Materials Literature
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256 oligomers make up the quaterthiophene library of compounds 1 which was prepared by a combination of parallel and “mix-and-split” syntheses. An automated screening process for the recording of cyclic voltammetric data and subsequent data analysis allowed the development of structure–property relationships on which…
An unusual bonding mode for a porphyrin ligand is seen in the tellurium porphyrin complex prepared by treatment of TeCl4 with dilithio meso-tetra(p-tolyl)porphyrin [Li2(ttp)]. The structure of [Te(ttp)Cl2] (see picture) has a five-coordinate, square-pyramidal geometry involving a distorted tridentate porphyrin ligand…
A La0.7Ca0.3MnO3−δ single crystal was oxygen-plasma treated at 200 °C. Our electrical and magnetic measurements indicate that the oxygen-plasma treatment can be an effective low temperature method of oxygen stoichiometry modification of colossal magnetoresistance manganites. The oxygen plasma is also shown to introduc…
The effective thermal conductivity of four polymeric thin films with distinct molecular morphologies has been measured as a function of film thickness down to 70 Å using a 3ω technique. Comparing to SiO2, the intrinsic thermal conductivity of polymers is about 5–10 times smaller while the interfacial thermal resistanc…
The present work uses Raman spectra to measure residual stresses in Pb(Zr0.53Ti0.47)O3 thin films. Based on thermodynamic analysis, a linear relationship is found between the stress and the square of the Raman frequency in the A1 [transverse optical3 (TO3)] and E [longitudinal optical3 (LO3)] modes. We calibrate the l…
The results reported in this work show that tightly assembled adducts formed by trisubstituted GdIII complexes and a beta-CD multimer (Poly-beta-CD, d.p. ca. 12) may represent very interesting candidates for novel MRI applications wherein a high number of paramagnetic ions endowed with high relaxivity (per GdIII ion)…
Around 100 porphyrin units have been selectively linked at C(6)-O to a cellulose (Avicel). The properties of the metal-free and zincated porphyrin-celluloses 2 and Zn-2 have been determined by optical and electrochemical methods. Circular dichroism indicates a helical arrangement of the porphyrin units and reveals int…
Abstract 2‐(6‐Oxido‐6H‐dibenzo〈c,e〉〈1,2〉oxa‐phosphorin‐6‐yl)1,4‐benzenediol (ODOPB) and bis(3‐dihydroxyphenyl) phenyl phosphate (BHPP) were successfully synthesized and used as reactive flame retardants in o ‐cresol formaldehyde novolac epoxy resin. Because of the rigid, cyclic, side‐chain structure of ODOPB, the resu…
Acetonitrile might not be an “innocent” solvent after all: The monomeric CuII complex [Cu(dmppy)(en)] (see structure) readily cleaves the C−C bond of acetonitrile under ambient conditions. Previously, heterolytic cleavage of the C−C bond of acetonitrile had only been achieved by phosphane complexes of metals in low ox…
Calorimetric, thermal expansion, resistivity, and magnetization measurements in ${\mathrm{La}}_{2/3}({\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{)}_{1/3}{\mathrm{MnO}}_{3}$ samples evidence the existence of a critical tolerance factor t that determines the relevance of lattice effects in mixed-valence manganites…
A chemical synthesis is described in which ZnSe:Cu particles slowly grow to a final size of ∼3.5 nm radius in 4 h reaction time. During particle growth, samples are extracted to study the luminescence as a function of particle size and temperature. Quantum size effects are observed to influence both the ZnSe and the C…
It has been recently predicted that the co-doping of an acceptor (nitrogen) and a donor (aluminum, gallium, indium) in a 2:1 ratio will dope ZnO p-type due to a reduction in the Madelung energy making the nitrogen acceptor energy level more shallow. We have been growing gallium and nitrogen co-doped ZnO films by radic…
Raman signal enhancements in excess of 10(7) can be achieved at near-infrared wavelengths when mid-nanometer sized gold particles self-organize into close-packed planar arrays. These substrates generate stable surface-enhanced Raman scattering which changes dramatically as a function of periodic structure and excitati…
Structural evolutions of PMN/PT10% $({\mathrm{PbMg}}_{0.3}{\mathrm{Nb}}_{0.6}{\mathrm{Ti}}_{0.1}{\mathrm{O}}_{3})$ and PMN $({\mathrm{PbMg}}_{1/3}{\mathrm{Nb}}_{2/3}{\mathrm{O}}_{3})$ are studied and compared using high-resolution x-ray and neutron diffraction. At high temperature, PMN-like diffuse scattering, associa…
In a spirit akin to the sandpile model of self-organized criticality, we present a simple statistical model of the cellular-automaton type which produces an avalanche spectrum similar to the characteristic-earthquake behavior of some seismic faults. This model, that has no parameter, is amenable to an algebraic descri…
The equation of state and the shock Hugoniot of deuterium are calculated using a first-principles approach, for the conditions of the recent shock experiments. We use density functional theory within a classical mapping of the quantum fluids [ Phys. Rev. Letters, {\bf 84}, 959 (2000) ]. The calculated Hugoniot is clos…
We investigate the static and dynamic behaviors of a Br adlayer electrochemically deposited onto single-crystal Ag(100) using an off-lattice model of the adlayer. Unlike previous studies using a lattice-gas model, the off-lattice model allows adparticles to be located at any position within a two-dimensional approxima…
During the fracture of nanocontacts gold spontaneously forms freely suspended chains of atoms, which is not observed for the iso-electronic noble metals Ag and Cu. Au also differs from Ag and Cu in forming reconstructions at its low-index surfaces. Using mechanically controllable break junctions we show that all the 5…
We report on the effects of partial substitution of nickel by palladium on the thermoelectric properties of ZrNiSn-based half-Heusler compounds. It is shown that the substitution of palladium for nickel results in a significant, beneficial reduction of the thermal conductivity. The Seebeck coefficient also decreases,…
The performance of a composite material system is critically controlled by the interfacial characteristics of the reinforcement and the matrix material. Here we report a study on the interfacial characteristics of a carbon nanotube (CNT)-reinforced polystyrene (PS) composite system through molecular mechanics simulati…