Materials Literature
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Dual radiation action is a process in which cellular lesions are produced as a result of the interaction of pairs of sublesions that are molecular alterations produced by ionizing radiation.Previous formulations of this process have employed a number of simplifying assumptions that limit the accuracy and the range of…
Abstract The structures of four polymorphs of Bi 2 O 3 were investigated by means of X‐ray and neutron powder diffraction. The position parameters of the oxygen atoms in α‐Bi 2 O 3 were refined. High temperature neutron diffraction shows that a complicated disorder exists in the oxygen sublattice of the fluorite relat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe band structure of the tetracyanoplatinate chainMyung-Hwan Whangbo and Roald HoffmannCite this: J. Am. Chem. Soc. 1978, 100, 19, 6093–6098Publication Date (Print):September 1, 1978Publication History Published online1 May 2002Published inissue 1 September 1978https://pubs…
A study is made of the propagation of electromagnetic waves in a one-dimensional medium with a periodic variation of the refractive index. An asymptotic method is used to reduce the problem to the solution of well-known equations for coupled waves in which the expression for the coupling coefficient differs from the t…
One of the most important factors determining the properties of a solid polymer is the packing order. Crystallization is a means to control the degree and morphology of packing. There is a great difference between "free” and “induced” crystallization.The “free” crystallization leads to quasi-isotropic products, which…
The authors find the dispersion relation of the coupled magnetic-electromagnetic modes in a ferromagnetic slab in the Voigt geometry (applied static field H 0 and magnetisation M 0 in the plane of the slab, propagation in the perpendicular direction in the plane). The results differ significantly from those found by H…
Abstract Measurements are reported of the decay time of photoluminescence from the N3 centre: an impurity centre commonly found in natural diamond. The intrinsic decay time at low temperature is found to be 41 ± 1 ns. The decay time is specimen dependent, decreasing with increasing concentrations of pairs of substitut…
Abstract Hypotheses are reviewed on the origin of the magnesium-rich Triassic clays which characterize the Germanic facies of western Europe and north Africa. Relations between clay minerals, megafacies and stratigraphy are described from 28 localities in the Triassic Keuper Marl, Tea Green Marl and Rhaetic sediments…
A study is made of the growth of the $F$ band in Mg${\mathrm{F}}_{2}$ crystals irradiated with $^{60}\mathrm{Co}$ $\ensuremath{\gamma}$ rays as a function of irradiation time at room temperature. It is shown that a rapid initial-growth stage in the form of a saturating exponential occurs for crystals containing iron (…
A theory for describing the angle-resolved photoemission spectra from the bulk bands of solids is developed which views the photoemission process as a single-step coherent emission of electrons from atomic sources into a final state of well-defined momentum. The final state is assumed to be free-electron-like except i…
Negative ions resulting from electron attachment to van der Waals polymers of water are reported. The most prominent ions observed consititute a homologous series with the stoichiometric formula OH−(H2O)m. They and the positive ions H+(H2O)m are ascribed to ion–molecule half-reactions. The ionization of van der Waals…
The photoluminescence of plasma-deposited amorphous silicon is investigated. The luminescence intensity and spectral line shape are shown to be sensitive to many deposition variables, in particular the power coupled into the discharge, the concentration of silane in the gas stream, and the deposition substrate tempera…
The angular-resolved energy distributions for photoelectrons emitted from the (100), (110), and (111) crystal faces of aluminum are presented for photon energies in the range 7.0-11.6 eV. The emission in this photon energy range is dominated by surface photoemission excited by the normal optical field or the surface-p…
The nature of the electronic states through which band-to-band excitations or excitons evolve into $F\ensuremath{-}H$ pairs is central to an understanding of defect production in halide crystals. The present paper develops a recent empirical model in which a self-trapped exciton becomes an $F\ensuremath{-}H$ pair thro…
Angle-resolved energy distributions for photoelectrons emitted from the (111), (110), and (100) crystal faces of Au are presented for photon energies in the range 7.0-11.6 eV. The variation of peak-energy positions as a function of photon energy and electron emission angle has been studied. We have found very good qua…
The diffusion of a labeled particle on a one-dimensional chain is discussed. It is shown that the long-time behavior is dominated by density fluctuations leading to a ${t}^{\frac{1}{2}}$ dependence of the mean-square deviation in agreement with Monte Carlo results of Richards.
We report optical absorption measurements made on thick, highly pure crystals of ${\mathrm{Cu}}_{2}$O at 1.6 K. For the first time direct evidence is provided for a phonon-assisted paraexciton absorption edge. The relative strengths of phonon-assisted paraexciton and orthoexciton absorption edges are discussed.
The ferroelectric and dielectric properties of La, Sr, Zr, Fe and Mn doped BaTiO 3 ceramic are measured within wide limits of the amplitude E approximately of the external electrical AC field. At sufficiently low E approximately the losses are not ferroelectric in origin but are rather determined by the low frequency…
This book describes two-, three-, and four-dimensional crystallographic groups, primarily by the use of tables. Complete groups of four-dimensional tables are presented for the first time. The description of the four-dimensional crystallographic groups provides a clearer insight into dimension-independent crystallogra…
During the past 15 years, surfaces have been increasingly studied on the atomic scale. As a result, their atomic structure and composition and the dynamics of gas-surface interactions are much better understood. Modern surface science is beginning to have an impact on many technologies. Techniques are readily availabl…