Distribution of blocking temperature in exchange-coupled Fe3O4–CrMnPt system

The distribution of local blocking temperatures (TBi) in an exchange-coupled half-metallic-Fe3O4–antiferromagnetic-Cr45.5Mn45.5Pt9 system (in atomic %) was investigated, with the aim of confirming thermal stability of unidirectional anisotropy induced in Fe3O4 film, which has hard magnetic properties. The distribution of TBi was mostly at or around 265°C. This distribution in the Fe3O4–CrMnPt system was equivalent or superior to that found in a previously studied soft magnetic-Ni81Fe19–antiferromagnetic-Pt50Mn50 system, where PtMn had been used in a giant magnetoresistance device as the standard antiferromagnetic material for the exchange-biased layer. These results make it reasonable to conclude that the exchange coupled Fe3O4–CrMnPt system has excellent thermal stability.