Modulation of thermal stability and spin–orbit torque in IrMn/CoFeB/MgO structures through atom thick W insertion

Antiferromagnet (AFM)/ferromagnet (FM) systems such as IrMn/CoFeB/MgO enable spin–orbit-torque- (SOT-) induced switching of perpendicular magnetization in the absence of an external magnetic field. However, the low thermal stability, weak perpendicular magnetic anisotropy (PMA), and indistinctive SO...

Full description

Saved in:
Bibliographic Details
Published in:Applied physics letters 2020-11, Vol.117 (21)
Main Authors: Xiong, Danrong, Peng, Shouzhong, Lu, Jiaqi, Li, Weixiang, Wu, Hao, Li, Zhi, Cheng, Houyi, Wang, Yuyan, Back, Christian H., Wang, Kang L., Zhao, Weisheng
Format: Article
Language:English
Subjects:
Antiferromagnetism
Applied physics
Atomic force microscopy
Electron energy
Electron energy loss spectroscopy
Electrons
Ferromagnetism
Heterostructures
Insertion
Magnesium oxide
Magnetic anisotropy
Magnetic switching
Magnetization
Modulation
Orbital stability
Spin-orbit interactions
Thermal stability
Thickness
Torque
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Antiferromagnet (AFM)/ferromagnet (FM) systems such as IrMn/CoFeB/MgO enable spin–orbit-torque- (SOT-) induced switching of perpendicular magnetization in the absence of an external magnetic field. However, the low thermal stability, weak perpendicular magnetic anisotropy (PMA), and indistinctive SOT of these AFM/FM heterostructures pose challenges to the practical application. Here, through the insertion of a thin W layer between the IrMn and CoFeB layers, we show that much larger effective PMA fields are obtained with annealing stability to 300 °C, which is guaranteed by the prevention of Mn diffusion via W insertion as shown in spherical aberration corrected transmission electron microscopy and atomic-resolution electron energy-loss spectroscopy measurement results. Furthermore, the spin–orbit torque is effectively tuned by changing the W layer thickness via modulation of the interfacial spin–orbit coupling at IrMn/W/CoFeB interfaces, which was reported to degrade the interface spin transparency for the spin currents. Finally, field-free magnetization switching was achieved with comparable exchange bias fields to samples without W insertion. This work demonstrates an effective strategy for improving the performance of the thermally robust AFM-based SOT device.
ISSN:0003-6951
1077-3118
DOI:10.1063/5.0029522