Interplay between pressure and local symmetry in(Pb1−3/2xLax)(Zr60Ti40)O3: Emergence of a relaxor state

Abstract

This study aims at inquiring into the role of hydrostatic pressure in driving the relaxor behavior within a local-symmetry-based approach to relaxor ferroelectrics. Results reveal the occurrence of a pressure-induced ferroelectric-to-relaxor crossover, clearly reflected in the experiment-matching temperature-pressure phase diagram of lanthanum-modified lead zirconate titanate. Relaxor behavior is found to occur under pressure and upon cooling due to the nucleation of local order within fractal regions, as an incipient state towards percolating ferroelectric order. Further analysis of the geometrical features of ordering process points to a manifest nontrivial disruption of the balance between competing interactions under the conjugated effects of pressure and local-symmetry constraints.