Abstract
A variety of exciting phenomena have been discovered using 109° domain walls in BiFeO3 thin films, such as domain wall conductivity, photovoltaic effects, and magnetoelectric coupling effects. The control of these physical properties with an electric field plays a key role in the development of nanoelectric devices. Therefore, it is critical to fabricate 109° periodic domain walls with a bottom electrode. However, the introduction of a bottom electrode favors the formation of a 71° domain structure due to the electrostatic boundary conditions. In this study, pulsed laser deposition (PLD) is used to produce multilayer epitaxial thin films. A 25% La doping BiFeO3 layer is inserted as the dielectric spacer between the bottom electrode SrRuO3 layer and the pure BiFeO3 layer, enabling the fabrication of 109° periodic domain walls engineered by an interface effect-depolarization field. Moreover, the fabrication of the 109° domain structure with a bottom electrode enables the study of its switching behavior. This protocol provides a novel route to produce 109° periodic domain walls and opens a new pathway to explore fascinating phenomena, such as the room-temperature electric field control of exchange bias in a ferromagnet/BiFeO3 system and room-temperature multiferroic vortices in BiFeO3.
