Simultaneously achieving giant piezoelectricity and record coercive field enhancement in relaxor-based ferroelectric crystals.

A large coercive field (E) and ultrahigh piezoelectricity are essential for ferroelectrics used in high-drive electromechanical applications. The discovery of relaxor-PbTiO crystals is a recent breakthrough; they currently afford the highest piezoelectricity, but usually with a low E. Such performance deterioration occurs because high piezoelectricity is interlinked with an easy polarization rotation, subsequently favoring a dipole switch under small fields. Therefore, the search for ferroelectrics with both a large E and ultrahigh piezoelectricity has become an imminent challenge. Herein, ternary Pb(ScNb)O-Pb(MgNb)O-PbTiO crystals are reported, wherein the dispersed local heterogeneity comprises abundant tetragonal phases, affording a E of 8.2 kV/cm (greater than that of Pb(MgNb)O-PbTiO by a factor of three) and ultrahigh piezoelectricity (d = 2630 pC/N; d = 490 pC/N). The observed E enhancement is the largest reported for ultrahigh-piezoelectric materials, providing a simple, practical, and universal route for improving functionalities in ferroelectrics with an atomic-level understanding.