Valence- and conduction-band states of NiO(100) thin films grown onto Ag(100) have been probed by photoemission (PE) and inverse photoemission (IPE) spectroscopy, respectively. In particular, emphasis is given to the empty states, for which contrasting data are reported on samples obtained by different procedures. The good quality of the investigated NiO sample surface has allowed us to deduce a reliable picture of the empty state spectral function. Exploiting k resolution it was possible to disentangle the various orbital contributions and clearly fix their energy position, including that of the so-called ligand hole excitation. A combined PE and IPE analysis points towards the nearly intrinsic nature of the investigated NiO.

• Received 13 April 2001

DOI:https://doi.org/10.1103/PhysRevB.64.165402