Effects of Interfacial Exchange Interaction on the Antiferromagnet-Induced Perpendicular Magnetic Anisotropy

Abstract

Antiferromagnetic (AFM) layers have been known to exert many effectson adjacent ferromagnetic (FM) layers, including coercivity enhancement, exchange bias, and magnetization switching.Several studies have suggested the magnetization reorientation can be induced by the uncompensated moment of the AFM layer at the AFM/FM interface [1]. Nevertheless, the effect of interfacial AFM moments on the induced PMA of adjacent FM layer is not fully clear.Here, we report an experimental investigation onthe effects of interfacial coupling of the AFM films on the induced perpendicular magnetic anisotropy (PMA) in epitaxially grown Mn/2 ML Co/14 ML Ni films. Magnetic hysteresis loops show that the PMA is established when monolayer Mn film was deposited. Further increasing the Mn layer thickness $(\mathrm{t}_{\text{Mn}})$ leads to presence of in-plane magnetic anisotropy. The PMA is established again while $\mathrm{t}_{\text{Mn}}$ is large than 6 ML (Fig 1(a)). Meanwhile, the structure of Mn is changed from c-fct to e-fct. Moreover, we also vary the interface properties by using Mn-based alloy AFM films. A significant change on the behavior of induced PMA is observed.According to these results, we indicate that antiferromagnet-induced PMA is highly sensitive to the interfacial moments of the AFM films and the magnetic interaction of such moments with the volume moment.