Identification of surface terminations of iron pnictides with low-temperature STM/STS

ORAL

Abstract

The alkaline-earth metal iron pnictide superconductor AEFe2As2 (AE$=$Ca, Sr, Ba) have been studied extensively with modern surface techniques, such as scanning tunneling microscopy/spectroscopy (STM/STS) and Angle Resolved Photoemission Spectroscopy (ARPES). Yet the surface termination upon cleaving is still controversial. Hence, the interpretation of those results of STM/STS and reconcile with results of other surface techniques tend to be challenging. We have performed a systematic low-temperature STM/STS study on a series of (Ca,Na)Fe2As2, (Ba,K)Fe2As2, Ba(Fe,Co)2As2, and BaFe2(As,P)2. We found that, with cryogenic cleaving method, all three crystalline atomic layers can be revealed and identified. We will discuss their identities and their implications.

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Authors

  • Jihui Wang

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Ang Li

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Jihua Ma

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Zheng Wu

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Jiaxin Yin

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Bing Lv

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • C.W. Chu

    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • A. Sefat

    • Oak Ridge National Laboratory

  • M. McGuire

    • Oak Ridge National Laboratory

  • B. Sales

    • Oak Ridge National Laboratory

  • D. Mandrus

    • University of Tennessee

  • Chenglin Zhang

    • University of Tennessee

  • Pengcheng Dai

    • University of Tennessee

  • Rongying Jin

    • Department of Physics and Astronomy, Louisiana State University

  • Jiandi Zhang

    • Department of Physics and Astronomy, Louisiana State University

  • E.W. Plummer

    • Department of Physics and Astronomy, Louisiana State University

  • Genfu Chen

    • Institute of Physics, Chinese Academy of Sciences

  • Hong Ding

    • Institute of Physics, Chinese Academy of Sciences

  • Shuheng H. Pan

    • Department of Physics and Texas Center for Superconductivity, University of Houston, and Institute of Physics, Chinese Academy of Sciences