E(K) OF Ni ABOVE THE VACUUM LEVEL AS MEASURED BY VLEED ON RELAXED (110) SURFACE

Abstract

Varying incidence angle, VLEED spectra R(E) and dR/dE were measured on Ni(110) using target current technique. The results were interpreted with the reference spectra calculated on the basis of ground-state band structure. Some critical points (CPs) of E( k ) displayed themselves as dR/dE extremums while others remained invisible. Changing of incidence K || by a surface reciprocal vector switched manifesting CPs. Experimental CPs were determined by comparing energies of experimental dR/dE extremums with. their reference counterparts. Having mapped CPs along a variety of non-symmetry directions, bands along ΓX were constructed. Experimental E( k ) is consistent with other experimental data and APW calculations. Some peculiarities are attributed to the influence of surface relaxation. Capabilities of VLEED to provide PES with upper bands are discussed.