Materials Literature
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CdS thin films are grown by photochemical deposition from an aqueous solution and characterized by x-ray diffraction (XRD), Raman spectroscopy, photoluminescence measurement, and optical transmission spectroscopy. The films are deposited at room temperature and annealed at temperatures up to 500 °C. The as-deposited f…
The local orbital extension of the linearized augmented plane wave (LAPW+LO) method within the general gradient approximation was used to determine structural and ferroelectric properties of tetragonal ${\mathrm{PbTiO}}_{3}$ (PT), and two chemically ordered ${\mathrm{PbZr}}_{1/2}{\mathrm{Ti}}_{1/2}{\mathrm{O}}_{3}$ (P…
Based on ab initio calculations of electronic structure and properties of five crystals: $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Al}}_{2}{\mathrm{O}}_{3},$ ${\mathrm{Y}}_{3}{\mathrm{Al}}_{5}{\mathrm{O}}_{12},$ ${\mathrm{YAlO}}_{3},$ ${\mathrm{Y}}_{4}{\mathrm{Al}}_{2}{\mathrm{O}}_{9},$ ${\mathrm{Y}}_{2}{\mathrm{O}}_…
Band structure of the ferrimagnetic Fe 3 O 4 was calculated in the high temperature cubic phase by means of the full-potential linearized augmented-plane-wave method with the local spin density approximation. In the majority spin bands, the Fermi level stays in the band gap and 3d states of A site Fe are unoccupied wh…
Artificial atoms, i.e., systems of excess electrons confined in semiconductor quantum dots, are studied by the unrestricted Hartree-Fock method. We consider a spherical quantum dot embedded in an insulating matrix and assume a confinement potential in a form of spherical potential well of radius R and depth ${V}_{0}.$…
In this paper we describe collective properties of silver nanoparticles organized in two-dimensional superlattices. Our aim is to show that we can control the state of organization of the silver particles deposited on the substrate. Then the particles are found in the form of either a well-organized two-dimensional ar…
Amorphous and nanostructured carbon films were grown by using two different techniques: ion sputtering and cluster beam deposition. The films were studied by near-edge x-ray absorption fine structure (NEXAFS) and Raman spectroscopy. Depending on the precursors, atoms, or clusters, the films are characterized by a diff…
Powder neutron diffraction has been used to study the nature of the structural transition away from the Fd 3 m cubic structure upon cooling below ∼285 K in the spinel LiMn 2 O 4 . We report powder data taken between 10 K and 333 K and propose a large cell tetragonal structure in space group I 4 1 / amd for the materia…
Pyroelectric lead zirconate titanate (PZT) thin films have been prepared by a sol-gel method and characterized by x-ray diffraction and transmission electron microscopy (TEM). A metastable Pt3Pb intermetallic phase has been identified. The formation of this metastable phase was found to depend on the drying temperatur…
The $s,p\ensuremath{-}d$ exchange interaction of p-type ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As} (x<0.05)$ epilayers is investigated by means of magnetoabsorption. The observed ferromagnetic-type splitting of fundamental absorption edge is explained by antiferromagnetic $p\ensuremath{-}d$ excha…
The dielectric and insulating properties of epitaxial SrTiO3(STO) thin film capacitors were studied. The films were grown by inverted cylindrical magnetron sputtering in the radio frequency mode on (100) STO substrates which were covered with a (001)-oriented YBa2Cu3O7−x (YBCO) layer as a ground electrode. As a top el…
Efficient quenching of Ru(bpy)(3)(2+) (bpy = 2,2'-bipyridine) electrogenerated chemiluminescence has been observed in the presence of phenols, catechols, hydroquinones, and benzoquinones. In most instances, quenching is observed with 100-fold excess of quencher over Ru(bpy)(3)(2+), with complete quenching observed bet…
Diamond samples doped with phosphorus either during high-pressure/high-temperature synthesis or during chemical vapor deposition growth are studied by cathodoluminescence at low temperatures. Some of the specimens unintentionally contain boron acceptors in low concentrations as demonstrated by the observation of boron…
We study the energetics of island formation in Stranski-Krastanow growth within a parameter-free approach. It is shown that an optimum island size exists for a given coverage and island density if changes in the wetting layer morphology after the 3D transition are properly taken into account. Our approach reproduces w…
We report here measurements of the thermoelectric power and longitudinal magneto-Seebeck coefficient of 200 nm diameter single-crystal bismuth nanowires. Nanowires of pure Bi and of n-type-doped Bi (with Te at about $5\ifmmode\times\else\texttimes\fi{}{10}^{18}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}3})$ were measured.…
In this article, we reexamine and extend a relationship proposed earlier between entanglement density and chain dimensions in polymer melts. The power-law equation presented in the earlier work, relating the entanglement molecular weight Me, melt chain density ρ, and the packing length p is tested with additional poly…
A melt of linear diblock copolymers (AnBm) can form a diverse range of microphase separated structures. The detailed morphology of the microstructure depends on the length of the polymer blocks An and Bm and their mutual solubility. In this paper, the role of hydrodynamic forces in microphase formation is studied. The…
A comprehensive study of the stress release and structural changes caused by postdeposition thermal annealing of tetrahedral amorphous carbon (ta-C) on Si has been carried out. Complete stress relief occurs at 600–700 °C and is accompanied by minimal structural modifications, as indicated by electron energy loss spect…
A study based on ab initio calculations is presented on the structural, elastic, and vibrational properties of single-wall carbon nanotubes with different radii and chiralities. These properties are obtained using an implementation of pseudopotential-density-functional theory, which allows calculations on systems with…
Free energy was measured for the surface of regular aligned closest hexagonal packed −CF 3 groups. n -Perfluoroeicosane was vapor deposited onto glass, which gave epitaxially grown single-like crystallites with their molecular axes perpendicular to the glass surface. The dynamic contact angle of water on its surface w…