Structural Evidence for Strong Coupling between Polarization Rotation and Lattice Strain in Monoclinic Relaxor Ferroelectrics

Abstract

Morphotropic phase boundary type piezoelectric materials have been widely used in the modern society. The study of its crystal structure and polarization is of great fundamental importance in understanding its nature of extraordinary piezoelectric properties. In this study, in-situ high-energy synchrotron X-ray diffraction combined with 2D geometry scattering technology has been carried out to ascertain the constitutive relationship of high-performance Pb(Mg1/3Nb2/3)O3-PbTiO3 relaxor ferroelectric ceramics. It is intriguing to find that electric-field-induced single monoclinic phase can exist stably. The lattice and polarization of monoclinic structure response significantly and flexibly to external electric field, that is, the lattice displays a butterfly shape under stimulation of bipolar electric field while its polarization continuously and reversibly rotates between monoclinic MA and MB regions. Importantly, direct experimental evidence reveals that there is a strong coupling role between lattice str...