Materials Literature
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Optical absorption spectra were measured around the band edge in ( CH 3 NH 3 ) 3 Bi 2 I 9 single crystals. In the very thin crystals, an intrinsic exciton band appears clearly at 2.51 eV at low temperatures, and the absorption peak remains even at room temperature reflecting a large binding energy of more than 300 meV…
Ab initio calculations have been made of possible excited electronic structure of the N-V center in diamond. Molecular-orbital basis states for a center of ${\mathit{C}}_{3\mathit{v}}$ symmetry with n=2, 4, or 6 active electrons, which account fully for spin symmetries of the wave functions, were constructed to permit…
The resistivity, thermoelectric power (TEP), ESR and static susceptibility were measured on κ- and κ'- (BEDT-TTF) 2 Cu 2 (CN) 3 ; also, a band calculation based on an extended Hückel method was re-examined and the results were compared with those of related BEDT-TTF (ET) salts. Although the crystal- and calculated ban…
Carbon is well-known as an insulator, a semimetal, a molecular solid, and a one-dimensional semiconductor or low-density-of-states metal. We propose a pure-carbon planar structure composed of pentagons and heptagons that is metallic with a density of states at the Fermi level of \ensuremath{\sim}0.1 state per eV per a…
Collagen is most abundant in animal tissues as very long fibrils with a characteristic axial periodic structure. The fibrils provide the major biomechanical scaffold for cell attachment and anchorage of macromolecules, allowing the shape and form of tissues to be defined and maintained. How the fibrils are formed from…
We report the transient photovoltaic characters of a Schottky-type porous silicon diode excited by 10 ns laser pulses at 532 nm. At room temperature, the transient photovoltage profile consisted of two different decay components. The fast one had a characteristic decay time of 44 ns and the dominant slow process one o…
CASSCF/MRCI calculations have been performed for five states of ScCl , , , and for which values of the spectroscopic constants , , and are reported.
New silver complexes of alkenes of empirical formula (β-diketonato)Ag(VTES), where β-diketonato = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato (hfac) ( 1 ), 1,1,1-trifluoro-2,4-pentanedionato (tfac) ( 2 ), and 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionato (fod) ( 3 ) and VTES = vinyltriethylsilane, were prepar…
The ceramic form of is of commercial importance as a ceramic capacitor dielectric and it is of scientific interest since it provides a straightforward example of the effect of solid solution composition of ceramics on dielectric properties. This paper presents the results of a sufficient number of measurements of the…
The structures of two fast-ion-conducting molecular glasses, and , have been investigated by neutron and x-ray diffraction. Both molybdate and tungstate glasses show a first sharp diffraction peak (FSDP) at very low Q-values ( and respectively) in the neutron data. However, only weak peaks are observed at similar Q-va…
We report the magnetic field dependence of microwave absorption at low fields (200 Oe), in thin film and bulk samples of La1−xBaxMnO3−z. We demonstrate, using a very simple cavity configuration, that the magnetic field sensitivity of the microwave response of the giant magnetoresistance materials offers possibilities…
The structural, magnetic, and transport behavior of orthorhombic, insulating ${\mathrm{La}}_{0.875}{\mathrm{Sr}}_{0.125}{\mathrm{MnO}}_{3+\ensuremath{\delta}}$ were studied as a function of temperature from 20 to 300 K. Upon cooling from room temperature, we observe the rapid development of a large breathing-mode dist…
The very first low-frequency infrared absorption and Raman scattering spectra of TTF-CA are presented. Several studies have been performed as a function of temperature at atmospheric pressure. In the neutral phase by infrared absorption, we have emphasized the critical behaviour of an antisymmetric lattice mode (locat…
We have measured the optical properties of the linear chain compound bis-(tetramethyltetraselenafulvalene)hexafluorophosphate, $(\mathrm{TMTSF}{)}_{2}{\mathrm{PF}}_{6}$, in the spin-density-wave state which develops below ${T}_{\mathrm{SDW}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}12$ K. In the direction per…
We use low-frequency electrophoresis to crystallize monodisperse charge-stabilized colloidal suspensions. Rather than reverting directly to their equilibrium fluid state when the field is removed, some suspensions retain long-lived metastable crystallites whose evolution we track using high-resolution digital video mi…
An abrupt and large increase in the absolute magnitude of λs in sputtered polycrystalline permalloy (Ni81Fe19) films for thicknesses below 7 nm was observed. Permalloy films maintain near-zero magnetostriction with film thicknesses above 7 nm. Film surface studies and microstructural characterizations suggest that the…
Dynamics of phase separation in a polymerizing system, consisting of carboxyl terminated polybutadiene acrylonitrile/epoxy/methylene dianiline, was investigated by means of time-resolved light scattering. The initial length scale was found to decrease for some early periods of the reaction which has been explained in…
Thin amorphous films of tungsten oxide (WO3) are well known to change their optical absorption behavior upon light exposure, usually referred to as photochromic effect. Since the formation of color centers is closely related to the optical creation of electron-hole pairs the sensitivity of the photochromic effect in W…
Thermal chemical vapor deposition was used to deposit fluorocarbon films with chemical resemblance to bulk polytetrafluoroethylene. X-ray photoelectron spectroscopy revealed that the films deposited from thermal decomposition of hexafluoropropylene oxide had fluorine to carbon ratios of 2.0 and CF2 fractions of 90% al…
We report the observation of steps at regular intervals of magnetic field in the hysteresis loop of a macroscopic sample of oriented M${\mathrm{n}}_{12}$${\mathrm{O}}_{12}$(C${\mathrm{H}}_{3}$COO${)}_{16}$(${\mathrm{H}}_{2}$O${)}_{4}$ crystals. The magnetic relaxation rate increases substantially when the field is tun…