Materials Literature
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We study the antiferromagnetic phase of the C60-polymer doped with one electron per one C60 by using a tight-binding model with long-range Coulomb interactions. The model is solved by the unrestricted Hartree-Fock approximation, and a phase diagram is obtained by changing Coulomb interaction strengths and a conjugatio…
We calculate the consequences of molecular exchange between two states with different relaxation rates in dielectric spectra. In a critical range where exchange rates are of the order of the relaxation rates, both individual processes show apparently increased relaxation frequencies, and the slower process gains inten…
The surface structures of homoepitaxial diamond (001) films have been studied by using scanning tunneling microscopy. Boron-doped films were grown on natural diamond substrates. Images showed a dimer-type 2×1 reconstruction with well-resolved dimers. The surface consists of alternating terraces of 2×1 and 1×2 dimeriza…
By using the mass-analyzed low energy dual ion beam deposition technique, a high quality epitaxial, insulating cerium dioxide thin film with a thickness of about 2000 Å has been grown on a silicon (111) substrate. The component species, cerium and oxygen, are homogeneous in depth, and have the correct stoichiometry fo…
The thermalization of electrons in copper nanoparticles embedded in glass is investigated using femtosecond pump-probe spectroscopy. The time dependent induced transmission is enhanced near the surface plasmon resonance of the nanoparticles, as opposed to the static one obtained with thermomodulation measurements. In…
Pr 3 (SiO 4 ) 2 Cl is isostructural with La 3 (SiO 4 ) 2 Cl. The Pr(1)O 7 Cl polyhedron is irregular. The Pr(2)O 8 Cl 2 polyhedron is a distorted square antiprism with the Cl atom capping distorted square faces. The site of Pr(2) can also be described as at the centre of a Pr(2)(SiO 4 ) 4 Cl 2 octahedron. The structur…
We present the results of detailed electrical measurements on diamond films grown by hot-filament chemical-vapor deposition. Two different mixtures of reaction species, hydrogen/methane and hydrogen/acetone, were utilized to grow diamond films. The latter is useful for introducing dopants during growth in a relatively…
Poly(3-hydroxybutyrate) (PHB)-negative mutants of Bacillus megaterium were isolated following mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine. Different strategies were used for isolation, including ultracentrifugation through sucrose gradients and selection for resistance to allyl alcohol. The mutants were dete…
Distannoxane complexes catalyze the ring-opening polymerization of optically active β-butyrolactone (β-BL) to afford a high molecular weight poly(3-hydroxybutyrate). When 1-ethoxy-3-chlorotetrabutyldistannoxane was used as a catalyst (catalyst/(R)-β-BL = 1/8000 at 100 °C for 4 h), poly((R)-3-hydroxybutyrate) was obtai…
Parallele Schichten aus Fe‐ und O‐Atomen charakterisieren den Clusterkern des zehnkernigen Fe III ‐Komplexes 1 (dbm = Dibenzoylmethan), der durch kontrollierte Hydrolyse aus FeCl 3 entsteht. Die O‐Atome in 1 bilden dabei in Analogie zu denen in einigen Eisenoxiden und ‐hydroxiden eine kubisch dichteste Packung. Die sc…
The structure consists of layers of Ag(CN) 2 - ions arranged in such away that trigonal prisms of N atoms are formed. Each prism is occupied by an Eu 3+ ion, to which three H 2 O molecules coordinate and complete the tricapped trigonal geometry.
Polarized properties of both the singlet and triplet ground exciton states in the photoluminescence and transmission spectra of crystalline GaTe are explained based on the possible symmetry properties of the energy band edge of GaTe. Some experimental results about excited exciton states in GaTe are presented and disc…
Crystal structure of K 2 Co 2 (SO 4 ) 3 was determined at nine temperatures in the high-temperature cubic phase. In contrast to the early structural study, the split-atom calculation concludes that the SO 4 ion has a number of equilibrium arrangements. Mean-square atomic displacements become large with approaching the…
Spatial resolution of optically addressed spatial light modulators (OASLMs) is degraded by several different transfer processes in these devices. We have developed a general transient charge transport model to calculate and simulate the resolution limits of OASLMs due to the following charge spreading mechanisms durin…
During the growth phase of Alcaligenes eutrophus, it was observed that the concentrations of glucose and ammonium ions are inhibitory at a certain level, which affects the specific growth rate. Moreover, it has been established from previous work that (an) unidentified substance(s) inhibit(s) the growth at biomass con…
We have observed the unoccupied partial Pd 4d density of states in Cu-Pd alloys by bremsstrahlung isochromat spectroscopy (BIS). It shows the filling of the Pd 4d band upon alloying, which is consistent with the Pd ${\mathit{L}}_{\mathrm{III}}$ absorption spectroscopy measurements. We have also determined the total ch…
Addition of germanium to the Se–Te alloy causes structural changes which modify the band structure and hence the electrical properties of the Se–Te alloy. In the present work, electrical, optical, and structural properties of Se–Te–Ge have been studied. The activation energies calculated from the dc resistivity measur…
The considerable industrial interest in the qualitative and quantitative production of polyhydroxyalkanoates in microorganisms has led to the characterization of those synthesized in the nitrogen-fixing bacteria Azospirillum brasilense and Azotobacter paspali. In contrast to some other bacterial species, Azospirillum…
Neutron diffraction has been used to determine the location and concentration of C in Nd2Fe17 and in a Si substituted alloy. The results indicate that two carbide phases exist. One contains nearly three C atoms per formula unit, while the other has a much lower concentration. The high C phase contains C only on the 9e…
Large photoinduced absorption is observed in free-standing porous-silicon films in the spectral range from 1.1 to 2.5 eV by using a femtosecond pump-and-probe technique. The measured nonlinear transmission spectra have a very fast component with initial decay on the subpicosecond time scale. The spectral structure and…