Materials Literature
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Abstract We examine some of the structural aspects that influence the mesomorphic behavior of liquid‐crystalline dimeric epoxy resins with imine groups in the mesogens. We synthesized two new series of monomers and compared them with previously synthesized monomers. Compared with previously studied series, the imine g…
We have investigated the electrical transport properties through crossed nanotube junction between two metallic single-walled carbon nanotubes. Depending on the temperature range, the crossed junction exhibits different behaviors. At high temperatures, the crossed junction acts as a tunneling junction and its conducta…
Magnetic properties, phase evolution and aftereffect of melt-spun Pr10Fe90−xBx (x=5.88–11.5) nanocomposite ribbons have been studied. Summarizing the results of thermal magnetic analysis and Mössbauer spectroscopy, two phases, namely Pr2Fe14B and α-Fe, were found for ribbons with x=5.88 and 7.5, while additional two m…
Thick (1–14 μm) films of ferrimagnetic barium hexaferrite (BaFe12O19 or BaM) having the c-axis ([0001]) in the film plane were deposited by pulsed laser deposition onto a-plane (112¯0) sapphire (Al2O3) substrates, and were found to have a (101¯0) orientation. Torque and magnetization measurements show these films are…
Bismuth-bearing tetrahedrite and tennanite were synthesized from dry runs in evacuated silica glass tubes at 350 °C, 450 °C and 520 °C, and studied by means of microprobe analyses on polished sections and X-ray powder diffraction. Charges were prepared with two Zn or Fe atoms p.f.u., with pure As, resp. Sb, or with As…
The Young’s modulus and helium gas permeability of vapor-deposited poly(4,4′-oxydiphenylenepyromellitimide) were measured at cryogenic and elevated temperatures (10–573 K). The Young’s modulus decreased with increasing temperature from 5.5 GPa at 10 K to 1.8 GPa at 573 K. The temperature dependency of the permeability…
Laser annealing has been employed to decompose half-metallic CrO2 into insulating Cr2O3 in air ambient. While both Cr2O3 and CrO2 are present, the relative fraction of each phase was controlled by changing the duration and power of laser irradiation. Glancing angle x-ray diffraction and micro-Raman scattering were use…
A molecular tetrad consisting of a free base porphyrin (P) linked to a triquinone moiety consisting of a naphthoquinone bearing two benzoquinones (NQ−BQ 2 ) has been synthesized and its photochemistry has been investigated using time-resolved spectroscopic techniques. Excitation of the porphyrin chromophore of the P−N…
Pd particles were inserted into polythiophene (PT) films and studied for the activity for the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) in acid media. In situ X-ray absorption spectroscopy (XAS) was employed for the characterization of the Pd particles and the results confirmed that they po…
[reaction: see text] Thiol-disulfide exchange can be used to prepare multivalent conjugates of a small molecule or octapeptide displayed on dendrimers based on melamine. Exchange of four or eight thiopyridyl groups by captopril occurs at room temperature in methanol almost quantitatively. Exchange using the peptide re…
Electromigration (EM) reliability was investigated for Cu/porous low k interconnects. The porous low k dielectric was a methylsilsesquioxane (MSQ) based spin-on organosilicate material with k of 2.2. The activation energy for EM failure was found to be about 0.9 eV for Cu/porous MSQ between 208 and 367 °C, which is co…
Damaged structures of α-SiC below and above the critical temperature of amorphization (Tc) under high-energy electron irradiation were studied by means of transmission electron microscopy and electron energy-loss spectroscopy. Above Tc, crystal fragmentation takes place due to local lattice strains caused by preferent…
A finite difference simulation of a causally excited electromagnetic Gaussian beam incident on an interface between free space and a physically realizable negative refractive index material shows that negative refraction of finite beams does occur. A discontinuity in the phase normal direction is established very quic…
Abstract The preparation and properties of poly(1‐butene) (PB)/clay nanocomposites are described for the first time. Nanocomposites were prepared with the melt‐intercalation technique, using organically modified clay. The X‐ray diffraction patterns portrayed well‐defined diffraction peaks at higher d ‐spacing than pri…
[reaction: see text] Following the discovery that meso-substituted corroles are formed in solvent-free condensation of pyrrole with aldehydes, we demonstrate that a small variation in the methodology is suitable for facile synthesis of cobalt(III) corrole and hexaphyrin. These compounds, as well as three noncyclic pro…
The switching current profiles of ferroelectric Pt/Pb(Zr0.4Ti0.6)O3/Pt capacitors were investigated after high-temperature baking to elucidate the mechanisms for retention loss. In the same-state retention, a decrease in the peak value of switching current and increase in the switching time were observed. These change…
To determine the relative stability of alpha and beta rotational isomers of the Wells-Dawson structure, the energies of some fully oxidized, single- and 2-fold-reduced systems were calculated by means of DFT calculations. The thermodynamics of the alpha/beta equilibrium for P(2)M(18) Wells-Dawson anions is slightly sh…
IV–VI diluted magnetic semiconductor Ge1−xMnxTe films with various Mn compositions up to x=0.53 were prepared on glass substrates by a rf sputtering method. Magnetic measurements indicate that all the Ge1−xMnxTe films (0.07⩽x⩽053) show ferromagnetic order at low temperatures since hysteretic behavior is clearly observ…
We calculate the low-temperature spectral function of one-dimensional incommensurate charge density wave states and half filled Mott insulators. At T=0 there are two dispersing features associated with the spin and charge degrees of freedom, respectively. We show that already at very low temperatures (compared to the…
Abstract A series of novel mesogen‐jacketed liquid‐crystal polymers, poly[2,5‐bis(4′‐alkoxyphenyl)‐styrene] (P‐ n , n = 1–11), were prepared via free‐radical polymerization of newly synthesized monomers, 2,5‐bis(4′‐alkoxyphenyl)styrene (M‐ n , n = 1–11). The influence of the alkoxy tail length on the liquid‐crystallin…