Cesium growth on the SrTiO3(100) surface

Abstract

We investigate Cs adsorption on the SrTiO3(100) surface at room temperature by means of Auger electron spectroscopy, low energy electron diffraction, electron energy loss spectroscopy, thermal desorption spectroscopy and work function measurements. Cesium grows in a single amorphous layer, showing different morphology from that on other insulating substrates. The Cs overlayer approximates a two-dimensional metallic phase. No indications for the reduction of the substrate and a Cs–O compound are found. Thermal annealing desorbs part of the metallic Cs, inducing at the same time the surface diffusion of the Cs adatoms to higher binding energy states. The growth and adsorption kinetics of Cs on the STO, shows substantial differences to that of other alkalis such as K and Li. The reasons for that are discussed.