Perpendicular magnetization and exchange bias in epitaxialCu∕Ni∕Fe50Mn50thin films

The perpendicular magnetic anisotropy has been achieved in epitaxial $\mathrm{Cu}∕\mathrm{Ni}$ thin films deposited by magnetron sputtering. A thin ${\mathrm{Fe}}_{50}{\mathrm{Mn}}_{50}$ layer deposited on top of the Ni layer induces perpendicular exchange bias arising from the interface exchange coupling. The hysteresis loops, the ferromagnetic thickness dependence, and the angular dependence of the exchange bias in as-deposited and field-cooled $\mathrm{Cu}∕\mathrm{Ni}∕{\mathrm{Fe}}_{50}{\mathrm{Mn}}_{50}$ trilayer thin films have been investigated. This study reveals many interesting features that are much different from those of in-plane exchange biased systems. It suggests distinct magnetization reversal behavior, domain nucleation, and domain wall motion of the Ni layer in the presence of interface coupling with ${\mathrm{Fe}}_{50}{\mathrm{Mn}}_{50}$, which deserves further study.