Variation of thin film edge magnetic properties with patterning process conditions in Ni₈₀Fe₂₀ stripes

The authors report the effect of etch depth on the magnetic properties of thin film edges in magnetic nanostructures. In transversely magnetized stripes of 20-nm -thick Ni80 Fe20, they use ferromagnetic resonance spectroscopy to measure the edge saturation field and effective out-of-plane stiffness field of the trapped-spin-wave edge mode as a function of ion etch depth. With increasing etching depth, the edge surface angle changes from 47° to 80°, and the field required to saturate the edge magnetization perpendicular to the stripe axis nearly doubles. This trend is largely confirmed by micromagnetic modeling of the edge geometry. © 2007 American Institute of Physics.