Unraveling potential phase transition mechanism of NBT-based systems: From an interesting view to survey ferroelectric loops

Abstract

As for assessing strain performances of Na0.5Bi0.5TiO3-based systems, the driving field level is a critical parameter. Currently, both current density and strain rate evaluation methods have been utilized to characterize the driving field. However, we find that some discrepancies indeed exist between these two evaluation methods, especially for the highly ergodic condition. By means of the typical ferroelectric theory, the initial analysis for discrepant current density and strain rate loops reveals that the relaxor-ferroelectric transition is likely to be a multi-step transition process. Dynamic dielectric loss/permittivity evolution further confirms the speculation and suggests that partial transition steps may be consisted of successive transition events. Ferroelectric and dielectric loops not only provide a fantastic view to unravel the multi-step relaxor-ferroelectric transition process, but also guides to regulate the strain appraisal system.