Angle-resolved and resonant photoemission study of the ZrO-like film on ZrC(100)

Angle-resolved photoemission spectroscopy (ARPES) and resonant photoemission spectroscopy (RPES) have been used to study the electronic structure of the ZrO-Iike film formed on a ZrC(100) surface. It is found that, in addition to the O 2p band observed at 6-8 eV, states exist at 0.15 and 0.75 eV around the (M) over bar point. ARPES measurements show that the states at 0.15 and 0.75 eV disperse towards the lower binding energy side and cross the Fermi level along the (M) over bar -> (Gamma) over bar direction. RPES measurements show that the former state shows a resonant behavior characteristic of the intra-atomic Zr 4d resonance, suggesting that the state includes substantial contribution of Zr 4d orbitals. On the other hand, the latter state shows a resonant behavior similar to that of the O 2p state in ZrO. The resonance is thought to be caused through the inter-atomic deexcitation mechanism involving the emissions of O 2p electrons, and thus the latter state is ascribed to that mostly composed of the O 2p component. (C) 2007 Elsevier B.V. All rights reserved.