Materials Literature
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The densification behavior of nanocrystalline Ce 0.8 RE 0.2 O 1.9 (RE = La, Nd, Sm, Gd, Dy, Y, Ho, Er, and Yb) solid-solution oxides, synthesized via carbonate coprecipitation, has been investigated in air by means of constant-rate-of-heating sintering and the conventional ramp-and-holding sintering methods. Fully den…
Lead zinc niobate-lead titanate (PZN-PT) single crystals are able to sustain very large piezoelectric strains, a phenomenon for which the term `giant piezoelectric effect' was recently coined. PZN-4.5%PT crystals were studied by means of single-crystal neutron diffraction at temperatures between 293 K and 438 K. Two p…
The photoluminescence spectra of spherical CdTe nanocrystals with zincblende structure are studied by size-selective spectroscopic techniques. We observe a resonant Stokes shift of 15 meV when the excitation laser energy is tuned to the red side of the absorption band at 2.236 eV. The experimental data are analyzed wi…
Electrochemical combination of the magnetic dinuclear anion [MM'(C2O4)(NCS)8](4-) (MM' = Cr(III)Cr(III), Cr(III)Fe(III)) with the ET organic pi-donor (ET = BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) gives rise to two new isostructural molecular hybrid salts ET5[MM'(C2O4)(NCS)8], with MM' = CrCr (1), CrFe (2). T…
Intercalation complexes of a conjugated substituted polyacetylene and montmorillonite were prepared through spontaneous polymerization of 2-ethynylpyridine within the galleries of montmorillonite. Protons are thought to be at the origin of spontaneous polymerization of 2-ethynylpyridine. X-ray data support the model o…
Dielectric relaxation properties of dehydrated and hydrated Na-mordenite are measured by means of thermally stimulated depolarization current (TSDC) spectroscopy. TSDC spectroscopy allows us to determine two characteristic terms which depend on the hydration state: on one hand, the site selectivity of sodium ions and…
Crystallography provides a unique insight into the structural properties of polymer electrolytes. Knowledge of the crystal structures helps in the understanding of the structural chemistry of such electrolytes and facilitates the design of electrolytes with a higher conductivity for applications in new devices such as…
The interfacial behavior of third and fourth generations of hyperbranched polyesters (HBP3 and HBP4) with 32 and 64 hydroxyl-terminal groups was studied with scanning probe microscopy. The molecular adsorption on a bare silicon surface of both hyperbranched polymers was described in the terms of the Langmuir isotherm.…
We have determined elasticity data of various ovalbumin gels as a function of concentration of ovalbumin and analyzed these data in terms of a percolation model. In addition, we have analyzed elasticity data of a multitude of other protein gels. We find that all data can be described by one percolation model. The crit…
Two types of photoresponsive liquid-crystalline (LC) networks with macroscopic uniaxial molecular orientation were prepared by polymerizing mixtures of a LC monoacrylate, a LC diacrylate and an azobenzene compound in a homogeneous glass cell at a nematic phase: one was the LC networks doped with azobenzene molecules a…
Colloidal silver nanoparticles were easily obtained by reacting AgX (X = BF 4, PF 6, SbF 6, SO 3 CF 3, ClO 4, NO 3 ) with poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in a mixed solvent system of chloroform and methanol in the absence of UV irradiation. Rapid formation of colloidal silver nanoparticles was also observ…
The iron complexes of N-confused porphyrin, Fe(NCTPP)Br and Fe(NCTPP)(SC7H7), are synthesized. The solid-state structures show nonplanar geometries with an inverted pyrrole ring tilted away from the porphyrin plane. The bond distances between iron and inner-core C−H for Fe(NCTPP)Br are in the range of an agostic inter…
Dense La 0.4 Sr 0.6 Co 0.2 Fe 0.8 O 3 - δ oxygen-permeable membranes of different thickness were prepared by solid-state reaction. The oxygen flux facilitated by an oxygen partial pressure difference across the oxide membrane was measured at elevated temperatures. It is revealed that oxygen permeation flux is entirely…
The Fermi-surface topology of the organic superconductor λ-(BETS) 2 GaCl 4 has been determined using the Shubnikov-de Haas and magnetic breakdown effects and angle-dependent magnetoresistance oscillations. The former experiments were carried out in pulsed fields of up to 60 T, whereas the latter employed quasistatic f…
An in situ x-ray diffraction study was conducted to study the pressure-induced phase transformation in nanocrystalline anatase/rutile (TiO 2 ) to 35.1 GPa. The nano-anatase phase remains stable to approximately 16.4 GPa, and then transforms to an amorphous phase, which is returned upon release of pressure. The nano-ru…
Effects of calcination treatment on samples of mono-metallic Pd and Pd 77 -Ag 23 alloy with primary particles around 8 nm were studied with the temperature-programmed reduction technique. Temperature profiles of hydrogen consumption for calcined samples from a stream of 10% H 2 in N 2 were monitored by a thermal condu…
We present a photoemission and x-ray-absorption study of the misfit-layered (Bi,Pb)-Sr-Co-O compounds which have a Co-O triangular lattice with a mixed valence of ${\mathrm{Co}}^{3+}$ and ${\mathrm{Co}}^{4+}.$ The valence-band photoemission as well as the $\mathrm{O}1s$ and $\mathrm{Co}2p$ x-ray absorption spectra ind…
The unprecedented structural behavior of Co(3)(dipyridylamide)(4)Cl(2), characterized in two crystalline forms in which the tricobalt framework is either symmetric or highly nonsymmetric at room temperature is investigated by means of gradient-corrected DFT calculations. The isolated molecule is assigned a single ener…
A well-defined biodegradable block copolymer (PCL- b -PLLA, M n = 1.72 × 10 4, M w / M n = 1.37) of poly(ε-caprolactone) (PCL) and poly( l -lactide) (PLLA) was synthesized by a two-step ring-opening polymerization of ε-caprolactone and l -lactide. Furthermore, we found that α-cyclodextrin (α-CD) molecules may simultan…
An orthogonal, convergent route for the introduction of substoichiometric numbers of latent surface sites into dendrimers based on melamine is used to prepare targets that display one or two Boc-protected amines on the periphery. Asymmetry is the result of the stepwise incorporation of functionalized and unfunctionali…