Electronic structure of alkali-metal monolayers on Cu(111)

We have studied the formation of monolayer films of lithium, sodium, potassium and cesium atoms on Cu(111) at room temperature with angle-resolved inverse and direct photoemission, and monitored the coverage-dependent changes of the empty and occupied electronic density of states of the alkali adsorbates. All alkali metals formed 2 × 2 overlayer structures with characteristic two-dimensional electronic band structures. © 1993.