Magnetic Behavior of Single Nanostructures and Their Mutual Interactions in Small Ensembles

A method is introduced that allows for the investigation of the magnetic behavior of single nanostructures in a wide range of temperatures and external magnetic fields. The technique is based on the anomalous Hall Effect utilizing nano-scaled Hall crosses. The nano-devices as well as the nanostructures are created out of sandwich films made from Pt/Co/Pt via ion milling. For the single nanostructures we identify a much too large attempt frequency which is shown to be partially caused by a temperature dependence of the magnetic anisotropy. It is shown that the magnetic behavior of and the mutual interaction in small numbers of nanostructures can be resolved. The interactions cause a strong change of the magnetic behavior of the individual particle particularly in case the system is affected by thermal energy. The latter happens even on a reasonable large scale of particle separation.