Atomic-Level Electric Polarization in Entropy-Driven Perovskites for Boosting Dielectric Response.

Dielectric oxides with robust relaxation responses are fundamental for electronic devices utilized in energy absorption, conversion, and storage. However, the structural origins governing the dielectric response remain elusive due to the involvement of atomically complex compositional and structural environments. Herein, configurational entropy is introduced as a regulatory factor to precisely control the structural heterogeneity in representative perovskite dielectric oxides. Through advanced structural and electric field visualization studies, a novel quantitative relationship is established between atomic-level structural disorder-induced electric field polarization and macroscopic dielectric properties. The results indicate that the degree of atomic delocalization in perovskite oxides exhibits a near-parabolic trend with increasing entropy, reaching a maximum in medium-entropy perovskite. Correspondingly, the atomic electric field vectors display significant asymmetrical distribution, thus greatly enhancing angstrom-scale electric field polarization. Then, it is experimentally proven that entropy-driven electric polarization can improve the dielectric relaxation behavior characterized by broader frequency and stronger intensity of electromagnetic energy absorption, with improvements of approximately 160% and 413% compared to structurally homogeneous control. This study unveils the quantitative correlation between angstrom-scale electric field polarization and dielectric response in perovskite oxides, offering a novel perspective for exploring the structure-property relationship in dielectric materials.