The investigation provides the complex approach for optical properties study of the cobalt octaephylporphyrin. The complex shows the magnetic moment of the central ions. The strength and sign of anisotropy and optical transparency within the visible range can be changed by variation of an environment of the central metal atom (the ligand field) or its replacement. As a result, these materials can be used as stable qubits and nanoelements for spintronics and quantum computing. It is well-known that devices for spintronics and quantum computing require materials with femtosecond time resolution. The insights into the relations between geometry structure and optical and magnetic properties allow to design the tailor-made materials. In this work, we have investigated the optical properties of the cobalt octaephylporphyrin. We have calculated the theoretical spectra of the extinction coefficient, refraction index, and absorption index. These spectra provide us the additional information about optical transitions within the visible range. The design of the stable nanoelements with femtosecond time resolution is hardly-probable without understanding the nature of processes.
Keywords: Molecular magnets, cobalt octaethylporphyrines, optical properties, dielectric function, femtosecond time resolution
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
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