Abstract
The exchange bias field (Hex) of IrMn/CoFe deposited on a large-area nanoporous anodized alumina (AAO) is tailored by varying the pore density (D) and the network width (w) of AAO. The Hex increases with increasing D and reaches its maximum at D=5.6× 10 10 cm -2 and w∼28 nm. The enhancement in Hex, twice larger than that of the continuous film, is attributed to the reduction in antiferromagnetic (AFM) and ferromagnetic (FM) domain sizes. The suppression of Hex is observed for further increase in D, which may result from the excessive misalignment of AFM and FM spins and weakened AFM anisotropy. © 2009 American Institute of Physics.