Core-level study of the phase transition on the Ge(111)-c(2×8) surface

Abstract
Measurements of the Ge 3d core level of the Ge(111) surface have been performed between room temperature, where the surface shows a c(2×8) reconstruction, and 400 °C, where the reconstruction has disappeared. Analysis of the data shows that no significant changes occur in either the binding energies or the relative intensities of the two different surface contributions. This shows that the phase transition is of the order-disorder type. A simple model for the occurrence of disorder is proposed.