Origin of the emergence of higher T c than bulk in iron chalcogenide thin films [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2017. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- Article numbers 9,994 : digital, PDF file
- Additional Creators:
- Brookhaven National Laboratory, United States. Department of Energy. Office of Basic Energy Sciences, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Fabrication of epitaxial FeSexTe1-x thin films using pulsed laser deposition (PLD) enables improving their superconducting transition temperature (Tc) by more than ~40% than their bulk Tc. Intriguingly, Tc enhancement in FeSexTe1-x thin films has been observed on various substrates and with different Se content, x. To date, various mechanisms for Tc enhancement have been reported, but they remain controversial in universally explaining the Tc improvement in the FeSexTe1-x films. In this report, we demonstrate that the controversies over the mechanism of Tc enhancement are due to the abnormal changes in the chalcogen ratio (Se:Te) during the film growth and that the previously reported Tc enhancement in FeSe0.5Te0.5 thin films is caused by a remarkable increase of Se content. Although our FeSexTe1-x thin films were fabricated via PLD using a Fe0.94Se0.45Te0.55 target, the precisely measured composition indicates a Se-rich FeSexTe1-x (0.6 < x < 0.8) as ascertained through accurate compositional analysis by both wavelength dispersive spectroscopy (WDS) and Rutherford backscattering spectrometry (RBS). We suggest that the origin of the abnormal composition change is the difference in the thermodynamic properties of ternary FeSexTe1-x, based on first principle calculations.
- Published through SciTech Connect., 08/30/2017., "bnl--114442-2017-ja", "KC0201060", Scientific Reports 7 1 ISSN 2045-2322 AM, Sehun Seo; Jong-Hoon Kang; Myeong Jun Oh; Il-Seok Jeong; Jianyi Jiang; Genda Gu; Jung-Woo Lee; Jongmin Lee; Heesung Noh; Mengchao Liu; Peng Gao; Eric E. Hellstrom; Joo-Hyoung Lee; Youn Jung Jo; Chang-Beom Eom; Sanghan Lee., and National Research Foundation of Korea (NRF)
- Funding Information:
- SC0012704, FG02-06ER46327, and PO010
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