Magnetization Reversal In Ferromagnetic Wires Patterned With Antiferromagnetic Gratings

The magnetic reversal behavior is examined for exchange-biased ferromagnetic/antiferromagnetic nanostructures consisting of an array of 10nm thick Ni80Fe20 stripes with width 200 nm and periodicity 400 nm, underneath an orthogonal array of 10nm thick IrMn stripes with width ranging from 200 nm to 500nm and periodicity from 400nm to 1 mu m. The Ni80Fe20 stripes show a hysteresis loop with one step when the IrMn width and spacing are small. However, upon increasing the IrMn width and spacing, the hysteresis loops showed two steps as the pinned and unpinned sections of the Ni80Fe20 stripes switch at different fields. Micromagnetic modeling reveals the influence of geometry on the reversal behavior. Published by AIP Publishing.