Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• photocarrier lifetime is quantified by performing KPFM measurements under frequency-modulated illumination. Our multimodal approach provides a unique way to investigate the interplay between the charges and ionic species, the photocarrier-lattice coupling and the photocarrier dynamics in hybrid perovskites

• performing KPFM measurements under frequency-modulated illumination. These results establish that nc-AFM/KPFM can be effectively used to investigate both the photocarrier dynamics and the photon–lattice coupling in organic–inorganic hybrid perovskites. Methods Sample preparation Methylammonium lead

• the dependency of the average potential with respect to the modulation frequency, it is possible to extract time constants characterizing the photopotential decay dynamics between the light pulses. More information about KPFM operations under frequency-modulated illumination (FMI-KPFM) can be found in

Josephson effect in junctions of conventional and topological superconductors

• Alex Zazunov,
• Albert Iks,
• Miguel Alvarado,
• Alfredo Levy Yeyati and
• Reinhold Egger

Beilstein J. Nanotechnol. 2018, 9, 1659–1676, doi:10.3762/bjnano.9.158

• that Λ is real-valued and does not depend on . Due to the constraint (Equation 8) on the dot occupation, the last two terms in Equation 10 do not contribute to the system dynamics and we obtain A formally exact expression for the partition function is then given by where with in Equation 9 and the

• dimensionless parameter From Equation 6 and Equation 7, the bGF matrix elements needed in Equation 19 follow as Now |g12(τ)| is exponentially small unless Δ|τ| < 1. In particular, g12(τ) → −δ(τ) for Δ → ∞. Moreover, for B Δ with B ≡ |B|, the magnetic impurity (S) dynamics will be slow on time scales of the

• represents the largest energy scale of interest and hence the dynamics is confined to the subgap region. In this case, we can approximate . After the rescaling in Equation 43, we arrive at an effective action, Seff → Sat, valid in the atomic limit, where is the reflection amplitude of the SAC, see Equation

Free-radical gases on two-dimensional transition-metal disulfides (XS₂, X = Mo/W): robust half-metallicity for efficient nitrogen oxide sensors

• Chunmei Zhang,
• Yalong Jiao,
• Fengxian Ma,
• Sri Kasi Matta,
• Steven Bottle and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1641–1646, doi:10.3762/bjnano.9.156

• meV and 3 Å, suggesting that water is physically adsorbed on the surface of the WS2 nanosheet. Monolayer MoS2 [38] and multilayer MoS2 field effect transistors [17] for sensing NO at room temperature have been fabricated experimentally. In this work, the ab initio molecular dynamics simulations at

Nanoscale electrochemical response of lithium-ion cathodes: a combined study using C-AFM and SIMS

• Jonathan Op de Beeck,
• Nouha Labyedh,
• Alfonso Sepúlveda,
• Valentina Spampinato,
• Alexis Franquet,
• Thierry Conard,
• Philippe M. Vereecken,
• Wilfried Vandervorst and
• Umberto Celano

Beilstein J. Nanotechnol. 2018, 9, 1623–1628, doi:10.3762/bjnano.9.154

• ionic dynamics such as the observation of motion of ions in mixed ionic–electronic conductors using the electrical current sensed by the AFM tip [6]. However, these techniques all probe the electrical, structural or ionic properties of the film and do not provide any direct information on the local

Nanocomposites comprised of homogeneously dispersed magnetic iron-oxide nanoparticles and poly(methyl methacrylate)

• Sašo Gyergyek,
• David Pahovnik,
• Ema Žagar,
• Alenka Mertelj,
• Rok Kostanjšek,
• Miloš Beković,
• Marko Jagodič,
• Heinrich Hofmann and
• Darko Makovec

Beilstein J. Nanotechnol. 2018, 9, 1613–1622, doi:10.3762/bjnano.9.153

• nanoparticles. Additionally, the sPMMA sample was measured. In this case the signal was weak so the autocorrelation function was acquired at a low angle, i.e., at a small scattering vector that makes it possible to probe the fast dynamics of small polymer chains. The resulting distribution function of the

Interaction-tailored organization of large-area colloidal assemblies

• Silvia Rizzato,
• Elisabetta Primiceri,
• Anna Grazia Monteduro,
• Adriano Colombelli,
• Angelo Leo,
• Maria Grazia Manera,
• Roberto Rella and
• Giuseppe Maruccio

Beilstein J. Nanotechnol. 2018, 9, 1582–1593, doi:10.3762/bjnano.9.150

• accommodated in the assembly once the maximum packing limit is obtained The nanosphere template formation can be better understood if we analyze the dynamics of the assembly process in its three phases more in depth. In the first 3D assembly phase, when the substrate is totally immersed in the nanosphere

Photoluminescence of CdSe/ZnS quantum dots in nematic liquid crystals in electric fields

• Margarita A. Kurochkina,
• Elena A. Konshina and
• Daria Khmelevskaia

Beilstein J. Nanotechnol. 2018, 9, 1544–1549, doi:10.3762/bjnano.9.145

• spectroscopy is a quantitative tool for the analysis of the dynamics of photoexcitation in colloidal semiconductor quantum dots [23]. The decay time in the active LC matrix increases by a factor of 3.4 and then begins to decrease with the reorientation of LC molecules to a vertical position due to the increase

Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

• Daniel Hiller,
• Julian López-Vidrier,
• Keita Nomoto,
• Michael Wahl,
• Wolfgang Bock,
• Tomáš Chlouba,
• František Trojánek,
• Sebastian Gutsch,
• Margit Zacharias,
• Dirk König,
• Petr Malý and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2018, 9, 1501–1511, doi:10.3762/bjnano.9.141

• electron microscope. PL was measured using a LN2-cooled CCD camera attached to a single grating monochromator with excitation of a HeCd laser (325 nm line). Low-temperature PL spectra were measured from 5 to 300 K using a single-window continuous-flow liquid-He cryostat. TT-dynamics were measured in a

• different samples. In Figure 5 we report the transient transmission dynamics of samples with 4.5 nm Si NCs made of (a) SRON:P with 0.71 atom % P and (b) SRO:B with 1.32 atom % B, i.e., samples with substantial incorporation of dopant atoms and significant PL quenching. For this measurement the excitation

• SRO:B accelerated TT-dynamics exist. When fitting the curves, best results are obtained for a two-exponential fit where the fast component τ1 ≈ 0.5 … 1.5 ps for all samples is attributed to ultrafast carrier trapping and thermalization events. The long component τ2 is associated with the actual Auger

Excitation of nonradiating magnetic anapole states with azimuthally polarized vector beams

• Aristeidis G. Lamprianidis and
• Andrey E. Miroshnichenko

Beilstein J. Nanotechnol. 2018, 9, 1478–1490, doi:10.3762/bjnano.9.139

• , acting on the input vector of the system, instead of acting upon the inner dynamics of the system, i.e., its transfer function, the geometry of the particle, is an alternative way of designing the output of the system, i.e., the scattering response of the particle. The T-matrix method reveals the inner

• dynamics of the scattering system. By determining the multipolar content of the field scattered by the particle one has immediate knowledge of its far-field radiation pattern as well. This means that one readily knows its behavior as a nanoantenna. Hence, apart from being useful for analytical purposes, it

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

• suggest that the combination of molecular dynamics ReaxFF simulations and blind docking techniques can be used as an explorative tool prior to experiments, which is useful for rational design of new drug delivery systems. Keywords: drug delivery; PEGylated nanoparticle; PLA; polymeric nanoparticle

• descriptions using computational methodologies still are not totally addressed. Wang et al. [30] carried out dissipative particle dynamics (DPD) simulations to study the PEG–PLA–PEG/paclitaxel delivery system. The results showed a spherical micelle with the drug inside and polymer chains distributed on the

• , cilostazol [32][33]. PEG chains typically create an interface between the NP core (PLA) and the hydrophilic environment, where the drug encapsulation is largely dependent on the intrinsic affinity between the drug and the PLA core [31]. All-atom molecular dynamics (MD) simulations were performed using the

Induced smectic phase in binary mixtures of twist-bend nematogens

• Anamarija Knežević,
• Irena Dokli,
• Marin Sapunar,
• Suzana Šegota,
• Ute Baumeister and
• Andreja Lesac

Beilstein J. Nanotechnol. 2018, 9, 1297–1307, doi:10.3762/bjnano.9.122

• investigate how conformational disorder of terminal chains might affect induction of the smectic phase we performed a molecular dynamics simulation of BB at 80 K with a time step of 1 fs for a total duration of 10 ps using the Turbomole program package [48] at the PBE/def2-TZVP level of theory using the RI

• approximation [49]. The dynamics were performed in the molecular frame, the centre of mass of the molecule was kept at the origin of the coordinate system and the molecule was rotated to satisfy the Eckart conditions. The geometry of the entire molecule was varied during the simulation, and discrete conformers

• were sampled every 0.2 ps from the dynamics. The sampled geometries are shown in Figure 9a. The snapshots are aligned to maximize the overlap of the benzene ring of each geometry. In this way, the motion of the alkyl chain during the dynamics can be seen clearly. Both the all-trans conformer and

Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

• Yuri P. Panarin,
• Sithara P. Sreenilayam,
• Jagdish K. Vij,
• Anne Lehmann and
• Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

• compounds, two relaxation processes are identified and assigned to (i) collective dynamics of molecules in nanometer-sized cybotactic clusters and (ii) individual molecular relaxations, in the ascending order of frequency of the probe field. The temperature and the bias electric field dependence of the

• Kirkwood correlation factor [56]. In that study [48] they used the reasoning that the relaxation time and the dielectric strength of the short-range polar correlations are proportional to the correlation length or the cluster size. The molecular mode corresponded to the dynamics of individual molecules

• intensity increases as the temperature is reduced. Considering that polar and biaxial cybotactic clusters in the nematic phase exist, the lower frequency relaxation process is governed by the director fluctuations of molecules in clusters, whereas the higher frequency mode is associated with the dynamics of

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• 10.3762/bjnano.9.119 Abstract Kelvin probe force microscopy (KPFM) has been used for the characterization of metals, insulators, and semiconducting materials on the nanometer scale. Especially in semiconductors, the charge dynamics are of high interest. Recently, several techniques for time-resolved

• potential, which contains information about the involved charge carrier dynamics. Here, we show that such measurements are prone to artifacts due to frequency mixing, by performing numerical dynamics simulations of the cantilever oscillation in KPFM subjected to a bias-modulated signal. For square bias

• match the results of the numerical dynamics simulations. Small differences are observed that can be attributed to transients and higher-order Fourier components, as a consequence of the intricate nature of the cantilever driving forces. These results are corroborated by experimental measurements on a

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• insight into the fundamental origin of sliding friction. Results: Using molecular dynamics we investigate frictional properties of aluminum and palladium nanoparticles deposited on a graphene layer. We study the time evolution of the total momentum of the system, the total and potential energies, the

• interface between the slider and the substrate, which usually lead to an increase in friction with time. Modern rate-and-state models for rough contacts predict that aging does not only influence the transition from static contact to sliding, but affects the overall sliding dynamics. The complex nature of

• the friction dynamics of metallic nanoparticles [14] makes it virtually impossible to construct a general and reliable analytical theory of the phenomena under consideration. Therefore, computer modeling, in particular molecular dynamics (MD), is a useful tool for the theoretical study of friction and

Heterostuctures of 4-(chloromethyl)phenyltrichlorosilane and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine prepared on Si(111) using particle lithography: Nanoscale characterization of the main steps of nanopatterning

• Phillip C. Chambers and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2018, 9, 1211–1219, doi:10.3762/bjnano.9.112

• investigation [2][3][4][5][6]. The dynamics and advantages of supramolecular compounds of porphyrins within devices and in fabricated materials are relevant for molecular studies [7][8]. Properties of supramolecular films with porphyrins can be investigated with approaches such as non-linear optics [9

Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

• Anulekha De,
• Sucheta Mondal,
• Sourav Sahoo,
• Saswati Barman,
• Yoshichika Otani,
• Rajib Kumar Mitra and
• Anjan Barman

Beilstein J. Nanotechnol. 2018, 9, 1123–1134, doi:10.3762/bjnano.9.104

• for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 106, India 10.3762/bjnano.9.104 Abstract Ferromagnetic antidot arrays have emerged as a system of tremendous interest due to their interesting spin configuration and dynamics as well as their potential applications in magnetic storage

• , memory, logic, communications and sensing devices. Here, we report experimental and numerical investigation of ultrafast magnetization dynamics in a new type of antidot lattice in the form of triangular-shaped Ni80Fe20 antidots arranged in a hexagonal array. Time-resolved magneto-optical Kerr effect and

• magnetic metamaterials, known as magnonic crystals (MCs), which have great potential for technological applications and fundamental research [1][2]. Investigation and tailoring of the magnetization dynamics in ferromagnetic nanodots [3][4], nanowires [5] and antidots [6][7][8] have fuelled considerable

Imaging of viscoelastic soft matter with small indentation using higher eigenmodes in single-eigenmode amplitude-modulation atomic force microscopy

• Miead Nikfarjam,
• Enrique A. López-Guerra,
• Santiago D. Solares and
• Babak Eslami

Beilstein J. Nanotechnol. 2018, 9, 1116–1122, doi:10.3762/bjnano.9.103

• amplitude of the oscillatory excitation force. This equation indicates that the relevance of the tip–sample forces to the eigenmode dynamics can be diminished or magnified by adjusting the product kA0. Thus, if the forces are not dependent on the tip velocity, higher eigenmodes will lead to greater sample

• smaller indentations. Results and Discussion Numerical results A numerical study was performed simulating a parabolic tip penetrating a polyisobutylene half-space. The dynamics of the cantilever tip are assumed to be mainly contained in the lower modes and therefore we included only the contribution of

• phenomenon. To model the dynamics of the cantilever, a system of three ordinary differential equations was used, in which each equation corresponds to one eigenmode of the cantilever (assuming the dynamics are mainly contained in the first three eigenmodes) [28]. The equations are solved numerically as

Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg_1−xCd_xTe

• Alexandra V. Galeeva,
• Alexey I. Artamkin,
• Alexey S. Kazakov,
• Sergey N. Danilov,
• Sergey A. Dvoretskiy,
• Nikolay N. Mikhailov,
• Ludmila I. Ryabova and
• Dmitry R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 1035–1039, doi:10.3762/bjnano.9.96

• carrier transport. Laser terahertz probing is known to be a powerful tool that may provide an insight into the electron dynamics in semiconductors, particularly, in topological insulators [9][10][11]. Study of non-equilibrium processes in Hg1−xCdxTe in the terahertz spectral range is additionally

Fatigue crack growth characteristics of Fe and Ni under cyclic loading using a quasi-continuum method

• Ren-Zheng Qiu,
• Yi-Chen Lin and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2018, 9, 1000–1014, doi:10.3762/bjnano.9.93

• , strong materials. Considerable attention has been focused on the investigation of the fatigue crack growth behavior in single crystals under cyclic loading using molecular dynamics (MD), which is an effective tool for analyzing the mechanical deformation and mechanical properties of materials at the

Scanning speed phenomenon in contact-resonance atomic force microscopy

• Christopher C. Glover,
• Jason P. Killgore and
• Ryan C. Tung

Beilstein J. Nanotechnol. 2018, 9, 945–952, doi:10.3762/bjnano.9.87

• phenomenon was not observed in the regime suggests that the additional water layers have changed the dynamics of the tip–sample interaction. Furthermore, higher adhesion forces found on mica at 70% RH might change the threshold speed needed to achieve hydrodynamic lift. Conclusion This work has shown the

• hydrodynamic theory. Further research must be conducted to study the effect that a thin, highly ordered, viscous water layer has on the dynamics of the tip–sample contact at various relative humidity and on hydrophilic and hydrophobic samples. Hydrodynamic lubrication phenomenon. (a) The AFM tip is in intimate

Optical orientation of nematic liquid crystal droplets via photoisomerization of an azodendrimer dopant

• Sergey A. Shvetsov,
• Alexander V. Emelyanenko,
• Natalia I. Boiko,
• Alexander S. Zolot'ko,
• Yan-Song Zhang,
• Jui-Hsiang Liu and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 870–879, doi:10.3762/bjnano.9.81

• Strans Let us consider the dynamics of transcis photoisomerization processes of azobenzene compounds. First, for simplicity, the influence of light on an isotropic solution of azobenzene compound will be analyzed. The relative change of Xcis (the ratio between cis isomer concentration Ncis and total

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• NPs kills bacteria much less efficiently yielding a survival ratio of 0.77–0.79 after 120 min (see Figure 5). Antibacterial efficiency of the samples with NPs but no UV illumination is very small showing a survival ratio of 0.84–0.93 (Figure 5). The dynamics of the antibacterial effect of type-2

• deactivating the bacteria are different for semiconducting TiOx and metallic Cu, the dynamics of bactericidal efficiency is also found to be different. Samples with TiOx NPs demonstrate a very good capability to be reused a number of times. Among them, the samples of type 3 (in-flight oxidation of Ti clusters

Towards the third dimension in direct electron beam writing of silver

• Katja Höflich,
• Jakub Mateusz Jurczyk,
• Katarzyna Madajska,
• Maximilian Götz,
• Luisa Berger,
• Carlos Guerra-Nuñez,
• Caspar Haverkamp,
• Iwona Szymanska and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 842–849, doi:10.3762/bjnano.9.78

• -volatile part forms the deposit while the volatile rest is pumped out. The dissociation is a complex process influenced by the local dynamics of the precursor molecules and induced by electrons with their specific, yet mostly unknown, cross-sections for the respective energy ranges and molecule bonds to

• precursor dynamics, especially by adsorption and by diffusion of the molecules, and by the actual precursor flux. Upon vertical growth, the size of the interaction volume where secondary electrons are generated, significantly decreases since it moves upwards into the deposit [8]. If the vertical growth rate

• silver content of 74 atom % for AgO2F5Prop is remarkable but accompanied by a detectable amount of the fluorine incorporated into the deposit. The amount of fluorine in the deposit roughly equals the amount of incorporated carbon. To elucidate the precursor dynamics, spot exposures using a beam current

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices

• T. Anh Thu Do,
• Truong Giang Ho,
• Thu Hoai Bui,
• Quang Ngan Pham,
• Hong Thai Giang,
• Thi Thu Do,
• Duc Van Nguyen and
• Dai Lam Tran

Beilstein J. Nanotechnol. 2018, 9, 771–779, doi:10.3762/bjnano.9.70

• . Keywords: Au-decorated ZnO; carrier dynamics; gas sensors; photocatalyst; SPR effect; Introduction Inorganic transition metal oxide sensor devices have attracted attention in particular for improving gas sensing, energy conversion, electronics, photocatalysis and optoelectronic devices [1][2][3][4]. Among

Dynamics and fragmentation mechanism of (C₅H₄CH₃)Pt(CH₃)₃ on SiO₂ surfaces

• Kaliappan Muthukumar,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2018, 9, 711–720, doi:10.3762/bjnano.9.66

• /bjnano.9.66 Abstract The interaction of trimethyl(methylcyclopentadienyl)platinum(IV) ((C5H4CH3)Pt(CH3)3) molecules on fully and partially hydroxylated SiO2 surfaces, as well as the dynamics of this interaction were investigated using density functional theory (DFT) and finite temperature DFT-based

• molecular dynamics simulations. Fully and partially hydroxylated surfaces represent substrates before and after electron beam treatment and this study examines the role of electron beam pretreatment on the substrates in the initial stages of precursor dissociation and formation of Pt deposits. Our

• have made a series of DFT studies in which we considered fully and partially hydroxylated SiO2 surfaces as a representative for untreated and electron beam pretreated substrates and investigated the adsorption [9][10] and dynamics of several carbonyl precursors [11]. (C5H4CH3)Pt(CH3)3, in which Pt