Materials Literature
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The connection between intermolecular potential energies and the unit cell vibrational frequencies in molecular crystals is summarized in Sec. I. Details of the treatment of potentials which can be written as functions of intermolecular atom-atom distances are developed. The frequencies of vibration of methyl chloride…
The system $$CaCO_{3}-MgCO_{3}-MnCO_{3}$$ was investigated at temperatures of 500°, 600°, 700°, and 800° C. and 10 kilobars total pressure. Three two-phase areas and one three-phase triangle are observed, and an additional two-phase area is inferred. At 500° C. there are two single-phase regions, which enlarge and mer…
Single crystals of NiO have been annealed and stressed at room temperature to sweep out twin boundaries. Neutron diffraction and rotational torque studies have been made on a crystal which had only 1.3% of the twin orientation. The ferromagnetic sheet structure originally proposed in which the atomic moments lie in(11…
A study of the solid solution of TiO 2 , Fe 2 O 3 , and Cr 2 0 3 in mullite was made by measuring the changes in lattice parameters and unit‐cell volume. Synthetic mullite (3O 3 ‐2SiO 2 ) was reacted with up to 12 weight % of the oxides at temperatures ranging from 1000° to 17000C. The approximate minimum temperature…
Article Die Zustandsbilder Gallium—Wismut und Gallium—Quecksilber, Vergleich der Koexistenzkurven mit den Theorien der Entmischung was published on May 1, 1960 in the journal Zeitschrift für Physikalische Chemie (volume 24, issue 3_4).
Partial pressures of the gaseous oxides MoO, MoO2, MoO3, WO, WO2, WO3, UO, UO2, and UO3 in the systems Mo–Al2O3 and U–Al2O3 have been measured by mass spectrometric methods. The vapor pressure of uranium has also been determined. The reaction enthalpies derived from these measurements are: Reaction ΔH0ο kcal/moleMoO(g…
The present report is concerned with an experimental investigation of the influence of free carriers on the optical absorption of SnO 2 , which is an almost perfect insulator in its stoichiometric composition but can be endowed with a semi-metallic conductivity when synthesized by the spraying method. In order to inve…
The evaporation of alumina under nearly neutral conditions in tungsten and molybdenum Knudsen cells has been investigated by mass spectrometric methods. The atomization energies of the gaseous molecules are D0o(AlO) = 115±5 kcal/mole; D0o(Al2O) = 245±7 kcal/mole; D0o(Al2O2) = 365±7 kcal/mole.
Abstract The thickness of single crystal lamellae of polyethylene, crystallized from solution, is found to increase greatly during annealing at temperatures above 110°C. The change is observed with small‐angle x‐ray diffraction and electron microscopy. The increase in thickness of the lamellae takes place at the expen…
Nickel films varying in thickness from 300 to 15A were prepared by evaporation on glass substrates in a vacuum sufficiently high to prevent gas adsorption on the film during preparation and measurement. Their magnetization was measured as a function of field up to 10000 oe using a vacuum torsion magnetometer. The satu…
Abstract The results obtained with free radical traps in a variety of curing systems for SBR rubber give evidence for both polar and free radical mechanisms. There is apparently no one mechanism even for sulfur vulcanization and the relative free radical or polar character of the crosslinking reaction varies over a br…
Abstract Soils and micaceous minerals were extracted with NaBPh 4 ‐salt solutions to determine the ease with which nonexchangeable K can be removed when the blocking effect of fixable cations is reduced. Essentially all of the K in vermiculite, 12% of the K in muscovite and as much as 47% of the K in illite was extrac…
The practical application of the field emission electron source has heretofore been impeded by insufficient reliability. Instability (i.e., changes in emitted current at a fixed applied voltage) results from changes in the cold cathode surface associated with contamination and sputtering. The cold clean cathode is sho…
A probe method has been devised for measuring potentials in d-c corona fields which are uniform for a short distance in one direction. In unipolar corona, a probe supported by perfect insulators assumes a potential sufficiently above the space so that no more ions can reach the probe. For a cylindrical probe with its…
The magnetic anisotropy and magnetostriction of single crystals of alloys between 25 weight % and 59 weight % cobalt in iron have been determined in the disordered and ordered states. The magnetostrictionis large and positive for all alloys in both states of order (up to 150×10−6 for λ100 and 40×10−6 for λ111). The ma…
This paper discusses the response of the magnetization in a small ferrimagnetic ellipsoid, magnetized in an arbitrary direction and excited by spatially uniform microwave magnetic fields, when a typical spin wave is present. The generalized Kittel frequency is given, and possible frequency generation processes appropr…
Measurements of the characteristic electron energy loss spectra of aluminum and magnesium were made (in a reflection experiment) during oxidation of a fresh evaporated layer of either metal. It was found that surface oxidation results in the rapid disappearance of the low-lying energy losses (10.3 ev in aluminum and 7…
The observations reported here of the electron spin resonance in quite perfect single crystals of graphite clearly establish that the resonance arises from mobile charge carriers. The line shape is of the Dysonian form which is characteristic of conduction electron spin resonance in metals. The intensity of the spin r…
Abstract The structural configurations that distinguish the atactic phase from the isotactic phase give rise to infrared spectra characteristic of each phase. Since these differences are quite significant, a method is proposed with which the isotacticity can be determined. The relation between the isotactic phase and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudies on Metastable States of Porphyrins. II. Spectra and Decay Kinetics of Tetraphenylporphine, Zinc Tetraphenylporphine and Bacteriochlorophyll1Lauri Pekkarinen and Henry LinschitzCite this: J. Am. Chem. Soc. 1960, 82, 10, 2407–2411Publication Date (Print):May 1, 1960Pub…