AVS 51st International Symposium
    Nanometer-scale Science and Technology Thursday Sessions
       Session NS2-ThM

Paper NS2-ThM10
Mechanical and Electromechanical Behaviour of Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ Nanowires and Nanowire Bundles

Thursday, November 18, 2004, 11:20 am, Room 213D

Session: Nanowires I
Presenter: A. Heidelberg, Trinity College Dublin, Ireland
Authors: A. Heidelberg, Trinity College Dublin, Ireland
J.W. Schultze, Heinrich-Heine-Universität Düsseldorf, Germany
J.G. Sheridan, Trinity College Dublin, Ireland
B. Wu, Trinity College Dublin, Ireland
J.J. Boland, Trinity College Dublin, Ireland
Correspondent: Click to Email
Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ forms quasi-1D crystals and is structurally related to the Chevrel phases @footnote 1@. It can be viewed as a condensation polymer of (Mo@sub 3@Se@sub 3@)@super -@ units. In the crystal the {(Mo@sub 3@Se@sub 3@)@super -@}@sub n@ strands are separated by Li@super +@ counterions. The crystals dissolve in polar solvents with @epsilon@ > 45 yielding conductive polyelectrolytes. From solution conductive single nanowires with a diameter of 0.6 nm and bundles of nanowires were deposited on substrate surfaces. The bundle height is typically between 10 and 100 nm and the length exceeds 5 @micron@ @footnote 2@. Mechanical measurements on Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ nanowire bundles with a height range between 25 and 200 nm have been carried out using a SPM-nanomanipulator. For the experiments nanowires were deposited out of solution across trenches on SiO@sub 2@. The trench depth was typically between 100 and 300 nm and the width between 1 and 3 @micron@. To prevent any slippage of the nanowires 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. The size of the Pt lines varied depending on the size of the wire of interest. Lateral manipulations on nanowire bundles yielded force traces. Taking into account the wire shape and dimensions as well as the AFM cantilever dimensions, the Youngs modulus, the yield strength and the maximum bending strength of the nanowires can be obtained from the force traces. The Youngs modulus for Li@super +@(Mo@sub 3@Se@sub 3@)@super -@ nanowires has been measured to be in the range of 500 to 600 GPa. The electromechanical properties of nanowire bundles under mechanical stress were also measured. @FootnoteText@ @footnote 1@ R. Chevrel, M. Sergent, J. Prigent, J. Solid State Chem 3 (1971) 515 @footnote 2@ A.Heidelberg, J. W. Schultze, C. J. Booth, E. T. Samulski, J. J. Boland, Z. Phys. Chem. 217 (2003) 573.