  We present a study of the rubidium adsorption on the Si(111)-(7x7) surface
and the related Rb-induced reconstructions as a function of deposition
temperature and Rb-coverage via scanning tunneling microscopy (STM) and
low-energy electron diffraction (LEED). Sample analysis via LEED allowed to
observe for the first time a Rb/Si(111)-(6x1) reconstruction. The STM image
analysis allowed to obtain the first real space characterization of the
Rb/Si(111)-(3x1) surface. In addition, STM provided a direct and local
information on the surface arrangement as well as further insights on the
interaction between Si and Rb atoms and on the growth dynamics.
