We use ''edge mode'' ferromagnetic resonance (FMR) to probe the magentic properties of oxidized Ni80Fe20 (Py) nanostripe edges. The oxidation is carried out using either oxygen plasma or thermal annealing in an oxygen ambient. We find that for both treatments the edge saturation field decreases systematically with increasing oxidation due to reduced magnetization near the edges. However, the change of effective out-of-plane anisotropy field shows opposite trends for these two oxidation methods. Micromagnetic simulations suggest that thermally annealed samples may have an additional reduction in the bulk magnetization, possibly due to a compositional change in Py stripes. The two distinct oxidation profiles also result in different changes in resonance linewidth from which we find little damping change for plasma treatment but an enhanced effective damping for thermal annealing.
Citation: Journal of Applied Physics
Pub Type: Journals
magnetization dynamics, edge oxidation