Exchange bias in antiferromagnetic coupled Fe₃O₄+Cr₂O₃nanocomposites

Abstract

Exchange bias (EB) and magnetic properties of ferrimagnetic (FI) Fe3O4 and antiferromagnetic (AFM) Cr2O3 nanocomposites prepared by mechanical alloying have been investigated. A large EB field of 2.2 kOe at 10 K is observed in one of the nanocomposites, which may be related to the uncompensated and pinned AFM spins at the interface between FI and AFM phases of the nanocomposites. The EB field varies with the strength of cooling field and the content of the Cr2O3 phase, the phenomena observed are explained in terms of interfacial exchange interaction between the two phases.