Disordered ferroelectricity in the PbTiO3/SrTiO3 superlattice thin film
Gi-Yeop Kim,
Kanghyun Chu,
Kil-Dong Sung,
Hak-Sung Lee,
Sung-Dae Kim,
Kyung Song,
Taekjib Choi,
Jaichan Lee,
James P. Buban,
Seog-Young Yoon,
Kwang-Ho Kim,
Chan-Ho Yang,
Si-Young Choi
Affiliations
Gi-Yeop Kim
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Kanghyun Chu
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
Kil-Dong Sung
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Hak-Sung Lee
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Sung-Dae Kim
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Kyung Song
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Taekjib Choi
Hybrid Materials Research Center and Faculty/Institute of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, South Korea
Jaichan Lee
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, South Korea
James P. Buban
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
Seog-Young Yoon
School of Materials Science and Engineering, Pusan National University, Pusan 46241, South Korea
Kwang-Ho Kim
School of Materials Science and Engineering, Pusan National University, Pusan 46241, South Korea
Chan-Ho Yang
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
Si-Young Choi
Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 51508, South Korea
The PbTiO3/SrTiO3 superlattice thin films with a low volume fraction of PbTiO3 have not attracted much interest because they are thought to exhibit only a paraelectric state. In this study, we focus on a superlattice thin film with thin PbTiO3 (PTO) and thick SrTiO3 (STO) layers, wherein the hidden ferroelectricity in the thin PbTiO3 layer is revealed. Atomic scale imaging analysis and electron energy loss spectroscopy reveal the existence of a disordered ferroelectric polarization state without innate tetragonal distortion in the (6PTO/15STO)5 superlattice. The piezoelectric force microscopy analysis confirms that this disordered ferroelectricity can enhance piezoelectric response.
