Materials Literature
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The ground state energies of the group IB hexamer (Cu6, Ag6, and Au6) for four possible structural models, namely, 1A1 with a capped pentagonal structure (C5v), 1A1 with a tripyramidal structure (C2v), 1A1g with a circular ring structure (D6h), and 3T2g with an octahedral structure, as well as the positive ions, Cu+6,…
We present a detailed experimental study of the effects of finite crystal size, impurities, and temperature on the properties of charge-density waves (CDW's) in ${\mathrm{NbSe}}_{3}$. Finite-size effects in ${\mathrm{NbSe}}_{3}$ are controlled by the crystal thickness t. They are large in crystals of ordinary thicknes…
Flow microcalorimetry has been used to study microporous silicon produced by electrochemical corrosion of bulk p-type silicon wafers in highly concentrated (50 wt %) aqueous hydrofluoric acid. Calorimetry data on pore size and hydrophobicity of freshly etched crystalline silicon structures are compared with similar me…
In this work the optical properties of natural (IIa) and p-type semiconducting (IIb) diamonds were studied in the neighborhood of the first direct gap, at about 7 eV, whose energy position, nature, and origin are still under debate. The complex dielectric function \ensuremath{\epsilon}(\ensuremath{\omega}) of these ma…
The density of states of pregraphitic (disordered) carbon has been investigated using a tight-binding description of the electronic structure. The tight-binding Hamiltonian has been diagonalized using the recursion method for different stackings of graphene layers. The density of states of \ensuremath{\pi} electrons i…
The structure and dynamical properties of oxygen conductor yttria stabilized zirconia, (ZrO 2 ) 1- x (Y 2 O 3 ) x , are investigated for three dopant concentrations of 4.85, 10.2 and 22.7 mol%Y 2 O 3 using a method of molecular dynamics simulation. It is shown that a Y–O nearest neighbor distance is longer than that f…
A molecular dynamic computer simulation of the cooling of liquid silica to form an amorphous solid (glassy) phase was performed using the potential of Tsuneyuki, Tsukuda, Aoki, and Matsui, which was found to be consistent with the structure of several crystalline phases of silica. In the simulations, at low temperatur…
Abstract Interactions between cellulose and chitosan molecules in cellulose–chitosan blend films, prepared using trifluoroacetic acid as a cosolvent for the two polysaccharides, were studied by X‐ray diffraction and Raman analyses and by measurements of mechanical properties of the blend films. Crystallinity of cellul…
Abstract The effects of sodium alginate on the physical properties of fibroin membranes, such as rupture elongation, rupture strength, water absorption, and thermal properties, were investigated. The experimental results showed the β‐form crystal and β‐form molecular conformation increased due to the increase of inter…
The room temperature, photoluminescent properties of manganese-doped zinc sulfide films deposited by spray pyrolysis are reported. These films were deposited on Pyrex glass substrates at atmospheric pressure using air as a carrier gas. All films were polycrystalline with a wurtzite (hexagonal) structure. The manganese…
The deposition of thin Pb(ZrxTi1−x)O3 films by sol-gel and by metallo-organic decomposition (MOD) processes has been studied. Powders obtained from different precursor solutions were analyzed with respect to their decomposition and crystallization. Using a spin-coating technique, Pb(ZrxTi1−x)O3 films with zirconium co…
The electronic properties of simple hexagonal graphite have been studied in the framework of the density-functional technique, using nonlocal ionic pseudopotentials and a large number of plane waves. This work leads to a first-step qualitative understanding of the electronic properties of nonperiodic structures such a…
In the R${\mathrm{NiO}}_{3}$ series (R=La,Pr,Nd,Sm), the metal-insulator (M-I) transition temperature rises systematically as the size of the rare earth decreases and as the subsequent distortion from the ideal cubic perovskite increases. For R=La the system keeps its metallic character down to 1.5 K, while for R=Pr,…
The electronic structures of a wide range of transition-metal compounds, including Cu, Ni, Co, Fe, and Mn oxides and sulfides, with metal valences ranging from 2+ to 4+, have been investigated by a cluster-type configuration-interaction analysis of the core-level 2p x-ray photoemission spectra. We show that by includi…
The controlled-valence properties of ${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{FeO}}_{3}$ and ${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{MnO}}_{3}$ are studied by means of soft-x-ray absorption spectroscopy. A comparison bet…
Joint refinement of macromolecules against crystallographic and nuclear magnetic resonance (NMR) observations is presented as a way of combining experimental information from the two methods. The model of interleukin-1 beta derived by the joint x-ray and NMR refinement is shown to be consistent with the experimental o…
The effects of the cooling rate alpha and heating rate beta on trapping parameters and thermoluminescent (TL) glow peak intensities in LiF:Mg, Ti(TLD-100) crystals have been studied by glow curve fitting from room temperature to 500 K. It is found that under the investigated circumstances (1 K min -1 < alpha < 5000 K…
A theoretical model for porous structure formation during electrochemical anodization of aluminium is developed taking into account anodic oxide growth at the oxide/electrolyte and oxide/aluminium interfaces, electrochemical and field-enhanced oxide dissolution, and a three-dimensional configuration of electric field…
The fabrication of large area conducting polymer composities having prescribed polymer loadings and electrical properties has enabled them to be characterised over the frequency range 2–18 GHz using a free-space reflectivity arch and an HP 8510B network analyser. Representative examples of practical narrow- and broadb…
Abstract Twenty differently substituted 2,2′,2″,2‴ ‐[(2,2′‐bipyridine‐6,6′‐diyl)bis(methylenenitrilo)]tetrakis(acetc acids) 75–94 were synthesized with the purpose of developing new markers to be used in bioaffinity assays based on the unique luminescence properties of Eu III and Tb III ions. The relative luminescence…