Interaction between ferromagnetic/antiferromagnetic systems across a common antiferromagnetic spacer

Many aspects of exchange bias between antiferromagnets and ferromagnets remain unclear despite substantial recent research. A principal outstanding issue is the relationship between exchange bias and enhanced coercivity in the ferromagnetic layer. Using a trilayer ferromagnet/antiferromagnet/ferromagnet structure deposited and measured under specific field conditions, we demonstrate that the micromagnetic structure in the antiferromagnet which maintains exchange bias at one interface is sufficiently randomized at the other interface that no net bias is detectable, but it does maintain enhanced coercivity.