Observation of shape restoration effect in core-shell nanowire structures

International Conference on Smart Materials & Structures

June 15 -17, 2015 Las Vegas, USA

Mikk Antsov1,3, Boris Polyakov2, Sergei Vlassov1,3, Magnus Mets1,3, Madis Umalas1,3, Sven Oras1,3 and Rünno Lõhmus1,3

Scientific Tracks Abstracts: J Material Sci Eng

Abstract :

The combination of two different nanostructured materials into a heterostructure can lead to completely new novel properties, which for both materials separately is missing. One of the most interesting and promising structures in this field are core-shell materials, for example nanowires (NWs), where the core material (metal, oxide) is covered by a other material (metal, oxide). In this work, Ag-SiO2 core-shell NWs were fabricated using a known sol-gel method, where Ag NWs were covered with a uniform SiO2 layer. The enhanced mechanical properties were demonstrated via the cantilevered beam bending technique carried out in a scanning electron microscope. The improved fracture strength and resistance to fatigue were shown and compared to the bare Ag NWs. Under electron beam radiation a novel shape restoration effect was demonstrated and studied. To fully understand this phenomenon the core and shell materials were analysed separately. Mechanical tests were conducted on the empty SiO2 shells and on Ag NWs. The experimental conditions were simulated using the finite element method and the mechanisms behind the shape restoration and fracture resistance were proposed.

Biography :

Mikk Antsov is a second year PhD student and is currently working in the University of Tartu, Institute of Physics in the Laboratory of Nanostructured Materials. His current research involves the study of the mechanisms of nanoscale friction and the mechanical properties of different nanostructures. He has published 9 papers on these topics in reputed journals.