Materials Literature
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A natural single crystal of zircon, ZrSiO(4,) from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10(16) and 0.8 x 10(16) al…
This book introduces the reader to methods of selecting materials for engineering applications. With the rapid growth in the variety of manufacturing materials available, the choice of the optimum material for an engineering design is of increasing importance and difficulty. Materials have to be chosen that satisfy se…
We describe the linear and nonlinear properties of a new polymer composite, which uses a ferroelectric PVDF copolymer host in which an optically nonlinear low-molecularweight guest is dissolved and subsequently aligned using a room-temperature poling process. We have measured the frequency-doubling coefficient d33 of…
The disadvantage of electrodeposited Cu2O films on opaque substrates regarding the measurement of their transmittance and optical absorption coefficient is overcome by a successful and reliable procedure of transferring the films onto glass slides. The method can be applied to other electrodeposited films. An accurate…
We investigate how the initial formation of an oxide layer on a metal surface can effect the further incorporation of oxygen into the metal. In particular, we show that the formation of NbO on a Nb surface dramatically increases the potential barrier for oxygen incorporation. On Cu the formation of an oxide layer redu…
The formation of hydroxyl due to reaction of a silica glass made by the modified chemical vapor deposition process with hydrogen has been studied for temperatures between 200 and 900 °C. The glass is treated under 1 atm of hydrogen, which diffuses into and reacts with the glass. For treatment temperatures between 900…
We examine two wave functions which have recently been found for electrons in quasiperiodic systems, and which can be shown to satisfy an exact self-similarity relation---closely related to the self-similarity of the quasiperiodic lattice itself. The first wave function is for the ground state of an electron on a two-…
Au-dessus de la temperature de transformation de phase antiferro-electrique (Tc=148 K), NH 4 H 2 PO 3 cristallise avec le groupe d'espace I42d (R=1,7%). En dessous de Tc, le compose cristallise avec le groupe d'espace P2 1 2 1 2 1 (R=3,4%)
Analogous to the treatment of the spin-correlated crystal field, a new type of lanthanide correlation crystal field, which depends on the relative orientations of the individual 4f electron orbital angular momenta and the total orbital angular momentum, is postulated. Associated sets of parameters have been obtained f…
Through observation of the optical second harmonic generation, the stress-induced ferroelectric transition temperature of SrTiO 3 was determined as a function of the applied uniaxial stress along the [100] direction. The characteristics of the temperature-stress phase diagram are in agreement with the theoretical pred…
The spectra of 3 d photoemission, valence photoemission and BIS in Ce 2 O 3 are analyzed theoretically by using the filled band Anderson model. The calculated spectra are in satisfactory agreement with experimental data by choosing appropriately the parameter values in the model. The characteristic features of these s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnalysis of synthetic polymersCharles G. Smith, Richard A. Nyquist, Nels H. Mahle, Patrick B. Smith, Steven J. Martin, and Andrew J. PasztorCite this: Anal. Chem. 1987, 59, 12, 119–141Publication Date (Print):June 15, 1987Publication History Published online1 May 2002Publish…
A systematic study of the effects of Co substitution on the crystal structure and magnetic anisotropy of Y2Fe14−xCoxB and Nd2Fe14−xCoxB has been carried out in order to clarify the different roles and contributions to the anisotropy of both rare earth and transition metals. The substitution of Co leads to an enhanceme…
Electron-nuclear double-resonance (ENDOR) spectra of undoped cis-rich (CH${)}_{\mathrm{x}}$ at low temperatures are consistent with the spin-density distribution of the soliton predicted for a finite on-site Coulomb energy. The ratio of the peak value of the negative spin density \ensuremath{\rho}(1) to that of the po…
The hyperfine splitting of the oxygen-vacancy center resonance in amorphous ${\mathrm{SiO}}_{2}$ has been measured as a function of density in samples densified under pressure at high temperature. Densification of \ensuremath{\sim}24% is found to produce an increase in the isotropic hyperfine coupling constant of 11.5…
The structural and electronic properties of the complex tetrahedral structures B-8 (or ``BC8,'' bcc with 8 atoms per cell) and T-12 (or ``ST12,'' simple tetragonal with 12 atoms per cell) phases of silicon and carbon are computed with ab initio density-functional calculations of the energy, pressure, and enthalpy. For…
ac impedance techniques have been used to characterize ceramic samples of LiTaO3 and the solid solutions Li1−5xTa1+xO3 as a function of temperature in the range 350–800 °C. LiTaO3 has a low conductivity and the principal charge carriers appear to be electrons. At temperatures well removed from its ferroelectric Curie…
A simple, universal model for structural properties of sp-bonded semiconductors and insulators is presented. The model elucidates the physical mechanisms determining the chemical trends and predicts semiquantitatively the stable crystal structures, bond lengths, bulk moduli, transition pressures of structural phase tr…
Using the Stillinger-Weber potential we explored the liquid, crystal, and amorphous phase diagram of silicon by molecular dynamics. We obtain the chemical potential of the crystal by following the crystal-vapor coexistence curve from the T=0 harmonic solid up to the melting point. The liquid free energy is found by re…
Recently, nanometer-sized crystalline materials have been proposed to represent a new solid-state structure which exhibits neither long-range order (like crystals) nor short-range order (like glasses). It was the purpose of this study to test this idea by x-ray diffraction experiments. Nanometer-sized crystalline mate…