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

• in the bulk [13]. The LE-µSR measurements were supported by theoretical studies [13]. Using molecular dynamics the simulations of 4800 atoms in a periodic box were performed for two grain boundaries. They permitted to simulate the atomic disorder in the grain boundary region. The simulation periodic

Evolution of the graphite surface in phosphoric acid: an AFM and Raman study

• Rossella Yivlialin,
• Luigi Brambilla,
• Gianlorenzo Bussetti,
• Matteo Tommasini,
• Andrea Li Bassi,
• Carlo Spartaco Casari,
• Matteo Passoni,
• Franco Ciccacci,
• Lamberto Duò and
• Chiara Castiglioni

Beilstein J. Nanotechnol. 2016, 7, 1878–1884, doi:10.3762/bjnano.7.180

• that observed with 457.9 nm excitation and are not reported in Figure 5. The three different analyzed regions display the typical spectral pattern of graphitic materials characterized by structural disorder [16][17][18], showing Raman features in the G-band region (1570–1650 cm−1), in the D-band region

In situ formation of reduced graphene oxide structures in ceria by combined sol–gel and solvothermal processing

• Jingxia Yang,
• Johannes Ofner,
• Bernhard Lendl and
• Ulrich Schubert

Beilstein J. Nanotechnol. 2016, 7, 1815–1821, doi:10.3762/bjnano.7.174

• . The D-band is related to a breathing mode of κ-point photons of A1g symmetry, and the G-band can be attributed to the splitting of the E2g stretching mode of graphite, which reflects the proportion of the sp2-hybridized carbon atoms [24]. The intensity ratio I(D)/I(G) represents the degree of disorder

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

• semiconductor with an extremely high resistivity extending to 108 Ω·cm, however, even a small deviation from the stoichiometric composition with a surplus of titanium ions results in n-type semiconducting properties [16]. Such observations lead to the undeniable conclusions that the defect disorder and

Antitumor magnetic hyperthermia induced by RGD-functionalized Fe₃O₄ nanoparticles, in an experimental model of colorectal liver metastases

• Oihane K. Arriortua,
• Eneko Garaio,
• Borja Herrero de la Parte,
• Maite Insausti,
• Luis Lezama,
• Fernando Plazaola,
• Jose Angel García,
• Jesús M. Aizpurua,
• Maialen Sagartzazu,
• Mireia Irazola,
• Nestor Etxebarria,
• Ignacio García-Alonso,
• Alberto Saiz-López and
• José Javier Echevarria-Uraga

Beilstein J. Nanotechnol. 2016, 7, 1532–1542, doi:10.3762/bjnano.7.147

• deviates from the bulk saturation value of magnetite (92 emu/g) [39]. Nevertheless, the deviation could be ascribed to different effects such as crystallinity of the samples as well as the impact of surface spin disorder, which increases at high temperatures [40]. At 5 K, saturation magnetization increases

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

• here [3][4][5][6][7][8]. The magnetic properties of spinel ferrites are known to be strongly dependent upon their size [9][10][11]. Part of the reason for this is that, for example, significant spin disorder occurs when the particle size is reduced to the nanometer level. Nevertheless, the cation site

• nanocrystalline solids and are often associated with spin canting, spin freezing and so forth. Although the origin of these effects is largely unclear, they are typically attributed to magnetic frustration, surface disorder and/or finite size effects [49][50]. However, the theoretical saturation magnetization

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• Raman spectrum (Figure 3c), which shows two bands centered at 1597 cm−1 (G band) and 1340 cm−1 (D band) typical of carbon with small graphitic domains. The G band results from the in-plane stretching of sp2-bonded (graphitic) carbon atoms, while the D band is induced by defects and disorder in the

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• surfactant solution. The reactions involved are carried out in argon atmosphere [117]. A typical disorder band in Raman spectrum gives proof of the sidewall functionalization. This sidewall functionalization not only improves purity and solubility, but it also changes the physical properties. In fact, the

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

• LC molecules, and the volume of the SWCNT itself is imperceptible. This appearance changes with the SWCNT reorientation, and an increase of the scattering is clearly visible in the photograph. The light scattering in the excited state is caused by the LC molecule disorder around the reoriented SWCNT

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

• formed by the acceptor units. In turn, the hole transport will be less affected, due to the longer length of the donor segments. Then, disorder-induced electron localization could be the origin of the local negative SPV contrasts. At this stage, we cannot definitely conclude this – particularly since the

Plasticity-mediated collapse and recrystallization in hollow copper nanowires: a molecular dynamics simulation

• Amlan Dutta,
• Arup Kumar Raychaudhuri and
• Tanusri Saha-Dasgupta

Beilstein J. Nanotechnol. 2016, 7, 228–235, doi:10.3762/bjnano.7.21

• disappearance of the residual disorder and stacking faults within the NW. This process is much slower as compared to that of the previous two stages. Healing of the nanostructure at this stage involves elimination of stacking faults, which is an activated process, thus exhibiting the observed slow rate. Most of

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• reduced number of layers. The D and D’ bands are caused by disorder in the graphene flakes. The D’ band is present when there are surface defects, such as charging or other impurities adsorbed onto the surface. The D band is caused by edge defects such as a “zig-zag” or “chair” shape on the edge. Edge

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• of an amorphous halo is indicative of a disorder-to-order type cubic-to-hexagonal phase transition [39]. The size of α crystallites ranged from 6 to 6.5 nm, and the size of β-phase crystals ranged between 18–21 nm. Interestingly, diffraction peaks corresponding to the cubic phase were hardly visible

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• Raman spectra: the disorder-induced D-band (around 1335 cm−1), D’-band (around 1602 cm−1, attributed to intravalley scattering activated through a double resonance process), and the tangential G-mode (at 1570 cm−1). The last feature is related to the E2g Raman-active mode, where the two atoms in the

• including the tips of vertically aligned carbon nanotubes. The information about the disorder and defect/damage induced by the functionalization is directly qualitatively inferred from the ID/IG ratio: in the pristine sample (blue curve) this ratio is 0.78, and increases to 1.69 for the as-functionalized

• ). The remaining disorder mode therefore indicates both the enhancement of disorder in the carbon lattice upon functionalization, and the increase in the amount of defects. This has been associated with the local carbon removal on the sidewall during the heating-induced desorption process, as for example

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• occurrence of the quantum confinement effect, demonstrating the most rapid weakening with the increase of N in ZnO/CdS heterostructures. The structural disorder of CdS nanoparticles was characterized by the Urbach energy (EU), spectral width of the CdS longitudinal optical (LO) phonon band and the relative

• notable variation in the degree of disorder of CdS nanoparticles is observed only in the initial stages of CdS growth (several tens of deposition cycles), indicating the preservation of the nanocrystalline state of CdS over a wide range of SILAR cycles. Keywords: CdS; nanoparticles; Raman spectroscopy

• SILAR method to form CdS NPs on an oxide substrate, its influence on the quantum efficiency of photoelectrochemical processes and the structural disorder of CdS NPs with an increasing number of SILAR cycles (N) is still unclear. The aim of this study was to investigate the foregoing features to make the

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2161–2172, doi:10.3762/bjnano.6.222

• cm−1, which can be assigned to the Zn–I vibration (expected at 166 cm−1). Single crystals of 2 were grown for X-ray diffraction analysis. Unfortunately, the exact structure determination was not possible due to substantial orientational disorder. The heterocubane core and the presence of iodine could

Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires

• Suvankar Das,
• Amitava Moitra,
• Mishreyee Bhattacharya and
• Amlan Dutta

Beilstein J. Nanotechnol. 2015, 6, 1970–1977, doi:10.3762/bjnano.6.201

• and suitability as novel thermoelectric devices [7]. This effect is found to be extremely prominent for ultrathin nanowires with diameters smaller than ≈20 nm [8]. The figure of merit can be further improved by introducing surface disorder without compromising the excellent electronic conductance [9

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

• Luc Aymard,
• Yassine Oumellal and
• Jean-Pierre Bonnet

Beilstein J. Nanotechnol. 2015, 6, 1821–1839, doi:10.3762/bjnano.6.186

• fracture of the C–C covalent bonds, leading to the formation of very reactive edge carbon atoms and unstable particles which agglomerate together. The degree of disorder for carbonaceous materials increases with increased milling time and is proportional to the d(002) distance, as previously established

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• , resulting in structural disorder. Severe continuous illumination may eventually lead to complete amorphization of the lattice at room temperature [36]. As demonstrated in Figure 4c–e, an ordered graphene lattice is transformed into a disordered two-dimensional (2D) carbon glass by continuous irradiation at

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• direction, kppd approaches kppd,eq and Equation 15 reduces to the conventional Shockley equation with ideality factor n = 1. Disorder and polycrystalline structure have a strong impact on the electrical transport in organic junctions, since the polarons can be trapped at defects. Consequently, the absolute

• value and the temperature dependence of RS strongly depend on disorder. Since either the electron- or the hole-type polaron can be trapped, the resulting two different bimolecular recombination processes can be modelled as two different currents, which thus gives rise to an effective two diode Shockley

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

• depends both on the effective dimensionality and the amount of topological/charge disorder in the system. The distribution of nanocrystal connectivity due to this disorder plays an essential role in determining the topological “landscape” for charge transport, which can be affected at the nanoscopic

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• deviations between the vacuum and matrix dipole moments arise from induction and polarization effects present only in the matrix, which influence the energy disorder. Furthermore, we calculated the width of the local density of states for additional charges (if a Gaussian shape is assumed, this is referred

• to as energy disorder, σ), the mean electronic coupling between molecules, , the mean number of neighbors, M, and the reorganization energy, λ. These results are shown in Table 2. These microscopic parameters can be used to calculate the charge carrier mobility [41]: where e is the electric

• × 10−6 cm2·V−1·s−1 for electrons, which can be compared to Alq3 having a hole mobility of 3.3 × 10−8 cm2·V−1·s−1 and an electron mobility of 9.2 × 10−8 cm2·V−1·s−1. The differences between AlOp3 and Alq3 mainly arise from different dipole moments, which lead to a higher energy disorder, σ, for Alq3. Al

Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

• Brett B. Lewis,
• Michael G. Stanford,
• Jason D. Fowlkes,
• Kevin Lester,
• Harald Plank and
• Philip D. Rack

Beilstein J. Nanotechnol. 2015, 6, 907–918, doi:10.3762/bjnano.6.94

• -deposited diffraction pattern exhibits broad diffraction rings characteristic of small grain size and possibly disorder due to high carbon content. The diffraction peaks narrow as grain size increases after curing. Grain coarsening is commonly associated with an increase in electrical conductivity of the

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• , lateral (in-plane) inhomogeneity and transverse gradient of disorder [3]. As far as disorder is concerned, in model systems made of linear alkyl chains tethered in a densely packed array, experiments and simulations indicate that a quasi-perfect order can be obtained (at least locally) at low temperature

• chain segments located away from the head towards the molecular tail. The strain-induced formation of gauche defects, initiating at outer bonds (end-gauche) and proceeding inward (kinks and gauche–gauche conformers) [3][17][22] results into a disorder gradient. Another important issue related to energy

• dissipation mechanisms is the behavior of tethered OML under compressive and shear forces, as found in nano-tribology experiments, where external forces can cause conformational changes. Again, a disorder gradient results from the formation of gauche defects which can be reverted when the atomic force

Influence of grain size and composition, topology and excess free volume on the deformation behavior of Cu–Zr nanoglasses

• Daniel Şopu and
• Karsten Albe

Beilstein J. Nanotechnol. 2015, 6, 537–545, doi:10.3762/bjnano.6.56

• interfaces don’t show topological disorder. Our results provide clear evidence that the mechanical properties of metallic NGs can be systematically tuned by controlling the size and the chemical composition of the glassy nanograins. Keywords: enhanced plasticity; metallic glasses; nanoglasses; shear bands

• deformation observed in the BMG. However, after a thermal annealing step, the excess free volume is equilibrating and only topological disorder can still be found in the glass–glass interfaces, which is having a minor influence on the formation of shear transformation zones. In the Zr-rich system (Cu36Zr64