Temperature-dependent microstructure of evaporated Yb surfaces

In situ evaporated polycrystalline Yb films at different substrate temperatures ($10<T<~300$ K) were studied by surface-sensitive photoemission ($h\ensuremath{\nu}=40.8$ eV). The presence of substrcture in the surface-derived $4{f}^{13}$ components allowed an identification of multiple surface shifts as being due to different coordination numbers of surface atoms. The temperature-dependent intensity variation of the surface emission could be correlated with the temperature-dependent change of the surface microstructure.