Surface Geometric and Electronic Structure of BaFe2As2(001)

Authors :: Nascimento, V. B.
Li, Ang
Jayasundara, Dilushan R.
Xuan, Yi
O'Neal, Jared
Pan, Shuheng
Chien, T. Y.
Hu, Biao
He, X. B.
Li, Guorong
Sefat, A. S.
McGuire, M. A.
Sales, B. C.
Mandrus, D.
Pan, M. H.
Zhang, Jiandi
Jin, R.
Plummer, E. W.
Publication Year :: 2009
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.<br />Comment: 12 pages, 4 figures