Controllable magnetic topology transformations in van der Waals ferromagnets (Fe1-Co )5GeTe2

Understanding and manipulating versatile topological spin textures in two-dimensional (2D) van der Waals (vdW) magnetic materials has elicited considerable interest, which aims to establish a robust platform for 2D spintronic applications. In this study, we demonstrate the topological magnetic transformation among the magnetic vortex, stripe domain, and meron chains within the ab plane of (Fe 1-x Co x ) 5 GeTe 2 (FCGT), which could be induced by chemical substitution and simple electron beam convergence. Micromagnetic simulations corroborate that the emergence of the topological meron chain is strongly associated with localized decreases in magnetic anisotropy. Furthermore, room temperature spin textures and the corresponding dynamics under in-plane magnetic fields are compared in 20% doped FCGT to manifest the doping effects. These findings offer insights into engineering room temperature spin textures in vdW ferromagnets and their potential applications in spintronic devices.