Influence of heavy-metal capping layers on perpendicular magnetic anisotropy and spin-orbit torques of Pt/Co/HM stacks structures. (June 2021)

• Record Type: Journal Article
• Authors: Zhao, R.H.; Ren, Z.Y.; Cao, J.P.; Yuan, Y.S.; Zhao, G.L.; Xu, X.G.; Meng, K.K.; Miao, J.; Jiang, Y.
• Is Part Of: Solid state communications. Volume 332(2021)
• Publication Date: 2021-06
• Subjects: Spin-orbit torques -- Perpendicular magnetic anisotropy -- Heavy metal; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2021.114340
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: The influence of perpendicular magnetic anisotropy (PMA) and current-induced magnetization switching on different capping materials, especially heavy metal (HM) materials has been rarely studied. In this work, the dependence of HM capping layer on interfacial PMA and current-induced magnetization switching in Pt/Co/HM tri-layered structures were investigated, where HM is Ta, Pt and W. We found that the Co/HM interface play a significant role on the PMA. Especially, the structure with a Ta capping layer features the largest anisotropy energy density K U of 3.15 Merg/cm 3 and the largest spin-orbit torques (SOT) switching efficiency η S O T of 0.19, which can be attributed to the different spin-orbit coupling and interfacial hybridization between Co and HM layers. Furthermore, the Pt/Co/Ta structure has dissimilar metals (Pt and Ta) with opposite spin Hall angles on the opposite sides of the ferromagnetic Co. We also investigated the Co layer thickness t Co dependence of PMA and switching current density, indicating the lower switching field can reduce the switching current density in the PMA region. Highlights: The perpendicular magnetic anisotropy and current-induced magnetization switching of Pt/Co/heavy metal was carried out. The Pt/Co/Ta shows the largest anisotropy energy density and the largest spin-orbit torques switching efficiency. The lower switching field can reduce the switching current density in the PMA region. This findings will provide helpful information for the design of multilayers.