Magnetic proximity effects in antiferromagnetic composite thin films: Roles of triggering perpendicular magnetic anisotropy

Antiferromagnetic (AFM) thin films have been proposed as a promising material for manipulating perpendicular magnetic anisotropy (PMA) in ferromagnetic (FM) thin films. In this work, a series of epitaxially grown AFM/Co/Fe structures are investigated, in which the AFM layer is composed of fcc ${\mathrm{Fe}}_{50}{\mathrm{Mn}}_{50}$ and vertically expanded face-centered-tetragonal Mn films with distinct three-dimensional quadratic-type and two-dimensional layered spin structures, respectively. Our findings demonstrate that an individual AFM film in the composite AFM layer not only can enhance the long-range AFM ordering in its adjacent AFM neighbor but also can exert control over the neighbor's AFM spin structure; these modulation mechanisms subsequently induce PMA in an adjacent FM film. The research sheds light on the AFM proximity effects within the AFM composite layers and their profound influence on PMA induction in adjacent FM layers, offering essential insights for improving control over PMA with AFM layers.