On the origin of the Ru-3d5/2 satellite feature from RuO2(110)

High resolution core level spectroscopy in combination with density functional theory calculations are used to study the satellite feature of the Ru-3d(5/2), core level spectrum whose interpretation is still a matter of debate. We present evidence that the satellite peak is not related to any structural properties of the RuO2(1 1 0) surface. The binding energy shift between the Ru-3d(5/2) component and the satellite peak is close to the electron energy loss due to plasmon excitation. We propose therefore that the satellite peak is due to excitation of the RuO2 plasmon. (C) 2002 Elsevier Science B.V. All rights reserved.