Materials Literature
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The normal way to calculate the Peierls energy for dislocations follows the procedure of Peierls and Nabarro, who summed the atomic misfit energy in the glide plane at the position of the atoms. Since the misfit energy is not localized but rather contained in the electron distribution, some averaging must be made. Thi…
We have studied the electronic structure of ${\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{VO}}_{3}$ by x-ray-absorption and resonant photoemission spectroscopy. Upon hole doping the parent Mott-Hubbard insulator ${\mathrm{YVO}}_{3},$ an insulator-metal transition occurs at around $x\ensuremath{\approx}0.5.…
The genetic algorithm approach, in which a population of trial structures is allowed to evolve subject to well-defined procedures for mating, mutation, and natural selection, was employed to solve the complex molecular crystal structure of Ph2P(O)(CH2)7P(O)Ph2 directly from powder diffraction data. The structure solut…
The behavior of excess carbon in cubic SiC films was investigated using infrared absorption spectroscopy of modes which were optically activated by defect-induced strain in the film. The results show that the excess carbon which is formed interstitially in the region of SiC grain boundaries as an interstitial phase, c…
Various hydrogenated amorphous carbon films have been analyzed by C13 and H1 nuclear magnetic resonance (NMR) spectroscopies. The films have been deposited from acetylene or cyclohexane by dc plasma enhanced chemical vapor deposition, at various dc biases and gas pressures. The total hydrogen content has been measured…
Phosphate acetyltransferase (PTA) and acetate kinase (AK) of the hyperthermophilic eubacterium Thermotoga maritima have been purified 1,500- and 250-fold, respectively, to apparent homogeneity. PTA had an apparent molecular mass of 170 kDa and was composed of one subunit with a molecular mass of 34 kDa, suggesting a h…
Monte Carlo simulations have been performed on a meso-scale polymer model for semiflexible chains and effective polymer-polymer interactions. Simulations were made for different chain lengths at dilute and semidilute concentrations. The correlation length and osmotic compressibility have been determined for the simula…
Formation of different crystallographic phases and their characteristic Raman and infrared spectra are studied in the manganite system La1−xBaxMnO3 for x in the range of 0⩽x⩽1, and with variations in oxygen stoichiometry. Synthesis of the end member LaMnO3 in pure argon environment leads to the formation of Jahn–Telle…
An aspartate kinase-deficient mutant of Thermus thermophilus, AK001, was constructed. The mutant strain did not grow in a minimal medium, suggesting that T. thermophilus contains a single aspartate kinase. Growth of the mutant strain was restored by addition of both threonine and methionine, while addition of lysine h…
The physical and electronic structure of the dispersed and $(2\ifmmode\times\else\texttimes\fi{}2)$ phases of K/graphite have been characterized by valence and core-level photoemission. Charge transfer from K to graphite is found to occur at all coverages, and includes transfer of charge to the second graphite layer.…
The conductance of carbon nanotubes with a vacancy is studied in a tight-binding model. We examine the Fermi energy ε dependence of the conductance and show it is quantized into zero, one, and two times the conductance quantum \(e^{2}/\pi\hbar\) depending on the type of vacancy in the half-filled case, i.e., ε= 0. In…
Magnetic anisotropy of La0.8Ca0.2MnO3 (LCMO) epitaxial thin films grown on (001) SrTiO3 and LaAlO3 a substrates exhibits strong correlation with substrate-induced strain states as determined by normal and grazing incidence x-ray diffraction. In a 250 Å thick LCMO (001)T film grown on SrTiO3 substrate, an in-plane biax…
X-ray reflectivity by rough multilayer gratings is treated in the framework of kinematical and dynamical theories. The kinematical scattering integral is calculated without the restrictions of the Fraunhofer approximation. The dynamical theory is presented by the matrix modal eigenvalue approach. In both theories we g…
The holmium and europium complexes of the tetraanion of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (H4DOTA), namely, sodium aqua(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetato)-holmium(III) tetrahydrate, Na[Ho(C 16 H 24 N 4 O 8 )(H 2 O)].4H 2 O, and sodium aqua(1,4,7,10-tetraazacyclododecane-1,4,7,…
The Berreman 4×4 matrix method is extended in order to calculate the optical behavior of reflective liquid crystal displays. Expressions for the reflection matrix and the reflection coefficient are derived. Possibly present uniaxial and/or biaxial retarders can be included in the calculation. Conservation of energy an…
We report angle-resolved photoemission spectroscopy (ARPES) on a single Cu-O chain compound ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{3}$ with Ne I photons. In contrast with previous ARPES with higher-energy photons, the present result clearly shows two well-separated branches of dispersions near ${E}_{F}$ ascribable to spino…
Electronic structures of halogen bridged mixed-valence (MV) complexes ${\mathrm{Cs}}_{2}{\mathrm{Au}}_{2}{X}_{6} (X$=I, Br, and Cl) have been investigated by means of reflectivity measurements. We have observed five polarization-dependent optical transitions in the energy range of 0.6--5.5 eV. The lower-lying three ba…
The temperature (10--290 K) and magnetic-field (0--7 T) dependencies of optical spectra and their anisotropy have been investigated for a single crystal of ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}(x=0.4),$ which undergoes a charge and orbital ordering transition at ${T}_{\mathrm{co}}=235 \m…
We report the observation of a strongly coupled first-order charge-density wave (CDW) transition in a high-quality single crystal of the intermetallic compound ${\mathrm{Lu}}_{5}{\mathrm{Ir}}_{4}{\mathrm{Si}}_{10}.$ The first-order nature is ascertained by a very narrow and huge cusp (360 J/mol K) in the specific heat…
Suppression of the multiphoton fluorescence contribution to the hyper-Rayleigh (second-order nonlinear optical) scattering signal was recently achieved by intrinsic demodulation of the fluorescence at high amplitude-modulation (AM) frequencies [Olbrechts et al., Rev. Sci. Instrum. 69, 2233 (1998)]. These high AM frequ…