Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• , University of Connecticut, Storrs, Connecticut 06269, USA 10.3762/bjnano.6.255 Abstract Blue and white light emission is observed when high voltage stress is applied using micrometer-separated tungsten probes across a nanoforest formed of ZnO nanorods. The optical spectrum of the emitted light consistently

• distribution of the emitted light, with pink–orange regions identifying percolation paths in some cases and high intensity blue and white light with center to edge variations in others, indicate that multiple mechanisms lead to light emission. Under certain conditions, the tungsten probe tips used to make

• electrical contact with the ZnO structures melt during the excitation, indicating that the local temperature can exceed 3422 °C, which is the melting temperature of tungsten. The distinct and narrow peaks in the optical spectra and the abrupt increase in current at high electric fields suggest that a plasma

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

• dehydrogenation as in the case of phenol. An electrochemically etched tungsten tip was used as an STM probe. The tips were repeatedly and gently touched to the Cu surface to coat them with copper, resulting in Cu-terminated tips for reliable switching [14]. We observed that sharp tips give high-contrast images

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

• Andrea Capasso,
• Theodoros Dikonimos,
• Francesca Sarto,
• Alessio Tamburrano,
• Giovanni De Bellis,
• Maria Sabrina Sarto,
• Giuliana Faggio,
• Angela Malara,
• Giacomo Messina and
• Nicola Lisi

Beilstein J. Nanotechnol. 2015, 6, 2028–2038, doi:10.3762/bjnano.6.206

• each sample and then averaged. Optical transmittance Transmittance spectra at normal incidence have been recorded in the 400–1100 nm wavelength range by a fiber optics spectrophotometer (HR4000CG-UV-NIR model by Ocean Optics), equipped with a tungsten halogen source and connected to the sample stage by

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

• a 0.5 mm tungsten wire and cleaned under ultra-high vacuum (UHV) conditions using voltage pulses of 10 ms duration between −10 and +10 V. The STM data were analysed with the WSxM freeware program [17]. The (111)-oriented Pt3Ti crystal was purchased from MaTeck (Jülich, Germany) and cleaned using

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

• Rachel M. Thorman,
• Ragesh Kumar T. P.,
• D. Howard Fairbrother and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2015, 6, 1904–1926, doi:10.3762/bjnano.6.194

• to previously performed gas phase and surface studies of four organometallic FEBID precursors: trimethyl(methylcyclopentadienyl)platinum(IV) (MeCpPtMe3) [15][20][21], tetrakis(trifluorophosphine)platinum(0) (Pt(PF3)4) [13][14][22][23], cobalt tricarbonyl nitrosyl (Co(CO)3NO) [10][24][25] and tungsten

• best fit to the cross section for methane desorption from MeCpPtMe3 physisorbed on a gold surface (Z = 79) and the calculated PE energy dependence of the SE yield from tungsten (Z =74). The comparison with tungsten is chosen as its atomic number, which strongly influences the PE energy dependence of

• . 4.3 Cobalt tricarbonyl nitrosyl; [Co(CO)3NO] and tungsten hexacarbonyl [W(CO)6] Cobalt tricarbonyl nitrosyl [Co(CO)3NO] was initially introduced in CVD as a liquid, easy-to-handle Co source. [76][77][78]. In CVD, Crawford et al. [78] reported an average composition of CoN0.5O0.9 with only traces of

A simple method for the determination of qPlus sensor spring constants

• John Melcher,
• Julian Stirling and
• Gordon A. Shaw

Beilstein J. Nanotechnol. 2015, 6, 1733–1742, doi:10.3762/bjnano.6.177

• is treated as a uniform cantilever the cross-section of which is rectangular with a triangular ridge (see Figure 1). The 50 μm tungsten wire tip is modeled as a rigid, slender rod extending from the center of the distal end of the beam with height H and axial offset B. Numerical values of the

• . Results are calculated for the 50 μm tungsten wire tip and a hypothetical massless tip. ψ is shown to have strong geometric dependence on H/L in Equation 4, a weak dependence on B/L, and a weak implicit dependence on the mass and rotational inertia of the tip. The governing PDE (Equation 3) can be reduced

• both a massless tip and a 50 μm tungsten wire tip with H = 400 μm. For the massless tip, the true spring constant is about 3% stiffer than the approximation. The addition of the tip mass actually shifts the true spring constant closer to the approximate value. For a 400 μm tip height, kz is only 1.5

Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

• Aleksandra Szkudlarek,
• Alfredo Rodrigues Vaz,
• Yucheng Zhang,
• Andrzej Rudkowski,
• Czesław Kapusta,
• Rolf Erni,
• Stanislav Moshkalev and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1508–1517, doi:10.3762/bjnano.6.156

• nanocrystals being dispersed inside and on top of the carbonaceous matrix. Experimental FEBID The experiments were performed using a Hitachi 3600 scanning electron microscope (SEM) with a tungsten filament. The precursors were filled into their reservoirs inside a glove box in argon or dry nitrogen atmosphere

Transformations of PTCDA structures on rutile TiO₂ induced by thermal annealing and intermolecular forces

• Szymon Godlewski,
• Jakub S. Prauzner-Bechcicki,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

• measurements, the sample was cooled to approximately 100 K using a flow cryostat, and the STM imaging was performed in a constant current mode at positive bias voltages (empty state imaging) with etched tungsten tips used as probes. For image processing and STM data analysis, WSxM software was used [42

Enhanced fullerene–Au(111) coupling in (2√3 × 2√3)R30° superstructures with intermolecular interactions

• Michael Paßens,
• Rainer Waser and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2015, 6, 1421–1431, doi:10.3762/bjnano.6.147

• commercial Createc STM (Germany) operated in ultra-high vacuum (UHV) with a base pressure of 1 × 10−10 mbar. All STM images were obtained in constant-current mode at 77 K sample temperature using a custom-made electrochemically etched tungsten tips. The dI/dV spectra were recorded through lock-in detection

Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• etched tungsten wire glued to one tine of the tuning fork were first prepared on clean Si(111)-(7 × 7) samples by standard STM techniques before imaging of the nanocrystal samples. During imaging of the supracrystal surface, spontaneous and regular tip changes were observed, thus it is possible that the

Closed-loop conductance scanning tunneling spectroscopy: demonstrating the equivalence to the open-loop alternative

• Chris Hellenthal,
• Kai Sotthewes,
• Martin H. Siekman,
• E. Stefan Kooij and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2015, 6, 1116–1124, doi:10.3762/bjnano.6.113

• functions below 1 eV for a tungsten–platinum system, which they ascribed to poor vacuum conditions and contamination [32]. Similarly, the presence of water layers in the tunneling junction can also lead to lower apparent barrier heights [35][38]. However, the measurements presented in this article have been

Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

• Jose Alberto Alvarado,
• Arturo Maldonado,
• Héctor Juarez,
• Mauricio Pacio and
• Rene Perez

Beilstein J. Nanotechnol. 2015, 6, 971–975, doi:10.3762/bjnano.6.100

• a tungsten boat. These powders are resistively heated and sublimated from the tungsten boat, placed 2 cm below and parallel to the substrate. The evaporation chamber has a pressure work of 4 × 10−4 Torr, and the current applied to the resistor is 42 A which resulted in a sufficiently high

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• custom-built quartz-tuning fork sensor was used for the measurements. It had a main resonance frequency of 51294 Hz, a quality factor above 1000 and an estimated stiffness of ≈3800 N·m−1 [22]. The contact to the tungsten tip was made of a thin golden wire in order to avoid crosstalk with the deflection

• signal from the tuning fork piezo [22][23]. The tip has been treated by annealing to 1200 °C in contact with a hot tungsten filament. The simultaneous current and frequency shift measurements were done in constant height mode. A very slow tunneling current feedback was applied for compensation of the

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• in a compact “BEETLE”-type setup [20]. The STM housing was filled with Argon gas in order to ensure an inert atmosphere. Tungsten tips were used for the STM measurements. The tips were prepared by chemical etching (2 M KOH solution) and then coated with hot glue to minimize the faradaic current

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• stirring by adding 1 g of the synthesized photocatalysts. A 500 W tungsten-halogen lamp was used as visible light source with a high pass UV light filter (FSQ-GG400, Newport Corp.). All experiments were carried out under identical conditions. The control experiment was carried out without photocatalyst to

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• subsequent annealing at 723 K for 10 min. All STM images were taken in constant-current mode with an electrochemically etched tungsten tip. The supramolecular networks based on Gd–ligand coordination motifs described in the manuscript were fabricated in a two-step process: The molecular linkers NC–C≡C–Ph3–C

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• an arc discharge method resulting in a 1–3 nm inner diameter and a length of 200 nm [20]. An arc discharge was generated between a hexagonal BN (h-BN)-filled tungsten rod as an anode and a cooled copper electrode as cathode. The dark gray BNNTs were collected from the surface of the copper cathode

Morphology, structural properties and reducibility of size-selected CeO_2−x nanoparticle films

• Maria Chiara Spadaro,
• Sergio D’Addato,
• Gabriele Gasperi,
• Francesco Benedetti,
• Paola Luches,
• Vincenzo Grillo,
• Giovanni Bertoni and
• Sergio Valeri

Beilstein J. Nanotechnol. 2015, 6, 60–67, doi:10.3762/bjnano.6.7

• treatments were performed under an oxygen partial pressure of pO2 = 1·10−7 mbar. XPS measurements were performed using an Al Kα X-ray source and a hemispherical electron analyzer. The STM was operated at room temperature in constant current mode, by using electrochemically etched tungsten tips, degassed by

Si/Ge intermixing during Ge Stranski–Krastanov growth

• Alain Portavoce,
• Khalid Hoummada,
• Antoine Ronda,
• Dominique Mangelinck and
• Isabelle Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246

• , the sample is loaded into a dual beam FIB. Here, an additional protective Pt layer is deposited by FIB (Figure 1a) and a wedge is cut (Figure 1b) and lifted off using an in situ tungsten finger (Figure 1c). Next, several pieces (approximately 3 × 3 µm2) of the sample wedge are glued onto preshaped Si

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• -light irradiation [50]. b) Volume of hydrogen generated (VH2) under visible-light irradiation from a tungsten halogen lamp using Janus and core-shell Au50nm@TiO2 nanostructures, as well as amorphous TiO2 and bare gold particles [50]. c) Schematic illustration of plasmonic dye-sensitized solar cells

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• conventional sol–gel methods. The preparation of sol–gel silicates have been reported by several research groups [71][72]. Nevertheless, the use of chitosan is not limited to silicates and titanates. El Kadib et al. [73] demonstrated the use of chitosan microspheres as templates for vanadium, tungsten, and

• molybdenum oxide clusters, which were shown to be active as catalysts for selective alcohol oxidation. Similarly, Ganesan and Gedanken [74] had prepared tungsten(VI) oxide nanoparticles through the encapsulation of ammonium metatungstate on chitosan and the subsequent calcination. These particles showed a

• higher catalytic activity than bulk tungsten trioxide. Other materials, such as cobalt-Prussian blue nanoparticles [75], Zn–Al layered double hydroxide [76], hydroxyapatite [77], and calcium carbonate [78], were also prepared within, or in the presence of, chitosan gels. In a biological approach, calcium

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• tungsten halogen lamp coupled with an Acton Reasearch Spectra Pro 300i monochromator. The photocurrent response as a function of the light intensity at given DC voltages and wavelengths were obtained by inserting neutral filters of various optical density on the light path towards the sample. A calibrated

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• hMSC in the presence of silver nanoparticles, the cells were sputtered with gold and subsequently with a tungsten layer to protect the cut surface from gallium contamination. Then the cross-sectional cutting area was analyzed by scanning electron microscopy (SEM). In different areas of silver

• concentration of silver nanoparticles (20 µg mL−1) for 24 h and single monocytes or lymphocytes were crosscut with FIB for intracellular imaging. Before FIB analysis, the cells were additionally coated with a thin layer of tungsten to protect the cut area from ion contamination. Similar to the results of light

Imaging the intracellular degradation of biodegradable polymer nanoparticles

• Anne-Kathrin Barthel,
• Martin Dass,
• Melanie Dröge,
• Jens-Michael Cramer,
• Daniela Baumann,
• Markus Urban,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2014, 5, 1905–1917, doi:10.3762/bjnano.5.201

• achieved and applied on a copper grid (3.05, 300 mesh, Agar Scientific, U.K.). The sections were observed in a Zeiss EM 912 transmission electron microscope with a tungsten filament at an acceleration voltage of 120 kV. Micrographs were taken via a Cantega Olympus slow scan CCD camera. UV−visible (UV−vis

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• obtained in dispersive plane operation, in which the exit plane of the energy analyzer is projected onto the detector. b) The (00) LEED spot profile from W(110). Tungsten 4f7/2 core level spectrum from a clean W(110) surface acquired in dispersive plane mode. The photon energy is 90 eV. The acquisition