Materials Literature
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The search of the off-centre displacement of an impourity iron from the crystal lattice site in the ground electronic state has been performed by the ionic thermocurrent (ITC) method for Ga+, Ge2+ v− c, and Sn2+ v− c centres in some alkali halides. No ITC peak has been found at T>5 K for Ga+ ions. One ITC peak at the…
Cracking, or disbonding, along the fusion boundary in dissimilar metal welds has been a persistent problem, particularly in applications where austenitic alloys are clad on to structural steels for corrosion protection. Many failures in dissimilar metal welds occur as a result of cracking along a boundary that runs pa…
Different plant analysis methods including varied incubation times with 0.5N and IN hydrochloric acid (HCl), diacid [nitric (HNO3) and perchloric (HClO4) acids], triacid [HNO3, sulfuric acid (H2SO4) and HClO4], H2SO4+hydrogen peroxide (H2O2) (Wolf method), and 0.5N and lN ammonium acetate (NH4OAc) were evaluated for m…
A chain-adapted symmetry-mode analysis is presented for the symmetry change R 3 m > C12/c1 in ferroelastic lead phosphate. The primary and the secondary modes are derived for all relevant Wyckoff positions. The splitting schemes of the orbits and the patterns of the displacive modes are compatible with experimental di…
Nanocrystalline La 0.5 Na 0.5 TiO 3 powders were prepared by the stearic acid-gel method, and the grain sizes could be controlled by varying annealing temperatures. The sizes were determined to be from 14 to 50 nm using Scherrer's formula. A very strong blue-light emission band around 480 nm was clearly observed in th…
Instead of studying the cholesteric-smectic A transition from the analogy with superconductors, we present a direct investigation of the properties of this transition. The transition is of first order and a very simple relationship between the four basic lengths (correlation length, penetration length, layer spacing o…
A carbon tetrafluoride plasma discharge using a grafting mechanism and very short treatment times (a few milliseconds to a few seconds) was used to obtain high-quality reproducible surfaces that permit the homeotropic alignment of lyotropic as well as thermotropic liquid crystals. The intermolecular interactions betwe…
Two mechanisms of optical response in liquid crystals (LC) of homologous series 4-n-butyl-4′-n-alkoxyazobenzenes (BAAB), namely the photochemical phase transition and reorientation in bulk of LC are considered. The temporal parameters of writing (Ar+ laser) and erasing (He-Ne laser) of information on BAAB on the basis…
Abstract The thermal decomposition equilibria of ammonium europium chlorides (NH 4 ) 3 EuCl 6 , (NH 4 ) 2 EuCl 5 and NH 4 Eu 2 Cl 7 have been investigated by total pressure measurements in a membrane zero manometer. The thermodynamic data of these solid phases have been derived from the decomposition functions. The st…
In einer umfassenden Untersuchung werden die besonders günstigen Korrosionsschutzeigenschaften Galfan-schmelztauchveredelter Feinbleche sowohl im unlackierten als auch im bandbeschichteten Zustand aufgezeigt. An fünf unterschiedlichen Bewitterungsorten wurden feuerverzinkte und Galfan-schmelztauchveredelte Prüfbleche…
A derivation of the equation for the hopping current of electrons and holes (electron vacancies) among impurities of a single species in three charge states [(−1), (0), and (+1)] is given in the continuum approximation. The screening length of an electrostatic field and the diffusion length of charge carriers are calc…
Abstract An oscillating cup viscometer interfaced to an automatic data acquisition and processing system (computer, interface, software) was built for viscosity measurements in molten salts below 1400 K. In order to avoid the “meniscus effect”, the main source of errors of the method, the measurements were carried out…
A model of electrically active and neutral native point defects in SnO2 is developed. Thermodynamic analysis of the equilibrium of the native point defects makes it possible to construct the phase diagram $$P_{O_2 } - T - x$$ of lead dioxide. The contradiction between n-type monopolar conductivity and the two-sided ho…
There is a continuing desire to obtain sacrificial plated coatings that provide ever higher standards of protection. This paper looks at alternatives to cadmium dye to its toxic and carcinogenic characteristics. Alloy combinations with zinc are considered. It concludes that tin‐zinc alloy plating gives excellent corro…
Transient currents were measured by the time-of-flight technique in films of aromatic polyimides based on 9,10-bis(p-aminophenyl)anthracene and a series of diimide fragments. The electric field and temperature dependences of the hole and electron drift mobilities were detected. In amorphous films of the soluble polyim…
Palygorskite was identified in lower Eocene clays and porcellanites in Holes 959D, 960A, 960C, and 961A; in upper Albian to Cenomanian clays with chert in Hole 962B; and in undated clays in Holes 962B and 962C of Ocean Drilling Program Leg 159. Palygorskite is particularly abundant in lower Eocene bluish claystones of…
Changes in elastic anisotropy and fracture toughness anisotropy of a lead zirconate titanate (PZT) piezoelectric material as a function of depoling temperature were investigated using ultrasound and Vickers indentation. A gradual transition from anisotropic to isotropic properties occurs with increased depoling temper…
Anelastic behaviour was studied in hydrogenated Inconel 600 alloy. Two complex peaks were detected in the temperature range 80–500 K. The low-temperature peak (100–270 K) was recognized as a hydrogen-induced Snoek-like relaxation peak, while the high-temperature peak may be caused by some transient processes. The low-…
For complex thio- and selenophosphides the character of phase transitions and the vibration spectra of the crystal lattices are compared. The splitting of internal vibrations of (P2X6)4- anions reflects the anisotropy of crystal fields. The substitution of the chalcogen atoms in anion sublattice or the metal atoms in…
The reflection-transmission phenomena in sculptured thin films (STFs) of the ‘‘zigzag’’ type are considered. A finite layer of an STF is modeled as a stack of Motohiro-Taga interfaces. The boundary value problem for a plane wave obliquely incident on a single Motohiro-Taga interface is solved. This solution, incorpora…