@article{353,
  keywords = {paper},
  author = {L. Dash and N Vast and P Baranek and MC Cheynet and Lucia Reining},
  title = {Electronic structure and electron energy-loss spectroscopy of ZrO2 zirconia},
  abstract = {The atomic and electronic structures of zirconia are calculated within density functional theory, and their evolution is analyzed as the crystal-field symmetry changes from tetrahedral [cubic (c-ZrO2) and tetragonal (t-ZrO2) phases] to octahedral (hypothetical rutile ZrO2), to a mixing of these symmetries (monoclinic phase, m-ZrO2). We find that the theoretical bulk modulus in c-ZrO2 is 30\% larger than the experimental value, showing that the introduction of yttria in zirconia has a significant effect. Electronic structure fingerprints which characterize each phase from their electronic spectra are identified. We have carried out electron energy-loss spectroscopy experiments at low momentum transfer and compared these results to the theoretical spectra calculated within the random phase approximation. We show a dependence of the valence and 4p (N-2,N-3 edge) plasmons on the crystal structure, the dependence of the latter being brought into the spectra by local-field effects. Last, we attribute low energy excitations observed in EELS of m-ZrO2 to defect states 2 eV above the top of the intrinsic valence band, and the EELS fundamental band gap value is reconciled with the 5.2 or 5.8 eV gaps determined by vacuum ultraviolet spectroscopy.},
  year = {2004},
  journal = {Phys. Rev. B},
  volume = {70},
  number = {24},
  month = {DEC},
  publisher = {AMERICAN PHYSICAL SOC},
  address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA},
  url = {http://dx.doi.org/10.1103/PhysRevB.70.245116},
  doi = {10.1103/PhysRevB.70.245116},
}