Adsorption of Se on Fe(100): An ab-initio study

V. CARDOSO SCHWINDT; P. BECHTHOLD; E.A. GONZÁLEZ; P.V. JASEN; A. JUAN; M. JENKO; B. SETINA BATIC

Viena

Conferencia; 15th Joint Vacuum Conference; 2014

The adsorption of atomic Se on the Fe(100) surface is examined using density functional theory (DFT). Selenium is adsorbed in the high-symmetry adsorption sites: bridge, 4-fold hollow and atop sites in coverages of 1/2, 1/4 and 1 monolayer (ML). The 4-fold hollow site is found to be the most stable (see Figure 1) and the bridge site result to be instable. The Se adsorption not results in a surface reconstruction as we found in the (110) surface previously reported [1]. Comparisons between Se-adsorbed and pure Fe surfaces revealed reductions in the magnetic moments of surface-layer Fe atoms in the vicinity of the Se as in the previous surface analysed. The density of states present a contribution of Se states at -5.0 eV and -13.2 eV stabilized after adsorption (see Figure 2). Se atom extends its interaction up second Fe layer atoms. In this study, the Se almost no presents magnetization. The Fe-Fe overlap population decrease and a Fe-Se bond are formed at expenses of the metallic bond.