Magnetoresistance and interlayer exchange coupling between magnetic layers in Fe-Mn/Ni-Fe-Co/Cu/Ni-Fe-Co multilayers

Magnetoresistance effects and interlayer exchange coupling between magnetic layers have been investigated in [Hf/Fe–Mn/Ni–Fe–Co/Cu/Ni–Fe–Co/Hf] multilayers by varying the thicknesses of the Ni–Fe–Co, Fe–Mn, and Cu layers. When the Fe–Mn layer is thicker than 5.0 nm, it applies a strong exchange-bias field to the neighboring Ni–Fe–Co layer. The multilayers show high magnetoresistance ratios at Cu-layer thicknesses between 2.0 and 3.0 nm, because the interlayer exchange coupling is weak. The interlayer exchange coupling between the two Ni–Fe–Co layers is always ferromagnetic at Cu-layer thicknesses between 0.5 and 5.0 nm.