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, †,}

(a) The variation of Te-3d spectra with the increase of the etching thickness and after vacuum annealing. (b) Se-3d and Fe-3p spectra with the increase of the etching thickness and after vacuum annealing compared with those of the as-grown film, a peak at 52.9 eV appears after etching and decreases after annealing.