1. Institute of Physics IA RWTH Aachen University 52074 Aachen Germany
2. University of Liverpool Liverpool L69 3BX UK
3. Leverhulme Research Centre for Functional Materials Design University of Liverpool, Materials Innovation Factory Liverpool L69 7ZD UK
4. Peter Grünberg Institute (PGI 10) Forschungszentrum Jülich GmbH 52425 Jülich Germany