Materials Literature
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The six complex hexagonal and rhombohedral layer structures known as hexagonal ferrites can be derived by stacking three building-block types, S , R , and T , having 2, 3, and 4 anion layers, respectively. The anion framework of R and T contains stacking reversals after each layer; the stacking sequence of R is 1·1·1,…
ZnS platelets grown from the vapor phase, bounded by (2̄11), (011̄), and (111) faces, were used. The crystals showed birefringence bands perpendicular to the [111] axis. X-ray rotation, oscillation, and Laue photographs showed that the bands are due to changes in crystal structure (cubic, hexagonal, and polytypes) and…
A possible mechanism for uniaxial anisotropy in ferromagnetic films is the magnetoelastic energy Wλ which results from the constraint imposed on the film by the substrate. Below some temperature T′ at which the mobility of the film atoms on the substrate is sufficiently low, the constraint prevents the film from defor…
Regularly interstratified chlorite-vermiculite (1:1) is found as a weathering product of chlorite in a Highfield channery silt loam soil profile in Adams County, Pennsylvania. The parent rock is greenstone, a metamorphosed basalt, composed of chlorite, epidote, alibite and ilmenite. Greenstone fragments in the soil ar…
The relation between the concentration of intrinsic paramagnetic states (the E′ centers) of silica (silica glass) produced by irradiation and the concentration of OH− ions in the silica was investigated by introducing OH− ions into silica, initially free of these ions, in a controlled manner. Optical absorption and el…
The electronic ground state wave functions in FeCO 3 and FeTiO 3 are deduced from the nuclear quadrupole coupling data. With these wave functions, the contribution of the intra atomic magnetic dipolar interaction and that of the electron orbital current effect to the internal magnetic field are calculated. A similar a…
Synthetic single crystals of Fe${\mathrm{Al}}_{2}$${\mathrm{O}}_{4}$ have been grown from the melt. Measurements of the thermal conductivity $K$ and optical absorption coefficient $\ensuremath{\alpha}$ have been made on a combination of synthetic and natural single crystals of ${\mathrm{Mg}}_{1\ensuremath{-}x}{\mathrm…
Polarized crystal-absorption spectra in the near-infrared, visible, and ultraviolet regions are reported for Cs2CuCl4. The near-infrared bands are analyzed on the basis of the known structure of the CuCl4= ion with D2d symmetry. The positions and polarizations of the bands are accounted for and the minor effcets of sp…
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
Processes occurring on the surface of iron in contact with an aqueous solution of ammonium nitrate are extremely complex. They greatly depend on the electrode potential. Chemical composition, solubility, structure, thickness, adherence and compactness of solid corrosion products vary within a wide range. Intergranular…
The structure of an authigenic maximum microcline from the Pontiskalk limestone, Switzerland, has been refined to an R value of 8.5% by a full-matrix least-squares program using 797 observed and 207 unobserved reflections. The ordering of tetrahedral Si,Al atoms is nearly complete and there is no significant structura…
Observations have been made of the domain structures on (110) [001] surfaces of grains in 3% silicon-iron sheet when stresses were applied to the sheet. The changes produced by a tension in the [110] direction or a compression in the [001] direction are similar to those observed by Dijkstra and Martius, but a more det…
Homogeneous crystals of Bi-Sb solid solutions are difficult to grow, but are important for the basic understanding of the electron transport properties and band structure of these materials. The problems arise from (1) the low melting temperature (approximately 300°C) which makes it difficult to achieve a large therma…
Slip in MgO takes place by the development of dislocation bands. Like Lüders bands, dislocation bands have undergone a fairly constant shear strain, which in this case is about 0·09 radians. Dislocation bands are nucleated usually at surface defects and widen by a dislocation sprouting (multiplication) mechanism. The…
Part I of this paper presented an analysis of an idealized polyphase hysteresis machine having a radial-flux type of rotor. In this Part II, a hysteresis machine with a circumferential-flux type of rotor is analyzed. Using a rectangular loop approximation to the B-H characteristic of the hysteresis material, the flux…
The resonant frequency in transverse vibration of natural single crystals of purified Ticonderoga graphite has been measured as a function of neutron dose. The resonant frequency increases on irradiation by a factor of two and saturates at a dose of ∼4 × 1017 n.v.t. Annealing reduces the resonant frequency again. The…
Abstract Bisphenol‐A polycarbonate gradually degrades at temperatures above 310°C. as detected by differential thermal analysis. The first stage of degradation of the dry and purified resin is induced by oxygen. In connection with oxidation, zinc stearate causes a notable degradation. This compound may act partly as a…
The Preliminary Check-list (Parke, 1953), with the three subsequent lists of additions and corrections (Parke, 1956, 1957, 1959) was intended to provide a fundamental basis for the preparation of a Flora of the British marine algae sponsored by the British Phycological Society. Changes, both taxonomic and systematic,…
The magnetic ripple of thin films with uniaxial anisotropy is calculated for the field and the magnetization lying along the easy and the hard direction of the uniaxial anisotropy. For small dispersion of the direction of magnetization, the variational principle, applied to all energy terms including the exchange, cry…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Sonolytic Decomposition of Organic Solutes in Dilute Aqueous Solutions. I. Hydrogen Abstraction from Sodium FormateM. Anbar and I. PechtCite this: J. Phys. Chem. 1964, 68, 6, 1460–1462Publication Date (Print):June 1, 1964Publication History Published online1 May 2002Publ…