Magnetic composites spectroscopic studies

Wilson et al. [2] carried out a compositional and solid state nuclear magnetic resonance (NMR) spectroscopic study of humic and fulvic acid and fractions present in soil organic matter. 

SmSe and YSe form a continuous series of solid solutions. The lattice constants as a function of composition show deviations from Vegard s law, as shown in Fig. 70, Gronau [1]. The lattice constant, a = 5.90 A, is given for the deep purple mixed crystal Smo.5Yo.5Se by Welber, Jayaraman [2]. No transition into the mixed valence state is observed in the Smi xYxSe series for all values of x (at least up to x = 0.75) as concluded from color, lattice constants, and magnetic susceptibility data [1], or from Raman spectroscopic studies, Guntherodt et al. [3]. 

In general, several spectroscopic techniques have been applied to the study of NO, removal. X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) are currently used to determine the surface composition of the catalysts, with the aim to identify the cationic active sites, as well as their coordinative environment. 

The formation of complex ions is an important problem for the study of the structure and properties of molten salts. Several physicochemical measurements give evidence of the presence of complex ions in melts. The most direct methods are the spectroscopic methods which obtain absorption, vibration and nuclear magnetic resonance spectra. Also, the formation of complex ions can be demonstrated, without establishing the quantitative formula of the complexes, by the variation of various physicochemical properties with the composition. These properties are electrical conductivity, viscosity, molecular refraction, diffusion and thermodynamic properties like molar volume, compressibility, heat of mixing, thermodynamic activity, surface tension. 

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