Changes in the Electron Effective Mass across the Nonmetal-Metal Transition in Magnesium Overlayers

Using angle-resolved photoemission, dramatic changes in the electronic structure and the associated in-plane electron effective mass have been observed with increasing Mg coverages for Mg overlayers on Mo(112). There is clear evidence of a gradual evolution of the band structure and effective mass across the nonmetal-to-metal transition in the Mg overlayer. The results are in very good agreement with the relative change of the screening parameter determined by resonant photoemission.