Probing surface states of Cu/Ni thin films using x-ray absorption spectroscopy - art. no. 113401

Surface and interface properties of Cu thin films (1-4 monolayers) deposite d on Ni(100) have been extracted by means of x-ray absorption spectroscopy and analyzed in combination with ab initio density-functional calculations. An unoccupied Cu surface state is identified in an x-ray absorption spectr a and studied as a function of him thickness. Experimental data is supporte d by calculations of the layer-resolved density of states and the results f rom this combined theoretical-experimental effort show that the surface sta te is almost entirely located on the atomic layer closest to the vacuum. Ou r results also indicate strong hybridization between unoccupied states at t he Cu/Ni interface boundary.