Surface structure characterization of ultra-thin films of Au deposited on Pd(111)

Ultra-thin films of Au were deposited on the Pd(111) surface and then characterized by X-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED), and X-ray photoelectron diffraction (XPD). XPD analyses indicated that the gold films were 7 and 6 ML thick, for the annealing temperatures of 400 °C and 610 °C, respectively. The film interlayer distances exhibited an oscillatory behavior, with a 5% contraction between the top and the second layers, a 3% expansion between the second and the third layers, for the film annealed at 400 °C, and a 2% expansion in the interlayer distance between the top and the second layers and a 4% contraction between the second and the third layers, for the film annealed at 610 °C. The film annealed at 610 °C exhibited Au islands covering the Pd substrate surface, with some bare patches exposed. Experimental XPD patterns for Au 4f7/2 emitter (left) and Pd 3p1/2 emitter (right) for the Au film deposited on Pd(111) annealed at 610 °C.230