Potassium on Ni(111): Quantitative determination and electronic structure

Thermal desorption spectroscopy (TDS), low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), electron energy-loss spectroscopy (EELS), and x-ray photoelectron spectroscopy (XPS) techniques have been used to investigate the K adsorption on Ni(111). A quantitative evaluation of the K deposit is established from the combined use of TDS, LEED, and AES. The K electronic structure has been studied using AES, EELS, and XPS. Up to the monolayer completion the observed energy shifts are interpreted in terms of a continuous lowering of the positive charge carried by the K additive (charge transfer of about 0.5 electron) as the K coverage is increased.