ELECTRON-EMISSION FROM THE INTERACTION OF HE PROJECTILES AND UV PHOTONS WITH LIF ON W(110)

The electronic structure of thin LF adlayers deposited on W(110) at ro om temperature is studied by ion impact electron spectroscopy (IIES) w ith He+ ions, metastable impact electron spectroscopy (MIES) with Heatoms, ultraviolet photoelectron spectroscopy (UPS), and to some exten t with electron energy loss spectroscopy (EELS). The transition from t he electronic structure of single adsorbed molecules to the emergence of the bulk structure could be studied by following the emergence of b ulk properties, in particular the bandgap, as a function of the LiF ex posure. The first step in the layer growth is molecular absorption of LiF. The next step is the formation of islands formed by the LiF molec ules. The production of vacancies in the 2p F orbital under the influe nce of the ionizing radiation is studied as a function of the LiF expo sure. Their relevance for the desorption processes induced by electron ic transitions (DIET) is discussed.