Changes in electron localization and density of states near E_F across the nonmetal-metal transition in Mg overlayers

Authors

Jiandi Zhang, University of Nebraska-LincolnFollow
D.N. McIlroy, University of Nebraska-Lincoln
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

5-15-1994

Comments

Published by American Physical Society. Copyright 1994. Permission to use. Phys. Rev. B 49 (1994), 13780-13786. http://prb.aps.org/

Abstract

A nonmetal-to-metal transition in Mg monolayers on Mo(112) has been indicated by photoemission and resonant photoemission. The dramatic changes of the density of states, the dispersion of bands near E_F, and screening are observed across the nonmetal-to-metal transition. The changes of the resonance photon energy and the intensity of Mg 2p→εd excitation, with different coverages, indicate that there exists a correlation between the electronic structure (particularly final-state screening effects) and the overlayer structure. The commensurate-to-incommensurate transition beyond 0.5 monolayer of coverage corresponds to the overlayer nonmetal-to-metal transition, which is due to the hybridization of Mg s and p bands and represents a transition from a localized (bondlike) to a delocalized (bandlike) phase for divalent atoms.