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Search for "tungsten" in Full Text gives 184 result(s) in Beilstein Journal of Nanotechnology.

Change of the work function of platinum electrodes induced by halide adsorption

  • Florian Gossenberger,
  • Tanglaw Roman,
  • Katrin Forster-Tonigold and
  • Axel Groß

Beilstein J. Nanotechnol. 2014, 5, 152–161, doi:10.3762/bjnano.5.15

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  • chlorine, bromine and iodine on Pt(111) leads to an unexpected decrease of the work function. Based on calculations for several adsorbates on tungsten surfaces, Leung, Kao and Su pointed out that it is possible to relate the electronegativity scale to the direction of the charge transfer but not
  • nitrogen adsorbed on a tungsten (100) surface. They showed that the decrease of the work function depends strongly on the length of the chemisorption bond. If the adatom is located close to the surface, it is in the region of the overspill electron density of the metal. This leads to an area of electron
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Published 10 Feb 2014

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

  • Boris Polyakov,
  • Sergei Vlassov,
  • Leonid M. Dorogin,
  • Jelena Butikova,
  • Mikk Antsov,
  • Sven Oras,
  • Rünno Lõhmus and
  • Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

Graphical Abstract
  • ) equipped with a custom-made force sensor. The force sensor was made by gluing an electrochemically sharpened tungsten wire or commercial AFM cantilever with a sharp tip (Nanosensor ATEC-CONT cantilevers C = 0.2 N/m) to one prong of a commercially available quartz tuning fork (QTF). The tip of ATEC-CONT
  • NPs (a), frozen droplet for Ag NPs solidified on a substrate (b), DMT-M model for Ag NPs solidified without contact to a substrate (c). SEM snapshots of the manipulation process of a Au NP by using a tungsten tip, and the corresponding force curve. The black solid arrow in image (a) indicates the
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Published 05 Feb 2014

STM tip-assisted engineering of molecular nanostructures: PTCDA islands on Ge(001):H surfaces

  • Amir A. Ahmad Zebari,
  • Marek Kolmer and
  • Jakub S. Prauzner-Bechcicki

Beilstein J. Nanotechnol. 2013, 4, 927–932, doi:10.3762/bjnano.4.104

Graphical Abstract
  • were carried out in constant current mode at room temperature (rt) by means of electrochemically etched tungsten tips as probes. Scanning tunneling spectroscopy (STS) measurements were carried out at rt. The STS data were averaged over 2500 curves taken from a grid covering a 10 × 10 nm2 surface area
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Published 18 Dec 2013

In situ growth optimization in focused electron-beam induced deposition

  • Paul M. Weirich,
  • Marcel Winhold,
  • Christian H. Schwalb and
  • Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

Graphical Abstract
  • ; nanotechnology; tungsten; Introduction In focused electron-beam-induced deposition, FEBID in short, a (metal-)organic or inorganic volatile precursor gas, which was previously adsorbed on a substrate surface, is dissociated in the focus of an electron beam provided by a scanning (SEM) or transmission electron
  • % [16]. Changes of the precursor flux and the partial pressure of water in the residual gas also influence the final composition and increases the extend of tungsten oxidation in the deposit [15]. With regard to the electrical conductivity of the deposits, a key quantity in many applications of FEBID
  • in a Pt/C ratio that is largely independent from the deposition parameter. Furthermore, in contrast to tungsten, platinum is not susceptible to oxidation or carbide formation, which results in a nano-granular rather than amorphous microstructure. Experimental The FEBID process takes place in a dual
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Published 17 Dec 2013

Simulation of electron transport during electron-beam-induced deposition of nanostructures

  • Francesc Salvat-Pujol,
  • Harald O. Jeschke and
  • Roser Valentí

Beilstein J. Nanotechnol. 2013, 4, 781–792, doi:10.3762/bjnano.4.89

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  • -induced growth of tungsten nanostructures on SiO2 substrates by using a Monte Carlo simulation of the electron transport. This study gives a quantitative insight into the deposition of energy and charge in the substrate and in the already existing metallic nanostructures in the presence of the electron
  • simulation scheme, and we restrict our considerations to the interaction of the primary electrons with the substrate and the nanostructure at different stages of its growth. The precursor gas we consider throughout this study is tungsten hexacarbonyl, W(CO)6, and the corresponding deposits WxCyOz, i.e
  • ., amorphous tungsten oxycarbides with varying carbon and oxygen contents. W(CO)6 belongs to the class of organometallic compounds that are well established for the EBID process [14][15][16]. It has been studied in detail by mass spectrometry [17][18][19] and photoelectron or photoionization spectroscopy [20
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Published 22 Nov 2013

Influence of particle size and fluorination ratio of CFx precursor compounds on the electrochemical performance of C–FeF2 nanocomposites for reversible lithium storage

  • Ben Breitung,
  • M. Anji Reddy,
  • Venkata Sai Kiran Chakravadhanula,
  • Michael Engel,
  • Christian Kübel,
  • Annie K. Powell,
  • Horst Hahn and
  • Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 705–713, doi:10.3762/bjnano.4.80

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  • precursor was performed in a sealed tungsten carbide vial under inert conditions. The CFx powder was ball-milled for 2 h, with a ball to powder ratio of 24:1 and milling speeds of 200, 300, and 400 rpm. To adjust the active material to carbon ratio in the products, different graphite fluoride samples were
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Published 01 Nov 2013

The role of electron-stimulated desorption in focused electron beam induced deposition

  • Willem F. van Dorp,
  • Thomas W. Hansen,
  • Jakob B. Wagner and
  • Jeff T. M. De Hosson

Beilstein J. Nanotechnol. 2013, 4, 474–480, doi:10.3762/bjnano.4.56

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  • desorption. Keywords: desorption energy; focused electron beam induced processing; scanning transmission electron microscopy; temperature dependence; tungsten hexacarbonyl; Introduction When the electron beam in an electron microscope is focused on a sample in the presence of a precursor gas, it can be
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Published 14 Aug 2013

Structural and thermoelectric properties of TMGa3 (TM = Fe, Co) thin films

  • Sebastian Schnurr,
  • Ulf Wiedwald,
  • Paul Ziemann,
  • Valeriy Y. Verchenko and
  • Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 461–466, doi:10.3762/bjnano.4.54

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  • powder. For that purpose, a rotating tube (inner diameter 3.5 mm) with an internal thread transports the powder towards its end, where the powder falls grain-by-grain onto an electrically heated tungsten boat and evaporates. Each grain (typical diameter 10 μm) contributes significantly less than a
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Published 31 Jul 2013

Optimal geometry for a quartz multipurpose SPM sensor

  • Julian Stirling

Beilstein J. Nanotechnol. 2013, 4, 370–376, doi:10.3762/bjnano.4.43

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  • excited at or near one of its eigenfrequencies, properties such as the Q factor, eigenfrequencies, effective spring constant [1] and other geometrical properties [2] of the eigenmodes become important. AFM and LFM sensors have evolved from gold foil with diamond tip [3] and bent tungsten wires [4
  • spring constants, we propose a new sensor geometry. The proposed design, see Figure 1, is to attach a tungsten tip to the centre of a quartz beam. The design exploits the intrinsic symmetry of the sensor to remove any unwanted lateral motion in the principal eigenmode (Figure 1b), thus allowing for
  • measurements in the LFM mode. We consider a maximum tip length of 1.73 mm, i.e., the length that would give klat = 500 N·m−1; thus, to keep the spring constant of the tip above 10 kN·m−1 the diameter of the tungsten wire must be greater than 144 μm. We will consider a tip diameter, Dtip, of 150 μm, an easily
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Published 17 Jun 2013

High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

  • John Melcher,
  • David Martínez-Martín,
  • Miriam Jaafar,
  • Julio Gómez-Herrero and
  • Arvind Raman

Beilstein J. Nanotechnol. 2013, 4, 153–163, doi:10.3762/bjnano.4.15

Graphical Abstract
  • relatively high bandwidth in vacuum by using nonstandard probes. Kawai and Kawakatsu [52] exploited a higher eigenmode of a silicon cantilever that had an unperturbed resonance frequency of 1.8 MHz. Erlandsson et al. [51] used a tungsten wire with an unperturbed quality factor of just 550 in vacuum. The
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Published 27 Feb 2013

Low-dose patterning of platinum nanoclusters on carbon nanotubes by focused-electron-beam-induced deposition as studied by TEM

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

Beilstein J. Nanotechnol. 2013, 4, 77–86, doi:10.3762/bjnano.4.9

Graphical Abstract
  • ], tungsten [19][20] and cobalt [21][22] nanostructures has been reported. A recent study has demonstrated the successful formation of binary Si–Pt nanostructures by FEBID [23]. Ultrasmall well-dispersed nanoclusters supported on CNTs are of most interest as the (electro-) catalytic activity can be increased
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Published 04 Feb 2013

Calculation of the effect of tip geometry on noncontact atomic force microscopy using a qPlus sensor

  • Julian Stirling and
  • Gordon A. Shaw

Beilstein J. Nanotechnol. 2013, 4, 10–19, doi:10.3762/bjnano.4.2

Graphical Abstract
  • , provided the tip geometry is well defined, and the static spring constant is known. The tine of a qPlus sensor was modeled as a quartz beam of length L = 2.4 mm, width w = 130 μm, and thickness tTF = 214 µm (Figure 1a). The tip was modeled as a tungsten cylinder of diameter Dtip attached to the end of the
  • ° mirror positioned near the qPlus sensor allowed lateral deflection measurements of the tip to be made without remounting the sensor or interrupting the excitation, thus limiting changes to the transfer function. Tungsten wire of 50 μm in diameter was attached to the end of the bare qPlus sensor with EPO
  • control over the quantity of material removed from the tip [18]. The sensor was positioned with a micromanipulator such that the 1 M KOH electrolyte contacted only the tungsten probe tip, then a potential of 0.3 V versus SCE was applied until the desired charge was accumulated from the Faradaic etch
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Published 08 Jan 2013

Characterization of the mechanical properties of qPlus sensors

  • Jan Berger,
  • Martin Švec,
  • Martin Müller,
  • Martin Ledinský,
  • Antonín Fejfar,
  • Pavel Jelínek and
  • Zsolt Majzik

Beilstein J. Nanotechnol. 2013, 4, 1–9, doi:10.3762/bjnano.4.1

Graphical Abstract
  • . This method is based on gluing small pieces of a tungsten wire; the mass is obtained from the volume of the wire, which is measured by optical microscopy. To facilitate detection of oscillation eigenfrequencies under ambient conditions, we designed and built a device for testing qPlus sensors
  • before and, as the last step during the sensor construction, the tip is carefully mounted directly to the gold wire by a conductive epoxy (EPO-TEK H21D) in such a way that there is no additional electrical connection to the rest of the prong. Tips are etched from 0.125 μm tungsten wire in 2 M solution of
  • this method, we fix a small piece of tungsten wire as close as possible to the tip. The mass of the load was estimated from its dimensions measured with the optical microscope and afterwards calculated using the bulk density of tungsten ρ = 19.3 g/cm3. The amount of added mass must be chosen carefully
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Published 02 Jan 2013

Diamond nanophotonics

  • Katja Beha,
  • Helmut Fedder,
  • Marco Wolfer,
  • Merle C. Becker,
  • Petr Siyushev,
  • Mohammad Jamali,
  • Anton Batalov,
  • Christopher Hinz,
  • Jakob Hees,
  • Lutz Kirste,
  • Harald Obloh,
  • Etienne Gheeraert,
  • Boris Naydenov,
  • Ingmar Jakobi,
  • Florian Dolde,
  • Sébastien Pezzagna,
  • Daniel Twittchen,
  • Matthew Markham,
  • Daniel Dregely,
  • Harald Giessen,
  • Jan Meijer,
  • Fedor Jelezko,
  • Christoph E. Nebel,
  • Rudolf Bratschitsch,
  • Alfred Leitenstorfer and
  • Jörg Wrachtrup

Beilstein J. Nanotechnol. 2012, 3, 895–908, doi:10.3762/bjnano.3.100

Graphical Abstract
  • incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon–vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition. Keywords: CVD diamond doping
  • MWPECVD. Emphasis was placed on a reproducible dopant addition to the growth process aiming at a targeted in situ incorporation of color centers based on nickel and tungsten impurities. A very promising single-photon-emitting defect for quantum-cryptographic applications is the so-called NE8-center [17
  • already conducted to produce this center [21][22]. However, the yield of nickel–nitrogen-related centers seems to be rather low. Tungsten is known to produce a family of so-called W5-centers with several luminescence lines near 714 nm [23]. Up to now these centers were only produced by chance in
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Published 21 Dec 2012

Pinch-off mechanism in double-lateral-gate junctionless transistors fabricated by scanning probe microscope based lithography

  • Farhad Larki,
  • Arash Dehzangi,
  • Alam Abedini,
  • Ahmad Makarimi Abdullah,
  • Elias Saion,
  • Sabar D. Hutagalung,
  • Mohd N. Hamidon and
  • Jumiah Hassan

Beilstein J. Nanotechnol. 2012, 3, 817–823, doi:10.3762/bjnano.3.91

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  • is considered to be in the center at the bottom of the channel with the BOX interface. According to the material of the tip used in the experimental measurements (Tungsten), the work function of the contacts is taken to be 5.12 eV in all simulation steps. The simulations were carried out by using the
  • should be noted that the measurement setup has four highly accurate source/monitor units (SMUs) and is designed for Kelvin connections. Four lakeshore Tungsten tips with 3 µm radius were used with the SMUs to measure the electrical characteristics of the device. An overall good agreement is found between
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Published 03 Dec 2012

Spring constant of a tuning-fork sensor for dynamic force microscopy

  • Dennis van Vörden,
  • Manfred Lange,
  • Merlin Schmuck,
  • Nico Schmidt and
  • Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

Graphical Abstract
  • evaluation of the spring constant was performed for a TF with a tip (e.g., a 25–100 μm tungsten wire) attached to the front face of the free prong of the tuning fork. It is connected separately through a metallic wire (e.g., a 25 μm gold wire) to collect the tunneling current, avoiding crosstalk with the
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Published 29 Nov 2012

Plasmonics-based detection of H2 and CO: discrimination between reducing gases facilitated by material control

  • Gnanaprakash Dharmalingam,
  • Nicholas A. Joy,
  • Benjamin Grisafe and
  • Michael A. Carpenter

Beilstein J. Nanotechnol. 2012, 3, 712–721, doi:10.3762/bjnano.3.81

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  • . The co-sputtered film was shown to have 9 atom % Au. Optical sensing apparatus The sensing apparatus used for the experiments is shown in Figure 9. The setup consists of, from right to left, an Ocean Optics tungsten halogen source with an emission wavelength range of 360–2500 nm; the quartz flow cell
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Published 31 Oct 2012

Paper modified with ZnO nanorods – antimicrobial studies

  • Mayuree Jaisai,
  • Sunandan Baruah and
  • Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

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  • conditions, i.e., in the dark, under light from a fluorescent lamp (1 klx), or under light from a tungsten–halogen lamp (1.2 klx). The intensity of light was kept comparable to standard room lighting conditions. Increase in zone of inhibition for E. coli and S. aureus with increasing incubation time under
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Published 11 Oct 2012

Spontaneous dissociation of Co2(CO)8 and autocatalytic growth of Co on SiO2: A combined experimental and theoretical investigation

  • Kaliappan Muthukumar,
  • Harald O. Jeschke,
  • Roser Valentí,
  • Evgeniya Begun,
  • Johannes Schwenk,
  • Fabrizio Porrati and
  • Michael Huth

Beilstein J. Nanotechnol. 2012, 3, 546–555, doi:10.3762/bjnano.3.63

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  • bridging and terminal ligands are oriented towards the surface (Figure 7a), with distances to the surface of 2.08–2.39 Å. The obtained distances agree well with the recently reported hydrogen-bonding distance of tungsten carbonyls with the SiO2 substrate [33]. This configuration turns out to be the most
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Published 25 Jul 2012

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

  • Gregor Hlawacek,
  • Vasilisa Veligura,
  • Stefan Lorbek,
  • Tijs F. Mocking,
  • Antony George,
  • Raoul van Gastel,
  • Harold J. W. Zandvliet and
  • Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

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  • the formation of cobalt nanoclusters, an atomically clean Ge{001} substrate was obtained by prolonged 800 eV Ar+ ion sputtering followed by annealing of the sample through resistive heating at 1100 K. Several monolayers of Co were evaporated by resistively heating a tungsten wire wrapped with a pure
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Published 12 Jul 2012

Models of the interaction of metal tips with insulating surfaces

  • Thomas Trevethan,
  • Matthew Watkins and
  • Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

Graphical Abstract
  • atomic resolution. Chromium and tungsten tips are used to image the NaCl(001) and MgO(001) surfaces. The interaction of the tips with the surface is simulated by using density-functional-theory calculations employing a mixed Gaussian and plane-wave basis and cluster-tip models. In each case, the apex of
  • chromium and tungsten, which are chosen due to their common use in scanning-probe experiments. For several different combinations of tip and surface, we determine the tip–surface force field and the origin of the tip–surface interaction at close approach. These calculations employ cluster-tip models and
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Published 13 Apr 2012

Junction formation of Cu3BiS3 investigated by Kelvin probe force microscopy and surface photovoltage measurements

  • Fredy Mesa,
  • William Chamorro,
  • William Vallejo,
  • Robert Baier,
  • Thomas Dittrich,
  • Alexander Grimm,
  • Martha C. Lux-Steiner and
  • Sascha Sadewasser

Beilstein J. Nanotechnol. 2012, 3, 277–284, doi:10.3762/bjnano.3.31

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  • metallic precursors evaporated from a tungsten boat for Zn and a tantalum effusion cell for sulfur. The substrate was heated to ~250 °C. A thickness monitor (Maxtec TM-400) with a quartz-crystal sensor was used to measure the deposition rate of Zn. The thickness of the films was ~120 nm, as measured with a
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Published 23 Mar 2012

A measurement of the hysteresis loop in force-spectroscopy curves using a tuning-fork atomic force microscope

  • Manfred Lange,
  • Dennis van Vörden and
  • Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 207–212, doi:10.3762/bjnano.3.23

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  • . This means that for a given tunneling current the attractive forces are stronger on the Ag/Si(111) √3 × √3 surface than on the PTCDA islands. Prior to the force-spectroscopy measurements the tungsten tip was prepared by making “soft contact” between the tip and a PTCDA island. Before and after the soft
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Published 08 Mar 2012

Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

  • Adam Sweetman,
  • Sam Jarvis,
  • Rosanna Danza and
  • Philip Moriarty

Beilstein J. Nanotechnol. 2012, 3, 25–32, doi:10.3762/bjnano.3.3

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  • 1200 °C, and then slow cooling from 900 °C to room temperature before being placed into the scan head. We introduced commercial qPlus sensors (Omicron GmbH), with an electrochemically etched tungsten wire attached to one tine of the tuning fork, into the scan head without any ex situ tip treatment. The
  • silicon- rather than tungsten-terminated, and this assumption is supported by a combined scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX) study on an STM tip prepared by similar methods. We imaged at constant Δf, maintaining a constant oscillation amplitude (A0). All data
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Published 09 Jan 2012

Generation and agglomeration behaviour of size-selected sub-nm iron clusters as catalysts for the growth of carbon nanotubes

  • Ravi Joshi,
  • Benjamin Waldschmidt,
  • Jörg Engstler,
  • Rolf Schäfer and
  • Jörg J. Schneider

Beilstein J. Nanotechnol. 2011, 2, 734–739, doi:10.3762/bjnano.2.80

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  • either thermal evaporation (heating Al in a boron nitride crucible with a tungsten filament) or electron beam evaporation onto a commercial TEM grid (SiOx; Fa. Plano, Wetzlar). Aluminium buffer layer (10 nm) deposition was monitored by means of a quartz crystal microbalance (Cressington MTM 10). After
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Published 01 Nov 2011
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