Piezoelectric Aging Behavior of Lead-free 1-mol％ Li2O-excess 0.9(Na0.52K0.48)NbO3-0.1LiTaO3 Multilayer Ceramic Actuators
One-mol％ Li2O excess 0.9(Nao.52Ko.48)Nb03-0.1LiTaO3 lead-free piezoelectric multilayer ceramic actuators were investigated to determine their aging properties. To reduce the thermal aging behavior, we applied a rectified unipolar electric field of 5 kV/mm to the specimen to accelerate the electric aging behavior. By employing a rectified unipolar electric field for the piezoelectric actuators, we could remove undesirable heating from the relaxation current in the motion of the ferroelectric domain. To accelerate the aging test, the applied electric fields had a frequency of 900 Hz. To have enough time for charging and discharging, we employed an accurate time constant to design the equivalent circuit model for the aging tester. To extract exact aging behavior, we measured the pseudo-piezoelectric coefficient before and after the aging process. We also measured the electro-mechanical coupling coefficient, the frequency-dependent dielectric permittivity, and the impedance to compare with fresh and aged specimen.
Lead-free piezoelectric Ferroelectrics
Seok-Woo YUN Kyung-Su Lee Song-Min Nam Jung-Hyuk Koh
Department of Electronic Materials engineering, Kwangwoon University, Seoul 139-701, Korea Soon-Jong Jeong and Min-Soo KlM Korea Electrotechnology Research Institute, Changwon 642-120, Korea
国际会议
首尔
英文
590-593
2010-02-07（万方平台首次上网日期，不代表论文的发表时间）