Ferromagnetic behaviour of ZnO: the role of grain boundaries

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2016, 7, 1936–1947, doi:10.3762/bjnano.7.185

• functional theory calculations. For the cluster with about 200 atoms in an effective electrostatic field formed by the rest of the simulated system the electronic structure was determined. The calculation show that for single-crystalline ZnO the energy difference between highest occupied molecular orbital

• (HOMO) and lowest unoccupied molecular orbital (LUMO) is quite high and reaches about 4 eV. However, this difference for the sample containing the disordered GB area diminishes almost to zero. Moreover, energy of the lowest magnetic triplet state for GB is only 0.2 eV higher than the closed shell ground

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

• Huijuan Zhang,
• Fuqiang Wu,
• Yazhen Li,
• Xiping Yang,
• Jiamei Huang,
• Tingting Lv,
• Yingying Zhang,
• Jianzhong Chen,
• Haijun Chen,
• Yu Gao,
• Guannan Liu and
• Lee Jia

Beilstein J. Nanotechnol. 2016, 7, 1861–1870, doi:10.3762/bjnano.7.178

• MIF. Blood samples (each 0.5 mL) were collected in heparinized tubes from the orbital venous plexus at 0.5, 1, 1.5, 2, 4, 8, 12, and 24 h after oral administration. All blood samples were immediately processed by centrifugation at 4000 rpm for 8 min, and the plasma samples were stored at −20 °C before

• MCNs equivalent to the same dosage of MIF. Blood samples (each 0.5 mL) were collected into heparinized tubes from the orbital venous plexus at different time points after oral administration. Pharmacokinetic parameters of different MIF formulations. Acknowledgements This work was supported by the

Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study

• Veronique Dupuis,
• Anthony Robert,
• Arnaud Hillion,
• Ghassan Khadra,
• Nils Blanc,
• Damien Le Roy,
• Florent Tournus,
• Clement Albin,
• Olivier Boisron and
• Alexandre Tamion

Beilstein J. Nanotechnol. 2016, 7, 1850–1860, doi:10.3762/bjnano.7.177

• -collinear structure at the interface with the matrix [34] remains below the threshold of 50% of the bulk average magnetic moment per atom. From a qualitative overview of the measured data on the annealed samples, we generally observed an enhancement of the spin and orbital moments at the Co L edge for the

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• function of graphene before and after interaction with heavy metals, was calculated by using the following equation [56]: where IP is the ionization potential of the graphene supercell and EHOMO-LUMO is the energy difference between the highest occupied molecular orbital (HOMO) and the lowest unoccupied

• molecular orbital (LUMO). It should be mentioned that in reality Equation 6 is more complex, since the effect of buffer layer, doping, functional groups (hydroxyl, carboxyl and epoxy groups) on the electronic properties of graphene cannot be ignored. The ionization potential was estimated as the energy

Microwave synthesis of high-quality and uniform 4 nm ZnFe₂O₄ nanocrystals for application in energy storage and nanomagnetics

• Christian Suchomski,
• Ben Breitung,
• Ralf Witte,
• Michael Knapp,
• Sondes Bauer,
• Tilo Baumbach,
• Christian Reitz and
• Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

• Fe in the Fe(III) state [33][34]. The apparent asymmetry of the Fe 2p peaks suggests that the inversion parameter must be greater than zero. The main peaks at binding energies of (724.59 ± 0.05) eV and (710.65 ± 0.05) eV for the 2p1/2 and 2p3/2 orbital lines, respectively, correspond to octahedral

Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds

• Albert Ivancic,
• Fliur Macaev,
• Fatma Aksakal,
• Veaceslav Boldescu,
• Serghei Pogrebnoi and
• Gheorghe Duca

Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112

• stabilizing the InhA–isoconazole complex. To assess these interactions, frontier molecular orbital calculations were performed for the active site of InhA and isoconazole obtained from docking. Isoconazole was predicted to be an active inhibitor of InhA with the analysis of the molecular docking and electron

• active site of InhA and isoconazole in order to discuss these interactions with the frontier molecular orbital (FMO) analysis of the electron density distribution. The main carriers used in our particles are β-cyclodextrin, sodium alginate, and chitosan. β-Cyclodextrin (β-CD), a cyclic oligosaccharide

• interactions with isoconazole. Multiple hydrophobic contacts of amino acids with the inhibitor were indicated by green spheres in Figure 12b. Frontier molecular orbital analyses The analysis of specificity of the enzyme–ligand interaction is closely related to the analysis of frontier orbitals (HOMO and LUMO

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• moieties [34]. Furthermore, certain defects also produce nanotube curvature, which in turn creates π-orbital mismatch and consequently creates more active sites on the CNT. In any case, the presence of these defects is known to affect the band structure of the carbon nanotubes and thus can be studied by

• evacuate the charges accumulated on the surface but also reduces the heating effects of the material due to nonradiative recombination. Core loss EELS C K-edge Most nanoparticles are attached to sites with defects and changes in CNT curvature, creating π-orbital mismatches that increase the reactivity and

Role of solvents in the electronic transport properties of single-molecule junctions

• Katharina Luka-Guth,
• Sebastian Hambsch,
• Andreas Bloch,
• Philipp Ehrenreich,
• Bernd Michael Briechle,
• Filip Kilibarda,
• Torsten Sendler,
• Dmytro Sysoiev,
• Thomas Huhn,
• Artur Erbe and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 1055–1067, doi:10.3762/bjnano.7.99

• dependent transmission function of a scatterer: It assumes that the current is carried by an electronic mode that is formed by a single molecular orbital at energy E0(V), coupled to the left and right electrode via the coupling constants ΓL and ΓR, respectively. The coupling gives rise to broadening of the

• shape. In case of symmetric coupling ΓR = ΓL the position of the energy level is independent of the applied voltage. Usually it is assumed that the molecular orbital that is closest to the Fermi energy, i.e., the highest occupied molecular orbital (HOMO) or the lowest unoccupied molecular orbital (LUMO

• a unique molecular orbital with well-defined coupling constant, unless a solvent molecule anchors to the electrodes and forms a single-molecule contact. We therefore try to fit all stable I–Vs of all solvents to both models to test how well they can be reproduced by the models and if they can

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• substrate with a passivated tip, resulting in triangular shaped atoms [Sweetman et al. Nano Lett. 2014, 14, 2265]. The symmetry of the features, and the well-established nature of the dangling bond structure of the silicon adatom means that in this instance the contrast cannot arise from the orbital

• flexible tip exploring an asymmetric potential around an atom unrelated to its electronic orbital configuration. Our simulations show that the local atomic environment (i.e., the position of the other atoms on the surface) can provide such a potential. A distinction must therefore be drawn between what

• might be termed ‘orbital’ imaging, which explicitly images the orbitals of single atoms, and ‘sub-atomic’ imaging, which can arise from a number of multi-atom effects. Therefore, we suggest that interpretation of ‘sub-atomic’ features that share a symmetry with either the direct backbonding atoms, or

High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

• Benjamin Grévin,
• Pierre-Olivier Schwartz,
• Laure Biniek,
• Martin Brinkmann,
• Nicolas Leclerc,
• Elena Zaborova and
• Stéphane Méry

Beilstein J. Nanotechnol. 2016, 7, 799–808, doi:10.3762/bjnano.7.71

• a flat band alignment. Under illumination, the holes quasi-Fermi level remains aligned with the Fermi level of the grounded substrate, while the quasi-Fermi level of the electrons is located near the lowest unoccupied orbital level (LUMO) of the acceptor units. As a consequence, the local vacuum

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

• term θsym and an orbital, effective magnetic field θa in the space of the vibrational modes. The latter interpretation is based on the fact that the corresponding force takes a Lorentz-like form. Using and noting that = = 0, we obtain the explicit expressions Here we have introduced the notation

• in the rest of the paper, the simple case where the nanoscopic system is represented by a molecule modeled as a single electronic level (M = 1) locally interacting with a single vibrational mode (N = 1, see Figure 1). This means that the focus is on a molecular (or quantum dot) electronic orbital

• separated by an energy of the order of 0.5 eV [85]. Furthermore, the energy of the molecular orbital can be tuned by varying the gate voltage VG and unless otherwise stated we do not consider time-dependent perturbations. We will focus on the center-of-mass mode as the only relevant vibrational mode for the

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

• densities of states, and therefore Σx(ε) is taken at the zero-bias Fermi energy ε = μx = EF = 0 and (ii) electrode bandwidths of ≈4|tL,R| much larger than any other characteristic energies (e.g., orbital energy offsets relative to the Fermi level and widths functions ΓL,R). This is the rationale to extend

• the case [22][23][24], the transport is dominated by a single molecular orbital. Impact on the I–V curves Figure 2 depicts various I–V curves computed for this case and various sizes of the extended molecule Next ≥ N = 1. While agreeing with the exact I–V curves at lower biases (eV < 2εM), the

• Hμ,ν may depend on the bias V (e.g., Stark shift of orbital energies) [22][41][42][43] is particularly noteworthy. (ii) Considering a specific molecule or even a specific class of homologous molecular series, the demonstration of the envisaged invariance property would have been restricted to certain

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

• . While organic π-conjugated systems are capable of more efficient charge transport along the molecular backbone due to the electron delocalization. This fundamental phenomenon is induced by the difference in the energy gap between the lowest unoccupied molecular orbital (LUMO) and highest occupied

• molecular orbital (HOMO). In conjugated systems this gap is smaller (about 3 eV) than the HOMO–LUMO gap of saturated molecules (about 7 eV) [17]. The conductance of a conjugated system depends on several factors, and not only the length of the conjugated system and its anchoring groups have a large

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• used throughout this study were grown in 250 mL Erlenmeyer flasks containing 150 mL modified Bold's Basal Medium (BBM, pH 6.8) with 50% less nitrate and without vitamins [43][44][45]. The cultures were shaken continuously horizontally (Labworld Orbital Shaker 20) and placed in a temperature-controlled

Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

• Yongfeng Tong,
• Tingming Jiang,
• Azzedine Bendounan,
• Makri Nimbegondi Kotresh Harish,
• Angelo Giglia,
• Stefan Kubsky,
• Fausto Sirotti,
• Luca Pasquali,
• Srinivasan Sampath and
• Vladimir A. Esaulov

Beilstein J. Nanotechnol. 2016, 7, 263–277, doi:10.3762/bjnano.7.24

• higher energy and broadening of the C 1s peak is also observed. In NEXAFS measurements, for molecular adsorption in vacuum, the spectrum is characterized by a sharp peak at about 285 eV related to the π*1 orbital of thiophene, which disappears for liquid phase adsorption, indicating breaking of the

• liquid phase adsorption. This was deduced from changes in the Se 3p peak positions and strong differences in NEXAFS spectra. In adsorption in UHV, a strong peak due to the selenophene π orbital was observed, whereas it was very strongly reduced for liquid phase adsorption. Along the lines of the other

• dominated by a peak at 285.5 eV ascribable to the π*1 orbital of selenophene. For Sample 2 this peak is much weaker. We also see that for Sample 1 in the XPS 3d spectrum, the B peak is most intense, whereas for Sample 2 it is the A peak that dominates the spectrum. In this case, there is also a more

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

Effects of electronic coupling and electrostatic potential on charge transport in carbon-based molecular electronic junctions

• Richard L. McCreery

Beilstein J. Nanotechnol. 2016, 7, 32–46, doi:10.3762/bjnano.7.4

• structurally complex, the simple model yields significant correlations between theoretical predictions and experimental observations. In particular, four general questions are considered to evaluate the model: First, how does bonding between the carbon contact and the molecular layer alter the orbital energies

• of Gaussian09 for Windows. Orbital visualization with Gaussview used the default isovalue of 0.02, which is commonly used to represent the majority of the electron density. Predictions of charge transfer within model molecules used the Mulliken charges calculated during the DFT analysis. There is

•  1d will be used in all calculations and figures unless noted otherwise. Also shown in Figure 1 are the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) for G9 and AB. In all cases, the orbital energies are stated relative to a vacuum reference, consistent

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

• and performed density function theory (DFT) calculations of the OPE3 molecular junction. All calculations were optimized using a TZP Slater-type orbital local basis-set and the PBE GGA functional. We stretch the molecular junction starting from the configuration shown in the left panel of Figure 5a

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

• Benjamin Siegert,
• Andrea Donarini and
• Milena Grifoni

Beilstein J. Nanotechnol. 2015, 6, 2452–2462, doi:10.3762/bjnano.6.254

• enormous anisotropies in both spin and orbital dipole moments [9]. Furthermore, recent experimental findings for cobalt pththalocyanine in a scanning tunneling microscopy (STM) setup [10] suggest that many-body correlations play an important role in the interpretation of the transport measurements. In a

• should be observed at magnetic fields of a few teslas. The paper is organized as follows: We first derive a microscopic Hamiltonian for CuPc in the frontier orbital basis which includes exchange correlations and the SOI. This Hamiltonian is diagonalized exactly and used in further spectral analysis and

• molecule is given by , describes electronic interactions and accounts for the spin–orbit interaction (SOI). Single-particle Hamiltonian for CuPc The one-body Hamiltonian , written in the atomic basis , reads where α is a multi-index combining atomic species and orbital quantum number at position rα, see

High electronic couplings of single mesitylene molecular junctions

• Yuki Komoto,
• Shintaro Fujii,
• Tomoaki Nishino and
• Manabu Kiguchi

Beilstein J. Nanotechnol. 2015, 6, 2431–2437, doi:10.3762/bjnano.6.251

• , electronic conductance of the single molecular junction can be described by two parameters of (i) the electronic coupling between electrodes and molecule and (ii) the relative energy level alignment of the conduction orbital of molecule with respect to the Fermi level of the metal electrodes. By fitting the

• experimentally obtained I–V characteristics to the Breit-Wigner model, the metal–molecule coupling Γ, and energy difference between Fermi level and conduction orbital ε0 are obtained. This I–V analysis has been applied for molecular junctions with a variety of anchoring groups. For example Γ = 60 meV and ε0

• of the conduction orbital, and the strength of the coupling between molecule and left and right electrodes, respectively. The current in the molecular junction is represented by where n is the number of bridging molecules. The formula for the current in molecular junctions (Equation 3) is obtained

Vibration-mediated Kondo transport in molecular junctions: conductance evolution during mechanical stretching

• David Rakhmilevitch and
• Oren Tal

Beilstein J. Nanotechnol. 2015, 6, 2417–2422, doi:10.3762/bjnano.6.249

• response to stretching and the molecular orbital on which the single spin is localized [23]. Such coupling may explain why two different quantities, namely, the side peak voltage that indicates the onset of vibration activation and the zero-bias Kondo amplitude, change their evolution trends at the same

• tunneling between the Ag electrodes can also be considered as a source for background conduction [35]. We speculate that the different response of the background and the Kondo conductance to junction elongation (Figure 2c,d) comes from the different response of the orbital hybridization at the metal

Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains

• Carlos Sabater,
• Carlos Untiedt and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2015, 6, 2338–2344, doi:10.3762/bjnano.6.241

• is due to the difference in numbers of conductance channels per atom and their associated transmission probabilities [12][13]. Au has just one conductance channel with nearly perfect transmission associated with the 6s orbital, while for Pt the 5d orbitals give rise to additional conductance channels

Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C–C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy

• , which increases by 0.07 Å from g to B. Such an elongation occurs because the C1 orbital modifies from sp2 to sp3 hybridization, which results in a displacement of the valence electron density of C1 from the C1–C2 bond to the newly formed C1–Al bond, as recently discussed for self-assembled monolayers

• appreciable filling was observed as this state displays an energy range as large as 4 eV with its main peak below the Fermi energy level [15]. From the results in Figure 3 we add that the orbital corresponding to the LUMO+2 of the undistorted free molecule becomes the LUMO+3 of the V-shaped gas phase molecule

Nonconservative current-driven dynamics: beyond the nanoscale

• Brian Cunningham,
• Tchavdar N. Todorov and
• Daniel Dundas

Beilstein J. Nanotechnol. 2015, 6, 2140–2147, doi:10.3762/bjnano.6.219

• -boundary quantum Liouville equation [17]. These approaches will be discussed in more detail later. Electrons are described within a spin-degenerate single-orbital orthogonal nearest-neighbour tight-binding model with parameters fitted to the elastic properties of bulk gold [18]. The nearest-neighbour

Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• based on minimal model Hamiltonians are largely focused on the Anderson impurity dot model which consists a single molecular electronic orbital directly coupled to biased metal leads, as well as to a particular vibrational mode [1]. Since the same molecular orbital is assumed to extend both contacts

• thermopower, a linear response quantity, also referred to as the Seebeck coefficient, is utilized as an independent tool for probing the energetics of molecular junctions [17][18][19][20][21][22][23][24]. Experimental efforts identified orbital hybridization, contact-molecule energy coupling and geometry, and