1. ITA Institute for Innovative Technologies, Köthen, branch office Halle, Wiesenring 4, D-06120 Lieskau (Halle/S.), Germany; Department of Physics, Martin-Luther-University, D-06099 Halle/S., Germany; Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany; Dyneon GmbH & Co. KG, Werk Gendorf, 84504 Burgkirchen, Germany; and Department of Physics, Visva-Bharati, Central University, Santiniketan, West Bengal 731235, India