The present work is devoted to study of atomic and electronic structure of nitrospiropyran molecules deposited on a Bi (111) substrate before and after irradiation by UV light and X-rays. The study was done using the density functional theory (DFT) and a theoretical analysis of the X-ray absorption fine structure (XAFS) spectroscopy. As a result of the calculations the low-energy structure for nitrospiropyran molecules on a Bi (111) substrate was obtained.

Keywords: local atomic and electronic structure, X-ray absorption spectroscopy, photoisomerization, density functional theory

The present work is devoted to the local atomic and electronic structure of dimetacyano (DMC) molecules deposited on a Bi (111) substrate before and after irradiation by X-rays and UV light using density functional theory (DFT) and a theoretical analysis of the X-ray absorption near edge structure (XANES) spectroscopy. As a result of the calculations the low-energy structure for DMC azobenzene molecules on a Bi (111) substrate was obtained.

Keywords: local atomic and electronic structure, X-ray absorption spectroscopy, photoisomerization, density functional theory

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 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