Materials Literature
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We present the first analysis of high-resolution x-ray-diffraction spectra of finite-size Thue-Morse GaAs-AlAs superlattice heterostructures, which show essential properties of singular continuous measures. The implications for future investigations of disordered systems are considered.
The elastic strain in Al-0.5% Cu metal lines under silicon nitride passivation has been determined by x-ray diffraction. The experimental stress tensor calculated from these strain values is in excellent agreement with the results of a finite element model calculation. The intrinsic stress in the dielectric plays no r…
We have measured the electron energy-loss spectrum (EELS) of BC3 at sub-eV resolution. Important differences between the total density of states of BC3 at the threshold of the K edge, predicted by earlier ab initio calculations, have been observed. We conclude from our measurements that the atomic arrangement in these…
The electronic structures of clean InAs(100) surfaces have been investigated by in situ high-resolution electron-energy-loss spectroscopy. Intrinsic electron accumulation layers with carrier densities strongly depending on the surface reconstruction are formed on both As-stabilized and In-stabilized surfaces. The corr…
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Absorption spectra of GaAs/GaAlAs Fibonacci superlattices (FSL) with magnetic fields parallel to the layers show self-similarity at field values scaled by ${\mathrm{\ensuremath{\tau}}}^{2}$ [\ensuremath{\tau}=(1+ \ensuremath{\surd}5 )/2]. The one-dimensional nonperiodicity of the FSL affects the carrier motion perpend…
${\mathrm{Ga}}_{0.5}$${\mathrm{In}}_{0.5}$P alloys order spontaneously during growth into a (111) monolayer superlattice despite the fact that this is not the lowest-energy structure of the three-dimensional bulk compound. Using first-principles total-energy calculations, we show that a novel electronically driven sur…
An electro-optic (EO) polymer-based integrated optic Mach–Zehnder modulator with a measured frequency response up to 20 GHz is reported. The device was fabricated with an EO polymer supplied by Akzo Research, bv, and utilized 50 Ω microstrip drive electrodes. A half-wave voltage of Vπ=9 V and a modulation depth of 90%…
We have studied the adsorption of cyclohexane and water on molecularly smooth mica using an angle-averaging, refractive-index-matching ellipsometric technique. The isotherms are linear for submonolayer coverages, showing the importance of entropy effects, and give finite thicknesses (\ensuremath{\approxeq}2 nm) at sat…
Abstract Bitumen from thermal recovery processes is produced mainly in the form of water-in-oil emulsions. Generally, it has been believed that these emulsions form al restrictions in and around the wellbore, and/or in the surface sampling ports, but not in the reservoir. Thus, it has been assumed to be appropriate to…
A laser method based upon carbon ion implantation and pulsed laser melting of copper has been used to produce continuous diamond thin film. Carbon ions were implanted with ion energies in the range of 60 to 120 keV, and doses of 1.0 x 10(18) to 2.0 x 10(18) ions cm(-2). The ion-implanted specimens were treated with na…
Leucine-160 of chloramphenicol acetyltransferase (CAT) has been replaced by site-directed mutagenesis to investigate enzyme-ligand interactions at the 1-hydroxyl substituent of the substrate chloramphenicol. The consequences of the substitution of Leu-160 by glutamine and by phenylalanine were deduced from the steady-…
Successive tensile deformations at different temperatures of high-purity α-iron monocrystals, combined with stress-relaxation tests, reveal that in stress/temperature regime III, i.e. below ≈︁ 120 K, an Arrhenius equation with practically constant pre-exponential factor is valid for the temperature and strain-rate dep…
The microstructures of Nd-Fe-B magnet were examined by scanning electron microscopy (SEM) with wavelength dispersive x-ray spectrometer (WDS) specially equipped lead stearate crystal for lighter elements detection. Investigations were performed on the samples of (Nd0.9Dy0.1)15FebalB8 magnets with various oxygen and ca…
Two microscopic models have been proposed to explain the large intrinsic linewidth of barium ferrite. The first is a two-magnon scattering process due to an intrinsic disorder associated with the unique trigonal bipyramidal site in the crystal. [E. Tsantes and L. M. Silber, J. Appl. Phys. 63, 3350 (1988)]. The second…
Two methods were used to prepare NdFeB alloy particles for sintered magnets: the reduction-diffusion (R/D) method and the melting and casting (M/C) method. In both materials, the Nd-rich phase appears along grain boundaries, but the grain size of the R/D alloy is much smaller than that of the M/C alloy. The shape of t…
Wigner condensation is found to have lowest energy on the perovskite lattice structure. It is suggested that this may be of relevance for studies of high-temperature superconductivity.
Crystal structure parameter of Cr1−xMxAs (M=Ti, Fe, Co, and Ni; x≤0.1) have been precisely determined as a function of temperature from 77 to 320 K. Discontinuous changes of lattice parameters have been observed at a special temperature. By this temperature the Néel temperatures TN of Cr1−xMxAs have been determined be…
Extended x-ray-absorption fine-structure spectroscopy (EXAFS) has been used to determine the position of Zr within the unit cell of Sm2Co17. Induction-melted Sm2Co17:Zr ternary alloys, aged at 1180 °C, then quenched, consisted of intimately mixed H2:17 and R2:17 having Zr in solid solution as well some regions of R2:1…
Dynamic vector Preisach models of hysteresis are developed, and the identification problem for these models is posed. It is shown that some experimentally measured relaxation times can be used for the solution of the identification problem for the dynamic vector Preisach models. Moreover, it is shown that the identifi…