Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing

• Hongzhou Li and
• Jialian Chen

Beilstein J. Nanotechnol. 2021, 12, 213–221, doi:10.3762/bjnano.12.17

• cannot be controlled. There are no reliable theoretical or experimental methods to evaluate the mechanical behavior during nanoindentation of an elastic–plastic microsphere. Therefore, it is necessary to conduct reliable numerical simulations to evaluate this behavior. This article reports a systematic

• the mechanical behavior during nanoindentation of a curved specimen. Therefore, it is necessary to conduct reliable numerical simulations to evaluate the mechanical behavior of nanoindentation on an elastic–plastic microspherical material. The numerical simulations are usually carried out via the

• behavior of microspherical materials and to reduce the number of experimental tests, finite element simulations are used to calculate the load–displacement curves of nanoindentation during loading and unloading. The unloading curve is used to determine the elastic modulus of a material via the well-known

TiO_x/Pt₃Ti(111) surface-directed formation of electronically responsive supramolecular assemblies of tungsten oxide clusters

• Marco Moors,
• Yun An,
• Agnieszka Kuc and
• Kirill Yu. Monakhov

Beilstein J. Nanotechnol. 2021, 12, 203–212, doi:10.3762/bjnano.12.16

• experimental evidence of these species by external charge injection. Theoretically interesting are also under-coordinated W3O9 derivatives, such as W3O8 with CS symmetry, in which one of the tungsten centers has only one terminal oxygen atom instead of two. From simulations it is known that such a tri

• calculated values based on the used deposition rate. Tests with a varied deposition rate showed no significant impact on the cluster adsorption behavior. Density functional theory simulations The simulations of W3O9 and W3O8 clusters were performed using the AMS suite [31]. The geometry optimization and

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

• Sciences (CAS), Suzhou 215123, China CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China 10.3762/bjnano.12.7 Abstract We study the oscillatory behavior of qPlus sensors with a long tilted tip by means of finite element simulations

• the optimal diameter was found to be 0.1 mm. Keywords: finite element method; long tilted tip; noncontact atomic force microscopy; qPlus sensor; quartz tuning fork; simulations; Introduction Quartz tuning forks are widely used in the watch industry because of their low frequency offset over a wide

• rectangular drop of Torr seal epoxy. The diameter values of the tungsten tip used in the simulations were chosen according to diameters of the tungsten wire available [24]. We selected four different diameters: 0.025 mm, 0.05 mm, 0.075 mm, and 0.1 mm. The tip length can be customized according to the

The role of gold atom concentration in the formation of Cu–Au nanoparticles from the gas phase

• Yuri Ya. Gafner,
• Svetlana L. Gafner,
• Darya A. Ryzkova and
• Andrey V. Nomoev

Beilstein J. Nanotechnol. 2021, 12, 72–81, doi:10.3762/bjnano.12.6

• by Dr. Ralf Meyer at the University of Duisburg (Germany), was used for the MD simulations. Results and Discussion During the simulation of the condensation process of copper and gold atoms, the temperature in the synthesis region was determined by two independent factors: the cooling process of the

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• range of applications to thin sections, similar to the transmission option in SEMs. In combination with the well-established heavy-metal staining techniques used in transmission electron microscopy (TEM), this would allow for ultrastructural research comparable to standard TEM. SRIM [57] simulations

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

• channeling effect in the HIM has also been studied using Monte Carlo [21] and molecular dynamics [22] simulations. Measuring the energy of the transmitted particles is a novel technique that adds an information channel to the previously discussed transmission imaging modes. It will provide information on the

•  3b, we show simulations of the exit angular distribution of 30 keV He for the different stacks of materials that are present in the sample, using TRIDYN [39] in static mode. The graph presented in Figure 3b shows the corresponding transmission angular distribution for the region used in Figure 3a

• . The expected contrast between different areas of the sample for the detection range of 0 to 4.5° is calculated from these distributions. In Table 1, a comparison between the contrast calculated in the simulations and the contrast obtained from Figure 3a is given. For this sample, the simulated and

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• folded 2D material. In principle, the model describes any 2D material, and its predictions are corroborated by comparison with classical molecular dynamics simulations and to results of previous investigations on graphene and talc. Because folds naturally occur in flakes of varying thickness

• geometries for folded edges in a graphene monolayer (Figure 2a) and in three-layered graphene (Figure 2b), obtained through MD simulations (details about MD simulations are found in Supporting Information File 1). As can be seen in Figure 2a, the model geometry consists of a sequence of straight lines and

• the particular case of the folded edge in a graphene monolayer shown in Figure 2a, we used literature values for α = 0.37 N/m [30] and κ = 0.231 aJ [35] to determine r0 and R0. In the case of the folded edge in three-layered graphene, we used values of R0 = 0.81 nm and d0 = 1.01 nm from MD simulations

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• intrinsic layer allows one to meet the required electrical specifications for switches in power electronics. In order to analyse the profiles extracted from the sMIM measurements, the majority carrier concentration calculated by numerical simulations [31] for an abrupt PIN doping profile is compared with

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• compared with ion beams such as lithium, beryllium, boron, and silicon, obtained from a mass-separated FIB using a liquid metal alloy ion source (LMAIS) with respect to the imaging and milling resolution, as well as the current stability. Simulations were carried out to investigate whether the

• experimentally smallest ion-milled trenches are limited by the size of the collision cascade. While He+ offers, experimentally and in simulations, the smallest minimum trench width, light ion species such as Li+ or Be+ from a LMAIS offer higher milling rates and ion currents while outperforming the milling

• imaging resolution and minimum milling width were compared with those of helium and neon beams provided by a GFIS-driven HIM system. According to our simulations and experiments, the imaging and milling resolution of all systems is determined by the ion beam profile and the stability of the ion beam and

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• doping parameters. These results are in good agreement with numerical simulations of the doping process applied to silicon nanowires. These devices, based on doped nanowire forests, offer a possible route for the exploitation of the high power factor of silicon, which, combined with the very low thermal

• . Therefore, it is mandatory to perform a single-step diffusion process, which results in a nonuniform doping concentration in the nanowire. Here, we report the measurement of the Seebeck coefficient after different doping processes, and compare the measurements with numerical simulations that take into

• consideration the nonuniform doping of the silicon nanowires. We found a very good agreement between experimental measurements and simulations of the doping process. Methods Fabrication and doping of silicon nanowire forests Silicon nanowire forests have been fabricated by a simple and inexpensive process based

Out-of-plane surface patterning by subsurface processing of polymer substrates with focused ion beams

• Serguei Chiriaev,
• Luciana Tavares,
• Vadzim Adashkevich,
• Arkadiusz J. Goszczak and
• Horst-Günter Rubahn

Beilstein J. Nanotechnol. 2020, 11, 1693–1703, doi:10.3762/bjnano.11.151

• Information SRIM simulations of collision and ionization in 5 nm Pt60Pd40/200 nm PMMA samples irradiated with He+, Ne+, and Ga+ FIBs. Supporting Information File 144: SRIM simulations. Funding Partfunding from Interreg Deutschland-Danmark within the European Regional Development Fund (ERDF) via the CELLTOM

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• value of the coaxial cable to the combined terminations of the channels 3,4 is Cch3,4 = 110 pF. The cell resistance values, Rcell, used for the SPICE simulations are listed in Table 2. Figure 6b shows the simplified circuit model in which the parasitic capacitances and termination resistances for both

• , Ramorphous(after-pulse), (Figure 6c) for the two re-amorphization events shown in Figure 4. The Rmolten value is assumed to be 140 Ω for all simulations, which is slightly less than the Rcrystalline value, since melting incorporates a drop in the GST resistivity [26]. Table 2 lists these different resistance

• values used for the circuit simulations. Melting and re-amorphization of a GST cell is simulated with three switches S1, S2, and S3 that sequentially turn on and off to include the appropriate Rcell (Figure 6c). For both re-amorphization cases, the melting is assumed to take place when Vch3,4 starts to

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• structure of complex molecular adsorbates from microscopy images can be difficult, and using atomistic simulations to find the most stable structures is limited to partial exploration of the potential energy surface due to the high-dimensional phase space. In this study, we present the recently developed

• Bayesian Optimization Structure Search (BOSS) method as an efficient solution for identifying the structure of non-planar adsorbates. We apply BOSS with density-functional theory simulations to detect the stable adsorbate structures of (1S)-camphor on the Cu(111) surface. We identify the optimal structure

• surface structures, but interpreting images of bulky three-dimensional molecules on surfaces can be difficult, which prevents an accurate structure determination. In such cases, computations can help in detecting the most stable structures. With atomistic simulations, we can determine the optimal

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• at the trapping voltage of each particle. For the simulations, a conductivity of 21.3 µS·cm−1 and a relative permittivity of 78.4 for the suspension medium were used, while the substrate was assumed to be an insulator due to the low conductivity of PDMS [58]. The nonlinear empirical electrophoretic

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• -shaped cantilevers in multifrequency, specifically bimodal, AFM. The optimum geometrical dimensions of V-shaped cantilevers that can provide maximum phase contrast (material composition) are found by simulations. The effect of geometry on static and dynamic parameters of cantilevers such as mass, spring

• of Zc = 6 nm on Au is provided. In this round of simulations, the parameters were L = 85 µm, = 15 µm, bref = 86 µm, tref = 0.4 µm, Rtip = 9 nm, and α = 0° where α is defined as the angle between the cantilever and sample. Since this angle cannot be controlled by the user in AFM experiments, it is

• assumed that the cantilever is parallel to the surface for all simulations and experiments of this work. These results verify that the simulation can capture weakly perturbed oscillations of the V-shaped cantilevers in bimodal AFM. It should also be mentioned that the oscillation amplitudes for the first

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• . During subsequent adsorption studies the molecule and the first CoO bilayer were allowed to relax. Calculations were carried out with an energy cutoff of 400 eV and at the gamma point only, all structures were relaxed until forces were smaller than 0.1 eV/Å. STM simulations were performed employing the

• activation energy of rotational motion is below 200 meV. The orientation is given as the angle of the molecular axis with respect to the direction of the Ir(100) surface. (d, e) Top and side view, respectively, of 2 on 1BL CoO. Insets in (a) and (d) are STM-DFT simulations at bias voltages of −1.6 V and

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• geometry of the molecules from which they are emitted [28]. The experimental maps in Figure 3a and Figure 3b are in very good agreement with the simulations of the HOMO and LUMO for 6P having two orthogonal orientations. The observation of the LUMO emission clearly shows that charge transfer has occurred

• intensity used in the following angle-resolved ultraviolet photoemission spectroscopy experiments is marked with crosses. Deviations from the simulations for isolated molecules are a result of MgO and Ag(100) sp-band emissions. Films of 6P were grown and measured at room temperature. He I ARUPS spectra for

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• allows the determination of the electronic properties of the pyrene adsorbates by STM and STS", and the comparison with the gaps estimated by theoretical simulations in vacuum and by UV-vis spectroscopies in solution. Remarkably, the electronic states of the pyrene adsorbates near the Fermi level, probed

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• Figure 2e) evolve on one side of a sharp line connecting the weights of the dumbbells. For an interpretation of the NC-AFM contrast, we run simulations based on the probe particle model [23] for three molecules aligned along , each molecule being in the DFT-optimised adsorption geometry geo 1 [22], as

• similarity to the experimental data. The change from the ellipse to the dumbbell shape is reproduced as well as the evolution of a sharp line connecting the two dumbbell weights (Figure 2h,l). The characteristic contrast features appear in the simulations at different heights for the different tips, a

• is in turn caused by attractive forces acting between the tip and other atoms of the FDCA molecule. Thus, the PPM simulations allow for the assignment of the dumbbell shape to a single FDCA molecule and, in turn, the orientation of the dumbbell precisely defines the axis between the top hydrogen

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

• viscoelastic properties). To obtain further insight, we now examine the force trajectories for the above simulations, which are shown in Figure 4 for an amplitude setpoint of approximately 55% (in the repulsive branch). Figure 4a confirms that the indentation is ca. 1.9 nm greater for material 1 than for

• calculation using Equation 2 and Equation 4 shows that the storage and loss moduli of material 2 have increased by factors of approximately 4.9 and 3.7, respectively. The above simulations illustrate the frequency dependence of the AFM observables for specific materials, along with the challenges involved in

• approach can help to avoid some of the mischaracterization issues discussed above, especially in combination with numerical simulations of quasi-static [14][33][34] and dynamic AFM [35] measurements, which incorporate viscoelastic models such as those depicted in Figure 1. Conclusion We have presented an

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• mode v1.61. The laser correlation spectrometer was equipped with a multi-computing correlator type 7032 CE. Simulation of spatial structure of γ-Fe2O3 nanoparticles coated with blood plasma protein biocorona Simulations of biocorona formation at the surface of γ-Fe2O3 nanoparticles were performed using

• structure of a maghemite nanoparticle coated with blood plasma protein biocorona Interaction of the nanoparticles and plasma proteins was also analyzed with computer modeling and simulations of spatial structures using the programs LeadIT 2.3.2, ArgusLab 4.0.1 and Material Science Suite 2015, and the online

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• of the H-terminated Si(100)-2 × 1 surface, its structural features, and defects. Six different scanning probe imaging modes are performed using both STM and nc-AFM. By combining the accessible information with probe particle simulations [23][24] (presented in Supporting Information File 1) of the

• structure negatively charged. We demonstrate the tip-induced removal of the weakly bound H atom, leaving the site neutral. While we present an extensive experimental analysis supplemented with simple simulations of common surface defects on H-terminated silicon, we anticipate that the provided assignments

• stronger repulsive component is observed for the more inert H-functionalized tip probing the H-atom (bright contrast), while the more reactive Si-terminated tip (dark contrast) leads to a stronger attractive interaction (more negative Δf) at the same site [39][40][41][43][44][45]. Simulations of the STHM

Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

• Sergey Bakurskiy,
• Mikhail Kupriyanov,
• Nikolay V. Klenov,
• Igor Soloviev,
• Andrey Schegolev,
• Roman Morari,
• Yury Khaydukov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1336–1345, doi:10.3762/bjnano.11.118

• transitions of individual superconducting layers (or groups of layers) in the multilayer structure. As explained previously in the simulations (Figure 2 and Figure 3), the effective critical temperature of the s-layers within the multilayer structure (i.e., the temperature in which the superconducting order

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• , whereas the volatile products ones are pumped out of the process chamber. Normally, the final deposit is a mixture of carbon, metallic elements and oxygen. As clearly described using analytical modelling [29] and Monte-Carlo simulations [30], the vertical growth of 3D nano-objects by He+ FIBID is mainly