Defects-Induced Multifunctional Properties in BiFeO3

BiFeO3 has been the prime choice of multiferroic research, particularly over the past two decades. The rhombohedrally distorted perovskite exhibits weak coupling between the ferroelectric (TC ~ 1120 K) and magnetic (TN ~ 643 K) order parameters above room temperature, observed only in a few other systems. All the research carried out on this material so far is principally centered on strengthening the innate magnetoelectric coupling, in a view to realize suitable applications. Alongside, BiFeO3 gained prominence of equal scale in photovoltaic, photocatalytic, and photo-ferroelectric applications. Above and beyond, recent years witnessed a gush of reports on the underlying defect physics and their inarguable influence on the physical properties. This chapter aims to provide a glimpse of defect-induced properties, focusing on the magnetic property variation in BiFeO3 in the presence of defects and allied phenomena. To help readers gain an overall understanding, a short account of how defects modulate the ferroelectric, magnetoelectric, optical, and photovoltaic properties is also included.