Thickness-dependent spin-resolved photoemission from ultrathin Ag films on Si(111)

Electronic structure of ultrathin Ag films on Si(111) is investigated with spin- and angle-resolved photoemission spectroscopy using unpolarized light. Photoelectrons leaving d states of Ag reveal spin polarization with the polarization vector parallel to the sample surface. The effect is observed for the Ag films which have bulk-like crystallographic structure with coverages down to 1 monolayer, for Ag wetting layer on Si(111)-(7 × 7) and Si(111)-(3×3)Ag surface. It is found that the polarization magnitude increases with Ag thickness. The observed changes have been attributed to the changes in the Ag film morphology.