Surface Plasmon Dispersions of Ag Adsorbed Si(111) Surfaces Studied by Angle-Resolved Electron Energy Loss Spectroscopy

Abstract
Surface plasmon dispersions (SPD) on clean Si(111)7×7 and three Ag adsorbed surfaces, RT deposited, √3-, and 3×1-structured surfaces were measured. The SPD on the clean surface was negative and similar to that of Si(001)2×1, but those of Ag deposited surfaces were positive. Hydrodynamic calculations of the SPD using the two step charge density model of the surface explained well the experimental SPDs on the Ag adsorbed surfaces and gave the charge distributions on the surfaces. For the clean surface the two step model was not adequate.