Titration of submonolayer Au growth on Si(111)

We study and analyze the growth of submonolayers of Au on Si(111) by a complementary set of surface techniques. Specifically, we focus on the 5×2 and the α3×3 structures. We determine the gold coverage of these structures as a function of temperature by means of low energy electron diffraction (LEED) and low energy electron microscopy (LEEM). These results are independently calibrated by ex-situ ion scattering experiments. This allows us to present a phase diagram for this system. Remarkably, for all temperatures considered (820-1040 K), we find a coverage for the 5×2 phase that is significantly (≈10%) higher than the value of 0.6 monolayers which is assumed in the latest structural models. Therefore, a further refinement of the present picture of the quasi-one-dimensional 5×2 structure is required. © 2014 American Physical Society.