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The objective of this work was to study the electrodeposition of silicon in molten KF-LiF (eut)-K2SiF6 (5 mol%) on Ag and Si substrates at 550oC and 800oC. In addition electrochemical studies of the system were performed on silver, tungsten and glassy carbon substrates at 800oC. The electrochemical measurements confirmed that the reduction of Si is diffusion controlled and occurs in two steps. On silver, dense, coherent films with good adhesion and no inclusions of salt were obtained at 800oC at the growth rate 52 µm/hour. On silicon, the microstructure seemed to consist of small "randomly" oriented crystals. At 550oC, the deposit became porous and powderish both on silver and silicon substrates. The low temperature combined with the relatively high current densities applied was believed to hinder crystal growth.

CO adsorption on Ce-Pt͑111͒ has been studied by temperature programmed desorption ͑TPD͒, low energy electron diffraction ͑LEED͒ and x-ray photoelectron spectroscopy ͑XPS͒. Thin layers ͑1 to 3 ML͒ of Ce on Pt͑111͒ form upon annealing to 1000 K a surface alloy which most likely is Pt terminated. The CO overlayer structure on Ce-Pt͑111͒ at saturation coverage is argued to be an intermediate between ͑2 ϫ 2͒ and c͑4 ϫ 2͒ superstructures. This intermediate structure exhibits a c͑4 ϫ 2͒ LEED pattern in which some of the spots appear together as ordered triangles. The thermal desorption spectra for the Ce-Pt͑111͒ surface alloy are shifted down by a temperature of about 120 K compared to the CO desorption of pure Pt͑111͒, most likely due to a change in the d-band due to hybridization between Ce and Pt states, which results in a weakening of the resonant interaction between CO 5 and Pt 5d states.

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