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

A large coercive field (E C ) and ultrahigh piezoelectricity are essential for ferroelectrics used in high-drive electromechanical applications. The discovery of relaxor-PbTiO 3 crystals is a recent breakthrough; they currently afford the highest piezoelectricity, but usually with a low E C . 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 C and ultrahigh piezoelectricity has become an imminent challenge. Herein, ternary Pb(Sc 1/2 Nb 1/2 )O 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 crystals are reported, wherein the dispersed local heterogeneity comprises abundant tetragonal phases, affording a E C of 8.2 kV/cm (greater than that of Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 by a factor of three) and ultrahigh piezoelectricity (d 33 = 2630 pC/N; d 15 = 490 pC/N). The observed E C 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.