SAMARIUM FILMS ON COPPER SINGLE-CRYSTALS

We have studied samarium films on Cu(100), Cu(110), and Cu(111) surfaces. These studies have concentrated on the geometric and electronic structure of the interface. The geometry of the interface was studied by LEED, and the electronic structure was investigated by XPS. Calibration of the coverage was done by measuring the Cu(2p) and Sm(3d) photolines and the Cu(M2,3VV) and Sm(N4,5O2,3N6,7) XAES spectra. We have seen some simple reconstructions in LEED e.g. c(8 x 2) on the (100) surface, c(6 x 2) on the (110) surface, and square-root 3 x square-root 3 R30-degrees on the (111) surface. At 400-degrees-C slightly distorted hexagonal LEED patterns were seen on both the (111) and (100) surface. These are ascribed to growth of a Sm-Cu compound on top of the copper substrate.