Insight into the structural and electronic properties of orthorhombic Cr3C2 (001) surface

By using the first-principle calculations, the surface relaxation, surface energies and work functions, surface electronic structure of orthorhombic Cr3C2 (001) surface have been calculated. The LDA computed values of surface energy and work function for the stoichiometric Cr3C2 (001) surface are 4.13 J/m2 and 4.4 eV, respectively. Results of the relaxed structure indicate that the major effect of atomic relaxations is in the top two layers, and the largest rumpling locates at the second layer. The Cr3C2 (001) surface has a stronger metallic character than the bulk duo to the appearance of the surface state. Mulliken population analysis also demonstrates the strong increase in the Cr-Cr metallic bonding on the top surface and considerable covalency for C-Cr bonding.