Large scale micromagnetic simulation for the exchange interaction between a polycrystalline antiferromagnet and a ferromagnet

摘要

In recent years, the topic of exchange bias has generated a strong research interest both in the scientific and technological community, owing at least partly to its use in Giant Magnetoresistive Heads and potential use for spintronic devices. We investigate some aspects of this interaction by micromagnetically simulating our model with almost a quarter million elements which translates into a sample large enough to be correlated to experimental results. We considered the exchange coupled system of permalloy and polycrystalline NiMn. A model simulation was also undertaken substituting the biaxial antiferromagnet (AF) with an uniaxial AF, retaining all the other atomic parameters, to evaluate the effect of symmetry of the AF on loop shapes.