Exchange bias of ferromagnetic/antiferromagnetic in FePt/FeRh bilayers

A systematic investigation of structural and magnetic properties of FePt/FeRh bilayers has been carried out. The transition temperature of single FeRh layer is higher than that of FePt/FeRh bilayer. A sharp decrease in coercivity is observed at transition temperature for FePt/FeRh bilayer. The thickness FePt dependence of exchange bias field and unidirectional anisotropy constant are discussed. Of interest is the exchange bias effect that appears in FePt/FeRh bilayer and the unidirectional anisotropy constant, which is very large (up to 0.8 erg/cm(2)), suggesting that this system can be applied for spin-valve sensors and heat assisted magnetic recording medium. It may also provide some useful information for better understanding of the mechanism of exchange bias. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3062813]