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

• disordered phase. In the analysed case, the self-assembly process is steered by thermal annealing, which provides additional energy, enabling equilibration. The method allows for switching from the formation of meandering, not well-organized chains to a well-ordered phase. Deposition of the molecules on a

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

• treatment, that is after a thermally activated vacancy forming process, but also after storage at room temperature for several days. At room temperature the energy for vacancy formation on clean substrates is not supplied. However, at room temperature the switching of C60 from bright–to-dim and vice versa

• of the ac tunnelling current achieved by modulating the sample bias after switching off the feedback loop. The single crystal Au(111) substrate (MaTecK, Germany) was cleaned in UHV by cycles of Ne+ ion sputtering (1 kV, 10 min) and thermal annealing (600 °C, 20 min). The cleanliness was checked by

Influence of the shape and surface oxidation in the magnetization reversal of thin iron nanowires grown by focused electron beam induced deposition

• Luis A. Rodríguez,
• Lorenz Deen,
• Rosa Córdoba,
• César Magén,
• Etienne Snoeck,
• Bert Koopmans and
• José M. De Teresa

Beilstein J. Nanotechnol. 2015, 6, 1319–1331, doi:10.3762/bjnano.6.136

• . All results shown in Figure 2 correspond to the average of more than 100 hysteresis loops. Given the sharp switching transitions observed, a high level of reproducibility can be inferred. The observed decrease of HC with the width was also observed in polycrystalline cobalt nanowires grown by FEBID

• already multidomain-type, as shown in Figure 10. Indeed, for nominal thicknesses of 30 and 35 nm, the switching is produced through the formation and displacement of several magnetic domains along the nanowire length. The example of the 30 nm nanowire is shown in Figure 10a. For tNom = 40 and 50 nm, the

Magnetic properties of iron cluster/chromium matrix nanocomposites

• Arne Fischer,
• Robert Kruk,
• Di Wang and
• Horst Hahn

Beilstein J. Nanotechnol. 2015, 6, 1158–1163, doi:10.3762/bjnano.6.117

• clusters one can assume that FM spins residing on the surface are exchange-coupled to the AFM neighbors with a strength determined by the exchange integral J. The FM/AFM interaction keeps all the spins of the cluster along the unidirectional anisotropy axis. During the magnetization switching process the

• external magnetic field flips the magnetization in the opposite direction. The switching field must overcome the FM/AFM coupling which is proportional to J multiplied by the cluster surface area πR2, where R is the cluster radius. On the other hand the bigger the total magnetic moment of the cluster (which

• is proportional to the number of magnetic moments per cluster and, thus, to the volume, i.e., to R3) the higher is the torque induced by the external magnetic field and the easier is the rotation away from an easy axis. Thus the switching field is proportional to the ratio J·R2/R3, which eventually

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• directionally oriented monolayers when the molecule contains two different terminal groups that each have affinity for the substrate [30]. In particular, LB films have been used to analyze different properties and explore potential applications including molecular switching behavior [35][36], rectifying

Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy

• M. Kalyan Phani,
• Anish Kumar,
• T. Jayakumar,
• Walter Arnold and
• Konrad Samwer

Beilstein J. Nanotechnol. 2015, 6, 767–776, doi:10.3762/bjnano.6.79

• methodology eliminates repeated switching between an unknown specimen and a reference specimen for quantitative measurement of the indentation modulus. The calibration procedure is based on the equation: is governed by the elastic properties of the specimen and the tip. The relation between the indentation

Statistics of work and orthogonality catastrophe in discrete level systems: an application to fullerene molecules and ultra-cold trapped Fermi gases

• Antonello Sindona,
• Michele Pisarra,
• Mario Gravina,
• Cristian Vacacela Gomez,
• Pierfrancesco Riccardi,
• Giovanni Falcone and
• Francesco Plastina

Beilstein J. Nanotechnol. 2015, 6, 755–766, doi:10.3762/bjnano.6.78

• to handle the diagonalization of the total Hamiltonian H′(x) = H(x) + V (x), which describes the gas after switching on the potential. In particular, the perturbed eigenfunctions in presence of the excited impurity can be written in terms of the parabolic cylinder functions with normalization

• . Lowest and highest occupied valence states for the neutral fullerene molecule (C60) and corresponding valence states in the ionized fullerene molecule (). The sudden switching mechanism leads most of the content of the unperturbed Fermi state to be found in a state lying about 0.22 eV below the perturbed

• effects induced by core hole creation (see also below in Figure 2). Squared overlap integrals in a spin 1/2 trapped gas of 122 particles with a sudden switching impurity potential characterized by the critical exponent value α = 0.1 (see also Figure 3). The lowest occupied (v = 0, ε0 = 0.5 eV) and highest

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• ), low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon

• , we analyze the total current switching caused by the phase decoherence of electrons by placing a strong photon flux in one or both of the interferometer arms. This structure has the advantages that it does not require a p–n junction, it can operate at subwavelength resolution, its dimensions are very

Manipulation of magnetic vortex parameters in disk-on-disk nanostructures with various geometry

• Maxim E. Stebliy,
• Alexander G. Kolesnikov,
• Alexey V. Ognev,
• Alexander S. Samardak and
• Ludmila A. Chebotkevich

Beilstein J. Nanotechnol. 2015, 6, 697–703, doi:10.3762/bjnano.6.70

• disk-on-disk system turns from a homogeneous magnetic state into the state with antiparallel magnetization due to the magnetization switching in the small disk (point 2). As can be observed, there is a step in the hysteresis loop. With further decrease of the field the magnetic vortex emerges in the

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• capability to investigate cryogenic samples in the HZB-TXM, the electronic structure of individual hybrid colloid particles in their hydrated environment were analysed [63]. Here, the structural homogeneity of nanoparticles in the hybrid particle was examined. Nanoscale valence changes in resistive switching

• thin film devices (SrTiO3) could be demonstrated [64]. The change of resistance in a RRAM device could be assigned to a redox-process. The switching filament could be allocated to extended growth defects which are already present in the virgin films. Synthesis of anisotropic core-shell Fe3O4@Au

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• would allow switching the chain on and off [51]. The contact can also be considered in the context of doping since electrons can be transferred from the electrodes to the chain (charge transfer doping) [47], thus increasing the carrier density. The Fermi level of metallic contacts would be aligned to

• by one (switching between odd and even number of atoms) can change the direction of rectification [52]. On the other hand, asymmetric contacts, e.g., different metals or a metal and a carbon contact at the two ends of the chain, should lead to rectification. It has also been proposed that switching

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• controller, as it is also equipped with a low-voltage piezo-drive output. To drive two scanners independently, external control electronics are attached to the controller, which allow for a switching between the high- and low-voltage output. Additionally, this electronics allows one to hold the low-voltage

• output at any level when switching from the low-voltage output to the high-voltage output and vice versa. As our AFM setup is equipped with two independent scanners to combine both, a large field of view and a high spatial resolution, these hold electronics allow to drive the small-area scanner directly

• frequency of 14 kHz while carrying the open-loop scanner. For closed-loop operation of the AFM, this piezo is equipped with a strain gauge sensor which is read out by the AFM controller. Results and Discussion Characterization of the microscope For successful switching from the large scanner to the nested

Electrical properties of single CdTe nanowires

• Elena Matei,
• Camelia Florica,
• Andreea Costas,
• María Eugenia Toimil-Molares and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2015, 6, 444–450, doi:10.3762/bjnano.6.45

• switching from deposition inside the nanopore to deposition on the surface. This effect was used to determine the time necessary for complete filling whereby the process can be stopped earlier. The nanowires growing from caps on the surface (indicating complete pore filling) are more difficult to harvest

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• amplitudes – actually, the peak-voltage of the low-frequency square signal – were 0 Vp (planar alignment), 3 Vp (an intermediate state between threshold and saturated state) and 8 Vp (perpendicular orientation). The reversible character of the switching was monitored by following a predetermined bias voltage

• this work, since more electronic components are required for the EEC to fit these features which, anyhow, do not invalidate the above conclusions since they are fairly small. Reversibility of switched MWCNT cells The switching reversibility has been tested by running several batches of MWCNT-doped

Tunable light filtering by a Bragg mirror/heavily doped semiconducting nanocrystal composite

• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2015, 6, 193–200, doi:10.3762/bjnano.6.18

• exploited in several types of devices, such as distributed feedback lasers [11][12][13][14][15], sensors [16][17], absorption enhancement for photovoltaics [18] or in dye-sensitized solar cells [19][20][21]. Furthermore, nanoparticle-based photonic crystals have been employed for switching applications [22

• chemically tunable Cu2−xSe NCs and electrochemically switchable NC films of ITO. In both cases switching is based on a modulation of their carrier density and, thus, this combination will ultimately result in tunable, broadband light transmission. We model the structure by implementing the transfer matrix

• reversibly tuned by electrochemical post-treatment leading to a switching of the plasma frequency throughout the NIR spectral region [33][36][37]. Taken altogether, the proposed theoretical framework is appropriate to describe the tuning of light absorption with doped semiconductor NCs in a dispersion or in

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• of the membrane. This is also consistent with the observation that switching the fuel cell from OCV to a current density of j = 140 mA/cm2 increases the transmission in the membrane. The changes of transmission (“grey value” in the X-ray radiograph) though the MEA are shown in Figure 15. The water

Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

• Christina Rosman,
• Sebastien Pierrat,
• Marco Tarantola,
• David Schneider,
• Eva Sunnick,
• Andreas Janshoff and
• Carsten Sönnichsen

Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257

• –substrate impedance sensing (ECIS) ECIS measurements were performed according to [38]. A custom-built ECIS system was employed, consisting of a lock-in amplifier (SR830, SRS, Inc., Sunnyvale, CA), an internal oscillator, and a homemade multiplexer for automatic analog stepwise switching between connections

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

• parameters, such as switching to more polar solvents to compensate the electron deficiency for Au@Fe3O4 flowerlike particles [81], or for Au@MnO flowerlike particles in situ formation of gold particles without surface protection caused by thiol addition [58]. Phase-separated vs ternary-phase nanoparticles

Hybrid spin-crossover nanostructures

• Carlos M. Quintero,
• Gautier Félix,
• Iurii Suleimanov,
• José Sánchez Costa,
• Gábor Molnár,
• Lionel Salmon,
• William Nicolazzi and
• Azzedine Bousseksou

Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232

• –shell nanoparticles and multilayer thin films or nanopatterns. These systems combine, often in synergy, different physical properties (optical, magnetic, mechanical and electrical) of their constituents with the switching properties of spin-crossover complexes, providing access to materials with

• laser power required for a complete spin-state switching process was reduced by around 70%. It is interesting to note here that a similar strategy for low power, laser switching was also developed using the strong infrared absorption of the polymer matrix in a polymer–SCO composite material [24]. This

• Talham to study the photoinduced switching of the magnetism of KjNik[Cr(CN)6]l@RbaCob[Fe(CN)6] heterostructures [27]. These nanoscale heterostructures exhibited a photo-response not seen in either constituent on its own (Figure 5). The changes induced by the light irradiation occur in the RbCoFe lattice

UHV deposition and characterization of a mononuclear iron(III) β-diketonate complex on Au(111)

• Irene Cimatti,
• Silviya Ninova,
• Valeria Lanzilotto,
• Luigi Malavolti,
• Luca Rigamonti,
• Brunetto Cortigiani,
• Matteo Mannini,
• Elena Magnano,
• Federica Bondino,
• Federico Totti,
• Andrea Cornia and
• Roberta Sessoli

Beilstein J. Nanotechnol. 2014, 5, 2139–2148, doi:10.3762/bjnano.5.223

• the switching properties can be dramatically altered by the interaction of the organic ligands with the surface. For instance, the electrical switching of Fe((H2B-pz)2)2(phen) can be observed in the second molecular layer deposited on Au(111), but the molecules of the first layer cannot be switched

• [36]. Similarly, isolated Fe(phen)2(NCS)2 molecules cannot be switched on Cu(100). On the other hand, the introduction of an interfacial layer of CuN on Cu(100) allows switching between the HS and the LS state [33][35]. A slightly different situation was observed for a submonolayer of Fe((H2B-pz)2)2

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• reduced to below ≈4 fs, the data for the optical field enhancement obtained from SERS and electrochemical measurements of the self-organized Au nanoarrays indicate an application capability in areas of light harvesting [34], ultra-sensitive detection (SERS), spintronics [64] and optical switching [65

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• earlier study, one of the azaBODIPY-CNO derivatives showed a pH-dependent switching (on–off) of the fluorescence, a feature that could also be observed inside the cells. The latter CNO nanomaterial was subject to co-localization experiments with Lysotracker Red dye and it was confirmed by high-resolution

Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

• Anna Pohl and
• Ingrid M. Weiss

Beilstein J. Nanotechnol. 2014, 5, 1823–1835, doi:10.3762/bjnano.5.193

• sensor system when switching from the running buffer to injection mode. The peptide solutions were sequentially injected on the same channel, first ES9 and then AS8. The phase signals for 200 µM peptide injections according to Table S4 (Supporting Information File 1) are shown in Figure 6. The observed

Experimental techniques for the characterization of carbon nanoparticles – a brief overview

• Wojciech Kempiński,
• Szymon Łoś,
• Mateusz Kempiński and
• Damian Markowski

Beilstein J. Nanotechnol. 2014, 5, 1760–1766, doi:10.3762/bjnano.5.186

• behavior is consistent with the CELTC model. Recent measurements of ACFs + CCl4 confirm this idea and Figure 6 shows that there is a clear difference between the influence of dipolar and non-dipolar guest molecules, represented by the value of the T0 parameter. Another interesting feature is the “switching

The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

• Edwin J. Devid,
• Paulo N. Martinho,
• M. Venkata Kamalakar,
• Úna Prendergast,
• Christian Kübel,
• Tibebe Lemma,
• Jean-François Dayen,
• Tia. E. Keyes,
• Bernard Doudin,
• Mario Ruben and
• Sense Jan van der Molen

Beilstein J. Nanotechnol. 2014, 5, 1664–1674, doi:10.3762/bjnano.5.177

• the physical properties depend strongly on their intrinsic low and high spin states (LS, S = 0 and HS; S = 2). Integrated spin transition (ST) units may be considered as potential electronic components in the construction of switching molecular devices [16][17], a vision for which the control of the