Oblique angle deposition of nickel thin films by high-power impulse magnetron sputtering

• Hamidreza Hajihoseini,
• Movaffaq Kateb,
• Snorri Þorgeir Ingvarsson and
• Jon Tomas Gudmundsson

Beilstein J. Nanotechnol. 2019, 10, 1914–1921, doi:10.3762/bjnano.10.186

• show a well-defined inclined growth, although some grains are elongated toward the incoming flux. The angle between columnar grains and substrate normal (β) is different and generally smaller than the angle between the substrate normal and the target (α). Both experimental results [38] and simulations

Long-term entrapment and temperature-controlled-release of SF₆ gas in metal–organic frameworks (MOFs)

• Hana Bunzen,
• Andreas Kalytta-Mewes,
• Leo van Wüllen and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2019, 10, 1851–1859, doi:10.3762/bjnano.10.180

• included powder X-ray diffraction measurements, thermogravimetric analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, 19F nuclear magnetic resonance spectroscopy and computational simulations. In addition, the possibility to release the gas guest by applying elevated

• of a guest released from a porous material. The determined value of the activation energy was further compared to the results obtained from computational simulations (see the dedicated section later in the text). To qualify the guest, we used FTIR spectroscopy (Figure 2 and Figure S5 in Supporting

• simulations Theoretical calculations were performed in order to determine the activation energy parameters from atomistic simulation data. Briefly, the approach previously described for scanning the minimum energy path of xenon atoms crossing the small pore in MFU-4 [13] was adapted and further refined in

Stationary beam full-field transmission helium ion microscopy using sub-50 keV He⁺: Projected images and intensity patterns

• Michael Mousley,
• Santhana Eswara,
• Olivier De Castro,
• Olivier Bouton,
• Nico Klingner,
• Christoph T. Koch,
• Gregor Hlawacek and
• Tom Wirtz

Beilstein J. Nanotechnol. 2019, 10, 1648–1657, doi:10.3762/bjnano.10.160

• The THIM instrument shown schematically in Figure 1 was used to acquire the THIM images of BN nanoparticles adhered to a TEM grid as shown in Figure 2. A video was recorded while varying the Lens 2 voltage (which sets the ion beam focal point) from approximately 5 kV to 9 kV. Simulations with SIMION

• deflection. It will be a combination of the charging rate, focal plane position and natural charge fluctuations that determines the spot positions observed at each Lens 2 voltage. Future work on understanding these patterns could include simulations of predicted intensity from more basic systems such as

• individual insulating spherical particles on a metal grid. Simulations would allow easier control of the structure of the particle compared to experiments and could yield useful insights related to the role of sample morphology on the intensity redistribution. While the spot patterns observed in this work

Subsurface imaging of flexible circuits via contact resonance atomic force microscopy

• Wenting Wang,
• Chengfu Ma,
• Yuhang Chen,
• Lei Zheng,
• Huarong Liu and
• Jiaru Chu

Beilstein J. Nanotechnol. 2019, 10, 1636–1647, doi:10.3762/bjnano.10.159

• sample properties was systematically investigated by combining experimental results with theoretical analysis from finite element simulations. The results show that imaging with a softer cantilever and a lower eigenmode will improve the subsurface contrast. The experimental results and theoretical

• the same as that in the analytical calculations. Since the model is axisymmetric, we used the two-dimensional FEA simulations for simplicity. The width of the sample was set to 2 µm and the thickness of the silicon substrate was 10 µm. Mesh refinement was applied near the tip–sample contact area. The

• images at the applied force of 132, 303, 360, 589, and 646 nN, respectively, using the PPP-FM cantilever. (f) The obtained contact stiffness contrast as a function of normal force from the experiments, theoretical calculations and FEA simulations. Influence of cantilever stiffness on CR-AFM subsurface

Effects of surface charge and boundary slip on time-periodic pressure-driven flow and electrokinetic energy conversion in a nanotube

• Mandula Buren,
• Yongjun Jian,
• Yingchun Zhao,
• Long Chang and
• Quansheng Liu

Beilstein J. Nanotechnol. 2019, 10, 1628–1635, doi:10.3762/bjnano.10.158

• independent of the surface charge. However, recent theoretical and experimental results have shown that the surface charge affects the slip length. Joly et al. [18] used molecular dynamics simulations to find the relationship between slip length and surface charge density. The reason is that there exists an

Graphynes: an alternative lightweight solution for shock protection

• Kang Xia,
• Haifei Zhan,
• Aimin Ji,
• Jianli Shao,
• Yuantong Gu and
• Zhiyong Li

Beilstein J. Nanotechnol. 2019, 10, 1588–1595, doi:10.3762/bjnano.10.154

• performance as well as the number of broken bonds. Results and Discussion The fracture behavior and mechanical performance of GYs, including α-, β-, γ- and 6612-GY under supersonic-velocity impact were assessed through a series of large-scale MD simulations performed using the open-source package LAMMPS [30

• linkages tends to have a lower number of breaking bonds, which means the presence of acetylenic linkages makes the material less brittle. Additionally, we conducted additional simulations by varying the time step from 0.1 to 0.5 fs from which the same results are obtained (see Section S5 of Supporting

• higher elastic wave propagation velocity, it tends to transfer momentum at a faster rate. Thus, a better energy dissipation or delocalization is expected during impact. According to the simulations under impact velocity values from 1 to 6 km/s, it is observed that a higher impact velocity will induce

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• . Interestingly, sufficiently high binding constants were confirmed even when the hydrogen bonding sites were exposed to the high-dielectric medium at the very vicinity of the low-dielectric medium. These simulations hint at the mechanism of enhanced molecular recognition at these interfaces. The non-polar phase

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• simulations based on the Bloch wave method [27]. Both X-ray diffraction pattern (XRD) and intensity profile of the SAED (Figure 1c) reveal that the as-synthesized sample crystallizes into an orthorhombic russellite phase (PDF#79-2381) with space group Pca21 (no. 29). The refined lattice parameters are a

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

• in both experiments and simulations [21][22][23], the examination of this surface with dynamic AFM will allow for verification that both FFM and CR modes can be used to capture atomic-scale variations in mechanical properties. Furthermore, examining the mechanical properties of the HOPG surface can

• topographical variation. Beyond the contact stiffness, the elastic modulus of HOPG has been investigated in both experiments and simulations [41]. The reported values range between 17 GPa [42] to 60 GPa [43]. The drastic change in the reported values depend on the employed methodology and scale of the

• by simple rigid-body geometry. Comparison between the simulation results and the rigid body model suggested that increased elastic deformation of the step as the tip scanned over the step edge resulted in the increased step width observed in the simulations compared to that predicted by the rigid

Fabrication of phase masks from amorphous carbon thin films for electron-beam shaping

• Lukas Grünewald,
• Dagmar Gerthsen and
• Simon Hettler

Beilstein J. Nanotechnol. 2019, 10, 1290–1302, doi:10.3762/bjnano.10.128

• = 1 beam for the saw-tooth shaped PM. Consistency with theory was examined by accompanying simulations with a self-written MATLAB program for the first few diffraction orders for sinusoidal and saw-tooth shaped thickness patterns (Figure 8b,c). As the displayed VBs form in the far-field Fraunhofer

• varying intensity. The size of the doughnut-shaped beam profile increases with the topological charge l. Magnified sections for l = −2 to l = 2 for (b) sinusoidal and (c) saw-tooth patterns with linear intensity scale are compared with simulations. (b) The sinusoidal pattern shows good agreement, whereas

• 2.7 µm by 2.7 µm. The playback speed of Supporting Information File 1 and Supporting Information File 2 corresponds to 7 mm defocus per second. The playback speed of Supporting Information File 3 corresponds to 3.5 mm defocus per second. Supporting Information File 4 contains accompanying simulations

On the relaxation time of interacting superparamagnetic nanoparticles and implications for magnetic fluid hyperthermia

• Andrei Kuncser,
• Nicusor Iacob and
• Victor E. Kuncser

Beilstein J. Nanotechnol. 2019, 10, 1280–1289, doi:10.3762/bjnano.10.127

• static and time-dependent micromagnetic simulations. Keywords: magnetic hyperthermia; magnetic nanoparticles; magnetic relaxation time; micromagnetic simulation; Introduction Magnetic relaxation phenomena in nanoparticulate systems are under intensive investigation today, especially due to their

• measurements and (iii) to provide theoretical support for the specific evolution of the relaxation time constant and the anisotropy energy barrier in the Néel expression as function of interparticle interaction through a suitable exploitation of static and time-dependent micromagnetic simulations. Results and

• also shows two theoretical simulations according to the numerical solution of Equation 6 involving the Rosensweig model for power P* (Equation 4) with the above-mentioned input parameters and for two different time constants: τ0 = 3.4 × 10−9 s and 1.2 × 10−9 s. The first time constant corresponds to

Imaging the surface potential at the steps on the rutile TiO₂(110) surface by Kelvin probe force microscopy

• Masato Miyazaki,
• Huan Fei Wen,
• Quanzhen Zhang,
• Yuuki Adachi,
• Jan Brndiar,
• Ivan Štich,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2019, 10, 1228–1236, doi:10.3762/bjnano.10.122

• structure, which implies that and have a different CPD. To measure this difference a high measurement resolution is required. To corroborate the our assumptions, we performed DFT simulations and calculated the local electrostatic potential for four different step configurations, , , reduced , and , see

Electroluminescence and current–voltage measurements of single-(In,Ga)N/GaN-nanowire light-emitting diodes in a nanowire ensemble

• David van Treeck,
• Johannes Ledig,
• Gregor Scholz,
• Jonas Lähnemann,
• Mattia Musolino,
• Abbes Tahraoui,
• Oliver Brandt,
• Andreas Waag,
• Henning Riechert and
• Lutz Geelhaar

Beilstein J. Nanotechnol. 2019, 10, 1177–1187, doi:10.3762/bjnano.10.117

• decisive for the comparison of device simulations as reported in [7] with experimental results for NW LEDs. Therefore, the measurement technique employed here is a very powerful analysis tool for the investigation of LEDs based on NW ensembles and provides new opportunities for their detailed study. (a

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• binding energy in the QW [50]. To compare the experimental data with predictions from the simple QD confinement simulations, Figure 5 shows the first (lowest energy) transition energy as a function of R for the QD (for simplicity, we approximate the QD shape as spherical, as indicated in the inset to

Influence of dielectric layer thickness and roughness on topographic effects in magnetic force microscopy

• Alexander Krivcov,
• Jasmin Ehrler,
• Marc Fuhrmann,
• Tanja Junkers and
• Hildegard Möbius

Beilstein J. Nanotechnol. 2019, 10, 1056–1064, doi:10.3762/bjnano.10.106

• the probe resulting in an attractive force. In contrast, the electrostatic force due to topography changes is a repulsive force. Simulations as well as experiments show that an increase of the dielectric layer thickness between nanoparticle and substrate leads to a decrease of the capacitive coupling

• compares the phase shift due to capacitive coupling of a nanoparticle lying on a flat substrate with the phase shift for a nanoparticle lying on dielectric layers with different layer thicknesses. All simulations were carried out assuming the absence of trapped charges on the dielectric layer. Introducing

• whereas the roughness of layers of several 100 nm thickness has no influence on the MFM phase signal. Although the idealized calculations neglect trapped charges on the dielectric layer the simulations reveal a significant reduction of capacitive coupling using a dielectric layer. Magnetic forces between

Revisiting semicontinuous silver films as surface-enhanced Raman spectroscopy substrates

• Malwina Liszewska,
• Bogusław Budner,
• Małgorzata Norek,
• Bartłomiej J. Jankiewicz and
• Piotr Nyga

Beilstein J. Nanotechnol. 2019, 10, 1048–1055, doi:10.3762/bjnano.10.105

• hypothetical continuous film) of silver is e-beam deposited on a proper adhesion layer (for example silicon dioxide) [43][44]. The results of simulations and experimental studies show that the hot spots exist in SSFs [2][44][45][46][47], and hence they have been extensively studied as SERS substrates [40][41

Experimental study of an evanescent-field biosensor based on 1D photonic bandgap structures

• Jad Sabek,
• Francisco Javier Díaz-Fernández,
• Luis Torrijos-Morán,
• Zeneida Díaz-Betancor,
• Ángel Maquieira,
• María-José Bañuls,
• Elena Pinilla-Cienfuegos and
• Jaime García-Rupérez

Beilstein J. Nanotechnol. 2019, 10, 967–974, doi:10.3762/bjnano.10.97

• are out of the PBG region. Finite-difference time-domain (FDTD) simulations carried out for this configuration of the PBG structure predicted a PBG edge location at ca. 1530 nm, so a deviation of only about 20 nm was observed for the actual fabricated structure, i.e., ca. 1530 nm instead of ca. 1550

• Figure 3). SNOM images in Figure 4a show how the intensity of the evanescent field significantly decreases for heights above 100 nm. FDTD propagation simulations were then also carried out and the evanescent field intensity was calculated for the same heights used in the SNOM measurements, as shown in

• the FDTD simulations shown in Figure 4b, maximum values of the evanescent field intensity over different periods of the PBG structure were obtained. The results are presented in Figure 4c as a function of the distance from the surface. As it can be observed in the graph, a strong exponential decrease

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• Li–S batteries. Simulation Details The same simulation method and models of [26] were used in the present work. All spin-polarized DFT calculations were performed with the Vienna ab initio simulation package (VASP) [42] plane-wave simulations. Electron–ion interaction and electron exchange

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

• frequency shift peak’ (tFP) by Giridharagopal and co-workers [22]. The authors demonstrated that simulated results (both numerical simulations of a damped-driven harmonic oscillator and finite element simulations) and their experimental results show excellent agreement given the same parameters and subject

• FF-trEFM for these measurements, we performed numerical simulations (of a damped driven harmonic oscillator, see Supporting Information File 1 for MATLAB code) similar to those performed by Karatay and co-workers [51], using instead a resonance frequency varying in time as a stretched exponential and

• for excitations with time constants of 25 ns and 100 μs are shown).” Reproduced with permission from [51], copyright 2016 AIP Publishing. Extracted FF-trEFM signals from numerical simulations of tip–sample interactions with a stretched-exponential time response (Equation 1) with various relaxation

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• defect formation mechanisms. The estimations include Monte Carlo simulations for He, Ar, Xe, C, N and Si ions, performed in the incident ion energy range from 100 eV to 250 MeV. Cu, SiO2, SiC and Al2O3 substrates were analyzed. The considered substrate-related defect formation mechanisms are sputtering

• Transport of Ions in Matter (TRIM) simulations using 160 MeV Xe ions for the irradiation of graphene on Cu, SiO2/Si and glass leads to negligible overall participation of substrate sputtering and a stronger (but small) role of the substrate recoils. Besides, it was noted that hot electrons generated in the

• through a simple method of choosing the substrate/ion combination. Due to their nature, 2D materials tend to absorb a small fraction of ion energy in the keV–MeV range [15]. This allows simulations of the bulk substrate effects to be performed independent of the monolayer type. Although not directly

Mechanical and thermodynamic properties of Aβ₄₂, Aβ₄₀, and α-synuclein fibrils: a coarse-grained method to complement experimental studies

• Adolfo B. Poma,
• Horacio V. Guzman,
• Mai Suan Li and
• Panagiotis E. Theodorakis

Beilstein J. Nanotechnol. 2019, 10, 500–513, doi:10.3762/bjnano.10.51

• experimental observations. Keywords: β-amyloid; atomic force microscopy, mechanical deformation; molecular simulation; proteins; α-synuclein; Introduction All-atom molecular dynamics (MD) simulations have been employed to study the physical and chemical behaviour of the fundamental biomolecules of life (e.g

• ., proteins [1], nucleic acids [2] and lipids [3]). Lipid membranes, viral capsids, and biological fibrils are common examples of large complexes that pose significant challenges for all-atom simulations. For example, the time scales of various biological processes are in the range from 10−6 to 10−3 s, and

• thus they are orders of magnitude larger than typical molecular motions (10−15 to 10−12 s) captured in all-atom MD. The length scales are similarly much smaller in all-atom simulations than it would be relevant for studying processes involving large conformational changes in large biological complexes

Polymorphic self-assembly of pyrazine-based tectons at the solution–solid interface

• Achintya Jana,
• Puneet Mishra and
• Neeladri Das

Beilstein J. Nanotechnol. 2019, 10, 494–499, doi:10.3762/bjnano.10.50

• theoretical simulations [24][25][26]. For this purpose, our experimental results with sub-molecular resolution can provide valuable inputs for future theoretical calculations on related molecule–substrate systems. Another possible reason for the observed polymorphism could be attributed to a competition

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• section. OTS molecules are more reactive with –OH groups on the metal oxide surfaces [31][32][33]. Molecular dynamics simulations revealed that the OB site of SnO2 was the most preferable site for the formation of –OH groups [34][35]. Thus, OTS binds dominantly at OB sites over the OP sites of SnO2 NPs

Intuitive human interface to a scanning tunnelling microscope: observation of parity oscillations for a single atomic chain

• Sumit Tewari,
• Jacob Bakermans,
• Christian Wagner,
• Federica Galli and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2019, 10, 337–348, doi:10.3762/bjnano.10.33

• . Looking up the value from the lookup table is faster than calculating it, resulting in better performance. We have compared this speed up in simulation due to the aforementioned approximations with a standard implementation of the MD simulations without any approximations. For this we performed a

• feedback loop from the experimental conductance values, a real-time conductance estimation based on the atomistic positions given by the MD simulations could be useful. Tight-binding models have been known [56] to give a relatively fast (as compared to DFT and other computationally expensive methods

Geometrical optimisation of core–shell nanowire arrays for enhanced absorption in thin crystalline silicon heterojunction solar cells

• Robin Vismara,
• Olindo Isabella,
• Andrea Ingenito,
• Fai Tong Si and
• Miro Zeman

Beilstein J. Nanotechnol. 2019, 10, 322–331, doi:10.3762/bjnano.10.31

• reflectance measured by means of a Perkin Elmer LAMBDA 950 UV–vis–NIR spectrophotometer. Modelling approach Simulations of the radial heterojunction c-Si nanowire solar cell were carried out by means of a 3D Maxwell equation solver, based on the finite element method (FEM). The “High Frequency Structure

• defect removal etching [53], which would dramatically improve the surface passivation. Geometrical study of nanowire arrays To further understand the interaction of light with nanowires, and how the presence of the NW array affects the absorption in the active silicon layer, optical simulations were used