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Coupled nature of magnetic and structural transition in MnNiGe under pressure
Differential-thermal-analysis investigation in MnNiGe under pressure (8 kbar) shows that (i) the first-order TiNiSi-to-${\mathrm{Ni}}_{2}$In-type structural transition point ${T}_{D}$ decreases with increasing hydrostatic pressure ($\frac{d{T}_{D}^{h}}{\mathrm{dP}}=\ensuremath{-}12.2$ and $\frac{d{T}_{D}^{c}}{\mathrm{…
Effects of Charge Injection and Extraction on Tree Initiation in Polyethylene
Initiation of electrical treeing in polyethylene is discussed with the emphasis of a charge injection and extraction process, which is considered to feature the incubation period during which there are no apparently visual change and no detectable partial discharges. Some evidences for the process are shown by electri…
A simple method of estimating the minor loop hysteresis loss in thin laminations
A simple and practical method of correcting the hysteresis loss in a thin lamination for the effects of minor loops is described. The necessary correction is applied to the losses that would occur under conditions of sinusoidal flux density and the required empirical factor is derived using a broad range of loss measu…
Ionic conductivity of quenched alkali niobate and tantalate glasses
Alkali niobate and tantalate glasses have been prepared by rapid quenching. These glasses exhibit room-temperature ionic conductivities as high as 10−5 (Ω cm)−1 and electronic conductivities less than 10−11(Ω cm)−1. In the case of LiNbO3, the glass conductivity is many orders of magnitude greater than that of the sing…
A Generalized Formulation of Dual Radiation Action
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…
On the Structure of Bismuthsesquioxide: The α, β, γ, and δ‐phase
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…
The band structure of the tetracyanoplatinate chain
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…
Theory of wave propagation in periodic structures
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…
Crystallinity of Polymers and the Means to Influence the Crystallization Process
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…
Retarded electromagnetic modes in a ferromagnetic slab
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…
The decay time of N3 luminescence in natural diamond
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…
The origin of the Triassic clay assemblages of Europe with special reference to the Keuper Marl and Rhaetic of parts of England
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…
Enhanced coloration of MgF2crystals byFe2+ions acting as hole traps
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 (…
Theory of angle-resolved photoemission from the bulk bands of solids. I. Formalism
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…
Electron attachment to van der Waals polymers of water
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…
Luminescence studies of plasma-deposited hydrogenated silicon
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…
Photoemission from surface states and surface resonances on the (100), (110), and (111) crystal faces of aluminum
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…
Vacancy-interstitial pair production via electron-hole recombination in halide crystals
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…
Photoemission study of the bulk and surface electronic structure of single crystals of gold
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…