Exchange bias study of CoFeB/IrMn antidot and nanodot arrays fabricated by nanosphere lithography

Abstract

Exchange bias effect in nanostructures are widely investigated for applications in nanometric spintronic sensors. In this work, nanosphere lithography was adopted to pattern CoFeB/IrMn antidot and nanodot arrays. The exchange bias and coercivity of the nanostructures and continuous films exhibit similar exponential dependence on CoFeB layer thickness. High temperature annealing results in decreased exchange bias and coercivity. This work provides physical insights on magnetization reversal response in nanosized spintronic devices.