Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 13: Topical Session: Nanomechanics of nanostructured materials and systems III - Small scale plasticity

MM 13.6: Talk

Monday, March 31, 2014, 17:30–17:45, BAR 205

Mechanical stability of quasi one-dimensional nanostructures (nanowires) — •Charlotte Ensslen, Oliver Kraft, and Reiner Mönig — Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany

Nanostructured materials are of interest for both fundamental scientific and applied research which can be ascribed to their outstanding mechanical properties, e.g. Au nanowires can exhibit high strength and ductility. In general, it can be observed that a decrease in the sample dimension results in an increase in strength known as mechanical size effect. However, data considering the mechanical properties of nanostructures with dimensions smaller than 100 nm are still rare and the corresponding deformation mechanisms and the interrelations of the microstructure, e.g. the role of inherent defects, have not been fully understood. In order to develop a profound understanding of the role of defects for the deformation mechanisms of single- and polycrystalline nanowires we make use of a helium ion microscope. It offers the possibility to design and modify nanostructures, altering the surface characteristics or creating nanopores in the nanowire prior to mechanical testing. The stress-strain curves and the deformation mechanisms of pristine and modified Au and Si nanowires are presented as recent examples. Whereas modified Si nanowires show a decreased tensile strength and a brittle failure at the defects, the mechanical behavior of modified Au nanowires seems to be independent of the defects.