Angle-resolved and resonant photoemission study of the ZrO-like film on ZrC(1 0 0)

Angle-resolved photoemission spectroscopy (ARPES) and resonant photoemission spectroscopy (RPES) have been used to study the electronic structure of the ZrO-like film formed on a ZrC(1 0 0) 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 ¯ 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 ¯ → Γ ¯ 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.