Materials Literature
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Salicylic acid forms a 1:1 complex with boric acid, the reaction involving both the fully protonated ligand, and the salicylate ion. The kinetics of this reaction have been studied by the stopped-flow method. The stability constant for the reaction involving salicylate ion has been calculated from measurements of the…
We have measured the Raman spectra of AgBr and AgCl in both the high-temperature solid and the melt. The melt spectra are strikingly similar to the spectrum of the superionic conductor $\ensuremath{\alpha}\ensuremath{-}\mathrm{AgI}$. We have found that second-order Raman scattering from short-wavelength vibrations ("z…
Raman measurements are reported in the superionic conductor AgI far below and above the transition temperature ${T}_{c}=147$\ifmmode^\circ\else\textdegree\fi{}C. At ${T}_{c}$, the crystal structure changes from the low-temperature wurtzite phase to a disordered-defect body-centered cubic structure ($\ensuremath{\alpha…
The second- and third-order hyperpolarizabilities of various mono- and meta-disubstituted benzene derivatives have been measured in the liquid state by simultaneous use of static-field induced second-harmonic generation and tunable four-wave mixing. For the vector part of the second-order optical nonlinearity comparis…
First- and second-order Raman-scattering measurements have been performed in the crystalline ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Si}}_{x}$ alloy series from low frequencies (\ensuremath{\sim} 40 ${\mathrm{cm}}^{\ensuremath{-}1}$) to high frequencies (\ensuremath{\sim} 1100 ${\mathrm{cm}}^{\ensuremath{-}1}$). The…
The interaction of electrons with librational modes is proposed as the basic mechanism responsible for the observed temperature behavior of the resistivity in tetrathiafulvalene-tetracyanoquinodimethane. This mechanism also gives a reasonable estimate of the relaxation time.
X-ray diffuse-scattering studies on tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) above the 54-K phase transitions reveal two types of one-dimensional scattering at the wave vector $0.295{b}^{*}$ (earlier assigned to the $2{k}_{F}$ wave vector) and at $0.59{b}^{*}$ (corresponding to twice the former wave vect…
The cascade in the secondary-electron emission from atomically clean and atomically characterized surfaces of metals has been studied in the energy region of shortest inelastic mean free paths ($10 \mathrm{eV}\ensuremath{\lesssim}E\ensuremath{\lesssim}1000 \mathrm{eV}$). Specimen surfaces were cleaned in situ and char…
The dependence of the electron intersubband resonance on temperature has been studied between 4.2 and 130 K for photon energies 10.45, 15.81, and 44.32 meV. At the highest energy, distinct transitions from the ground state to each of the next three higher-lying levels (i.e., the 0\ensuremath{\rightarrow}1, 0\ensuremat…
The zone-center optical phonons of layer materials GaSe, GaTe, and their solid solutions are studied by means of Raman scattering. Most of the structure in the hitherto unstudied spectrum of GaTe is identified by following their evolution in the solid solutions and relating them to already known bands in GaSe. Increas…
The dc conductivities of seven concentrated aqueous acids, and the electrical relaxation properties of four of these, are reported. At the glass transition temperature Tg, as determined by differential thermal analysis, the dc conductivities increase with Tg for the individual acids, according to an Arrhenius function…
Abstract Measurements have been made of the viscoelastic properties of a range of low-molecular-mass polystyrenes each having a narrow molecular mass distribution. Several experimental techniques using alternating shear have been employed covering the frequency range 10-2 Hz to 450 MHz and at temperatures from the gla…
The infrared reflection spectra of $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ were measured in the energy range 30-1000 ${\mathrm{cm}}^{\ensuremath{-}1}$; two optical-phonon modes were observed for extraordinary ray; four optical-phonon modes were observed for ordinary ray. The optical consta…
Vitreous LiNbO3 and LiTaO3 have been prepared by roller quenching these compositions from the melt. The transparent glasses exhibit pronounced dielectric anomalies with peaks of ε≳105 close to the crystallization temperature which are not characteristic of the crystalline phase. Pyroelectricity is induced after coolin…
Polarized low-frequency Raman and Brillouin spectra of the chalcogenide glasses ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, Ge${\mathrm{S}}_{2}$, Ge${\mathrm{Se}}_{2}$, and ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$ and the glass alloy system ${({\mathrm{As}}_{2}{\mathrm{S}}_{3})}_{1\ensuremath{-}x}{(\mathrm{Ge}{\mathrm{S}}_{2…
The retarded polarization in an ensemble of ultrafine particles is incorporated in the Maxwell-Garnett theory for the average dielectric permeability of a system of randomly distributed particles. This theory is applied to the optical absorption of ultrafine silver particles in a glass matrix. For particles with mean…
Hopping motion is considered in a linear chain containing an arbitrary density of particles that are not allowed to hop to occupied sites. The general case of two inequivalent lattice sites $A$ and $B$ is treated. Transition-rate equations are solved by Monte Carlo simulation and, where possible, by analytic technique…
We have carried out a high-resolution x-ray-scattering study of the critical fluctuations in the nematic phase associated with the nematic-smectic-$A$ transition in N-$p$-cyanobenzylidene-$p$-octyloxyanilene (CBOOA). It is shown that for $8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}\ensuremath{\lesssim}\f…
A downfield shift of proton signals up to 9 ppm is induced in the 1H NMR spectra of juvenile hormone I (methyl 3,11-dimethyl-10,11-cis-epoxy-7-ethyl-2-trans, 6-trans-tridecadienoate) and III (methyl 10,11-epoxy-2-trans, 6-trans-farnesoate) by the lanthanide complex Eu(fod)3. A plot of induced shift vs the ratio of [LS…
Abstract High molecular weight poly(ethylene oxalate) with fiber‐forming properties was obtained from oxalic acid and ethylene glycol. The process was carried out on two stages in the melt. A new method was used for aliphatic oligoester synthesis in the melt, because the decomposition of oxalic acid takes place in the…