Materials Literature
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Summary Wardite, NaAl 3 (OH) 4 (PO 4 ) 2 . 2H 2 O, has a = 7·03 Å, c = 19·04 Å; space group P 4 1 2 1 2 or P 4 3 2 1 2. Its crystal structure was solved by a three-dimensional Patterson function computed using intensity data photographically collected by the Weissenberg method, and refined by successive Fourier maps a…
Recent advances in the study of microwave ferrites and garnets have resulted in a better understanding of the relationship between magnetic properties and the fundamental crystal structure. This article presents a review of the way in which the crystal structure of microwave garnets may be designed in order to realize…
The existence of stable and metastable forms of 2ZrO 2 ·P 2 O 5 and the subsolidus phase relations in the system ZrO 2 ‐ZrP 2 O 7 were confirmed before investigation of the ternary system. The synthesis and thermal behavior of ZrW 2 O 8 were reinvestigated, and the system WO 3 ‐P 2 O 5 was examined cursorily. A ternar…
Abstract Poly‐2‐oxazolidones of high molecular weight have been synthesized from diisocy anates and diepoxides. The synthetic method was first developed for the model compound 3‐phenyl‐5‐phenoxymethyl‐2‐oxazolidone prepared from phenyl isocyanate and phenyl glycidyl ether. Conditions found most suitable for a high yie…
Abstract The effect of various soluble and insoluble surface active agents on the absorption of ammonia into a static aqueous system was studied. Saturated straight‐chain hydrocarbons with four to twenty‐two carbon atoms and polar end groups were selected as the surface active agents to be studied. Alcohol, amine, and…
A field-induced spin reorientation has been observed in the weak ferromagnet, ErCrO3, at temperatures below the Néel point, TN=133.2°K. With a magnetic field, H, along the a axis of this orthorhombic compound, the spontaneous magnetization rotates from the c axis, at H=0, to the a axis, at H=Ht. The ``transition'' fie…
Experimental values are given of the thermal conductivity and thermoelectric power of n-type silicon doped with phosphorus, antimony or arsenic, containing 4*10 19 to 6*10 25 m -3 electrons at room temperature, covering the range 4-300 degrees K. A theoretical treatment, using the variational method, suggests that the…
A series of solid solutions with the general formula La1−xCaxFe1− xMnxO3, where x is from 0.0 to 1.0, have been synthesized and their structural, magnetic and electrical properties have been studied. Polycrystalline samples were prepared by the usual ceramic method, firing at 1350° under a flow of oxygen gas to keep t…
Neutron diffraction measurements on powder and single-crystal samples of V2O3 have confirmed the existence of long-range magnetic order in the low temperature (monoclinic) phase. Paoletti and Pickart1 discovered an extra diffraction peak at low temperature which they attributed to nuclear scattering. A polarization an…
Gleotrichia echinulata was planktonic in Green Lake (Seattle, Washington) during summer, making its initial appearance between May and early July and disappearing during September. It apparently spent 8 to 10 months of the year on the bottom where colonies developed from spores deposited by the preceding year’s bloom.…
A means has been found to control the rf potential of the substrate during rf sputtering. The application of this technique to the deposition of silica films has been investigated in detail. The technique can be described as the use of an adjustable rf impedance between the substrate holder and ground electrodes, whic…
Information is given to explain why or how bromine or nitrogen contributes to phosphorus-containing flame retardants. Amide and amine nitrogen generally increase flame resitance, whereas, nitrile nitrogen can detract. Essentially, all of the phosphorus in a flame retardant is accounted for in the char or solid phase a…
It is known that trans-1,4-polybutadiene shows a crystal transformation at about 76°C. The crystal structure of the high-temperature form of trans-1,4-polybutadiene has been studied by X-ray diffraction. The chain conformation of the high-temperature form is similar to that of the low-temperature form. Above the cryst…
Recent reports indicate that the average dynamic domain size in a material undergoing a change in magnetization may be significantly smaller than the static domain size. This finer dynamic domain structure can be predicted by an application of the principle of minimum entropy production Eddycurrent dissipation and dis…
Time‐index of refraction isotherms were measured for B 2 O 3 glass starting from both a high and a low temperature in the transformation region. The equilibrium index values at each temperature, obtained from both types of approach curve, were identical. As in the case of the density values, the equilibrium refractive…
Semiconductor-to-metal-type transitions were studied by magnetic susceptibility measurements on pure single phases of Ti3O5, Ti4O7, Ti5O9, and Ti6O11. This work represents a more detailed investigation than those reported previously. From this and related studies the following model is proposed to explain the observed…
Abstract The angular dependence of scattered light, P(X) , from randomly branched homopolycondensates was calculated by using moment‐generating functions. Analytical expressions could be derived both for Gaussian sub‐chains and for sub‐chains obeying random flight statistics. For small X values (region of scattered vi…
The anodic passivation of iron in aqueous carbonate solutions, pH 11·3, at room temperature gives potentiostatic polarisation curves with two well defined current peaks. the potential of the first oxidation pea. −0·58 v., indicates that passivation is primarily due to the formation of an oxide film, probably mamly mag…
Abstract The flow behaviors of a series of polyvinylchloride (PVC) resins covering a broad range of molecular weight have been examined at several temperatures. It has been shown that the influence of temperature on viscosity depends on the temperature range. That is, the flow activation energy is not constant but can…
An empirical rule governing the chemical shifts of X-ray absorption edges has been proposed and tested.