The nature and the dispersion of the electronic collective excitations in different metal bilayers (Na, Ca, Ag) deposited onto the Cu(111) surface were investigated by angle-resolved electron energy loss spectroscopy. We found a nearly-flat behavior of the surface plasmon energy (absence of dispersion) in Ca and Ag bilayers, characterized by the presence of d electrons, in good agreement with theoretical predictions within the framework of the s-d polarization model. On the contrary, an initial negative dispersion was observed in the Na bilayer. The intensity of the surface plasmon was vanishing in the long-wavelength limit in all cases. (C) 2009 Elsevier B.V. All rights reserved.
Electronic properties of metallic bilayers deposited on Cu(111): A comparative study
FORMOSO, Vincenzo;Chiarello Gennaro
2009-01-01
Abstract
The nature and the dispersion of the electronic collective excitations in different metal bilayers (Na, Ca, Ag) deposited onto the Cu(111) surface were investigated by angle-resolved electron energy loss spectroscopy. We found a nearly-flat behavior of the surface plasmon energy (absence of dispersion) in Ca and Ag bilayers, characterized by the presence of d electrons, in good agreement with theoretical predictions within the framework of the s-d polarization model. On the contrary, an initial negative dispersion was observed in the Na bilayer. The intensity of the surface plasmon was vanishing in the long-wavelength limit in all cases. (C) 2009 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
