Shape deformation of embedded metal nanoparticles by swift heavy ion irradiation

an invited paper of SHIM 2008Swift heavy ions (SHI) induce high densities of electronic excitations in narrow cylindrical volumes around their path. These excitations have been used to manipulate the size and shape of noble metal nanoparticles embedded in silica matrix. Films containing noble metal nanoparticles were prepared by magnetron co-sputtering techniques. SHI irradiation of films resulted in the formation of prolate Ag nanoparticles with major axis along the ion beam direction. It has been observed that the nanoparticles smaller than the track size dissolve and other grow at their expense, while the nanoparticles larger than track size show deformation with major axis along the ion beam direction. The aspect ratio of elongated nanoparticles is found to be the function of electronic energy loss and ion fluence. Present report will focus on the role of size and volume fraction on the shape deformation of noble metal nanoparticles by electronic excitation induced by SHI irradiation. The detailed results concerning irradiation effects in silica-metal composites for dissolution, growth and shape deformation will be discussed in the framework of thermal spike model

Niveaux excités de 11B observés dans la diffusion 4He + 7Li

The (α, α) scattering cross-sections on 7Li have been measured between E = 1.36 and 3.20 MeV. The R-matrix formalism has been used for the analysis of these results together with inelastic scattering data. Parameters for levels in 11B at Ex = 9.87, 10.26, 10.33, 10.38 and 10.60 MeV have been deduced and compared to those of analog states in 11C.Les sections efficaces différentielles de la diffusion élastique 7Li(α, α) 7Li ont été mesurées entre E = 1,36 et 3,20 MeV. L'analyse cohérente de ces résultats et de ceux de la diffusion inélastique a été effectuée au moyen du formalisme de la matrice R. Les paramètres des niveaux de 11B à Ex = 9,87 ; 10,26 ; 10,33 ; 10,38 et 10,60 MeV ont été déduits et comparés à ceux des niveaux analogues de 11C

Synthesis of SiO2_{2} thin films by reactive laser ablation

French TV associations seem seeking a new way of making television, a way based on a deconstruction process. This paper explore this process working through what instituate television as a mode of producing, consuming, broadcasting, as a typology of cutural products, as a mode of social representing. It shows that deconstruction is an elaborating process based on an alter -and not anti- position