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 be en observed with increasing Mg overlayers on Mo(112). There is clear e vidence of a gradual evolution of the band structure and effective mas s across the nonmetal-to-metal transition in the Mg overlayer. The res ults are in very good agreement with the relative change of the screen ing parameter determined by resonant photoemission.