Atomic-scale observation of strain-dependent reversible topotactic transition in La0.7Sr0.3MnOx films under an ultra-high vacuum environment

Hu，Kejun1; Zhang，Xinyu3; Chen，Pingfan1; Lin，Renju1; Zhu，Jinlong4; Huang，Zhen1,2; Du，Haifeng1,5; Song，Dongsheng1; Ge，Binghui1

2022-12-01

10.1016/j.mtphys.2022.100922

Materials Today Physics   Impact Factor & Quartile

2542-5293

2542-5293

Reversible topotactic phase transition between perovskite (PV) and oxygen-vacancy-ordered brownmillerite (BM) structures provides an effective platform for realizing the control of physical properties in complex transition metal oxides. However, such reversibility always requires extreme external conditions, that is, a high temperature and vacuum environment during the PV-BM transition, while an oxidizing atmosphere and relatively low temperature vice versa. Here, we experimentally observe the reversible process in strained LaSrMnO films at atomic scale by using in-situ heating aberration-corrected scanning transmission electron microscopy (STEM). Apart from the conventional reduction reaction of creating oxygen-vacancy-ordered frameworks after heating in the TEM, the inverse process of BM-to-PV transition is unexpectedly discovered under such an ultra-high vacuum atmosphere (∼10 Torr) at room temperature. Moreover, this abnormal behavior is strain-dependent. The large compressive strain is found to be detrimental to the inverse phase transition. The density functional theory (DFT) calculations show that the high oxygen affinity of LaSrMnO is responsible for the reversible transitions. Our findings provide a new insight into the redox reactions of manganite and might be further utilized for potential applications in solid fuel cells, oxygen sensors or resistive switching memories.

Brownmillerite In situ STEM Oxygen-vacancy-ordered Reversible topotactic phase transition

SCI

English

Others

National Natural Science Foundation of China[11874394];National Natural Science Foundation of China[12074001];National Natural Science Foundation of China[12104002];Natural Science Foundation of Anhui Province[2108085Y03];National Natural Science Foundation of China[52173215];

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied

WOS:000892365500001

ELSEVIER

2-s2.0-85142377413

Scopus

1.Information Materials and Intelligent Sensing Laboratory of Anhui Province,Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education,Institutes of Physical Science and Information Technology,Anhui University,Hefei,230601,China
2.Stony Brook Institute at Anhui University,Anhui University,Hefei,230039,China
3.Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen,518055,China
4.Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China
5.Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions,High Magnetic Field Laboratory,HFIPS,Chinese Academy of Sciences,Hefei,Anhui,230031,China

Hu，Kejun,Zhang，Xinyu,Chen，Pingfan,et al. Atomic-scale observation of strain-dependent reversible topotactic transition in La0.7Sr0.3MnOx films under an ultra-high vacuum environment[J]. Materials Today Physics,2022,29.

Hu，Kejun.,Zhang，Xinyu.,Chen，Pingfan.,Lin，Renju.,Zhu，Jinlong.,...&Ge，Binghui.(2022).Atomic-scale observation of strain-dependent reversible topotactic transition in La0.7Sr0.3MnOx films under an ultra-high vacuum environment.Materials Today Physics,29.

Hu，Kejun,et al."Atomic-scale observation of strain-dependent reversible topotactic transition in La0.7Sr0.3MnOx films under an ultra-high vacuum environment".Materials Today Physics 29(2022).