Template based fabrication and electrical conductivity of metal doped oxide nanotubes and thin metal nanowires

• Applicant: Professor Dr. Michael Wark
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 26108942

Conductive nanotubes and nanowires are highly attractive materials for many aspects of nanoelectronics. Thus applicable nanotubes must consist of semiconducting walls, which are preferably additionally doped with metal particles enabling electron hopping transport. By employing metal salt nanofibres as templating structures we developed a sol-gel based coating route to metal oxide nanotubes containing metal nanoparticles as well in the tube interior as in the walls. Thus Pt-doped TiO2 nanotubes, precipitated from solution, exhibit aspect ratios up to 800. Since already the templating salt fibers showed electric conductivity we will now coat contacted Pt[NH3]4(HCO3)2 nanofibers on substrates either with metal alkoxides or with pre-formed metal oxide nanoparticles. The influences of electric fields on the coating and the effects of the metal oxide layer growth and the formation of grain boundaries in the nanotube walls on the conductivity of the composites will be elaborated. Their conductance will be measured as function of temperature and gate voltage in order to develop models for the electron hopping in the salt nanofibres and the composites. Further aims concern the formation of metal nanowires in the oxide nanotubes or in meso-porous oxides and the transformation of the oxide nanotubes into semiconducting non-oxide ones.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1165: Nanowires and Nanotubes: From Controlled Synthesis to Functions