Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes

• Sascha Koch,
• Christopher D. Kaiser,
• Paul Penner,
• Michael Barclay,
• Lena Frommeyer,
• Daniel Emmrich,
• Patrick Stohmann,
• Tarek Abu-Husein,
• Andreas Terfort,
• D. Howard Fairbrother,
• Oddur Ingólfsson and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2017, 8, 2562–2571, doi:10.3762/bjnano.8.256

• process in the gas phase (Figure 1) shows that the relative difference between 2-Cl-BPT and 2-Br-BPT is less clear in the SAMs. This is to be expected due to the different conditions in the condensed phase as compared to the gas phase, for example, different temperatures and additional energy dissipation

• channels introduced at the surface as compared to single collision conditions in the gas phase. Furthermore, the gas phase studies shown in Figure 1 show only the halogen loss through DEA. The XPS data on the other hand show the total dehalogenation, independent of the underlying process, that is, DI, ND

• irradiation as compared to gas-phase molecules under single collision conditions. However, though qualitative in nature, our experiments show that the electron-induced dehalogenation process is substantially more efficient in the 2-I-BPT SAMs than the 2-Cl-BPT and 2-Br-BPT SAMs. It is reasonable to assume

Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

• Julie A. Spencer,
• Michael Barclay,
• Miranda J. Gallagher,
• Robert Winkler,
• Ilyas Unlu,
• Yung-Chien Wu,
• Harald Plank,
• Lisa McElwee-White and
• D. Howard Fairbrother

Beilstein J. Nanotechnol. 2017, 8, 2410–2424, doi:10.3762/bjnano.8.240

• studies, the removal of carbon is often emphasized due to its prevalence as an impurity in the deposited nanostructures. One of the most widely studied non-thermal purification strategies is electron beam induced purification, typically performed in the presence of a gas-phase species, usually either

• oxygen or water. In these techniques, the electron beam dissociates gas phase reactants to yield reactive oxygen species, which then convert deposited carbon into volatile compounds such as CO and CO2 [16][17][18][19]. Villamor et al. [20] observed that either by post deposition electron beam processing

• ], where purification is ascribed at least in part to a laser-induced oxidation process. In this technique, the reactive oxygen species are produced from gas phase reactants, such as oxygen, that are deliberately introduced. Sequential cycles of electron-induced deposition are followed by laser-induced

Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane: the role of dissociative ionization and dissociative electron attachment in the deposition process

• Ragesh Kumar T P,
• Sangeetha Hari,
• Krishna K Damodaran,
• Oddur Ingólfsson and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2017, 8, 2376–2388, doi:10.3762/bjnano.8.237

• and we compare the proximity effect observed for these compounds. The two precursors show similar behaviour with regards to fragmentation through dissociative ionization in the gas phase under single-collision conditions. However, while DCSCH shows appreciable cross sections with regards to

• into applicable design criteria for superior FEBID precursors. In this context a considerable number of gas-phase studies have been conducted, mainly on DEA and DI of different organometallic FEBID precursors. Complementary surface science studies have been carried out to better relate the gas-phase

• current experiments are thus largely confined to DEA and DI of FEBID precursors. Despite this, significant insight has been provided by the gas-phase and surface-science studies and in individual cases a distinction between the role of DEA and DI in the deposition process has been achieved

Dissociative electron attachment to coordination complexes of chromium: chromium(0) hexacarbonyl and benzene-chromium(0) tricarbonyl

• Janina Kopyra,
• Paulina Maciejewska and
• Jelena Maljković

Beilstein J. Nanotechnol. 2017, 8, 2257–2263, doi:10.3762/bjnano.8.225

• we report the results of dissociative electron attachment (DEA) to gas-phase chromium(0) hexacarbonyl (Cr(CO)6) and benzene-chromium(0) tricarbonyl ((η6-C6H6)Cr(CO)3) in the energy range of 0–12 eV. Measurements have been performed utilizing an electron-molecular crossed beam setup. It was found that

• ; dissociative electron attachment; gas phase reactions; mass spectrometry; Introduction Organometallic compounds are a large class of compounds with numerous applications such as homogeneous catalysts for the synthesis of fine chemicals or even enantiomerically pure products used in the pharmaceutical industry

• primary beam. To date there have been several papers devoted to the studies of the interaction of low energy electrons with gas-phase organometallic complexes. Particular attention has been paid to the compounds containing monodentate (e.g., carbonyl [12][13][14], trifluorophosphine [11][15], chloride [16

Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• beam impinging on the surface where dissociative electron attachment (DEA) processes are relevant, although at those energies electron impact excitations yielding neutral dissociation are prevalent in detriment to DEA [25]. Gas-phase DEA studies in the electron energy range from 0 to 14 eV reported by

Suppression of low-energy dissociative electron attachment in Fe(CO)₅ upon clustering

• Jozef Lengyel,
• Peter Papp,
• Štefan Matejčík,
• Jaroslav Kočišek,
• Michal Fárník and
• Juraj Fedor

Beilstein J. Nanotechnol. 2017, 8, 2200–2207, doi:10.3762/bjnano.8.219

• electron attachment in isolated Fe(CO)5. Keywords: aggregation effects; dissociative electron attachment; FEBID; iron pentacarbonyl; long-range interactions; Introduction In recent years a number of gas-phase studies on molecules that are commonly used as precursors in electron-induced nanofabrication

• [12][13]. The environment can thus both enhance and suppress the low-energy DEA reactions and it is difficult to assess its effect a priori. Clusters represent an ideal tool for studying the effect of an environment since they allow for using the same experimental approach as the gas phase studies

• (crossed electron – target beam with product mass analysis) and enable direct comparisons for various aggregation degrees (gas phase – small clusters – large clusters). When compared to the surface-based ion desorption approach, cluster-beam experiments do not suffer from desorption probability problem

Angstrom-scale flatness using selective nanoscale etching

• Takashi Yatsui,
• Hiroshi Saito and
• Katsuyuki Nobusada

Beilstein J. Nanotechnol. 2017, 8, 2181–2185, doi:10.3762/bjnano.8.217

• . To understand the differences of the etching properties, we estimated the mean free paths (MFPs) of Cl2 and ClO−. The MFP of Cl2 in the gas phase is on the order of 10 μm (≈RT/√2NAπd2P [15], where R = 8.31 J K−1mol−1, T = 300 K, NA = 6.02 × 1023 mol−1, d = 200 × 10−12 m (the diameter of a Cl2

• -field dry etching, because of a greater MFP value of the gas phase that exceeds the scanning area, the dissociated atoms can react only when they are located at the protrusions where the ONF generated. Conclusion Using two-dimensional Fourier analysis, we found that near-field etching is effective for

Ester formation at the liquid–solid interface

• Nguyen T. N. Ha,
• Thiruvancheril G. Gopakumar,
• Nguyen D. C. Yen,
• Carola Mende,
• Lars Smykalla,
• Maik Schlesinger,
• Roy Buschbeck,
• Tobias Rüffer,
• Heinrich Lang,
• Michael Mehring and
• Michael Hietschold

Beilstein J. Nanotechnol. 2017, 8, 2139–2150, doi:10.3762/bjnano.8.213

• products. Scheme 1 shows a proposed reversible esterification route with a dimer intermediate of TMA and undecanol to TMA–monoundecyl ester. The possible formation of TMA–monoundecyl ester and water from a TMA–undecanol dimer in the gas phase (see energy diagram in Figure 8) was simulated. To simulate the

• should be almost parallel to the A axis. Energy diagram of the reaction path of TMA and undecanol to form TMA–undecyl ester and water for isolated molecules (gas phase) calculated using DFT (PBE). The corresponding geometry of the molecules in the simulation is shown for each energy point marked in the

Advances and challenges in the field of plasma polymer nanoparticles

• Andrei Choukourov,
• Pavel Pleskunov,
• Daniil Nikitin,
• Valerii Titov,
• Artem Shelemin,
• Mykhailo Vaidulych,
• Anna Kuzminova,
• Pavel Solař,
• Jan Hanuš,
• Jaroslav Kousal,
• Ondřej Kylián,
• Danka Slavínská and
• Hynek Biederman

Beilstein J. Nanotechnol. 2017, 8, 2002–2014, doi:10.3762/bjnano.8.200

• used as precursors for plasma polymerization [43][44][45][46][47][48][49][50][51][52]. Depending on the experimental conditions, plasma polymerization can be forced to proceed in a gas phase which results in the formation of NPs of different chemical and physical properties and with different size

• coagulation is therefore suppressed by Coulomb repulsion, and further NP growth proceeds by accretion via the accumulation of polymer-forming neutral species (radicals) and positive ions from the gas phase. The resultant plasma polymer NPs have a spherical symmetry but can exhibit different morphology

• addition of oxygen. FTIR and XPS (Figure 8a,b) analyses demonstrate the organosilicon character of the NPs produced without O2 and its gradual transfer to the inorganic state with the addition of O2. The gas phase composition can be optimized to produce nearly stoichiometric SiO2 NPs (Figure 7c), which are

Bi-layer sandwich film for antibacterial catheters

• Gerhard Franz,
• Florian Schamberger,
• Hamideh Heidari Zare,
• Sara Felicitas Bröskamp and
• Dieter Jocham

Beilstein J. Nanotechnol. 2017, 8, 1982–2001, doi:10.3762/bjnano.8.199

• of the depositing molecules decreases exponentially with penetration depth not only by diffusion but also by deposition losses, which causes a steeply dropping layer thickness. The reaction can occur in the gas phase as well as during or after the process of condensation (physisorption). By diluting

• gases. Vapor enters through a heated pipe and reacts either in the volume (gas-phase reaction) or on cold surfaces (solid-state reaction) to a polymer by chain-building. To prevent evaporation during the heating ramp (approx. 45 min), which would cause an irreproducible layer thickness, a flow of argon

• lead to unwanted reactions are reduced. These unwanted reactions lead to polymerization and grain formation in the gas phase. Eventually, these grains arrive at the surface, which is clearly revealed by SEM inspection (Figure 17a). Properties of sub-micrometer layers As our interest is focused on very

Enhancement of mechanical and electrical properties of continuous-fiber-reinforced epoxy composites with stacked graphene

• Naum Naveh,
• Olga Shepelev and
• Samuel Kenig

Beilstein J. Nanotechnol. 2017, 8, 1909–1918, doi:10.3762/bjnano.8.191

• -cost conductive alternative [7]. GNPs can be produced by intercalation of the graphitic layers with an appropriate agent followed by exfoliation of the graphite flakes. Exfoliation is obtained by rapid heating resulting in conversion of the intercalant to a gas phase forcing the adjacent graphene

Non-intuitive clustering of 9,10-phenanthrenequinone on Au(111)

• Ryan D. Brown,
• Rebecca C. Quardokus,
• Natalie A. Wasio,
• Jacob P. Petersen,
• Angela M. Silski,
• Steven A. Corcelli and
• S. Alex Kandel

Beilstein J. Nanotechnol. 2017, 8, 1801–1807, doi:10.3762/bjnano.8.181

• other. It is apparent from the original image and the tetramer composite image that within this cluster the molecules orient with the carbonyl groups projecting into the center of this cluster. If considered as a gas-phase species, the observed tetramer conformation positions the net dipole of each

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy

• Petra Fiala,
• Daniel Göhler,
• Benno Wessely,
• Michael Stintz,
• Giovanni Mattia Lazzerini and
• Andrew Yacoot

Beilstein J. Nanotechnol. 2017, 8, 1774–1785, doi:10.3762/bjnano.8.179

• procedure (Plasma Prep II, SPI Supplies) was chosen. A study of cleaning methods for silicon has been undertaken in [15]. The application of conditioned samples on the conditioned substrates were performed by four liquid phase preparation methods and two gas phase preparation methods as summarised in Table

• be deposited individually in case of a corresponding initial concentration. The deposition rate can be set effectively and reproducibly via the residence time in the suspension. Gas phase preparation Over the last few decades several devices for the deposition of airborne particles on substrates have

• -conditioned, gas phase preparation methods require two additional steps, i.e., aerosol generation (e.g., atomization) and aerosol conditioning (e.g., classifying, dilution, neutralisation). The most common method for this is the atomization of suspensions with subsequent aerosol drying (e.g., diffusion drying

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• normalized to the total ion signal of all masses detected during each experiment. The point relative to power P = 0 W is representative for the CF4 gas phase, the plasma is not ignited and the CF4 flows in the chamber. The mass spectrum is dominated by the intense signal corresponding to the ionized CF3 (m/z

• different plasma power (the working pressure is set to 10 mTorr). The masses under study are relative to the following ionized species: CF (m/z = 31 amu), CF2 (m/z = 50 amu), CF3 (m/z = 69 amu), and HF (m/z = 20 amu), COF (m/z = 47 amu), COF2 (m/z = 66 amu). b) FTIR spectra acquired during pure CF4 gas

• phase (dotted line) and during CF4 plasma ignited at different power (from 10 to 250 W). The two frames in the figure detail the peaks located at 1286 and 1261 cm−1 for better visualization of the intensity variation. c) Intensities of the FTIR peaks related to CF4 (at 1539 cm−1), CF2 (at 667.4 cm−1

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• with the accompanying chemical reactions, is presented in Figure 1. There is a number of advantages of the parylene technology. First of all, being a gas-phase diffusion-controlled process, it yields smooth pinhole-free conformal coatings with excellent penetration abilities. Second, there are several

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• chemical reactions and from singlet–triplet interconversion in radical pairs, which is sensitive to external magnetic fields and local hyperfine fields of magnetic nuclei. Although experiments have been done in gas phase (see Sections IV.A and V.A of [2] and the references therein) and in solid state (e.g

Adsorption and electronic properties of pentacene on thin dielectric decoupling layers

• Sebastian Koslowski,
• Daniel Rosenblatt,
• Alexander Kabakchiev,
• Klaus Kuhnke,
• Klaus Kern and
• Uta Schlickum

Beilstein J. Nanotechnol. 2017, 8, 1388–1395, doi:10.3762/bjnano.8.140

• demonstrated by the observation of the unperturbed gas-phase-like frontier orbitals of pentacene on this substrate [3]. A weak interaction is nevertheless suggested by the observed shift of the orbital energies of the admolecule [4][7][8]. In scanning tunneling spectroscopy (STS) experiments on pentacene, two

• −2.16 V can be attributed to a bound state with an energy of 6.31 eV and, respectively, the LUMO at 1.2 V to a bound state with an energy of 2.95 eV. These energies can be related to the electron affinity of 1.35 eV [14] and the ionization energy of gas-phase pentacene at 6.58 eV [15]. The deviation of

• the gas-phase energies from the energies found on the surface can be explained by the screening of the underlying substrate during the temporary charging of the molecule [1][17][18]. In our measurements we observe a decrease of the HOMO–LUMO gap by 1.7 eV (i.e., an average shift of 0.85 eV for HOMO

Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

• Martin Börner,
• Laura Blömer,
• Marcus Kischel,
• Peter Richter,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Pablo F. Siles,
• Maria E. N. Fuentes,
• Carlos C. B. Bufon,
• Daniel Grimm,
• Oliver G. Schmidt,
• Daniel Breite,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Nanotechnol. 2017, 8, 1375–1387, doi:10.3762/bjnano.8.139

• according to a protocol developed for the preparation of self-assembled thiol monolayers [59] as the complexes cannot be deposited via the gas phase. They decompose without melting. Thus, clean gold-coated Si wafers were immersed in a 1 × 10−3 M solution of the respective complex in MeCN or CH2Cl2 for 24 h

Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors

• Dario Zappa,
• Angela Bertuna,
• Elisabetta Comini,
• Navpreet Kaur,
• Nicola Poli,
• Veronica Sberveglieri and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2017, 8, 1205–1217, doi:10.3762/bjnano.8.122

• the oxide surface leads to an increase of the number of adsorbed species from the gas phase. This results in an increase of electrical conductance for for p-type materials and, correspondingly, a decrease for n-type materials. This behaviour can be better explained through the following reactions in

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

Surface improvement of organic photoresists using a near-field-dependent etching method

• Felix J. Brandenburg,
• Tomohiro Okamoto,
• Hiroshi Saito,
• Benjamin Leuschel,
• Olivier Soppera and
• Takashi Yatsui

Beilstein J. Nanotechnol. 2017, 8, 784–788, doi:10.3762/bjnano.8.81

• effective in producing atomically flat surfaces in various materials, including GaN [9], glass [10] and even diamond [11] and has shown to be effective on both flat and patterned surfaces. According to theory, the etching effect originates from radical gas-phase components. More precisely, ambient O2

Modeling adsorption of brominated, chlorinated and mixed bromo/chloro-dibenzo-p-dioxins on C₆₀ fullerene using Nano-QSPR

• Piotr Urbaszek,
• Agnieszka Gajewicz,
• Celina Sikorska,
• Maciej Haranczyk and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2017, 8, 752–761, doi:10.3762/bjnano.8.78

• congeners, we observed slightly positive Eads values in calculations and in predictions as well. Please note that all of the calculations were performed at the standard 298.15 K temperature in gas phase. More importantly, the M06-2X functional is one of the best and it is recommended for modeling of weak

• (comparable to the sum of single molecule energies for calculations in a gas phase (at 298.15 K)) may seem doubtful according to Hess’s law (Equation 2). Additionally, it should be highlighted that all of the PXDD@C60 materials are considered to be thermodynamically stable systems, and all of the Hessian

Vapor deposition routes to conformal polymer thin films

• Priya Moni,
• Ahmed Al-Obeidi and
• Karen K. Gleason

Beilstein J. Nanotechnol. 2017, 8, 723–735, doi:10.3762/bjnano.8.76

• polymer film. As seen in Figure 2b, gas phase monomers containing a reactive bond first adsorb on the substrate near room temperature. An initiator, such as di-tert-butyl peroxide is thermally cleaved by a hot filament (≈250 °C) and the resulting radicals collide with surface adsorbed monomers to initiate

• reducing R results in a reduced Γ. In order to develop process optimization strategies for deposition process having more than one gas phase reactant, it is important to determine which species has the Γ which controls the degree of conformality. Parlyene CVD During parylene CVD, the adsorption of a single

• coefficient of both initiator radicals is independent of filament temperature. Since the filament temperature determines the fraction of initiators cleaved to radicals, the sticking probability of the initiator radicals is independent of their gas phase concentration. This study confirms that volatile

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• ≈20 nm in diameter from the laser-deposited nanostructured material can be distinguished in the image. It is well known that gas phase species created by laser ablation of solids have a wide distribution of kinetic energy [17]. A considerable fraction of particles can have sufficient energy (≈100 eV

Thin SnO_x films for surface plasmon resonance enhanced ellipsometric gas sensing (SPREE)

• Daniel Fischer,
• Andreas Hertwig,
• Uwe Beck,
• Volkmar Lohse,
• Detlef Negendank,
• Martin Kormunda and
• Norbert Esser

Beilstein J. Nanotechnol. 2017, 8, 522–529, doi:10.3762/bjnano.8.56

• molecules on the surface and because the refracive index of the gas phase rises with the rising pressure. Results and Discussion Pressure dependence As described above, the gas experiments show a pressure dependence, which changes the Δ response. By changing the relative pressure inside the gas tube, a

• to the pressure which is in agreement with both explanations. Supposedly, a combination of both mechanisms occurs when the total pressure of the gas phase is changed. To achieve the linearity and sensitivity shown in the following gas measurement section, it is necessary to keep the pressure constant