Materials Literature
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The crystal structures of a few phases of Ti such as hcp, bcc, $\ensuremath{\omega}$ (hexagonal phase) $\ensuremath{\gamma}$ (distorted hcp), $\ensuremath{\delta}$ (distorted bcc), and bcc under pressure have been studied by means of first-principles total-energy calculations in a generalized gradient approximation. O…
The line shape and intensity of surface and bulk plasmon excitations in Al $2s$ and $2p$ core-level spectra of Al(111) have been studied as functions of the photoelectron emission angle (\ensuremath{\theta}). For both surface and bulk plasmons, an asymmetric line shape is observed in normal emission, which becomes mor…
The paper presents a general formalism for the $n\mathrm{t}\mathrm{h}\ensuremath{-}\mathrm{n}\mathrm{e}\mathrm{a}\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{t}\ensuremath{-}\mathrm{n}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{b}\mathrm{o}\mathrm{r}\phantom{\rule{0ex}{0ex}}\mathrm{d}\mathrm{i}\mathrm{s}\mathrm{t}\mathrm…
The optical properties of Ge and Si nanocrystals embedded in a crystalline matrix are calculated using an ab initio supercell method. Spectra of effective nanocrystallite materials including confinement effects are extracted by means of effective-medium theory. Spectra for different composites are calculated and compa…
Green ${\mathrm{Tb}}^{3+}{}^{5}{\stackrel{\ensuremath{\rightarrow}}{{\mathrm{D}}_{4}}}^{7}{\mathrm{F}}_{\mathrm{J}\mathrm{}}$ luminescence visible by eye is observed under near-infrared laser excitation. Optical spectroscopic techniques including absorption, luminescence, and excitation spectroscopy are used to charac…
The Gibbs-Bogolyubov inequality is used to establish a mapping between the Yukawa system and both the hard-sphere and the one-component reference systems. The transport coefficients of self-diffusion, shear viscosity, and thermal conductivity are computed for the Yukawa fluid using known properties of the reference sy…
The experimental magnetic susceptibility and heat capacity of ${\mathrm{LaCoO}}_{3}$ due to spin-state excitation in the range 2--300 K were well reproduced by a one-lattice molecular-field model with negative cooperative effect; an energy separation between the low-spin ground state and the excited state increases wh…
We have investigated the influence of post-deposition annealing on the optical and electrical properties of c -axis oriented zinc oxide films prepared on sapphire substrates by electron beam evaporation. The ZnO films as-deposited and annealed in air were colourless and transparent in visible range and had sharp ultra…
Abstract The Michael reaction of chitosan with acrylic acid was carried out successfully, even in water alone as the reaction medium. As a consequence of its good solubility in water, the reaction product, N ‐carboxyethylchitosan, showed excellent biodegradable properties with standard activated sludge. magnified image
The $2n+1$ theorem and the density-functional perturbation theory have been used to calculate anharmonic force constants completely ab initio. Explicit expressions for the anharmonic coupling constants are presented, i.e., for the third-order derivatives of the total energy with respect to atomic displacements. Using…
Persistent currents in rings constructed from carbon nanotubes are investigated theoretically. After studying the contribution of finite temperature or quenched disorder on covalent rings, the complexity due to the bundle packing is addressed. The case of interacting nanotori and self-interacting coiled nanotubes are…
Abstract Via a batch process in an autoclave, the foam processing of neat polylactide (PLA) and two different types of PLA/layered silicate nanocomposites has been conducted using supercritical carbon dioxide as a foaming agent. The morphological correlation between the dispersed silicate particles with nanometer dime…
The present communication is a critical examination of two points relevant to the surface phase transitions of Pb and Sn overlayers on Ge(111). One is connected with the reading of the reported structural data, which lead to some consequences of paramount importance but overlooked up to now. The other point is the see…
Scanning Tunnelling Spectroscopy of GaAs(110):Au Schottky contacts in cross-sectional configuration has been used to investigate the in-depth properties of the space charge layer as well as the interface region with nanometer resolution.
Monodispersed spherical cadmium sulfide particles were used as a model system in order to explain the size selection in the formation of colloids by aggregation of nanosize subunits. Several procedures of mixing the reactants were employed to precipitate these solids and follow the kinetics of particle growth. Efficie…
The ability to predict particle morphology (shape) in the presence of habit-modifying impurities is of great use in allowing the optimization of growth conditions to produce a required crystal habit. Previous morphological modeling techniques developed by the authors 1,2 utilized the attachment energy method, which as…
The development of novel cyclotriphosphazene and oligoethyleneoxy-functionalized poly(7-oxanorbornenes) for possible use as solid polymer electrolytes in the electrolyte layer of rechargeable lithium batteries is described. The length of the oligoethyleneoxy group on the cyclotriphosphazene has been varied, and the ef…
We report the results of density functional theory (DFT) calculations of the 57 Fe Mössbauer quadrupole splittings Δ E Q and isomer shifts δ Fe of both the high-spin (HS) and low-spin (LS) states of two typical spin crossover complexes: the six-coordinate species cis -bis(thiocyanato)bis(1,10-phenanthroline)iron(II),…
A macroporous perovskite manganite, La0.7Ca0.3MnO3, exhibits a three-dimensionally ordered ferromagnetic network that is replicated from a colloidal polymer template. The spherical voids are interconnected via small channels.
Microcrystals of an organic fluorescent dye, 4-n-octylamino-7-nitrobenz-2-oxa-1,3-diazole (NBD-C8), were prepared by reprecipitation in water. The crystallization kinetics was monitored by UV/vis absorption spectroscopy, and a model was proposed. The size and shape of the microcrystals were analyzed by laser light sca…