Abstract
Since the discovery of oxyfluoride cuprate superconductors, many efforts have been made to search for new transition-metal oxyfluoride compounds. Recently, the topotactic fluorination reaction using polyvinylidene fluoride (PVDF) has gained attention because of the low-temperature synthesis of oxyfluorides. In this study, we report the fabrication of SrCoOxFy epitaxial thin films via topotactic fluorination of SrCoO2.5 precursor films with PVDF. X-ray diffraction analysis showed that the SrCoOxFy film, with an anion-vacant perovskite structure, was obtained by fluorination at 150 °C and that the in-plane lattice constant was completely dependent on the substrate. Energy dispersive X-ray spectrometry revealed that the chemical composition of the fluorinated film was SrCoO1.9±0.4F0.5±0.1 and X-ray photoemission spectroscopy showed that the Co ions had a mixed valence state of 2+ and 3+. This valence state was smaller than that in the SrCoO2.5 precursor film, indicating that PVDF acted as a reductive fluorinating agent for the SrCoO2.5 film. Moreover, the SrCoO1.9±0.4F0.5±0.1 film did not exhibit ferromagnetism even at 10 K, suggesting the presence of an antiferromagnetic interaction between the Co ions.
Original language | English |
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Pages (from-to) | 527-530 |
Number of pages | 4 |
Journal | Journal of Sol-Gel Science and Technology |
Volume | 73 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2015 Jan 1 |
Externally published | Yes |
Keywords
- Epitaxial thin film
- Oxyfluorides
- Pulsed-laser deposition
- Topotactic reaction
- Transition-metal compounds
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Chemistry(all)
- Biomaterials
- Condensed Matter Physics
- Materials Chemistry