Technological Sciences
Fei Li
Fei Li, born in Xi'an, Shaanxi Province, 1983, is currently a professor at the school of Electronic Science and Engineering of Xi'an Jiaotong University. He received a Bachelor’s degree from Xi'an Jiaotong University in 2006 and a Doctorate degree from the same University in 2012. Since then, he joined in Electronic Materials Research Lab in Xi’an Jiaotong University as a lecturer during July 2012-Marth 2015; and an associate professor during April 2015- Sep. 2018. From Oct 2015 to Jun 2018, he worked as a postdoctoral researcher and research associate in Materials Research Institute of the Pennsylvania State University, co-supervised by Profs. Long-Qing Chen and Thomas R. Shrout. He is now an associate editor of IEEE Transactions on Ultrasonics, ferroelectrics, and frequency control and an editorial board member of Journal of the Chinese Ceramic Society.
His research mainly focuses on ferroelectric materials and devices. He has achieved a series of innovative research results with international influence, in understanding the ultrahigh piezoelectricity in relaxor ferroelectric crystals, developing high-performance piezoelectric materials, designing and fabrication of transparent ferroelectric crystals with ultrahigh piezoelectricity. His work was selected as “The Top Ten Scientific Advances in China (2020)” by Ministry of Science and Technology of China. He received IEEE Ferroelectrics Young Investigator Award (2020), the American Ceramic Society’s Ross Coffin Purdy Award (2020) and the Second Prize of National Natural Science Award of China (2015, 5/5).
Exploration of the mechanisms enabling high performance in relaxor ferroelectric crystals
Relaxor ferroelectric single crystals, which possess excellent dielectric, piezoelectric, electro-optic and pyroelectric properties, are important functional dielectric materials in the field of electronic science and technology. There is a significant demand for such high performance materials for medical ultrasonic diagnosis, underwater acoustic detection, precision driving, electro-optic technologies, etc. However, since the discovery of relaxor ferroelectric crystals for more than 20 years, the origin of the outstanding properties has not been solved, which hinders the further improvement of the dielectric and piezoelectric properties of these crystals, thus cannot meet the ever-increasing requirements of multifunction, miniaturization and high sensitivity in advanced electronic devices. To address above issues, Fei Li has systematically studied the structure-property relationship of the relaxor ferroelectric crystals, established the phase-field model and accurately simulated the electromechanical properties, by which clarified the underlying mesoscale mechanism responsible for the ultrahigh piezoelectricity in relaxor ferroelectric crystals. On this basis, Fei Li designed and fabricated a series of novel high-performance relaxor ferroelectric crystals, crystal-polymer composites and textured ceramics by judiciously introducing local structure heterogeneity and engineering the long-range ferroelectric domain structure. Some of these materials have been utilized in the R&D of next-generation underwater acoustic transducers, medical ultrasonic transducers, photoacoustic imaging transducers and electro-optic modulators, achieved a substantial improvement in the key performance indicators of the devices, and promoted the miniaturization, portability and low power consumption of these devices.