Antiferromagnetic (AFM) spintronics has aroused extensive research interest due to the high magnetic field (H-field) stability and ultrafast operation speed, making it a great candidate for next generation of spintronic applications. Despite its merits, the control of AFM orders remains challenging since the antiparallel AFMspins are extremely insensitive to external H-field. Existing researches mainly focus on the spin-polarized current control method, in which the large current density problem may hinder its practical application. As an alternative, electric field (E-field) control of antiferromagnetism through magnetoelectric (ME) coupling has aroused wide research interests in the last decade because it is a promising way to realize the fast, compact, and energyefficient spintronic devices. Due to the invisible AFM spins, the E-field control mainly relies on the indirect measurements like exchange bias. Nevertheless, the pinning effect at AFM–ferromagnetic (FM) interface is usually too strong to operate at room temperature.
To overcome these difficulties, the synthetic antiferromagnetic (SAF) multilayer with an FM/nonmagnetic (NM)/FM sandwich structure is considered as an easier way to manipulate the AFM orders. In this SAF multilayer structure with Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction, the top and bottom FM layers are coupled indirectly through the itinerant electrons in the NM middle layer. The interlayer exchange coupling (IEC) of the two FM layers can be parallelly or antiparallelly coupled, corresponding to the typical "0" or "1" state for information storage. Significant progress has been achieved in the voltage controllable SAFs via ionic liquid/gel gating method. Nevertheless, this gating method suffers from a recovery problem because of the limited electrochemical reaction. E-field control of RKKY interaction in a clean and fully reversible manner, which is at a premium for the development of novel spintronic devices, remains unachieved.
In this paper, we demonstrated a new approach toward E-field controllable AFM–FM coupling switching at room temperature based on the FeCoB/Ru/FeCoB/(011) Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) multiferroic heterostructures.
This paper contains both experimental and theoretical works. The experiments are performed by Xinjun Wang in N. X. Sun's group in Northeastern University in USA and Qu Yang in Prof. Ming Liu's group with the help of Prof. Ziyao Zhou in The School of the Electronic and Information Engineering, Xi'an Jiaotong University and the theoretical part is carried out by Lei Wang in Prof. Tai Min's group in The School of Material Science and Engineering, Xi'an Jiaotong University.
文章链接：https://onlinelibrary.wiley.com/doi/10.1002/adma.201803612
