Controllable Conical Magnetic Structure and Spin-Orbit-Torque Switching in Symmetry-Broken Ferrimagnetic Films

Published

January 23, 2024

Author(s)

Yaqin Guo, Jing Zhang, Purnima Balakrishnan, Alexander Grutter, Baishun Yang, Michael R. Fitzsimmons, Timothy Charlton, Haile Ambaye, Xu Zhang, Hanshen Huang, Zhi Huang, Jinyan Chen, Chenyang Guo, Xiufeng Han, Kang Wang, Hao Wu

Abstract

Exploring and controlling chiral spin textures has attracted enormous interest from the perspective of fundamental research and spintronic applications. Here, we report the emergence of spiral spin states, bulk spin-orbit torque (SOT), and the Dzyaloshinskii-Moriya interaction (DMI) induced with the combination of Bloch- and Néel-type in a single Gd-Fe-Co layer with a vertical composition gradient. Using polarized neutron reflectometry, the magnetization M is found to rotate with depth through the gradient, due to the nonzero out-of-plane DMI (DOOP). Meanwhile, the deterministic SOT magnetization switching in a single Gd-Fe-Co layer without a heavy metal, where the sign of the bulk SOT and in-plane DMI (DIP) is governed by the direction of the composition gradient. The presented results pave the way for flexibly engineering the spin currents and DMI in the ferrimagnetic materials, which have potential applications for future ferrimagnetic SOT devices.

Citation

Physical Review Applied

Volume

21

Issue

1

Pub Type

Journals

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https://doi.org/10.1103/PhysRevApplied.21.014045

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Keywords

spintronics, spin-orbit torques, helical magnetism, ferrimagnets, graded films, polarized neutron reflectometry

Citation

Guo, Y. , Zhang, J. , Balakrishnan, P. , Grutter, A. , Yang, B. , Fitzsimmons, M. , Charlton, T. , Ambaye, H. , Zhang, X. , Huang, H. , Huang, Z. , Chen, J. , Guo, C. , Han, X. , Wang, K. and Wu, H. (2024), Controllable Conical Magnetic Structure and Spin-Orbit-Torque Switching in Symmetry-Broken Ferrimagnetic Films, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.21.014045, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936487 (Accessed October 14, 2025)