In this paper we investigated the structure of the magnetic fluid based on Fe3O4 nanoparticles. Magnetic fluid based on Fe3O4 nanoparticles is used for cancer treatment, targeted drug delivery, hyperthermia, as a contrast agent in surgery, as a barrier to blood flow and others. Magnetic fluid based on Fe3O4 nanoparticles was synthesized by chemical condensation of magnetite nanoparticles. Characteristics of magnetic fluid (oxidation of iron nanoparticles size, density) were investigated using X-ray absorption spectroscopy. The changes of the antitumor effect of the magnetic fluid is associated with an increase of the particle size of the iron oxide that has a significant impact on their penetration in a tumor tissue.

Keywords: magnetic fluid, magnetite, nanoparticles, Fe3O4, oxidation state, density, antitumor activity

In this work, the nanoparticles were investigated biogenic metals iron, fine and coarse copper nanoparticles, the nanoparticles of zinc test samples showed pronounced antitumor activity in the body tumor-bearing rats. Nanoparticles were introduced into the body of rats as a solution in sodium chloride .On laboratory X-ray absorption spectrometer R-XAS Looper were measured X-ray absorption spectra (XANES) of reference samples of iron, copper, zinc foil, iron oxide, copper, zinc and investigated nanoparticles. Based on the data, it was concluded that their structure, charge state and redox pure powders and sodium chloride.

Keywords: magnetic fluid, magnetite, nanoparticles, Fe3O4, oxidation state, density, antitumor activity

Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state.  Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.

Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT

In the present work we report on the study of local atomic and electronic structure of gold nanoparticles funnctionalised by thiol and amine containing long-chain ligands. The study of nanoscale atomic structure is performed by means of X-ray absorption spectroscopy (XANES: X-ray Absorption Near-Edge Structure) and computer simulation. In consequence of the experimantally obtained data analysis and computer simulation it was obtained that strong bonding takes place when 11-mercaptoundecanoic acid is bound to the gold nanoparticles surface, forming a chemical bond Au-S 0.25 nm in length. Weaker bonding is observed when forming bond between dodecylamine and gold nanoparticles surface atom resulting in Au-N bond 0.23 nm in length. Supplementary XANES spectra analysis by means of density functional theory reveals the nature of formation of the investigated nanoscale structure.

Keywords: nanoscale structure of matter, X-ray absorption spectroscopy, XANES, density functional theory, nanoparticles functionalisation

Combined method which allows analyzing parameters of the nanoscale atomic and electronic structure of materials relying on three different methods (x-ray absorption spectroscopy (XAFS), x-ray diffraction (XRD) and Raman spectroscopy) was developed. The method was applied for the study of nickel oxide nanoparticles, which serve as an efficient catalyst for the artificial photosynthesis process. 

Keywords: solar energy, artificial photosynthesis, NiO, Raman, x-ray diffraction, XAFS