Phase diagram of magnetization reversal processes in nanorings

We investigate magnetization reversal processes of magnetic nanorings. Exploring extensive parameter sets using Monte Carlo technique combined with scaling method, we constructed magnetization switching phase diagrams for such structures. The dominant switching mechanisms are found to strongly depend on the relative spatial dimensions of the rings, i.e., height, width, and radius. Furthermore, they are shown to depend on a characteristic exchange length scale, which is determined by the competing short-range ferromagnetic and long-range dipolar interactions in these systems. Detailed simulations allow us to identify three switching mechanisms, which should be useful for building high-density storage systems.