Antiferroelectricity of NaNbO₃: Single‐crystal experimental study and first‐principles calculation

Abstract

Similar to the canonical antiferroelectric (AFE) compound PbZrO3 in Pb(Zr,Ti)O3 solid‐solutions, the presence of double hysteresis loops and that of electric field–induced phase transitions are important characteristics of NaNbO3 AFE materials; yet the phase transition behavior in the latter system is typically irreversible with the related mechanisms not fully understood. Here, we explore the phase transition mechanism of ferroelectric and AFE phases in NaNbO3 based on measurements of single crystals with different directions in conjunction with density‐functional theory (DFT) calculations. The tilting and distortion behaviors of the [NbO6] octahedra are explained by DFT, and the ion displacement in the lattice is traced. The tilting and distortion behaviors of the [NbO6] octahedra with different orientations are compared. We confirm that the tilt and distortion of the [NbO6] octahedra along the [1 1 1] direction is the main reason to improve the stability of AFE phase. This conclusion is verified by the experimental characterizations of large‐size NaNbO3 single crystals successfully obtained in this study.

Multistep synergistic modified NaNbO3-based ceramics for high-performance electrostatic capacitors

“…9,16,17 NN ceramics are AFE P phase at room temperature, but the free energy difference between this phase and the electric field-induced FE Q phase is very small. 18 Consequently, under high electric fields, NN irreversibly transforms into a metastable FE Q phase, making it challenging to achieve a well-defined AFE double hysteresis loop at room temperature, which limits the improvement of the energy storage performance of NN ceramics. 19–21 To address this issue, numerous attempts have been made to optimize the energy storage performance of NN ceramics.…”

Utilizing Domain Engineering to Achieve High-Polarization Relaxor Ferroelectrics for Low-Consumption Ceramic Capacitors

“…However, during the transition from ferroelectric (FE) to antiferroelectric (AFE) behavior, polarization typically decreases . One strategy to mitigate this issue is inducing antiferroelectricity by incorporating NaNbO 3 (NN), which results in higher polarization characterized by double hysteresis ( P – E ) loops, as demonstrated in previous studies. , The antiferroelectricity of NN originates from the tilting of the [NbO 6 ] octahedra, a consequence of Nb–O hybridization . In this study, we integrated NaNbO 3 (NN) into the Ba 0.85 Ca 0.15 Zr 0.90 Ti 0.10 O 3 (BCZT) lattice.…”

“…16,17 The antiferroelectricity of NN originates from the tilting of the [NbO 6 ] octahedra, a consequence of Nb−O hybridization. 18 In this study, we integrated NaNbO All ceramics exhibit a perovskite structure without any impurities. As reported in previous studies, the Na and Nb atoms occupy the A-site and B-site of the BCZT lattice, respectively.…”

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

“…Among the few known lead-free AFE compounds, NaNbO 3 (NN) serves as a prime example of how structural heterogeneity affects the AFE-FE transition and, ultimately, its energy storage potential. , This is particularly due to its complex sequence of temperature-driven phase transitions, grain-size-induced phase transitions, and room temperature polymorphic instability . Furthermore, only NN single crystals have demonstrated reversible AFE-FE transitions at room temperature, which are highly dependent on the crystallographic orientation . All these factors pose major challenges on the practical design of AFE NN, by favoring the nonreversible transition to the FE state and thus lowering the recoverable energy density.…”