Large Spin Hall Conductivity in Epitaxial Thin Films of Kagome Antiferromagnet Mn3Sn at Room Temperature

Abstract Mn 3 Sn is a non‐collinear antiferromagnetic quantum material that exhibits a magnetic Weyl semimetallic state and has great potential for efficient memory devices. High‐quality epitaxial c ‐plane Mn 3 Sn thin films have been grown on a sapphire substrate using a Ru seed layer. Using spin pumping induced inverse spin Hall effect measurements on c ‐plane epitaxial Mn 3 Sn/Ni 80 Fe 20 , spin‐diffusion length (), and spin Hall conductivity (σ SH ) of Mn 3 Sn thin films are measured: nm and cm −1 . While is consistent with earlier studies, σ SH is an order of magnitude higher and of the opposite sign. The behavior is explained on the basis of excess Mn, which shifts the Fermi level in these films, leading to the observed behavior. These findings demonstrate a technique for engineering σ SH of Mn 3 Sn films by employing Mn composition for functional spintronic devices.