High switching ratio of antiferromagnetic order in thick sputtered Mn3+xSn1−x films by spin–orbit torque

Abstract

Electrical manipulation of the antiferromagnetic states of Weyl semimetal Mn3Sn by current-induced spin–orbit torque (SOT) has attracted intensive attention recently, largely due to its potential advantage for high-density integration and ultrafast operation. In this study, the relation between the antiferromagnetic SOT switching ratio and the composition of Mn3+xSn1−x films was explored systematically. While SOT manipulation of ferromagnetic order has traditionally been confined to films just a few nanometers in thickness, our results indicate that current-induced SOT can effectively switch the antiferromagnetic order of sputtered Mn3+xSn1−x films with a thickness of up to 100 nm. Notably, a high electrical switching ratio of 83% was obtained in the optimized film with a composition of Mn3.1Sn0.9. The switching of the octupole polarization in thick Mn3Sn films may be accounted for by a seeded SOT mechanism. Joule heating of the Mn3Sn film close to the Néel temperature plays a key role in this switching process. Additionally, the factors influencing the switching ratio were further investigated. This work will deepen our understanding of the electrical switching mechanism of non-collinear antiferromagnetic order in Mn3Sn film and promote the development of antiferromagnetic spintronic devices.