On the influence of adsorbates on heteroepitaxy: work function oscillations during deposition of copper on platinum (111)
In the present paper we show results of dynamical work function measurements during the growth of multilayer films of Cu on Pt(111). The obtained data show in the temperature range between 350-450 K a slightly temperature dependent work function decrease due to Cu deposition. Intermittant coadsorption of oxygen on a previously deposited Cu film of 2 ML thickness results in an oscillatory work function change (∆Ф) during further Cu deposition. The amplitude of the ∆Ф oscillations depends significantly on substrate temperature and deposition rate. These experimental results are discussed in terms of a growth model which considers the influence of surface morphology on the work function via the so-called Smoluchowski effect.