Local Phase Structure Evolution and Ferroelectric Response in Novel Bi-Layered Structure Relaxor Babi2ta2o9 Ceramic

Abstract

It is of importance to discover new type ferroelectric materials with enhanced functionalities to meet various demand of applications, here we prepared the BaBi2Ta2O9 ceramic with orthogonal structure and oxygen octahedral rotation. This type of material had been screened out to be a candidate ferroelectric before, 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 via 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.

Keywords: Pseudo-tetragonal structure, Polar nanoregions, Relaxor, ferroelectrics