Synthesis and Modification of One-Dimensional Nanostructures Using Ion Beams

ChEMS Seminar

Location: CS 174

Abstract:
Amorphous carbon thin films can be grown via the deposition of low energy carbon ions. The characteristic energy dependence of the sp3-fraction shows a maximum of 80 % around 100 eV; thus, one calls such films tetrahedral bonded amorphous carbon (ta-C) and they exhibit diamond-like properties. Such insulating films were irradiated with swift heavy ions (e.g. 1 GeV 238U) causing a transformation of the sp3-material to sp2-bonded graphitic carbon along the ion path. The electrical properties of these nanometer-sized ion tracks will be presented and the conduction mechanism discussed.

The second part of the talk will describe the growth of semiconductor nanowires using the VLS-mechanism. The obtained nanowires have been doped via ion implantation. The changes of the structural, optical, electrical and magnetic properties of the ZnO and ZnS nanowires will be presented and discussed as a function of implanted species and annealing procedures.