Materials Literature
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The energy level schemes of four rare-earth dopants (Ce 3+ , Nd 3+ , Dy 3+ , and Er 3+ ) in BaY 2 F 8 , as determined by optical absorption spectra, were fitted with a single-ion Hamiltonian and analysed within Newman's Superposition Model for the crystal field. A unified picture for the four dopants was obtained, by…
Here we investigate the dynamics of a gas bubble rising through an inclined channel in two dimensions. The fluids obey the Stokes equations and a boundary integral method is used to solve for the dynamics of the bubbles. Bubbles with and without an insoluble surfactant are considered. We study the dynamics of the bubb…
The microphase-separated morphology of a melt of a specific class of comb−coil diblock copolymers, consisting of an AB comb block and a linear homopolymer A block, is analyzed in the weak segregation limit. On increasing the length of the homopolymer A block, the systems go through a characteristic series of structura…
We report the self-formation of nanometer-size silicon islands on a silicon-on-insulator (SOI) substrate that is associated with simple thermal treatment in the range of 500–900 °C. We study the island formation process versus the temperature of the thermal annealing, the thickness of the top silicon layer, and the pr…
High-quality ZnO () epitaxial films have been grown on sapphire () substrate by atmospheric pressure MOCVD method using zinc acetylacetonate (Zn(C5H7O2)2) and oxygen. The crystallinity of the ZnO films was considerably improved with increasing the film thickness. The full width at half maximum (FWHM) obtained from the…
The inelastic behavior of concrete for highly nonproportional loading paths with rotating principal stress axes is studied. Test cylinders are first loaded in compression under uniaxial stress and then torsion is applied at constant axial displacement. Proportional compressive-torsional loading tests are also carried…
Natural Na-montmorillonite (MMT) with the formula (Na0.67K0.01Ca0.02)(Al2.90Mg0.59 Fe3+ 0.49Ti0.01)(Si7.92Al0.08)O20(OH)4was intercalated with octadecylamine (C18H39N) (ODA) with varied MMT/ODA ratios. The basal spacings d(00l) of natural and intercalated Na-MMT with ODA were determined by XRD analysis. The set of bas…
The isothermal oxidation behaviour of two phase (α + β) titanium base alloy Ti6Al4V (coupons) has been studied at 1050, 1150, 1250, and 1340 K in O2 gas at atmospheric pressure for 2, 4, 6, 8, and 12 h. Investigations on kinetic behaviour followed by the metallographic examination of oxidised scale morphology was carr…
p-Type cupric oxide has been deposited electrochemically on platinum and gold electrodes from Cu(II) solutions containing various amino acids, which is very attractive because the procedure is simple and the preparation of large-area film is possible. This indicates that the anodic deposition of CuO takes place simult…
Multiwall nanotubes were functionalized using plasma treatments, chemical oxidation, ball milling and thermal treatments. In optimized conditions, plasmas modify nanotubes surface chemistry with a great selectivity. Vickers microindentation and tension tests performed on epoxy resin loaded with multiwall nanotubes all…
We report a quantum mechanical study on the complexes of lanthanide cations M3+ with bifunctional ligands L (denoted AcA, AccA, AcP, AccP, PcP and PccP) bearing amide “A” and/or phosphoryl “P” groups separated by one “c” or two “cc” CH2 connectors. The main aims are to (i) assess how strong is the chelate effect (i.e.…
A complete set of elastic, dielectric and piezoelectric coefficients for the domain engineered 0.70Pb(Mg1/3Nb2/3)O3‐0.30PbTiO3 [PMN‐30%PT] single crystal was measured by a hybrid method combining ultrasonic and resonance techniques. At room temperature, the PMN‐30%PT single crystal has rhombohedral symmetry. After bei…
We study numerically and analytically a simple off-lattice model of scalar harmonic vibrations by means of Euclidean random matrix theory. Since the spectrum of this model shares the most puzzling spectral features with the high-frequency domain of glasses (non-Rayleigh broadening of the Brillouin peak, boson peak and…
Polycrystalline samples of La4LiMnO8 and La3SrLiMnO8 have been studied by a combination of X-ray diffraction (XRD), neutron diffraction (ND), 6Li MAS NMR, electron microscopy (EM), and magnetometry. Room-temperature XRD and ND measurements suggest that both compounds have the K2NiF4 structure, with a disordered arrang…
Anomalous x-ray scattering experiments on glassy Ge
The titanium oxo-organo clusters [Ti16O16(OEt)32] are used as precondensed building blocks for the sol-gel synthesis of titanium oxide nanostructures in the presence of an amphiphilic block copolymer PS-b-PMAA (PS = polystyrene block; PMAA = polymethacrylic acid block) as a structure directing agent. It is shown that…
Simple reactions between Re(CO)5Cl and 2-benzoxazol-2-ylphenol, 2-benzothiazol-2-ylphenol or 2-(1-methyl-1H- benzoimidazol-2-yl)phenol (performed in boiling toluene) lead to dimeric complexes of general formula Re2(CO)6(N∩O−)2. The obtained dimeric species are quite stable in non-coordinating solvents, but in coordina…
The atom positions in the structure of the R-phase in a TiNi(Fe) intermetallic compound have been refined using the multi-slice least-squares method based on electron diffraction data obtained from 50 nm sized regions in a CM30 FEG TEM instrument. The refinement accounted for dynamic scattering including the specimen…
Two homologous series of phenylisoxazoles derived from 3-[4-(4-trans-n-heptylcyclohexyl]-5-(4-alkoxyphenyl)isoxazole and 3-[4-(4-trans-n-heptylcyclohexyl)phenyl]-5-(5-n-alkylthiophene)isoxazole have been synthesized. The liquid crystal compounds obtained were characterized by NMR, differential scanning calorimetry (DS…
Slow diffusion of aqueous solutions of europium(III) chloride into gel of sodium metasilicate containing malonic acid (H2mal) yields single crystals of the three-dimensional compound of formula [Eu2(mal)3(H2O)6] whose structure was determined by X-ray diffraction methods at 293 and 173 K. It crystallizes in the monocl…