Materials Literature
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N,N-Dimethyl formamide (DMF) and N,N-diphenyl formamide (DPF) complexes of six lanthanide perchlorates of the composition M(DMF) 8 (ClO 4 ) 3 and M(DPF) 6 (ClO 4 ) 3 where M = La, Ce, Pr, Nd, Sm, or Y have been prepared and characterized. The infrared spectra show that the amide is bonded to the metal through oxygen.…
Chlorine ligand hyperfine structure has been observed in the EPR spectrum of the octahedral complex ion (MnCl6)4−1, in dilute solution in a single crystal of K4CdCl6 at room temperature. From the isotropic and anisotropic components of the spectrum, it is estimated that fs = 0.40%, and (fσ − fπ) = 3.9%, respectively.…
In the infrared absorption spectra of thiosemicarbazide (I), aldehyde thiosemicarbazones (II), and N-methyl derivatives of these compounds, the following assignments are proposed: ν a (N d H 2 ) absorbs in the vicinity of 3400 cm −1 ; N a H 2 vibrations are observed in the region of 1630 cm −1 ; there is a significant…
The energy transfer in amorphous polyvinyl carbazole (PVCA) has been studied by fluorescence quenching experiments using perylene, trinitrofluorenone, and hexachloro-p-xylene as guest molecules. The PVCA shows excimer fluorescence. The results are discussed in terms of exciton diffusion and competition between excimer…
Using Gärtner's equations, effect of sample thickness on the Cember potential (VD) for strong and weak absorption is discussed. It has been found that for strong absorption, as the thickness of the sample increases, VD tends to a saturation value which decreases as the front-surface recombination velocity increases. F…
From measurements of magnetization in the approach to saturation region of the hysteresis loop, a semiempirical method has been developed for determining reasonably accurate values of | K1 |/Ms and peff, the fraction of nonmagnetic volume of polycrystalline ferrimagnetic materials. The technique involves the precise m…
The mechanism of alkali ion movement in glasses during electron-probe analysis must include a dependence on the temperature of the volume irradiated. Experimental results of the composition changes of binary oxide glasses of Na2O and K2O with SiO2 during electron bombardment indicate that there is a critical temperatu…
A number of compositions A 2 3+ Ti 2 4+ O 7 and of related mixed phases were prepared and investigated. For the trivalent lanthanons from Sm to Lu, and for Y, the homogeneous A 2 Ti 2 O 7 phases were of the cubic pyrochlore type. Their lattice parameters gave a very good linear relationship when plotted against the Te…
Abstract Cellulose has been irradiated by ultraviolet light. The degradation was followed viscometrically and by weight loss measurements. The changes in the degree of Polymerization and weight of the irradiated material indicated that the degradation is random and follows first order kinetics. It is suggested that ch…
Direct measurements are reported of the dependence of the anisotropy torque on the orientation of an applied magnetic field in the $\mathrm{ac}$ and $\mathrm{bc}$ crystallographic planes of ferrimagnetic ${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{2\ensuremath{-}x}{\mathrm{O}}_{3}$ for $x=1.11$. Temperatures betwe…
Paramagnetic resonance has been observed from both single ions and isolated pairs of ${\mathrm{Gd}}^{3+}$ in Eu${\mathrm{Cl}}_{3}$ at 77\ifmmode^\circ\else\textdegree\fi{}K and 25.6 GHz. The pair spectra were analyzed in the same way as those observed previously from ${\mathrm{Gd}}^{3+}$ in La${\mathrm{Cl}}_{3}$. The…
The absorption spectrum of samples of ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ doped with Ti, V, and Cr has been measured at 4.2\ifmmode^\circ\else\textdegree\fi{}K over the frequency range 5-120 ${\mathrm{cm}}^{\ensuremath{-}1}$ in applied magnetic fields up to 55 kOe. In ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$:Ti, absorp…
Five sharp lines in the optical absorption spectrum of antiferromagnetic ${\mathrm{Cr}}_{2}$${\mathrm{O}}_{3}$ are investigated, and the assignments of four of the lines as Frenkel exciton absorptions are discussed in detail. A previous exciton assignment of these lines is shown to be inconsistent with the results of…
It has been found that various properties of liquid metals are interpretable in terms of a hard-sphere model. Since electronic screening of pair interactions in metals leads to density-dependent hard-sphere diameters, we have examined the effect that this has on the thermodynamic equations. The virial equation is show…
Historically, man's efforts to resist the effects of corrosion can be traced back several hundred years. Sir Hugh Platt (1552–1611) noted that an ‘oily substance’ prevented iron work rusting. The famous Dr. Angus Smith (1817–1884) patented a technique for coating heated metal pipes with ‘coal oil’ to resist corrosion.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure, Properties, and Cross-linking Reactions of Poly(ester acetals)Robert W. LenzCite this: Macromolecules 1969, 2, 2, 129–136Publication Date (Print):March 1, 1969Publication History Published online1 May 2002Published inissue 1 March 1969https://pubs.acs.org/doi/10.1…
An adiabatiecopper ca l? rim e ter wa s used to determine th e heats of vul ca niza ti o n of pal e c re~e natura l rubber wIth s ulfur for mIxtures varying in com pos iti o n from 0 to 32 pe rce nt added s ulfur. The s id e rea ction that produces hydroge n s ulfide was avoided by us in " reacti on te mpe ratures nea…
Using as a base the Cd0‐B 2 O 3 ‐Si0 2 photoconducting glass previously found, various systematic substitutions and additions were made to determine their influence on the photoresponse of these glasses. Complete substitution of GeO 2 for SiO 2 led to the highest photocurrents observed in these glasses and to a shift…
Minimum-weight design of a portal frame for alternative loadings is discussed. A linear programming formulation is used. The concept of Foulkes mechanism as the necessary and sufficient condition for optimum is generalized for this class of problems.
Measurement of saturation magnetization and Curie temperature were made of the solid solutions (Fe1−yMny)1.67Ge for 0≤y≤0.4. The Curie temperature decreased linearly from 485° to 326°K while the saturation magnetization, in μβ per mole, decreased from 2.65 to 2.35 for y=0.2 and then increased up to 2.66 for y=0.4. The…