Ferroelectricity and Self-Polarization in Ultrathin Relaxor Ferroelectric Films

Peixian Miao; Yonggang Zhao; Nengneng Luo; Diyang Zhao; Aitian Chen; Zhong Sun; Meiqi Guo; Meihong Zhu; Huiyun Zhang; Qiang Li

doi:10.1038/srep19965

Ferroelectricity and Self-Polarization in Ultrathin Relaxor Ferroelectric Films

Sci Rep. 2016 Jan 28:6:19965. doi: 10.1038/srep19965.

Authors

Peixian Miao^{1

2}, Yonggang Zhao^{1

2}, Nengneng Luo³, Diyang Zhao^{1

2}, Aitian Chen^{1

2}, Zhong Sun^{1

2}, Meiqi Guo^{1

2}, Meihong Zhu^{1

2}, Huiyun Zhang^{1

2}, Qiang Li³

Affiliations

¹ Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
² Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
³ Department of Chemistry, Tsinghua University, Beijing 100084, China.

Abstract

We report ferroelectricity and self-polarization in the (001) oriented ultrathin relaxor ferroelectric PMN-PT films grown on Nb-SrTiO3, SrRuO3 and La0.7Sr0.3MnO3, respectively. Resistance-voltage measurements and AC impedance analysis suggest that at high temperatures Schottky depletion width in a 4 nm thick PMN-PT film deposited on Nb-SrTiO3 is smaller than the film thickness. We propose that Schottky interfacial dipoles make the dipoles of the nanometer-sized polar nanoregions (PNRs) in PMN-PT films grown on Nb-SrTiO3 point downward at high temperatures and lead to the self-polarization at room temperature with the assistance of in-plane compressive strain. This work sheds light on the understanding of epitaxial strain effects on relaxor ferroelectric films and self-polarization mechanism.

Publication types

Research Support, Non-U.S. Gov't