Surface investigation by using a Scanning Kelvin Probe

In this paper we present the relative work function measurements of Platinum (Pt), Molybdenum (Mo), Lead (Pb), and Graphite (C) by using Kelvin Probe. The obtained results have shown that the work function measurements made in air are affected by the adsorption of oxygen. To measure the "true" metal work function the oxide layer has to be removed. Moreover in the experiments we measured the work function changes of a platinum sample after mechanically cleaning of the surface and exposure to air. The decrease in the work function leads to the conclusion that a positive outwards dipole layer on the surface is created.