Numerical analysis of single-point spectroscopy curves used in photo-carrier dynamics measurements by Kelvin probe force microscopy under frequency-modulated excitation

• Pablo A. Fernández Garrillo,
• Benjamin Grévin and
• Łukasz Borowik

Beilstein J. Nanotechnol. 2018, 9, 1834–1843, doi:10.3762/bjnano.9.175

• experimental results as additional information about the photo-carrier dynamics of the sample can be gained via the numerical analysis. Keywords: carrier dynamics; carrier lifetime; carrier recombination; Kelvin probe force microscopy; nanostructured photovoltaics; numerical simulations; photo-carrier

• data points obtained by numerical simulations using τb = 1, 10 and 20 μs. The data points was taken from Figure 4 of [3]. Simulated SPV as a function of the time for different excitation modulation frequencies, the red lines indicate the average SPV value for each modulation condition. Modulation

Know your full potential: Quantitative Kelvin probe force microscopy on nanoscale electrical devices

• Amelie Axt,
• Ilka M. Hermes,
• Victor W. Bergmann,
• Niklas Tausendpfund and
• Stefan A. L. Weber

Beilstein J. Nanotechnol. 2018, 9, 1809–1819, doi:10.3762/bjnano.9.172

• elucidated by numerical simulations, which is beyond the scope of this work. Conclusion Our results show that generally, FM-KPFM methods provide more quantitative and reliable results. For all experiments, FM-KPFM measured more than 96% of the externally applied potential difference, even in the presence of

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• results to numerical simulations, where agreement is obtained, thereby confirming the near-field nature of the images. Our approach does not require any advanced equipment and we suggest that it could be applied to any type of sample, while keeping the measurement times reasonably short. Keywords

• are compared to numerical simulations by finite elements. A good agreement is found, attesting to the validity of our method of analysis and making it an alternative technique to study the hot spots in plasmonic nanostructures. Results and Discussion As mentioned previously, the near-field information

• between the efficiency of the filtering and the attended resolution. The obtained images were in good agreement with numerical simulations reproducing the experimental configuration. Our method offers several advantages such as efficiency, simplicity and rapidity. It underlines that optical near-field

Spatial Rabi oscillations between Majorana bound states and quantum dots

• Jun-Hui Zheng,
• Dao-Xin Yao and
• Zhi Wang

Beilstein J. Nanotechnol. 2018, 9, 1527–1535, doi:10.3762/bjnano.9.143

• from different particle and hole wave functions, μ and ν, for the Andreev bound states. We present numerical simulations for the hybrid system in Figure 2. First, we show the largest oscillation amplitude on the quantum dot as a function of the driving energy ω in Figure 2a, where the scenario for

• electron and hole component T, due to the self-conjugateness of the Majorana bound states. Numerical simulations of the Rabi oscillations. (a) The maximum Rabi oscillation amplitude measured by the occupation probability of the quantum dot, as a function of the driving energy, where the two peaks marks the

Tailoring polarization and magnetization of absorbing terahertz metamaterials using a cut-wire sandwich structure

• Hadi Teguh Yudistira,
• Shuo Liu,
• Tie Jun Cui and
• Han Zhang

Beilstein J. Nanotechnol. 2018, 9, 1437–1447, doi:10.3762/bjnano.9.136

• example that presented by Chen [19] who described a perfect metamaterial absorber based on the interference theory. He demonstrated numerical simulations and analytical calculations of the metamaterial absorber. The design of the metamaterial absorber comprised two parts: a metallic plane, which serves as

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• simulation results. Furthermore, additional artifacts are observed due to an undesired influence on the z feedback controller and on the photodiode of the beam-deflection system in case of light modulation. Results and Discussion Simulations Numerical simulations of the cantilever motion were performed using

• -detection voltage and VCPD the contact potential difference. In our numerical simulations, no z feedback is considered and the z position of the cantilever tip is only influenced by electrostatic forces. This was done in order to focus on the effect of the electrostatic forces. To realize time-resolved KPFM

• by an applied modulated bias, by modulated light pulses, or any other modulation that results in a modulation of the sample surface potential. The numerical simulations only consider a slow Kelvin controller that cannot follow the applied bias modulation and therefore measures an average VCPD. With

Imaging of viscoelastic soft matter with small indentation using higher eigenmodes in single-eigenmode amplitude-modulation atomic force microscopy

• Miead Nikfarjam,
• Enrique A. López-Guerra,
• Santiago D. Solares and
• Babak Eslami

Beilstein J. Nanotechnol. 2018, 9, 1116–1122, doi:10.3762/bjnano.9.103

• short theoretical discussion of the key underlying concepts, along with numerical simulations and experiments to illustrate a simple recipe for imaging soft viscoelastic matter with reduced indentation. Keywords: higher eigenmodes; multifrequency AFM; soft matter; viscoelasticity; Introduction Since

• described in previous studies [29] and details can be found in the computational code provided in [26]. Experimental results Polystyrene thin film height measurements were performed using the same imaging modes as in the numerical simulations. All three measurements were performed with a single cantilever

• polymer film was scratched off from the substrate to provide a reference for the thickness measurements. All of the measurements were performed on the same location on the polymer sample and the results are provided in Figure 3. As in the numerical simulations, AM-AFM with the second eigenmode led to the

A simple extension of the commonly used fitting equation for oscillatory structural forces in case of silica nanoparticle suspensions

• Sebastian Schön and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2018, 9, 1095–1107, doi:10.3762/bjnano.9.101

• , roughness [37] and or potential [38], or addition of varying surfactants [39]. Oscillatory structural forces can be described either theoretically via the solutions of numerical simulations [34][40][41][42] or statistical mechanics equations [43][44][45][46][47][48][49][50] or with a semi empirical approach

Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers

• Yaroslav I. Derikov,
• Georgiy A. Shandryuk,
• Raisa V. Talroze,
• Alexander A. Ezhov and
• Yaroslav V. Kudryavtsev

Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58

• hydro- and organosols with the data of numerical simulations of the surface plasmon resonance, we find that nanoparticles do not aggregate and confirm the transmission electron microscopy data regarding their shape and size. The proposed approach can be effective in preparing hybrid composites without

Study of the vertically aligned in-plane switching liquid crystal mode in microscale periodic electric fields

• Artur R. Geivandov,
• Mikhail I. Barnik,
• Irina V. Kasyanova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2018, 9, 11–19, doi:10.3762/bjnano.9.2

• grating period can result in significant increase of switching speed compared to the traditional LC modes, where the bulk relaxation dominates in electrooptical response. We have studied thoroughly the conditions defining the surface mode applicability. The numerical simulations are in good agreement with

• important. All these problems are new and they are addressed in detail in this work. We show the results of our study of a new VA-IPS surface mode featuring fast switching. The experimentally obtained data are discussed together with results of numerical simulations. The experimental data and simulation

• index modulation is higher in the E7 LC cell, which can result in higher light leakage into the first and higher diffraction orders. The impact of the diffraction can also explain the higher values of transmittance we obtained by numerical simulations (see below in Figure 12) in comparison with the

Material discrimination and mixture ratio estimation in nanocomposites via harmonic atomic force microscopy

• Weijie Zhang,
• Yuhang Chen,
• Xicheng Xia and
• Jiaru Chu

Beilstein J. Nanotechnol. 2017, 8, 2771–2780, doi:10.3762/bjnano.8.276

• alternation of tip–sample interaction forces and thus different harmonic responses. The numerical simulations of the cantilever dynamics were well-correlated with the experimental observations. Owing to the deviation of the drive frequency from the fundamental resonance, harmonic amplitude contrast reversal

• forces and contact time are not directly accessible in experiments. On the contrary, they can be exported for further analysis in numerical simulations if necessary. Effect of drive frequency The higher harmonic amplitudes in our experiments are analyzed with a lock-in amplifier at the integer multiples

Exploring wear at the nanoscale with circular mode atomic force microscopy

• Olivier Noel,
• Aleksandar Vencl and
• Pierre-Emmanuel Mazeran

Beilstein J. Nanotechnol. 2017, 8, 2662–2668, doi:10.3762/bjnano.8.266

• the normal load and the sliding distance and the inverse of the hardness of the material [11]. Exploring wear at the nanoscale becomes more and more mandatory with the development of the nanotechnology and its applications [12]. In addition, emerging numerical simulations of nanowear mechanisms are

Material property analytical relations for the case of an AFM probe tapping a viscoelastic surface containing multiple characteristic times

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

Beilstein J. Nanotechnol. 2017, 8, 2230–2244, doi:10.3762/bjnano.8.223

• excitations. The derivations offered have been thoroughly validated through numerical simulations. Despite the complexities inherent to the intermittent-contact nature of the technique, the analytical findings highlight the potential feasibility of extracting meaningful viscoelastic properties with this

• the physical quantities governing the observables. Methods: Numerical Simulations To model the dynamics of the cantilever, a system of three ordinary differential equations is used, in which each equation corresponds to one eigenmode of the cantilever (assuming the dynamics are mainly contained in the

• reader follow the analytical derivations. It also contains information related to the viscoelastic material that was used in the numerical simulations. Acknowledgements The authors gratefully acknowledge support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award

High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

• Alfredo J. Diaz,
• Hanaul Noh,
• Tobias Meier and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 2069–2082, doi:10.3762/bjnano.8.207

• ), contact-resonance force microscopy (mechanical properties), and SEM combined with a variety of stress-strain AFM experiments and AFM numerical simulations (internal structure). We further study the nanoclay’s response to the application of pressure with multifrequency AFM and conductive AFM, whereby

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls

• Carlos Angulo Barrios and
• Víctor Canalejas-Tejero

Beilstein J. Nanotechnol. 2017, 8, 1231–1237, doi:10.3762/bjnano.8.124

• . This hollow metal configuration features optical resonance as revealed by spectral reflectance measurements and numerical simulations. The fabricated nanocages were demonstrated as a refractometric sensor with a measured bulk sensitivity of 327 nm/refractive index unit (RIU). The pattern design

Scaling law to determine peak forces in tapping-mode AFM experiments on finite elastic soft matter systems

• Horacio V. Guzman

Beilstein J. Nanotechnol. 2017, 8, 968–974, doi:10.3762/bjnano.8.98

• bidimensional deformation contact mechanics model. The equation enables to estimate the peak force based on the tapping mode observables, probe characteristics and the material properties of the sample. The accuracy of the equation has been verified by comparing it to numerical simulations for the archetypical

• posteriori basis. Moreover, those methods could be very time consuming to tune for non-expert enthusiastic AFM experimentalists and their accuracy is under debate within the dynamic AFM community [16][17]. Numerical simulations and analytical scaling laws are well-established methods to estimate the

• building a one-variable regression of k then continues with Q, Reff and finally Eeff. These multiple regressions were based on the numerical simulations results for the operational, probe and materials properties values given in Table 1, letting, with a cumulative coefficient of determination of R2 ≈ 0.85

Functional dependence of resonant harmonics on nanomechanical parameters in dynamic mode atomic force microscopy

• Federico Gramazio,
• Matteo Lorenzoni,
• Francesc Pérez-Murano,
• Enrique Rull Trinidad,
• Urs Staufer and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 883–891, doi:10.3762/bjnano.8.90

• from the tip. Thus, by combining Equation 2 and Equation 3 it is possible to determine the dependence of An as a function of all relevant parameters. However, An can be hardly solved analytically, so that numerical simulations are required. On the other hand, the dynamics of the oscillating cantilever

• increase in tip radius. Note the higher A6 values in Figure 7b, as compared to those in Figure 7a for similar A1 values. This is essentially due to the softer cantilevers used in Figure 7b, an effect described in Figure 3. Conclusion Based on numerical simulations using the VEDA code we have proposed a

Modeling of the growth of GaAs–AlGaAs core–shell nanowires

• Qian Zhang,
• Peter W. Voorhees and
• Stephen H. Davis

Beilstein J. Nanotechnol. 2017, 8, 506–513, doi:10.3762/bjnano.8.54

• can be found in [7][10][11][12]. Different from the focus of [9], in [7], we did a systematical theoretical analysis and numerical simulations for the case shown in Figure 2. Here, in order to determine the influence of diffusion and deposition on the morphological evolution of the shell, consider

Zigzag phosphorene nanoribbons: one-dimensional resonant channels in two-dimensional atomic crystals

• Carlos. J. Páez,
• Dario. A. Bahamon,
• Ana L. C. Pereira and
• Peter. A. Schulz

Beilstein J. Nanotechnol. 2016, 7, 1983–1990, doi:10.3762/bjnano.7.189

• by the arrow 2 in panel (b). Acknowledgements CJP and ALCP acknowledge FAPESP, grant 2012/19060-0. DAB acknowledges support from FAPESP grant 2012/50259-8. PAS acknowledges support from CNPq. Numerical simulations were performed at cluster LaSCADo-UNICAMP, supported by FAPESP under project 2010

Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy

• Patrick Philipp,
• Lukasz Rzeznik and
• Tom Wirtz

Beilstein J. Nanotechnol. 2016, 7, 1749–1760, doi:10.3762/bjnano.7.168

• profiling; helium ion microscopy; ion bombardment; numerical simulations; polymers; SDTRIMSP; Introduction Ion bombardment of polymer samples has been studied for various applications related to surface modifications and surface analysis. Ion bombardment of polymers allows to change the electric

Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

• Austin Deschenes,
• Sadid Muneer,
• Mustafa Akbulut,
• Ali Gokirmak and
• Helena Silva

Beilstein J. Nanotechnol. 2016, 7, 1676–1683, doi:10.3762/bjnano.7.160

• magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. In this work we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical

• simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the

Dynamic of cold-atom tips in anharmonic potentials

• Tobias Menold,
• Peter Federsel,
• Carola Rogulj,
• Hendrik Hölscher,
• József Fortágh and
• Andreas Günther

Beilstein J. Nanotechnol. 2016, 7, 1543–1555, doi:10.3762/bjnano.7.148

• closes with a conclusion and a methods section, describing the details of the numerical simulations. Theory of tip dynamics The dynamics of a cold-atom tip in an anharmonic potential is fundamentally different from the dynamics of a conventional solid-state tip. While the solid tip behaves like a rigid

Localized surface plasmons in structures with linear Au nanoantennas on a SiO₂/Si surface

• Ilya A. Milekhin,
• Sergei A. Kuznetsov,
• Ekaterina E. Rodyakina,
• Alexander G. Milekhin,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2016, 7, 1519–1526, doi:10.3762/bjnano.7.145

• , 1400, and 1900 nm chosen for practical implementation were used in numerical simulations. The listed nanoantenna lengths (1400 and 1900 nm) secure the proximity of ther LSPR energy to the energy of optical phonons in SiO2. For the fixed structural parameters of the nanoantenna array, the simulations

• characteristic length h0 of the allometric function alteration changes within 12.9–30.0 nm. The latter values are assessed to be in good concordance with the LSPR localization depth δLSPR and the “two exponents fit” established by us in numerical simulations. It is important to highlight that the influence of

The self-similarity theory of high pressure torsion

• Yan Beygelzimer,
• Roman Kulagin,
• Laszlo S. Toth and
• Yulia Ivanisenko

Beilstein J. Nanotechnol. 2016, 7, 1267–1277, doi:10.3762/bjnano.7.117

• numerical simulations show that the true plastic flow during HPT can differ significantly from the theoretical predictions given by the simple scheme above. In particular, in [4][5] a problem of coupled phase transformations and plastic flows under torsion at high pressure in a rotational diamond anvil cell

• physical cause of self-similarity at the macro-level. Results of numerical simulations In subsection 2 of the section “Model” it has been shown that if the hardening law of the material has a power-law form, the HPT process must evolve in a self-similar fashion, and its parameters must have a power

• ). Finally, for shear stress and torque, the exponent is equal to the exponent of the hardening law (see Equation 39 and Equation 40). The second-order differential Equation 32 cannot be solved analytically. Therefore, numerical simulations are needed to identify self-similar solutions. In this section, we

Functional diversity of resilin in Arthropoda

• Jan Michels,
• Esther Appel and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1241–1259, doi:10.3762/bjnano.7.115

• hypothesis is difficult to test experimentally using biological specimens, it was tested using numerical simulations [49] (Figure 2D–F). The results indicate that setae with long soft tips and rigid bases exhibit a strong adhesion but also a pronounced clusterisation (Figure 2E). Setae with rigid tips and