Surface Geometric and Electronic Structure of BaFe2As2(001)
cond-mat.mtrl-sci
/ Authors
V. B. Nascimento, Ang Li, Dilushan R. Jayasundara, Yi Xuan, Jared O'Neal, Shuheng Pan, T. Y. Chien, Biao Hu, X. B. He, Guorong Li
and 8 more authors
A. S. Sefat, M. A. McGuire, B. C. Sales, D. Mandrus, M. H. Pan, Jiandi Zhang, R. Jin, E. W. Plummer
/ Abstract
BaFe2As2 exhibits properties characteristic of the parent compounds of the newly discovered iron (Fe)-based high-TC superconductors. By combining the real space imaging of scanning tunneling microscopy/spectroscopy (STM/S) with momentum space quantitative Low Energy Electron Diffraction (LEED) we have identified the surface plane of cleaved BaFe2As2 crystals as the As terminated Fe-As layer - the plane where superconductivity occurs. LEED and STM/S data on the BaFe2As2(001) surface indicate an ordered arsenic (As) - terminated metallic surface without reconstruction or lattice distortion. It is surprising that the STM images the different Fe-As orbitals associated with the orthorhombic structure, not the As atoms in the surface plane.