1. KU Leuven, Instituut voor Kern- en Stralingsfysica, 3001 Leuven, Belgium
2. Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2686-953 Sacavém, Portugal
3. IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Universidade do Porto, 4169-007 Porto, Portugal
4. Laboratory of Solid-State Physics and Magnetism, KU Leuven, 3001 Leuven, Belgium
5. School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
6. Centro de Física Nuclear, Universidade de Lisboa, Lisboa 1649-003, Portugal