Switching of both local ferroelectric and magnetic domains in multiferroic Bi0.9La0.1FeO3 thin film by mechanical force

Tingting Jia,Hideo Kimura,Zhenxiang Cheng,Hongyang Zhao

doi:10.1038/srep31867

Abstract

Cross-coupling of ordering parameters in multiferroic materials by multiple external stimuli other than electric field and magnetic field is highly desirable from both practical application and fundamental study points of view. Recently, mechanical force has attracted great attention in switching of ferroic ordering parameters via electro-elastic coupling in ferroelectric materials. In this work, mechanical force induced both polarization and magnetization switching were visualized in a polycrystalline multiferroic Bi0.9La0.1FeO3 thin film using a scanning probe microscopy system. The piezoresponse force microscopy and magnetic force microscopy responses suggest that both the ferroelectric domains and the magnetic domains in Bi0.9La0.1FeO3 film could be switched by mechanical force as well as by electric field. High tip stress applied on our thin film is demonstrated as able to induce ferroelastic switching and thus induce both ferroelectric dipole and magnetic spin flipping, as a consequence of electro-elastic coupling and magneto-electric coupling. The demonstration of mechanical force control of both the ferroelectric and the magnetic domains at room temperature provides a new freedom for manipulation of multiferroics and could result in devices with novel functionalities.

Highlights

Locally mechanical manipulation of ferroelectric and magnetic orders
It has been reported that giant magneto-elastic coupling can lead to atomic displacements and give rise to strong ME coupling in rare earth magnets[12], which may lay a solid foundation for the possible experimental switching of magnetic domains by mechanical force in multiferroic materials
This study provides an understanding of the ME coupling in a polycrystalline multiferroic Bi0.9La0.1FeO3 thin film to manipulate both ferroelectric and magnetic domains by applying mechanical force and electric field, which opens a new route to design magnetoelectric devices

Summary

Introduction

Locally mechanical manipulation of ferroelectric and magnetic orders. the mechanical-force-induced ferroelectric phase transition in multiferroic BiFeO3 thin film has been studied experimentally[11], to the best of our knowledge, mechanical force induced switching of both magnetic and ferroelectric domains has never been realized in any multiferroic material. In order to investigate the effect of tip stress on both ferroelectric domain and magnetic domain in a multiferroic material, we use PFM to apply nanoscale mechanical force on nanomaterials through a probe tip, and scan the ferroelectric response and magnetic phase in a Bi0.9La0.1FeO3 thin film by changing the working mode from PFM to magnetic force microscopy (MFM). We switched magnetic domains as well as ferroelectric domains using an electrical field Both ferroelectric and magnetic domain switching were successfully demonstrated by mechanical force as well as by electric field, revealing the complex coupling among polarization, magnetization, and strain in multiferroic BLFO thin film. This study provides an understanding of the ME coupling in a polycrystalline multiferroic Bi0.9La0.1FeO3 thin film to manipulate both ferroelectric and magnetic domains by applying mechanical force and electric field, which opens a new route to design magnetoelectric devices

Methods

Results

Conclusion