Lead-free piezoelectrics solutions

In addition to BZT-xBCT, the other system that has been studied extensively by the researchers for both fundamental understanding and applications is sodiimi bismuth titanate, Nao.5Bio.5Ti03 (NBT). NBT and its solid solutions have been extensively studied because of their exceptionally high electrostrain [20,21]. In addition, NBT coidd be a potential candidate in the search for lead-free piezoelectric materials. From the structural aspects, NBT is... 

Certain ternary solid solutions containing BTO as one of their major phase components show excellent piezoelectric properties in the vicinity of MPB. They have been considered as a potential replacement for existing lead-based piezoelectric perovskite, PbZrOs-PbTiOs, PMT-PT, and so on. In fact, the extremely high piezoelectric response of PZT and PMN-PT has been partially attributed to the presence of a MPB between rhombohedral and tetragonal phases at that concentration [12]. Therefore, the presence of a MPB is considered as a necessary component of a lead-free replacement material due of the enhancement in properties observed for compositions at or near MPB. The basic approach to achieve high piezoelectricity is to choose the composition of the material at the proximity of a MPB of the phase diagram. The strong piezoelectric and dielectric responses at the vicinity of MPB have been ascribed to the low polarization anisotropy (rotation of FE polarization between two equivalent states) and elastic softness at MPB. 

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