Materials Literature
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We present coupled cluster ab initio calculations for the Mg–He and Ca–He van der Waals potential energy curves. Our calculations employ large atom-centred basis sets, diffuse interbond functions and a fully iterative treatment of single, double and triple excitations in the coupled cluster calculation, and also inclu…
Measurements of the specific heat on the system ${\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}(x<~0.10)$ are reported. Particular attention is paid to the effect that doping the parent compound with electrons by substitution of La for Ca has on the magnetic ground state. The high- $(T>40$ K) temperature data reveal that d…
Abstract Surface‐wave propagation along a metamaterial slab with negative permittivity and permeability is analyzed. The dispersion relations are determined for the TM and TE (odd and even) modes. The Brillouin diagrams are drawn and show that, for odd modes after cutoff, there is an initial frequency range for which…
Abstract Liquid‐crystalline (LC) polyesters based on hexanediol or butanediol, dimethyl 4,4′‐biphenyldicarboxylate, and a sugar‐based diol, isosorbide or isomanide, were prepared with conventional melt polymerization. 1 H NMR spectroscopy confirmed that 50 mol % of the charged sugar diol was successfully incorporated…
Density-functional methods are used to analyze the scaling of discrete oligomeric \ensuremath{\pi}-electron conducting molecules towards idealized isolated polymer chains, treated in periodic boundary conditions. The band gaps of a series of conjugated oligomers of incrementally increasing lengths exactly fit a nearly…
We investigate the effect of counterion fluctuations in a single polyelectrolyte brush in the absence of added salt by systematically expanding the counterion free energy about Poisson-Boltzmann mean field theory. We find that for strongly charged brushes, there is a collapse regime in which the brush height decreases…
A new type of the single-molecule magnet [Mn_4 O_3 Cl_4 (O_2 CEt)_3(py)_3] forms dimers. Recent magnetic hysteresis measurements on this single-molecular magnet revealed interesting phenomena: an absence of quantum tunneling at zero magnetic field and tunneling before magnetic field reversal. This is attributed to a s…
We propose a model of transport in thick-film resistors which naturally explains the observed nonuniversal values of the conductance exponent t extracted in the vicinity of the percolation transition. Essential ingredients of the model are the segregated microstructure typical of thick-film resistors and tunneling bet…
This paper concentrates on the degradation characteristics of hydroxyapatite (HA) coatings on orthopaedic Ti-6Al-4V alloy while immersed in Ringer's salt solution, which were investigated by electrochemical impedance spectroscopy. Electrochemical impedance spectroscopy measurements were used to in situ characterize th…
We present an exactly solvable non-linear elastic model of a volume collapse transition in an isotropic solid. Integrity of the lattice through the transition leads to an infinite-range density-density interaction, which drives classical critical behavior. Nucleation is forbidden within a pressure window leading to in…
A model for a Heisenberg antiferromagnet on a pyrochlore lattice with exchange and dipole-dipole interactions is studied via mean-field theory. In treating the dipoles by use of the Ewald method, a soft (critical) mode with a unique ordering wave vector is selected for all strengths of the dipole-dipole coupling. For…
We investigate the electronic properties of nanocrystalline cerium oxide $({\mathrm{CeO}}_{x})$ films, grown by various techniques, and we establish universal relations between them and the film structure, composition, and morphology. The nanocrystalline ${\mathrm{CeO}}_{x}$ films mainly consist of ${\mathrm{CeO}}_{2}…
The phase diagram of surface structures for the model catalyst ${\mathrm{RuO}}_{2}(110)$ in contact with a gas environment of ${\mathrm{O}}_{2}$ and CO is calculated by density-functional theory and atomistic thermodynamics. Adsorption of the reactants is found to depend crucially on temperature and partial pressures…
The static local-field factor (LFF) of the 2-D electron fluid is calculated {\it nonperturbatively} using a mapping to a classical Coulomb fluid $\lbrack$Phys. Rev. Lett., {\bf 87}, 206$\rbrack$. The LFF for the paramagnetic fluid {\it differs markedly} from perturbation theory where a maximum near 2$k_F$ is expected.…
Abstract This paper reports the preparation and characterization of a new aromatic polyazomethine with rotaxane architecture. The complex of β‐cyclodextrin and 1,4‐phenylenediamine was treated with N ‐ n ‐butyl‐3,6‐diformylcarbazole, which is large enough to prevent dethreading. The polycondensation reaction was perfo…
Abstract Poly(butylene terephthalate)‐ co ‐poly(butylene succinate)‐ block ‐poly(ethylene glycol) segmented random copolymers, with poly(butylene succinate) (PBS) molar fraction ( M PBS ) varying from 10 to 60 %, were synthesized through a melt polycondensation process and characterized by means of GPC, NMR, DSC and m…
In this paper, we describe, for the first time, the combination of surface plasmon resonance spectroscopy (SPS) and surface plasmon enhanced photoluminescence spectroscopy (SPPL) with electrochemical techniques for the detection of photoluminescence in poly(3,4-ethylenedioxythiophene) (PEDOT) ultrathin films. The EC-S…
A two-phase model is developed to simulate the decomposition and spatial phase separation (microstructure evolution) during solidification of hypermonotectic alloys. The minority liquid phase, decomposing in morphology of droplets from the parent melt, is treated as the second phase, L 2 , while the parent melt, inclu…
Abstract The flame‐retardant effect of 2‐methyl‐1,2‐oxaphospholan‐5‐one 2‐oxide (OP) and ammonium polyphosphate (APP) in poly(butylene terephthalate) (PBT) was studied by the limiting oxygen index and the UL94 test. A self‐extinguishing formulation (V‐0 rating) was achieved by the addition of 15 wt% APP and 10 wt% OP.…
Nanoscale composites of polyaniline (PANI) and vanadium oxide (V 2 O 5 ) were assembled via the electrostatic layer-by-layer (LBL) technique, with a thickness per bilayer of 2.5 nm. Interactions between PANI and V 2 O 5 are maximized in comparison to the usual xerogel films due to the nanostructured nature of the LBL…