Role of Zinc and Niobium in the Giant Piezoelectric Response of   PbZn1/3Nb2/3O3
  Relaxor ferroelectric perovskites are highly polarizable and can exhibit giant coupling between elastic strain and an applied electric field. Here, we report an in situ extended X-ray absorption fine structure (EXAFS) study of a PbZn1/3Nb2/3O3 (PZN) single crystal as a function of the electric field. We show that the strong dipoles in the NbO6 octahedra bonds are aligned along the four \textless{} 011 \textgreater{} directions close to the orientation of the electric field, while a small reversible polar shift occurs for Zn in the direction of the electric field, i.e., positive or negative. This reversible Zn-O polar shift is proposed to play an important role in both the "easy" switching of the ferroelectric polarization and the giant piezoelectric effect in PZN. 
Ali Al-Zein (L2C), Hichem Dammak (SPMS), Philippe Papet (ICG ICMMM),   Olivier Mathon (ESRF), Bernard Hehlen (L2C), Claire L...
cond-mat.mtrl-sci