CURRENT STATUS AND FUTURE PROSPECTS OF HIGH PERFORMANCE PIEZOELECTRIC SINGLE CRYSTALS: (LEAD-BASED AND LEAD-FREE BASED)
Prof. Ho-Yong Lee, Department of Materials Science and Engineering, Sunmoon University
October 6, 2015, 10:00 am, NIA, Rm 101
Abstract:
Crystallographically engineered Relaxor-PT single crystals, specifically PMN-PT and PZN-PT, offer much higher piezoelectric and electromechanical coupling coefficients (d33 > 1,500 pC/N, k33 > 0.9), when compared to PZT ceramics. Therefore, the high performance piezoelectric single crystals have been expected to replace polycrystalline PZT ceramics in many application fields such as ultrasound transducers (medical and NDA), SONAR transducer, piezoelectric actuators, piezoelectric sensors, ultrasonic motors and piezoelectric energy harvesting, etc. Recently the solid-state single crystal growth (SSCG) technique for fabricating the high performance “lead(Pb)-based” piezoelectric single crystals such as PMN-PT and PMN-PZT has been developed. Since the SSCG process is quite simple and similar to conventional sintering process, compared to conventional single crystal growth methods such as flux and Bridgman methods, it is very cost-effective and suitable to mass production. And recently the SSCG method was successfully applied to growth of “lead(Pb)-free” piezoelectric single crystals of high electromechanical coupling coefficients (k33 > 0.85). In this presentation the recent progress on development and application of “lead-based” and “lead-free” piezoelectric single crystals will be introduced.
Bio:
Ho-Yong Lee is a Professor in the Department of Materials Science and Engineering at Sunmoon University. He received a B.E. degree in Mineralogy and Petroleum from Seoul National University in 1987. From March 1987 to February 1993 he studied at Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea, and received his M.S. and Ph.D. in Materials Science and Engineering in 1989 and 1993, respectively. He developed the “Solid-state Single Crystal Growth (SSCG) technique” for ferroelectric/piezoelectric materials such as BaTiO3, Ba(Ti,Zr)O3, PMN-PT, and PMN-PZT. He also contributed to the understanding of the single crystal growth mechanism in the SSCG process. In 2000, he founded a venture company (Ceracomp Co., Ltd.) to commercialize the SSCG technique. His research interests focus on the fabrication, characterization, and application of ferroelectric/piezoelectric single crystals.