Controllable electrical, magnetoelectric and optical properties of BiFeO3 via domain engineering

Bismuth ferrite (BiFeO 3 , BFO) as one of the few single-phase room-temperature multiferroics, has aroused ever-increasing enthusiasm in research communities during the past two decades. The robust ferroelectricity, promising magnetoelectric coupling and remarkable optical behaviors of BFO all enrich its physical phenomena and functional properties. The microscopic ferroic domain structures in BFO determine both the static configurations and dynamic behaviors of order parameters, which is the fundamental basis for understanding and controlling of macroscopic properties. Here, we provide a comprehensive and up-to-date review of the intensive research advances of BFO, in the framework of domain engineering. We begin with an introduction to the rich domain structures of BFO and typical domain engineering strategies, such as chemical modification, electrostatic boundary control, strain engineering, substrate engineering, etc. Then, electrical properties (ferroelectricity, piezoelectricity and conduction), magnetoelectric couplings and optical effects (photovoltaic, photocatalytic, mechanical-optical, etc.) modulated by domain engineering in BFO are discussed in sequence. Remarkable electrical, magnetic and optical phenomena at the domain walls of BFO, which have been discovered and intensively explored recently, are also summarized. Finally, remaining challenges and perspectives are proposed for further domain engineering in BFO-based functional materials, devices and applications.