Professor Jiagang Wu’s research team of College of Material Science and Engineering has made important progress in the study of performance regulation and physical mechanism of potassium sodium niobate-based Lead-free Piezoelectric ceramics. This work, in cooperation with the National University of Singapore and Xi'an Jiaotong University, elaborates on the evolution process of multiphase coexistence. The team used nanoscale multiphase coexistence to construct Slush Polar State. And a new type of relaxation behavior at the ferroelectric phase transition is presented. The phase boundaries of these new relaxation properties further enhance the piezoelectric properties of potassium sodium niobate-based ceramics. The research findings are published in Journal of the American Chemical Society（ IF=14.695 ）in an article titled “Ultrahigh Performance in Lead-free Piezoceramics Utilizing a Relaxor Slush Polar State with Multiphase Coexistence”. The first author is the SCU doctoral student of Hong Tao. Professor Jiagang Wu is a corresponding author, and Sichuan University is the first work unit of this research paper. The research partners are the National University of Singapore and Xi’an Jiaotong University.

Figure 1: Title and Research Design

“Here we achieve a slush polar state with multiphase coexistence in lead-free potassium–sodium niobate ( KNN ) piezoceramics, which shows a novel relaxor behavior, i.e., frequency dispersion at the transition between different ferroelectric phases. This work demonstrates a new strategy for designing lead-free piezoelectrics with further enhanced performance, which should also be applicable to other functional materials requiring a slush ( flexible ) state with respect to external stimulus.” ( Abstract )

Being founded by American Chemical Society in 1879, Journal of the American Chemical Society（JACS）is one of the most influential periodicals in materials and chemistry. So far, JACS has published only five articles on the regulation of piezoelectric properties of Perovskite-type lead-free piezoelectric ceramics, and four of them are credited with this research team.

The research work has been funded by the Outstanding Youth Science Foundation ( 51722208) , among others.

Article link: https://pubs.acs.org/doi/abs/10.1021/jacs.9b07188