Materials Literature
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TiO 2 films cast on conducting glass plates were modified by adsorbing gold nanoparticles (5 nm diameter) from a toluene solution. Selective formation of Au islands and larger particles on the TiO 2 surface could be seen from transmission electron micrographs and AFM images. Although the adsorbed Au particles are larg…
Poly(vinyl alcohol)/sodium montmorillonite nanocomposites of various compositions were created by casting from a polymer/silicate water suspension. The composite structure study revealed a coexistence of exfoliated and intercalated MMT layers, especially for low and moderate silicate loadings. The inorganic layers pro…
The two-photon absorption (TPA) coefficient (β) and third-order nonlinear optical susceptibility (χ ⟨3⟩ ) of Zn 1- x Ag x Se ( x = 0.08,0.10,0.20) crystals were investigated using the transmission and degenerate four-wave mixing methods. The experimental results show that the real and imaginary parts of the third-orde…
Carbonated hydroxyapatites (HAPCO 3 Na) and fluoroapatites (FAPCO 3 Na) containing sodium ions have been precipitated by the hydrothermal method. The effect of carbonate and sodium substituted for phosphate and calcium respectively on the dipolar mobility of the OH - and F - ions located inside the apatitic channels o…
We have grown heteroepitaxial thin film structures composed of various transition metal oxides such as the colossal magnetoresistance manganites, superconducting cuprates, ruthenates as well as insulating titanates on SrTiO<SUB>3</SUB>, NdGaO<SUB>3</SUB> and LaAlO<SUB>3</SUB> substrates using a UHV laser molecular bea…
Summary Vanillyl and veratryl alcohols were used as monomeric lignin model compounds in experiments aiming to enhance the understanding of the lignin oxidation mechanisms involved in the oxygen delignification in acidic media catalysed by [PMo 7 V 5 O 40 ] 8− (HPA-5) heteropolyanion. Based on the model compound experi…
A new disk-shaped amphiphilic dendrimer has been synthesized by attaching sixty-four 12-hydroxydodecanoic acid chains to a fourth generation poly(amido amine) (PAMAM) dendrimer core. Surface pressure and surface potential−area isotherm measurements have shown that the dendrimer forms a stable monolayer at the air/wate…
In this paper we present embedded-cluster calculations on singly charged and neutral oxygen vacancies (or F centres) in the oxide perovskite BaTiO 3 . The simulations include Hartree-Fock theory with MP2 corrections and density-functional-theory calculations for a central quantum defect cluster and a pair-potential de…
The synthesis of new ferrocene derivatives bearing phenoxy and/or formyl groups allows one to obtain phosphorus-containing dendrimers with ferrocene units at the core, within the branches, and at the periphery. Dendrimers with a ferrocene at the core were built from 1,1‘-ferrocenedicarboxaldehyde up to the fourth gene…
The metathesis reaction of K 4 Ge 4 Se 10 with various alkyl tri- and dimethylammonium halides [C n H 2 n +1 N(CH 3 ) 3 - m H m ]X ( n = 8, 9, 10, 12, 14, 16, 18; m = 0, 1; X = Cl, Br) led to several new surfactant−inorganic template phases containing selenogermanate adamantane units [Ge 4 Se 10 ]. 4 - The crystal str…
A technique for using rheological information to determine the level of long chain branching in polyethylenes produced using a constrained geometry catalyst and having low levels of branching is described. The complex viscosity as a function of frequency is used, along with a molecular weight distribution (MWD) determ…
On the basis of data from a combination of X-ray diffraction techniques, the B O morph of hexatriacontane [H(CH 2 ) 36 H], a low-molecular-mass gelator of several classes of liquids (including shorter n -alkanes), has been identified unambiguously as the molecular packing arrangement within the microplatelet units of…
Room temperature x-ray diffraction, magnetization and neutron diffraction measurements up to 500 K have been carried out on polycrystalline bulk double perovskites AA'FeMoO 6 (AA' = Ba 2 , BaSr, Sr 2 , Ca 2 ) in order to determine and correlate their structural and magnetic properties. As the average ionic radius is d…
Organometallic- and organic-based materials exhibiting the technologically important property of bulk magnetism have been designed, prepared, and studied. These magnets are prepared via conventional organic chemistry methodologies and unlike conventional inorganic-based magnets do not require metallurgical processing.…
The symmetry implantation in the tight-binding method is analysed. A transparent algorithm is proposed to calculate eigenvalues and eigenvectors with automatic assignation by the complete set of conserved quantum numbers. For crystals, the energy bands are obtained with no summation over the lattice, while the eigenve…
Developments of single crystal ED patterns in melt-crystallized poly(trimethylene terephthalate) (PTT) have been successfully achieved. Five different zonal electron diffraction patterns containing a total of 14 independent reflections were obtained. The PTT structure under strain-free conditions was identified as a t…
Boron arsenide, the typically-ignored member of the III-V arsenide series BAs-AlAs-GaAs-InAs is found to resemble silicon electronically: its Gamma conduction band minimum is p-like (Gamma_15), not s-like (Gamma_1c), it has an X_1c-like indirect band gap, and its bond charge is distributed almost equally on the two at…
Pr 0.5 Ca 0.5 Mn 0.99 Cr 0.01 O 3 shows several anomalous properties: Field-cooled (FC) resistivity at 10 K is several orders of magnitude lower than the zero-field cooled (ZFC) value, magnetoresistance isotherm at 125 K is asymmetric about the origin (H=0 T) and resistivity and magnetization are hysteretic between fi…
The giant intrinsic hysteresis as a function of hydrogen concentration $x$ in the optical and electrical properties of the archetypal switchable mirror ${\mathrm{YH}}_{x}$ is eliminated by alloying Y with the chemically similar La. The ${\mathrm{La}}_{1\ensuremath{-}z}{\mathrm{Y}}_{z}{\mathrm{H}}_{x}$ films with $z\en…
The microstructure of polycrystalline ZnO thin films grown on amorphous fused quartz has been studied by transmission electron microscopy and electron energy loss spectroscopy (EELS). The optical functions of the grain and grain boundary of ZnO acquired from EELS are compared to elucidate the mechanism of the formatio…