Perpendicular magnetic anisotropy and perpendicular exchange bias of CoPt/FeMn bilayers fabricated by dc magnetron sputtering were investigated in this work. Magnetic anisotropy, showing strong dependence on thickness of CoPt layer, changes from perpendicular magnetic anisotropy (PMA) into in-plane magnetic anisotropy when CoPt layer is thicker than 4.5 nm. The evolution of internal stress with thickness, from tensile to compressive, has been analyzed by sin2ψ method using an equal biaxial stress model. Distinctive perpendicular exchange bias (PEB) has been successfully established due to PMA of CoPt and out-of-plane spin component of 3Q-spin-structured FeMn. FeMn thickness dependence of exchange bias field has been systematically investigated.
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