Micromagnetics of small size patterned exchange biased Permalloy film elements (invited)

In this article, we present a study on the micromagnetics of exchange biased Permalloy films. Specifically, by combining magnetic force microscopy with micromagnetic modeling simulation, the magnetization reversal processes in exchange biased Permalloy films were studied. The bilayer films were lithographically patterned into micrometer scale rectangular elements. It is shown that the micromagnetic simulations accurately predict domain configurations during magnetization reversal of the exchange biased Permalloy film elements and provide detailed magnetization distributions and transient dynamic magnetization configurations that could not yet be obtained experimentally. The study found that, for both NiO/NiFe and FeMn/NiFe systems, the exchange bias field measured on individual patterned micrometer scale bilayer film elements can be significantly larger than that measured on the sheet film sample.