Mikk Antsov
University of Tartu, Estonia
Title: Observation of shape restoration effect in core-shell nanowire structures
Biography
Biography: Mikk Antsov
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.
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