Self-organized ferroelastic superdomains with enhanced piezoresponse in (101)-oriented Pb(Zr0.2,Ti0.8)O3 thin film
Yu-Chen Liu1*, Meng-Xun Xie1, Yu-Huai Li1, Sheng-Zhu Ho1, Chin-Han Huang2, Min-Yuan Huang2, Chun-Wei Huang3, Yi Chou4, Chih-Yen Chen5, Yi-Chia Chou4, Yi-Chun Chen1,6, Heng-Jui Liu2, Jan-Chi Yang1,6
1Department of Physics, National Cheng Kung University, Tainan, Taiwan
2Department of Materials Science and Engineering, National Chung Hsing University, Taichung, Taiwan
3Material and Chemical Research Laboratories, Nanotechnology Research Center, Industrial Technology Research Institute, Hsinchu, Taiwan
4Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
5Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung, Taiwan
6Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, Taiwan
* Presenter:Yu-Chen Liu,
Through the prorper control of crystalline orientation, strain, thickness and defect density in the thin films, thin film engeering has provided large amounts of degrees of freedom in modifing the physical properties, phase stability and domain architectures of functional materials.
In this study, we controlled the thickness of thin film to provide specific strain in Pb(Zr, Ti)O3 thin films which were grown on (110)-oriented SrTiO3 (STO) substrates and revealed a naturally formed superdomain structure appearing in the (101)-oriented tetragonal Pb(Zr,Ti)O3 epitaxial heterostructure. Different from typical a/c domains, these superdomains are composed of (101)-oriented domains with alternative arrangement of opposite out-of-plane polarizations and have 90o domain walls in between the conjunction. It is another type of 90o domain wall that can exist in the low symmetric preferred crystalline orientation. Furthermore, the superdomains present an atypical piezoresponse hysteresis loop with additional intermediate states, corresponding to the switching process of multistate ferroelastic domains.
This work gives a new perspective of the correlation between domain pattern, lattice symmetry, and polarity switching and suggests that not only the typical a/c domain transition but also the elastic deformation of these tiny superdomains can serve as key tunabilities of complex domain engineering.

Keywords: Ferroelectric, Superdomain, PZT, Pulsed laser deposition, Scanning probe microscopy