Materials Literature
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Single-walled carbon nanotube field-effect transistors were fabricated using solid electrolyte (PEO plus LiClO 4 ) as gating materials. The SWNT FETs demonstrated strong gate-channel coupling with improved device characteristics compared with back-gated devices. More importantly, the nanotubes can be easily doped usin…
The characteristics of an imaging system formed by a left-handed material (LHM) slab of finite length are studied, and the influence of the finite length of the slab on the image quality is analyzed. Unusual phenomena such as surface bright spots and negative energy stream at the image side are observed and explained…
A quantum-mechanical simulation is carried out to investigate the charge distribution and electrostatic potential along a 1 microm long (5,5) single-walled carbon nanotube under realistic field-emission experimental conditions. A single layer of carbon atoms is found sufficient to shield most of the electric field exc…
The novel dimeric germanotungstates [M(4)(H(2)O)(2)(GeW(9)O(34))(2)](12)(-) (M = Mn(2+), Cu(2+), Zn(2+), Cd(2+)) have been synthesized and characterized by IR spectroscopy, elemental analysis, magnetic measurements, and (183)W-NMR spectroscopy. X-ray single-crystal analyses were carried out on Na(12)[Mn(4)(H(2)O)(2)(G…
We have performed systematic calculations for single vacancies and their related point defects in achiral carbon nanotubes using a tight-binding model. Our calculations clarify that the local structures around single vacancies in such tubes do reconstruct with no constraint. We find that the structural configuration a…
Certain DNA sequences form a highly stable monolayer at the surface of single-walled carbon nanotubes, enabling their dispersion in aqueous solution. Ion-exchange chromatography can be used to separate these systems on the basis of their diameter in distinct, eluted fractions. Raman and fluorescence spectroscopy are u…
We demonstrate electroluminescence (EL) with an external efficiency of more than 0.1% at room temperature from glide dislocations in silicon. The key to this achievement is a considerable reduction of nonradiative carrier recombination at dislocations due to impurities and core defects by impurity gettering and hydrog…
Semiconductor dopant profiling using secondary electron imaging in a scanning electron microscope has been developed in recent years. In this letter, we show that the mechanism behind it also allows mapping of the electric potential of undoped regions. By using an unbiased GaAs/AlGaAs heterostructure, this letter demo…
Hydrogen single-particle dynamics in solid LiH at T=20 K has been studied through the incoherent inelastic neutron scattering technique. A careful analysis of the scattering data has allowed for the determination of a reliable hydrogen-projected density of phonon states and, from this, of three relevant physical quant…
We present a neutron scattering analysis of the density and the static structure factor of confined methanol at various temperatures. Confinement is performed in the cylindrical pores of MCM-41 silicates with pore diameters D=24 angstrom and D=35 angstrom. A change of the thermal expansivity of confined methanol at lo…
Magnetic, transport and x-ray diffraction measurements of the ferromagnetic shape memory alloy Ni 2.16 Mn 0.84 Ga have revealed that this alloy undergoes an intermartensitic transition upon cooling, whereas no such a transition is observed upon subsequent heating. The difference in the modulation of the martensite for…
Au nanoparticles exhibit ferromagnetic spin polarization and show diameter dependence in magnetization. The magnetic moment per Au atom in the particle attains its maximum value at a diameter of about 3 nanometer (nm) in the Magnetization-Diameter curve. Because Au metal is a typical diamagnetic material, its ferromag…
A novel starlike polyfluorene derivative, PFO-SQ, was synthesized by the Ni(0)-catalyzed reaction of octa(2-(4-bromophenyl)ethyl)octasilsesquioxane ( OBPE - SQ ) and polydioctylfluoroene ( PFO ). The incorporation of the silsesquioxane core into polyfluorene could significantly reduce the aggregation as well as enhanc…
In order to investigate the coexistence of magnetism and superconductivity on a microscopic scale, local studies using zero-field spin-echo ^{99,101}Ru NMR and ^{63,65}Cu NQR have been carried out on both superconducting and non-superconducting samples of magnetically ordered RuSr_{2}EuCu_{2}O_{8} and RuSr_{2}GdCu_{2}…
We validate that off-resonant electron transport across {\it ultra-short} oligomer molecular junctions is characterised by a conductance which decays exponentially with length, and we discuss a method to determine the damping factor via the energy spectrum of a periodic structure as a function of complex wavevector. A…
A monoethylaluminum Schiff base complex (2) with formula LAlEt (L = N,N'-(2,2-dimethylpropylene)bis(3,5-di-tert-butylsalicylideneimine) was synthesized and employed for the stereoselective ring-opening polymerization of rac-lactide (rac-LA). The complex 2 was characterized by nuclear magnetic resonance, crystal struct…
Marine benthic diatoms excrete large quantities of extracellular polymeric substances (EPS), both as a function of their motility system and as a response to environmental conditions. Diatom EPS consists predominantly of carbohydrate‐rich polymers and is important in the ecology of cells living on marine sediments. Pr…
Raman spectra of ZnO powder and free-standing nanowires prepared by laser ablation have been studied. All observed vibrational modes in ZnO powder, both first order and higher order scattering, were assigned on the basis of group theoretical analysis. The size dependence of the coupling strength between electron and l…
Single walled carbon nanotubes with Pd Ohmic contacts and lengths ranging from several microns down to 10 nm are investigated by electron transport experiments and theory. The mean-free path (MFP) for acoustic phonon scattering is estimated to be l(ap) approximately 300 nm, and that for optical phonon scattering is l(…
Carbon nanotubes are exceptionally interesting from a fundamental research point of view. Many concepts of one-dimensional physics have been verified experimentally such as electron and phonon confinement or the one-dimensional singularities in the density of states; other 1D signatures are still under debate, such as…