow...
Figure 5: Characterization of the SrTiO3(100) surface by KPFM. a) Topography of a TiO/SrTiO3 structure (Δf = ...
Figure 6: Influence of air exposure on the TiO/SrTiO3 work function. a) KPFM topography and work function of ...
Figure 1: 1D schematic of the tip–sample convolution at islands and holes. Due to the tip geometry step edges...
Figure 2: 1.5 μm × 1.0μm sections showing the time evolution of artificial defects and accumulations in three...
Figure 3: Maximum depth of the observed holes over time. The poking holes to which the letters correspond is ...
Figure 4: 200 nm × 200 nm 3D profile image of the generated scratching site directly taken after generating, ...
Figure 5: Volume of the hole and accumulation at 3.0% < RH < 5.5% within seven days. No significant change in...
Figure 6: 250 nm × 250 nm images of the time evolution of both defect and accumulation at different consecuti...
Figure 7: Time evolution of both defect and accumulation volume. After an initial settling time the logarithm...
Figure 8: 200 nm × 200 nm sections of the time evolution of the scratching site at RH = 28.2%. Each image is ...
Figure 9: Time course of the size and change rate of the observed defect (upper position) and accumulation (l...
Figure 1: Batch fabrication process of LSNT-tip SU8 cantilevers. (a) Summarized process flow. (b) SEM image o...
Figure 2: Tip sharpness and durability assessment of the LSNT-tip SU8 cantilevers using a polycrystalline tit...
Figure 3: Comparison of the tapping bandwidth between our tip-integrated SU8 cantilever and a commercial sili...
Figure 1: (a) Schematic diagram of sample topography amplitude-modulating a cantilever the oscillation of whi...
Figure 2: Visualization of off-mode rejection in the frequency domain for a demodulator magnitude frequency r...
Figure 3: Functional block diagram of the multifrequency lock-in amplifier implementation. The zoom-box displ...
Figure 4: Functional block diagram of the multifrequency coherent demodulator implementation. The zoom-box di...
Figure 5: Functional block diagram of the Kalman filter implementation.
Figure 6: Functional block diagram of the multifrequency Lyapunov filter implementation. The zoom-box display...
Figure 7: Functional block diagram of the multifrequency direct-design filter implementation. The zoom-box di...
Figure 8: Experimental off-mode rejection results. Here each multifrequency demodulator is on a single row an...
Figure 9: Experimental amplitude estimation error and power spectral density of amplitude estimation for the ...
Figure 10: Higher-harmonic amplitude AFM imaging performed with the fundamental mode of a TAP190G cantilever o...
Figure 1: (a) Principle of pump–probe KPFM (pp-KPFM). In conventional KPFM, a sinusoidal ac voltage Vmod of f...
Figure 2: (a) Detail of the spectroscopic sequence implemented for the acquisition of the pp-KPFM signal as a...
Figure 3: (a) Top: chemical structures of PTB7 (electron donor, D) and PC71BM (electron acceptor, A). Bottom:...
Figure 4: (a, b) pp-KPFM single-point spectroscopy of an electrical square-wave signal of 10 µs (pump, amplit...
Figure 5: (a) Plot of the KPFM compensation potential measured at the solar cell cathode as a function of tim...
Figure 6: (a–f) Spectroscopic curves (average of 5 acquisitions) of the pp-KPFM compensation potential as a f...
Figure 7: (a) Topographic (nc-AFM, UHV, 300 K) and (b) KPFM compensation potential images (1 μm × 1 μm, 300 ×...
Figure 8: (a, c, e, g) nc-AFM/KPFM images of the PTB7:PC71BM blend (1 μm × 1 μm, 90 × 90 pixels) acquired dur...
Figure 9: pp-KPFM spectroscopic imaging of the PTB7:PC71BM blend in data-cube mode. Popt = 18.5 mW∙cm−2 (puls...
Figure 1: Structural models of rutile TiO2(110)-(1 × 2) reconstructed surface: (a) Symmetric Ti2O3 model [10] and...
Figure 2: (a) LEED pattern of rutile TiO2(110)-(1 × 2) reconstructed surface. The electron beam energy was 10...
Figure 3: (a) STM and (b) NC-AFM images of a rutile TiO2(110)-(1 × 2) reconstructed surface. (c, d) Height pr...
Figure 4: (a) High-resolution NC-AFM image of a rutile TiO2(110)-(1 × 2) reconstructed surface. The height pr...
Figure 5: Area exhibiting two types of asymmetric Ti2O3 rows. (a) High-resolution constant height mode NC-AFM...
Figure 1: Illustration of a tip trajectory with a perfect sinusoidal shape in the noncontact dynamic AFM mode...
Figure 2: Modified Bessel functions of the first kind of different orders. While the zeroth-order function ap...
Figure 3: Illustration of the intermittent-contact interaction case. The blue line represents ψ, the trajecto...
Figure 4: Illustration of the derivation of the indentation. The upper blue line represents the tip–sample di...
Figure 5: Normalised power spectrum of the current obtained for the noncontact, ideal-trajectory case. The bl...
Figure 6: a) Power spectrum of the cantilever trajectory. The higher harmonic amplitudes are very small compa...
Figure 7: Power spectrum of the current from analytical calculations and numerical cantilever simulations for...
Figure 8: a) Power spectrum of the tip trajectory for the realistic simulation with the Hertzian repulsive in...
Figure 9: Current output obtained from the intermittent-contact simulation (black trace) and reconstruction o...