The structure dependence of exchange bias in ferromagnetic/antiferromagnetic bilayers

The structure dependence of exchange bias inferromagnetic/antiferromagnetic (FM/AF) bilayers has beeninvestigated in detail by extending Slonczewski's `proximitymagnetism' idea. Here three important parameters are discussed forFM/AF bilayers, i.e. interfacial bilinear exchange coupling $J_{1}$, interfacial biquadratic (spin-flop) exchange coupling $J_{2}$ and antiferromagnetic layer thickness $t_{rm AF}$. The results show thatboth the occurrence and the variety of the exchange bias stronglydepend on the above parameters. More importantly, the smallspin-flop exchange coupling may result in an exchange bias withoutthe interfacial bilinear exchange coupling. However, in general, thespin-flop exchange coupling cannot result in the exchange bias. Thecorresponding critical parameters in which the exchange bias willoccur or approach saturation are also presented.