Materials Literature
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The antiferromagnetic perovskites have a simple cubic-magnetic structure with nearest-neighbor exchange interactions only. The perfect-crystal Green functions can be easily expressed in terms of tabulated integrals, so that they are particularly suitable for making quantitative comparison between theory and experiment…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCellulose Xanthic Acid. I. Studies of Model SystemsJohn Dyer and Lyle H. PhiferCite this: Macromolecules 1969, 2, 2, 111–117Publication Date (Print):March 1, 1969Publication History Published online1 May 2002Published inissue 1 March 1969https://pubs.acs.org/doi/10.1021/ma60…
Abstract Monocrystals of calcium tartrate tetrahydrate, neodymium‐doped calcium tartrate tetrahydrate, and cuprous chloride have been grown by controlled diffusion in silica gel using both metathetical and decomplexation reactions. Conditions for the optimum growth of the crystals are given and it is shown how the p H…
I. Single crystals of Alnico V and Alnico VIII alloys with 35, 40, and 42 wt.% Co and 5, 7, and 8 wt.% Ti, respectively, were investigated by x-ray analysis and electron microscopy of thin foils. It was found: (1) In Alnico V, alloy decomposition begins with the formation of randomly arranged equiaxial spherical zones…
The crystal structure of gratonite has been redetermined with the use of three-dimensional intensity data. The intensities were obtained by counter and photographic technique. Three chemical units of Pb 9 As 4 S 15 are contained in the unit cell of the symmetry C 3 v 5 – R 3 m with a hex = 17.758 ± 0.014 Å, c hex = 7.…
The numerical method of deconvolution described in part I is applied to a study of a broadening factor of the diffractometer: the receiving slit. By considering this factor the validity of this direct method of deconvolution, which can also be applied to analytical profiles and to experimental profiles, is verified. T…
It is proposed that silicate glasses be classified in terms of substructures uniquely identified with primary crystallization phases. All glasses having compositions within the ranges or areas covered by a given primary crystallization phase field should constitute a separate glass type or class. This classification i…
. Above 1405 °C dissociation is complete for all compositions and the phase relations are represented by the Ru-Ir system. At 1500 °C solid solution of Ru and Ir occurs with the addition of up to 45 mole percent Ir and up to 44 mole percent Ru, respectively.
Pure iron manganite FeMn2O4 was prepared at 1250°C and quenched. It crystallizes in the b.c. tetragonal system D4h19. Neutron diffraction measurements above the Curie temperature (120°C) show that the inversion parameter is 0.91 (nearly inverse spinel). The spontaneous magnetization at 4.2°K measured in high static an…
A new method of correction of X-ray powder diffraction line profiles by deconvolution is being developed. The convolution equation, representing the phenomenon of deformation of a true diffraction line profile, is approached with the help of a quadrature formula by a system of linear equations. The bad conditioning of…
Grain-oriented silicon iron with high permeability is prepared using aluminum-nitride needles to restrain normal grain growth. The improvements in hysteresis loss of specimens with a permeability of 1920 are about 0.120 W/kg at 15 kG and 0.160 W/kg at 17 kG as compared to the commerical product with a permeability of…
The possible existence of antiferromagnetism in Ti2O3 has important theoretical implications associated with the explanation of the metal-to-semiconductor transition in this material. A previous neutron-diffraction study, using unpolarized neutrons, indicated that Ti2O3 was antiferromagnetic with the α-Fe2O3 structure…
Abstract Oriented X‐ray spacings for vermiculite and montmorillonite were obtained as the sample temperature was changed at a constant rate. Temperatures at which an abrupt change in (001) spacing took place indicated the relative ease of expansion or contraction for a series of interlayer ions. From such temperatures…
The stress required to operate dislocation sources within a grain, at a grain boundary, and at surfaces is found to be larger than the intrinsic stresses observed in polycrystalline films. It is therefore unlikely that a dislocation flow mechanism can relieve stresses in films. Grain boundary sliding and diffusional c…
SUMMARY– We studied oxidation of a freeze‐dried model system consisting of methyl linoleate and gelatin by incubating the model system in air at 50°C for up to 10 days in the dry state or at controlled relative humidities. Incubation for 5‐10 days caused a drop in the viscosity of gelatin solutions, an increase in the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyisonitriles. III. Synthesis and Racemization of Optically Active Poly(α-phenylethylisonitrile)Frank Millich and G. Keith BakerCite this: Macromolecules 1969, 2, 2, 122–128Publication Date (Print):March 1, 1969Publication History Published online1 May 2002Published inissu…
The construction and evaluation of an efficient and convenient reflection type polarizer, using three gold mirrors, which is useful in the 500-5000-A wavelength region is described. The polarizer is evaluated both by direct measurement of its polarization and by calculation from the measured optical constants of gold.…
There is a range of compositions and temperatures below the monotectic where the equilibrium solid cannot form directly from an undercooled single‐phase liquid. Thermodynamics requires either a prior liquid‐liquid Phase separation or a simultaneous formation of the second liquid if the solid is to form. The implicatio…
The heat capacity of a solid polymer is governed by the manner in which the internal energy is distributed over the various degrees of freedom. If the internal energy manifests itself in harmonic oscillatory motions, the heat capacity is the sum of contributions of the normal modes of motion. In practice, full frequen…
The ductility of Type 304L and Type 310 stainless steel as measured by tensile elongation can be reduced substantially when high contents of hydrogen are absorbed. Cathodic charging of thin stainless steel foils severely reduced the foils' ductility and tensile strength. Only a very thin surface layer was damaged by c…