Abstract
We investigate A-site cation ordering in the ferroelectric perovskite Bi0.5Na0.5TiO3 (BNT) by synchrotron X-ray total scattering. Although BNT has a problem of low depolarization temperature, it is a promising lead-free piezoelectric material. Since the depolarization temperature is presumed to correspond to a relaxor-like gradual order–disorder phase transition, local structural analysis is necessary to understand the structure of the disorder phase. Using this approach, we reveal the elusive connection between chemical and structural heterogeneity. The short-range order structure largely deviates from the rhombohedral average structure due to the off-center shift of Ti with large randomness. Consequently, the Ti off-center shift is averaged out beyond the unit cell and the structure becomes identical to the average structure beyond the unit cell. We further locate nanoscale regions of monoclinic distortion due to the heterogeneity of the A-site ion composition. The change in the short-range-order structure with distance can determine the BNT depolarization temperature. The results show necessary models to develop next generation novel piezoelectric materials.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
