An STM study of desorption-induced thallium structures on the Si(111) surface

► We use STM to study desorption of thallium from the Si(111) surface. ► The process is reproduced by the first-order desorption model. ► Si adatoms are intrinsic to the (√3 × √3)-Tl resulting in the mosaic structure. ► Bonding of Tl atoms in the (1 × 1) and in the (√3 × √3) mosaic is of the same nature.