Structure and properties of samarium overlayer and Sm/Rh surface alloy on Rh(100)

The structure and properties of Sm overlayer and Sm/Rh surface alloy have b een investigated with Auger electron spectroscopy (AES), low energy electro n diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and temperatu re programmed desorption spectroscopy (TDS). The growth of Sm on Rh(100) at room temperature (RT) appears following the Stranski-Krastanov growth mode and only the trivalent state Sm is observed from XPS results. Thermal trea tment of the Sm film at 900 K leads to the formation of ordered surface all oy which shows the c(5 root2 x root2)R45 degrees and c(2 x 2) LEED patterns . Annealing the Sm film at temperature above 400 K makes the binding energy (B.E.) of Sm 3d(5/2) shift to higher energy by 0.7 eV, which indicates cha rge transfer from Sm to Rh(100) substrate, causing the increase of CO desor ption temperature.