AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Monday Sessions
       Session NS2-MoM

Paper NS2-MoM4
Determination of the Mechanical and Electromechanical Properties of 1D-nanostructures

Monday, October 31, 2005, 9:20 am, Room 210

Session: Nanowires
Presenter: A. Heidelberg, Trinity College Dublin, Ireland
Authors: A. Heidelberg, Trinity College Dublin, Ireland
B. Wu, Trinity College Dublin, Ireland
J.G. Sheridan, Trinity College Dublin, Ireland
J.J. Boland, Trinity College Dublin, Ireland
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Nanowires (NWs) have attracted considerable interest as nanoscale interconnects and as the active components of both electronic and electromechanical devices. Nanomechanical and nanoelectromechanical measurements are a challenge but remain key to the development and processing of novel NW-based devices. Here, we report a general method to measure the spectrum of NW mechanical properties based on NW bending under the lateral load from an atomic force microscope (AFM) tip.@footnote 1@ For electromechanical measurements bending experiments have been carried out with simultaneous measurement of the N@aa W@s conductivity. Mechanical measurements on Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ NW bundles@footnote 2@ with a diameter range between 25 and 200 nm have been carried out using a SPM-nanomanipulator. In these experiments NWs were deposited out of solution across trenches on SiO@sub 2@. To prevent any slippage of the NWs during the manipulation, they were pinned down by E-beam induced deposition of Pt at the trench edges in a dual beam FIB/SEM system. Taking into account the wire shape and dimensions as well as the AFM cantilever dimensions, the Youngs modulus and the maximum bending strength of the NWs can be calculated from the force-displacement traces obtained by the lateral manipulations. The Youngs modulus for Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ NWs shows a strong radius dependence. It increases exponentially with decreasing NW diameter which can be attributed to shear effects between the individual NWs in the NW bundles. For NWs with a radius of 30 nm a modulus of 1.22 TPa is found. The NWs show brittle failure and the bending strength increases with decreasing wire radius. Electromechanical properties of NW bundles were also measured and compared to data obtained on metallic (Au, Cu) and semiconducting (Si) NWs. @FootnoteText@ @footnote 1@B. Wu, A. Heidelberg, J. J. Boland, Nat. Mater. (accepted)@footnote 2@A. Heidelberg et al., Z. Phys. Chem. 217 (2003) 573.