Materials Literature
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The core-level x-ray photoemission spectroscopy (XPS) satellites of single-crystalline ${\mathrm{SrTiO}}_{3},$ ${\mathrm{SrTiO}}_{3}:\mathrm{La},$ and ${\mathrm{SrTiO}}_{3}:\mathrm{Nb}$ in situ fractured in ultrahigh vacuum were compared with the electron-energy-loss spectrum and theoretical electron-energy-loss funct…
A family of crystal structures of carbon composed of alternating ${\mathrm{sp}}^{2}$ and ${\mathrm{sp}}^{3}$ bonds is investigated. Graphitic strips are connected by ${\mathrm{sp}}^{3}$ bonds to form an array of hexagonal pillars exhibiting a honeycomb lattice in the perpendicular plane. The electronic structure and e…
This paper considers the effects of a realistic description of phonons in diamondlike semiconductors and their conversion on the abrupt heterointerfaces on the thermal conductivity of the superlattice (SL). Due to the much larger mass of Ge atoms in comparison to Si, the most probable acoustic phonons in Si layers at…
We study the effective interactions, structure, and the isothermal compressibility of a binary mixture interacting with pairwise additive pair potentials. By integrating out the degrees of freedom of species 2 in the partition sum we first show that a binary mixture can be mapped formally onto an effective one-compone…
The spin configuration of isoelectronic vacancies surrounded by first-row atoms is studied within density-functional theory (DFT) using the local spin density approximation. Allowing for a symmetry break in the electronic system, a mixed-spin state is found to be lowest in energy. It is accompanied by a magnetization…
High-resolution Compton scattering measurements on Be single crystals along three main crystallographic directions ([10\ensuremath{\cdot}0], [11\ensuremath{\cdot}0], and [00\ensuremath{\cdot}1]) have been carried out using incident photon energies of 10, 29, and 56 keV to study the energy dependence of the scattering…
We have calculated the electronic structure of spherical PbS, PbSe, and PbTe quantum dots using a four-band envelope-function formalism that accounts for band anisotropy. By comparing our results with an analytical calculation that assumes a spherical approximation of the $\stackrel{\ensuremath{\rightarrow}}{k}\ensure…
Core-level photoemission spectra of graphite have been measured at very high resolution. The C $1s$ level is found to have a lifetime width with an upper limit of $165\ifmmode\pm\else\textpm\fi{}15\mathrm{meV},$ which is considerably narrower than previously reported. The width is still substantially larger than that…
Polyimide was irradiated with a XeCl excimer laser (308 nm) and the ablated area and its surrounding were studied using transmission electron microscopy (TEM) and confocal Raman microscopy. Ring-like structures surrounding the ablated area were detected at all fluences. At fluences lower than 250 mJ/cm−2 the formation…
The present article deals with the development of a new statistical model (corrugated pore structure model: CPSM) simulating capillary condensation−evaporation hysteresis. The formulation of analytical expressions is based on probability principles, an adsorbed layer thickness correlation, Kelvin equation, and a rando…
Catalytically grown carbon nanofibers are a set of novel structures that are produced by the decomposition of selected carbon-containing gases over metal particles. These conformations consist of nanosized graphite platelets separated a distance of at least 0.34 nm and stacked in various orientations with respect to t…
The synthesis and characterization of dye loaded zeolite L sandwiches acting as artificial antenna systems for light harvesting and transport is reported. A set of experimental tools for the preparation of neutral dye-zeolite L materials ranging from low to maximum packing densities has been developed. The role of co-…
Energetics and electronic states of ${\mathrm{Si}}_{34\ensuremath{-}x}{\mathrm{Ge}}_{x}$ clathrate alloys have been investigated. The atomistic structures, the equations of state, and the lineup of band structures for these clathrates are calculated using the Vanderbilt ultra-soft pseudopotential method within the loc…
The first nuclear magnetic resonance (NMR) evidence of charge ordering in a quasi-two-dimensional organic conductor is presented. We have performed ${}^{13}\mathrm{C}$ NMR shift and relaxation rate measurements for the organic conductor, $\ensuremath{\theta}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}…
The components that contribute to Raman spectral shifts of single-wall carbon nanotubes (SWNT's) embedded in polymer systems have been identified. The temperature dependence of the Raman shift can be separated into the temperature dependence of the nanotubes, the cohesive energy density of the polymer, and the buildup…
The synthesis of high-nuclearity metal-cyanide clusters presents a possible means of controlling magnetic properties in the design of new single-molecule magnets. Previous work employed tridentate blocking ligands in directing the assembly of a cubic [(tacn) 8 Co 8 (CN) 12 ] 12+ (tacn = 1,4,7-triazacyclononane) cluste…
In the field of micelle templated structures (MTS), the MSU-X family of mesoporous silica is obtained by using nonionic poly(ethylene oxide)-based surfactants. We show that the microstructure of these materials is highly dependent on the initial pH conditions and that a first assembly step, using a mild acidity, which…
Annealing of amorphous ${\mathrm{S}\mathrm{i}/\mathrm{S}\mathrm{i}\mathrm{O}}_{2}$ or ${\mathrm{G}\mathrm{e}/\mathrm{S}\mathrm{i}\mathrm{O}}_{2}$ multilayers produces nanocrystals embedded between oxide interfaces. It is found that the crystallization temperature is strongly enhanced by the presence of the oxide inter…
We have computed first-principles occupied Wannier-like functions within an unprecedented spatial range in a realistic model of amorphous Si containing 4096 atoms. To avoid the computation of eigenstates we applied the $O(N)$ Fermi-operator expansion method. The functions decay exponentially in space in a fashion simi…
CaS:Eu 2+ ,Tm 3+ is a persistent red phosphor. Thermoluminescence was measured under different excitation and thermal treatment conditions. The results reveal that the charge defects, created by substituting Tm3+ for Ca2+, serve as hole traps for the afterglow at room temperature. Tm3+ plays the role of deep electron…