Changes of the absorption cross section of Si nanocrystals with temperature and distance

• Michael Greben,
• Petro Khoroshyy,
• Sebastian Gutsch,
• Daniel Hiller,
• Margit Zacharias and
• Jan Valenta

Beilstein J. Nanotechnol. 2017, 8, 2315–2323, doi:10.3762/bjnano.8.231

• of the samples see our recent paper [11]. The PL experiments were performed under excitation with a 405 nm diode laser the beam of which was modulated using a quartz acousto-optic cell. The edge switching time is about 100 ns. The laser is coupled to a custom-made micro-spectroscopy set-up with an

High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

• Alfredo J. Diaz,
• Hanaul Noh,
• Tobias Meier and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 2069–2082, doi:10.3762/bjnano.8.207

• sensing humidity [21] and for temperature-dependent switching of electrochemical behavior using nanoclay substitutes [22]. Recently, nacre-mimetic electrically conductive nanocomposites have been reported, one of which exhibited good electrical conductivity and excellent mechanical properties [23] and the

Fabrication of carbon nanospheres by the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) core–shell composite nanoparticles

• Dafu Wei,
• Youwei Zhang and
• Jinping Fu

Beilstein J. Nanotechnol. 2017, 8, 1897–1908, doi:10.3762/bjnano.8.190

• , which are close to those of the DLS results (Supporting Information File 1, Table S3). The core–shell structure of the PAN–PMMA nanoparticles was also revealed by switching the dispersion medium from water to 50% NaSCN aqueous solution, a selective solvent for PAN. Figure 4d shows the TEM image of the

• dispersion of PAN-PMMA1 nanoparticles in 50% NaSCN aqueous solution. It can be seen that the PAN-PMMA1 nanoparticles displayed a typical core–shell morphology with dark cores and white shells. After switching the dispersion medium from water to 50% NaSCN aqueous solution, more and more Na+ and SCN− ions

Carbon nano-onions as fluorescent on/off modulated nanoprobes for diagnostics

• Stefania Lettieri,
• Marta d’Amora,
• Adalberto Camisasca,
• Alberto Diaspro and
• Silvia Giordani

Beilstein J. Nanotechnol. 2017, 8, 1878–1888, doi:10.3762/bjnano.8.188

• boron dipyrromethene (BODIPY) dye with on/off modulated fluorescence emission activated by an acidic environment. The switching properties are linked to the photoinduced electron transfer (PET) characteristics of the dimethylamino functionalities attached to the BODIPY core. The on/off emission of the

• biocompatibility [20]. We have previously shown that the pH-dependent switching ability of a dye is preserved when attached to CNOs [21] and on single-wall carbon nanotubes, [22] both in solution and in vitro. Thus, CNOs are suitable nanomaterials for biosensing applications. We exploited the photoinduced electron

• development of a nanosensor which can be “turned on” in an acidic environment. Remarkably, the fluo-CNOs maintained the switching properties upon cell internalization, as they were “switched-on” in response to acidic pH. In vitro experiments on HeLa cells showed excellent cellular uptake and low toxicity of

Process-specific mechanisms of vertically oriented graphene growth in plasmas

• Subrata Ghosh,
• Shyamal R. Polaki,
• Niranjan Kumar,
• Sankarakumar Amirthapandian,
• Mohamed Kamruddin and
• Kostya (Ken) Ostrikov

Beilstein J. Nanotechnol. 2017, 8, 1658–1670, doi:10.3762/bjnano.8.166

• growth temperature by just switching off the microwave plasma. Finally, the substrates were allowed to cool down to room temperature and samples were taken out from the vacuum chamber for further characterization. Characterization of VGNs Morphological features of these films were examined by field

Light-induced magnetoresistance in solution-processed planar hybrid devices measured under ambient conditions

• Sreetama Banerjee,
• Daniel Bülz,
• Danny Reuter,
• Karla Hiller,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2017, 8, 1502–1507, doi:10.3762/bjnano.8.150

• already shown for thermally evaporated films by Saragi et al. [9]. In order to investigate the influence of the electrode distance on the OMAR magnitude and on the timeline of the OMAR response to the switching of magnetic field, we used two planar device geometries: i) commercially available micro

• when comparing two device architectures with significantly different volume of the active organic channel. The photocurrent of the HED-TIE devices is a factor of two higher and the photo-switching occurs to be faster in the HED-TIE devices, due to the smaller electrode gap. Figure 2c and Figure 2d show

• the magnetoconductance response of the same devices. Here, the device current over time was measured by switching on and off a constant applied magnetic field while the illumination was kept on throughout the measurements. Both OFETs and the HED-TIE devices were found to exhibit positive

Synthesis of [Fe(L_eq)(L_ax)]_n coordination polymer nanoparticles using blockcopolymer micelles

• Christoph Göbel,
• Ottokar Klimm,
• Florian Puchtler,
• Sabine Rosenfeldt,
• Stephan Förster and
• Birgit Weber

Beilstein J. Nanotechnol. 2017, 8, 1318–1327, doi:10.3762/bjnano.8.133

• nanomaterials with SCO properties comparable to those of the bulk material is still in its infancy [19][20][21][22][23]. SCO materials can be switched by external stimuli such as temperature, pressure or light between a high spin (HS) and a low spin (LS) state [5][18]. Switching between these two states alters

Adsorption characteristics of Er₃N@C₈₀on W(110) and Au(111) studied via scanning tunneling microscopy and spectroscopy

• Sebastian Schimmel,
• Zhixiang Sun,
• Danny Baumann,
• Denis Krylov,
• Nataliya Samoylova,
• Alexey Popov,
• Bernd Büchner and
• Christian Hess

Beilstein J. Nanotechnol. 2017, 8, 1127–1134, doi:10.3762/bjnano.8.114

• center [4]. Dependent on the cluster composition and due to the intercalation inside a protecting carbon cage, intriguing properties emerge. For instance, single molecular magnetism was observed for DySc2N@C80 [5] and conductance switching by tunneling current induced cluster rotations between chiral

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

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

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• actuation strain 56% higher than pristine graphene paper [158]. In another work, Liang et al. have prepared free-standing graphene–Fe3O4 hybrid papers having magnetic-controlled switching performance [159]. One interesting structure was realised using hydrothermal reduction by Wu et al. They prepared Fe

• + acts as a bridge, connecting GO sheets and introducing new energy levels along the electron transport pathway thereby opening up possible conduction channels [216]. Singh et al. reported a bipolar, resistive switching device incorporating a copper oxide and multilayer graphene hybrid where the

• electrical characteristics of CuO–graphene bilayer structure has been modified largely due to the electronic interaction at the hybrid interface. The O2 intake capacity of the multilayer graphene results in reversible bipolar resistive switching properties [217]. Zhou et al. prepared graphene-wrapped CuO

Copper atomic-scale transistors

• Fangqing Xie,
• Maryna N. Kavalenka,
• Moritz Röger,
• Daniel Albrecht,
• Hendrik Hölscher,
• Jürgen Leuthold and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2017, 8, 530–538, doi:10.3762/bjnano.8.57

• -scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of

• the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (Ubias

• ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

• probe along with on-chip electrical wiring. Upon switching the electrical signal on and off, we observe a fast initial response on a sub-nanosecond timescale, followed by an additional slower response on the scale of 10–100 ns. A similar behavior has been observed with electrically biased SWCNT films

• measurements using single-photon detectors with different time resolutions given by the timing jitter of the detectors (350 ps for τ-SPAD and 40 ps for SNSPD for a wavelength range of 700–900 nm). Upon switching off the electrical signal, the emission intensity decays exponentially. Experimentally, τtherm

• generator and connectors lead to additional broadening of the light pulse and thus increase of the measured decay time. Due to these instrumental restrictions, we are not able to determine the upper limit of the switching rate for the presented waveguide-coupled CNT-based light emitter. However, even the

Grazing-incidence optical magnetic recording with super-resolution

• Gunther Scheunert,
• Sidney. R. Cohen,
• René Kullock,
• Ryan McCarron,
• Katya Rechev,
• Ifat Kaplan-Ashiri,
• Ora Bitton,
• Paul Dawson,
• Bert Hecht and
• Dan Oron

Beilstein J. Nanotechnol. 2017, 8, 28–37, doi:10.3762/bjnano.8.4

• may open an alternative route to high-durability HAMR. Magnetic switching is demonstrated on consumer-grade CoCrPt perpendicular magnetic recording media using a green and a near-infrared diode laser. Sub-500 nm magnetic features are written in the absence of a NFT in a moderate bias field of only μ0H

• (featuring PMR CoCrPt recording medium, TC ≈ 880 K) we demonstrate, by proper choice of parameters, that even laser powers comparable to SPR-HAMR already cause magnetic switching in the presence of a homogeneous magnetic bias field of μ0HB = 0.3 T – at a resolution six times smaller than the laser spot size

• -incidence laser-sample geometry were Guyader and co-workers [13] who studied sub-100 ps all-optical magnetization switching of patterned ferrimagnetic GeFeCo recording material – also in an effort to elude the far-field diffraction limit, but utilizing lateral electric field interference patterns. In

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

• of particle incidence. Moreover, two-fold alignment domains can appear with two easy axes symmetrical with respect to that plane [4][8]. Amosova et al. [5] explained switching in LC alignment in terms of the length of the crystallites forming relief of the aligning surface and surface wetting by

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

• Christoph Schreyvogel,
• Vladimir Polyakov,
• Sina Burk,
• Helmut Fedder,
• Andrej Denisenko,
• Felipe Fávaro de Oliveira,
• Ralf Wunderlich,
• Jan Meijer,
• Verena Zuerbig,
• Jörg Wrachtrup and
• Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

• terminated diamond surface. By changing the applied potential on the Schottky contact, we are able to actively switch single NV centres between all three charge states NV+, NV0 and NV− on a timescale of 10 to 100 ns, corresponding to a switching frequency of 10–100 MHz. This switching frequency is much

• higher than the hyperfine interaction frequency between an electron spin (of NV−) and a nuclear spin (of 15N or 13C for example) of 2.66 kHz. This high-frequency charge state switching with a planar diode structure would open the door for many quantum optical applications such as a quantum computer with

• for quantum communication and cryptography. Keywords: active charge state control; diamond; fast charge state switching; NV centre; two-dimensional Schottky diode; Introduction The nitrogen-vacancy centre (NV centre) in diamond is known to exist in at least three different charge states (NV−, NV0

Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• SnO2 leads to a considerable increase in selectivity as well as increase in sensitivity to CO(CH3)2, which is according to literature [2], completely unique for both TiO2 and SnO2. Secondly, the well thought out, design engineering of the TiO2 microstructure allows for switching from the H2 highly

Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

• Austin Deschenes,
• Sadid Muneer,
• Mustafa Akbulut,
• Ali Gokirmak and
• Helena Silva

Beilstein J. Nanotechnol. 2016, 7, 1676–1683, doi:10.3762/bjnano.7.160

• lower potential side of the magnetic junction. This asymmetry in heating, which has also been observed experimentally, is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset

• deposition SiO2 [2][17] and Si3N4 [18]. The “ON” and “OFF” states of the device are represented via interchangeable sets of materials properties for the CoFeB layers [4][13] (Figure 2, Figure 3) that are chosen based on the desired switching operation to be simulated (anti-parallel properties to simulate an

• OFF–ON switching operation, parallel properties for the converse operation, see inset in Figure 2). Simulation procedures Analysis of the self-heating of the device is performed for different passivation materials (Table 1), positive and negative current polarity, and four contact configurations

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• is demonstrated by the investigation of real water samples. For all real water samples higher signal changes were achieved when the nanohole arrays were functionalized with graphene shown exemplary with water from the river Danube (Figure 7A). By switching back to washing conditions, the original

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• are about 0.5 µs and 5.5 µs, respectively. Rise time and fall time were estimated from characteristics taking into consideration only the interval between 10% and 90% of the signal peak value. For all switching frequency values, the response of the tested photodetector structures is fast and shows a

• ; (b) the relative balance (Vmax − Vmin)/Vmax versus switching frequency. The inset represents the schematic setup used to investigate the time response of the photodetector. Acknowledgements This work was supported by the Romanian National Authority for Scientific Research through the Core Program

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• switching; photonic crystal; plasmonic nanoparticles; Introduction Structural colour is colour due to the Bragg reflection (in photonic structures for example) as opposed to colour from pigments or colour centres [1]. The active tuning of the structural colour in photonic crystals is a subject that has

Adiabatic superconducting cells for ultra-low-power artificial neural networks

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev and
• Maxim V. Tereshonok

Beilstein J. Nanotechnol. 2016, 7, 1397–1403, doi:10.3762/bjnano.7.130

• ], those for signal classification and recognition are less developed. A solution for the recognition problem by employing perceptron ANNs was sought in earlier works with SQUID-based neuron switching [14][15] in the resistive state. In subsequent variations [16][17], this feature was found to drastically

Customized MFM probes with high lateral resolution

• Óscar Iglesias-Freire,
• Miriam Jaafar,
• Eider Berganza and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2016, 7, 1068–1074, doi:10.3762/bjnano.7.100

• the external field and extract the intrinsic hysteresis loop of the MFM tip [25]. Typically, a large Barkhausen jump is observed with a well-defined switching field. By doing so, the measured average switching field for the 20 nm Co homemade tip is μ0∙ = (31 ± 4) mT, where a total of 30

Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

• Anja Henning-Knechtel,
• Matthew Wiens,
• Mathias Lakatos,
• Andreas Heerwig,
• Frieder Ostermaier,
• Nora Haufe and
• Michael Mertig

Beilstein J. Nanotechnol. 2016, 7, 948–956, doi:10.3762/bjnano.7.87

• origami chains may occur around the field intensity maxima. Switching the field off resulted in diffusing of the structures away from the electrodes, and thus, disassembling of the chains (Figure 4d). On the one hand, this is a clear sign that the gold nanoparticle-conjugated DNA origami do not

• irreversibly aggregate during DEP deposition, as it was observed for the formation of conducting wires by DEP deposition of plain, unsupported gold nanoparticles [35][36][37][38][39]. On the other hand, the disassembly of our chain structures upon switching off the electrical field prohibits any further high

• at 1·106 V/m and 16 MHz. Inverted fluorescence microscopy image after 16 min (left) and 26 min (right) ac field application. (d) Inverted fluorescence microscopy images of the trapping behavior during on/off-switching of the ac field. Electrical field intensity (a) in the presence of a gold

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

• for the possibility of tuning the LC properties by doping with SWCNTs. In the last years, several studies have described SWCNT orientation in LC matrices, based on for example the conductivity of SWCNT-doped LC cells at different switching degrees [12][13][14][15]. SWCNT–LC blends co-align

• switching of the CNTs caused by the interaction with the field and with the LC molecules in this study. Therefore, this study is focused on determining the origin of the SWCNT switching in a LC matrix, by isolating the LC switching and the SWCNT switching, and by studying both individual SWCNTs in a

• negative LC matrix and the macroscopic impedance of a liquid crystal cell filled with negative LC doped with SWCNTs. In order to separate the field induced switching of the LC and the SWCNTs, a cells with homogenously aligned LC of negative dielectric anisotropy is employed. The SWCNT switching pattern in

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• changed from constant velocity to constant surface pressure: A threshold-value of Π = 0.5 mN/m was used for switching from fast compression to constant surface pressure. When the pressure dropped below the threshold-value, the control unit compressed the film until the surface pressure had re-increased to