The novel electrical properties in quasi-2D hybrid improper ferroelectric Sr₃Sn₂O₇ ceramic and the structural modulation

The quasi-two-dimensional Ruddlesden-Popper material, Sr3Sn2O7 with hybrid improper ferroelectricity, has gained significant scientific interest owing to its unique ferroelectric phase transition mechanism. However, its electrical behaviors near the phase transition temperature necessitate further investigation. In this study, high-quality Sr3Sn2O7 ceramic was successfully prepared, and its temperature-dependent electrical properties were systematically studied. The phase transition from ferroelectric to paraelectric of Sr3Sn2O7 ceramic near 160? was evidenced by the varying electrical properties dependence of temperature. It is found that the space-charge-limited bulk conduction with deep traps is identified as dominant conduction mechanism for Sr3Sn2O7 ceramic that has high resistivity. An abnormal increasing trend of coercive field with temperature was observed and is discussed with trap-filling process and octahedral rotation distortion. Interestingly, Sr3Sn2O7 ceramic exhibits negative piezoelectric effect and negative electrostriction responded to biased electric field, which is dramatically influenced by ferroelectric polarization. Overall, this study serves as a reference for exploring the electrical properties of other hybrid improper ferroelectrics, particularly near their Curie temperature.