Tuning of current-induced effective magnetic field through Rashba effect engineering in hybrid multiferroic structures

Abstract

Current-induced effective magnetic fields offer a new pathway through spin orbit interaction (SOI) to switch magnetization and have recently attracted great interest. In the conventional heavy metal/ferromagnetic metal/oxide (HM/FM/Oxide) structure, significant efforts have been made to study the role of the HM in determining effective magnetic fields. However, very little attention has been paid to the oxide layer and its interface with FM, where the Rashba effect may affect the effective field. In this report, we present a pathway to tune the effective magnetic field by engineering the Rashba effect in a hybrid multiferroic multilayer structure. A ferroelectric oxide of BaTiO 3 , whose polarizations either up or down are controlled by interface engineering, was introduced into the conventional SOI multilayer with the structure of BaTiO 3 /CoFeB/Pt. The current-induced effective magnetic fields increase by more than 200% when the ferroelectric polarization of BaTiO 3 changes from up to down. The changes in the effective magnetic field are mainly attributed to the different Rashba effective fields induced by the opposite ferroelectric polarizations. Our study offers a new path towards controlling the current-induced effective magnetic field and may pave the way for integrating other functional oxides into the spintronic devices.

Tuning Effective Spin Hall Angles via Oxygen Vacancies in Multiferroic BiFeO3‐Based Heterostructures

“…On the other hand, in the BFO films with different polarization fields, the migration of oxygen vacancies may affect the oxidation level of the thin films neighboring to BFO . If we deposit a FM/HM structure on a BFO film, the different polarization fields of BFO should affect SOT through the indirect control of the oxidation level in the FM layer, which is completely different from previous studies on PMN‐PT, ionic liquid gate, and BTO …”

“…Yang et al reported the electric‐field control of SOTs in a Pt/Co/GdO x heterostructure through oxygen ions migration . And Chen et al had used a ferroelectric oxide of BaTiO 3 to tune the field‐like effective field by engineering the Rashba effect, which can only be observed at low temperatures (≈10 K). However, how to realize effective and stable control of SOT by multiferroic materials and their polarization fields above room temperature remains a challenge.…”

Rashba–Edelstein Effect in the h‐BN Van Der Waals Interface for Magnetization Switching

“…Here, the quantified current‐induced spin–orbit field refers to the damping‐like effective field that is the driving force for the magnetization switching. [ 18 ] Figure 2d shows the AHE loops at ±1.5 mA under a bias IP magnetic field of 8.5 kOe. It can be seen that the AHE loops shift toward opposite directions under opposite DC, indicating the existence of a current‐induced effective field due to the SOT.…”

Regulating Interfacial Spin Hall Conductivity with Ferroelectricity

“…However, further enhancement of controlling SHE and even the sign by applying an external voltage bias is limited by the magnitude of the electric field itself. On the other side, ferroelectric materials that can generate strong electric fields through spontaneous polarization hold promise for offering nonvolatile control of various spintronic devices. − …”