ADSORPTION AND NUCLEATION OF HAFNIUM ON FACETS AND STEPPED SURFACE-AREAS OF TUNGSTEN

The adsorption of Hf deposited from vapor in ultra-high vacuum onto th ermally cleaned surfaces of W has been studied using field electron em ission microscopy. Three-dimensional nucleation and two-dimensional la yer formation on structurally and topographically different areas of t he substrate were observed for various annealing temperatures and vari ous amounts of The deposited adsorbate. The dependence of the average work function on the adsorbate coverage as well as on the structural a nd morphological changes of the adsorption layer, involved by annealin g at various temperatures, has been measured