Determination of the electronic density of states near buried interfaces: Application to Co/Cu multilayers

High-resolution ${\mathit{L}}_3$ x-ray absorption and emission spectra of Co and Cu in Co/Cu multilayers are shown to provide unique information on the occupied and unoccupied density of d states near buried interfaces. The d bands of both Co and Cu interfacial layers are shown to be considerably narrowed relative to the bulk metals, and for Cu interface layers the d density of states is found to be enhanced near the Fermi level. The experimental results are confirmed by self-consistent electronic structure calculations. © 1996 The American Physical Society.