The effects of edge defects on the switching characteristics of bit patterned media

We present the results of micromagnetic studies on realistic patterning defects in perpendicularly oriented magnetic thin films. Both undercut and line edge roughness are investigated systematically with simulations using simple test structures to see the effect of the side wall angle, the roughness amplitude on a nanostructureiquests switching field, and the roughness period on mathematically tractable figures. We then run simulations of hysteresis loops of actual 200 nm diameter nanostructures using AFM images to define the structure boundary and compare the results to MFM images of DC demagnetized dots.