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Magnetic nanocomposite sorbents for disposal of synthetic detergents from wastewater were synthesized. Obtained sorbents based on clay minerals (saponite, palygorskite, and spondyle clay) and magnetite were characterized by X-ray powder diffraction, Mössbauer spectroscopy, and ballistic method with Steinberg magnetometer. As a result, the average crystallite sizes of Fe 3 O 4 nanoparticles in magnetic nanocomposites were 2-10 nm. Magnetic nanocomposites had superparamagnetic properties and were classified as soft magnetic materials. Comparison of sorption properties showed that magnetic composite sorbents had efficiency of adsorption removal of anionic surfactants and polyphosphates from aqueous solution 2-8 times higher compared to native clay minerals. Spent magnetic nanocomposites were effectively removed from the aqueous solution by magnetic separation. So, the efficiency of magnetic composites application and implementing of magnetic separation in adsorption purification was confirmed.

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Using Mössbauer spectroscopy and electron paramagnetic resonance, it is shown that Fe2+ and Fe3+ compounds in the coal increase the spin concentration in the carbon nanoclusters (aromatic area) and in the intercluster space (aliphatic medium). The Fe2+ compounds preferentially support the increase of dangled bonds in carbon nanoclusters, whereas the Fe3+ ones assist the formation of free radicals in the intercluster space. By means of the electron-nuclear double resonance, it is shown that hydrogen atoms are located in the both nanoclusters and intercluster space with the higher hydrogen content in the intercluster space. The saturation of dangled bonds by hydrogen and the increase in the fraction of free radicals serve as prerequisites for methane formation. In comparison with Fe3+, the Fe2+ compounds are more effective as catalysts for methane formation.

Ternary intermetallic R5Fe6Sn18 (R = Tm, Lu) compounds have been synthesized from the elements by arc melting, annealed at 670 K and characterized by X-ray powder diffraction and energy dispersive X-ray analyses. Performed structure refinements have shown that they crystallize in the cubic Tb5Rh6Sn18 structure type (space group F m-3m, a = 13.55399(4) Å, a = 13.53243(5) Å for Tm and Lu compounds, respectively). Using 57 Fe Mössbauer spectroscopy it has been found that the magnetic state of the Fe atoms in the Tm5Fe6Sn18 and Lu5Fe6Sn18 stannides is paramagnetic. The value of the isomer shifts for Lu5Fe6Sn18 and Tm5Fe6Sn18 is positive relative to pure Fe. The 57 Fe Mössbauer spectra for Lu5Fe6Sn18 and Tm5Fe6Sn18 stannides have shown that the quadrupole splitting for the Fe position (24e) have magnitudes of 0.43 and 0.45 mm/s, respectively. The similarity of these values is consistent with a qualitative crystal structure analysis. The examined Tm5Fe6Sn18 and Lu5Fe6Sn18 compounds have been found to be characterized by metallic-like conductivity and high values of electrical resistivity (672.9 µΩ cm, 623.8 µΩ cm at 300 K for Tm and Lu, respectively).