Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The relationship between the problem of the symmetry of a plane tiling and the properties of nonintegrable dynamic systems is reviewed. The formation of stochastic layers and a stochastic web in the motion of linear and nonlinear oscillators subjected to a perturbation is discussed in detail. Emphasis is placed on res…
PbTiO3 thin films have been grown successfully for the first time by using purely metalorganic precursors, namely, titanium isopropoxide and tetraethyllead. A scanning electron micrograph showed dense and noncolumnar growth with good surface morphology. Temperature-dependent x-ray diffraction studies provide evidences…
In order to understand some discrepancies in the recent Letter of Griniasty and Fishman, a study has been made of localization by a one-dimensional potential with slowly varying period. Away from the band center, localization is produced by local regions in which the Bragg condition allows backward scattering, and the…
Se presenta un estudio de la resistencia mecánica del yeso, basado en su refuerzo mediante la adición de polímeros sintéticos, en forma de fibras y dispersiones acuosas. Se pretende mejorar las características mecánicas del yeso, entre cuyas cualidades se pueden enumerar las siguientes: abundancia en España, bajo cost…
Electronic band structures of manganese compounds having cubic perovskite-type structure are calculated by a self-consistent augmented-plane-wave method. The energy dispersion, density of states and Fermi surface calculated for the nonmagnetic state of Mn 3 MC (M=Zn,Ga,In,Sn) are shown. The ferromagnetic band is also…
Introduction ‘Water is the most ubiquitous plasticizer in our world.’ It has become well established that plasticization by water affects the glass-to-rubber transition temperatures ( T g ) of many synthetic and natural amorphous polymers (particularly at low moisture contents), and that T g depression can be advantag…
We report on Raman scattering by longitudinal optical phonons in In1−y−zAlyGazAs (1−y−z=0.53) lattice matched to InP. The quaternary alloys were grown on (001) InP by molecular beam epitaxy. The phonon spectra exhibit three-mode behavior. The frequencies of AlAs- and GaAs-like modes vary linearly with the concentratio…
A stretch deformation method has been developed for quantitative study of adhesion and deformation of metal/polymer structures. The adhesion energy is directly measured from the difference in the load versus elongation curves between film/substrate and substrate structures. This method has been applied to study struct…
We have measured mole fractions of two of the major stable species at the surface of a silicon substrate during filament-assisted diamond growth as a function of the filament-to-substrate distance. Input gases were methane and hydrogen. A quartz probe withdrew gases at the growing surface, and the gases were sampled w…
TbPO 4 shows two successive magnetic phase transitions, the lower of which is connected with a Jahn-Teller induced reduction of crystal symmetry. In both phases, the magneto-electric (ME) effect (which is larger that in other known ionic crystals) was measured to determine the temperature and magnetic-field dependence…
Orientational distributions of the rod-shaped tobacco-mosaic-virus particle in magnetically aligned nematic solutions ($0.05M$ borate buffer, $p\mathrm{H} 8.5$) were measured by analysis of the angular spread of x-ray diffraction patterns. We measured Gaussian orientational distributions with order parameters varying…
It is found from TEM observations in NaNbO3 crystals that the phase transition series from the P phase is P—R1—R2—S and that one, related to the Q phase is Q—Q1—Q2—S. It is shown that the R phase is composed of two subphases R1 and R2. The main difference between R1 and R2 is that the η values corresponding to these t…
The absorption spectra of MoO3 amorphous thin films in the thickness range from 50 to 350 nm are studied as a function of thickness in the temperature range from 20 to 275°C. The validity of the Urbach rule is investigated and the related parameters are estimated. It is confirmed that absorption in these layers is due…
The structure and optical properties of polycrystalline MoO3 thin films prepared by annealing of black molybdenum layers produced by chemical vapor deposition on fused quartz substrates are determined. Three different modes of annealing are used. X-ray diffraction spectra reveal that all the films consist of MoO3 crys…
C 8 H 4 S 8 + .I 3 − cristallise dans P1 avec affinement jusqu'a 0,036. Les radicaux cationiques s'assemblent en dimeres, les molecules etant distantes de 3,41 A
We propose a method for determination of the complex refractive index of absorbing materials either in bulk or film geometry by measuring its reflectivity when coated with a well-characterized transparent dielectric at two specific optical thicknesses: n(1)d(1) = lambda(0)/4 and n(1)d(1) = lambda(0)/2. The complex ref…
We report a self-consistent calculation of the optical nonlinear response of the electrons of a small metal spherical particle. We use the jellium model to describe the metal sphere and work within the random-phase approximation. This calculation allows us to obtain general expressions of the linear polarizability and…
We present an x-ray diffraction study of the charge-density wave (CDW) in a blue-bronze single crystal doped with vanadium atoms. We show that the 2${k}_{f}$ (${k}_{f}$ is the Fermi wave vector) component of the distortion wave vector, which is about 0.75 at low temperatures in the standard blue bronze ${\mathrm{K}}_{…
Calculations of the atomic and electronic structure of ${\mathrm{Ca}}_{\mathrm{x}}$${\mathrm{Al}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$ glasses (with x=0.70, 0.60, 0.50, and 0.33) and of the crystalline intermetallic compound ${\mathrm{CaAl}}_{2}$ are presented. For the amorphous alloys the calculations are based on r…
We report an electrolyte-electroreflectance (EER) study of a ${\mathrm{RuS}}_{2}$ single crystal in the energy range 1.9--5.1 eV. The EER spectrum exhibits sharp structure in the vicinity of interband transitions. Transition energies are determined accurately. Photocurrent versus wavelength measurements show an indire…