Multi-frequency tapping-mode atomic force microscopy beyond three eigenmodes in ambient air

• Santiago D. Solares,
• Sangmin An and
• Christian J. Long

Beilstein J. Nanotechnol. 2014, 5, 1637–1648, doi:10.3762/bjnano.5.175

• time-dependent trajectory of the tip and individual eigenmodes through simulation of ideal cantilevers. Figure 2a illustrates typical tip trajectories simulated for pentamodal operation when imaging a polymer sample. Here the first eigenmode free amplitude is 80 nm and the higher mode free amplitudes

• are set to either 3 or 8 nm, as indicated on the graphs, which correspond to typical amplitude ratios used in bimodal and trimodal AFM. As the higher mode amplitudes are increased, the tip trajectory has the appearance of becoming increasingly noisy, which occurs in part because the various

• surface to different depths every successive impact, which is not surprising given the irregular tip trajectory. Furthermore, the graph shows that impacts become less regular as the higher mode amplitude increases, which is also as expected. Such irregular impacts constantly generate new transients that

Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters

• Subarna Khanal,
• Ana Spitale,
• Nabraj Bhattarai,
• Daniel Bahena,
• J. Jesus Velazquez-Salazar,
• Sergio Mejía-Rosales,
• Marcelo M. Mariscal and
• Miguel José-Yacaman

Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150

• parameters, the mean square displacement (MSD) of the Pt atoms in the nanoalloy was calculated by taking previous configurations in the recorded trajectory as reference configuration. Moreover, the MSD reflects the relative change of diffusivity of the atoms at different temperatures and the activation

Double layer effects in a model of proton discharge on charged electrodes

• Johannes Wiebe and
• Eckhard Spohr

Beilstein J. Nanotechnol. 2014, 5, 973–982, doi:10.3762/bjnano.5.111

• behavior cannot be based solely on the electrochemical potential (or surface charge) but needs to resort to the molecular details of the double layer structure. Keywords: electrocatalysis; interfacial electrochemistry; proton discharge; reactive force field; trajectory calculations; Introduction One of

• trajectories are aligned in a straightforward manner at their starting position. Thus, the average of some observable O over trajectories i, is calculated according to where the sum runs over all trajectories and denotes the initial time of the ith trajectory run. Figure 3 shows the average distance of the

• discharge occurs fluctuatively. Note that, in order to avoid excessive noise for long times (when few trajectories contribute to the average, since many trajectories have been terminated already after discharge), we have artificially extended each terminated trajectory by using the constant final value of

Energy dissipation in multifrequency atomic force microscopy

• Valentina Pukhova,
• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2014, 5, 494–500, doi:10.3762/bjnano.5.57

• given in units of the first free flexural frequency f1 = 11.7 kHz. The theoretical scaling for the force constants (ki) is reported for each flexural mode [1]. Optical sensibilities σi and the damped harmonic oscillator parameters used for the reconstruction of the tip trajectory [5]. Total dissipated

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• with high accuracy (unfortunately this is not practical and only possible within highly controlled experiments) and the cantilever behaves in an ideal manner, it is not possible to determine the true tip trajectory from the photodetector reading. This is because the photodetector measures cantilever

• are not meaningful unless the true probe trajectory is known. This is a challenge that remains unsolved even in the most sophisticated base-excitation experiments, which is further compounded by the non-ideal behavior of piezo shaker systems, cantilevers and the surrounding fluid [19][23][24]. One

• a Hamaker constant of 2 × 10−19 J (no screening was considered for the simulations in air). Unless otherwise indicated, the trajectories shown indicate the true eigenmode or tip response, as opposed to the photodetector reading, which does not necessarily correspond to the true trajectory (as

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• one, mostly by smearing out the sharp ∂Fz/∂z(ztip) peak. Finally, we combine our findings regarding surface corrugation and tip stiffness to perform the most realistic simulation of our single-molecule manipulation experiments yet. As in the experiment, we use a strictly vertical tip trajectory that

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• certain limitations. AFM is used for both displacement and visualization of the initial and the final position of the NPs, but these two procedures cannot be performed simultaneously. Therefore there is no real-time visual feedback in a single line scan concerning the trajectory of the particle and its

• type of motion (sliding, rolling or rotation) during the manipulation event. It is possible to extract trajectory and motion type data from complete AFM images as it was recently demonstrated in several works [4][7][8][9]. However, such a process is time consuming, since it requires a large amount of

• their trajectory, in order to distinguish between continuous and abrupt motions (jumps), and to correlate the movement of the NPs with the measured tip–NP interaction force. The first series of measurements was carried out with 19 Au NPs. Figure 5 represents a typical manipulation experiment with Au NPs

Exploring the retention properties of CaF₂ nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

• Matthias Wasem,
• Joachim Köser,
• Sylvia Hess,
• Enrico Gnecco and
• Ernst Meyer

Beilstein J. Nanotechnol. 2014, 5, 36–43, doi:10.3762/bjnano.5.4

• trajectory angle of the manipulated particle is mainly a function of the intrinsic particle–substrate contact radius R. With exception for the first scan line, the displacement angle of a particle θ with respect to the fast scan axis is given by: where α0 = arcsin [1−(b/R)]. The theoretical predicted

• deflection angle depending only on the particle-substrate contact radius derived from Equation 1 is illustrated in Figure 1a. By reading out the trajectory angle of the deflected particles we get the particle–substrate contact size distribution. For the case of particles with plane facing adsorbed on smooth

• and atomically flat substrates, such as mica, the trajectory angle distributions can be approximately regarded as the size distribution of the synthesized particles. In order to calculate the power dissipation from the phase-lag of the cantilever relative to the excitation, we used the method of

Simulation of electron transport during electron-beam-induced deposition of nanostructures

• Francesc Salvat-Pujol,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2013, 4, 781–792, doi:10.3762/bjnano.4.89

• . A particle trajectory is represented as a series of states (rn,en,dn), where n labels the scattering event at rn that leads to an energy En and a direction dn (see below in Figure 1). Several random variables are sampled from their respective probability distribution functions. The length of the

• positive charge in the material and to new particles, thus leading to a “shower” of particles. If an electron crosses a boundary into an adjacent material, its trajectory history is stopped at the other side of the interface and restarted with the new material transport properties. This can be done any

• time, since electron trajectories are modelled as Markov processes (the future of the trajectory is dependent only on the present state, and not on the past). The trajectory history of an electron is stopped when its energy drops below 50 eV. The electron is then considered to be absorbed by the medium

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• processes in a system where low energy barriers are effectively washed out by zero-point motion. Because the initial configuration for the QMD simulations of the nanochannel was taken from the classical MD trajectory, it was important to check the stability of the model channel. No strong drift of the

Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

• Hlengisizwe Ndlovu,
• Alison E. Ashcroft,
• Sheena E. Radford and
• Sarah A. Harris

Beilstein J. Nanotechnol. 2013, 4, 429–440, doi:10.3762/bjnano.4.50

• models with these new SMD parameters. Analysis methods and calculations Secondary structure content, hydrogen bond and thermodynamic analysis of the production-phase MD simulations was performed on snapshots sampled every 1 ps from the final 10 ns of the converged trajectory. Secondary structure content

• interfaces interrogated during the simulation. Capping: The comparative response of uncapped (filled bar) and capped (striped bar) for the (c) “peel” and (d) “stretch” directions. Molecular configurations sampled from the “peel” SMD trajectory for the (a) 8 × 2 and (b) 16 × 2 fibril models of the class1-P

Guided immobilisation of single gold nanoparticles by chemical electron beam lithography

• Patrick A. Schaal and
• Ulrich Simon

Beilstein J. Nanotechnol. 2013, 4, 336–344, doi:10.3762/bjnano.4.39

• CASINO v2.48 (monte CArlo SImulation of electroN trajectory in sOlids) [28]. Therefore the following density values were used: ρ(Si) = 2.3290 g·cm−3 [29], ρ(SiO2) = 2.196 g·cm−3 [29], ρ(CSPETCS) = 1.35 g·cm−3 (estimation using density values of commercially available solutions). Schematic drawing of used

Influence of the solvent on the stability of bis(terpyridine) structures on graphite

• Daniela Künzel and
• Axel Groß

Beilstein J. Nanotechnol. 2013, 4, 269–277, doi:10.3762/bjnano.4.29

• molecular dynamics trajectory range from 0.07 g/cm3 for UFF with Gasteiger charging, up to 1.01 g/cm3 for Dreiding with QEq charges. A value of 0.997 g/cm3 would have been expected [33]. With UFF, the deviation from the experiment is particularly high with both charging methods. Dreiding performs well with

• influence of the runtime of the trajectories on the average values. Total runtimes of 150 ps are used in order to evaluate the influence of the length of equilibration phase and actual trajectory. For the larger systems, the extreme cases of 20 ps equilibration time and 130 ps runtime on the one hand, and

• natural fluctuations in the volume throughout the trajectory. For the benzene in water case, with 300 water molecules the volume changes by 6% when a benzene molecule is added to the system whereas the standard deviation amounts to 8% of the average volume for the benzene–water solvated system. With a

Calculation of the effect of tip geometry on noncontact atomic force microscopy using a qPlus sensor

• Julian Stirling and
• Gordon A. Shaw

Beilstein J. Nanotechnol. 2013, 4, 10–19, doi:10.3762/bjnano.4.2

• = 90° to oscillation parallel to the surface, we obtain It is important to note that as the angle of tip rotation is so small, the motion of the tip apex should not be thought of as circular motion, but instead the tip apex is moving over a linear trajectory at an angle ψ to the surface, with

Diamond nanophotonics

• Katja Beha,
• Helmut Fedder,
• Marco Wolfer,
• Merle C. Becker,
• Petr Siyushev,
• Mohammad Jamali,
• Anton Batalov,
• Christopher Hinz,
• Jakob Hees,
• Lutz Kirste,
• Harald Obloh,
• Etienne Gheeraert,
• Boris Naydenov,
• Ingmar Jakobi,
• Florian Dolde,
• Sébastien Pezzagna,
• Daniel Twittchen,
• Matthew Markham,
• Daniel Dregely,
• Harald Giessen,
• Jan Meijer,
• Fedor Jelezko,
• Christoph E. Nebel,
• Rudolf Bratschitsch,
• Alfred Leitenstorfer and
• Jörg Wrachtrup

Beilstein J. Nanotechnol. 2012, 3, 895–908, doi:10.3762/bjnano.3.100

• entirely by straggle, i.e., the deviation of the ion trajectory inside the diamond crystal, caused by collisions with the lattice atoms. Such implantation processes can be studied in detail with theoretical simulations. A suitable method is scattering calculations. The “Stopping Range of Ions in Matter

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• , or four foils 30 µm thick) can be irradiated. Each ionic projectile induces electronic excitation and ionisation processes in a cylindrical zone along its trajectory. In polymers, chemical bonds are destroyed and small volatile fragments (e.g., H2, CO, CO2, hydrocarbons) easily outgas [28]. This

• . The production of membranes with open channels requires selective dissolution of the latent tracks (cf. subsection 1.1.2). Selective track etching of channels with small size distributions requires continuous and homogeneous damage along the ion trajectory. Best results are achieved when the energy

Radiation-induced nanostructures: Formation processes and applications

• Michael Huth

Beilstein J. Nanotechnol. 2012, 3, 533–534, doi:10.3762/bjnano.3.61

• transfer, i.e., the rate at which ionization is created along the particle trajectory, can amount to more than 100 keV/µm. Proximal tissue, in contrast, only receives radiation by means of the excited secondary electrons whose trajectories are transverse to the particle track. For the electrons in the low

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

• Gregor Hlawacek,
• Vasilisa Veligura,
• Stefan Lorbek,
• Tijs F. Mocking,
• Antony George,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

• larger deviation from the initial particle trajectory. We will discuss this in more depth in the next paragraph. For the present case in which a light adlayer (either carbon or cobalt) covers a heavier substrate (silicon or germanium), (1) does not play a significant role and (2) will be weak in general

• . This can be seen in the organic overlayer, in particular for the rims of the vertical stripes of PFS in Figure 1(b). The edges of the stripes are thicker [7], and this leads to an increased chance for an ion to be deviated from the initial trajectory. Consequently, this results in more backscattering

Channeling in helium ion microscopy: Mapping of crystal orientation

• Vasilisa Veligura,
• Gregor Hlawacek,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 501–506, doi:10.3762/bjnano.3.57

• } oriented fcc crystal is tilted by 35° with respect to the incoming beam, for a specific azimuthal orientation, the {110} planes will be parallel to the trajectory of the incoming helium. For symmetry reasons, this configuration can be found every 120°. Particles traveling along the low index <110

Models of the interaction of metal tips with insulating surfaces

• Thomas Trevethan,
• Matthew Watkins and
• Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

• contributions to surface science [1][2][3]. In NC-AFM the tip is prevented from jumping into mechanical contact with the sample surface due to the large restoring force of the cantilever at the turning point of the tip trajectory when it is closest to the surface. As a result, the instrument can probe all

Analysis of fluid flow around a beating artificial cilium

• Mojca Vilfan,
• Gašper Kokot,
• Andrej Vilfan,
• Natan Osterman,
• Blaž Kavčič,
• Igor Poberaj and
• Dušan Babič

Beilstein J. Nanotechnol. 2012, 3, 163–171, doi:10.3762/bjnano.3.16

• height z above the surface, to which the cilium was attached. In order to observe the generated fluid flow, nonmagnetic tracer particles were introduced into the system and their motion was recorded. A typical trajectory of a tracer particle is shown in Figure 2a. The cilium was attached to the surface

• . The colours of the arrows specify the velocity amplitude. The second component of the trajectory is a translation in the −y direction that follows the generated directed fluid flow. Since only one cilium was used in the experiment, the translational flow is not straight but has an additional

• experiment. Analytical calculation of the average flow velocity A very basic approach to modelling the flows around a beating cilium, regardless of its precise beat pattern, consists of replacing the cilium with a small hypothetical particle circling along a tilted elliptical trajectory [19]. We have shown

Current-induced forces in mesoscopic systems: A scattering-matrix approach

• Niels Bode,
• Silvia Viola Kusminskiy,
• Reinhold Egger and
• Felix von Oppen

Beilstein J. Nanotechnol. 2012, 3, 144–162, doi:10.3762/bjnano.3.15

• ) expectation value , evaluated for a given trajectory X(t) of the mechanical degrees of freedom, plus fluctuations containing both Johnson–Nyquist and shot noise. These fluctuations give rise to a Langevin force ξν. Hence Equation 7 becomes where the trace “tr” is taken over the dot levels, and we have

• current-induced forces show that we need to evaluate the electronic Green’s function for a given classical trajectory X(t). In doing so, we can exploit the assumption that the mechanical degrees of freedom are slow compared to the electrons. Thus, we can approximate the Green’s function by its solution to

• drive the system into a limit cycle by varying the bias potential. The existence of this limit cycle is shown in Figure 8a, where we have plotted various Poincaré sections of the nonlinear system without fluctuations. The figure shows the trajectory in phase space of the (dimensionless) oscillator

Parallel- and serial-contact electrochemical metallization of monolayer nanopatterns: A versatile synthetic tool en route to bottom-up assembly of electric nanocircuits

• Jonathan Berson,
• Assaf Zeira,
• Rivka Maoz and
• Jacob Sagiv

Beilstein J. Nanotechnol. 2012, 3, 134–143, doi:10.3762/bjnano.3.14

• silver-film stamp (Ag/OTS/Si), whereas precise delivery of metal to selected surface sites within selected OTSeo features of such a monolayer nanopattern can be realized in a serial mode, by moving a positively biased silver-coated SFM tip along a planned trajectory across the patterned area of the

• programmed to move across the surface according to a predefined trajectory, it should be possible to create more complex "pattern-within-pattern" structures by serial delivery of metal to selected surface sites within selected OTSeo template regions of a prepatterned OTS monolayer. For example, in the case

Surface induced self-organization of comb-like macromolecules

• Konstantin I. Popov,
• Vladimir V. Palyulin,
• Martin Möller,
• Alexei R. Khokhlov and
• Igor I. Potemkin

Beilstein J. Nanotechnol. 2011, 2, 569–584, doi:10.3762/bjnano.2.61

• findings make the use of the persistence length meaningless as a quantity for the description of the local bending properties. The trajectory of comblike macromolecule (semiflexible cylindrical object) also follows a power law dependence, rather than exponential [23], and thus cannot be correctly described

Functional morphology, biomechanics and biomimetic potential of stem–branch connections in Dracaena reflexa and Freycinetia insignis

• Tom Masselter,
• Sandra Eckert and
• Thomas Speck

Beilstein J. Nanotechnol. 2011, 2, 173–185, doi:10.3762/bjnano.2.21

• not significantly. A possible reason for this may be the lack of anomalous secondary growth in F. insignis which is thereby restricted to develop only comparatively thin main stems and lateral branches throughout its entire ontogenetic trajectory. It can be argued that these ‘thin branchings’ in F