The study of intrinsic defect state of FeSe with scanning tunneling microscopy

Kunliang Bu; Bo Wang; Wenhao Zhang; Ying Fei; Yuan Zheng; Fangzhou Ai; Zongxiu Wu; Qisi Wang; Hongliang Wo; Jun Zhao; Chuanhong Jin; Yi Yin

doi:10.1103/physrevb.100.155127

arXiv · 1908.03427

The study of intrinsic defect state of FeSe with scanning tunneling microscopy

Kunliang Bu·Bo Wang·Wenhao Zhang·Ying Fei·Yuan Zheng·Fangzhou Ai·Zongxiu Wu·Qisi Wang·Hongliang Wo·Jun Zhao·Chuanhong Jin·Yi Yin

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Abstract

We apply high resolution scanning tunneling microscopy to study intrinsic defect states of bulk FeSe. Four types of intrinsic defects including the type I dumbbell, type II dumbbell, top-layer Se vacancy and inner-layer Se-site defect are extensively analyzed by scanning tunneling spectroscopy. From characterized depression and enhancement of density of states measured in a large energy range, the type I dumbbell and type II dumbbell are determined to be the Fe vacancy and Se$_\mathrm{Fe}$ defect, respectively. The top-layer Se vacancy and possible inner-layer Se-site vacancy are also determined by spectroscopy analysis. The determination of defects are compared and largely confirmed in the annular dark-field scanning transmission electron microscopy measurement of the exfoliated FeSe. The detailed mapping of defect states in our experiment lays the foundation for a comparison with complex theoretical calculations in the future.

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Kunliang Bu, Bo Wang, Wenhao Zhang, Ying Fei, Yuan Zheng, Fangzhou Ai, Zongxiu Wu, Qisi Wang, Hongliang Wo, Jun Zhao, Chuanhong Jin, Yi Yin. 2019-08-09. The study of intrinsic defect state of FeSe with scanning tunneling microscopy. https://doi.org/10.1103/physrevb.100.155127

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