No abstract

No abstract

Phone: þ7 495 939 52 48, Fax: þ7 495 939 09 98 y deceased NiX 2 @SWCNT (X ¼ Cl, Br) nanostructures were prepared by capillary filling of single-walled carbon nanotube channels with nickel halogenide melts with slow cooling down to room temperature for better crystallization. The HRTEM data indicated formation of well-ordered 1D NiBr 2 crystals, with the experimental atomic structure representing a fragment of the bulk structure. The lattice constant coincides with the corresponding distance in bulk lattice. The 1D crystal structure was modeled using DFT within the PW-GGA approach. According to the Raman, X-ray photoelectron, X-ray and optical absorption spectroscopic data and the DFT results obtained within the rigid band model, nickel halogenides display acceptor behavior with the corresponding charge transfer from the single-walled carbon nanotube walls to the NiX 2 nanocrystals.

No abstract

Anodic aluminum oxide has unique and highly attractive properties, including self-ordering of porous structure during anodization. Although anodization regimes leading to formation of highly ordered porous structures had been found experimentally, many aspects of the self-organization mechanism remain unsolved. Here, the detailed in situ small-angle X-ray diffraction study of the self-ordering in porous alumina films is reported. Structure evolution kinetics was deduced by a quantitative analysis of diffraction patterns combined with electron microscopy. The rate of pore ordering is shown to have maximal value at the initial anodization stage and rapidly decreases inversely proportional to t 0.2 . Self-organization is shown to occur via growth of domains possessing preferential in-plane orientation and "death" of other domains, similar to Ostwald ripening governed by difference in pore growth rates for domains of different orientations. The process is accompanied by pore death and splitting making a significant impact on anodic oxides utilization in any mass-transport issues. This finding opens a novel approach for growth of highly ordered porous anodic oxide films.