Off-axis electron holography of exchange-biased CoFe/FeMn patterned nanostructures

Off-axis electron holography and micromagnetic simulations have been used t o investigate magnetization reversal mechanisms and remanent states in exch ange-biased submicron Co84Fe16/Fe54Mn46 patterned elements. Domain structur es within the elements were characterized despite the narrow thickness (sim ilar to3 nm) of the ferromagnetic layer relative to the total element thick ness (similar to 42 nm). Individual elements were able to support different remanent states and their magnetic microstructure was sensitive to their s ize. The simulations confirmed that the coercivities of the elements and th eir domain structures were highly sensitive to the strength and orientation of the pinning field. A good fit to the experimental data was provided by using an interface exchange field that had a fixed amplitude and direction in the simulations, and small disagreements were attributed to structural i mperfections. These differences emphasize the value of an experimental tech nique such as electron holography for probing local micromagnetic structure in individual nanostructured elements. (C) 2001 American Institute of Phys ics.