Field cooling induced perpendicular exchange bias in FeMn/(FeNi/FeMn)_n multilayers

摘要

Based on two-dimensional magnetization vector measurements, it is confirmed that perpendicular exchange bias can be established in conventional ferromagnetic/antiferromagnetic multilayers when the samples are field-cooled along the surface normal direction. Here we report on the experimental observations from a systematic study of the perpendicular exchange bias in FeMn/(FeNi/FeMn)_(15) multilayers and the comparison with corresponding longitudinal field cooling results. For the two field cooling geometries, both the exchange field and the coercive field exhibit similar constituent layer thickness and temperature dependences when measuring along the cooling field direction. These observations indicate the same interfacial nature of the induced anisotropy for both perpendicular and longitudinal exchange biases. The establishment of perpendicular exchange bias and anisotropy through field cooling can have potential applications in perpendicular magnetic recording media development.