Multilayer structures composed of 3d transition metals were investigated by AES in combination with sputter depth profiling. The samples were trilayers Permalloy/Cu/Permalloy, Co/Cu multilayers and a spin-valve structure. Overlapping Auger peaks were separated by a fit-to-spectra of bulk standards. Sample rotation during sputtering improves the depth resolution and made detection of unintentionally deposited Cu possible. For very thin films the depth profiles are influenced by measuring effects. The effects of atomic mixing, surface roughness and information depth onto the depth profiles in the spin-valve structure were simulated using the MRI model.