Correlation between magnetic spin structure and the three-dimensional geometry in chemically synthesized nanoscale magnetite rings

geometry in chemically synthesized nanoscale magnetite rings M. Eltschka,1,a) M. Klaui,1,b) u. Rudiger,1 T. Kasama 2 L. Cervera-Gontard 3,a) R( E. Ounin-Borkowski,3,a) F. LUO,4 L. J. Heyderman,4 C.-J. Jia,5 L.-O. Sun,!; and C.-H . Van5 I Ftlchbereich Physik, Universitiit Konstanz, UniversitiilsstrafJe 10, 78457 Konstanz, GermallY 2Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom 3Center for Electron Nanpscopy, Technical University of Denmark, DK-2800 KOllgells Lyngby, Dellmark 4Laboratory for Microand Nallotechnology, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland 5Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry alld Applications lind PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemislly, Peking University, Beijing 100871, People 's Republic ofChinll