New electronic states close to the Fermi edge in the c(2 x 2) MnCu(100) surface alloy

In the present study we investigate the electronic structure of the c(2 x 2 )Mn/Cu(100) surface alloy which is formed by adsorption of 0.5 ML of Mn on Cu(100) at room temperature. We show that the electronic structure of the M nCu surface alloy is very different to that of the clean Cu(100) surface. W e focus our investigation on the electronic structure related to electronic states close to the Fermi edge. The experimental synchrotron ultraviolet p hotoemission spectroscopy results are compared with theoretical calculation s based on the surface Green's function matching technique, using a semiemp irical tight-binding hamiltonian. The theoretical results are in very good agreement with the experimental ones and confirm the surface origin of the observed new spectral features. (C) 2001 Elsevier Science B.V. All rights r eserved.