The Exchange Bias of a Permalloy and Ordered Epitaxial IrMn Thin Film Prepared From the Growth of Ultrathin [Ir/Mn] Multilayer

The influence of Ir
_1-x
Mn
_x
composition and post-annealing on structure and exchange bias of epitaxial Ir
_1-x
Mn
_x
(~10 nm)/Ni
₈₀
Fe
₂₀
(7 nm) films were studied. The Ir
_1-x
Mn
_x
layer was prepared by MBE growth of [Mn(0.4 nm <; X nm <; 0.7 nm)/Ir(0.2 nm)]
_N
multilayer films. The optimal H
_ex
increases to ~190 Oe after annealing at 533 K for 3 h. X-ray diffraction indicates that the strength of exchange bias is increased with the order parameter of Ir
_1-x
Mn
_x
alloy.