Ferroelectric Oxide Thin Film with an Out-of-Plane Electrical Conductivity

Tingting Yao; Yixiao Jiang; Chunlin Chen; Xuexi Yan; Ang Tao; Lixin Yang; Cuihong Li; Kenyu Sugo; Hiromichi Ohta; Hengqiang Ye; Yuichi Ikuhara; Xiuliang Ma

doi:10.1021/acs.nanolett.9b04210

Ferroelectric Oxide Thin Film with an Out-of-Plane Electrical Conductivity

Nano Lett. 2020 Feb 12;20(2):1047-1053. doi: 10.1021/acs.nanolett.9b04210. Epub 2019 Dec 30.

Authors

Tingting Yao¹, Yixiao Jiang¹, Chunlin Chen¹, Xuexi Yan¹, Ang Tao¹, Lixin Yang¹, Cuihong Li¹, Kenyu Sugo², Hiromichi Ohta², Hengqiang Ye¹, Yuichi Ikuhara^{3

4

5}, Xiuliang Ma¹

Affiliations

¹ Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , China.
² Research Institute for Electronic Science , Hokkaido University , N20W10, Kita, Sapporo 001-0020 , Japan.
³ Advanced Institute for Materials Research , Tohoku University , 2-1-1 Katahira , Aoba-ku, Sendai 980-8577 , Japan.
⁴ Institute of Engineering Innovation , The University of Tokyo , 2-11-16 Yayoi , Bunkyo-ku, Tokyo 113-8656 , Japan.
⁵ Nanostructures Research Laboratory , Japan Fine Ceramics Center , 2-4-1 Mutsuno , Atsuta, Nagoya 456-8587 , Japan.

PMID: 31877055
DOI: 10.1021/acs.nanolett.9b04210

Abstract

Ferroelectricity and electrical conductivity are two fundamentally incompatible properties that are difficult to simultaneously achieve in a material. Here, we combine these two contradictory properties by embedding conducting SrNbO₃ micro/nanopillars into a ferroelectric SrNbO_3.5 (i.e., Sr₂Nb₂O₇) thin film. The high-T_c ferroelectric SrNbO_3.5 thin film is epitaxially grown on a LaAlO₃ substrate by pulsed laser deposition. The conducting SrNbO₃ micro/nanopillars are introduced into the film via an electron-irradiation-induced SrNbO_3.5-to-SrNbO₃ phase transformation triggered by a focused electron beam. The sizes and distribution of the SrNbO₃ micro/nanopillars can be accurately controlled through artificial manipulation of the electron-irradiation-induced SrNbO_3.5-to-SrNbO₃ phase transformation. The ferroelectric SrNbO₃/SrNbO_3.5 thin film with an in-plane polarization exhibits an electrical conductivity in the out-of-plane direction. Such conducting ferroelectric thin films may lead to the discovery of plentiful physical phenomena and have great potential for pyroelectric, photoelectric, and multiferroic applications.

Keywords: Ferroelectric materials; electron irradiation; one-dimensional conductivity; phase transformation; transmission electron microscopy.