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

摘要

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 x 7) and Si(111)-(root 3 x root 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. (C) 2015 Elsevier B.V. All rights reserved.