Observation of selective surface element substitution in FeTe<sub>0.5</sub>Se<sub>0.5</sub> superconductor thin film exposed to ambient air by synchrotron radiation spectroscopy

Observation of selective surface element substitution in FeTe_0.5Se_0.5 superconductor thin film exposed to ambient air by synchrotron radiation spectroscopy

Zhang Nian^{1, 2}, Liu Chen¹, Zhao Jia-Li¹, Lei Tao¹, Wang Jia-Ou¹, Qian Hai-Jie¹, Wu Rui¹, Yan Lei³, Guo Hai-Zhong³, Ibrahim Kurash^{1, †,}

Wide scan all element including PES results of the thin film shown from bottom to top in the order of the film being treated: as-grown, exposed to air, first time annealed at 350 °C for 30 min, etched for 10 min, etched for 20 min, etched for 30 min, and vacuum annealed again at 350 °C for 30 min before being taken out of the ultrahigh vacuum chamber for the after-treated T_c measurements.