Bridging experiment and theory of relaxor ferroelectrics with multislice electron ptychography

Introducing structural and/or chemical heterogeneity into otherwise ordered crystals can dramatically alter material properties. Lead-based relaxor ferroelectrics such as 0.68Pb(Mg_1/3Nb_2/3)O₃-0.32PbTiO₃ are prototypical examples. We performed three-dimensional (3D) volumetric characterization using multislice electron ptychography (MEP) and bond valence molecular dynamics (BVMD) simulations. Real-space comparisons between the two under varying strain states revealed a coherent 3D view of the "polar slush." Dipolar correlations from the atomic to domain scales are shown to be jointly modulated by strain and chemical configurations, with the best agreement found in a model accounting for both overall chemical disorder and residual short-range order. Together, MEP and BVMD provide a framework for linking atomic-scale heterogeneity in complex materials by means of complementary 3D imaging and predictive modeling.