VALENCE INSTABILITY AT THE SURFACE OF RARE-EARTH-METALS - SAMARIUM

Abstract

Employing both LMTO and FLAPW band methods, we performed self-consistent electronic structure calculations on various Sm systems: Sm-atom, bulk-Sm, monolayer-Sm, 5-layer fcc(001) Sm and Sm/Al(001). It is found that the electronic properties, such as charge density, density of states, and the valence at the surface are not drastically different from the values in the bulk. Furthermore, for the ideal fcc Sm(001) surface we found that the trivalent state is energetically more stable than the divalent by about 0.2 Ry.