High performance electro-mechanical coupling devices are often related to the outstanding properties of relaxor ferroelectrics [1]. However, the exact mechanism of electro-mechanical coupling in this class of material is still not clarified. Even though numerous contributing effects have already been discovered, many of these effects and their interactions are not well understood and have nurtured controversial discussion. One of the most discussed topics in this field is the dynamic polarization behavior of relaxor ferroelectrics and its contribution to electro-mechanical coupling.
In the past 20 years, the understanding of electro-mechanical coupling mechanism has been greatly advanced by analyzing the dynamic dielectric response in ferroelectrics and relaxor ferroelectrics [2]. Recently, 50 – 80 % of the room temperature dielectric and piezoelectric responses of relaxor ferroelectrics were attributed to the presence of polar nanoregions by comparing properties at room and cryogenic temperatures [3].
In this approach, both methods were combined. The dynamic dielectric response of unpoled and poled single crystals and ceramics was investigated in the temperature range between 4 and 470 K. Amplitude and phase angle of the first and third harmonics of the relative dielectric permittivity were measured and analyzed with respect to driving field amplitude and frequency.
The obtained results clearly reveal different types of dynamic dielectric behavior in relaxor ferroelectrics between 4 and 470 K and elucidate their evolution with respect to driving field, frequency and temperature, contributing to the fundamental understanding of electro mechanical coupling.
References
[1] S. Zhang, F. Li, Journal of Applied Physics, 111, 031301 (2012)
[2] S. Hashemizadeh, D. Damjanovic, Applied Physics Letters, 110, 192905 (2017)
[3] F. Li, S. Zhang, T. Yang, Z. Xu, N. Zhang, G. Liu. J. Wang, J. Wang, Z. Cheng, Z.G. Ye, J. Luo, T.R. Shrout, L.Q. Chen, Nature communications, Nature Communications, 7:13807 (2016)
Ferroelectrics , Piezoelectrics , Advanced characterisation , Dielectric properties , Electrochemical behavior
