Exchange bias effect in L10-ordered FePt and FeCo-based bilayer structure: effect of increasing applied field

Hard/soft magnetic bilayer thin films, well known for their exchange spring behaviour, are most important in the field of spintronics due to their application in magnetic recording media, permanent magnets 1, 2, magnetic micro-actuators 3, spin filtering and magnetic tunnel junctions 4.Recently, these systems have generated much interest in the field of exchange bias (EB) 5678 due to their resemblance to a conventional antiferromagnetic/ferromagnetic (AFM/ FM) layered EB system wherein cooling of the AFM/FM bilayer below Neel's temperature (T N ) in the presence of a magnetic field results in a shift of hysteresis loop along the field axis 9.In contrast to conventional EB 9,10 where usually a field cooling is essentially required, soft/hard magnetic systems exhibit a room temperature (RT) EB effect due to the interplay between exchange coupling at the interface and dipolar energies because of the magnetic state of the hard