Correlation of geometrical and electronic properties in metallic nanowires

• Applicant: Professor Dr. Herbert Pfnür
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2004 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5428992

Crystalline metallic nanowires (Ag, Pb) with lateral dimensions below 10 nm down to atomic size, grown epitaxially on silicon substrates, will be studied with respect to correlations of electrical transport and the morpholgy of the wires and their interfaces. The experiments will be carried out using a combined high resolution SEM-STM system, which will be used to produce, characterize, and manipulate metallic nanowires and their surroundings down to the atomic scale. The conductance of the wires and its local variation will be measured by means of titanium silicide contact pads on the substrate and the STM tip as mobile voltage sensor so that the properties of single wires can be studied. By systematic variations of the substrate surface structure (step density, reconstruction via adsorbates) and the growth parameters (deposition rate, temperature, adsorbates) the influence of the wire interface structure and morphology on electrical transport properties will be elucidated. The wire geometry will be manipulated in order to create bottle necks by means of the STM tip and electromigration effects. The effects of single defects like grain boundaries, steps on the vacuum or substrate interface, and adsorbates on electron scattering will be accessed and quantified.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1165: Nanowires and Nanotubes: From Controlled Synthesis to Functions
• Participating Person: Professor Dr. Christoph Tegenkamp