Exchange Bias Switching in an Antiferromagnet/Ferromagnet Bilayer Driven by Spin-Orbit Torque

Published

December 1, 2020

Author(s)

Shouzhong Peng, Daoqian Zhu, Weixiang Li, Hao Wu, Alexander Grutter, Dustin A. Gilbert, Jiaqi Lu, Danrong Xiong, Wenlong Cai, Padraic Shafer, Kang L. Wang, Weisheng Zhao

Abstract

Electrical manipulation of exchange bias and magnetization in antiferromagnet/ferromagnet thin films has been of great interest in recent years. Here, we experimentally demonstrate current-induced switching of exchange bias in perpendicularly magnetized IrMn/CoFeB bilayer structure by spin-orbit torque originating from the IrMn layer. It is found that a critical current density for exchange bias switching exists which is larger than that for magnetization reversal of the CoFeB layer. By manipulating the current direction and amplitude, independent switching of the magnetization and exchange bias can be repeatably achieved. The underlying mechanism is elucidated with X-ray magnetic circular dichroism, polarized neutron reflectometry measurements and micromagnetic simulations, whose results show that a small net magnetization within the IrMn interface plays a critical role for these phenomena. Our findings offer fundamental insight into electrical modulation of exchange bias and could enable novel functions for spintronic devices.

Citation

Nature Materials

Volume

3

Issue

12

Pub Type

Journals

Keywords

Magnetism, exchange bias, spintronics, spin-orbit torque, reflectometry, neutron scattering, X-ray spectroscopy

Citation

Peng, S. , Zhu, D. , Li, W. , Wu, H. , Grutter, A. , Gilbert, D. , Lu, J. , Xiong, D. , Cai, W. , Shafer, P. , Wang, K. and Zhao, W. (2020), Exchange Bias Switching in an Antiferromagnet/Ferromagnet Bilayer Driven by Spin-Orbit Torque, Nature Materials (Accessed October 11, 2024)