A low temperature phase of (NH4)2TeBr6
X-Ray diffraction has shown the existence of a low temperature tetragonal phase of (NH 4 ) 2 TeBr 6 having space group P4/mnc(D 4h 6 ) with a = 7.501, c = 10.765 Å.
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Electronic Structure of Luminescence Centers of ZnS Phosphors Activated with Impurity Ions of s2 Configuration. II. ZnS:Pb (Zinc-Blende) Phosphors
A, B , and C bands with peaks at about 4910, 4220, and 3990 Å (mean values for split subbands at 77°K), respectively, were found in the excitation or reflection spectra of visible region of ZnS:Pb (zinc-blende) phosphors. These bands were analyzed by means of Sugano's molecular-orbital theory and identified unambiguou…
Quasiequilibrium Treatment of Gas–Solid Reactions. I. Evaporation Rates of Volatile Species Formed in the Reaction of O2 with W, Mo, and C
A quasiequilibrium treatment of heterogeneous reactions is used to compute the rates of evaporation (desorption) of volatile species formed in the reaction of gaseous O2 with solid tungsten, molybdenum, and graphite under conditions of low pressure and high temperature. The results are compared with existing mass–spec…
Theory of a Structural Phase Transition in Perovskite-Type Crystals
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…
Vaporization of Uranium Mononitride and Heat of Sublimation of Uranium
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…
Matrix Isolation Studies of Group-IV Oxides. I. Infrared Spectra and Structures of SiO, Si2O2, and Si3O3
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
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…
Quantum Dielectric Theory of Electronegativity in Covalent Systems. II. Ionization Potentials and Interband Transition Energies
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 Properties of Some Titanium Oxides
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}$${\mathrm{O}}_{5}$ and the triclinic Magn\'eli phases ${\mathrm{Ti}}_{4}$$…
Magnetization Distribution in Ferromagnetic MnPt3by a Polarized-Neutron Investigation
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\…
Charge Redistribution and Piezoelectric Constants
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…
Elastic and Magnetoelastic Effects in Magnetite
The temperature dependence of the longitudinal and the shear sound-wave velocity along the [100] axis in ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ is presented. The longitudinal velocity exhibits an anomaly at 130\ifmmode^\circ\else\textdegree\fi{}K, where there is an easy-axis change from the [111] to the [100]. Both she…
Dynamic Jahn-Teller Effect in an Orbital Triplet State Coupled to BothEgandT2σVibrations
The Jahn-Teller coupling of a triplet state in cubic surroundings to both ${E}_{g}$ and ${T}_{2g}$ modes of vibration can lead to a vibronic ground state that includes both tetragonal and trigonal distortions if the energy difference between the static distortions is small. A simple model is set up to study the proper…
Linear-Chain Antiferromagnetism in [(CH3)4N] [MnCl3]
This paper reports optical and magnetic properties of tetramethyl ammonium manganese trichloride, [${(\mathrm{C}{\mathrm{H}}_{3})}_{4}$N][Mn${\mathrm{Cl}}_{3}$]. Magnetically, the system is one of very weakly interacting chains of ${\mathrm{Mn}}^{++}$ ions. Magnetic-susceptibility measurements are given from room temp…
Mössbauer Study of Several Ferrimagnetic Spinels
The ferrimagnetic spinels ${\mathrm{Fe}}_{3}$${\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…
Determination of the Difference Potential from Resonant Charge-Exchange Total Cross Sections: Analysis of RB+-Rb andCs+-Cs
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…
Complete Calculations of the Electronic Energies of Solids
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…
Rates of substitution of some diacidobis(ethylenediamine)iridium(III) complexes
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…
NEW MONOMERS USED IN MAKING WOOD PLASTICS
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,…
Sodium‐Calcium Exchange Behavior in Organic Soils
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…