The Low Energy Auger Electron Spectroscopy Lines as an Index of the Ba Overlayer Order on the Ni(110) Surface

We investigate the interaction of Ba with the Ni(110) surface at elevated temperatures by means of Auger electron spectroscopy and low energy electron diffraction. The results show that annealing of the substrate causes desorption and ordering of the initially amorphous overlayer, resulting in c and structures. It is observed that the induced ordering crucially affects the lineshape of the double Auger transition line Ba(73 eV)N45O23P1, establishing this line as an index of ordering of the Ba overlayer. The underlying physics of this effect is discussed.