1. Institute
of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
2. Interdisciplinary
Center for Functional Particle Systems, Friedrich-Alexander University Erlangen-Nürnberg, Haberstrasse 9a, 91058 Erlangen, Germany
3. Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany
4. Institute
of Theoretical Physics, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
5. G W Gray Centre for Advanced Materials, School of Mathematics & Physical Sciences, University of Hull, Hull HU6 7RX, United Kingdom