Materials Literature
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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.
Magnetic correlations influence the energy of conduction electrons through the exchange coupling. A magnetization leads to a splitting of the band where, however, the states of the higher band are unstable against spin-flip with spin-wave production. The rather unknown ion-position dependence of the spin Hamiltonian c…
Room temperature 57Fe Mössbauer spectra were taken on atomically ordered and disordered iron-cobalt samples as a function of composition between 25 and 75 at.% cobalt. The degree of long-range order was determined in selected samples using neutron diffraction. The maximum values of the effective field (He) and isomer…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHeteropoly blues. V. Electronic spectra of one- to six-electron blues of 18-metallodiphosphate anionsElias Papaconstantinou and Michael T. PopeCite this: Inorg. Chem. 1970, 9, 3, 667–669Publication Date (Print):March 1, 1970Publication History Published online1 May 2002Publi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRole of p-phenylene groups in nematic liquid crystalsMichael J. S. Dewar and Ronald S. GoldbergCite this: J. Am. Chem. Soc. 1970, 92, 6, 1582–1586Publication Date (Print):March 1, 1970Publication History Published online1 May 2002Published inissue 1 March 1970https://doi.org…
Abstract Polymers of poly(ethylene terephthalate) (PET) always contain a certain amount of incorporated diethylene glycol (DEG), substituting the incorporated glycol. DEG is formed in a side reaction during the ester interchange of dimethyl terephthalate (DMT) with ethylene glycol or during direct esterification of te…
A preliminary account is given of sharp “rays” and related intensity structure revealed by high-resolution classical calculations of atomic scattering from an ordered monolayer. Factors related to use of structural features of the intensity maxima for investigation of atom–surface interaction fields are discussed.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPrecipitation during electromigration of ionsJoris. DemanCite this: Anal. Chem. 1970, 42, 3, 321–324Publication Date (Print):March 1, 1970Publication History Published online1 May 2002Published inissue 1 March 1970https://pubs.acs.org/doi/10.1021/ac60285a003https://doi.org/1…
From the magnetic susceptibility measurement on YCrO3 above TN=141°K, two exchange constants J1 and J2 are estimated to be J1=−8.7 cm−1 and J2=−1.0 cm−1. In DyCrO3 weak ferromagnetism is observed along the a axis, with TN=146°K. When temperature goes below 5°K, the direction begins to rotate towards the b axis. In SmC…