Materials Literature
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We give two general integral expressions for the first and second derivatives of the so-called stick probability functions which are commonly used in analyzing x-ray-scattering results. Then it is shown that by letting the length of the stick go to zero, the limit of the second derivative can be expressed in terms of…
We have determined the Raman scattering cross section of pyridine molecules adsorbed on a "smooth" surface of silver prepared and characterized in an ultrahigh-vacuum chamber. The Raman intensity of the 1004-${\mathrm{cm}}^{\ensuremath{-}1}$ line of adsorbed pyridine was calibrated against the scattering intensity of…
A surface dielectric function of a semi-infinite plane-bounded metal is defined in the spirit of the plasmon-pole dielectric function of the bulk. It is modeled in such a way that the surface-plasmon dispersion relation is recovered for small momentum transfer. This function is employed to compute the image potential…
Infrared-reflectivity results on ${\mathrm{Cu}}_{3}$V${\mathrm{S}}_{4}$ and Raman scattering data as a function of temperature and hydrostatic pressure for ${\mathrm{Cu}}_{3}M{\mathrm{S}}_{4}$ (with $M=\mathrm{V},\phantom{\rule{0ex}{0ex}}\mathrm{N}\mathrm{b},\phantom{\rule{0ex}{0ex}}\mathrm{T}\mathrm{a}$) are reported…
A metal-insulator transition was found by Aubry in a one-dimensional tight-binding model containing a modulation potential incommensurate with the crystal lattice. In this article the extended bandlike states that occur in the metallic regime are studied using a quasiclassical approach. Near the metal-insulator transi…
Raman scattering and x-ray diffraction measurements are used to correlate finite-size effects on the Raman spectra of nonpolar vibrational modes in BN. The BN microcrystalline samples used exhibited domain sizes varying from 4.4 to 78.5 nm in the plane and 1.5 and 47.5 nm perpendicular to the planes. The Raman measure…
An unstretched alpha -form specimen of polarised PVDF shows four TSC peaks designated P 1 , P 2 , P 3 and P 4 in ascending order of temperature. The P 1 and P 2 peaks are associated with the dipolar depolarisation due to the alpha a and alpha e relaxations, respectively. The P 3 and P 4 peaks may both be attributed to…
Abstract Transition metal complexes often have low‐lying excited electronic states and, as a consequence, tend to be electronically labile, i.e. , their electronic properties exhibit pronounced sensitivity to external perturbations. Often drastic changes in various spectroscopic properties indicating substantial elect…
The high resolution infrared luminescence spectra of ReCl6 2- in K2PtCl6 and of ReBr6 2- in Cs2ZrBr6 have been measured between 10 000 cm-1 and 3000 cm-1 at liquid helium temperatures. Comparison with the luminescence spectra in the visible region has enabled nine luminescence transitions to be observed in the bromide…
Non-empirical calculations of the electronic structure of NiO and related compounds have proven to be problematic, in that NiO is an insulator both above and below the antiferromagnetic ordering temperature (TN approximately 525K) with a gap of approximately 4 eV. This is so despite the partly filled d-band on the Ni…
The (220) lattice plane spacing of an almost perfect crystal of silicon was measured by means of a combined scanning ($\mathrm{LLL}$) x-ray interferometer and a two-beam optical interferometer. From 170 measurements, a value ${d}_{220}=(192015.560\ifmmode\pm\else\textpm\fi{}0.012)$ fm results in vacuum at 22.50\ifmmod…
A differential anomalous x-ray scattering technique has been developed for structural studies of disordered and amorphous systems. The results on amorphous Ge${\mathrm{Se}}_{2}$ are consistent with the twofold coordination of Se and the fourfold coordination of Ge. The results on amorphous GeSe are consistent with thr…
Abstract The microstructure of melt-crystallized linear polyethylene has been correlated with the variables of crystallization for most readily attainable conditions. All samples are filled with well defined lamellae with an average chain inclination of about 35° to lamellar normals. The lamellar thickness depends up…
Abstract The lamellar microstructure of a wide range of melt-crystallized polyethylenes has been examined in the context of spherulitic organization. Radial continuity is achieved through lamellar continuity. In the simplest cases ridged or planar sheets grow outwards along b, maintaining their identities over distan…
Abstract The morphology of melt-crystallized polyethylene has been surveyed, and it has been revealed that all specimens are highly lamellar. Classification of the textures is possible in terms of the lamellar profiles in b-projection, i. e. down the radii of spherulites. For polyethylene crystallized as the orthorh…
Abstract Die Phasenbeziehungen in den Titelsystemen werden unter besonderer Berücksichtigung der Sn‐ Spinellbildung untersucht.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTWear of anodized aluminum-polymer lithographic printing platesJohn W. Noble III and Henry Leidheiser Jr.Cite this: Ind. Eng. Chem. Prod. Res. Dev. 1981, 20, 2, 344–350Publication Date (Print):June 1, 1981Publication History Published online1 May 2002Published inissue 1 June…
The Mössbauer spectroscopy is applied to the perovskite compound RbFeF 3 . It is concluded that in the phase realized below T 1 (39 K) the spontaneous magnetization originates in a canting of the spins, i.e. the spins are almost along a pseudo-cubic [011] axis but cant by about 6° from the [011] axis, yielding spontan…
Abstract It is shown that the chemical shift of the generally utilized internal reference for 1 H NMR measurements in superacid media, namely, tetramethylammonium bromide, which is normally fixed at 3.10 ppm from external TMS, changes with the composition of the acid mixture (HF or HSO 3 F:SbF 5 ). This is attributed…
Abstract The visible luminescence spectrum of solid neon containing small amounts of N 2 or O 2 is investigated at 7.8 K using low‐energy electrons. Double‐doping experiments employing N 2 and × (where × is either O 2 , CO or Ar) are also carried out. Particular attention is given to the interpretation of the α(N 2 D—…