Dresden 2006 – scientific programme

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DS: Dünne Schichten

DS 23: Nanowires, nanoparticles and nanostructures

DS 23.4: Talk

Thursday, March 30, 2006, 16:45–17:00, GER 38

Electronic properties of nanometer-sized ion tracks embedded in tetrahedral amorphous carbon — •Anne-Katrin Nix¹, Daniel Schwen¹, Hans Krauser², Christina Trautmann³, and Hans Hofsäss¹ — ¹II. Physikalisches Institut, Universität Göttingen, Germany — ²Hochschule Harz, Wernigerode, Germany — ³Gesellschaft für Schwerionenforschung, Darmstadt, Germany

We investigated the formation of quasi one-dimensional conducting filaments in diamondlike carbon (DLC) films by swift heavy ion irradiation. Various DLC films with thicknesses of several 100 nm were grown using mass separated ion beam deposition on highly conducting Si and Fe substrates. After deposition the films were irradiated with 1 GeV ²³⁸U ions with fluences between 10⁹ and 10¹¹ ions/cm². Due to their high electronic energy loss of about 30 keV/nm the swift heavy ions graphitize the predominantly (80%) sp³-bound carbon film along their trajectories yielding conductig nanowires embedded in an insulating matrix. Using atomic force microscopy (AFM) with conducting cantilevers and applied bias voltage the presence of conducting tracks was confirmed and their conductivities were determined to be several orders of magnitude higher than of the host matrix. Temperature dependent electrical measurements were performed on the irradiated samples at 300 K - 10 K with fields up to 5 V/µm. We will discuss the results with respect to contact resistances and possible one-dimensional conduction mechanisms within the tracks.