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

• ][17]. The investigation of the relaxation mechanism can be therefore performed by the simulation of the experimentally obtained T(t) curves (adiabatic-like) through the theoretical T(t) dependence obtained by integration of Equation 6, under the condition that the material-dependent parameters for the

• bidimensional arrangement from those leading to the results reported in Figure 1, and therefore, rather a qualitative agreement should be expected between simulation and experiment. In this particular case, the volume fraction (as a measure of the particle density) will be computed as the volume occupied by

Alloyed Pt₃M (M = Co, Ni) nanoparticles supported on S- and N-doped carbon nanotubes for the oxygen reduction reaction

• Stéphane Louisia,
• Yohann R. J. Thomas,
• Pierre Lecante,
• Marie Heitzmann,
• M. Rosa Axet,
• Pierre-André Jacques and
• Philippe Serp

Beilstein J. Nanotechnol. 2019, 10, 1251–1269, doi:10.3762/bjnano.10.125

• coherence length is close to 2.3 nm, which gives a measurement of the average size of crystalline domains. To accurately evaluate the actual cell parameter, thus the average composition, a simulation was performed from a model derived from pure Pt (spherical NPs, 2 nm in diameter). To obtain a good

• larger after washing (2.6 nm) than before washing (2.3 nm). In that case, a correction factor of 1.5% should be applied to obtain a good agreement between the experimental results and a simulation performed from a model derived from pure Pt (spherical NP, 2 nm in diameter). From the TEM images, the mean

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

• in CPD and propose a simple model for interpreting the local surface potential at the steps with the help of surface charge redistribution, in analogy to the Smoluchowski effect, and the local dipole moment of surface atoms supported by the DFT simulation. Experimental The experiments were carried

• , which is higher than that at the step. This is consistent with the higher drop in CPD voltage across the step. For simulation details see Supporting Information File 1. Conclusion We performed CPD measurements around the steps on a TiO2(110)-(1 × 1) surface after O2 exposure using KPFM to investigate

• model for interpreting the local surface potential at the steps that combines the upward dipole moment, in analogy to the Smoluchowski effect, and the local atomic dipole moment. Blue arrows indicate the direction of the local atomic dipole moment. DFT simulation of the local electrostatic potential for

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

• electronic properties of Y(OH)3 crystals, density functional theory-based calculations were also performed using the projector augmented wave (PAW) potentials as implemented in the Vienna ab initio simulation package (VASP) [44][45][46][47]. For the exchange-correlation part of the functional, the

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 position of the tip dipole is assumed to be at the half radius of the tip [17]. Cross section simulation of MFM phase The first scan of MFM measurements provides a topographic image displaying a convolution of the tip and the nanoparticle [24]. The topographic cross section is simulated by using a

• dipole representing the nanoparticle can be calculated for each horizontal position of the tip as follows: where a is the distance between the dipoles, h is the height of the topography and z is the lift height. Figure 6 shows a simulation of both forces, capacitive (dotted purple line in Figure 6) and

• positive phase shift above the nanoparticle. However, weak attractions are expected in a ring around the nanoparticles because the magnetic signal is broader than the topographical signal (the half width of the magnetic signal is ca. 100 nm and that of the electric signal is ca. 60 nm in this simulation

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

• measurements and FDTD simulations, thus making this simulation method appropriate for characterizing evanescent field photonic sensors with a high accuracy. In order to fulfill the requirement of having a very thin biorecognition layer, we implemented a biofunctionalization protocol in which we combined a

• (FDTD) simulations have been carried out by using CST Microwave Studio simulation software. The biofunctionalization of the photonic sensors using the light-assisted immobilization process developed by our group [9][10][13], started with a cleaning of the SOI photonic chip using piranha solution (H2SO4

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• , In, La), the chlorides (XOCl and X′FCl with X = Ac, Al; X′ = Ba, Bi), and the iodides (XOI with X = Bi, La, Sc, Y). Computational Details Our present investigation of the electronic properties of the 2D halides employs density functional theory (DFT) as implemented in the Vienna ab initio simulation

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

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• experimental or theoretical simulation studies that investigated graphene, zigzag GNR or their composite material forms. Despite the remarkable advancement in recent years, this area is still in its initial development stage. Some critical issues, such as finding an ideal material and the enhancement of

• sensors are used to develop a new gas sensor model based on the carrier velocity and I–V characteristics. In addition, a first principle simulation study is employed for the band structure analysis, to calculate the charge transfer, and to evaluate the proposed models. For the sensor structure, an

• –V analysis of the AGNR-FET before and after CO and NO adsorption. It can be seen that the current has decreased after CO and NO adsorption because of the significant increase in the band gap. The I–V simulation results by ATK are compared with modelling results to demonstrate the functionality and

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

Biomimetic synthesis of Ag-coated glasswing butterfly arrays as ultra-sensitive SERS substrates for efficient trace detection of pesticides

• Guochao Shi,
• Mingli Wang,
• Yanying Zhu,
• Yuhong Wang,
• Xiaoya Yan,
• Xin Sun,
• Haijun Xu and
• Wanli Ma

Beilstein J. Nanotechnol. 2019, 10, 578–588, doi:10.3762/bjnano.10.59

• violet (CV) with a limit of detection (LOD) of 10−11 M. The 3D finite-difference time-domain (3D-FDTD) simulation results suggest that the simulated electromagnetic field enhancement of Ag-G.b.-20 is close to the experimental value. Meanwhile, the Ag-G.b.-20 nanohybrids exhibited good stability and

• time-domain simulation To better evaluate the SERS enhancement performance of the Ag-G.b.-20 substrates, an enhancement factor (EF) has been estimated based on Equation 1 [1][20]: where the ISERS and Ibulk are the integrated intensities of a same Raman peak in the SERS spectrum and bulk Raman spectrum

• close as possible to the experimental results, the simulation model of the nanostructure was extracted from FE-SEM images (Figure 4a). Figure 4b is the corresponding simulation model and a square wave with a wavelength of 532 nm was simulated to illuminate the nanostructure along the z-direction. The

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

• substrate in the vicinity of the interface can possibly lead to introduction of additional defects in the monolayer. As reported in [1][2][3][5][6][7][8][16], all these effects are generally known in the experimental literature for a specific irradiation energy, substrate and ion type, while simulation

• potentially useful since dielectric substrates are highly essential for nanoelectronic applications. Results and Discussion For each simulation a set of output values was obtained describing damage to the target substrate implemented through different processes. Among them, substrate sputtering can be on one

• atoms can receive energy optimal for the implantation as well, leading to doping of the 2D material with the substrate atoms at much greater incident ion energies (for example, 5 keV Si into graphene on SiO2 [1]; similar is naturally expected for 2D TMDs). Table 1 presents simulation results for

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

• Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam 10.3762/bjnano.10.51 Abstract We perform molecular dynamics simulation on several relevant biological

• 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

• fibril bending modulus (Yb) that depends on both YT and S. Our CG strategy can be used to extract and compare elastic properties in a systematic way. This significant advantage of CG simulations has motivated the current study, which employs MD simulation of a structure-based CG model [35][36][37][38] to

Nanocomposite–parylene C thin films with high dielectric constant and low losses for future organic electronic devices

• Marwa Mokni,
• Gianluigi Maggioni,
• Abdelkader Kahouli,
• Sara M. Carturan,
• Walter Raniero and
• Alain Sylvestre

Beilstein J. Nanotechnol. 2019, 10, 428–441, doi:10.3762/bjnano.10.42

• each monomeric unit contains one Cl atom. In the case of three-layered samples (from A to F), the SIM simulation package in the RUMP software [55] was used to simulate the experimental spectra and to determine the thickness of each layer (in monomeric units·cm−2). Figure 1 (left) shows the

Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup

• Zoltán Scherübl,
• András Pályi and
• Szabolcs Csonka

Beilstein J. Nanotechnol. 2019, 10, 363–378, doi:10.3762/bjnano.10.36

• . In this case, the line width can be reduced by decreasing the tunnel coupling to the N leads, at the price of suppressing the currents. Results of the Transport Simulation Here, we present the results we obtained from the transport model of the previous section. First, we discuss how to

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

• –machine augmented system in which the operator and the machine are connected by a real-time simulation. Here, a 3D motion control system is integrated with an ultra-high vacuum (UHV) low-temperature scanning tunnelling microscope (STM). Moreover, we coupled a real-time molecular dynamics (MD) simulation

• and combined it with a molecular dynamics (MD) simulator that simulates in real-time the manipulation process going on in the STM. The MD simulation not only provides information about the atomic scale structure of the junction, but also serves as a visual feedback to the operator in real-time who can

• adaptable trajectory is the only solution where the operator can continuously communicate with the experiment through the real-time MD simulation and define the trajectory at will using the motion control system. This human–machine augmented system thus provides a far better control of the manipulation

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

• structure were used. Simulation results consists of reflection (R) and absorption (Ai) in each layer (i) of the model, as functions of the wavelength of the incident light. A convolution of the obtained spectral data with the AM1.5 photon flux results in the implied photocurrent density (Jph,i) generated

• effect can be noted in Figure 2a, where the EQE is higher than the absorption depicted in Figure 6, and could be quantified with a rigorous electrical simulation, which is beyond the scope of this work. Nevertheless, the choice of a more transparent passivating layer could result in significant increase

• optical simulation of NW-based solar cells demonstrated that NWs amplify Fabry–Perót resonances and, at the same time, excite wave-guided modes inside the thin absorber layers. A study of the effect of the NW geometrical parameters on light absorption was carried out. For a given periodicity (Λ = 800 nm

Heating ability of magnetic nanoparticles with cubic and combined anisotropy

• Nikolai A. Usov,
• Mikhail S. Nesmeyanov,
• Elizaveta M. Gubanova and
• Natalia B. Epshtein

Beilstein J. Nanotechnol. 2019, 10, 305–314, doi:10.3762/bjnano.10.29

• . However, the ability of magnetic nanoparticle assemblies to generate heat can be improved if the nanoparticles are covered by nonmagnetic shells of appreciable thickness. Keywords: fractal clusters; magnetite nanoparticles; magneto–dipole interaction; numerical simulation; specific absorption rate

• = 50–100 Oe, at a typical frequency f = 300 kHz. This shows the substantial potential of these nanoparticles for application in magnetic nanoparticle hyperthermia. Numerical Simulation It has been recently shown [22] that the technique based on the stochastic LL equation is preferable for investigation

• random clusters with the fixed values of the initial parameters D, tsh, Np and ξmax. Simulation Results Nanoparticles with cubic anisotropy Let us first consider the SAR of a dilute assembly of fractal clusters consisting of spherical magnetite nanoparticles. In accordance with experimental data [8][11

Mechanism of silica–lysozyme composite formation unravelled by in situ fast SAXS

• Tomasz M. Stawski,
• Daniela B. van den Heuvel,
• Rogier Besselink,
• Dominique J. Tobler and
• Liane G. Benning

Beilstein J. Nanotechnol. 2019, 10, 182–197, doi:10.3762/bjnano.10.17

• each other without any LZM molecules in between, or that the protein molecules, if present within the aggregates and among individual silica NPs, are very strongly deformed, likely to a point that they barely contribute to the determined RHS. Nevertheless, the simulation in Figure 2A clearly shows that

• ) the position of the simulated peak visibly shifts towards higher q values with respect to the measured peak. Here, aReHS is associated with the presence of a single LZM molecule located in between individual silica NPs with the diameter of the LZM molecule represented by 2aReHS. The simulation in

Sputtering of silicon nanopowders by an argon cluster ion beam

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Zhenguo Wang,
• Wenbin Zuo,
• Sergey Belykh,
• Alexander Tolstogouzov,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2019, 10, 135–143, doi:10.3762/bjnano.10.13

• nanowires. There are many molecular dynamics simulations using the collision cascade theory and, at the same time, only a few experimental studies on the interaction of monomer and cluster projectiles with nanodimensional systems. Using a MD simulation, Kissel et al. [16] have studied the effect of the

Surface plasmon resonance enhancement of photoluminescence intensity and bioimaging application of gold nanorod@CdSe/ZnS quantum dots

• Siyi Hu,
• Yu Ren,
• Yue Wang,
• Jinhua Li,
• Junle Qu,
• Liwei Liu,
• Hanbin Ma and
• Yuguo Tang

Beilstein J. Nanotechnol. 2019, 10, 22–31, doi:10.3762/bjnano.10.3

• the LSPR of the GNRs in a way that the QD PL is enhanced when the GNR LSPR interacts with the QD PL plane wave. As shown in Figure 2a, from the FDTD simulation results we can see that (1) the highest PL enhancement, at 630 nm, occurred when d (d is the dipole-source center to GNR-center length) was

• clearly determine that the dipole source is the actual source of the PL enhancement, we use light polarization directed along the long and short axes of the GNRs to stimulate the longitudinal and transverse modes, respectively. As shown in Figure 2b, which shows the FDTD simulation results, we can see

• plasmon resonance of GNRs. The experimental results correlated well with the theoretical simulation. The results of the biological detection study indicated that this nanomaterial is biocompatible and that there is significant PL signal for cell imaging. This research is promising for future nanophotonics

Electrostatic force microscopy for the accurate characterization of interphases in nanocomposites

• Diana El Khoury,
• Richard Arinero,
• Jean-Charles Laurentie,
• Mikhaël Bechelany,
• Michel Ramonda and
• Jérôme Castellon

Beilstein J. Nanotechnol. 2018, 9, 2999–3012, doi:10.3762/bjnano.9.279

• deduced by comparison of experimental data and numerical simulations, as well as the interface state of silicone dioxide layers. Keywords: atomic force microscopy; building-block materials; dielectric permittivity; electrostatic force microscopy; finite element simulation; interphases; nanocomposites

• was measured during the experiments. This AC-2ω signal is equal to the half of the DC signal (please refer to the theoretical equations of the DC versus AC-2ω components in [58][65]). Hence, the DC simulation results were divided by a factor of 2 to obtain the corresponding AC-2ω simulation values and

• profiles, b) average EFM signal profiles (lower panel) and the corresponding EFM images (upper panels). Typical simulation of the electric field map obtained with a 2D axisymmetric model of the EFM tip and the PS + Al2O3 sample as a substrate. Experimental data and simulations for a typical reference

Size limits of magnetic-domain engineering in continuous in-plane exchange-bias prototype films

• Alexander Gaul,
• Daniel Emmrich,
• Timo Ueltzhöffer,
• Henning Huckfeldt,
• Hatice Doğanay,
• Johanna Hackl,
• Muhammad Imtiaz Khan,
• Daniel M. Gottlob,
• Gregor Hartmann,
• André Beyer,
• Dennis Holzinger,
• Slavomír Nemšák,
• Claus M. Schneider,
• Armin Gölzhäuser,
• Günter Reiss and
• Arno Ehresmann

Beilstein J. Nanotechnol. 2018, 9, 2968–2979, doi:10.3762/bjnano.9.276

• the MFM data and the different DW types appear blurred. In the simulations, such structures are clearly visible and blurring of DWs appears at d = 1 μm. Again, the reason for the discrepancy between measurement and simulation can be attributed to local fluctuations of material parameters resulting

Site-controlled formation of single Si nanocrystals in a buried SiO₂ matrix using ion beam mixing

• Xiaomo Xu,
• Thomas Prüfer,
• Daniel Wolf,
• Hans-Jürgen Engelmann,
• Lothar Bischoff,
• René Hübner,
• Karl-Heinz Heinig,
• Wolfhard Möller,
• Stefan Facsko,
• Johannes von Borany and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2018, 9, 2883–2892, doi:10.3762/bjnano.9.267

• density of NCs and even NCs that are connected to the interface are observed in the simulation (see Figure 2b). In general, by carefully comparing Figure 1 with the simulated Si NC bands, presented in Figure 2, one can see that neither the cluster size nor the density matches perfectly. To obtain a

• comparable density and NC size, the fluence in the simulation needs to be significantly lower for all investigated cases. This systematic deviation and the underlying physics is subject of an ongoing investigation. In order to optimize the self-assembly of vertically self-aligned Si NCs with a narrow size

• recoil atom generated at x, and dσ/dl the differential cross section for the generation of such a recoil. To calculate the 1D mixing efficiency by means of static BCA computer simulation, the number of displacements Nd in a depth interval Δx at x with a displacement between l and l + Δl is counted for a

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

• the resist through sputtering and loss of substrate crystallinity. The situation for Ga+ ions is further complicated by the property of Ga+ as a p-type dopant of silicon. Scattering and range can be calculated using Monte Carlo simulation codes with typical results as shown in Figure 3 [30]. The

• simulation, using a 4 nm diameter electron probe, ring-shaped deposits smaller than the electron beam diameter were shown to be possible. However, quantitative models to predict the maximum resolution attainable as a function of experimental parameters would be essential for making EBIE a viable

• piezo-resistors configured in an integrated Wheatstone bridge to reduce the influence of noise and temperature [150][151]. A simulation model was developed to optimize the size, length and placement of the heater and the deflection sensor [148][152]. Other actuation and sensing principles can be used as