Browsing by Author "Ryasnyansky, AI"

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    Application of ion implantation for synthesis of copper nanoparticles in a zinc oxide matrix for obtaining new nonlinear optical materials
    Stepanov, AL; Khaibullin, RI; Can, N; Ganeev, RA; Ryasnyansky, AI; Buchal, C; Uysal, S
    We have obtained a layered composite material by implantation of single crystal zinc oxide (ZnO) substrates with 160-keV Cu+ ions to a dose of 10(16) or 10(17) cm(-2). The composite was studied by linear optical absorption spectroscopy; the nonlinear optical characteristics were determined by means of Z-scanning at a laser radiation wavelength of 532 nm. The appearance of the optical plasmon resonance bands in the spectra indicated that ion implantation to the higher dose provides for the formation of copper nanoparticles in a subsurface layer of ZnO. The new nonlinear optical material comprising metal nanoparticles in a ZnO matrix exhibits the phenomenon of self-defocusing and possesses a high nonlinear absorption coefficient (beta = 2.07 x 10(-3) cm/W). (C) 2004 MAIK Nauka / Interperiodica.
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    Optical properties and luminescence of metallic nanoclusters in ZnO:Cu
    Karali, T; Can, N; Valberg, L; Stepanov, AL; Townsend, PD; Buchal, C; Ganeev, RA; Ryasnyansky, AI; Belik, HG; Jessett, ML; Ong, C
    Copper nanoparticles have been formed in a zinc oxide (ZnO) substrate by Cu implantation at 160 keV. The implant layer shows amorphised behaviour as monitored by the RBS data and optical absorption indicates the surface plasmon resonance peak characteristic of copper nanoparticles. There is nonlinear optical absorption from the Cu nanoparticles. There are numerous changes in the luminescence responses which include a variety of green and yellow emission bands. During excitation there were changes in the cathodoluminescence intensity and lifetime influenced by the surface events, including some unusual features, which may be considered in terms of interactions with surface water and ice. Radioluminescence signals oscillate between the normal emission bands and the wide red line emission from free Zn. Overall ZnO is, therefore, an unexpectedly interesting host for dispersed Cu nanoparticles, not least because the optical features may be compatible with the semiconductor aspects of ZnO. (c) 2005 Elsevier B.V. All rights reserved.