Materials Literature
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Structural phase transitions in perovskite crystals involving displacements of the oxygen octahedra due to the condensation of linear combinations of the triply degenerate ${\ensuremath{\Gamma}}_{25}$ modes at the $R$ corner of the Brillouin zone are discussed with the help of a model Hamiltonian. These distortions ar…
The vaporization of uranium mononitride UN has been investigated by the Knudsen effusion technique in combination with a mass spectrometer. The vaporization occurs incongruently by preferential loss of nitrogen forming the two-phase system nitrogen-saturated liquid uranium–uranium-saturated nonstoichiometric uranium m…
The matrix isolation of silicon monoxide vapor leads to the formation of at least three distinct species: SiO, Si2O2, and Si3O3. Infrared absorptions for these molecules are observed at 1223.9 cm−1 (Si16O); 804.7, 766.3 cm−1 (Si216O2); 972.6, 631.5, 312.0 cm−1 (Si316O3). Equations are given for the in-plane vibrations…
Generalized x-ray scattering factors have been determined from the evaluation of Fourier transforms of atomic-orbital products. Self-consistent-field atomic orbitals for first-row atoms have been studied. Analytical scattering expressions for rapid evaluation on digital computers have been developed. Scattering factor…
We construct a dielectric two-band model which describes and predicts ionization potentials and electronic band structures of binary compounds ${A}_{N}{B}_{8\ensuremath{-}N}$. Only the density and dielectrically defined electronegativity difference are required as input data. The method is applied to 19 tetrahedrally…
Electrical conductivity, differential thermal analysis, ac Hall effect, and x-ray diffraction measurements were used to investigate the low-temperature behavior of flux-grown single crystals of the titanium oxides. Monoclinic ${\mathrm{Ti}}_{3}$${\mathrm{O}}_{5}$ and the triclinic Magn\'eli phases ${\mathrm{Ti}}_{4}$$…
The magnetic electron distribution in Mn${\mathrm{Pt}}_{3}$ ferromagnetic alloy has been determined by the polarized neutron technique. The Mn form factor in the ferromagnetic state has been determined and agrees closely with the theoretical one calculated for the free atom. The magnetic moments are $(3.64\ifmmode\pm\…
The contributions of internal strain and charge redistribution to the piezoelectric constants of tetrahedrally coordinated ${A}^{N}{B}^{8\ensuremath{-}N}$ crystals are discussed. It is shown that the reversal of sign of the piezoelectric constant on going from $N=1 \mathrm{and} 2$ to $N=3$ can be explained quantitativ…
The temperature dependence of the longitudinal and the shear sound-wave velocity along the [100] axis in ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ is presented. The longitudinal velocity exhibits an anomaly at 130\ifmmode^\circ\else\textdegree\fi{}K, where there is an easy-axis change from the [111] to the [100]. Both she…
The Jahn-Teller coupling of a triplet state in cubic surroundings to both ${E}_{g}$ and ${T}_{2g}$ modes of vibration can lead to a vibronic ground state that includes both tetragonal and trigonal distortions if the energy difference between the static distortions is small. A simple model is set up to study the proper…
This paper reports optical and magnetic properties of tetramethyl ammonium manganese trichloride, [${(\mathrm{C}{\mathrm{H}}_{3})}_{4}$N][Mn${\mathrm{Cl}}_{3}$]. Magnetically, the system is one of very weakly interacting chains of ${\mathrm{Mn}}^{++}$ ions. Magnetic-susceptibility measurements are given from room temp…
The ferrimagnetic spinels ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$, Ni${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$, Co${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$, Mn${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$, and Mg${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$ have been prepared and studied with the M\"ossbauer-effect technique over a wide temper…
Within a two-state formalism, a systematic procedure is developed for deriving the difference between the gerade and ungerade state potentials from resonant charge-exchange total cross sections. It is shown that three potential constants may be derived from (i) the relative monotonic velocity dependence of the cross s…
A method is described for the complete calculation of electronic energies in crystalline solids without approximating overlap, electron-repulsion, or exchange contributions. The practicality of the method is confirmed by preliminary results, which also indicate reasons for the considerable success of independent-elect…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRates of substitution of some diacidobis(ethylenediamine)iridium(III) complexesRobert A. Bauer and Fred BasoloCite this: Inorg. Chem. 1969, 8, 11, 2237–2242Publication Date (Print):November 1, 1969Publication History Published online1 May 2002Published inissue 1 November 196…
Basswood, eastern white pine, and sugar maple samples were impregnated with three different monomers, using various treatment conditions, and cured by the catalyst-heat technique. Monomers were t-butyl styrene, Heilman-Gulf epoxy monomer, and methyl methacrylate. Hygroscopicity, dimensional stability, static bending,…
Abstract The exchange complex of two organic soils from the Sacramento‐San Joaquin delta of California was easily saturated with calcium. However, the Ca 2+ of the calcium‐saturated soil was difficult to replace with Na + even when the calcium‐saturated soils were leached with 1 N NaCl. Exchange of the Ca 2+ by Na + w…
The eflect of porosity on the thermal conductivity of sintered ThO2 of densities ranging from 90 to 95% of theoretical density was investigated at 20°C. The thermal conductivity was determined by means of laser pulse. Discrepancies were observed between the experimental results and the relation derived by Loeb. This d…
The synthesis of zircon from ZrO 2 and SiO 2 at fixed temperatures from 1200° to 1400°C was studied as a function of time up to 16 h. Quantitative X‐ray diffraction was used to estimate the phases in the product. Quartz transforms to cristobalite through an amorphous transitional phase. Assuming a homogeneous reaction…
Abstract The cation exchange capacities versus pH of 12 soils from 10 states were determined by measuring Ba adsorbed by the unlimed soils from buffered solutions adjusted from pH 2.5 to 8.0, and K adsorbed from 1.0 N KCl by incrementally limed (and incubated) soils. The contributions of organic matter and clay to soi…