Field-Free Magnetization Switching in a Ferromagnetic Single Layer through Multiple Inversion Asymmetry Engineering

• Published in: ACS nano Vol. 16; no. 8; pp. 12462 - 12470
• Main Authors: Huang, Qikun, Guan, Chaoshuai, Fan, Yibo, Zhao, Xiaonan, Han, Xiang, Dong, Yanan, Xie, Xuejie, Zhou, Tie, Bai, Lihui, Peng, Yong, Tian, Yufeng, Yan, Shishen
• Format: Journal Article
• Language: English
• Published: American Chemical Society 23.08.2022
• Subjects: composition gradient; magnetization switching; oblique sputtering; spin−orbit torque; inversion asymmetry
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.2c03756

A simple, reliable, and self-switchable spin–orbit torque (SOT)-induced magnetization switching in a ferromagnetic single layer is needed for the development of next generation fully electrical controllable spintronic devices. In this work, field-free SOT-induced magnetization switching in a CoPt single layer is realized by broken multiple inversion symmetry through simultaneously introducing both oblique sputtering and a vertical composition gradient. A quantitative analysis indicates that multiple inversion asymmetries can produce dynamical bias fields along both z- and x-axes, leading to the observed field-free deterministic magnetization switching. Our study provides a method to accomplish fully electrical manipulation of magnetization in a ferromagnetic single layer without the external magnetic field and auxiliary heavy metal layer, enabling flexible design for future spin–orbit torque-based memory and logic devices.