Materials Literature
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The 1∕f noise in individual semiconducting carbon nanotubes (s-CNT) in a field effect transistor configuration has been measured in ultrahigh vacuum and following exposure to air. The amplitude of the normalized current spectral noise density is independent of source-drain current and inversely proportional to gate vo…
Various mechanisms for the growth and renucleation of ultrananocrystalline diamond (UNCD) films are discussed and evaluated in the light of experimental and theoretical evidences in recent publications. We propose that the most likely model for UNCD growth is that where most of the diamond is formed via a similar mech…
A mechanism is described whereby 180° domain wall motion can contribute to the electrically induced strain in a ferroelectric material at subcoercive ac electric fields. The field-dependent, largely reversible motion of ferroelectric, 180° domain walls due to an applied ac electric field is considered. The Rayleigh la…
This letter reports a novel deformation mechanism of twinned Cu nanowires, based on molecular statics and dynamics simulations. Under mechanical loading, Shockley partial dislocations nucleate and glide on a {111} plane toward a twin boundary. Upon penetration of the twin boundary, a dislocation with Burgers vector of…
Solid films of CdSe colloidal quantum dots are conductive when reduced by electrochemistry. The dark conductivity and the photoconductivity of these n-type CdSe nanocrystalline solids have been investigated as a function of film treatment. When the films are treated with NaOH, a carrier mobility of ∼10−2cm2∕Vs and a c…
Structural and mechanical properties of amorphous and nanocomposite carbon are investigated using tight-binding molecular dynamics and Monte Carlo simulations. In the case of amorphous carbon, we show that the variation of sp^3 fraction as a function of density is linear over the whole range of possible densities, and…
The room-temperature crystal structures of six A(2)M(3+)M(5+)O(6) ordered perovskites have been determined from neutron and X-ray powder diffraction data. Ba(2)YNbO(6) adopts the aristotype high-symmetry cubic structure (space group Fm\overline 3m, Z = 4). The symmetries of the remaining five compounds were lowered by…
Interpolating scaling functions give a faithful representation of a localized charge distribution by its values on a grid. For such charge distributions, using a Fast Fourier method, we obtain highly accurate electrostatic potentials for free boundary conditions at the cost of O(N log N) operations, where N is the num…
We analyze the Blume-Emery-Griffiths model with disordered magnetic interaction displaying the inverse freezing phenomenon. The behaviour of this spin-1 model in crystal field is studied throughout the phase diagram and the transition and spinodal lines for the model are computed using the Full Replica Symmetry Breaki…
Using numerical and analytical micromagnetics we calculated the switching fields and energy barriers of the composite (exchange spring) magnetic recording media, which consist of layers with high and low magnetocrystalline anisotropy. We demonstrate that the ultimate potential of the composite media is realized if the…
A simple fabrication technique for subwavelength structured (SWS) surfaces by means of anodic porous alumina masks directly formed on Si substrates was proposed and demonstrated. By this technique, SWS surfaces were fabricated on polished single-crystalline Si and chemically etched as-cut multicrystalline Si wafers. S…
Self-organized porous structures of WO3 were grown on tungsten by an anodic oxidation, and their photoelectrochemical properties were characterized. The porous WO3 layers show a regular morphology with average pore sizes of approximately 70nm and a pore wall thickness of approximately 10nm. As formed layers show an am…
ZnO nanowire-array-embedded n-ZnO∕p-GaN heterojunction light-emitting diodes were fabricated by growing Mg-doped p-GaN films, ZnO nanowire arrays, and polycrystalline n-ZnO films consecutively. Electroluminescence emission having the wavelength of 386nm was observed under forward bias in the heterojunction diodes and…
We present the theory of orbital ordering in orbital-degenerate itinerant electron systems. After proposing the criterion of instability for orbital ordering or orbital density wave ordering, we find that the orbital and the spin-orbital collective excitation spectra in ferro-orbital ordered phase exhibit finite gaps.…
The self-diffusion coefficient of zinc in ZnO is derived as a function of the chemical potential and Fermi level from first-principles calculations. Density functional calculations in combination with the climbing image-nudged elastic band method are used in order to determine migration barriers for vacancy, interstit…
p -type ZnO films have been fabricated on a (0001) Al2O3 substrate, using Ag2O as a silver dopant by pulsed laser deposition. The structural property of those films is systematically characterized by observing the shift of (0002) peak to investigate the substitution of Ag+ for Zn+. Narrow deposition temperature for Ag…
We present a wet chemical process for nanoscale texturing of Si surfaces, which results in an almost complete suppression of the reflectivity in a broad spectral range, leading to black Si surfaces. The process affects only the topmost 200–300nm of the material and is independent of the surface orientation and doping.…
Density-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite-size effects and the improper description of the band structure. The generalized gradient approximation (GGA) with empirical self-interaction corrections $(\mathrm{G…
The magnetic and structural transformations in the Heusler-based system ${\mathrm{Ni}}_{0.50}{\mathrm{Mn}}_{0.50\ensuremath{-}x}{\mathrm{In}}_{x}$ are studied in the composition range $0.05\ensuremath{\leqslant}x\ensuremath{\leqslant}0.25$. While the cubic phase is preserved in the range $0.165\ensuremath{\leqslant}x\…
The mechanism for fumarate reduction by the soluble fumarate reductase from Shewanella frigidimarina involves hydride transfer from FAD and proton transfer from the active-site acid, Arg-402. It has been proposed that Arg-402 forms part of a proton transfer pathway that also involves Glu-378 and Arg-381 but, unusually…