[Abstract list] [Previous] [Next] [Home]

J. Phys.: Condens. Matter 6 (1994) pp. L613-L618

Surface states as probes of buried impurities

S. Crampin

Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, United Kingdom

Abstract
Shockley surface states at metal surfaces decay exponentially into the crystal, typically penetrating several interplanar spacings. Within this distance defects such as impurity atoms will scatter the surface state electrons and give rise to characteristic standing wave patterns in the local density of states outside the surface, similar to those recently detected with the STM due to scattering by adatoms. A multiple scattering theory is developed to model this situation and applied to impurities near the Cu(111) surface. The results are discussed within a two-dimensional scattering model and the prospects for observation with the STM considered.