Probing the metal-nonmetal transition in thin metal overlayers using resonant photoemission

Authors

Peter A. Dowben, Syracuse University and University of Nebraska-LincolnFollow
D. LaGraffe, Syracuse University
Dongqi Li, Syracuse University
G. Vidali, Syracuse University
L. Zhang, Syracuse University
L. Dottl, University of Wisconsin-Madison
M. Onellion, University of Wisconsin-Madison

Date of this Version

May 1991

Comments

Published by American Physical Society. Copyright 1991. Permission to use. Physical Rev. B 43 (1991) 10677–19689. http://prb.aps.org/.

Abstract

We have studied one and two monolayers of barium on Ni(111) and of mercury on Cu(100). Using resonant photoemission, we have found core excited electrons become delocalized with increasing barium coverage. Similarly, upon formation of the mercury bilayer (as determined by low-energy electron diffraction and by atom-beam scattering), there is a substantial increase in the screening of the photohole. A transition of the electronic structure akin to a metal-nonmetal (metal-insulator) transition is apparent in these final-state effects. The band structure for Hg is similar to the band structure expected for a free-standing film with a free-electron sd band. The delocalization of the core excited electrons resembles the exciton unbinding that occurs at the metal-nonmetal Mott transition.