Coexisting Non-Trivial Van der Waals Magnetic Orders Enable Field-Free Spin-Orbit Torque Magnetization Dynamics.

Zhao, Bing; Bainsla, Lakhan; Ershadrad, Soheil; Zeng, Lunjie; Ngaloy, Roselle; Svedlindh, Peter; Olsson, Eva; Sanyal, Biplab et al. · Adv Mater · 2025

basic_science · Level V

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Abstract

The discovery of van der Waals (vdW) magnetic materials exhibiting non-trivial and tunable magnetic interactions can lead to exotic magnetic states that are not readily attainable with conventional materials. Such vdW magnets can provide a unique platform for studying new magnetic phenomena and realizing magnetization dynamics for energy-efficient and non-volatile spintronic memory and computing technologies. Here, the coexistence of ferromagnetic and antiferromagnetic orders in vdW magnet (Co<sub>0.5</sub>Fe<sub>0.5</sub>)<sub>5-x</sub>GeTe<sub>2</sub> (CFGT) above room temperature, inducing an intrinsic exchange bias and canted perpendicular magnetism is discovered. Such non-trivial intrinsic magnetic order enables to realize energy-efficient, magnetic field-free, and deterministic spin-orbit torque (SOT) switching of CFGT in heterostructure with Pt. These experiments, in conjunction with density functional theory and Monte Carlo simulations, demonstrate the coexistence of non-trivial magnetic orders in CFGT, which enables field-free SOT magnetization dynamics in spintronic devices.