Adsorption of La on W using probe-hole field emission microscopy

Abstract

The authors present results mainly on the variation of the work function phi ad, with the coverage theta of La on W, on the (011), (111) and (112) planes and the (161) region using probe-hole field emission microscopy. On the (011) plane, initially, phi ad decreases monotonically with an increase in the coverage theta , and attains the minimum at about theta =1. On the other planes, phi ad increases initially, and then decreases. Attempts have been made to estimate the adsorbate-substrate dipole moment and the charge transfer between them on the (011) plane. The results are discussed in the light of the geometrical structure of the adsurface.