Temperature dependence of growth mode and epitaxial orientation on Au/Ni(111)

Growth processes of Au on Ni (111) surface at various substrate temperatures between 150 °C and 400 °C were investigated with low energy electron microscopy (LEEM). Au-Ni surface alloy forms in the beginning of growth and the following de-alloying results in the formation of the Au overlayer above 0.3 ML. The growth modes after that depend on the substrate temperature. Above about 300 °C, Au grows with layer-by-layer fashion up to 2 ML and the multilayer growth follows. On the contrary, the multilayer growth takes place from the initial stage below about 300 °C. Areas with the different epitaxial orientations of Au(111) film, Au111112¯//Ni111112¯ and Au1111¯1¯2//Ni111112¯, were separately imaged using dark-field LEEM. But the clear correlation between the area distribution with different epitaxial orientation and surface morphology was not recognized on the terrace.