Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The interstice statistics of the oxygen sublattice of the canonical inorganic glass-former silica have been investigated theoretically for a number of structural models of v-${\mathrm{SiO}}_{2}$. It is found that spheres with radii smaller than 2.41 \AA{} minus the oxygen radius can travel freely through a model of v-…
Thin films were deposited by pulsed uv-laser (ablation) deposition of Y1Ba2Cu3O7−x (YBCO), and composite zirconia and yttria targets onto silicon wafers. These films were analyzed to ascertain the chemical and physical structure of the film interfaces and further the development of Si substrates for superconducting YB…
Multiple-scattering theory is generalized to take into account the effects of spin-orbit interaction and spin polarization of the photoelectron that are at the origin of the magnetic x-ray circular dichroism (MXD) effect observed in x-ray-absorption spectra where the final state of the photoelectron is delocalized. Th…
Cristallisation dans C2/c avec a=17,649, b=12,143, c=5,3688 A, β=105,756 o , Z=4, affinement jusqu'a R=0,025. Le compose cristallise dans une structure semblable a la scheelite avec une relation d'ordre a une dimension entre les atomes de K et ceux de Th. La maille monoclinique est reliee a celle de CaWO 4 quadratique…
The combined techniques of surface extended x-ray-absorption fine structure (SEXAFS) and high-resolution core and valence photoelectron spectroscopy have been used to study the local bonding structure of the Sb/Si(111) interface. From photoemission, we find that the Sb atoms adsorb in a unique environment that complet…
Electrodeposited films of cuprous oxide show high resistivities in the range of 109–1012 Ω cm. The p-type conductivity, its temperature dependence, and its thermostimulated characteristics can be explained by assuming that a pair of deep levels (acceptor and donor type) control the electrical properties of these films…
The strain of porous Si formed on p+-Si wafers without and with GeSi or CoSi2 capping layers were analyzed by double crystal x-ray diffractometry, MeV 4He backscattering spectrometry, and Auger electron spectroscopy. The parallel strain is zero for all the samples. The perpendicular strain of uncapped porous Si is pos…
The nucleation fields under coherent rotation for uniaxial ferromagnets are rigorously determined including the second anisotropy constant K2. Theoretical studies cover the whole range of the relationships between K1 and K2. We show that the reversal processes can be classified into eight types depending on the parame…
Partial radial distribution functions of standard Monte Carlo simulations were used as input for Reverse Monte Carlo simulation, a novel method for structural modeling. From detailed comparison of the two independent (MC and RMC) particle configurations it has turned out that sufficiently close agreement in radial dis…
Electrical conductivity measurements were performed on ${\mathrm{TlInSe}}_{2}$ and ${\mathrm{TlInTe}}_{2}$ single crystals. The corresponding current-voltage (I-U) characteristics consist of two parts: An Ohmic part, at low current densities, and a nonlinear one of the S type, at moderate and higher current densities.…
A comprehensive theoretical analysis is presented which accounts for nuclear spin relaxation due to molecular surface diffusion on spheroidal aggregates undergoing restricted rotational diffusion in a uniaxial potential of mean torque. The model is formulated primarily with surfactant systems in mind, and should provi…
Cross sections for oxidation reactions of boron cluster ions (B+1–14) with CO2 are reported as a function of collision energy. The results give insight into the oxidation mechanism and are a sensitive probe of the B+n–O bond energy. In addition, collision-induced dissociation (CID) was used to measure the stabilities…
This report presents measurements of the frequency dependent dielectric loss ε″(ω) and quasielastic light scattering of thermal density fluctuations of simple organic glassforming van der Waals liquids BCDE (bis-phenol-C-dimethylether) and BKDE (bis-kresol-C-dimethylether) having glass transition temperatures of Tg=24…
The difference in phonon energies and broadenings between an isotopically enriched crystal of $^{70}\mathrm{Ge}$ (95.9%) and a germanium crystal of natural isotopic composition was measured with high accuracy in first- and second-order Raman spectra (with laser excitation energies of ${\mathit{E}}_{\mathit{L}}$=2.41 e…
The electromigration failure distribution for fine-line interconnects is unknown, but expected to be strongly affected by microstructure. Results from tests on lines with controlled grain sizes and distributions of grain sizes argue for a series model of failure elements in fine lines. A new statistical model of elect…
A single-band model and a three-band model which consists of one σ→σ* and two major π→π* electronic transitions were developed for understanding the refractive index dispersions of uniaxial liquid crystals. This information is particularly important for liquid-crystal-display applications. By comparing the three-band…
Relaxation dynamics of the n=1 and 2 image-potential states on Ag(100) and Ag(111) are investigated using femtosecond pump-probe techniques. Transient two-photon photoemission measurements are performed using femtosecond pulses with photon energies of 2.00 and 4.00 to 4.35 eV, generated via self-phase modulation and f…
The Adam–Gibbs theory of relaxation for glass-forming liquids is based on an ensemble of independent and equivalent cooperatively rearranging regions (CRR’s). In this work we extend the Adam–Gibbs theory by incorporating the mutual interactions between the CRR’s. This is done by the method of the coupling scheme in wh…
Absolute photoabsorption cross sections of free neutral sodium clusters containing from N=3 to 40 atoms are presented. Investigation of a wide continuous range of cluster sizes reveals the size development of the photoabsorption behavior. In the smallest clusters the absorption is moleculelike. A transition to collect…
Graphitization of amorphous carbon has been studied at high static pressures up to 15 GPa and high temperatures up to 1300 °C, primarily under diamond-stable conditions. Upon heating at 2 GPa, amorphous carbon turns into graphite at ∼900 °C. The temperature for the graphitization decreases with increasing pressure and…