סמינר כימיה פיזקאלית ואנאליטית
מרצה: Erez Zemel (Kolodney group)
מיקום: חדר סמינרים פקולטי
Reactive ion-surface interactions constitute an efficient way for impact synthesis of various species and thin films. By overcoming activation barriers, usually encountered under equilibrium conditions, one may produce novel compounds, either as gas phase species or at the surface as ultra-thin films or nanoparticles. We use C60– projectile ions in the kiloelectronvolt impact kinetic energy range. The extreme high energy density achieved and sub-surface carbon density resulted in several types of novel impact interactions not observed under other conditions.
In the present work we focus on collisional interactions between C60– and soft post transition metals which do not form carbides in the bulk (In, Sn). The bombarded surface was analyzed via electron microscopy and spectroscopy methods. Surface formation of unique nanostructures shaped as core-shell hybrid nanopillars (NPs) was observed. Further exposure of the post transition metals to the C60– ion beam also resulted in emission of giant fullerenes (GFs) from the bombarded surface. NPs growth parameters, structure, and composition were characterized. Results reveal metal core and amorphous carbon rich shell nanostructures with controllable diameter, height, directionality and position. A novel NP formation mechanism based on unique growth conditions is proposed. Characterization of the properties and composition of the NPs and GFs emission conditions could reveal how carbon behave in a non-soluble system environment such as a post transition metal and set the foundations of future use of NPs based applications.