Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• (c). The STS data for defects 1 and 2 were acquired with the same tip. The spectra are shifted vertically by 0.02 nS. Feedback loop parameters prior to spectroscopy: 500 mV, 50 pA. Atomic force and scanning tunneling microscopy of defect types 1 and 2 in graphene on Ir(111). (a) Constant-height AFM

• tip excursion used for the constant-height Δf current maps in (a–d). Displacement Δz = 0 defines the tip–sample distance at which the feedback loop was deactivated above pristine graphene (10 mV, 50 pA). Vertical probe–surface distance dependence of AFM topographies of defect 1. (a–c) Constant-height

• is defined by the feedback loop parameters 10 mV and 50 pA above intact graphene. The same tip–surface distance prior to data acquisition above the defect is ensured by taking the apparent height difference at the feedback loop parameters into account. Total vertical force F as a function of tip

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

• highly desirable. Furthermore, we would like the integrated sensor package, that is, transducer and detector, to be easily exchangeable, as AFM tips are frequently damaged when scanning over unknown surface features. Dynamic AFM is typically operated in two alternative modes of scanning feedback, namely

Enhanced feedback performance in off-resonance AFM modes through pulse train sampling

• Mustafa Kangül,
• Navid Asmari,
• Santiago H. Andany,
• Marcos Penedo and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2024, 15, 134–143, doi:10.3762/bjnano.15.13

• vertical force changes during a defined time window of the tip–sample interaction. Through this, we use multiple samples in the proximity of the maximum force for the feedback loop, rather than only one sample at the maximum force instant. This method leads to improved topography tracking at a given ORT

• rate and therefore enables higher scan rates while refining the mechanical property mapping. Keywords: atomic force microscopy (AFM); feedback control; off-resonance tapping (ORT); pulsed-force mode; Introduction Constant force mode, a widely used AFM imaging mode, utilizes a feedback controller that

• mode, where force-versus-distance curves are acquired periodically. The maximum cantilever deflection during one period, corresponding to the maximum exerted force, is sampled and fed into a feedback controller. The tip–sample contact duration is limited and easily tunable compared to the constant

Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates

• Julian Skolaut,
• Jędrzej Tepper,
• Federica Galli,
• Wulf Wulfhekel and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97

• integrated preamplifier, whose feedback resistor of 1 GΩ fixes the maximum measurable current to 12 nA, sets the amplification to 109 V/A, and allows one to measure currents down to few tens of picoamperes. In the studies presented here, two types of CAFM-probes were used. For the studies on DDT SAMs on Au

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• mechanical resonance frequency (f0) executed by the lock-in amplifier 1 and the generated topography signal is controlled by the Z feedback. A sinusoidal AC bias (VAC) with drive of 1 V and frequency (fAC) of 5 kHz is applied to the tip through lock-in 2, generating a signal with a frequency of f0 ± fAC near

• measure the sideband signals at f0 + fAC and f0 − fAC. Then, their average is used for the KPFM feedback to adjust the DC bias. If fAC is chosen to be small enough, such that the sideband peaks are close to f0, the amplitude of these peaks will be enhanced by the mechanical resonance of the cantilever

• leading to a better signal-to-noise ratio. The feedback applies a DC bias (VDC) matching the potential difference between the tip and the sample, which compensates for the electrostatic force. Therefore, the sidebands disappear. The value of VDC corresponds to the contact potential difference

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• + dc potential is applied, the KPFM tip scans across a surface. The ac signal is sinusoidal with a frequency that equals the mechanical resonance of the cantilever. The four-quadrant detector gives feedback in order to minimize cantilever oscillation modifying the dc signal providing the sample surface

On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets

• Keith R. Paton,
• Konstantinos Despotelis,
• Naresh Kumar,
• Piers Turner and
• Andrew J. Pollard

Beilstein J. Nanotechnol. 2023, 14, 509–521, doi:10.3762/bjnano.14.42

• Research, Oxford Instruments, UK). AFM images were recorded using Si AFM probes (MikroMasch HQ:NSC15, 40 N/m, 325 kHz, MikroMasch, Bulgaria) in tapping-mode feedback. AFM images were measured in square areas between 6 μm × 6 μm and 8 μm × 8 μm using 1024 × 1024 pixels with a scan speed below 20 μm·s−1. To

Nanotechnology – a robust tool for fighting the challenges of drug resistance in non-small cell lung cancer

• Filip Gorachinov,
• Fatima Mraiche,
• Diala Alhaj Moustafa,
• Ola Hishari,
• Yomna Ismail,
• Jensa Joseph,
• Maja Simonoska Crcarevska,
• Marija Glavas Dodov,
• Nikola Geskovski and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2023, 14, 240–261, doi:10.3762/bjnano.14.23

Observation of collective excitation of surface plasmon resonances in large Josephson junction arrays

• Roger Cattaneo,
• Mikhail A. Galin and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2022, 13, 1578–1588, doi:10.3762/bjnano.13.132

• matching with free space and improves the radiation power efficiency. The cavity modes in the electrodes are excited collectively by the JJs, which are, in turn, mutually phase-locked by the modes. This provides a positive feedback mechanism allowing for the synchronization of large arrays without direct

• pumped collectively by the junctions, which are in turn mutually phase-locked by the modes. This provides a positive feedback mechanism, which allows for the synchronization of large arrays without direct interjunction interaction. The electromagnetic wave emission in this case is facilitated by the

Studies of probe tip materials by atomic force microscopy: a review

• Ke Xu and
• Yuzhe Liu

Beilstein J. Nanotechnol. 2022, 13, 1256–1267, doi:10.3762/bjnano.13.104

• of tip. The attachment process produces a tip with stability and higher sensitivity during image acquisition. The smaller tip diameter produces a higher peak force, resulting in very sharp images being collected. In general, if good images are to be achieved, it is at the expense of reduced feedback

• stability. This is partly due to the increased wear of the tip and electrostatic effects. SWCNT-modified tips offer feedback stability and higher current sensitivity, and SWCNT has good wear resistance. The overall performance of SWCNT probes shows that they can be produced at a lower price and meet all the

Application of nanoarchitectonics in moist-electric generation

• Jia-Cheng Feng and
• Hong Xia

Beilstein J. Nanotechnol. 2022, 13, 1185–1200, doi:10.3762/bjnano.13.99

• for green energy in the near future. MEGs are also widely used in sensors [54]. For example, a moisture-eletric touch sensor array can provide uniform and sensitive touch feedback (Figure 10e). As shown in Figure 10f, a breath detector can monitor different breathing patterns, including short breaths

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• -scan piezo reasonably high, as required for a fast feedback. Furthermore, to avoid instrument downtime due to piezo tube fractures, sample exchange inside the UHV must be performed with minimal force applied to the scan piezo. The schematic setup of our instrument is displayed in Figure 3b. Our

Comparing the performance of single and multifrequency Kelvin probe force microscopy techniques in air and water

• Jason I. Kilpatrick,
• Emrullah Kargin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2022, 13, 922–943, doi:10.3762/bjnano.13.82

• capable of atomic-scale spatial resolution and nanosecond time resolution under specific conditions. KPFM-based techniques can largely be classified as either “open loop” (OL) or “closed loop” (CL). CL techniques employ a feedback loop to apply a bias to compensate for the electrostatic force (or force

• gradient) between the tip and sample. CL techniques are more common than OL techniques due to the ease of implementation, wide-scale availability, and direct measurement of the apparent CPD. OL techniques, by contrast, are feedback-free and can be used to determine the CPD without the need to apply a DC

• currents and unwanted electrochemical reactions) [9][33][34][35]. OL techniques avoid the limitations and artefacts that can arise when using a feedback loop, for example, bandwidth limitations due to the time constant of the feedback loop [29], increased noise [36][37], and electrical crosstalk [38][39

Efficiency of electron cooling in cold-electron bolometers with traps

• Dmitrii A. Pimanov,
• Vladimir A. Frost,
• Anton V. Blagodatkin,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80

• efficiency. This concept is based on negative electrothermal feedback for an incoming signal, which is due to the direct electron cooling of the absorber by the normal metal–insulator–superconductor (NIS) tunnel junctions. Recently, in receivers with cold-electron bolometers [4][5][6], electron cooling from

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• “Ph2”) and from C60 (“a”–“e”) are labeled and their evolution is indicated with dotted lines. Scanning tunneling spectrum acquired at constant tip–surface separation (open feedback loop) on the C60/ZnTPP/Fe(001)–p(1 × 1)O system (black) and on the ZnTPP/Fe(001)–p(1 × 1)O surface (red). The black curves

Temperature and chemical effects on the interfacial energy between a Ga–In–Sn eutectic liquid alloy and nanoscopic asperities

• Yujin Han,
• Pierre-Marie Thebault,
• Corentin Audes,
• Xuelin Wang,
• Haiwoong Park,
• Jian-Zhong Jiang and
• Arnaud Caron

Beilstein J. Nanotechnol. 2022, 13, 817–827, doi:10.3762/bjnano.13.72

• plotted for both forward and backward directions as presented in Figure 3. There, the normal force plots show the normal force signal as controlled by the feedback loop in red color, while the normal force traces in blue and orange colors were calculated from the height traces in, respectively, the

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• frequency. The AFM measurement was carried out in tapping mode. A 633 nm laser light aimed at the back side of the cantilever tip was reflected toward a position-sensitive photodetector, which provides feedback signals to piezoelectric scanners that maintain the cantilever tip at constant height (force

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

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

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• tandem lock-in amplifiers, tandem SPV-KPFM [24], which can measure only slow SPV responses on the subsecond time scale because it uses closed-loop DC bias feedback on the millisecond-to-second time scale. Sugawara et al. used two parallel lock-in amplifiers, parallel SPV-KPFM [25], which also detects

• energy resolutions and the image acquisition time of AC-KPFM in the AM mode are comparable to those of the classical KPFM in the AM mode, because both methods detect the electrostatic force, and the response time of the bias feedback τ limits the image acquisition time. To reach sufficient sensitivity

• classical KPFM. The spatial and energy resolutions and the image acquisition time of AC-KPFM in the FM mode are comparable to those of the classical KPFM in the FM mode, because both methods detect the electrostatic force gradient and the response time of the bias feedback τ limits their image acquisition

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

• resonant frequency (usually 40–400 kHz). As the distance between the probe and the sample decreases, the oscillation amplitude A also decreases. A certain amplitude value is selected as a set point Asp (a reference level). A feedback loop compares the current amplitude value with Asp and, moving the Z

• 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

• . If there is a vertical wall of height h, then, at the moment when the probe quickly hits the wall, the oscillation amplitude decreases by the amount of h. The error signal δA = A − Asp appears, defined by the difference of the current amplitude and Asp. The value of δA = −h is fed to the feedback

Open-loop amplitude-modulation Kelvin probe force microscopy operated in single-pass PeakForce tapping mode

• Gheorghe Stan and
• Pradeep Namboodiri

Beilstein J. Nanotechnol. 2021, 12, 1115–1126, doi:10.3762/bjnano.12.83

• data is limited. Moreover, the finite response time of the CL feedback (of the order of milliseconds in some cases) prevents the use of CL KPFM from observing fast electrodynamic processes. Some of these impediments are addressed in OL implementations such as time-resolved electrostatic force

• measurements. The observed difference in the CPD measured by these two CL KPFM modes is well documented [36][50][51][58] and is related to the physical quantity on which each mode operates. On one hand, the feedback loop of the CL AM-KPFM tries to nullify the magnitude of the electrostatic force developed

• measurements are made and most likely access to the raw response of the probe under an electrostatic interaction with the sample. These requirements are very hard to be fulfilled by a CL KPFM method, where the momentarily reported CPD is the result of a feedback loop algorithm. However, the data are fully

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• microscopy is an option to study the membrane surface nanoscopically without dye labeling or laser light exposure. In scanning probe microscopy a nanoprobe is kept at a constant distance from the sample surface by maintaining a local interaction signal constant via a feedback loop [16]. If the interaction

• surface and cell migration happen rather slowly, they should only contribute to low-frequency fluctuations. To investigate the frequency behavior we focus on measuring the height with activated feedback loop in the frequency range of 0.2 to 500 Hz. Most systems exhibit an f−m spectral power density (SPD

• nanopipette was kept at constant lateral position over the cell and either temporal height variations with activated feedback loop or current variations at deactivated feedback loop were acquired. Temporal current and height spectra were evaluated using the Igor Pro software (WaveMetrics, Inc.). As main

Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

• Eduardo Serralta,
• Nico Klingner,
• Olivier De Castro,
• Michael Mousley,
• Santhana Eswara,
• Serge Duarte Pinto,
• Tom Wirtz and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2020, 11, 1854–1864, doi:10.3762/bjnano.11.167

• controlled by a motion controller (Nanomotion XCDX) using a closed feedback loop with optically encoded linear rails (Schneeberger Miniscale Plus). This construction is compatible with the high-vacuum requirements, is self-locking, requires no mechanical feedthroughs nor lubricants, and provides high

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

• cantilever was used, which was cleaned by Ar+ sputtering to remove the oxide and contamination on the tip. The deflection of the cantilever was measured by the optical beam deflection method. The topography of the surface was imaged while feedback electronics were used to adjust the tip–sample distance to

Cu₂O nanoparticles for the degradation of methyl parathion

• Juan Rizo,
• David Díaz,
• Benito Reyes-Trejo and
• M. Josefina Arellano-Jiménez

Beilstein J. Nanotechnol. 2020, 11, 1546–1555, doi:10.3762/bjnano.11.137

• comments, suggestions, and feedback from his colleagues Inti Zumeta Dubé and Fabián Ruiz Ruiz. Funding Juan Rizo would like to thank CONACyT for his PhD fellowship (grant # 240056). David Diaz wants to thank FQ-UNAM for the financial support from “Programa de Apoyo a los Estudios de Posgrado” (PAEP # 5000