Materials Literature
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The fabrication of air‐gap structures for electrical interconnections has been demonstrated using a sacrificial polymer encapsulated in conventional dielectric materials. The air‐gap is formed by thermally decomposing the sacrificial polymer and allowing the by‐products to diffuse through the encapsulating dielectric.…
A ${}^{139}\mathrm{La}$ NMR study was carried out on melt-grown samples of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ $(0<~x<~0.15).$ The microscopic magnetic structure of the parent ${\mathrm{LaMnO}}_{3}$ was identified as a homogeneous antiferromagnet at low temperatures. Substituted…
We present dielectric relaxation (DS) and light scattering (LS) data of several glass formers. Relaxational features are compiled which are not yet properly taken into account by current models. (i) We distinguish two types of glass formers. Type A systems do not show a slow -process whereas type B systems do. A full…
A systematic application of intercalation techniques to layered superconducting oxides enables us to open a new chapter in the development of nano-hybrids with various functions. Recently we were successful in preparing a new series of inorganic-inorganic nano-hybrids, M-X-Bi 2 Sr 2 Ca m–1 Cu m O y (M=Hg, Ag, Au; X=Br…
Single-crystal SrZrO 3 with perovskite-type structure was grown by a floating-zone method. The polarized Raman scattering spectra were measured at room temperature. The observed Raman spectra were interpreted on the basis of a factor group analysis for the group D 2h . Although 24 Raman active modes were expected, 15…
Materials that exhibit colossal magnetoresistance (CMR) are currently the focus of an intense research effort, driven by the technological applications that their properties suggest. Using the angular correlation of photons from electron-positron annihilation, we present a first view of the Fermi surface of a material…
Numerical results are presented for the formation of breakdown streamers which bridge a 1 mm gap between a positive 50 µm radius hyperboloid point and a plane, when a dc voltage is applied. The results show that, for such gaps, no streamers form at voltages lower than or equal to 2.5 kV and that streamers bridge the g…
In this study we present theoretical predictions concerning the third-order nonlinear optical properties of semiconductor carbon nanotubes for photon energies well below the fundamental absorption edge. Both virtual interband -electron transitions and combined intraband-interband ones are assumed to be the basic micro…
We consider the effect of quantum spin fluctuations on the ground-state properties of the Heisenberg antiferromagnet on an anisotropic triangular lattice using linear spin-wave (LSW) theory. This model should describe the magnetic properties of the insulating phase of the kappa-(BEDT-TTF)(2)X family of superconducting…
Two different recombinant constructs of the N-terminal domain in Escherichia coli DnaJ were uniformly labeled with nitrogen-15 and carbon-13. One, DnaJ(1-78), contains the complete "J-domain," and the other, DnaJ(1-104), contains both the "J-domain" and a conserved "G/F" extension at the C-terminus. The three-dimensio…
Introduction of high purity alloys improved the corrosion resistance of magnesium alloys significantly. This has led to an increased use of magnesium for components like valve covers, transmission housing, and gear box housing. Because of the unnoble nature of magnesium, galvanic corrosion is the main challenge when m…
Deformation characteristics at elevated temperatures were examined in an AZ31 magnesium alloy. The asreceived bar was extruded for refineing its microstructure. The extruded alloy had equiaxed grains with an average grain size of ∼5 μm. Tensile test revealed that the material exhibited superplasticity. The maximum elo…
The first chlorin–fullerene electron donor–acceptor (DA) compounds have been synthesized. The synthesis produced C-2′ R and S epimers, both of which exhibited atropisomerism regarding the mutual orientation of the fullerene ball and the propionic acid residue of the phytochlorin unit. The atropisomerism arises from th…
Preparation of large crystal MCM-41 has been achieved by using calcined small crystallite MCM-41 as seeds in a multistage synthesis method. The possible formation mechanism is discussed. We believe that the newly discovered method is particularly important in making high quality thin films of mesoporous materials.
Amine-functionalized metalloporphyrins stably fixated on well-defined ultralarge-pore Nb-doped silicates provided excellent catalytic oxidation activity for bulky substrates.
Three factors govern the adhesion properties of hot-melt and pressure-sensitive adhesives: (1) thermodynamic interfacial properties (Dupré adhesion energy); (2) interfacial losses due to specific interactions; and (3) viscoelastic losses in the bulk related to the rheological properties of the adhesive. In the present…
The temperature and compositional dependence of the electrical conductivity of semiconducting strontium vanadate glasses have been reported in the temperature range 80-500 K. It has been observed that the multiphonon assisted hopping model of small polarons in the nonadiabatic regime, which considers the strong intera…
The discovery of X-rays over 100 years ago and the subsequent discovery of X-ray diffraction 17 years later had a profound impact on almost all areas of the physical sciences. Clay Science is no exception. Modern concepts of clays are shaped to a great extent by information obtained from X-ray based techniques. The X-…
Molecular dynamics (MD) simulations of molten were carried out using the polarizable-ion model (PIM) and the rigid-ion model (RIM). In these simulations the Born-Mayer-Huggins potential was employed with the same potential parameters for both models. In the PIM the polarization of the chloride ions was supplemented. A…
The crystallographic and magnetic structures of Fe 0.5 Cu 0.5 Cr 2 S 4 have been examined in order to generate a possible mechanism to explain the CMR behaviour of such spinels. Neutron powder diffraction has revealed that the tetrahedrally coordinated Fe 3+ and Cu + ions are fully ordered, with the magnetic moments o…