Domain-pattern transfer across an artificial magnetoelectric interface

Abstract

Magnetoelectric interfaces provide efficient pathways for manipulating the magnetic order with lowpower-consuming electric fields. A prime example of this is the voltage-controlled domain-pattern transfer from a multiferroic BiFeO3 film into an amorphous Co0.9Fe0.1 ferromagnetic layer. Here we use a combination of optical second-harmonic generation and magnetic force microscopy to scrutinize the evolution of this transfer under voltage application. The nondestructive nature of our analysis permits the in operando examination of the magnetoelectric poling. We trigger ferroelectric switching events in BiFeO3 and track the evolution of their magnetoelectric transfer to the ferromagnetic domains of Co0.9Fe0.1 with spatial resolution. This reveals a wake-up effect in the magnetoelectric coupling across the interface. It is followed by simultaneous 90° rotations of the in-plane net polarization and net magnetization that progress with the increase of the voltage applied to the device.