Materials Literature
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The deuteration of oxygen adatoms on the Ru(001) surface has been investigated by means of temperature programmed desorption and high-resolution electron energy loss spectroscopy. Exposure of gas-phase atomic deuterium to the p(1×2) oxygen overlayer with a fractional adatom coverage of oxygen of 0.5 leads to the produ…
We made measurements of dielectric constant, pyroelectric current, magnetic susceptibility and magnetoelectric effect of single crystals of YbMn 2 O 5 . From the results, we concluded that there were two phase transitions besides antiferromagnetic transition at approximately 40 K. The first transition at 32 K is chara…
Colossal magnetoresistance (CMR) properties have been evidenced for the manganese perovskites La0.7−xYxCa0.3MnO3−δ with 0.01≤x≤0.20. This system is compared to the manganites Pr0.7Ca0.3−xSrxMnO3−δ that exhibit the same Mn(III)/Mn(IV) ratio. Like for this second system, one observes that the transition temperature T1 i…
The ground and excited state properties of the Cr3+ ion doped into the cubic host lattices Cs2NaYCl6 and Cs2NaYBr6 have been studied using density functional theory. A new symmetry based technique was employed to calculate the energies of the multiplets 4A2g, 4T2g, 2Eg, and 4T1g. The geometry of the CrX3−6 cluster was…
A systematic study of porous silicon anodic oxidation is reported. We have studied the evolution of the lattice parameter versus oxidation levels for p- and p+-type materials by using high-resolution x-ray diffraction, which gives a determination of the strains of the porous layer. The analysis of an asymmetric reflec…
Laser deposition technique has been applied to synthesize (Sr0.2Ba0.8)TiO3 thin films. The crystal structure of the films and the effect of deposition parameters on them have been systematically examined. Among the important deposition parameters, the substrate temperature and the chamber oxygen pressure affect the ch…
Small-angle x-ray scattering (SAXS) from single-phase melts and solutions of polystyrene-block-polyisoprene (SI) having various degrees of polymerization N and compositions f were analyzed on the basis of Landau-type mean-field theory developed by Leibler. The effective Flory interaction parameter χeff per segment in…
As an effective model to describe perovskite-type manganates (La,$A$)MnO$_3$, the double-exchange model on a cubic lattice is investigated. Spin excitation spectrum of the model in the ground state is studied using the spin wave approximation. Spin wave dispersion relation observed in the inelastic neutron scattering…
The reaction of excess trimethylgallium with acridine in diethyl ether gave the title layer inclusion compound, [Ga(CH 3 ) 3 (C 13 H 9 N)].0.5C 13 H 9 N. The Ga-N bond length is 2.203 (3) A.
Iron carbonitride (ICN) ultrafine particles (20–80 nm in size) have been synthesized by laser-induced pyrolysis of Fe(CO)5–NH3–C2H4 mixture. The surface morphology, structural characteristics, oxidation behavior, and the magnetic properties of the ICN particles were reported. The role the thin carbon layer formed on t…
The title compound, caesium lanthanum diniobium heptaoxide, belongs to the ARNb2O7 (A = K, Rb, Cs; R = La, Nd) family of compounds and crystallizes as a layered structure in which the Cs+ ions are located in the interlayer gap formed by double perovskite LaNb2O7 layers. The single-crystal X-ray refinement of the struc…
We present the results of a theoretical investigation of the electromigration wind force for adatom migration in a number of migrator-substrate systems. The theoretical background for our study follows from previous work done on bulk electromigration using the linear-response formalism of Kubo. We treat the electronic…
The origin of the cracking of highly porous silicon layers during drying is investigated. Optical and scanning electron microscopy observation allow us to observe the cracking occurrence. In situ x-ray diffraction experiments, under controlled vapor pressure of pentane, reveal that large capillary stresses occur at a…
The adsorption and temperature-dependent decomposition of ${\mathrm{SO}}_{2}$ on Cu(100) and Cu(111) have been studied by fast and high-resolution core-level photoemission. The analysis of the S 2p and O 1s data shows that molecular ${\mathrm{SO}}_{2}$ adsorption dominates at 170 K. On heating the ${\mathrm{SO}}_{2}$-…
We present converged first-principles calculations for the atomic and electronic structure of diamond (111) surfaces based on density-functional theory in the local-density approximation. Single- and triple-dangling- bond surfaces with 1\ifmmode\times\else\texttimes\fi{}1, 2\ifmmode\times\else\texttimes\fi{}1, and ($\…
Stable platinum oxide films have been prepared through magnetron sputtering and have been analyzed on the bases of energy-sensitive microanalyses, x-ray diffraction, resistivity, and optical reflectance measurements. The complex dielectric function has been determined for various oxygen contents in the film covering t…
Effect of curvature-induced strain on the covalent bonding in isolated and selected single-shell and multi- shell carbon nanotubes is explored, using electron energy-loss spectroscopy (EELS) on the core K level, which probes the distribution of available unoccupied states in the conduction band. Results show that the…
We have studied luminescence properties of nanometer-sized Si crystallites fabricated by laser breakdown of ${\mathrm{SiH}}_{4}$ gas. An exponential absorption tail is observed and red photoluminescence (PL) appears in the exponential tail. The PL decay behavior is characterized by a stretched exponential function. At…
Quantum-beat spectroscopy has been used to observe excited states of the N-V center in diamond. For the 1.945-eV optical transition, direct evidence is presented for the existence of GHz-scale fine structure, together with a much larger 46-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ level splitting in the E state. An i…
The orbital and spin orderings of ${\mathit{d}}^{2}$ Jahn-Teller systems are studied in the generalized gradient approximation (GGA) by using the full-potential linearized augmented-plane-wave method. For the low temperature distorted crystal structures in ${\mathrm{YVO}}_{3}$ and ${\mathrm{LaVO}}_{3}$ perovskites, we…