Materials Literature
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Abstract In order to confirm the assignment of the Raman active internal modes of K 2 SO 4 and structurally related crystals, the Raman spectra of oriented cyrstals have been recorded. Using the relative integrated intensities of the bands as data, the transferability of the Raman tensors of the free SO ion to the cry…
Abstract The adsorption of CO 2 at low temperature (~ -70°C) on thin films of homoionic smectites was studied by X-ray diffraction and by i.r. absorption. An increase in the d 001 spacings of these clay films upon adsorption of CO 2 was observed. In addition, a dichroic effect was readily discernible by comparing the…
The magnetic properties of Heusler alloys of approximate composition Cu2MnAl have been studied by Lorentz microscopy. as a function of composition, heat treatment and plastic deformation. Magnetic domain walls have been observed to be pinned at antiphase boundaries. The strength of pinning varies with composition and…
Abstract Tubular halloysite from Wagon Wheel Gap, Colorado and spheroidal halloysite from Redwood County, Minnesota were examined by transmission electron microscopy. Clay samples were prepared by the following techniques: drop-mounted suspension on carbon support films; thin sections of clay in Araldite epoxy resin;…
Crystallographic and magnetic properties were studied in the disordered γ-phase Mn 1- x Ir x (0.05< x <0.35) alloys. In Mn rich alloys, tetragonal distortion with axial ratio c / a >1 occurs at a temperature below their Néel temperature, T N . The tetragonal distortion temperature, T d in the antiferromagnetic ordered…
The phases in the kaolinite‐mullite reaction sequence were reexamined by ir absorption spectrophotometry. Particular attention was paid to the controversial intermediate Al‐containing phases. Amorphous materials were leached from fired kaolinite samples with NaOH to help identify crystalline phases. Metakaolinite part…
The x-ray photoelectron spectra of tetraphenylporphin, phthalocyanine and their copper complexes were measured. The copper complexes show a single nitrogen 1s photoline, whereas the metal free bases give rise to a doublet nitrogen 1s photoline. The central pyrrole and aza nitrogens in the metal free bases could be ide…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComputation of structures of homologous proteins. .alpha.-Lactalbumin from lysozymeP. K. Warme, F. A. Momany, S. V. Rumball, R. W. Tuttle, and H. A. ScheragaCite this: Biochemistry 1974, 13, 4, 768–782Publication Date (Print):February 1, 1974Publication History Published onl…
The scanning limitations of rms-responding liquid-crystal devices as influenced by device characteristics, the type of matrix addressing scheme, and waveform tolerances are quantified in this paper. An rms selection scheme that yields a greater number of scanned lines than a 3:1 selection scheme is presented and analy…
Fine single‐domain and polydomain particles of tetragonal ZrO 2 were prepared by hydrothermal and heat treatment of ZrO 2 · n H 2 O. The particles were characterized by X‐ray diffraction, electron microscopy, NMR, mass spectrometry, and ir spectroscopy. The main impurity in the samples was 1 to 2 wt% OH − ions, most o…
A simple theoretical calculation is given in which the energy distribution of low-energy secondary electrons emitted from metals is derived. The main feature of the calculation is an energy-dependent electron mean free path. The theory predicts that the peak of the energy distribution occurs at a value of the secondar…
RELATIVE EFFICIENCY OF CARBONATE DISSOLUTION AND PRECIPITATION DURING DIAGENESIS: A PROGRESS REPORT ON THE ROLE OF SOLUTION CHEMISTRY
The mechanical behavior of uranium and its alloys is reviewed with special emphasis on plastic flow behavior of polycrystalline materials. The strength of uranium is influenced by crystal structure as well as by point, planar, and volume defects; wit these factors in mind, texture hardening, strain hardening, solute h…
A neutron diffraction study has been made on the magnetic structure of single crystalline Mn 3 O 4 from liquid helium temperature to the Neel point, 41K, and the nuclear structure at room temperature has been refined.
Films of rubidium were deposited on quartz substrates by evaporation at pressures of less than 10−10 Torr. The work function of the films was determined photoelectrically, and at 140 K was found to be (2.261 ± 0.015) eV. Warming the film to room temperature caused an irreversible reduction of about an order of magnitu…
Thermally and IR-stimulated luminescence and conductivity of Cu and Li doped ZnO single crystals have been investigated in the temperature range from 5 to 100 K. It is shown that the stimulation of the green emission is related to the generation of free charge carriers, while the yellow emission is produced mainly by…
The orientation factor, K, of elastic dislocation energy is calculated for dislocations in KDP (space group I42d) with Burgers vectors b = 〈100〉, [001], 〈110〉, 〈011〉, and 1/2〈111〉. As a result of elastic anisotropy, for dislocations with b = 〈110〉, K has an absolute maximum in pure screw orientation. The preferred lin…
The photoelectronic properties of virgin CdS platelets, sublimed and cooled in an N2–H2S atmosphere, were altered by heat treatment in ultra-high vacuum. The untreated crystals showed a strongly structured spectral distribution of the photoconductivity (SDP) at liquid nitrogen temperature (LNT), having maxima (Class I…
The initial stages of ordering in Ni3Mo and Ni4Mo have been investigated by transmission electron microscopy and diffraction. The development of long-range order in Ni3Mo is associated with decomposition into the two metastable phases Ni2Mo and Ni4Mo, which are eventually replaced by the equilibrium Ni3Mo at a later s…
Segregation from solutions and melts is compared theoretically. It is shown from thermodynamic arguments that equilibrium solution segregation is more effective. Segregation coefficients k0 are calculated for aqueous alkali halide systems, based upon theoretical heat of dissolution values (solid solution) and solubili…