BiFeO₃-based lead-free materials: Recent breakthroughs and their multifunctional applications

Multiferroic materials have gone through significant advancement and attracted widespread attention due to their multifunctional characteristics and discovery of various new physical phenomena. Among the few available single phase multiferroic materials, BiFeO₃ (BFO) is one of the most versatile single-phase material which exhibit multiferroic characteristics at room temperature. The new age microelectronics devices are getting scaled to significantly smaller dimensions due to improvement in storage density and speed, and therefore, reduction in energy dissipation in the form of heat has become one of the most important issue in microelectronics industry. Multiferroic materials can deliver various new functionalities along with ultra-low energy consumption, which is attributed to a strong correlation between ferroic orders (i.e., magnetism, ferroelectricity, and piezoelectricity). In this review article, we review the various developments and advances in BiFeO₃ based lead-free materials and also highlighted the challenges in the synthesis and design of BiFeO₃ based materials. The article focuses on understanding the effect of various substituents/dopants on the electrical, magnetic, and magnetoelectric properties of in BiFeO₃ based materials. Further, the article will also develop an understanding of various mechanisms of voltage control of ferromagnetism and nature of exchange coupling in BiFeO₃ based solid solutions, composites, and heterostructure.