Ferroelectric and dielectric behaviors of sol-gel derived perovskite PMN-PT/PZT heterostructures via compositional development: An interface-dependent study

Phase-pure perovskite 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3/Pb(Zr0.52Ti0.48)O3 (PMN-PT/PZT) heterostructures were prepared via compositional development using a sol-gel route. Interface-dependent microstructure, insulating, ferroelectric and dielectric performance were investigated. Relatively enhanced ferroelectricity (Pr = 21.81 μC/cm2, Ec = 61.88 kV/cm) and dielectricity (εr = 1959, tanδ = 0.0152) were obtained for the heterostructure with the maximum number of interfaces (7 interfaces, namely F-7 type). Presumably, this behavior is due to the reduced leakage current density (10−9-10−8 A/cm2 at ±400 kV/cm), which arises from columnar grain growth mode with more depletion layers generated between different compositions acting as a potential barrier for the movement of free carriers. A simplified equivalent circuit is used to provide a comprehensive explanation of the enhanced performance mechanism. These results highlight inherent issues in designing structures with specific interfaces and provide a new approach for designing high-performance PMN-PT-based thin film.