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The nature of the permanent damage retained in metals from irradiation has been investigated in somewhat greater detail than has been done in the past. The usual assumption has been that the damage in all metals consists chiefly of interstitial-vacancy pairs. The model presented in this paper reduces to this picture f…
Forty-six standard x ray diffraction powder patterns are presented. Fourteen are to repiace twelve patterns already given in the x ray Powder Data File, and thirty-four are for substances not previously included. The patterns were made with a Geiger counter x ray diffractometer, using samples of high purity. The d-val…
The nucleation and growth of ferroelectric domains in barium titanate have been studied as a function of applied electric field and temperature. The optical and electrical measurements were made on thin single-crystal plates normal to $c$, the polar direction. When the electric field applied along this direction is re…
Relations between the elastic and plastic properties of pure polycrystalline metals are discussed and a systematic relation between shear modulus, Burgers vector and plastic shear strength of metals possessing the same lattice structure is proposed. In addition reasons are given for believing that in a limited tempera…
A review of the measured A1-O and Si-O distances leads to the values A1-O = 1.780.02 /~ and Si-O ----1-600.01 A. These values are of use in locating the positions of A1 and Si atoms in felspar or other structures by accurate measurements of distances in oxygen tetrahedra.
By means of recent electron microscopes, such as the three-stage electron microscope (le Peele, 1947; see also Haine, Page & Garfitt, 1950) and the shadow-microscope (Hillier & Baker, 1946), it is possible to observe a micrograph and a diffraction diagram from the same small object. This extends the structural study o…
The crystal structure of CsI a has been determined by X-ray analysis. Space group: P21/a; 4CsI 4 per unit cell. The signs of 60 out of the 71 observed hOl structure factors could be calculated directly from inequalities. Inequalities were not useful in the [001] projection, but a first approximation could be obtained…
Elastic scattering measurements have been carried out with electrons in ${\mathrm{Au}}^{197}$ at energies of 84, 126, 154, and 183 Mev and in ${\mathrm{Pb}}^{208}$ at 84, 153, and 186 Mev. Diffraction effects are observed which appear to vary with momentum and angular position as if a fundamental parameter $psin(\frac…
Both the current density and the distribution in energy of electrons emitted from metals are calculated for various combinations of temperature, applied surface electric field, and work function. A wider range of those variables than previously achieved is made possible by use of numerical integration. The integrand i…
The total number and energy distribution of backscattered electrons at 0.2-4 kev incident energy ($V$) have been measured for six elements using electrostatic retarding potential techniques. For atomic number $Z\ensuremath{\lesssim}30$, backscattering was found to be essentially independent of $V$ and almost linearly…
The details of a phase-shift calculation of high-energy electron scattering by nuclei are given, together with some preliminary results. A new method for summing the Legendre series for the Coulomb scattering amplitude is described. The results indicate that the first Born approximation does not give cross sections ac…
Abstract The electronic structure of the metallic borides MB6 is investigated theoretically by the tight-binding approximation. The stability of the crystal lattice is interpreted and it is predicted that if M is a bivalent metal the crystal should be an insulator or photoconductor, but that if M has a valency greate…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHeats of Formation of Chromium Oxide and Cadmium Oxide from Combustion CalorimetryAlla D. MahCite this: J. Am. Chem. Soc. 1954, 76, 13, 3363–3365Publication Date (Print):July 1, 1954Publication History Published online1 May 2002Published inissue 1 July 1954https://pubs.acs.o…
The thermomagnetic properties of iron selenides FeSe x with various selenium contents x were measured as functions of temperature. The thermomagnetic curves obtained belong to the ordinary Weiss type. It was also found that the magnetization at the boiling temperature of liquid nitrogen increases with the selenium con…
The optical constants n and k of Ag, Au, and Cu were determined from reflectivity and from transmissivity measurements in the wavelength range of 1μ to 3μ. Reflectivities were measured at glass-metal interfaces by a method previously described. Transmission measurements were made on samples in the thickness range of 3…
The free-electron model of a conjugated molecule is extended to apply to a metal. When each conduction electron is allowed to move freely along the set of one-dimensional lines (i.e. bonds) joining adjacent atoms, a band-structure appears. This is shown to be almost identical with the shape predicted by the convention…
Spinels of the FeFe(2−x)CrxO4,0⩽x⩽2, system have been made by reduction of the corresponding sesquioxide solid solution at 1180°C, 1100°C and 950°C and the lattice parameters determined at room temperature. The solutions of approximately stoichiometric composition have lattice parameters which vary with x in a nonline…
Abstract The modification of the amorphous/crystalline ratio in polyethylene terephthalate by copolymerization with glycols or dibasic acids usually results in a lowering of the degree of crystallinity and of melting point, and impaired physical properties. A consideration of the molecular constitution of silk fibroin…
It was found that plastic deformation takes place in periclase above 1100°C., in rutile above 600°C., and in sapphire above 900°C. The mechanism is slip; in sapphire (0001) is the slip plane and [1120] is the slip directiog. All creep curves for sapphire in tension show the same qualitative features. Each consists of…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Thermal Decomposition of Chloroform. I. Products1aGeorge P. Semeluk and Richard B. BernsteinCite this: J. Am. Chem. Soc. 1954, 76, 14, 3793–3796Publication Date (Print):July 1, 1954Publication History Published online1 May 2002Published inissue 1 July 1954https://pubs.ac…