Materials Literature
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Higher order correlation functions as observed in four-dimensional NMR experiments on glass-forming liquids are interpreted in terms of a simple model for molecular reorientations. Its key assumption is an intrinsic link between the rotational and structural relaxation of the liquid. It is shown that the introduction…
We have studied the photoluminescence (PL) mechanism of crystalline Si single quantum wells sandwiched between ${\mathrm{SiO}}_{2}$ layers by site-selective excitation spectroscopy. The asymmetric PL spectrum is observed in the red spectral region at low temperatures and can be divided into two PL bands. The peak ener…
We have studied the electronic structure of ${\mathrm{CrO}}_{2}$ by photoemission spectroscopy and specific heat measurements. The Cr $3d$ band shows a splitting into the upper and lower Hubbard bands with a small but finite density of states at the Fermi level, consistent with its metallic behavior. The small renorma…
Macrophages were elicited by the subcutaneous implantation of ultra high molecular weight polyethylene (UHMWPE) for periods of 2, 7, and 14 days in rats. Exudates of varying volumes were produced that was comprised of granulocytes, monocytes, immature and mature macrophages, and T-lymphocytes. No B-lymphocytes were ob…
Iron monocarbide has been investigated between 12 000 and 18 100 cm−1 in a supersonic expansion by resonant two-photon ionization spectroscopy. Six new electronic states have been identified for which origins relative to the ground state have been determined. Three of these possess Ω′=3, one possesses Ω′=4, and two po…
The remarkably simple synthesis of tetrathia- and tetraoxarubyrins 1 and 2 is achieved by the routes presented here. Spectroscopic, 1H NMR, and electrochemical data suggest that 1, 2, and their protonated derivatives are aromatic 26 π electron systems, and the protonated derivatives form stable complexes in solution w…
The properties of sodiumnitroprusside (Na2[Fe(CN)5NO]*2H2O) are investigated by density functional theory. The calculated results both for the free anions as well as for the solid show that the ground-state Born–Oppenheimer surface has local minima for sidewards bonded and inverted NO. The calculated properties for th…
We present a method for simulating the chemical vapor deposition (CVD) of thin films. The model is based upon a three-dimensional representation of film growth on the atomic scale that incorporates the effects of surface atomic structure and morphology. Film growth is simulated on lattice. The temporal evolution of th…
A multiple-scattering formalism, based on the reflectivity matrix method of diffuse reflection high-energy electron diffraction (RHEED), is developed that allows us to calculate the electron-phonon scattering in RHEED due to correlated thermal vibrations for the case of one-phonon transitions. The scattering by the th…
Hyphoinycete assemblages, conidia in foam aiid thow prodticed o11 leal litter of three species (Plaruriua orirrifci l is. Populus riigrci aiid Srilix crtrociriereci), and reproductive activity oí the fungi colonizing leaves, were studied al four sites located in two Mediterranean inotintaiii streaiiis coiitraiting i n…
The global dynamics of polyisoprene (PI) in the controlled porous glass (CPG) Bioran have been studied with dielectric spectroscopy by varying the end-to-end vector (⟨ r 2 ⟩ 1/2 ) of the chain from dimensions smaller to much larger compared to the pore radius. Pulsed-field gradient NMR is used for the same systems and…
Magnetotransport properties of an 80 nm-thick high quality epitaxial film of SrRuO 3 grown on SrTiO 3 (001) were investigated. The film has tetragonal structural symmetry ( c -axis ⊥ film plane), and shows a uniaxial strong magnetic anisotropy with the easy axis along the c -axis. Magnetotransport phenomena are also u…
The origins of two types of electromigration failure models are explored starting with the basic transport differential equations including the effects of electromigration-induced mechanical stress. We compare the results of a nucleation model, in which failure is determined by the time required to build up a critical…
The charge ordering process of a mixed valence LuFe 2 O 4 system has been studied, focusing attention on the frustration effect associated with the charge configuration. It is revealed that the system undergoes successive phase transitions following the sequence of disorder→2D CDW→3D CDW. In the 2D-CDW state, the char…
Molecular wires 2 are formed by the stacking of Sn triangles 1 in BaSn3. The balanced interplay of interactions between localized and delocalized structural components is responsible for the super-conductivity of 2. The “fingerprint” in the band structure of this superconductor is discussed with the help of partial el…
A high‐spin ground state characterizes the cubane complex, which was obtained from copper( II ) acetate monohydrate and the bridging ligand 2‐(4‐hyroxysalicylidenamino)ethanol. In the crystal these cubane clusters are arranged to give a channel structure (depicted on the right), which is attributed to a hydrogen‐bondi…
Hydrothermal syntheses in fluoride medium readily yield very open materials, as the example of ITQ-3 demonstrates. This new polymorph of silica with the formula [SiO2]64 has a framework characterized by a low density (16.3 SiO4 tetrahedra per 1000 Å3), a very large void volume (0.23 cm3 g−1), and a two-dimensional sys…
We have investigated the morphology of lamellar polystyrene-polymethylmetha cry late diblock copolymers in the ultrathin-film limit, spin-cast and annealed on silicon nitride substrates. Our experiments show evidence for a morphology change from lamellar domains parallel to the substrate to perpendicular domains that…
Amorphous carbon films with high sp3 content were deposited by magnetron sputtering and intense argon ion plating. Above a compressive stress of 13 GPa a strong increase of the density of the carbon films is observed. We explain the increase of density by a stress-induced phase transition of sp2 configured carbon to s…
A study of the electronic structure of about thirty transition-metal sulphides (TMS) of various stoichiometries and crystal structures is presented, supplementing recent studies of their structural and cohesive properties (P Raybaud, G Kresse, J Hafner and H Toulhoat, preceding paper). The electronic structure of the…