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

TL;DR

This study demonstrates that mechanical force can switch both ferroelectric and magnetic domains in a Bi0.9La0.1FeO3 thin film at room temperature, revealing new possibilities for multiferroic device control through electro-elastic and magneto-electric coupling.

Contribution

It introduces the novel use of mechanical force to simultaneously switch ferroelectric and magnetic domains in a multiferroic thin film, expanding control methods beyond electric and magnetic fields.

Findings

Mechanical force induces polarization and magnetization switching.

High strain gradients cause ferroelastic and domain flipping.

Both domains can be controlled at room temperature.

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 polarization and magnetization switching were investigated 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 electric field. High strain gradient created by mechanical force is demonstrated as able to induce ferroelastic switching and thus induce both ferroelectric dipole and magnetic spin flipping in our thin film, 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.