We demonstrate that the switching field distribution (SFD) in arrays of 50 nm to $5\mu \mathrm{m}$ $\mathrm{Co}/\mathrm{Pd}$ elements, with perpendicular anisotropy, can be explained by a distribution of intrinsic anisotropy rather than any fabrication related effects. Further, simulations of coercivity and SFD versus element size allow the distribution of intrinsic anisotropy to be quantified in highly exchanged coupled thin films where the reversal mechanism is one of nucleation followed by rapid domain wall motion.

• Received 26 September 2005

DOI:https://doi.org/10.1103/PhysRevLett.96.257204