Local phase structure evolution and ferroelectric response in novel Bi-layered structure relaxor BaBi2Ta2O9 ceramic.

It is of importance to discover new type ferroelectric materials with enhanced functionalities to meet various demand of applications, here we prepared the BaBi 2 Ta 2 O 9 ceramic with orthogonal structure and oxygen octahedral rotation. This type of material had been screened out to be a candidate ferroelectric previously based on high-throughput first-principles density functional theory (DFT) calculations. The relationship between local phase structure and ferroelectric properties of this system is investigated by dielectric spectrum. Low-temperature relaxor behavior is described by using the Curie-Weiss law and the Vogel-Fulcher relationship. The polarization response and size of Polar nanoregions (PNRs) are described using the phenomenological statistical model. The P (E) loops imply that long-range-order ferroelectric is destroyed formation frozen randomly interacting PNRs. Element segregation and lattice distortion are directly observed using TEM, which is associated with the substitution of multiple atoms for the one cation occupation. • A novel Bi-layered structure ferroelectric BaBi2Ta2O9 screened out by high-throughput first-principles DFT was prepered. • BaBi2Ta2O9 is a ferroelectrric relaxor and shows an orthorhombic structural with space group Cmc21. • In situ Raman spectrotra enclosed a phase transition from non-centrosy symmetric phase to centrosy symmetric phase at 673K. • The size of PNRs of BaBi2Ta2O9 was determined by the phenomenological model and atomic scale morphological was observed by spherical aberration electron microscope. [ABSTRACT FROM AUTHOR]