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

• Raman active mode in 1L, ML and bulk WSe2 which is shown in Figure 4e. It was found that at high T there was a convergence of , indicating that the phonon–phonon scattering was dominant in all the specimens which governed the decay mechanism at high T. In contrast, at low T, τ (Figure 4a and 4b) and

Understanding nanoparticle flow with a new in vitro experimental and computational approach using hydrogel channels

• Armel Boutchuen,
• Dell Zimmerman,
• Abdollah Arabshahi,
• John Melnyczuk and
• Soubantika Palchoudhury

Beilstein J. Nanotechnol. 2020, 11, 296–309, doi:10.3762/bjnano.11.22

• geometry is an unbent circular tube, the structured mesh is found suitable for the better convergence of simulations. A grid refinement study was made with several different structured meshes in each coordinate direction. The effect of altering the cell size was investigated with grids of 65, 129 and 193

A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• scalar gain γ instead of updating covariance matrix and Kalman gain equations. This gives the Lyapunov filter a computational complexity of as additional frequencies are modeled, a significant improvement over the Kalman filter. A key property of the Lyapunov filter is exponential convergence of the

• estimated states [56], with the tunable loop gain γ governing the speed of convergence. The multifrequency Lyapunov filter is implemented as parallel linear observers tuned to a particular frequency ωi, as depicted in Figure 6. An error signal is generated by feeding back an estimate of the input signal as

• this form, represents the estimated input signal and the amplitude Ai and phase ϕi estimates are found by applying Equation 4 to each quadrature and in-phase pair of . A key property to ensure exponential convergence of to x is to guarantee that C is persistently excited [56]. Convergence is shown

Nonlinear absorption and scattering of a single plasmonic nanostructure characterized by x-scan technique

• Tushar C. Jagadale,
• Dhanya S. Murali and
• Shi-Wei Chu

Beilstein J. Nanotechnol. 2019, 10, 2182–2191, doi:10.3762/bjnano.10.211

• /convergence, which is determined by the real part of the nonlinear refractive index in the thin sample. When there is no nonlinearity, the transmittance is again constant no matter where the thin sample is. When nonlinear refractive index exists, the sample acts like a z-dependent lens that modifies the

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• [21][22] to obtain a more accurate band structure. The vacuum distance is set to 15 Å to avoid interactions between the MoO3 monolayer and its periodic images. A plane-wave basis set with a cutoff of 520 eV is chosen, and the k-mesh is tested to be 10 × 10 × 1 for the purpose of convergence. Based on

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

• cluster DFT calculations, as described previously [44]. ESP values for the symmetry unique atoms of MFU-4 and SF6 are displayed in the Supporting Information File 1 in Figure S13. Prior to the potential energy scan, all atomic positions of the MFU-4 unit cell were fully relaxed at tight convergence

Giant magnetoresistance ratio in a current-perpendicular-to-plane spin valve based on an inverse Heusler alloy Ti₂NiAl

• Yu Feng,
• Zhou Cui,
• Bo Wu,
• Jianwei Li,
• Hongkuan Yuan and
• Hong Chen

Beilstein J. Nanotechnol. 2019, 10, 1658–1665, doi:10.3762/bjnano.10.161

• ) generalized gradient approximation (GGA). A Monkhorst–Pack grid of 13 × 13 × 1 for k-point sampling, a self-consistent field (SCF) convergence criterion of 1 × 10−5 eV, and a plane-wave basis cutoff energy of 550 eV were applied. The Keldysh nonequilibrium Green’s function (NEGF) theory, as implemented in

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

• magnetic states in ferromagnetic materials [3]. The non-diffracting behavior of Bessel beams could be used as an electron probe with enhanced depth of focus [4] as for conventional (sub-angstrom) electron probes the depth of focus is reduced to a few nanometers due to the large convergence angles used in

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• relaxations, the total energy difference between the sequential steps in the calculations was taken to be 10−5 eV as the convergence criterion. On each unit cell, the total forces were reduced to a value less than 10−4 eV/Å. Г-centered k-point meshes of 2 × 2 × 2 were used for a 128-atom supercell of bulk Y

Synthesis and characterization of quaternary La(Sr)S–TaS₂ misfit-layered nanotubes

• Marco Serra,
• Erumpukuthickal Ashokkumar Anumol,
• Dalit Stolovas,
• Iddo Pinkas,
• Ernesto Joselevich,
• Reshef Tenne,
• Andrey Enyashin and
• Francis Leonard Deepak

Beilstein J. Nanotechnol. 2019, 10, 1112–1124, doi:10.3762/bjnano.10.111

• Ry. All calculations were performed using variable-cell and atomic position relaxations, with convergence criteria corresponding to the maximum residual stress of 0.1 GPa for each component of the stress tensor, and the maximum residual force component of 0.05 eV/Å. Preliminary test calculations of

Electronic and magnetic properties of doped black phosphorene with concentration dependence

• Ke Wang,
• Hai Wang,
• Min Zhang,
• Yan Liu and
• Wei Zhao

Beilstein J. Nanotechnol. 2019, 10, 993–1001, doi:10.3762/bjnano.10.100

• suppress the interaction between adjacent layers, a 15 Å vacuum distance was imposed along the z-axis. Each doped structure was optimized self-consistently with a cut-off energy of 500 eV until the convergence criterions were satisfied. In terms of our convergence criterions, the tolerance of energy and

Topochemical engineering of composite hybrid fibers using layered double hydroxides and abietic acid

• Liji Sobhana,
• Lokesh Kesavan,
• Jan Gustafsson and
• Pedro Fardim

Beilstein J. Nanotechnol. 2019, 10, 589–605, doi:10.3762/bjnano.10.60

• brucite layers were already utilized to graft cellulose through cellulosic O–H polarization. Thus, LDH act as a perfect structure-directing agent in C-HF materials. The XRD spectra of C-HF show a convergence of diffraction peaks of cellulose and AA at 14–16°, a shift from 14.77° to 15.20° and enhanced

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO₂ conversion

• Qianyi Cui,
• Gangqiang Qin,
• Weihua Wang,
• Lixiang Sun,
• Aijun Du and
• Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

• unit cell of 12.58 × 12.58 × 15.00 Å3 with convergence criterion of 1 × 10−6 a.u. for the energy and 0.005 Å for the displacements. For the 5 × 5 supercell, the k-point sampling of the Brillouin zone (BZ) adopted a 5 × 5 × 1 Monkhorst–Pack grid [61]. The Mulliken charge analysis was employed to

Accurate control of the covalent functionalization of single-walled carbon nanotubes for the electro-enzymatically controlled oxidation of biomolecules

• Naoual Allali,
• Veronika Urbanova,
• Mathieu Etienne,
• Xavier Devaux,
• Martine Mallet,
• Brigitte Vigolo,
• Jean-Joseph Adjizian,
• Chris P. Ewels,
• Sven Oberg,
• Alexander V. Soldatov,
• Edward McRae,
• Yves Fort,
• Manuel Dossot and
• Victor Mamane

Beilstein J. Nanotechnol. 2018, 9, 2750–2762, doi:10.3762/bjnano.9.257

• and 11 mrad for an image resolution of 1024 × 1024 pixels with a dwell-time of 60 µs. STEM-EDS and STEM-EELS experiments were performed with an electron probe of about 0.17 nm and a convergence semi-angle of 24 mrad. The energy resolution was about 0.45 eV. The collection angle of the EELS

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• , Dassault Systèmes, France) and employing C3D8I elements, which are 8-node bricks with 8 points of integration and incompatible modes. The choice of this element type allows a good representation of the stress singularities at the edges (see Supporting Information File 5). A convergence study is carried out

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• obtained previously [20]. However, we also show that the method can suffer in terms of accuracy for large (5 μm) textures for what is considered reasonable simulation time (about one day for the complete wavelength range of interest on a typical desktop PC). Additionally, RCWA may have convergence

• convergence towards a steady solution, 30 sublayers are sufficient for both angles of incidence, at least for wavelengths above 450 nm. The errors in JSC as a function of the number of sublayers (Figure 5e) indicate a lower |ΔJSC| for the case of normal incident light. 300 sublayers were used as the reference

• -vertical light incidence. The convergence of non-vertical incidence is again a bit worse than for the vertical incidence, although the differences are small from 500 nm onwards. The errors in JSC as a function of the number of sublayers show that the |JSC| error corresponding to case of normal incident

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• bonds of Si to O and N. The root mean square (RMS) and peak force convergence limits for all atoms were 3 × 10−4 Ha/a0 (Hartrees per Bohr radius) or 80 meV/nm and 4.5 × 10−4 Ha/a0 or 120 meV/nm, respectively. Tight convergence criteria were applied to the self-consistent field routine. Ultrafine

• Supporting Information File 1) due to the inter-NC distance of merely 1 nm, accounting for some ICT convergence from Si NCs to SiO2 or Si3N4. From Figure 2c we see that an ICT saturation is evident for ≥2 ML SiO2. This saturation is less apparent when Si3N4 is applied as the embedding matrix. We explain this

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

• red dashed line. The graphs depicting the results from simulations at 600 kHz and 3 MHz were zoomed-in so that the convergence process can be noticed. Simulated surface photovoltage spectroscopy curves of the F5BnPA region for different SPV built-up and decay input parameters. Experimental data was

Atomic-level characterization and cilostazol affinity of poly(lactic acid) nanoparticles conjugated with differentially charged hydrophilic molecules

• María Francisca Matus,
• Martín Ludueña,
• Cristian Vilos,
• Iván Palomo and
• Marcelo M. Mariscal

Beilstein J. Nanotechnol. 2018, 9, 1328–1338, doi:10.3762/bjnano.9.126

• calculations [38][39]. In this work, a modified version of the force field developed by Kim and van Duin, optimized for C/O/H/N/P systems [40], was used. The convergence criteria for energy minimization, rupture temperature limit and the optimal separation distance for PLA chains to build the PLA core were

• configuration was minimized using the Polak–Ribiere version of the conjugate gradient (CG) algorithm [41] with a convergence criteria of 1.0e−12 followed by an equilibration of 2 ns at 310 K using NVT ensemble (constant temperature and volume) and a timestep of 1 fs. A Nose–Hoover thermostat was used to control

Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert,
• Michael R. P. Ragazzon and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2018, 9, 490–498, doi:10.3762/bjnano.9.47

• particular frequency is recovered by Filter description The Lyapunov filter [28] is implemented as a linear observer as shown in Figure 2. A key property of the filter is exponential convergence of the estimated states [29], with the tunable loop gain constant γ governing the speed of convergence. The filter

• -phase pair of . A key requirement to ensure exponential convergence of to x, is to guarantee that c is persistently excited [29]. Convergence is shown for the single-frequency filter in [28], and can easily be extended for the multifrequency case. Furthermore, exponential convergence of means that

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• to 1 eV (as in [11]). The convergence condition of the self-consistent electronic loops was set to 10−6 eV, while the atomic positions were relaxed until the forces reached a value lower than 0.01 eV/Å. The atoms of the two bottom layers of the metal slab were kept fixed at their bulk positions and

Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips

• Sumit Tewari,
• Koen M. Bastiaans,
• Milan P. Allan and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2017, 8, 2389–2395, doi:10.3762/bjnano.8.238

• analysis of the results of this procedure we define a parameter that could capture the convergence of the tip structure to this symmetric state. This same parameter should also serve to verify whether tips such as those in Figure 3 and Figure 4 converged to the same state. For comparing the constant-height

• normalized to the maximum current level which for the above figures are 38 and 24 nA, respectively Ratio of major to minor axis of the elliptical fit showing the convergence of the tip apex structure to a circularly symmetric shape. Three independent runs are shown by blue, green and red symbols. The two

Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication

• Kangmei Li,
• Dalei Jing,
• Jun Hu,
• Xiaohong Ding and
• Zhenqiang Yao

Beilstein J. Nanotechnol. 2017, 8, 2324–2338, doi:10.3762/bjnano.8.232

• accuracy of calculation and the rate of convergence, the meshing operation follows several criteria: (1) the use of structured grids, as far as possible; (2) the ratio of the length of the longest element edge to the length of the shortest element edge should be controlled below 5:1; (3) the skewness

Modelling focused electron beam induced deposition beyond Langmuir adsorption

• Dédalo Sanz-Hernández and
• Amalio Fernández-Pacheco

Beilstein J. Nanotechnol. 2017, 8, 2151–2161, doi:10.3762/bjnano.8.214

• saturated monolayers, appearance of multilayers, or the convergence from the multilayer model to the Langmuir model, can be understood in terms of the characteristic time scales of the system. These results are synthesized in a set of dimensionless FEBID frequency maps for Langmuir, and homogeneous and

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• a probe-corrected FEI Titan 60-300 equipped with a high brightness field emission gun (X-FEG), a CEOS corrector for the condenser system and a Gatan Tridiem 866 ERS image filter/spectrometer. The EELS acquisition was performed with a convergence angle of 25 mrad, a collection semi-angle of around 60