Band structure analysis of resonant photoemission in ZrO2

A detailed analysis of the density of states of the cubic phase of ZrO2 over a broad energy range, calculated by means of the linear muffin-tin orbital method, showed that the two experimental resonances at 39 and 45 eV could be explained in terms of electronic transitions within the local density approximation. The resonance at 39 eV is assigned to electronic transitions from the 4p to the 4d status of Zr. The calculated bulk 4p --> 4d transitions are about 36 eV. The discrepancy with experiment is due to out. underestimation of the band gap by about 3 eV. The higher energy resonance at 45 eV is assigned to electronic transitions From Zr 4p states to empty hybridized (Zr 4s and O 2p) conduction band states dominated by an O 2p contribution. Our calculation found this latter resonance at 3 eV below the experimental value. Here again the discrepancy is due to a much smaller calculated band gap.