Manipulation of spin–orbit torque and Dzyaloshinskii-Moriya interaction by varying Mn concentration in Pt1-xMnx/Co bilayer

• Published in: Journal of magnetism and magnetic materials 2023-11, Vol.585, Article 171141
• Main Authors: Xie, Zhicheng, Zhao, Zhiyuan, Sun, Yiming, Yang, Yumin, Sun, Hongli, Qin, Hongrui, Cao, Ying, Lei, Na, Zhao, Jianhua, Wei, Dahai
• Format: Article
• Language: English
• Subjects: Dzyaloshinskii-Moriya interaction; Magnetization switching; Power consumption; Spin-orbit torque
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2023.171141

•The Mn concentration x dependence of damping-like SOT efficiency (ξDL) Pt1-xMnx/Co bilayer is nonmonotonic with a maximum of 0.254 appearing around x = 0.2, which is attributed to the enhancement of the resistivity ρPtMn.•The Dzyaloshinskii-Moriya interaction (DMI), modulated by the interfacial SOC, is also tunable by x with the maximum value appearing around x = 0.15. Therefore, modulation of × makes it easy to tune DMI.•A significantly reduced critical current density (JC) as low as 3.75×106 A/cm2 is achieved by the alloying of Mn in Pt. This not only depends on the enhancement of ξDL, but also benefits from the attenuation of effective perpendicular magnetic anisotropy energy density.•This work highlights the potential of alloying Pt with Mn as a valuable means to achieve high-performance SOT spintronic devices. Reducing critical current density (JC) of current-driven magnetization switching via power-efficient spin–orbit torque (SOT) is a key challenge in spin-based memory and logic devices. The Pt1-xMnx alloy shows prospect for enhancing the damping-like SOT efficiency (ξDL) while maintaining relatively low resistivity and power consumption. In this work, we investigated the Mn concentration x dependence of ξDL in Pt1-xMnx/Co bilayer and observed a nonmonotonic variation with the maximum ξDL ≈ 0.25 appearing around x = 0.2. The increase of the Pt1-xMnx layer resistivity is the main contribution to the enhancement of ξDL. Mn atoms doped in Pt not only modulate ξDL originating from the spin Hall effect of the Pt1-xMnx layer, but also affect the interfacial phenomena at the Pt1-xMnx/Co interface. We find that the related interfacial Dzyaloshinskii-Moriya interaction (DMI) is also tunable by x with the maximum appearing around x = 0.15. The significantly reduced JC of Pt1-xMnx/Co bilayer is mainly due to the enhancement of ξDL and the attenuation of effective perpendicular magnetic anisotropy energy density. Meanwhile, Pt1-xMnx/Co bilayer maintains low power consumption and necessary thermal stability. Our work highlights the potential of alloying Pt with Mn as a valuable means to achieve high-performance SOT spintronic devices.