Materials Literature
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We report measurements of the thermoelectric power and conductivity of ‘‘new’’ polyacetylene doped with iodine. In highly doped samples in which the conductivity extrapolates to finite values at zero temperature, we observe a nonlinearity in the thermopower very similar to that characteristic of the electron–phonon ef…
Room temperature, time-of-flight, powder neutron diffraction measurements on cupric oxide, CuO, at ambient and 22(1) kbar hydrostatic pressure have provided the pressure dependence of the monoclinic lattice parameters and the single positional parameter, namely the y parameter of oxygen. The percentage changes in the…
The optical absorption spectrum (2 eV∼6.8 eV), the Ce 3+ emission spectrum (1.8 eV∼2.7 eV) and the excitation spectrum for the 550 nm Ce 3+ emission (2.4 eV∼6.3 eV) have been measured on single crystals of YAG:Ce 3+ . The excitation spectrum for the 550 nm emission (2.7 eV∼11.2 eV) is also reported on powder phosphor…
Geometries and electronic structures of the B12 cluster have been investigated using a Car–Parrinello ab initio molecular dynamics simulation. The icosahedral structure, which is commonly found in bulk boron compounds, is locally stable, but has a few dangling bonds. On melting and annealing, this structure rearranges…
Porous silicon/silicon structures under anodic oxidation conditions give rise to an electroluminescence phenomenon in the visible range. Using an optical multichannel analyzer the spectral distribution of the emitted light was measured−in situ−during the anodic oxidation step. Recorded spectra show a maximum which shi…
We have measured the carbon K near-edge x-ray-absorption fine structure of graphite by transmission, electron yield, and fluorescence yield. A rounded and prominent peak is identified in the near-edge spectrum, among the other well-known spectral features. With the aid of a full-potential linearized augmented-plane-wa…
Surfaces of yttria, zirconia, and yttria-stabilized zirconia were studied using x-ray photoelectron spectroscopy. An almost threefold increase in the surface yttrium concentration was observed in the yttria-stabilized zirconia samples. The core level binding energies of yttrium, zirconium, and oxygen ions in yttria-st…
The electronic structure of MnO has been investigated using high-energy (x-ray photoelectron and bremsstrahlung-isochromat) spectroscopies. An experimental gap of 3.9 eV is found. By comparing the experimental results to a configuration-interaction cluster model, values for the different parameters in a model Hamilton…
We propose a form for the exchange-correlation potential in local-density band theory, appropriate for Mott insulators. The idea is to use the ``constrained-local-density-approximation'' Hubbard parameter U as the quantity relating the single-particle potentials to the magnetic- (and orbital-) order parameters. Our en…
With respect to frequently desired actuators, high-signal electrostrictive deformation is an electromechanical alternative to the piezoelectric effect. Several disadvantages, which conflict with general applications, are investigated. Possibilities to overcome or reduce such disadvantages are discussed and suitable ma…
Thermal endurance characterization of XLPE cable models is realized by applying conventional procedures and an analytical method. The latter method is based on oxidation induction time measurements to estimate the activation energy of the degradation reaction and then the slope of the thermal endurance line. The conve…
We review the recent theoretical developments in the study of domain structure dynamics through nucleation-and-growth processes of first-order phase transitions with non-conserved order parameters. We introduce the spatial and space-time correlation functions of the domain structures based on the model proposed by Kol…
A new 2×2 propagation matrix for obliquely propagating light is used to compute the electro-optics of an electrically controlled birefringence liquid-crystal display, with arbitrary viewing angle. The results are the same as those obtained by the generalized geometrical optics approximation and are in good agreement w…
The structure and magnetic properties of yttrium diphthalocyanine [${\mathrm{YPc}}_{2}$]\ensuremath{\cdot}${\mathrm{CH}}_{2}$${\mathrm{Cl}}_{2}$ are reported. Phthalocyanine macrocycles are stacked above each other in one direction, with a staggered angle of 45\ifmmode^\circ\else\textdegree\fi{}. One-dimensional organ…
In order to investigate the effect of the spin-orbit interaction on strong magnetism, the authors have developed a method of electronic structure calculation which includes the spin-orbit interaction in an approximate way into the semi-relativistic LMTO Hamiltonian. In this way both the spin-orbit interaction and the…
Copper is a possible substitute for Al in very large scale integration interconnects because of its higher resistance to electromigration damage (EMD) and its lower electrical resistivity. In the present work, we report on electrical resistance measurements of the activation energy for EMD in Cu films as determined by…
The plate-shaped crystals of rat bone are arranged in parallel layers that form coherent structures up to the level of individual lamellae. The crystal layers of the thin lamellae are parallel to the lamellar boundary, whereas those of the thicker lamellae are oblique to the boundary. The basic structure of rat bone c…
Biquadratic coupling between two order parameters Q1 Q2 can lead to transitions between a phase with only one of the two order parameters active (phase I or II) and a mixed phase III in which both order parameters are symmetry breaking. Domain walls for positive coupling energies are chiral under thermodynamic conditi…
Abstract The use of plasma deposition to introduce sulfonate groups to the surface of a polyurethane was attempted. In previous work, the bulk incorporation of sulfonate groups was found to improve the blood contacting properties of the base polyurethane but physical properties in the hydrated state were adversely aff…
Abstract The structural hierarchy in injection molded blends of poly(ethylene terephthalate) (PET) and a commercial liquid crystal polymer (LCP), two immiscible polymers, was characterized at various blend compositions. The macroscopic core and skin have a gradient structure and are subdivided into ordered and disorde…