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Li M, Chen P, Zhang Y, Zhang Y, Liu Z, Tang C, Chung JY, Gu M, Li J, Huang Z, Chow GM, Li C, Pennycook SJ. Atomic Origins of Enhanced Ferroelectricity in Nanocolumnar PbTiO 3 /PbO Composite Thin Films. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2203201. [PMID: 36593529 DOI: 10.1002/smll.202203201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Nanocomposite films hold great promise for multifunctional devices by integrating different functionalities within a single film. The microstructure of the precipitate/secondary phase is an essential element in designing composites' properties. The interphase strain between the matrix and secondary phase is responsible for strain-mediated functionalities, such as magnetoelectric coupling and ferroelectricity. However, a quantitative microstructure-dependent interphase strain characterization has been scarcely studied. Here, it is demonstrated that the PbTiO3 (PTO)/PbO composite system can be prepared in nano-spherical and nanocolumnar configurations by tuning the misfit strain, confirmed by a three-dimensional reconstructive microscopy technique. With the atomic resolution quantitative microscopy with a depth resolution of a few nanometers, it is discovered that the strained region in PTO is much larger and more uniform in nanocolumnar compared to nano-spherical composites, resulting in much enhanced ferroelectric properties. The interphase strain between PbO and PTO in the nanocolumnar structure leads to a giant c/a ratio of 1.20 (bulk value of 1.06), accompanied by a Ti polarization displacement of 0.48 Å and an effective ferroelectric polarization of 241.7 µC cm-2 , three times compared to the bulk value. The quantitative atomic-scale strain and polarization analysis on the interphase strain provides an important guideline for designing ferroelectric nanocomposites.
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Affiliation(s)
- Mengsha Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada
| | - Pingfan Chen
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Yingli Zhang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
- Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Yuan Zhang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
- Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Zhenghao Liu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
- Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Chunhua Tang
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Jing Yang Chung
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Mingqiang Gu
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Junxue Li
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Zhen Huang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
- Stony Brook Institute at Anhui University, Anhui University, Hefei, Anhui, 230039, China
| | - Gan Moog Chow
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Changjian Li
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
- Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
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Li M, Qiu C, Dogel S, Chen P, Perovic DD, Howe JY. Microstructure-Dependent Thermal Stability of Super-Tetragonal Nanocomposite Films through In Situ TEM/EELS Study. ACS APPLIED MATERIALS & INTERFACES 2022; 14:52316-52323. [PMID: 36351083 DOI: 10.1021/acsami.2c16084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Smart microstructure design in nanocomposite films allows us to tailor physical properties such as ferroelectricity and thermal stability to broaden applications of next-generation electronic devices. Here, we study the thermal stability of self-assembled PbTiO3 (PTO)/PbO nanocomposite films with nano-spherical and nanocolumnar microstructures by utilizing an environmental transmission electron microscopy (TEM) combined with electron energy loss spectroscopy (EELS). The real-time study reveals that the microstructure-dependent interphase strain has an effect on the stabilization of the tetragonal phase. Compared to the nano-spherical configuration, the nanocomposite film with the nanocolumnar microstructure can maintain the giant tetragonality of ∼1.20 up to 450 °C, and the tetragonal phase is predicted to be stable at elevated temperatures > 600 °C. Moreover, the temperature-dependent EELS further demonstrates the sensitivity of the chemical bonding of Pb and Ti with O to the PTO lattice distortion, correlating the structural variation and electronic properties at different temperatures. Such in situ heating TEM study provides insights into the thermal stability of nanocomposites with different microstructures and facilitates the advancement of power electronics applications in harsh environments.
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Affiliation(s)
- Mengsha Li
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S 3E4, Canada
| | - Chenyue Qiu
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S 3E4, Canada
| | - Stas Dogel
- Hitachi High Tech Canada Inc., Etobicoke, Ontario M9W 6A4, Canada
| | - Pingfan Chen
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, Anhui, China
| | - Doug D Perovic
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S 3E4, Canada
| | - Jane Y Howe
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S 3E4, Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
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