Topotactic fluorination induced stable structure and tunable electronic transport in perovskite barium ferrite thin films. Issue 7 (May 2020)

• Record Type: Journal Article
• Authors: Li, Junjie; Huang, Haoliang; Qiu, Peiqi; Liao, Zhaolong; Zeng, Xierong; Lu, Yalin; Huang, Chuanwei
• Is Part Of: Ceramics international. Volume 46:Issue 7(2020)
• Page Start: 8761
• Page End: 8765
• Publication Date: 2020-05
• Subjects: Perovskites -- Oxide films -- Anionic doping; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.12.115
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The synthesis of perovskite (ABO3 ) films with mixed anions has enabled us to constitute a novel class of materials exhibiting intriguing functionalities. In contrast to traditional metallic cation doping, anion doping within easy-to-prepare conditions usually gives rise to tremendous modulations of physical properties with tunable crystal structures. Here, oxyfluoride BaFeO3-x Fy (BFO–F) thin films were successfully synthesized via a low-temperature reaction with polyvinylidene fluoride, which exhibit extremely structural stability over time. The existence of fluorine was confirmed by the combination of X-ray photoelectron depth profile and soft X-ray absorption spectroscopy. The oxyfluoride BFO–F films demonstrate a sequence of structural evolutions with reduced out-of-plane lattices, by means of elevating fluorination temperatures. The valence state of iron in BFO–F is gradually changed from 3 + to 4 + for higher fluorination temperatures. Moreover, the resistivity of BFO–F dramatically decreases, compared to that of pristine oxygen-deficient BaFeO3-δ film. Our results provide insight into the modulations on the structures and physical properties of perovskite oxyfluorides through the facile fluorination process and contribute to the fundamental understanding of fluorination.