Piezoelectric response of disordered lead-based relaxor ferroelectrics

Abstract

Lead-based relaxor ferroelectric perovskite oxides, exemplified by the (1–x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN-PT) solid solution, are a group of multifunctional materials with unique dielectric and piezoelectric properties. The long-lasting question that has intrigued the research community for decades is whether and to which extent the disordered relaxor nature of these materials is implicated in the exceedingly large piezoelectric response observed in both single crystals and ceramics. In this Perspective, focusing on PMN-PT, I briefly review and discuss the current understanding of the polar structure of relaxor ferroelectrics, followed by its possible implications in the large piezoelectricity. A critical review of the existing data confirms a significant progress made in recent years while opening up new questions related to the structure-property relations in these complex materials.