Exchange bias in CrN/Co nanocomposites consisting of CrN-coated Co nanocapsules and CrN nanoparticles

Nanocomposites consisting of ferromagnetic (FM) CrN-coated Co nanocapsules and antiferromagnetic (AFM) CrN nanoparticles are synthesized by the arc-discharge technique. Exchange bias (EB) and magnetic properties of the CrN/Co nanocomposites have been investigated. The shift of the hysteresis loop is 630 Oe at 5 K, which may be related to uncompensated and pinned AFM spins on the interface between the FM and AFM phases in the nanocomposites. The EB field varies with the strength of cooling magnetic field, due to the competition between the Zeeman energy and the interfacial exchange interaction. The order of magnitude of the unidirectional surface energy density is consistent with those reported for AFM oxides.