Materials Literature
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The low-energy part (<20 meV) of the ground-state magnetic excitation spectra of Ho 2 Co 17 and Ho 2 Fe 17 were found to consist of three modes: (i) a highly dispersive transition-metal mode; (ii) a non-dispersive local mode and (iii) a weakly dispersive mode degenerate with the local mode at the zone boundary. These…
By using an elastic body approximation, lattice vibrations of a small particle are discussed. Consideration of both vector fields and a scalar field yields the proper vibrational modes. Eigenfrequencies of the elastic vibrations are derived by considering circumstances surrounding a small particle: matrix effect, surf…
A comprehensive reference on micelles and vesicles as membrane models. Describes the properties of different membrane mimetic agents and emphasizes such applications as those in enzymology, reactivity control, and solar energy. Includes thorough data tabulations and references to original research publications.
This paper reports an x-ray diffraction study of structures and restacking transitions within the $B$ phases of heptyloxybenzylidene-heptylaniline. The system evolves from a hexagonal close-packed structure, through intermediate orthorhombic and monoclinic phases, to a simple hexagonal structure. The monoclinic phase…
Standing waves of x rays have been used to determine the positions of bromine atoms in submonolayer coverages on a (111) silicon surface. In addition to the bromine position normal to the crystal surface its components relative to a plane inclined to the surface are also measured. This information suffices to establis…
The authors report X-ray photoemission measurements of core level shifts in TaS 2 , Fe 1 3/TaS 2 , Mn 1 4/TaS 2 and Ni 1 3/TaS 2 . The shifts are related to charge transfer from the intercalate 3d ions to the host band structure, and have implications concerning observations of charge density wave amplitudes.
Optical absorption and ESR spectra of reduced vanadium centres in Ca 2 NaMg 2 V 3 O 12 are reported. The spectra are interpreted as arising from tetrahedrally coordinated V 4+ and octahedrally coordinated V 3+ . The ESR and optical data are correlated using molecular orbital (MO) theory. The composition of the flux-gr…
Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are…
New information on the magnetic ordering of the iron ions in bismuth ferrite BiFeO 3 was obtained by a study with a high-resolution time-of-flight neutron diffractometer. The observed splitting of magnetic diffraction maxima could be interpreted in terms of a magnetic cycloidal spiral with a long period of 620+or-20 A…
It is pointed out that in fluorescent and Raman scattering by molecules in or near a small particle, large enhancements in the scattered signals are obtained when both the incident and the fluorescent frequencies coincide with eigenfrequencies of the particle. Numerical results are presented for spherical particles wi…
Bend-contour patterns are used to investigate the structure features of crystals of hexagonal selenium and tellurium grown in thin amorphous condensates of Se, SeTe, CuTe. The results are compared with microinterferometry data. Two bend effects are revealed: a hitherto unknown continuous bending, progressing with cr…
Photoemission involving an intermediate core-hole \ensuremath{\rightarrow} bound-valence transition shows a strong resonance enhancement as the photon energy is tuned through the intermediate-state transition energy. We have studied the effects of electronic relaxation in both intermediate and final states on the line…
The changes of the vibrational amplitudes of molecules in a crystal lattice, due to interaction between the optically induced dipoles, are shown to account for the nonlinear refractive index of a crystal. The general expressions for the fourth- and sixth-rank tensors, ${\ensuremath{\chi}}_{\mathrm{ijkl}}(\ensuremath{-…
Elastic scattering cross sections of electrons by O 2 were measured by a cross-beam method at incident energies between 200 and 500 eV and at scattering angles, θ, from 4° to 150°. The relative cross sections at 500 eV were normalized to the absolute ones measured by Bromberg at 2–40°. The absolute values at 200–400 e…
The fluorescence, Raman, and fluorescence excitation spectra of diphenyloctatetraene and diphenylhexatriene condensed on rough silver are reported. The fluorescence excitation spectra reveal that on silver the normally dipole-forbidden 1Ag←X 1Ag absorption takes place in addition to the allowed 1Bu←X 1Ag process. This…
Angle-resolved and angle-integrated ultraviolet-photoemission-spectroscopy (UPS) investigations have been carried out over the entire concentration range $0<x<1$ of the sodium-tungsten-bronze system ${\mathrm{Na}}_{x}\mathrm{W}{\mathrm{O}}_{3}$. The results indicate that the rigid-band model used by several auth…
We present a simple model of staging in graphite intercalation compounds. Unlike previous theoretical studies, finite-$T$ calculations based on our model yield the staged structures which are observed experimentally. Certain choices of model parameters result in more complex structures such as those predicted recently…
Mg(0001) has been studied with angle-resolved photoemission spectroscopy for photon energies in the range 7.0-26.8 eV. The polar-angle dependence of the photoelectron emission was recorded along the two symmetry lines $\overline{\ensuremath{\Gamma}}\overline{M}$ and $\overline{\ensuremath{\Gamma}}\overline{K}$ of the…
To cancel the average bulk macroscopic field compensating charge should be induced on the polar surface of compound crystals. In this paper we clarify the mechanism of the charge compensation by performing the DV-X α calculations on the clusters M 13 X 13 representing the polar surface of the rock-salt type crystals.…
High field magnetization and transverse magnetoresistance of itinerant electron helical magnet MnSi are investigated at temperatures between 4.2 K and 77 K in pulsed field H 0 up to 500 kOe. Large high field susceptibility and negative magnetoresistance are obtained reflecting a large spin fluctuation in this compound…