The very thick corrosion layers on a nail of archaeological origin were investigated, layer by layer, by various techniques: Mossbauer spectroscopy. X-ray diffraction, thermomagnetic and chemical analysis. The following model of podzol soil corrosion layer was derived: near the nucleus, crystalline iron oxides, such as Fe3O4 and Fe2O3 predominate, and on approaching the surface of the sample the quantity of magnetite diminishes and virtually disappears, haematite is found on the surface only in fine dispersed form, while the concentrations of iron-sulphur and iron-phosphate compounds are increased. This model can be explained only by active bacteria (especially sulphate reducing) playing a role in the process of soil corrosion.

The water-based magnetite Fe3O4, maghemite gamma-Fe2O3, Gd-substituted ferrites Fe[GdxFe2 (x)] O-4, Ni-Cu alloy particles suspensions and dextran-ferrite (DF) solutions were prepared for the magnetically controlled thermochemotherapy (MCT). The temperature elevation prepared nanoparticles in AC magnetic field (0.88 MHz, 7.3 kA/m, 0.15 kW) and their toxicity were characterised. The results are in a good agreement with physical and chemical properties observed by in vitro measurements. The moment and Curie temperature of magnetic nanoparticles are obtained. The corresponding models of magnetic structure for magnetite, maghemite and Gd-doped ferrites are discussed.

The first data on biogenic nanosiderite originally discovered in oxidized Fe-quartzites from the Lebedinsk deposit of the Kursk Magnetic Anomaly (KMA) are reported. Two generations of siderite with radically different morphology and crystal-chemical and physical properties were identified. The biogenic origin is substantiated for the late generation (nanosized siderite particles). We suggest that the early ores were transformed as a result of the evolution of the atmosphere and biosphere in the area of the KMA in the Phanerozoic. Such significant differences in the properties of biogenic nanosiderite and early rhombohedral siderite may provide evidence for their different origins. The early generation of siderite was most likely formed during an abiogenic process.

The present work has been undertaken to research effects of structure, morphology, volume fraction, spatial arrangement of magnetostrictive intermetallic FeGa alloy particles dispersed in modified polyurethane matrix. Correlation of composite magnetic behavior with structure and mechanical properties has been obtained by measurements of magnetostriction, remanent magnetization anisotropy, SEM, and dynamical mechanical analysis. Anisotropic chain structures of magnetic particles within the polymer with different interparticle interactions were observed. The increase of the magnetostrictive response with tailor-made magnetic anisotropy induced by magnetic particles volume fraction has been demonstrated

Studies of the mineral substance in the weathering crust (CW) of the basalts of Vietnam have shown that these basalts might be considered as a natural laboratory for the formation of mineral bionanostructures of specific crystal morphology and thermal and magnetic properties. It is suggested that the crystallization of goethite in the cuirass and underlying bauxites of the CW of Vietnam resulted from the coagulation of colloidal particles and of hydrated iron oxide under the impact of bacterial colonies, which determined the specific features.

The study of Fe/SiO2nanocomposites magnetic properties and structure relationships was performed in dependence on Fe to SiO2relative concentration and type of precursors preparation (mechanical mixing or ultrasonic homogenization). Thermal metallization method in hot hydrogen of initial reagents [хFeOOH and (100-x)SiO2] was applied for nanocermets production. It was determined that formation of air-tight shell on the particles surface affects the nanocomposites magnetization values and their air temperature stability.

To prevent the process of aggregation and growth of α-FeOOH nanoparticles, during chemical syntheses various surface-active substances (SASs) with a concentration of 3 g/dm3 were added into the solution. The applied SASs were: cetylpyridinium chloride (CPC), sodium dodecyl sulphate (SDS), and complexone EDTA. Using various methods it was found that SAS molecules have a dual effect on the obtained nanoparticles: on one hand SAS application increases the number of small α-FeOOH nanoparticles with sizes of 2–5nm. On the other hand, SAS molecules react with surface atoms of the nanoparticles and form additional compounds.

Goethite nanopowder was prepared in the process of chemical precipitation of iron salt (FCl3) and alkali (NaOH) with addition of various surface active substances (SAS): cation-active cetylpyridinium chloride (CPC), anion-active sodium dodecyl sulphate (SDS) and complexon EDTA. The concentrations of SAS were 0.3% and 1%. It could be deduced from TEM data that these SASes unambiguously influence sizes of prepared goethite particles, compared with samples, obtained without SAS: in case of adding 1% SDS and EDTA significant crystal growth takes place. To explain this situation the study of magnetic characteristics and phase composition of obtained nanoparticles was carried out using Mossbauer spectroscopy and thermomagnetic analysis (TMA). It was suggested, that different organic Fe3+- complexes formed on goethite surface under SAS influence take part in the goethite crystallization process.

To receive monosized goethite (alpha-FeOOH) nanoparticles powders in the process of chemical precipitation of iron salt and alkali various surface active substances (SAS) with concentration of 0.3% were added to water: C12H25NaO4S (anion active), C12H38ClN (cation active) and EDTA - C10H14O8N2Na2 (complexon). It has been determined that the magnetic properties of the nanoparticles under investigation change in comparison with the nanoparticles obtained without SAS addition. In all the samples under study very interesting saturation magnetization temperature dependences have been obtained. They indicate the difference in goethite temperature phase transformations connected with various surface layers formed on the nanoparticles under SAS influence.

Amorphous shell formation on the Fe-particles surface in course of mechanochemical nanocomposite synthesis in Fe2O3+Fe, Fe2O3+Al+Fe, and Fe2O3+Ga+Fe powders mixtures have been observed by Mössbauer spectroscopy and magnetic measurements.

The comparative study of Fe2O3 4-10nm nanoparticles incorporated in arabinogalactan and polyvinyl alcohol matrixes was performed by means of magnetic measurements in wide 5-900K temperature range, Mossbauer spectroscopy and transmission electron microscopy. The processes of nanoparticles different self-organization inside various polymer matrixes were revealed. These processes lead to unusual magnetic behavior of initially superparamagnetic nanoparticles owing to interparticle interactions.

Solid phase high energy mechanochemical interaction of α-Fe2O3(hematite) and Fe in powder mixture have been studied. The formation of amorphous iron-based magnetic phase in this process was detected by means of Mossbauer spectroscopy and magnetic measurements. The amount of this phase increases with Fe addition in reduced mixture. Its thermal stability have been studied by magnetic and DCS measurements at constant α-Fe2O3 and gradually increased Fe concentrations.