Materials Literature
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The sharp component observed in the critical scattering above the cubic-to-tetragonal phase transition in SrTiO 3 is now generally considered as a surface-related phenomenon. In the present paper, for the first time, the structural difference between the bulk and a skin layer of a highly perfect crystal has been shown…
Aromatic polyesters were prepared and used to improve the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane and o,o′-diallyl bisphenol A. The aromatic polyesters contain poly(ethylene phthalate) (PEP) and poly(ethylene phthalate-co-ethylene isophthalate) (10 mol % isophthalate unit) (…
We have studied the electronic and structural properties of native defects in cubic boron nitride (nitrogen vacancy, boron antisite, and oxygen substitutional) using all-electron first-principles total-energy calculations. We find that all defects introduce a deep state above the middle-energy gap. These defects prese…
The spin dynamics of La 1- x Sr x MnO 3 for Sr concentrations of x ≤0.3 were studied by inelastic neutron scattering. For the entire concentration range studied, we found that the spin-wave stiffness constant D and the paramagnetic spin-diffusion constant A * are ruled by the nearest neighbor interaction, i.e., the st…
${\mathrm{C}}_{3}{\mathrm{N}}_{4}$ films were prepared on Si(111) by rf plasma-enhanced chemical vapor deposition using ${\mathrm{Si}}_{3}{\mathrm{N}}_{4}/\mathrm{T}\mathrm{i}\mathrm{N}$ and ${\mathrm{Si}}_{3}{\mathrm{N}}_{4}/\mathrm{Z}\mathrm{r}\mathrm{N}$ as transition layers. X-ray diffraction and transmission elec…
Hysteresis loss of natural rubber (NR) and styrene–butadiene rubber (SBR) vulcanizates having variations of loading of carbon black, silica, clay, resin, and curatives has been measured over a wide range of strain rates and temperatures as well as under swollen conditions. Hysteresis loss increases with an increase in…
The room-temperature wall energy σw=4.0×10−3 J/m2 of an exchange-coupled Tb19.6Fe74.7Co5.7/Dy28.5Fe43.2Co28.3 double layer stack can be reduced by introducing a soft magnetic intermediate layer in between both layers exhibiting a significantly smaller anisotropy compared to Tb–FeCo and Dy–FeCo. σw will decrease linear…
Composites with high relative magnetic permeability values can be used in many industrial applications, especially if they can be shaped using conventional polymer-processing technologies. In this study, various hybrid composite systems (i.e., particles with differing aspect ratio, size, and magnetic permeability embe…
The initial cooling of hot carriers and the subsequent exciton formation in GaSe are studied by time-resolved photoluminescence (PL) using femtosecond up-conversion techniques. From the time-resolved PL spectra of this layered III-VI semiconductor two different energy relaxation channels are derived. After an initial…
Double-exchange system is investigated by the dynamical mean-field theory. We show that the chemical potential shifts as a function of temperature and magnetization, which is anomalously large. We also discuss the influences of dynamic Jahn-Teller effect to the shift of the chemical potential. Measurement of the shift…
Ambient pressure Fermi-surface measurements are reported for ${\mathrm{\ensuremath{\kappa}}\ensuremath{-}(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\mathrm{T}\mathrm{T}\mathrm{F})}_{2}{\mathrm{Cu}[\mathrm{N}(\mathrm{CN})}_{2}]\mathrm{Br}.$ The single Shubnikov--de Haas frequency that is detected (3798\ifmm…
We investigate Thomson's problem of charges on a sphere as an example of a system with complex interactions. Assuming certain symmetries we can work with a larger number of charges than before. We found that, when the number of charges is large enough, the lowest energy states are not those with the highest symmetry.…
New luminescent thermally stable lanthanide-organic complexes, namely europium tris(4-methoxy benzoylbenzoate), Eu(MeOBB)3, and terbium tris(4-methoxy benzoylbenzoate), Tb(MeOBB)3, were synthesized and characterized. The UV absorption bands in these compounds are attributed to the ligand while the emission originates…
We report on a comprehensive study of the growth of 5-nm-thick epitaxial Fe(001) films on Ag(001) substrates which are deposited on Fe-precovered GaAs(001) wafers. We characterize the films in situ by scanning tunneling microscopy, low-energy electron diffraction, X-ray photoelectron spectroscopy, and depth profiling…
The temperature dependences of the conductivity and magnetoconductivity of poly(3,4-ethylenedioxythiophene) doped with ${\mathrm{PF}}_{6}$ (room-temperature conductivity of 200--300 S/cm) have been studied; $\ensuremath{\sigma}(T)$ is weakly temperature dependent with the characteristic resistivity ratio ${\ensuremath…
We characterize the high-frequency asymptotic shape of the primary dielectric relaxation for four supercooled liquids: glycerol, propylene carbonate, D-propylene glycol and tricresyl phosphate. Two distinct power laws, with an exact relationship between their exponents, exist above the peak in the imaginary part of th…
We present here a scanning tunneling microscope study of the initial bonding structure and subsequent reaction mechanism of ${\mathrm{C}}_{2}{\mathrm{H}}_{2}$ with the Si(001) surface. Upon exposure of the sample at room temperature to 0.2 L of ${\mathrm{C}}_{2}{\mathrm{H}}_{2}$ (approximately 20% coverage) adsorption…
A quantitative theory of the kinematical diffraction of a plane wave by a carbon nanotube is developed. The formalism is based on the Cochran, Crick, and Vand theory of the diffraction by helical molecules. This leads to a closed-form expression of the diffracted amplitude produced by a single-wall tubule of arbitrary…
The single-crystal characterization of potassium disilver tetrathioarsenate(V), KAg2AsS4, was determined. The structure type for this phase has been observed previously. This structure contains AsV and AgI atoms tetrahedrally coordinated to sulfur atoms while K+ cations are surrounded by eight sulfur atoms in a compre…
Polyolefin/polystyrene (PS) blends are difficult to compatibilize using in situ reactive compatibilization techniques, because neither of these polymers has any functional groups that one can use in the formation of a copolymer from these polymer components. In this study, the Friedel–Crafts alkylation was realized in…