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

• -hexagonal layer with lattice parameter a2BL CoO = 3.0–3.1 Å [18]. STM images of both films show the positions of the oxygen atoms as bright protrusions [20]. Computational Methods Non-magnetic ab initio calculations were performed using the Vienna Ab-initio Simulation Package (VASP) [32] employing the PBE

• was kept fixed laterally at a position guided by the analysis of our experimental STM images of 1 and by our results on Co phthalocyanine [35]. For the 1BL system, only the bottom Ir layer was kept fixed. For the 2BL calculations, the bare substrate was relaxed first, keeping the bottom Ir layer fixed

• . 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

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

• ) calculations for the isolated molecule indicate that the torsional angle changes from 35 to only 20° upon the formation of the anion. Presumably, the electrostatic interaction of the charged molecules with the substrate completes the planarization. In summary these results suggest that MgO films prepared under

• overlap between the phenyl rings. This will cause an increase in the energy spread of the π bands, resulting in a decrease in the ionization potential and an increase in the electron affinity. Gas phase DFT calculations show that the EA of planar 6P (1.74 eV) is indeed 0.3 eV higher than the EA of twisted

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

• characterizing a family of pyridin-4-ylethynyl-functionalized pyrene derivatives in different environments. UV–vis measurements in toluene solutions revealed absorption at wavelengths consistent with density functional theory (DFT) calculations, while emission experiments showed a high fluorescence quantum yield

• effect of the substitution on the electronic properties of the pyrene core, DFT calculations were performed (B3LYP/6-31G** level of theory, in vacuum). The frontier Kohn-Sham orbitals of pyrene and the di- and tetrasubstituted (pyridin-4-ylethynyl)pyrenes 1, 2, and 3 are shown in Figure 1b (see also

• similarities. For example, the number of antinodes as well as the nodal planes between the experimental images and the calculations were in agreement, strongly suggesting that the STM contrast indeed reflected the MO contributions, corroborating the assignment of spectral features to the HOMOs and the LUMOs

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

• acid (FDCA) molecules on bulk and thin film CaF2(111) surfaces with non-contact atomic force microscopy (NC-AFM). We use NC-AFM image calculations with the probe particle model to interpret this distinct shape by repulsive interactions between the NC-AFM tip and the top hydrogen atoms of the

• ionised derivates calculations yielded rotational barrier values of up to 1.4 eV [19]. From this class of molecules we investigate the ferrocene derivate 1,1’-ferrocene dicarboxylic acid (FDCA), a ferrocene functionalised with two carboxylic acid moieties. This molecule has been analysed before on Ag(111

• ), Cu(110), and Cu3N/Cu(110) surfaces [20] as well as on the insulator surfaces calcite(104) [21] and CaF2(111) [22]. An eclipsed ferrocene conformation was found to be predominant on the metallic surfaces [20] and on calcite(104) [21]. On CaF2(111) surfaces, density functional theory (DFT) calculations

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• by weighing the amount of precursor before and after each synthesis using a high precision scale. The calculations were performed by using where is the precursor gas flow rate, Δm is the mass of evaporated precursor, V is the molar volume of an ideal gas (22.4 mol/L), t is overall process time

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

• concentrations was considered as 100% in further calculations. Analysis of the size of γ-Fe2O3 nanoparticles in different media by laser correlation spectroscopy The size of γ-Fe2O3 nanoparticles was measured by dynamic light scattering using a laser correlation spectrometer ZetaSizer-3 (Malvern Instrument, UK

• concentrations in the corresponding incubation medium with no nanoparticles added was used in calculations as a control (100%) and consisted of 30,000 cpm/mL at 1.86 µM glutamate/ʟ-[14C]glutamate. The results were expressed as percentage of the total amount of ʟ-[14C]glutamate in the control. Efficacy of

• literature data have indicated that the nanoparticle concentration is a crucial parameter for the absorption efficacy [26][27]. The ʟ-[14C]glutamate count at the corresponding concentrations in each tetrad was considered as 100% in further calculations (Figure 2). It was shown that nanoparticles at a

Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

• the vW model fails since gold droplets are formed on the silicon oxide surface. A deep insight into the characteristics and properties of the observed material is needed to perform calculations using van der Waals interactions. However, thermal silicon oxide has no defined crystallographic orientation

• calculations. Hamaker constants correspond to the susceptibility of particles to an electric field of very small length scales generated by the particles themselves [28]. For this reason, these constants are used to determine energy and force values in van der Waals interactions. A more detailed description of

• these clusters or if it just becomes thinner or perforated. However, the TEM data do not show any evidence of a wetting layer at room temperature, since at this temperature only very small gold clusters are seen. This is in agreement with low-energy electron microscopy (LEEM) calculations, which predict

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

• -terminated tips In Figure 3, we compare AFM line profiles taken across the defect of interest (blue) and a corresponding defect-free region (grey) with a simple theoretical structure optimized by molecular dynamics calculations (see Methods for parameters). A preliminary comparison of Figure 3 with the

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

• We present both theoretical and experimental investigations of the proximity effect in a stack-like superconductor/ferromagnetic (S/F) superlattice, where ferromagnetic layers with different thicknesses and coercive fields are made of Co. Calculations based on the Usadel equations allow us to find

• from both sides, leading to two independent parameters, γBSF and γBFS. The ratio between these parameters, γ = ρSξS/ρFξF, is a suitable parameter to understand the physics of the system, since it depends only on the material properties. In our calculations we put the origin of the x axis at the free

• Stuttgart. The lithography was made in the Stockholm University. Funding We acknowledge the partial financial support from Grant No. 20-69-47013 of the Russian Science Foundation (theoretical approach and calculations). R. Morari is grateful for the support from the Russian Ministry of Education and Science

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• SnO2 doped with non-metal elements (F, S, C, B, and N) were studied using first-principles calculations. The theoretical results show that doping of non-metal elements cannot change the structure of SnO2 but result in a slight expansion of the lattice volume. The most obvious finding from the analysis

• reflectivity in the infrared region, and the reflectance of the crystals doped with N, C, S, and B decreased sequentially. Based on this theoretical calculations, F-doped SnO2 is found to be the best photoelectric material for preparing low-emissivity coatings. Keywords: density functional theory (DFT); doped

• . When the concentration of the precursor solution was adjusted to 0.15 M and the substrate temperature was 773 K, a film with a resistivity of 1.2 × 10−4 Ω·cm was obtained [10]. Theoretical calculations, based on first principles, show that the doping of N into the SnO2 crystal structure can introduce

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

• Kamila A. Szewczyk,
• Izabela A. Domagalska,
• Artur P. Durajski and
• Radosław Szczęśniak

Beilstein J. Nanotechnol. 2020, 11, 1178–1189, doi:10.3762/bjnano.11.102

• in Li-hBN is characterized by much lower values of the critical temperature (TLOVCC ∈ {19.1, 15.5, 11.8} K, for μ* ∈ {0.1, 0.14, 0.2}, respectively) than would result from calculations not taking this effect into account (TMEC∈ {31.9, 26.9, 21} K). From the technological point of view, the low value

• of TC limits the possible applications of Li-hBN. The calculations were carried out under the classic Migdal–Eliashberg formalism (ME) and the Eliashberg theory with lowest-order vertex corrections (LOVC). We show that the vertex corrections of higher order (λ3) lower the value of TLOVCC by a few

• ] and quantum information technology [44][45]. Currently, the most promising research seems to be the properties of the superconducting state in Li-intercalated hexagonal boron nitride bilayer (Li-hBN) compounds. Based on DFT calculations, it has been shown that the critical temperature (TC) of the

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• calculations [42] were performed for the HOMO alone. However, both vibronic excitations mainly involve tetracene stretching vibrations and both the HOMO and the LUMO are close to the tetracene backbone [43][44]. Therefore, vibronic progression induced by one of these vibrational modes is likely to occur in the

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• chemical signal. In addition, it has been shown that the 2JPP coupling constant values decrease when the electron-withdrawing power of the substituents decreases [55]. The density functional theory (DFT) calculations on free and Au-complexed P=N–P=S linkages have shown that a charge is transferred from the

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• unoccupied molecular orbital (LUMO) of tetracyanoquinodimethane (TCNQ) molecules is significantly narrower than on the bare substrate and that it is accompanied by a characteristic satellite structure. Employing simple calculations within the Franck–Condon model, we reveal their vibronic origin and identify

• been found in calculations. It has been interpreted as a hybrid metal–MoS2 or an interface state [38]. The conduction band minimum, which is expected to lie at the point for quasi free-standing as well as metal-supported single-layer MoS2 [29][42][43][44], is hardly visible in the tunneling spectra

• , we corroborate this assignment by simulating constant-height dI/dV maps of a free, flat-lying molecule. We first calculated the gas-phase electronic structure using density functional theory (DFT) calculations with the B3PW91 functional and the 6-31g(d,p) basis set as implemented in the Gaussian 09

Excitonic and electronic transitions in Me–Sb₂Se₃ structures

• Nicolae N. Syrbu,
• Victor V. Zalamai,
• Ivan G. Stamov and
• Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

• . Several studies have shown that the bandgap is established due to allowed transitions that happen within 1.0 and 1.9 eV [6][8][10], whereas other studies show that the bandgap is determined by forbidden transitions [21][22][23]. In addition, the energy band structure and the theoretical calculations in

• the reflection spectra for both Е||с and Е⟂с polarization cases at 300 K. The calculations showed that for the polarization Е||с the background dielectric constant (εb) is equal to 7.5, the energy of the transversal exciton (ωТ) is 1.192 eV, the longitudinal-transversal splitting (ωLT) is 15 meV, the

• damping factor (γ) is 110 and the translational mass of the exciton (M) is 3.5m0 (Table 2). For the excitonic series С the following parameters were calculated: ωТ = 1.310 eV, ωLT = 17 meV, γ = 150 and M = 3.9m0. For the E⟂c polarization case the calculations of the reflection spectra profiles gave the

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• Abstract Recent experiments suggest graphene-based materials as candidates in future electronic and optoelectronic devices. In this paper, we propose to investigate new photodetectors based on graphene nanomeshes (GNMs). Density functional theory (DFT) calculations are performed to gain insight into

• makes it suitable for optical devices. Keywords: absorption spectra; DFT calculations; graphene nanomesh; graphene nanoribbon; photodetectors; Introduction Graphene monolayers with honeycomb crystal structure have unique electrical and optical properties and have received a lot of attention recently

• ]. In this paper, for the first time, we study a new GNM-based photodetector using computational modeling. In order to do a complete device simulation, we initially perform ab initio DFT calculations to investigate the electronic and optical properties of the several materials used in devices channels

Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

• Santoshi Misra and
• Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

• prime (´) denotes differentiation with respect to η, and the physical parameters involved in the equations are defined as follows: The abbreviations used for the calculations are summarized in Table 1. Solving a system of first-order differential equations The nonlinear and coupled partial differential

Three-dimensional solvation structure of ethanol on carbonate minerals

• Hagen Söngen,
• Ygor Morais Jaques,
• Peter Spijker,
• Christoph Marutschke,
• Stefanie Klassen,
• Ilka Hermes,
• Ralf Bechstein,
• Lidija Zivanovic,
• John Tracey,
• Adam S. Foster and
• Angelika Kühnle

Beilstein J. Nanotechnol. 2020, 11, 891–898, doi:10.3762/bjnano.11.74

• isolated ethanol molecule on calcite obtained with DFT calculations [13]. Consequently, the hydrocarbon chains of the ethanol molecules point away from the surface. This results in one ethanol molecule per CaCO3 at the calcite (10.4) surface. The ordered first layer of ethanol molecules above the calcite

• distance is in good agreement with the above-cited previous calculations of ethanol interfaces. Moreover, observing no order in the upper layers fits well to the MD simulations from previous theoretical studies, which do not indicate significant lateral order in the layers above the first layer for the

Simulations of the 2D self-assembly of tripod-shaped building blocks

• Łukasz Baran,
• Wojciech Rżysko and
• Edyta Słyk

Beilstein J. Nanotechnol. 2020, 11, 884–890, doi:10.3762/bjnano.11.73

• structures, which are not reproducible with off-lattice simulations. Acknowledgements Calculations were carried out at the Academic Computer Centre in Gdansk. a–d) Schematic representation of the models used in this work. Silver and red circles correspond to the components of the backbone and “phantom

A Josephson junction based on a highly disordered superconductor/low-resistivity normal metal bilayer

• Pavel M. Marychev and
• Denis Yu. Vodolazov

Beilstein J. Nanotechnol. 2020, 11, 858–865, doi:10.3762/bjnano.11.71

• of a single S layer at zero temperature). Our calculations show, that the proper choice of the thickness of the N layer leads both to nonhysteretic current–voltage characteristics even at low temperatures and a relatively large product IcRn. Keywords: normal metal–superconductor bilayer; Josephson

• found from the self-consistings solution of Equation 1–Equation 3 and Equation 5. In numerical calculations we use dimensionless units. The magnitude of the order parameter is normalized by kBTc0 = Δ(0)/1.76, lengths are in units of ≈ 1.33ξ(0), where is the superconducting coherence length at T = 0

• , and the current is in units of the depairing current Idep of the superconductor at T = 0. To calculate the CPR we numerically solve Equation 1–Equation 3 and Equation 5 by using an iteration procedure with fixed δϕ. When self-consistency is achieved (we stop the calculations when the maximal relative

Agglomerates of nanoparticles

• Dieter Vollath

Beilstein J. Nanotechnol. 2020, 11, 854–857, doi:10.3762/bjnano.11.70

• approximation. Taking into account the boundary conditions, the parameters for the Weibull distribution function were determined by an iteration process using nested intervals. The calculations were performed for 102, 103, and 104 particles. Depending on the starting values, the resulting distribution function

• kinds of the probability distribution differ in the sign of the enthalpy of interaction. Table 1 displays the detailed results of the calculation for different sizes of the ensemble of particles. The calculations were performed for three different numbers of particles in the ensemble. The exact number

• maximum of the distribution function is either at the state of non-agglomerated particles or at the entropy and size of the largest particle agglomerates. The calculations show that, depending on the number of particles within the ensemble, the size of the largest agglomerate within an ensemble follows a

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• [6], CuPc [7][8][9][10], ZnPc [11], FePc [12] and H2Pc [13]), while their nonplanar counterparts such as SnPc have been rarely probed [14]. Spectroscopy studies or density functional theory (DFT) calculations of molecular species adsorbed onto titanium dioxide can be an arduous task, especially for

• Kα) combined with a Scienta EAC2200 Nanosam 570 analyzer. Ti 2p peaks were used for global calibration of the XPS spectra. A Shirley function was used for background correction during XPS data analysis. Calculations were performed by employing density-functional theory (DFT) using the SIESTA code [15

• assume that the shape asymmetry of SnPc may also appear as a result of the presence of the surrounding molecules, or it can arise from the corrugated nature of the rutile (110) surface including its defects. To confirm the identification of Sn-up and Sn-down geometries, we performed DFT calculations. A

A set of empirical equations describing the observed colours of metal–anodic aluminium oxide–Al nanostructures

• Cristina V. Manzano,
• Jakob J. Schwiedrzik,
• Gerhard Bürki,
• Laszlo Pethö,
• Johann Michler and
• Laetitia Philippe

Beilstein J. Nanotechnol. 2020, 11, 798–806, doi:10.3762/bjnano.11.64

• colour model including luminance (Y) and chromaticity (xy) using the CIE 1931 colour space [12], were obtained from the UV–vis reflectance measurements of the nanostructures according to the detailed description in [23]. For these calculations, only the wavelength range of 400–700 nm was considered. (a

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• . The Raman band for Si at 520.7 cm−1 was used as a reference to calibrate the spectrometer. The laser spot size and spatial resolution were calculated to be ≈2.6 µm and 1.3 µm respectively and the supporting calculations are outlined in Section 1 of the Supporting Information File 1. The WSe2

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• calculations based on N2 at 77 K on carbon with slit pores. Thermogravimetric analysis (TGA) was done with a Netzsch TG 209 F3 Tarsus device equipped with an Al crucible applying a heating rate of 10 K/min under inert atmosphere. Elemental analyses (CHN) were performed with a Perkin Elmer 2400 apparatus. Flame