header

Atomic-Scale Insight into the Reversibility of Polar Order in Ultrathin Epitaxial Nb:SrTiO 3/BaTiO 3 Heterostructure and Its Implication to Resistive Switching

22 Pages Posted: 30 Oct 2019 First Look: Accepted

See all articles by Junxiang Yao

Junxiang Yao

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Mao Ye

Southern University of Science and Technology - Department of Physics

Yuanwei Sun

Peking University - International Center for Quantum Materials

Ye Yuan

East China Normal University (ECNU) - Key Laboratory of Polar Materials and Devices

Hua Fan

South University of Science and Technology of China - Department of Physics

Yuan Zhang

Xiangtan University - School of Materials Science and Engineering

Chao Chen

South China Normal University, Academy of Advanced Optoelectronics, Institute for Advanced Materials

Cong Liu

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Ke Qu

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Gaokuo Zhong

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Tingting Jia

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Zhen Fan

South China Normal University, Academy of Advanced Optoelectronics, Institute for Advanced Materials; South China Normal University, Academy of Advanced Optoelectronics, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology

Shanming Ke

Nanchang University - School of Materials Science and Engineering

Yue Zhao

South University of Science and Technology of China - Department of Physics

Chungang Duan

East China Normal University (ECNU) - Key Laboratory of Polar Materials and Devices

Peng Gao

Peking University - Electron Microscopy Laboratory; Peking University - International Center for Quantum Materials; Peking University - Academy for Advanced Interdisciplinary Studies; Collaborative Innovation Centre of Quantum Matter

Jiangyu Li

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

Abstract

Ferroelectric heterostructures with bi-stable state of polarization are appealing for data storage as well as tunable functionalities such as memristor behavior. While an increasing number of experimental and theoretical studies suggest that polarization persists in ultrathin epitaxial heterostructures approaching just a couple of unit cells, the switching of such polar order is much less well understood, and whether polarization can be reversed in ultrathin ferroelectric heterostructures remains to be answered. Here we fabricate high-quality 7-unit cell thick BaTiO3 (BTO) films on Nb-doped single crystalline SrTiO3 (NSTO) substrate, and demonstrate their apparent yet unambiguously false polarization reversal due to charge injection using comprehensive piezoresponse force microscopy (PFM) studies. The presence of weak polar order consistent with linear piezoelectricity is confirmed at the atomic scale by high resolution integrated differential phase contrast (IDPC) of transmission electron microscopy (TEM) as well as macroscopic second harmonic generation (SHG), while the lack of polarization reversal under the voltage applied is supported by density functional theory calculation showing the persistence of dead layer on the surface. Nevertheless, poling-induced electric conduction differing by two orders of magnitude is observed, demonstrating resistive switching in ferroelectric heterostructure in the absence of polarization reversal, even with weak polar order. Our finding has technological implications on emerging memristor applications with potentially more accessible states than bi-stable polarization modulated mechanism, and raises technical challenges to unambiguously demonstrate polarization switching in ultrathin films at their critical size limit.

Keywords: Ultrathin epitaxial ferroelectric semiconductor heterostructures, BaTiO3/Nb:SrTiO3, resistive switching, piezoresponse force microscopy, atomic-scale polar order of ferroelectricity

Suggested Citation

Yao, Junxiang and Ye, Mao and Sun, Yuanwei and Yuan, Ye and Fan, Hua and Zhang, Yuan and Chen, Chao and Liu, Cong and Qu, Ke and Zhong, Gaokuo and Jia, Tingting and Fan, Zhen and Ke, Shanming and Zhao, Yue and Duan, Chungang and Gao, Peng and Li, Jiangyu, Atomic-Scale Insight into the Reversibility of Polar Order in Ultrathin Epitaxial Nb:SrTiO 3/BaTiO 3 Heterostructure and Its Implication to Resistive Switching (October 23, 2019). Available at SSRN: https://ssrn.com/abstract=3474533

Junxiang Yao

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Mao Ye

Southern University of Science and Technology - Department of Physics

Guangdong
China

Yuanwei Sun

Peking University - International Center for Quantum Materials

Beijing, 100871
China

Ye Yuan

East China Normal University (ECNU) - Key Laboratory of Polar Materials and Devices

China

Hua Fan

South University of Science and Technology of China - Department of Physics

Shenzhen, 518055
China

Yuan Zhang

Xiangtan University - School of Materials Science and Engineering

China

Chao Chen

South China Normal University, Academy of Advanced Optoelectronics, Institute for Advanced Materials

Guangzhou
China

Cong Liu

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Ke Qu

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Gaokuo Zhong

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Tingting Jia

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Zhen Fan

South China Normal University, Academy of Advanced Optoelectronics, Institute for Advanced Materials

Guangzhou
China

South China Normal University, Academy of Advanced Optoelectronics, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology

Guangzhou
China

Shanming Ke

Nanchang University - School of Materials Science and Engineering

China

Yue Zhao

South University of Science and Technology of China - Department of Physics

Shenzhen, 518055
China

Chungang Duan

East China Normal University (ECNU) - Key Laboratory of Polar Materials and Devices

China

Peng Gao

Peking University - Electron Microscopy Laboratory ( email )

Beijing, 100871
China

Peking University - International Center for Quantum Materials ( email )

Beijing, 100871
China

Peking University - Academy for Advanced Interdisciplinary Studies ( email )

Beijing, 100871
China

Collaborative Innovation Centre of Quantum Matter ( email )

Beijing, 100871
China

Jiangyu Li (Contact Author)

Chinese Academy of Sciences (CAS) - Shenzhen Key Laboratory of Nanobiomechanics ( email )

1068 Xueyuan Avenue
Shenzhen University Town
Shenzhen
China

Here is the Coronavirus
related research on SSRN

Paper statistics

Abstract Views
165
Downloads
44