18 research outputs found
Electronic structure and optical properties of concentric-shell fullerenes from electron energy-loss spectroscopy in transmission
Nucleation and growth of carbon onions synthesized by ion implantation at high temperatures
Resonant nuclear reaction analysis study of carbon phase formation during carbon ion-implantation into silver substrates
Optical transmittance spectroscopy of concentric-shell fullerene layers produced by carbon ion implantation
Optical transmittance spectroscopy of concentric-shell fullerene layers produced by carbon ion implantation
Nucleation and growth of carbon onions synthesized by ion implantation at high temperatures
Electronic structure and optical properties of concentric-shell fullerenes from electron energy-loss spectroscopy in transmission
Resonant nuclear reaction analysis study of carbon phase formation during carbon ion-implantation into silver substrates
Étude morphologique d'agrégats inclus dans des couches minces superficielles par diffusion centrale des rayons X en incidence rasante
Parmi les techniques d'analyse de surface et plus particulièrement celles faisant intervenir les rayons X, la plus récente est la diffusion centrale des rayons X en incidence rasante (GISAXS). Cette nouvelle technique non destructive, conduite auprès d'une source de rayonnement synchrotron, permet de caractériser morphologiquement des agrégats déposés sur un substrat plan ou contenus dans une couche superficielle. A l'aide de détecteurs bidimensionnels de type Imaging Plate, il est possible d'étudier la forme, la taille ainsi que la répartition spatiale des agrégats. Nous nous intéressons d'abord au cas des systèmes immiscibles carbone-métal : la technique GISAXS permet de mettre en évidence la forme allongée des agrégats métalliques inclus dans une matrice de carbone. Puis nous donnons les résultats obtenus dans le cas de multicouches granulaires (agrégats magnétiques de cobalt inclus dans une matrice d'alumine) qui montrent une structure tout à fait particulière et très ordonnée des multicouches avec un ordre à l'intérieur de chaque couche mais également de couche à couche.Among surface analysis techniques and specially those using X-rays, the most recent is the grazing incidence small-angle X-ray scattering (GISAXS). Full potentialities of this non-destructive technique are obtained when using a synchrotron source and when patterns are recorded with Imaging Plates. It is then possible to study the shape, the size and the spatial distribution of aggregates deposited on a flat substrate or embedded in a thin layer. We show the case of some carbon-metal layers when the solubility of carbon in the metal is weak. GISAXS patterns show that metallic aggregates embedded in a carbon matrix are elongated along the growth direction of the thin film. Results obtained with granular multilayers (magnetic cobalt aggregates in an alumina matrix) are also given. In this second case, it is shown that a spatial order exists not only in every layer, but also between the successive layers. It allows to show the particular and well-ordered structure of those multilayers
Carbon onions thin film formation and characterization
Spherical carbon onions (10-20 nm in size) have been
synthesized by high-fluence () 120Â keV
carbon-ion implantation in silver substrates heated at . We
report Transmission Electron Microscopy (TEM) observations obtained from these
carbon clusters. Atomic Force Microscopy images of the implanted surface
assess the formation of a high density of spherical carbon onions. The
implantation process used here can become a powerful technique to synthesize
thin films constituted of large quantities of carbon onions and thus opens new
opportunities to study their unknown properties