We report self-consistent {\it ab initio} calculations of structural and electronic properties for the B- and Mg-terminated MgB2 (0001) surfaces. We employ ultra-soft pseudopotentials and plane wave basis sets within the generalized gradient approximation. The surface relaxations are found to be small for both B- and Mg-terminated surfaces. For the B-terminated surface, both B σ and π surface bands appear, while only one B π surface band exists near the Fermi level for the Mg-terminated surface. The superconductivity of the MgB2 surfaces is discussed. The work function is predicted to be 5.95 and 4.25 eV for the B- and Mg-terminated surfaces respectively. The simulated scanning tunneling microscopy images of the surfaces are not sensitive to the sign and value of the bias voltages, but depend strongly on the tip-sample distance. An image reversal is predicted for the Mg-terminated surface.
@article{arxiv.cond-mat/0106590,
title = {A first-principles study of MgB2 (0001) surfaces},
author = {Zhenyu Li and Jinlong Yang and J. G. Hou and Qingshi Zhu},
journal= {arXiv preprint arXiv:cond-mat/0106590},
year = {2009}
}