Implementation of Two-Dimensional Polycrystalline Grains in Object Oriented Micromagnetic Framework

Magnetic components in virtually all technological applications are polycrystalline due to cost constraints. Various magnetic components have been modeled with micromagnetics, largely as a single crystal with little or no magneto-crystalline anisotropy, The assumption is that when averaged over the entirety of the simulated dimensions, orientational dependence of anisotropy from randomly oriented grains will cancel out. This assumption has been valid for magnets of micron and sub-micron dimension for a long time. However, for smaller parts in the 100 nm range, it has been shown experimentally that the exact nature of grain orientation and distribution plays a crucial role in magnetization reversal behavior Refs. In response to the growing need to model the effect of grains on switching dynamics, we have expanded OOMMF's capability to model 2D through grains derived from Voronoi diagrams.