Materials Literature
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The coupling between electrons and phonons plays important roles in physics, chemistry and biology. However, the accurate calculation of the electron-phonon coupling constants is computationally expensive as it involves solving the Schrodinger equation for O(N) nuclear configurations, where N is the number of nuclei.…
Reversible addition−fragmentation chain transfer polymerization was applied to the synthesis of well-defined diblock glycopolymers carrying different cyclic carbohydrates on the two blocks. The macroRAFT agents poly(methyl 6- O -methacryloyl-α- d -glucoside) dithiobenzoate and poly(2-methacryloxyethyl glucoside) dithi…
Pyrochlore-type yttrium stannate (Y 2 Sn 2 O 7 ) doped with trivalent europium ions (Eu 3+ ) was synthesized as thin films by the sol−gel method. X-ray diffractometry, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy were used to evaluate the crystallinity and purity of the films,…
The synthesis of a block codendrimer (g3-PBE-b-g3-PMDC), composed of a third-generation poly(benzyl ether) (PBE) monodendron and an aliphatic polyether (PMDC) monodendron is reported. In THF/diiospropyl ether (1:1) the PMDC block functions as a "hydrophilic" block, while the PBE acts as a "hydrophobic" block. The code…
The effect of temperature on the buildup of polyelectrolyte multilayers consisting of poly(styrenesulfonate) (PSS), poly(diallyldimethylammonium) (PDADMA), and poly(allylamine) (PAH) was studied by using a quartz crystal microbalance. The increase of temperature in the deposition process was shown to have a considerab…
The aim of this work was to compare and explore electron microscopy and atomic force microscopy (AFM) for structure determination of cellulose whiskers and their nanocomposite with poly(lactic acid). From conventional bright-field transmission electron microscopy (TEM) it was possible to identify individual whiskers,…
Boron-dipyrrin chromophores containing a 5-aryl group with or without internal steric hindrance toward aryl rotation have been synthesized and then characterized via X-ray diffraction, static and time-resolved optical spectroscopy, and theory. Compounds with a 5-phenyl or 5-(4-tert-butylphenyl) group show low fluoresc…
We demonstrate a convenient and cost-effective chemical approach for fabricating highly ordered Au nanoparticle arrays with sub-10-nm interparticle gaps. Near-field enhancements inside the interparticle gaps create uniform periodic arrays of well-defined "hot spots" exploitable for large surface-enhanced Raman spectro…
Abstract The correlation of TEM imaging and micro‐photoluminescence studies of electron irradiated areas of diamond, developed in Bristol, has been extended to new optical centres and defects. In this paper, we show new evidence of the interaction of point defects with dislocations and grain boundaries in diamond. Opt…
A theoretical approach to the crystalline-to-amorphous phase transformation during self-irradiation is proposed. The different stages of the amorphization process (metamictization) are shown to correspond to internally stressed equilibrium states, associated with the minima of a free-energy functional, in which the el…
The rheological behaviors of polymer brush under oscillatory shear flow were investigated by nonequilibrium Monte Carlo simulation. The grafted chain under oscillatory shear flow exhibited a waggling behavior like a flower, and the segments were found to have different oscillatory phases along the chain contour. Stres…
The influence of defects in nanograins, e.g. stacking faults and twinnings, on mechanical properties of nanocrystalline materials is studied by molecular dynamics simulations. Two types of many-body interatomic potential based on aluminium are adopted to investigate the influence of stacking fault energy on the deform…
The self- and mutual diffusion coefficients for binary mixtures of Ar-Kr both in the bulk and in the nanopores were studied by molecular dynamics simulations. The composition dependences and the relationships between the self- and the mutual diffusion coefficients both in the bulk and in the nanopores were further dis…
The Sso10b (or Alba) family of proteins is a conserved group of archaeal and eukaryotic proteins which are thought to play a role in both chromatin organization and RNA metabolism. We describe here the solution structure and properties of Sso10b2 from Sulfolobus solfataricus. NMR data including residual dipolar coupli…
The effects of Ti, B and O co-segregating on the α-Fe Σ5 [001] / (010) grain boundary are studied by a first-principles method, DMol. We found that (Ti+B) acts as an enhancer, but O can completely offset the beneficial effect of Ti. Based on the segregation energy analysis, it is also found that Ti can effectively pro…
YMnO 3 exhibits a ferroelectric transition at high temperature (≈900 K) and magnetic ordering at T N ≈70 K, where the dielectric constant shows an anomaly indicative of the magneto-dielectric effect. Here we report powder neutron diffraction experiments in this compound that show that the magnetic moment at saturation…
We demonstrate the synthesis of single-crystalline star-shaped ZnO microcrystals with six arms by a simple solution method. Microscopic and diffraction data reveal that the as-grown products have a wurtzite structure. Each arm of the ZnO microstars has a sharp tip of several nanometers. Under moderate optical excitati…
The physical origins of negative refractive index are derived from a dilute microscopic model, producing a result that is generalized to the dense condensed phase limit. In particular, scattering from a thin sheet of electric and magnetic dipoles driven above resonance is used to form a fundamental description for neg…
Crystallographic and magnetic properties of Co 2 Mn 1− x Fe x Sn and Co 2 Mn 1− y Cr y Sn Heusler alloys were studied using x-ray diffraction, scanning electron microscopy with energy dispersive x-ray analysis, magnetization measurements and Mössbauer spectroscopy. We found that the intermetallic compounds crystallize…
Ultrasmall P450scc cytochrome microcrystals are grown by classical hanging vapor diffusion and by its modification using homologous protein thin-film template displaying a long-range order. The nucleation and growth mechanisms of P450scc microcrystals are studied at the thin cytochrome film surface by a new microbeam…