Development in Lead-Free Perovskite Piezoelectric Bulk Materials

Piezoelectric materials possess unique ability to interconvert electrical and mechanical energy, enabling their application in a variety of important areas like harvesting energy, high-power applications, sensing and actuation, and more. In this regard, lead titanate and other lead-based perovskites have been commercialized due to their compelling dielectric and ferroelectric properties. However, growing environmental concerns regarding lead exposure during the synthesis and integration of lead-based materials in highperformance applications led to the enforcement of restrictive laws and regulations. A major part of the ongoing research in this field is more or less influenced by the desire to develop lead-free substitutes 516 that have either comparable or, in some cases, better piezoelectric properties. As a potential substitute, perovskite ceramics have gained considerable interest because of their characteristic feature to respond to applied electrical fields as well as for the ease of tuning properties simply by making any compositional change. This chapter delves into the latest developments in lead-free piezoelectric perovskites (LFPP), providing a thorough overview of the crystallographic structures, polarization mechanisms, and material properties of BaTiO 3 , BiFeO 3 , Bi 0.5 Na 0.5 TiO 3 , and (K, Na) NbO 3 , which all contribute to their piezoelectric behavior. Finally, current challenges and prospects associated with LFPPs based on their performance have been discussed.