Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• Republic 10.3762/bjnano.7.65 Abstract We investigate the rich magnetic switching properties of nanoscale antidot lattices in the 200 nm regime. In-plane magnetized Fe, Co, and Permalloy (Py) as well as out-of-plane magnetized GdFe antidot films are prepared by a modified nanosphere lithography allowing

• for non-close packed voids in a magnetic film. We present a magnetometry protocol based on magneto-optical Kerr microscopy elucidating the switching modes using first-order reversal curves. The combination of various magnetometry and magnetic microscopy techniques as well as micromagnetic simulations

• delivers a thorough understanding of the switching modes. While part of the investigations has been published before, we summarize these results and add significant new insights in the magnetism of exchange-coupled antidot lattices. Keywords: antidot lattice; first-order reversal curves; Kerr microscopy

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• switching operations. (a) Scheme of an AFM cantilever coated with a porous silica film in the fluid cell with deflection readout. (b) Backscattered electron SEM image of the cross section of a silica-coated cantilever. Cantilever deflection as a function of the relative humidity. (a) GISAXS pattern of

Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

• consequence, intriguing nonlinear phenomena, such as hysteresis, switching, and negative differential conductance have been observed in molecular junctions. In conducting molecules, either the center of mass oscillations [9], or thermally induced acoustic phonons [10] can be the source of coupling between

• of gigahertz. Recently, it has been found that phenomena such as switching, hysteresis, as well as multistability can be observed in NEMS [13]. NEMS have been proposed as high sensitive position and mass sensors [14][15][16][17][18][19][20]. Recently, research at the nanoscale has focused not only on

• and NEMS. In this review, we analyze the adiabatic regime, realized when the internal vibrational modes have frequencies smaller than the hopping rate. Within this regime, one can observe phenomena such as switching, multistability and hysteresis in molecular junctions or NEMS, and study the physics

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• rather than operators. For nonorthonormal basis sets, the nondiagonal overlap matrix SC would replace the identity matrix 1C of Equation 1. Switching between orthonormal and nonorthonormal basis sets leaves the diagonal matrix elements (on-site energies) unchanged while renormalizing the nondiagonal

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

Molecular machines operating on the nanoscale: from classical to quantum

• Igor Goychuk

Beilstein J. Nanotechnol. 2016, 7, 328–350, doi:10.3762/bjnano.7.31

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• power switches. Each switching process results in a melting of the contact surface and after several hundred events in a degradation of the device properties. Therefore, the chemical and structural properties of these surfaces are of major interest. Since the melting zone is typically macroscopically

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

• Riccardo Frisenda,
• Mickael L. Perrin and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 2477–2484, doi:10.3762/bjnano.6.257

• at the interface between the molecule and the metallic electrodes or in the electronic configuration. Finally, to investigate the switching dynamics of OPE3 between the different configurations (1–5) we recorded the conductance of junction 1 as a function of time (see Figure 6a). The traces have been

• a higher value and then it switches back to the original values shortly thereafter. For increasing voltage, the switching behavior becomes more frequent, resembling telegraph noise. This points to a two-level system characterized by two different conductance values [32]. By comparing the conductance

• notice that for bias voltages higher than 0.20 V, some of the two-level fluctuations involve configurations 4 and 5b, and four levels of current are present. In conclusion we observed fluctuations induced by the bias voltage, two-level switching between 3 and 5a, above 0.16 V, and four-level switching

An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

• is a solid-state mechanism that occurs within the nanoparticle. It corresponds to a switching of the magnetic moment between two equilibrium positions. The latter is due to the physical rotation of nanoparticle within the colloidal solution. Changing in orientation of the magnetic moment of a

Conformational switching of ethano-bridged Cu,H₂-bis-porphyrin induced by aromatic amines

• Simona Bettini,
• Emanuela Maglie,
• Rosanna Pagano,
• Victor Borovkov,
• Yoshihisa Inoue,
• Ludovico Valli and
• Gabriele Giancane

Beilstein J. Nanotechnol. 2015, 6, 2154–2160, doi:10.3762/bjnano.6.221

• -porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the

• in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions. Keywords: aromatic amines; bis-porphyrin; conformational switching; Langmuir film; surface plasmon

• subphase, which is further confirmed by reflection spectroscopy at the air/subphase interface. In fact, a red shift of the Soret band by about 10 nm was induced by the aniline, thus suggesting the syn-to-anti conformational switching in the Cu,H2-Por2 molecules (Figure 4b). This effect is similar to that

Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

• Philipp Leinen,
• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2015, 6, 2148–2153, doi:10.3762/bjnano.6.220

• of or as obtained from the SPM. Switching between the log(I) and Δf color-codes can be performed by pressing a custom-defined action button on the Apex device. Results and Discussion We begin the discussion of our results by characterising the precision of the implemented visual feedback system

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

• be particularly appealing if device properties (such as switching power, speed, and stability) could be engineered and controlled by chemical design. By optimizing the on-state conductance, a large on/off ratio can be achieved, which is essential for the reliable operation of a molecular switch. In

• anchored to the surface via an oxygen atom. The reversible switching of the junction allowed us to explore the effect of molecular interaction on the molecular conductance. Here we extend this study and show that switching can be controlled by voltage pulses as well as by mechanical manipulation of the tip

• 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

High I_on/I_off current ratio graphene field effect transistor: the role of line defect

• Mohammad Hadi Tajarrod and
• Hassan Rasooli Saghai

Beilstein J. Nanotechnol. 2015, 6, 2062–2068, doi:10.3762/bjnano.6.210

• carrier mobility and velocity of graphene is utilized in ballistic and high switching speeds devices [3][4]. However, the very large off-current of graphene at room temperature, which is associated with the small band gap, renders it incapable of being integrated as a building block for pure carbon-based

• -current decrease is much more significant than the on-current reduction in ELD-GNRFET. The results indicate that on/off ratio improved 30% in the defected transistor. The simulating of the average of transconductance and the subthreshold swing describe the switching-on and the immunity of the short

• channel effects in the switching-off performance. In this study, the transconductance decreased from gm = 94 μS in the ideal transistor to gm = 55.7 μS for the defected transistor. The subthreshold swing, which is defined as ∆VG/∆log(∆ID) at the subthreshold region in GNRFET, was S = 166.9 mV/dec, whereas

Conductance through single biphenyl molecules: symmetric and asymmetric coupling to electrodes

• Karthiga Kanthasamy and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2015, 6, 1690–1697, doi:10.3762/bjnano.6.171

• to changes in bonding sites of the molecule on the electrodes, which have a great impact on conductance. The pronounced switching in conductance at times between 36–46 h has been characterized earlier as blinking of the thiol–gold bond, a characteristic of any molecule bonded to gold surface via

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• simultaneous FEBIE and FEBID processes, and are not caused by adsorbate diffusion (which is ignored by Equation 27–Equation 37). This competition and the resulting phenomenon of electron flux controlled switching between etching and deposition have been discussed in detail in [11][14]. The additional effects

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