Local structures and temperature-driven polarization rotation in Zr-rich PbZr_{1- x}Ti_xO₃

PbZr_1-xTi_xO₃, which has abundant structural variations in the corresponding physical properties, has been used in a large variety of applications. To understand the effect of the structure on its high-performance piezoelectric properties, its local and average structures are studied. Total scattering data have been obtained from high-energy synchrotron powder diffraction experiments at 20 K and 300 K. Using the reverse Monte Carlo method, information on cation displacements has been extracted from X-ray Pair Distribution Function data. This suggests that the local disorder of the B cations is mainly driven by thermal motion, while the local disorder of Pb is most likely caused by more complex factors, such as displacive disorder. Both rhombohedral and monoclinic local polarizations are observed in Zr-rich PZT, whose directions depend on temperature.