Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders

• Wojciech Szmyt,
• Carlos Guerra and
• Ivo Utke

Beilstein J. Nanotechnol. 2017, 8, 64–73, doi:10.3762/bjnano.8.7

• direction. Laterally, the diffusion is two-dimensional (k = 2). Therefore it is equal to which is half the value of the longitudinal one, and, effectively, the diffusion is anisotropic. The anisotropic diffusion is modelled with the three-dimensional diffusion equation where t is time, is the gradient

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• -Voigt function was chosen as profile function [55]. The background was refined by adjusting the height of preselected points for linear interpolation modeled and the spherical harmonics correction for an anisotropic peak broadening was applied. Afterwards, the hydroxide part of the structure was entered

Precise in situ etch depth control of multilayered III−V semiconductor samples with reflectance anisotropy spectroscopy (RAS) equipment

• Ann-Kathrin Kleinschmidt,
• Lars Barzen,
• Johannes Strassner,
• Christoph Doering,
• Henning Fouckhardt,
• Wolfgang Bock,
• Michael Wahl and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2016, 7, 1783–1793, doi:10.3762/bjnano.7.171

• -etching is an essential step of many lithographic processes, e.g., in semiconductor device fabrication, and offers several advantages over wet-etching as for instance the opportunity to achieve anisotropic etching and vertical etch flanks [10][11]. As the requirements for accuracy in microfabrication

Morphology of SiO₂ films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

• Volodymyr Tkachenko,
• Antigone Marino,
• Eva Otón,
• Noureddine Bennis and
• Josè Manuel Otón

Beilstein J. Nanotechnol. 2016, 7, 1743–1748, doi:10.3762/bjnano.7.167

• account birefringence while Gospodyn et al. [18] studied anisotropic refractive index as well. However, information on the index ellipsoid orientation of obliquely evaporated SiO2 films is still missing. The connection between SiO2 column tilt and pretilt of LCs is not clarified yet. Most papers focused

• , and Jps are the corresponding elements of the matrices with rpp, rss, rps, rsp (tpp, tss, tps, tsp) representing the reflection (transmission) coefficients for p-, s-, and cross-polarizations, respectively. GE is a technique that measures thickness and dielectric constants of anisotropic thin films

• system, whose coordinates (x',y',z') are chosen with the y' axis normal to the incidence plane, and the z' axis normal to the sample plane. The second one is the sample reference system, whose coordinates (x,y,z) diagonalize the anisotropic permittivity tensor. These two systems are related to each other

Effect of tetramethylammonium hydroxide/isopropyl alcohol wet etching on geometry and surface roughness of silicon nanowires fabricated by AFM lithography

• Siti Noorhaniah Yusoh and
• Khatijah Aisha Yaacob

Beilstein J. Nanotechnol. 2016, 7, 1461–1470, doi:10.3762/bjnano.7.138

• substrate itself. Wet etching can be either isotropic or anisotropic, depending on the silicon wafer orientation and the type of etchant being used [5][6]. In isotropic etching, the etchant removes the material uniformly in all directions [7], whereas in anisotropic etching, the material is removed

• uniformly in the vertical direction only. Anisotropic wet etching is mostly used to fabricate simple microstructures and nanostructures on a single crystal SOI wafer [8]. Tetramethylammonium hydroxide (TMAH) [9][10][11], potassium hydroxide (KOH) [12], sodium hydroxide (NaOH) [13], ethylenediamine

• potassium hydroxide solution that has become a popular anisotropic etchant because of its good etching performance and lack of toxicity. However, KOH is not CMOS compatible because of the mobile K+ ion contamination [16]. By contrast, TMAH has attracted the interest of researchers because of its simple

Tunable longitudinal modes in extended silver nanoparticle assemblies

• Serene S. Bayram,
• Klas Lindfors and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2016, 7, 1219–1228, doi:10.3762/bjnano.7.113

• with tunable properties are of great interest for a wide range of applications. The self-assembly of simple nanoparticle building blocks could provide an inexpensive means to achieve this goal. Here, we generate extended anisotropic silver nanoparticle assemblies in solution using controlled amounts of

• these unprecedented anisotropic structures. Our results show a correlation between the chain nature of the assembly and the generation of spectral anisotropy. Deuterating the ligand further enhances the anisotropic signal by triggering more compact aggregates and reveals the importance of solvent

• Raman spectroscopic enhancement [22]. Although AgNPs have been assembled into higher-order structures via multiple strategies [23][24][25][26], none of the resulting structures exhibit highly anisotropic spectral signatures, i.e., well-resolved isotropic/axial and anisotropic/longitudinal SPR bands that

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• property changes anisotropic [135]. The enhancement is then maximum along the orientation axis of the filler and minimum in the transverse direction [2]. There are two factors that govern the degree of CNT alignment in the polymer matrix: (1) the diameter of CNTs, and (2) the CNT content. Smaller diameters

• and lower content improves the CNT alignment [40]. The fiber alignment can be improved by fiber spinning. It yields anisotropic composite properties, but an improvement of the mechanical properties of the CNT–polymer nanocomposites was shown [35]. Haggenmuller et al. used fiber spinning to align SWNTs

• , the manufacturing of nanocomposites should be carried out at the lowest possible temperature. Elevated temperatures lower the viscosity, which results in CNT scattering. CNTs can be aligned magnetically because of their anisotropic magnetic susceptibility [134]. Magnetic fields may be applied during

An ellipsometric approach towards the description of inhomogeneous polymer-based Langmuir layers

• Falko O. Rottke,
• Burkhard Schulz,
• Klaus Richau,
• Karl Kratz and
• Andreas Lendlein

Beilstein J. Nanotechnol. 2016, 7, 1156–1165, doi:10.3762/bjnano.7.107

• , inhomogeneous or anisotropic. Considering this, the overall complex reflection coefficients are measured as a function of the angle of incidence, φ, and wavelength, λ, as where NSubstrate are the optical constants of the substrate, nAmbient is the refractive index of the ambient medium, and nlayer, klayer and

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• -based molecules could potentially be utilized in building molecular-scale quantum spin memory and processors. Taking all these points into consideration, one idea would be to step further and to introduce anisotropic lanthanide ions into these phenalenyl-based complexes with the focus on their

• work is currently in progress. During the submission of this work, a few interesting Dy(III)-SIMs with D5h symmetry have been reported [60][61][62]. The three examples all show a fascinating anisotropic barrier over 500 K as a result of the higher order symmetry around Dy(III) ion. This is related to

• = 0.71073 Å). Structure solution and refinement against F2 were carried out using shelxs and shelxl software. Refinement was performed with anisotropic temperature factors for all non-hydrogen atoms (disordered atoms were refined isotropically); hydrogen atoms were calculated on idealized positions

Large-scale fabrication of achiral plasmonic metamaterials with giant chiroptical response

• Morten Slyngborg,
• Yao-Chung Tsao and
• Peter Fojan

Beilstein J. Nanotechnol. 2016, 7, 914–925, doi:10.3762/bjnano.7.83

• factor [10] (ΔΔλ) of the shifts of the right-handed spectrum compared to the left-handed spectrum (ΔΔλ = Δλright − Δλleft) is an indication of an anisotropic adsorption (Table 3) [10]. Whereas a perfect isotropic adsorption would result in a ΔΔλ value of zero. Interestingly, the adsorption of the two

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• , Universidad Carlos III de Madrid, Butarque 15, Leganés, 28911, Spain, CNR-ISASI and Physics Department, University of Naples Federico II, Via Cinthia Monte S. Angelo, 80126, Naples, Italy 10.3762/bjnano.7.74 Abstract Single-wall carbon nanotubes (SWCNT) are anisotropic nanoparticles that can cause

• ; Introduction Single-wall carbon nanotubes (SWCNTs) are highly anisotropic nanoparticles (NPs) formed from a single, wrapped graphene sheet. SWCNTs may be metallic or semiconductive, depending on the rolling angle (chirality) and diameter [1]. The SWCNT one-dimensional structure leads to an anisotropic

• conductivity, where the charge transport is favored along the longitudinal axis [2]. Liquid crystals (LCs) are self-organized anisotropic fluids, well-known for their use in flat panel mobile, PC, and TV displays. Besides consumer electronic products, LCs are employed in many photonic devices such as spatial

Microscopic characterization of Fe nanoparticles formed on SrTiO₃(001) and SrTiO₃(110) surfaces

• Miyoko Tanaka

Beilstein J. Nanotechnol. 2016, 7, 817–824, doi:10.3762/bjnano.7.73

• be larger than the nanoparticle sizes observed here [56][57]. Although a more precise evaluation of kinetic factors and of the possibility of anisotropic growth should be made, it is not unreasonable to suppose that ideal nanoparticles have a simple Wulff shape. And nanoparticles with OR1 and OR2 can

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• application of micromagnetic simulations leads to a detailed understanding of the switching modes of specific sample geometries. We highlight that even anisotropic magnetoresistance curves can be simulated in good agreement with experiments. In the second part, we first focus on the detailed discussion of the

• × 2 × 10 nm3) [28]. As will be shown later in connection with the anisotropic magnetoresistance (AMR) the major part of the total resistance arises from the 2.5 × 20 µm2 FIB-cut constriction. But still the continuous antidot film surrounding the channel influences the magnetic switching via dipolar

• <0.75 The intrinsic domain structure in antidot arrays always stands in close relation to the orientation of the antidot lattice. According to the hexagonal lattice of holes, we expect a 6-fold in-plane anisotropy. In this section, we investigate the anisotropic switching for a ratio d/a ≈ 0.5, i.e

Orientation of FePt nanoparticles on top of a-SiO₂/Si(001), MgO(001) and sapphire(0001): effect of thermal treatments and influence of substrate and particle size

• Martin Schilling,
• Paul Ziemann,
• Zaoli Zhang,
• Johannes Biskupek,
• Ute Kaiser and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2016, 7, 591–604, doi:10.3762/bjnano.7.52

• films and oriented growth of nanoparticles (NPs) on single crystal supports are of general interest for improved physical and chemical properties especially of anisotropic materials. In the case of FePt, the main focus lies on its highly anisotropic magnetic behavior and its catalytic activity, both due

• desired L10 phase by an additional annealing step. Accompanying this structural transformation, one observes highly anisotropic magnetic properties leading to, e.g., huge coercive fields in the Tesla range [4][8][9][10][11]. While ultrathin FePt films usually exhibit large magnetic domains, the use of

• superstructure {001} and {011} peaks for L10-ordered FePt NPs (as compared to the disordered A1 structure) gives direct proof for the formation of the highly anisotropic L10 phase. Results and Discussion In the following first part we present a HRTEM study of a few FePt NPs on a MgO(001) substrate proving the

Determination of Young’s modulus of Sb₂S₃ nanowires by in situ resonance and bending methods

• Liga Jasulaneca,
• Raimonds Meija,
• Alexander I. Livshits,
• Juris Prikulis,
• Subhajit Biswas,
• Justin D. Holmes and
• Donats Erts

Beilstein J. Nanotechnol. 2016, 7, 278–283, doi:10.3762/bjnano.7.25

• sulfide; in situ; mechanical properties; nanowires; Young’s modulus; Introduction Antimony sulfide or stibnite is a highly anisotropic semiconductor material with potential applications in thermoelectric and optoelectronic [1][2] devices due to its high achievable thermoelectric power and

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• with the presence of hysteresis loops. Keywords: bipyrimidine; diketone; hysteresis; lanthanide; magnetism; Introduction The application of magnetic molecular compounds within molecular electronic devices is combined in the progressive field of spintronics. An anisotropic spin is confined by the

• magnetically anisotropic lanthanide ions can possibly act as basic units of quantum computing, i.e., as qubits. Universal qugates may be engineered by designing one molecule with two interacting lanthanide ions [17]. We are particularly interested in generating dinuclear lanthanide complexes with a bridging

• small decrease at the lowest temperature occurs (leading to a value of 15.1 cm3 K mol−1) (Figure 2). This small downturn could correspond to antiferromagnetic exchange or dipolar interactions between the Gd(III)···Gd(III) ions (see below). Similarly, the anisotropic χMT(T) behavior of the anisotropic

Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

• Nina J. Blumenstein,
• Caroline G. Hofmeister,
• Peter Lindemann,
• Cheng Huang,
• Johannes Baier,
• Andreas Leineweber,
• Stefan Walheim,
• Christof Wöll,
• Thomas Schimmel and
• Joachim Bill

Beilstein J. Nanotechnol. 2016, 7, 102–110, doi:10.3762/bjnano.7.12

• complete ZnO film is formed. The methyl ester can coordinate the polar ZnO crystallites. This in turn can support an oriented attachment of the nanoparticles to the surface and an anisotropic orientation of the entire film, which was observed by XRD (Figure 4) [42][43]. Conclusion ZnO thin films were grown

• anisotropic fashion, forming a compact ZnO film. Experimental Preparation of the PS brush Silicon wafers with a surface orientation of [100] and a native oxide layer with 2–3 nm thickness (Wacker Burghausen, Germany) were used as substrates. Before cleaning them with a CO2 snow jet [44] in order to remove

Surface-enhanced Raman scattering by colloidal CdSe nanocrystal submonolayers fabricated by the Langmuir–Blodgett technique

• Alexander G. Milekhin,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Volodymyr M. Dzhagan,
• Ovidiu D. Gordan,
• Sergey L. Veber,
• Cameliu Himcinschi,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 2388–2395, doi:10.3762/bjnano.6.245

• nanocluster arrays, a dimer array represents an anisotropic plasmonic structure which is characterized by two coupled resonance plasmon modes when excited perpendicular to the structure surface [46]. The longitudinal LSPR mode (which is polarized along the long dimer particle axis) red-shifts with decreasing

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• , shape and crystalline structure of Au NPs in a polymeric matrix are strongly influenced by the reaction temperature. At T = 100 °C and T = 20–50 °C, Au NPs had sizes of 18 and 27 nm, respectively, while at lower temperatures (4–10 °C), they observed anisotropic nanosheets of different shapes within the

• . They reacted AgNO3 and graphene oxide (GO) with TA simultaneously and observed that GO sheets were impregnated with many Ag NPs with diameters up to 20 nm [73]. Kasthuri et al. synthesized anisotropic Au and quasi-spherical Ag NPs using apiin to reduce AgNO3 and HAuCl4 at room temperature within 60 s

Correction: A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2330–2331, doi:10.3762/bjnano.6.239

Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• lengths along the two directions are more similar, as we reported in Table 1. Still the molecule being inherently anisotropic determines the residual azimuthal dichroism reduced to approx. 1 eV. Reporting the initial state contributions in this energy range, the x-direction spectrum has largest

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2161–2172, doi:10.3762/bjnano.6.222

• have an anisotropic, elongated shape. In contrast, the particles of the pure ZnO material are not elongated (see Figure S5, Supporting Information File 1). High-resolution (HR) TEM measurements show the high crystallinity of the single Cl@ZnO nanocrystals (see also Figure S4, Supporting Information

• was seen that the presence of Cl leads to a widening of the ZnO lattice in a,b-direction, and as a consequence anisotropic nanoparticles with preferential growth in c-direction were obtained. The latter result represents an interesting perspective to understand and to control anisotropic particle

Distribution of Pd clusters on ultrathin, epitaxial TiO_x films on Pt₃Ti(111)

• Christian Breinlich,
• Maria Buchholz,
• Marco Moors,
• Tobias Pertram,
• Conrad Becker and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

• Scanning tunnelling microscopy (STM) was used to investigate the nucleation and growth of palladium clusters on two different, ultrathin, epitaxial, titania films grown on a Pt3Ti(111) surface. The first oxide phase, z'-TiOx, is anisotropic and consists of parallel stripes separated by trenches. Defects

• z'-TiOx phase on Pt(111) [15]. The observed arrangement of the clusters is a consequence of the diffusion behaviour of the deposited metal atoms on this structurally anisotropic oxide surface. On the one hand the palladium–oxygen interaction is not very strong, permitting metal atom mobility at room

• temperature [19]. On the other hand, the trenches (1D depressions) guide the Pd atom diffusion preferentially along the grooves. Such anisotropic diffusion behaviour has been observed in the inverse system, namely the oxidation of Pd(110) leading to the growth of pronounced, elongated, oxide islands [20

Lower nanometer-scale size limit for the deformation of a metallic glass by shear transformations revealed by quantitative AFM indentation

• Arnaud Caron and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2015, 6, 1721–1732, doi:10.3762/bjnano.6.176

• Pt57.5Cu14.7Ni5.3P22.5 metallic glass. We attribute the distortion of the triangle to an anisotropic elastic relaxation of Pt(111). Figure 5 shows the load dependence of the pile-up volume Vpile up and the projected area Ap for Pt(111) and Pt57.5Cu14.7Ni5.3P22.5 metallic glass as extracted from nc-AFM images of indents

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• al. commented that extended holes (rather than a knock-on vacancy) grow over a wide range from 20 to 100 keV, or even below 20 keV. A mechanism of beam-induced etching with residual water or oxygen in the system is therefore suggested [40]. The strong anisotropic tubular structure of CNTs leads to an