Heterogeneous Antiferroelectric Ordering in NaNbO3–SrSnO3 Ceramics Revealed by Direct Superstructure Imaging

NaNbO3-based antiferroelectric materials offer a promising pathway towards greener and more cost-effective energy storage devices.However, their intrinsic structural instabilities often lead to reduced energy density that compromises their performance and longevity.In this brief communication, we demonstrate how Dark-Field X-ray Microscopy -when carried out on the characteristically weak 1/4{843}pc superstructure reflection -can map the antiferroelectric phase and its strain heterogeneity in typically small, deeply-embedded grains of a NaNbO3 and 0.95NaNbO3-0.05SrSnO3ceramics, representative of different phase transition behavior.Our results clearly evidences the stabilizing effect of SrSnO3 on the antiferroelectric phase by enhancing the degree of mesostructural order.In doing so, our method establishes a new platform for exploring the impact of disorder on the long-range strain heterogeneity within antiferroelectrics and other materials with modulated crystal structures.