Materials Literature
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The authors first calculate a standard 'linear muffin-tin orbital' band structure (including combined correction and exchange correlation) for TiO 2 compounds in rutile structure. The outcoming bands, especially the last valence (mostly O 2p states) and first conduction (mostly Ti t 2g states) bands, are fairly hybrid…
We report a first observation of the remarkably low electrical resistivity of copper germanide thin films formed at temperatures below 200 °C. At these low temperatures, the ε-Cu3Ge phase with a monoclinic crystal structure is formed, with room-temperature resistivity which can be as low as 5.5 μΩ cm. The films are el…
This paper reports optical absorption and luminescence studies of Cr3+-doped silicate glasses with compositions chosen to vary the octahedral crystal-field splitting at the Cr3+ site. The extensive site-to-site disorder in the glasses is signalled by the inhomogeneous broadening of radiative transitions and by non-exp…
We measured third-order, nonlinear optical susceptibility χ(3) for a series of tetrabenzporphyrins in solution in tetrahydrofuran at 532 nm using degenerate four-wave mixing with picosecond pulses and obtained values of molecular second hyperpolarizability 〈γ〉. The corresponding macroscopic χ(3) values calculated for…
Abstract Styrene‐acrylic acid copolymers exhibit miscibility with various aliphatic, crystalline polyamides (e.g., nylon 6, 11, and 12) at 20% acrylic acid content in the copolymer. At 8% acrylic acid, phase separation is observed with the crystalline polyamides. At 14% acrylic acid, partial miscibility is observed wi…
Abstract Na + and Cl ‐ transport across 2.4‐ and 5.2‐μm‐thick polyimide (PI) PMDA/ODA and 7.5‐μm‐thick du Pont Kapton films was studied in a diffusion cell using ion‐selective electrodes. The temperature was 30°C. Diffusion coefficients D m (in cm 2 /s), permeability coefficients P (in cm 2 /s), and distribution coeff…
Abstract The gas transport properties of several simple vinyl and vinylidene polymers are compared to examine the effect of pendant group type (H, CH 3 , F, Cl) and symmetry of placement. The literature contains extensive information about these polymers, which has been critically reviewed to obtain consistent data fo…
Abstract A mathematical model of the melt spinning process that includes crystallization has been used to compute the velocity, diameter, temperature, and birefringence as a function of distance from the spinneret. An improved inversion procedure is described and is shown to give better results for the computed appare…
Abstract We measured thermal conductivities as well as electric conductivities of some composites in several types of dispersion systems. The dispersion state, that is, the ease in forming conductive chains in these composites, was estimated by the characteristic electric conductivities and compared with the thermal c…
The recovery of proteins following denaturation is optimal at low protein concentrations. The decrease in yield at high concentrations has been explained by the kinetic competition of folding and "wrong aggregation". In the present study, the renaturation-reoxidation of hen and turkey egg white lysozyme was used as a…
The Kapitza conductivity (thermal boundary conductivity (TBC)) between two crystals is studied within a simple three-dimensional lattice dynamical model and the role of interface roughness on an atomic scale is investigated. The interface roughness is modelled by a random alloy monolayer A 1-x B x between the two semi…
The phase transformations and structure characteristics of the Al 65 Cu 17.5 Co 17.5 alloy were studied by neutron diffraction. The scheme of Yamamoto and Ishihara (1988) can satisfactorily index the diffraction patterns. The Al-Cu-Co decagonal phase is stable in the temperature range between 973 and 1350 K. At the lo…
We have discovered novel nonlinear dissipative dynamic patterns in nematic liquid crystals under the influence of a continuously rotating magnetic field. We present a state diagram of the soliton structures as a function of field and rotation rate and discuss physical models describing their growths and propagation an…
Lead zirconate titanate films have been fabricated by a dc sputtering technique with a post deposition rapid thermal annealing treatment at 650 °C for 10 s. The films exhibited good structural, dielectric, and ferroelectric properties compared to conventional furnace-annealed films. The measured dielectric constant an…
We have observed a clear series of fine structures superposed on the angular dependence of magnetoresistance in the metallic and magnetic-field-induced spin-density-wave phases in the low-dimensional organic superconductor (TMTSF${)}_{2}$${\mathrm{ClO}}_{4}$. They appear at the field angles whose tangent satisfies a f…
We show that director fluctuations in nematics induce long-range interactions between walls, analogous to van der Waals forces, which are attractive with symmetric boundary conditions, but may become repulsive with mixed ones. They affect the swelling of lamellar phases in a nematic solvent. The same phenomenon takes…
We examine equilibrium phase separation in a grafted polymer layer composed of mutually immiscible chains. Under symmetric melt conditions, we predict that there is a transition to a ``rippled'' phase--a density wave in composition running along the surface. This transition is expected for a molecular weight 2.27 time…
The dependence of the flow stress of high-purity α-iron monocrystals on temperature and strain rate, measured by successive tensile deformations at temperatures between 250 and 340 K and correlated stress-relaxation tests, is analysed by means of Seeger's theory of thermally activated kink-pair formation in screw disl…
A microscopic calculation of the second-order Raman-scattering efficiency of silicon, with special emphasis on the effects of uniaxial stress, is presented. Employing diagrammatic perturbation theory, the scattering efficiency is obtained for incident- and scattered-photon energies either on or off resonance. A numeri…
(I) CdSrP 2 O 7 cristallise dans P2 1 /n avec a=5,414, b=8,615, c=12,878 A, β=90,01°, Z=4; affinement jusqu'a R=6,0%. (I) CdBaP 2 O 7 cristallise dans P1 avec a=5,641, b=7,038, c=7,624 A, α=78,55, β=89,83, γ=86,79°, Z=2; affinement jusqu'a R=6,0%. Ces deux composes existent a l'etat solide comme les dichromates, avec…