Grain-boundary micromagnetism

Continuum and layer-resolved calculations are used to investigate the spin structure in the vicinity of grain boundaries. Reduced exchange in the grai n-boundary region gives rise to a quasidiscontinuity of the magnetization a nd yields a perturbation which decays exponentially inside the grains. An e ffective intergranular exchange is obtained as a micromagnetically well-def ined function of the grain-boundary exchange, and it is discussed how grain boundaries affect the hysteresis loops of nanostructures.