Microstructure and physical properties of ε-Fe2O3 thin films fabricated by pulsed laser deposition

Shanshan Chen; Yixiao Jiang; Tingting Yao; Ang Tao; Xuexi Yan; Fang Liu; Chunlin Chen; Xiuliang Ma; Hengqiang Ye

doi:10.1016/j.micron.2022.103359

Microstructure and physical properties of ε-Fe₂O₃ thin films fabricated by pulsed laser deposition

Micron. 2022 Dec:163:103359. doi: 10.1016/j.micron.2022.103359. Epub 2022 Sep 29.

Authors

Shanshan Chen¹, Yixiao Jiang¹, Tingting Yao¹, Ang Tao¹, Xuexi Yan¹, Fang Liu², Chunlin Chen³, Xiuliang Ma⁴, Hengqiang Ye⁵

Affiliations

¹ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang 110016, China; Ji Hua Laboratory, Foshan 528200, China.
² Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang 110016, China.
³ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang 110016, China; Ji Hua Laboratory, Foshan 528200, China. Electronic address: clchen@imr.ac.cn.
⁴ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang 110016, China; State Key Lab of Advanced Processing and Recycling on Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China.
⁵ Ji Hua Laboratory, Foshan 528200, China.

PMID: 36201915
DOI: 10.1016/j.micron.2022.103359

Abstract

ε-Fe₂O₃ has attracted intense interest in the field of magnetoelectric materials due to its promising physical properties. The epitaxial growth of ε-Fe₂O₃ thin films is challenging since it is a metastable phase of iron oxide. In this study, ε-Fe₂O₃ (001) thin films are epitaxially grown on SrTiO₃ (111) substrates by pulsed laser deposition (PLD). The crystal structure, valence state, and microstructure of the ε-Fe₂O₃ thin films are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. It is revealed that the oxygen pressure, deposition and annealing temperatures, and laser beam energy affect significantly the epitaxial growth of ε-Fe₂O₃ thin films. The orientation relationship between films and substrates is ε-Fe₂O₃ (001)[010] // SrTiO₃ (111)[1¯10]. The magnetic hysteresis loops tested by a superconducting quantum interference device and UV-Vis reflection spectra suggest that the ε-Fe₂O₃ thin film with thickness of ∼ 20 nm has a strong magnetic anisotropy, a coercivity of 600 Oe, and an indirect band gap of 3.26 eV.

Keywords: Physical properties; Pulsed laser deposition; Thin film; Transmission electron microscopy; ε-Fe(2)O(3).