Metastable oxygen vacancy ordering state and improved memristive behavior in TiO2 crystals

Tianyu Li; Fang Hong; Ke Yang; Binbin Yue; Nobumichi Tamura; Hua Wu; Zhenxiang Cheng; Chunchang Wang

doi:10.1016/j.scib.2020.02.013

Metastable oxygen vacancy ordering state and improved memristive behavior in TiO₂ crystals

Sci Bull (Beijing). 2020 Apr 30;65(8):631-639. doi: 10.1016/j.scib.2020.02.013. Epub 2020 Feb 18.

Authors

Tianyu Li¹, Fang Hong², Ke Yang³, Binbin Yue², Nobumichi Tamura⁴, Hua Wu⁵, Zhenxiang Cheng⁶, Chunchang Wang⁷

Affiliations

¹ Laboratory of Dielectric Functional Materials, School of Physics & Material Science, Anhui University, Hefei 230601, China.
² Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Advanced Liight Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
³ Laboratory for Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China; Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
⁴ Advanced Liight Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁵ Laboratory for Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China; Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China. Electronic address: wuh@fudan.edu.cn.
⁶ Institute for Superconducting and Electronic Materials, University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia. Electronic address: cheng@uow.edu.au.
⁷ Laboratory of Dielectric Functional Materials, School of Physics & Material Science, Anhui University, Hefei 230601, China; State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. Electronic address: ccwang@ahu.edu.cn.

PMID: 36659132
DOI: 10.1016/j.scib.2020.02.013

Abstract

Oxygen vacancy is one of the pivotal factors for tuning/creating various oxide properties. Understanding the behavior of oxygen vacancies is of paramount importance. In this study, we identify a metastable oxygen vacancy ordering state other than the well-known Magnéli phases in TiO₂ crystals from both experimental and theoretical studies. The oxygen vacancy ordering is found to be a zigzag chain along the [0 0 1] direction in the (1 1 0) plane occurring in a wide temperature range of 200-500 °C. This metastable ordering state leads to a first-order phase transition accompanied by significant enhancement of dielectric permittivity and a memristive effect featuring a low driving electric field. Our results can improve oxide properties by engineering oxygen vacancies.

Keywords: Memristive effect; Oxygen vacancy ordering; Phase transition; TiO(2) single crystal.