Materials Literature
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Relaxation schemes for finding normal modes of nonlinear excitations are described, and applied to the vortex-spinwave scattering problem in classical two-dimensional easy-plane Heisenberg models. The schemes employ the square of an effective Hamiltonian to ensure positive eigenvalues, together with an evolution in ti…
The Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) will be a Day-One instrument of the Spanish 10.4 m telescope Gran Telescopio Canarias, whose first light is planned for 2002. GTC will be installed at the Observatorio del Roque de los Muchachos in La Palma, Spain. OSIRIS three primary…
From the order-N electronic-structure formulation, a Hamiltonian is derived, of which lowest eigen state is the generalized or composite-band Wannier state. This Hamiltonian maps the locality of the Wannier state to that of a virtual impurity state and to a perturbation from a bonding orbital. These theories are demon…
The reflection properties of 300 nm periodically structured silicon surfaces with depth varying between 35 and 190 nm, prepared by interference lithography, were examined in the range 200 nm<λ<3000 nm. A decrease in the reflectivity that becomes stronger with increasing structure depth is observed below 1000 nm. This…
Siting of copper ions in Cu I −Y zeolite, prepared by gas-phase exchange of NH 4 −Y with CuCl, has been investigated employing XRPD, XAS and IR spectroscopies. An X-ray powder diffraction study of the zeolite in a vacuum shows that 23.4(2) cuprous ions are located at site I*, 6.1(3) at site II, and 11.5(3) at site II*…
Nanostructured ZnFe 2 O 4 ferrites with different grain sizes were prepared by high energy ball milling for various milling times. Both the average grain size and the root mean square strain were estimated from the x-ray diffraction line broadening. The lattice parameter initially decreases slightly with milling and i…
The ${\mathrm{Cu}}_{2}\mathrm{O}$ film is epitaxially grown on air-cleaved MgO(001) by dc-reactive magnetron sputtering. From the reflection high-energy electron diffraction patterns two orientations are identified: (I) ${\mathrm{Cu}}_{2}\mathrm{O}(001)\ensuremath{\Vert}\mathrm{MgO}(001)$ and ${\mathrm{Cu}}_{2}\mathrm…
Oil and gas pipelines often display a bulk magnetic easy magnetization direction, and this may influence results obtained during magnetic nondestructive evaluation. The origin of this magnetic easy axis is not well known. Earlier work [L. Clapham, C. Heald, T. Krause, and D. L. Atherton, J. Appl. Phys. 86, 1574 (1999)…
In situ crystalline lead zirconate (PZ) thin films were deposited on platinum metallized silicon substrates, using a 248 nm KrF pulsed excimer laser ablation technique. The antiferroelectricity in PZ thin films was confirmed by means of P vs E and C vs V measurements. The maximum observed saturated polarization (Ps) w…
We present a spectroscopic ellipsometry study of the optical anisotropies at energies above and below a crossing point at $\ensuremath{\approx}2$ eV in the optical conductivity of ${\mathrm{Bi}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ crystals. Below ${T}_{\mathrm{co}},$ we observe a sudden increase of…
The ferromagnetic oxide ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CoO}}_{3}$ has been studied by magnetic circular x-ray dichroism (MCXD) in core-level absorption. In the Co ${2p}_{3/2,1/2}$ absorption, the orbital and spin magnetic moments of the Co $3d$ are deduced with the use of magneto-optical su…
We have investigated the electronic structure and chemical bonding of Al2C2 and Al2C2− both experimentally and theoretically. Photoelectron spectra of Al2C2− were obtained at several photon energies. Two anionic isomers were observed: one with a very sharp ground state feature and a low vertical electron binding energ…
We study theoretically the multicritical phenomena of the superconductivity (SC) and antiferromagnetism (AF) in organic conductors $\kappa$-BEDT salts. The phase diagram and the experimental data on the NMR relaxation rate $1/T_1$ is analysed in terms of the renormalization group method. The bicritical phenomenon obse…
In this communication we address two issues essential for low-voltage memory applications of ferroelectric thin films: the size effect on polarization switching, and polarization fatigue. According to the proposed concept, both of these phenomena are controlled by local injection of charge into the interfacial layers…
This article reports a process for preparing nanocrystalline diamond films by ion bombardment of different energies induced by applying a negative substrate bias voltage in microwave plasma-assisted chemical-vapor-deposition. The dependencies of the film morphology, grain size, growth rate, and average surface roughne…
In this study, we have cloned the ankB gene, encoding an ankyrin-like protein in Pseudomonas aeruginosa. The ankB gene is composed of 549 bp encoding a protein of 183 amino acids that possesses four 33-amino-acid ankyrin repeats that are a hallmark of erythrocyte and brain ankyrins. The location of ankB is 57 bp downs…
Theoretical study on the effect of high Fe spin S =5/2 on the organic two-dimensional electronic system of BETS compounds is made by the calculation with the mean-field approximation for the Coulomb interaction. It turned out that a relatively smaller value of on-site Coulomb interaction, U = U BETS , on BETS sites co…
Most of the works devoted so far to the electronic band structure of multiwall nanotubes have been restricted to the case in which the individual layers have the same chirality. By comparison, much less is known on the electronic properties of multiwall nanotubes that mix different chiralities. These are interesting s…
Two-dimensional channelling patterns, derived from variations in characteristic X-ray emission rates as a function of incident electron beam orientation, have been recorded from an Al 72 Ni 20 Co 8 decagonal quasicrystal for the first time. These channelling patterns indicate that the Al and transition metal atoms occ…
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