title: Tunable electrical transport through annealed monolayers of monodisperse cobalt-platinum nanoparticles.
abstract: We synthesized monodisperse cobalt-platinum nanoparticles Co(0.14-0.22)Pt(0.86-0.78) of 9 nm in diameter by colloidal chemistry methods and deposited them by the Langmuir-Blodgett technique as highly ordered monolayers onto substrates with e-beam defined gold electrodes. Upon annealing we observe an increase of conductivity over more than 4 orders of magnitude. A first attempt of explanation of this unanticipated effect, a nanoparticle displacement, could not be confirmed for annealing temperatures below 400 °C. A second approach, a carbonization of the ligands, however, could be confirmed by Raman spectroscopy. The simple thermal treatment allows tuning essential properties of electronic devices based on nanoparticles by the manipulation of the interparticle coupling, namely the electrical conductivity, the Coulomb blockade characteristic, and the activation energy of the system.
authors.affiliation: Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Yuxue
authors.initials: Y
authors.lastname: Cai
authors.forename: Denis
authors.initials: D
authors.lastname: Wolfkühler
authors.forename: Anton
authors.initials: A
authors.lastname: Myalitsin
authors.forename: Jan
authors.initials: J
authors.lastname: Perlich
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyer
authors.forename: Christian
authors.initials: C
authors.lastname: Klinke
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D004553:Electric Conductivity; D004566:Electrodes; D006838:Hydrocarbons / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D006838:Hydrocarbons; D003035:Cobalt; D010984:Platinum