1. The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand, Laboratoire ITODYS, Université Paris 7, Denis Diderot, CNRS UMR 7086, 1 Rue Guy de la Brosse, F, 75005 Paris, France, and Institute of Physics, Karl Franzens University, Universitätsplatz 5, A-8010 Graz, Austria