Materials Literature
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The infrared lattice spectra from 700 to 50 cm−1 of eight cubic rare earth oxides are reported. It is evident from these data that the crystal structure determines the frequency position, and clearly shows the effect of the lanthanide contraction in this series of compounds.
The development of scale cells in insects has been studied from the appearance of the first cytoplasmic projection which forms the scale rudiment. This rudiment contains numerous longitudinally oriented microtubules throughout. Immediately under its outer surface lie a series of adjacent but distinct bundles of longit…
The aim of this paper is to give a qualitative account of the electrical properties of liquid divalent metals for which the density of states falls below the free electron value at the Fermi surface. It is argued that if this happens in the crystalline state it will also happen in the liquid, that this is so in mercur…
The electrical conductivity, the magnetoresistance, the Hall coefficient and the thermoelectric power of single crystal graphite are theoretically calculated as functions of the temperature and magnetic field intensity in the region where lattice scattering is dominant. The values of the electron-phonon coupling const…
Experimentally measured effective vacuum thermionic electron work functions are reported for well outgassed polycrystalline surfaces of beryllium (3.67 eV), titanium (3.6 to 4.3 eV), chromium (3.90 eV), iron (4.47 eV), nickel (4.41 eV), copper (4.42 eV), platinum (5.6 to 5.8 eV), strongly (210) oriented, and 304 stain…
The parameters in the crystal structure of α-GeTe were determined by least-squares analysis of intensity data obtained with an automatic x-ray powder diffractometer. The rhombohedral cell containing 4 Ge and 4 Te atoms has a=5.996±0.001 Å, α=88.18°, and the single atom-position parameter x=0.237±0.002. The displacemen…
Fluorescence quenching effects caused by multipolar energy-transfer interactions between rare-earth ions are examined. Transfer between remote ions by way of transitions that are matched in energy appears to be essentially dependent upon concentration alone (e.g., Sm3+ self-quenching) while transfer by non-resonant me…
Abstract Using synthetic near-ideal graphite obtained by hot-pressing and annealing pyrolytic material, we have prepared graphite nitrates from the first to the fourth sequence, under controlled conditions. For the first sequence compound, present determinations on form I (room temperature) agree with previous publica…
The infrared spectrum of hydrogen bonded HN3 dimers in solid nitrogen has been determined. A dimer band at 387 cm−1, assigned to the torsional distortion of the hydrogen bond, indicates the dimer has an open, not a cyclic structure. The hydrogen bond bending force constant is 0.09 mdyn/Å. The hydrogen bond frequency s…
The magnetocrystalline anisotropy constant ${K}_{1}$ of iron was determined from static torque measurements on a {001} single-crystal disk at fields between 3000 and 18 000 Oe, and at temperatures between 77 and 900\ifmmode^\circ\else\textdegree\fi{}K. It was found that (i) $\frac{(\frac{\ensuremath{\partial}{K}_{1}}{…
(NH 4 ) 2 TeBr 6 and Cs 2 TeBr 6 crystals have the cubic K 2 PtCl 6 structure with space group: [Formula: see text] with a 0 = 10.728 ± 0.003 Å and 10.918 ± 0.002 Å respectively. The positional coordinate of the bromine atom, and the anisotropic temperature factors of all atoms in the unit cell, have been refined for…
Paramagnetic resonance measurements have been carried out at 78° and at 4°K on Cu2+ ions diluted in single crystals of CdWO4, ZnWO4, and MgWO4. The g factors and the hyperfine interaction with the copper nucleus have been determined. From this experimental data the ground-state wavefunction of the Cu2+ ion has been co…
ESR and optical measurements have been made on the lowest triplet state of a series of phenyl s-triazines and polyphenyl benzenes. The features of the phosphorescence spectra and the value of the zero-field splitting parameters of these azines and their hydrocarbon analogs leads to the assignment of the lowest triplet…
The ferroelectric behavior of triglycine sulfate, which can be considered the best example of a nearly ideal second-order-transition ferroelectric, has been analyzed. Accurate measurements of the temperature dependence of spontaneous polarization and dielectric constant in the vicinity of the phase transition from the…
The two-vibrational-mode model proposed by Toyozawa and Mahr to account for the Urbach rule is considered both in the semiclassical approximation and in the full quantum theory. The semiclassical line shape accounts for both the exponential Urbach tail and the central Gaussian region of the absorption band. Quantum mo…
Photoelectric yield and energy distributions are given for clean-cleaved and cesium-covered (111) surfaces of silicon and germanium. A monolayer of cesium lowers the work function of each to \ensuremath{\sim}1.6 eV and reveals detailed structure in both yield and distributions. This structure is directly related to th…
Optical absorption in stoichiometric and reduced, semiconducting single crystals of SrTi${\mathrm{O}}_{3}$ has been measured in the region 0.4-5 \ensuremath{\mu} at room temperature and 77\ifmmode^\circ\else\textdegree\fi{}K. Reduced crystals show a rapid increase of absorption with increasing wavelength beyond 0.6 \e…
By representing the effective-tension term of a dislocation (string model) as a power series in displacement gradients, and retaining the first nonlinear term, expressions for the amplitudes of the second and third harmonics of an ultrasonic wave introduced into a solid containing mobile dislocations are obtained. In…
The lattice parameters, atomic volume, nearest-neighbor interatomic distance, axial ratio, and coefficients of thermal expansion of zirconium are reported over the temperature range 4.2 to 1130\ifmmode^\circ\else\textdegree\fi{}K. The data were obtained from single crystals, using a precision x-ray diffraction techniq…
The electrical conductivity and the Seebeck effect are measured in the temperature region of 100 to 1300\ifmmode^\circ\else\textdegree\fi{}K in NiO doped with Li. From the results it is concluded that the mobility of the charge carriers involves no activation energy. The temperature dependence of the conductivity is a…