a
Center for Individual Nanoparticle Functionality, Department of Physics, Building 312, Technical University of Denmark (DTU), DK-2800 Lyngby, Denmark
E-mail: ibchork@fysik.dtu.dk
b
Current address: Center for Electrochemical Sciences Ruhr Universitaet Bochum, Universitaetsstr. 150 NC 4/73, 44780 Bochum, Germany
c
Center for Atomic-Scale Materials Design, Department of Physics, Building 307, Technical University of Denmark (DTU), DK-2800 Lyngby, Denmark