Materials Literature
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Abstract A number of leaks were discovered at refinery piping welds in lean amine service at temperatures which, in the past, had been considered to be below the threshold temperature for stress-corrosion cracking. Therefore, these welds had not received post weld heat treatment. Subsequent metallurgical examination r…
Ions dissolved in nematics screen the flexoelectric polarization induced by distortions. I show that for long-range distortions (long compared to the Debye length), the free energy associated with these effects varies as the fourth power of the distortion wave vector. This free energy has a magnitude at least ${10}^{5…
We consider densely packed assemblies of icosahedra, such that icosahedral bond-orientational order is enforced throughout the sample. The peaks in the calculated diffraction patterns may be put in a one-to-one correspondence with the electron and x-ray diffraction patterns from icosahedral Al-Mn alloys, allowing the…
Transmission electron microscopy study of hot-pressed and hot-deformed Nd0.14(Fe0.94B0.06)0.86 magnets shows that the magnetic alignment is achieved by the formation of a microstructure consisting of platelets of Nd2Fe14B grains with the c axis normal to the platelet surface and parallel to the press direction. Magnet…
A complete systematic IR study (400 to 4000 cm−1) of AgNO3 is carried out over a wide range of temperature (30 to 195 °C) and new results are reported for the order–disorder phase transition II–I. The study includes measurements and interpretations of the IR spectral band shape, intensities, and frequencies of the int…
The surface potential of insulating sheets – and Teflon FEP in particular – charged by a negative corona decays faster than the potential of samples charged to the same level in vacuo by an electron beam. This motivated the reinvestigation of the charge decay in air. The samples are corona charged on a grounded metal…
CuGaO2, with the delafossite structure, is a low mobility p-type semiconductor when doped with calcium. From photoeloctrochemical measurements the interband optical transitions are determined at 1.19 (indirect), 2.72 (direct), and 3.4 eV (indirect). The valence band edge is 5.1 cV below the vacuum level, typical for t…
The heat capacities of ternary TlInS2 and TlInSe2 layer crystals are studied a t low temperatures. The dependence of the characteristic temperatures θD on the temperature of these crystals is plotted. It is shown that the low-temperature part of the heat capacities of TlInS2 and TlInSe2 depends on the temperature acco…
A theory based on Fourier-Bessel expansions and the T-matrix method is presented to compute the reflection and transmission characteristics of dielectric or perfectly conducting cylindrical gratings embedded in a dielectric slab. It is shown that such gratings discriminate quite effectively between TE and TM polarizat…
Magnetic crystalline anisotropy of Pd 1- x Fe x (\(0.1{\lesssim}x{\lesssim}0.3\)) in cubic phase was studied by torque method. An abrupt change was found in the composition dependence of anisotropy constant K 1 at 4.2 K around x =0.17: from +17×10 4 erg/cm 3 for x =0.16 to -6×10 4 erg/cm 3 for x =0.18. Values of K 1 f…
Current oscillations or ``narrow-band noise'' peaks associated with nonlinear charge-density wave conduction in ${\mathrm{NbSe}}_{3}$ are studied in the presence of a thermal gradient. Multiple splitting of the spectral noise peaks are observed for both Peierls transitions, suggesting the formation of velocity-coheren…
The isotropic Raman spectra of the ν1 (A′1) mode of NO−3 ions are measured in molten LiNO3–RbNO3 mixtures at various concentrations and at temperatures from 478 to 750 K. The isotropic Raman bandwidth Γiso is found to increase almost linearly with the mole fraction c(Li+) of LiNO3, from 9–13 cm−1 for molten RbNO3 to 2…
Three different spherical-shaped models of the amorphous alloy ${\mathrm{Ge}}_{0.20}$${\mathrm{As}}_{0.40}$${\mathrm{Se}}_{0.40}$ , obtained from quenching of the molten mixture of the elements, were constructed. The models were built by computer simulation of an x-ray diffraction experiment. Initial models were creat…
Interface excitons caused by stacking faults in BiI 3 , crystals have been investigated on absorption, photoluminescence and its excitation spectra. Characteristic three sharp absorption lines (called R , S and T ), appear close to the fundamental absorption edge. The temperature dependence of the line shape shows a t…
Numerical calculations of the conductances of specific two-dimensional networks of conductors whose values are described by a variety of distributions have been carried out. The results are found to differ only slightly from a well-known estimate which predicts that the conductance G of such a network to be given by t…
We have studied the glass transition in vitreous silica using the technique of high-temperature light scattering. We report the temperature dependence of the Landau-Placzek ratio of Homosil up to and through the glass transition. The results show that the compressibility \ensuremath{\beta} of silica increases sharply…
Angle-resolved ultraviolet photoemission spectroscopy measurements have been made from the (0001) and (112\ifmmode\bar\else\textasciimacron\fi{}0) surfaces of magnesium in the photon energy range of 15 to 115 eV. Both bulk and surface features are identified. The occupied bands along the [0001] direction are character…
An analytical solution is given for the contrast from an individual pointlike defect in the cathodoluminescence mode of a scanning electron microscope. This solution takes into account the influence of recombination at the surface and the internal optical absorption. The cathodoluminescence contrast is shown to differ…
Computations have been carried out to determine how the magnitude and shape of the polymer and salt induced (psi)-type CD spectra depend on the structural properties of a collection of randomly oriented large chiral aggregates. Uniaxial polarizable groups located at the cubic lattice points have been used to model the…
Raman scattering measurements are used to investigate the lattice-dynamic properties of ${\mathrm{Cd}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Zn}}_{\mathrm{x}}$Te. The samples were thin films grown by molecular-beam epitaxy on GaAs substrates. The first-order Raman spectra for the ternary samples show two sets…