Contribution of Local Incoherency on Gilbert-Damping

Micromagnetic simulations are performed to study the difference between fully discretized finite element simulations and macro spin simulations, where each grain is described with a uniform magnetization. Two exchange coupled grains with an edge length of 10 nm are used as test system. The magnetization of one grain is fixed with a large anisotropy. The switching time of the free grain shows that the difference between macro spin calculations and finite element simulations increases with larger intergrain exchange and smaller Gilbert damping constant. The deviation can be compensated by increasing the Gilbert-damping