Materials Literature
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Intergrowth Bi4Ti3O12–PbBi4Ti4O15 single crystals were grown, and their dielectric and ferroelectric anisotropy were investigated along the a and c axes. Dielectric measurements revealed that the Curie temperature was 550 °C, which was lower than that of Bi4Ti3O12 (675 °C) and PbBi4Ti4O15 (570 °C). Remanent polarizati…
The optical properties of SrAlF 5 :Pr 3 + are studied. Emission measurements up to 1200 nm under blue-light excitation in the 3 P 2 level reveal a large number of emissions all originating from the 3 P 0 level and the 1 D 2 level. Under vacuum ultraviolet excitation in the 4f 1 5d 1 bands, emission from the 1 S 0 leve…
Small angle x-ray scattering (SAXS) measurements were performed on nanoporous methyl silsesquioxane films that were generated by the incorporation of a sacrificial polymeric component into the matrix and subsequently removed by thermolysis. The average pore radii ranged from 1 to 5 nm over a porosity range of ∼5–50%.…
The nonlinear step-growth copolymerization of a mixture of low- and high-molecular-weight diols, and a low-molecular-weight diisocyanate is addressed using a kinetic−probabilistic model. The kinetic model allows for the calculation of the concentrations of all species. Different reactivities for isocyanate functional…
Effective-medium theories for predicting conditionally averaged velocity field and hydrodynamic transport coefficients of monodisperse suspensions are extended to bidisperse suspensions. The predictions of the theory are shown to agree very well with the results of direct numerical simulations of bidisperse suspension…
We have investigated the effect of complexation of different phosphorus ligands on the stability, solid state structure, and spectroscopic properties (NMR, IR, UV-vis) of a 5,15-diphenyl-substituted ruthenium porphyrin, (MeOH)Ru(II)(CO)(DPP) 2 [DPP = 5,15-bis(3',5'-di-tert-butyl)phenyl-2,8,12,18-tetraethyl-3,7,13,17-t…
A new series of banana-shaped mesogens with ethylene links in the branches and laterally substituted are presented. They form B1, B2, B6 and B7-like phases. The B7-like and B2 phases are not miscible although identical crystallographic structures are deduced from X-ray studies. The switching in the B7-like phase is wi…
Cavitation bubble nucleation following the passage of an extracorporeal shock wave lithotripter pulse is investigated experimentally and numerically. In the experiments two configurations are considered: Free passage of the shock wave, and reflection of the shock wave from a rigid reflector. The nucleation and the ear…
Argon-ion irradiation has been used to form a tunnel barrier in multiwall carbon nanotubes and single quantum dots have been fabricated with this technique. The periodic Coulomb diamonds have been shown at 10 K and the periodic Coulomb oscillations have been observed up to around 80 K.
This paper describes the surface modification of CdSe nanoparticles (NPs) with amphiphilic and flexible poly(amidoamine) (PAMAM) dendrimers carrying different numbers of hydrophobic aliphatic chains. Although hydrophilic full generation dendrimers with primary amine termini caused aggregation of the CdSe particles, th…
The high-frequency permittivity of composites consisting of a lattice of ferromagnetic wires is investigated. Experimental results using free space or coaxial line microwave measurements are reported. It is shown that the dielectric response is strongly dependent on the magnetic properties of the wires. Negative real…
We present an analysis of the distribution of end groups within a urea-functionalized poly(propyleneamine) dendrimer of the fourth generation by small-angle neutron scattering (SANS). The phenyl end groups have been deuterated to enhance their contrast. The SANS experiments are performed using solution of the labeled…
Three octahedral complexes containing a (cis-cyclam)iron(III) moiety and an O,N-coordinated o-iminobenzosemiquinonate pi radical anion have been synthesized and characterized by X-ray crystallography at 100 K: [Fe(cis-cyclam)(L(1-3)(ISQ))](PF(6))(2) (1-3), where (L(1-3)(ISQ)) represents the monoanionic pi radicals der…
A study of the crystallographic and magnetic structure of the double perovskites Sr 2 MnMoO 6 , Sr 2 MnWO 6 and Ca 2 MnWO 6 has been carried out on polycrystalline samples using neutron powder diffraction (NPD) data. A room temperature analysis of high-resolution NPD patterns has shown that these compounds crystallize…
A technique (laser deposition of Zn/W multilayers) for producing stable nanocrystalline (nc) Zn films free of undesirable imperfections down to a grain size of d=6 nm is presented. These films exhibited grain size softening (inverse Hall–Petch effect) for d⩽11 nm, providing support that this can be a real phenomenon i…
Monte Carlo simulations using a three-dimensional lattice model studied the Ruderman–Kittel–Kasuya–Yosida (RKKY) indirect exchange interaction of doped magnetic Co ions in ZnO films. The results of the calculations show that the RKKY interaction in Co-doped ZnO is long ranged and its magnitude is proportional to R−1 (…
The small-amplitude radial oscillations of a gas microbubble encapsulated by a viscoelastic solid shell and surrounded by a slightly compressible viscoelastic liquid are studied theoretically. The Kelvin–Voigt and 4-constant Oldroyd models are used to describe the viscoelastic properties of the shell and liquid, respe…
The dielectric behaviour of Ba(Ti 1−y Ce y )O 3 solid solutions ( y = 0–0.3) has been studied. A small amount of Ce doping ( y = 0.02) has weak influence on the dielectric behaviour of Ba(Ti 1−y Ce y )O 3 . With increasing Ce concentration, three phase transitions of pure BaTiO 3 are pinched into one rounded dielectri…
The synthesis and photochemistry of a new photolabile protecting group for carboxylic acids based on 8-bromo-7-hydroxyquinoline (BHQ) is described. BHQ possesses a greater single photon quantum efficiency than 4,5-dimethoxy-4-nitrobenzyl ester (DMNB) and 6-bromo-7-hydroxycoumarin-4-ylmethyl (Bhc), and it has sufficien…
We investigated carbon nanotube growth by means of methane chemical vapor deposition on ultrafine silicon patterns prepared by synchrotron-radiation lithography. Grown nanotubes formed suspended bridges between pillars when pillar spacing was comparable to pillar height. Network-like interconnections were obtained on…