Frustrated exchange interactions at the interface of antiferromagnetic films with ferromagnetic substrates: Mn/Fe(100)

Publisher Website
Google Scholar
Abstract
Detailed investigations of the frustration of the magnetic exchange interactions at the interface between an antiferromagnetic monolayer of Mn and a body-centered-cubic Fe(100) substrate have been performed via self-consistent spin-polarized tight-binding linear-muffin-tin-orbital calculations and the calculation of the exchange pair interactions via a real-space Green's-function technique. We find that while the Mn moments in the monolayer are strongly enhanced compared to those in bulk Mn, the moments in the top layer of the substrate are reduced by as much as 40% due to the competition between the antiferromagnetic nearest-neighbor Mn-Fe and ferromagnetic Fe-Fe interactions. The strongest frustration effects arise from the strong ferromagnetic coupling between the Mn atoms in the overlayer and the Fe atoms in the second layer of the substrate which tends to induce an antiferromagnetic component in the magnetic polarization of the top layers of the substrate. The possibility to reduce the frustration by the formation of a noncollinear magnetic structure has been investigated.