| Abstract Scope |
In this talk, I will present a series of recent investigations on the structure-property relationships in epitaxial thin films made of the prototypical relaxor ferroelectric 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 (PMN-PT). First, I will present the work on the epitaxial strain dependence of domain structures and dielectric and ferroelectric properties in PMN-PT thin films. Next, I will present the work on the relationship between polarization rotation and polar nanodomains using a multi-scale approach that probes the structural evolution in both the average unit-cells and polar nanodomains. We observed that the boundary between (pseudo-)rhombohedral and (pseudo-)tetragonal crystal structures of unit-cells is located in the same region of the strain-electric-field diagram as the boundary between ellipsoidal and cylindrical polar nanodomains, which are elongated along the <011> and [001], respectively, which implies that structural transitions between polar nanodomain configuration underpins the polarization rotation and large electromechanical coupling of relaxors. |