Materials Literature
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Abstract The mechanism of the conductance of the electric current through a carbon black dispersion is still a problem which has not been completely solved. Rubber is an insulator and forms a homogeneous liquid phase, while carbon black is a semi-conductor and forms a dispersible solid phase. Mixtures of these two sho…
Synopsis Starting from the basis that the direction of sliding of one particle relative to another is, in general, inclined at an angle to the direction of the applied shear stress, a theory is developed to account for the difference between peak and residual stresses in terms of the volume expansion of the mass durin…
Current theories of "single-domain" ferromagnetic particles compare the free energy in a state of uniform magnetization with that in an arbitrarily chosen state of nonuniform magnetization. In this paper, the comparison is made between an initial uniform state and all neighboring states, uniform or nonuniform, as an i…
A study of the effect of Li substitution on the electrical properties of the oxides MnO, CoO, NiO, and CuO has been made. It has been found that (1) the activation energy for conduction increases abruptly near the antiferromagnetic Curie point; (2) as Li is added the activation energy and resistivity initially decreas…
Mixtures of 0.8 moles of CaO per mole of SiO 2 plus Al 2 O 3 were prepared from lime, kaolin, and tripoli (microcrystalline quartz); the amounts of SiO 2 to Al 2 O 3 were varied to give from 0.2 to 20.7% Al 2 O 3 by weight of dry solids. After hydrothermal treatment (170° to 175°C.), the products were examined by diff…
The experiment reported in this paper was designed to obtain data on the dynamics of a nonrotating, conical-nosed projectile penetrating randomly-packed sand. Position versus time measurements for the projectile in sand were obtained by means of a photographic-electronic chronograph developed for the purpose. The stri…
Abstract One of the more important advances in rubber science during the past twenty years has been the development of quantitative theories describing the elastic properties of pure-gum vulcanized rubbers. As a result it is now possible to account for their equilibrium stress-strain behavior with considerable success…
The present paper investigates by experiment and theory the mechanisms governing work-hardening, work-softening and slipband formation in face-centred cubic metals. The rapid hardening stage (stage II) of the stress-strain curve is investigated by flow-stress measurements at different temperatures, combined tensile an…
Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation B. D. Cullity, R. Smoluchowski; Elements of X‐Ray Diffraction. Physics Today 1 March 1957; 10 (3): 50. https://doi.org/10.1063/1.3060306 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends…
A theory is presented which describes the development of surface grooves at the grain boundaries of a heated polycrystal. The mechanisms of evaporation-condensation and surface diffusion are discussed with the use of the Gibbs-Thompson formula and the assumption that the properties of an interface do not depend on its…
The details of an observed absorption spectrum are shown to depend upon the thickness of the absorber. This effect is present, at least in principle, regardless of the type of radiation involved. It is discussed here specifically for x-rays, and specifically for the neighborhood of an absorption edge. Measurements of…
A modification of the diffraction theory for a disordered substitutional solid solution containing atoms of different sizes gives a more accurate and simpler expression for the size effect diffuse scattering. A comparison of the theory with measurements of the diffuse scattering for Cu/sub 3/Au near hkl = 200 shows go…
Thermoelectric power measurements have been performed on powdered nickel oxide in the temperature range 60–220°C, under different gas atmospheres. These include: oxygen, hydrogen, carbon monoxide, carbon dioxide, nitrous oxide, helium, and water vapor, at different partial pressures. The extent and direction of the ob…
The ability to form a glass, i.e., the ability to form bonds which lead to a vitreous network, appears periodically in the classification chart of the elements. Thus simple glasses containing only one kind of atom are formed by the elements of Group VI of the periodic table (O, S, Se, and Te). Only these elements are…
Compressional creep tests were run on single crystals oriented so that the direction of compression was along the c axis. Two activation energies of creep were found: approximately 24 500 cal/mole above 120°C and 12 000 cal/mole below this temperature.
The heat capacity of α-quartz has been computed over the temperature range 10–700°K, and that of vitreous silica from 10° to 900°K. Debye θ's obtained from the T3 law below 10° were used for the ``translational'' degrees of freedom, and recent infrared and Raman data for the other frequencies. Cp—Cv was negligible for…
The details of the phonon scattering produced by point imperfections in insulating crystals has been determined from measurements of the thermal conductivity of six single crystals of KCl from 3\ifmmode^\circ\else\textdegree\fi{}K to 30\ifmmode^\circ\else\textdegree\fi{}K as a function of the concentration of point im…
Abstract Muscovite and K-feldspar (adularia) were dry-ground to — 200/inch particles, which were suspended in water. These suspensions were “titrated” with KCl, and the pH was recorded as a function of KCl concentration and temperature. The results indicate that muscovite and adularia react with water to produce a sur…
Abstract An extensive survey of clay mineral relationships in the subsurface Wilcox formation (Eocene) has shown progressive diagenetic conversions with depth. Montmorillonite, a common constituent of Wilcox outcrop material, becomes loss evident below 3000 ft and is not normally found in an unmixed state below the 90…
The reader is introduced to some of the main points of semiconductor phenomena. Concepts of wave properties of electrons, discrete energy levels, free electrons in metals, and band theory of solids, show how semiconductors differ from metals and insulators. This is followed by a discussion of doping to create impurity…