Coverage dependence of the work function of metals upon alkali-metal adsorption

Abstract

Alkali-metal adsorption on metal substrates leads to changes in the work function $\ensuremath{\Delta}\ensuremath{\varphi}$ with changing adsorbate coverage $\ensuremath{\theta}$. The function $\ensuremath{\Delta}\ensuremath{\varphi}$ goes through a minimum at a certain coverage. It is demonstrated by an Anderson-model calculation that the experimental data for $\ensuremath{\Delta}\ensuremath{\varphi}$ vs $\ensuremath{\theta}$ can be successfully explained if metallization is accompanied by a metal-substrate distance relaxation.