Materials Literature
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The aging behavior of colloidal suspensions of laponite, a model synthetic clay, is investigated using light scattering techniques. In order to measure the complete dynamic structure factor as a function of time and of wave vector, we have developed an original optical setup using a multispeckle technique for simple l…
Antisites, carbon substitutionals, and vacancy defects in BN nanotubes have been investigated by first-principles total energy calculations, based on a density functional spin-polarized method. All defects introduce localized energy levels inside the band gap. For some open-shell systems (carbon substitutionals and va…
The reconstruction on Ge(001) surface is locally and reversibly changed between c(4x2) and p(2x2) by controlling the bias voltage of a scanning tunneling microscope (STM) at 80K. It is c(4x2) with the sample bias voltage V_b =< -0.7V. This structure can be kept with V_b =< 0.6V. When V_b is higher than 0.8V during the…
The microstructure and phase transition in relaxor ferroelectric $\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}$ (PMN) and its solid solution with ${\mathrm{PbTiO}}_{3}$ (PT), $\mathrm{PMN}\ensuremath{-}x\mathrm{PT},$ remain to be some of the most puzzling issues of solid-state science. In the pr…
We study the question of existence and uniqueness for the finite temperature Kohn-Sham equations. For finite volumes, a unique soluion is shown to exists if the effective potential satisfies a set of general conditions and the coupling constant is smaller than a certain value. For periodic background potentials, this…
In this article the structural and electronic properties of CeO 2 and Ce 1 - x Zr x O 2 nanoparticles are investigated using time-resolved X-ray diffraction, X-ray absorption near-edge spectroscopy (XANES), and density functional calculations. CeO 2 and Ce 1 - x Zr x O 2 ( x ≤ 0.5) particles in sizes between 4 and 7 n…
Recently, cationic liposomes have been shown to preferentially target the angiogenic endothelium of tumors. It was the aim of our study to investigate the influence of liposomal surface charge on the uptake and kinetics of liposomes into solid tumors and tumor vasculature. Experiments were performed in the amelanotic…
Collapse and rebound of a cavitation bubble near a wall are revisited with modern experimental means. The bubble is generated by the optical breakdown of the liquid when a strong laser pulse is focused into water. Observations are made with high-speed cinematography; framing rates range between several thousand and 10…
It is found that there exist composite media that exhibit strong spatial dispersion even in the very large wavelength limit. This follows from the study of lattices of ideally conducting parallel thin wires (wire media). In fact, our analysis reveals that the description of this medium by means of a local dispersive u…
Preface. Acknowledgements. Electron Spectroscopy: Some Basic Concepts. Electron Spectrometer Design. The Electron Spectrum: Qualitative and Quantitative Interpretation. Compositional Depth Profiling. Applications of Electron Spectroscopy in Materials Science. Comparison of XPS and AES with Other Analytical Techniques.…
Abstract A new polycarboxylate ligand H 5 L has been synthesized by the attachment of five benzoate subunits onto a diethylenetriamine framework. Seven p K a values have been determined by potentiometry, spectrophotometry and NMR spectroscopy as 1.9(2), 2.8(2), 3.87(5), 4.58(6), 4.87(6), 9.19(6) and 11.68(5), the firs…
Abstract In this paper the fundamentals of the asymmetric elasticity theory are used to consider one‐ and two‐dimensional boundary‐value problems: shear deformation of elastic infinite plane layer(plate); torsion of a ring rigidly fixed at the external contour due to rotation of the inner one; deformation of a plane w…
We have demonstrated that a static permittivity of potassium tantalate is dramatically enhanced by band-to-band excitation at low temperatures. A critical behavior has been observed in the relaxation time and the oscillator strength of its Debye-type dispersion. Two models, considering photoinduced mesoscopic clusters…
Measurements of the energy distributions and energy-resolved polarizations of electrons ejected by incident polarized ${\mathrm{He}}^{+}$ ions are used to probe the dynamics of ${\mathrm{He}}^{+}$ ion neutralization at clean Al(100), Au(100), and Cu(100) surfaces for incident ion energies in the range 10--500 eV. The…
This work investigates the photoluminescence (PL) properties of the cubic chloroperovskite NH 4 MnCl 3 . Like in most concentrated materials, the Mn 2+ PL which is located at 2.10 eV at T = 10 K strongly depends on the temperature. Optical absorption (OA), emission, and excitation spectroscopy, as well as lifetime mea…
The molecular dynamics of a side-chain polymer liquid crystal with a poly(methyl acrylate) backbone and a (p-alkoxy-phenyl)-benzoate mesogenic group have been studied in the unaligned state as a function of temperature and pressure using dielectric spectroscopy. Polarizing optical microscopy, differential scanning cal…
Abstract A new adsorbent for heavy metal ions, cys‐chitin, was produced by modifying chitin in THF with L ‐cysteine in the presence of sulfuric acid as a catalyst. Its structure was confirmed by elemental analysis and FTIR spectra analysis. The adsorption properties of cys‐chitin for Cu II , Cd II , Pb II , Zn II , an…
Low temperature (7 K) absorption spectra of polycrystalline sintered ceramic Lu 2 O 3 :Eu 3+ were recorded between 3950 and 50000 cm −1 . There are two different intrinsic Eu 3+ sites, C 2 and S 6 (C 3i ), in this host. A total of 105 crystal-field (CF) energy levels were assigned and fitted to a semiempirical Hamilto…
Patterns and alignment of carbon nanotubes (CNTs) are particularly important for fabricating functional devices such as field emitters, scanning probes, sensors, and nanoelectronics. In this paper, the effects of various metal substrates on CNT growth are studied. Depending on the different growth mechanisms associate…
Using density-functional theory, we calculate the energy and electronic structure of a polyacetylene chain interacting with various carbon nanotubes. We find that polyacetylene chains are weakly attracted exohedrally or endohedrally to nanotubes. The equilibrium separation between the chain and the wall is close to 3.…