A first-principles electronic structure study of the high-symmetry surfaces of fcc americium

Abstract

Full-potential all-electron density-functional calculations with mixed basis APW + lo/LAPW have been carried out to investigate the electronic and geometric properties of the (1 1 0) surface of fcc Am(II) and compared with the corresponding properties of the (1 1 1) and (0 0 1) surfaces. In particular, the quantum size effects in the surface energies and the work functions of the (1 1 0) ultra-thin films up to seven layers at the anti-ferromagnetic ground state with spin-orbit coupling (AFM-SO) have been studied and compared with those of the (1 1 1) and (0 0 1) surfaces. A strong quantum size effect of work function up to seven layers in the fcc Am (1 1 0) surfaces is observed. The work function of the (1 1 0) surface is predicted to be 2.86 eV to be compared with 2.93 and 3.06 eV for (0 0 1) and (1 1 1) films at the ground state, respectively. On the other hand, the surface energy becomes relatively stable once the number of layers reaches three for all three surfaces. Density of states show that the 5f electrons in all three fcc Am surfaces are primarily localized. In addition, the present work of fcc Am high symmetry surfaces has been compared in detail with the corresponding available δ-Pu surface studies.