Enhanced antiferromagnet-induced perpendicular magnetic anisotropy by Bi atomic layer with high spin–orbit coupling

Abstract

Antiferromagnetic (AFM) thin films have emerged as promising candidates for inducing perpendicular magnetic anisotropy (PMA) in adjacent ferromagnetic (FM) layers. In this work, we demonstrate that capping with a Bi atomic layer enhances the antiferromagnet-induced PMA in Mn(FeMn)/Co/Ni(Fe) films when Mn(FeMn) transitions to the AFM state. Moreover, the Bi atomic layer stabilizes the antiferromagnet-induced PMA at elevated temperatures, maintaining its effects until the long-range AFM order is lost. This enhancement is attributed to the strong spin–orbit coupling of the Bi atomic layer, which reinforces the out-of-plane spin components of AFM moments, thereby amplifying the induced PMA. Our findings provide valuable insights into the interaction between 6p-Bi atomic layers and AFM moments, underscoring their critical role in inducing PMA in adjacent FM layers under demanding thermal conditions. This approach shows significant potential for advancing AFM-based spintronic systems, particularly in applications requiring robust thermal stability.