Exploring surface charge dynamics: implications for AFM height measurements in 2D materials

• Mario Navarro-Rodriguez,
• Andres M. Somoza and
• Elisa Palacios-Lidon

Beilstein J. Nanotechnol. 2024, 15, 767–780, doi:10.3762/bjnano.15.64

• heterogeneous samples. This discrepancy arises from various sources depending on the operation mode and working parameters. In the frequency modulation mode (FM-AFM), a non-compensated bias voltage between tip and sample, from differences in the surface potential (SP), results in inaccurate height measurements

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• amplitude modulation AFM (AM-AFM) and frequency modulation AFM (FM-AFM). Both modes, and their many variants, rely on lock-in detection of the motion signal, and in most cases, this signal is at the same frequency as the excitation. Cavity optomechanical detection principles can be used for both AM-AFM and

• FM-AFM, as well as additional driving and read-out schemes. In contrast to optical cavities, superconducting lumped-element microwave resonators easily reach the resolved-sideband regime, where the cavity linewidth is smaller than the mechanical resonant frequency [1][15]. Typically, lumped-element

Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• account. In FM-AFM, it is impossible to perform a heterodyne-KPFM measurement by setting a “fixed” value for ω0. Dual-Heterodyne Kelvin Probe Force Microscopy: Principle To understand how dual-heterodyne KPFM works, consider the case of a sample subjected to a time-periodic pump that generates a (time

• ), driven by a Mimea scanning probe microscope (SPM) controller (SPECS-Nanonis). Topographic imaging is performed in FM mode (FM-AFM) in the attractive regime, with negative frequency shifts of a few Hz and vibration amplitudes of a few tens of nm. All experiments were performed with Pt/Ir coated silicon

High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• with respect to the cutoff frequency fc of carrier transport between the bulk and interface states and measuring the difference in CPD by KPFM. In high–low KPFM, frequency modulation (FM) KPFM (FM-KPFM) combined with FM-AFM is used to detect the tip–sample interaction force. FM-KPFM has several

• advantages, namely high sensitivity to the electrostatic force gradient, high detection sensitivity using a cantilever with a weak spring constant at the first resonance, ease of implementation in adding FM-AFM, and no need to enhance the bandwidth of the cantilever deflection sensor. FM-KPFM is used to

Two dynamic modes to streamline challenging atomic force microscopy measurements

• Alexei G. Temiryazev,
• Andrey V. Krayev and
• Marina P. Temiryazeva

Beilstein J. Nanotechnol. 2021, 12, 1226–1236, doi:10.3762/bjnano.12.90

• common feature is amplitude feedback. An alternative method uses the resonant frequency of the probe as a feedback parameter and is called frequency modulation AFM (FM-AFM). Selection of scan parameters in amplitude modulation AFM Let us consider which parameters we need to adjust in AM-AFM and what

• frequency is used as the set point. Historically, FM-AFM is commonly called non-contact atomic force microscopy [33]. However, repulsive forces are required to obtain high resolution, which implies some level of contact [34]. Qualitatively, this is easy to understand from the following reasoning. If a probe

• significantly simplified if the dissipation mode (DM) is used for scanning [5]. In the DM, the probe excitation frequency is maintained equal to its instant resonant frequency (as in FM-AFM), while the signal fed to the Z-scanner feedback loop is the oscillation amplitude (as in AM-AFM). The possibilities of

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• and fq in the in-phase mode (Figure 3 and Figure 6). We found a 0.05 mm tip has the best performance when the tip length is 0.65 mm in the anti-phase mode. However, Ax/Az in the anti-phase mode is 2.36, that is, φ is 23°. In frequency modulation-atomic force microscopy (FM-AFM), the frequency shift Δf

• than that of any tip with another diameter. Thus, 0.1 mm would be the best choice for the tip diameter. The last crucial factor to be considered is the Q factor. Lower Q factors will result in lower stability for both FM-AFM and amplitude modulation AFM (AM-AFM) [17]. As shown in Figure 9, the Q factor

Direct observation of the Si(110)-(16×2) surface reconstruction by atomic force microscopy

• Tatsuya Yamamoto,
• Ryo Izumi,
• Kazushi Miki,
• Takahiro Yamasaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2020, 11, 1750–1756, doi:10.3762/bjnano.11.157

• were performed using noncontact atomic force microscopy (NC-AFM) under ultrahigh vacuum (UHV) conditions, where the frequency modulation AFM (FM-AFM) method was used. The pressure was maintained below 3 × 10−11 Torr and the temperature was held at 78 K. As a probe, a commercially available Si

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• (amplitude and phase in AM-AFM [2], and frequency and amplitude (or dissipation) in frequency-modulation AFM (FM-AFM [3]). Another very important consideration concerning the ability to explore the full range of viscoelastic types of behavior in the sample is the ability of the cantilever to indent it. As

Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

• Christian Ritz,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2020, 11, 911–921, doi:10.3762/bjnano.11.76

• FM-AFM can be separated into a component induced by surface topography, Δftopo, and a component induced electrically, Δfel, therefore The coefficient a is proportional to the capacitance gradient C′′ and has the unit of Hz V−2. It is one of the three sample properties that are continuously estimated

• exfoliation from bulk graphite [32][33] and deposited on a piece of Si/SiO2. Measurements were carried out using an Asylum Research Cypher AFM connected to a Zurich Instruments HF2 lock-in amplifier. Figure 3 shows the results of the open-loop controller. During the FM-AFM measurement the tip voltage was

• , including the remaining static contribution present in standard FM-KFM. The improved topography measurement was demonstrated by a closed-loop scan on a graphene flake. The TD controller is also applicable as an open-loop technique. By modulating the tip–sample bias voltage during a regular FM-AFM

Quantitative determination of the interaction potential between two surfaces using frequency-modulated atomic force microscopy

• Nicholas Chan,
• Carrie Lin,
• Tevis Jacobs,
• Robert W. Carpick and
• Philip Egberts

Beilstein J. Nanotechnol. 2020, 11, 729–739, doi:10.3762/bjnano.11.60

• geometries. In this manuscript, frequency modulation (FM) AFM was used to determine the interaction forces between two irregularly shaped solids: the apex of a silicon AFM probe with its native oxide and a slightly roughened, nominally flat single-crystal diamond surface. This substrate was chosen due to its

• microscopy FM-AFM is a mode of AFM that allows for the probing of tip–sample interaction forces with the possibility of atomic resolution [41]. In this method, the probe is oscillated at its fundamental flexural resonance frequency (i.e., normal to the sample) and at a constant amplitude, while it is scanned

• analytical relationship between the resonance frequency shift and the tip–sample interaction force in FM-AFM was first derived by Giessibl [42] and is seen in the following equation: In Equation 1, Δf represents the change in the primary flexural resonance frequency of the cantilever near the surface, fres

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• ) driven by a Matrix SPM control unit. Pt/Ir-coated silicon cantilevers (EFM, Nanosensors, resonance frequency in the 45–115 kHz range) were annealed in situ to remove atmospheric contaminants. Topographic imaging was realized in FM mode (FM-AFM) with negative frequency shifts of a few Hz and vibrational

Ion mobility and material transport on KBr in air as a function of the relative humidity

• Dominik J. Kirpal,
• Korbinian Pürckhauer,
• Alfred J. Weymouth and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2019, 10, 2084–2093, doi:10.3762/bjnano.10.203

• relationship between humidity, water coverage and movement speed, however, is complex. In this study we investigated the surface of KBr, a salt crystal, by using frequency-modulation atomic force microscopy (FM-AFM) using a qPlus sensor [9][10][11]. The aim of our experiments is a qualitative and quantitative

Nanoscale spatial mapping of mechanical properties through dynamic atomic force microscopy

• Zahra Abooalizadeh,
• Leszek Josef Sudak and
• Philip Egberts

Beilstein J. Nanotechnol. 2019, 10, 1332–1347, doi:10.3762/bjnano.10.132

• clarify the term “dissipative interaction” in this manuscript to be any energy loss through a viscoelastic pathway, where the same definition has been used in frequency modulation (FM) AFM studies, such as in [47], to explain energy loss through vertical elastic displacement of step edges. In this case

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• the time resolution of the detection electronics. To relate the frequency shift of a cantilever to the tip–sample forces for FM-AFM, we turn to canonical perturbation theory using action-angle variables similar to the work done by Giessibl [37]. Derivation using canonical perturbation theory Starting

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• and repulsive regimes, but with inverted contrast [9]. Some FM-AFM studies using Si tips on graphite(0001) show a triangular pattern of bright spots instead of a honeycomb pattern [27]. Researchers have been trying to observe the three hidden carbon atoms. Hembacher et al. presented results showing

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• . eΔV corresponds to the bond dipole. Supporting Information Supporting Information File 218: Supporting Information. Figure S1 shows a FM-AFM height image obtained in UHV astride the step from a nanostructured TiO2/P3HT-COOH HHJ to the ITO electrode lying below. The applied DC sample bias was varied

Quantitative comparison of wideband low-latency phase-locked loop circuit designs for high-speed frequency modulation atomic force microscopy

• Kazuki Miyata and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2018, 9, 1844–1855, doi:10.3762/bjnano.9.176

• loop (PLL) circuit is the central component of frequency modulation atomic force microscopy (FM-AFM). However, its response speed is often insufficient, and limits the FM-AFM imaging speed. To overcome this issue, we propose a PLL design that enables high-speed FM-AFM. We discuss the main problems with

• proposed designs in the same field programmable gate array chip and quantitatively compared their performances. The results demonstrate that the performance of the proposed PLL is superior to that of the conventional PLL: 165 kHz bandwidth and 3.2 μs latency in water. Using this setup, we performed FM-AFM

• dissolution process; frequency modulation atomic force microscopy; high-speed atomic-resolution imaging; phase-locked loop; Introduction Frequency modulation atomic force microscopy (FM-AFM) is a powerful tool for investigating atomic- and molecular-scale structures of sample surfaces in various environments

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• ) at room temperature (RT) with in situ annealed Pt/Ir-coated silicon cantilevers (EFM, Nanosensors, resonance frequency in the 45–115 kHz range). Topographical imaging was performed in frequency modulation mode (FM-AFM) with negative frequency shifts of a few Hz and vibration amplitudes of a few tens

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

• Omur E. Dagdeviren and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2017, 8, 657–666, doi:10.3762/bjnano.8.70

• individually. This is in particular important as any change in f0 is an indication that some change in k may have taken place as well, as f0 and k are entangled properties [26]. In contrast, the thermal noise δfthermal of the measurement, which is one of the main noise sources in FM-AFM, scales with Q−1/2

Generalized Hertz model for bimodal nanomechanical mapping

• Aleksander Labuda,
• Marta Kocuń,
• Waiman Meinhold,
• Deron Walters and
• Roger Proksch

Beilstein J. Nanotechnol. 2016, 7, 970–982, doi:10.3762/bjnano.7.89

• imaging modes, such as frequency-modulation (FM) AFM [23]. Separating the storage and loss moduli, and quantifying them, requires either additional independent observables or the use of spectroscopic methods. Spectroscopic techniques rely on changing the operating conditions of the cantilever to provide

• based on FM-AFM techniques that rely on elaborate mathematical theories [36][37][38][39][40][41], involving fractional calculus and Laplace transforms for relating AFM observables to nanomechanical properties. The mathematical complexity of these techniques can obscure physically intuitive understanding

Coupled molecular and cantilever dynamics model for frequency-modulated atomic force microscopy

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2016, 7, 708–720, doi:10.3762/bjnano.7.63

• . It is shown how this may lead to a systematic shift between the periodic patterns obtained from the frequency and from the damping signal, respectively. Keywords: atomic force microscopy; frequency-modulated atomic force microscopy (FM-AFM); energy dissipation; Introduction The physical background

• of the dissipation signal in frequency-modulated atomic force microscopy (FM-AFM) was unclear for a long time, and different effects had been discussed, before it was shown that the main contribution comes from adhesion hysteresis [1][2][3]. However, agreement between theoretical predictions and

• ]. It must be kept in mind, though, that the atomic interaction is only one among several important factors that influence FM-AFM simulations. For example the shape of the tip can change the dissipation rate by as much as 100% [21]. For our present purpose, to investigate qualitatively, what the effect

Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

• Hannes Beyer,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 432–438, doi:10.3762/bjnano.7.38

• ; frequency-modulation atomic force microscopy; high-resolution; length-extension resonator; Introduction Frequency-modulated atomic force microscopy (FM-AFM) is the method of choice to image nanoscale structures on surfaces down to the atomic level. Whereas atomic resolution is routinely achieved in ultra

• [4][5]. Recently, atomic resolution has been achieved with a qPlus sensor in air on potassium bromide and graphite [2][6]. In this paper, we demonstrate the suitability of the piezoelectric self-sensing length-extension resonator (LER) [7][8] for high-resolution FM-AFM imaging in air. The LER has a

• separate feedback (constant-amplitude FM-AFM). Tips from commercial cantilevers (e.g., Olympus AC160-R3, Nanosensors SSS-NCH) are glued to the front face of the protruding oscillating beam with silver epoxy (E4110-LV, EPO-TEK Epoxy Technology). Environmental conditions are monitored with a digital

Efficiency improvement in the cantilever photothermal excitation method using a photothermal conversion layer

• Natsumi Inada,
• Hitoshi Asakawa,
• Taiki Kobayashi and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2016, 7, 409–417, doi:10.3762/bjnano.7.36

• nominal spring constants of 42 and 85 N/m (PPP-NCHAuD and AC55). In addition, we demonstrate high stability of the PTC layer in liquid by long-term FM-AFM imaging of mica with atomic resolution in phosphate buffer saline (PBS) solution. Results and Discussion Preparation of PTC layers Figure 1 shows a

• and after the measurement are almost the same (Figure 6a). Figure 6b–f shows FM-AFM images of a mica surface obtained in PBS solution using an AC55 cantilever coated with a PTC layer. After adjusting the imaging parameters such as Δf, A and feedback gains to obtain atomic resolution, long-term FM-AFM

• not have any negative influence on the atomic-scale FM-AFM imaging in liquid. Conclusion In this study, we proposed a method for improving the photothermal excitation efficiency in dynamic-mode AFM using a PTC layer made of colloidal graphite. We have established a procedure to prepare a PTC layer

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• selection of operating parameters and slow scanning speeds. Furthermore, the choice of suitable bandwidths for topography and KFM feedback is more involved in traditional FM-AFM/FM-KFM implementations. For example, when Δf is used as an input to the lock-in amplifier detecting the electrostatic modulation

• finding the noise power spectral density of the frequency shift signal in FM-AFM [24]. When the narrow-band conditions are not met (β >> 1), the iterative scheme for the sideband amplitudes in Equation 4 and Equation 5 still approaches the Bessel functions describing the sideband amplitudes in a general

Improved atomic force microscopy cantilever performance by partial reflective coating

• Zeno Schumacher,
• Yoichi Miyahara,
• Laure Aeschimann and
• Peter Grütter

Beilstein J. Nanotechnol. 2015, 6, 1450–1456, doi:10.3762/bjnano.6.150

• 2.5 times, hence resulting in higher signals on the photodiode. In frequency modulated (FM) AFM, the mechanical quality (Q-)factor of the cantilever plays an important role, since the measurable minimal force gradient in FM-AFM is [1]: where Q is the mechanical Q-factor of the cantilever, kL the force

• the NCLR and soft type respectively. In the following paragraph we will highlight the advantage of a partial reflective coating on NCLR and Soft cantilevers for FM-AFM and static AFM operation, respectively. Advantages for FM-AFM: recovering intrinsic Q-factor values Figure 1 shows the Q-values for

• the NCLR cantilever with different coating coverages measured in high vacuum. For each of the uncoated and fully coated cantilevers, the average of at least 3 different cantilevers is plotted. As previously mentioned, the minimal detectable force in FM-AFM can be reduced by increasing the Q-factor