Materials Literature
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This paper reports the results of experimental studies of the dynamics of particles in a dense quasi-two-dimensional colloidal liquid. We find that at high density, near close packing but still in the liquid phase, the spatial configurations of the particles in the colloidal liquid consist of small ordered domains sep…
We study the transmission properties of light through the symmetric Fibonacci-class $[\mathrm{SFC}(n)]$ quasiperiodic dielectric multilayers, which possess a mirror symmetry. For a normal incidence of light, many perfect transmission peaks (the transmission coefficients are unity) are numerically obtained. The transmi…
Field electron emission properties of aligned multi-walled carbon nanotube films were studied with variation of the vacuum gap d between anode and cathode. With d varying in the range of 0.4-2 mm, the emission current-gap voltage characteristics and the corresponding Fowler-Nordheim (FN) plots show distinct nonlineari…
We report on the first chemically prepared multilayer quantum well structure in a semiconductor quantum dot. By subsequent precipitation of HgS, CdS, HgS, and again CdS from aqueous solution, we obtained nanoparticles which contain two HgS quantum wells separated by a double layer of CdS. The core and the capping mate…
The crystal structure of anthranilate synthase (AS) from Serratia marcescens, a mesophilic bacterium, has been solved in the presence of its substrates, chorismate and glutamine, and one product, glutamate, at 1.95 A, and with its bound feedback inhibitor, tryptophan, at 2.4 A. In comparison with the AS structure from…
JANA is a computer program for the refinement and analysis of periodic and aperiodic (incommensurately modulated structures and composite crystals) crystal structures. Here a new module is introduced that allows Rietveld refinements against powder diffraction data. It is shown that JANA 2000 provides a state-of-the-ar…
Quantitative determination of phase abundance in a multicomponent polycrystalline mixture is a basic goal in materials characterization. Because of several advantages compared with traditional techniques, the Rietveld method has been increasingly applied to this task. Further progress in this direction would be to car…
The spin-crossover iron(II) complex [Fe(L)(CN)2]·H2O (1) has been investigated. Complex 1 has a pentagonal bipyramidal structure which is seven-coordinated, containing an N3O2 macrocycle and two CN- ligands. Water molecules bind the complex by means of hydrogen bonding. It was found that the complex 1 exhibited a ligh…
The positions of Bragg edges in neutron transmission experiments can be defined with high accuracy using the time-of-flight (TOF) technique on pulsed neutron sources. A new dedicated transmission instrument has been developed at ISIS, the UK spallation source, which provides a precision of Δ d / d ≃ 10 −5 in the deter…
Fundamental aspects of the cooperative Jahn-Teller effect are investigated using density functional theory in the generalized gradient approximation. ${\mathrm{LiNiO}}_{2},$ ${\mathrm{LiMnO}}_{2},$ and ${\mathrm{LiCuO}}_{2}$ are chosen as candidate materials as they possess small, intermediate, and large cooperative J…
At a given temperature, clean and adatom covered silicon surfaces usually exhibit well-defined reconstruction patterns. Our finite temperature ab-initio molecular dynamics calculations show that the tellurium covered Si(001) surface is an exception. Soft longitudinal modes of surface phonons due to the strongly anharm…
Optical-absorption cross-sections and energy-loss spectra of aligned multishell carbon nanotubes are investigated, on the basis of photonic band-structure calculations. A local graphite-like dielectric tensor is assigned to every point of the tubules, and the effective transverse dielectric function of the composite i…
Results from an extensive single-crystal neutron-scattering study of the relaxor ferroelectric $\mathrm{Pb}({\mathrm{Zn}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}$ (PZN) in the cubic phase reveal an anomalous ridge of inelastic scattering that extends vertically from the transverse acoustic (TA) branch near 4 meV to…
This Letter describes the first real space observation for the formation of a house of cards structure in polypropylene/clay nanocomposite melt under elongational flow by TEM analysis. Both strong strain-induced hardening and rheopexy features are originated from the perpendicular alignment of the silicate layers to t…
Two different methods of diffraction profile analysis are presented. In the first, the breadths and the first few Fourier coefficients of diffraction profiles are analysed by modified Williamson–Hall and Warren–Averbach procedures. A simple and pragmatic method is suggested to determine the crystallite size distributi…
A Reply to the Comment by S. L. Chaplot and R. Mittal.Received 26 July 2000DOI:https://doi.org/10.1103/PhysRevLett.86.4977©2001 American Physical Society
The dislocation densities and arrangement parameters and the crystallite size and size-distributions are determined in tensile or cyclically deformed polycrystalline copper specimens by X-ray diffraction peak profile analysis. The Fourier coefficients of profiles measured by a special high resolution X-ray diffractome…
We study the effect of wavelength on the laser-induced phase transformation in semiconductor quantum dots. In our earlier report [Yakovlev et al., Appl. Phys. Lett. 76, 2050 (2000)], we discovered that a nanosecond pulse of 532 nm radiation results in a phase transformation of CdS nanocrystals from an orthorhombic to…
Gallium arsenide (GaAs) crystalline nanorods were grown by molecular-beam epitaxy (MBE). Scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray fluorescence measurements showed that the grown GaAs nanorods were straight single crystals with diameters between 70 and 80 nm, lengths o…
We report on a metastable light-induced volume expansion in ${\mathrm{Ge}}_{25+x}{\mathrm{Ga}}_{10\ensuremath{-}x}{\mathrm{S}}_{65}$ glasses under irradiation with band gap (UV) light, which can result in recording of relief gratings on their surface in the case of irradiation with two interfering beams. We propose a…