Current-induced magnetization switching in epitaxial L1_0-FePt/Cr heterostructures through orbital Hall effect

摘要

The current-induced magnetization switching (CIMS) was successfully observed in epitaxial L1_0-FePt/Cr_xPt_(1-x) (0 ≤ x ≤ 1) heterostructures grown by molecular beam epitaxy with large perpendicular magnetic anisotropy. With increasing Cr content, the critical switching current density (J_c) in FePt/Cr_xPt_(1-x) heterostructures exhibited a decreasing trend, where it was greatly reduced by 69 in FePt/Cr (3d) films compared to FePt/Pt (5d) films with strong spin-orbit coupling. Furthermore, the same switching polarities were observed for all FePt/Cr_xPt_(1-x) samples, indicating that the orbital Hall effect played a dominant role in CIMS for FePt/Cr films because of opposite spin Hall angles for Cr and Pt. Our results will put forward the applications of L1_0-FePt in collaboration with the orbital Hall effect from 3d metals in current-controlled magnetic random access memory and neuromorphic computing.