Relation between microstructures and magnetic properties upon annealing in Fe_(50)Mn_(50)/Ni_(80)Fe_(20) films

摘要

The annealing-temperature-dependent change in the exchange bias and coercivity is investigated in Fe_(50)Mn_(50)/Ni_(80)Fe_(20) films. It is interesting to note that, as the annealing temperature increases, the exchange bias first decreases, and then increases, and finally decreases for the case of annealing at the higher temperature. The coercivity will increase upon annealing at moderate temperature, but decrease upon higher-temperature annealing. We can qualitatively interpret the change of the magnetic properties with annealing temperature in connection to the microstructures by x-ray scattering technologies. The results show that both the large exchange bias field and low coercivity of Fe_(50)Mn_(50)/Ni_(80)Fe_(20) films are dependent of not only the interfacial roughness but also the antiferromagnetic structure.