Recent progress in piezoelectric properties of lead-free perovskite sodium potassium niobate

Piezoelectric ceramics are some of the most important class of functional materials which are used to produce sensors, actuators, motors, resonators, electromagnetic filters, etc. Among various piezoceramics, the perovskite family has grabbed significant attention, particularly in the fields of condensed matter physics. Precisely speaking, Lead Zirconate Titanate exhibits remarkable dielectric and piezoelectric properties, however, the toxic nature of lead is hazardous to both environment and human beings. Therefore, various researchers have shifted their focus towards lead-free piezoceramics. Sodium Potassium Niobate is the most intensively studied lead-free piezoelectric material possessing large piezoelectric coefficient and high Curie temperature. The objective of this paper is to provide an insight on the dielectric and piezoelectric properties of lead-free Sodium Potassium Niobate ceramics and their composites. The current state-of-art of this lead-free system with an emphasis on recent advances in its piezoelectricity suitable for wide range of applications are also been highlighted. This review provides an overview of the development of lead-free perovskite Sodium Potassium Niobate and its composites which may provide an impetus to various researchers working in the field of materials science.