Table 1. Calculated Lattice Constant a0, Band Gap Eg, High-Frequency Dielectric Constant ε∞, Born Effective Charges ZCe* and ZO, and Surface Energies of CeO2 Using VASP Compared with Previous Experimental and Theoretical Results.
| a0 (Å) | Eg (eV) | ε∞ | ZCe* | ZO* | E(100)surf(J m–2) | E(110)surf(J m–2) | E(111)surf(J m–2) | |
|---|---|---|---|---|---|---|---|---|
| PBE+U (UCe 4f = 5 eV)a | 5.490 | 2.29 | 6.59 | 5.53 | –2.77 | 1.45 | 1.06 | 0.69 |
| PBEsol+U (UCe 4f = 5 eV)a | 5.435 | 2.41 | 6.57 | 5.51 | –2.75 | 1.77 | 1.27 | 0.90 |
| PBE0a | 5.397 | 4.38 | 5.67 | 5.67 | –2.84 | 1.61 | 1.21 | 0.85 |
| PBEsol0a | 5.361 | 4.46 | 5.68 | 5.68 | –2.84 | 1.83 | 1.33 | 0.96 |
| HSE06a | 5.396 | 3.63 | 5.71 | 5.67 | –2.84 | 1.59 | 1.20 | 0.84 |
| PBE+U (UCe 4f = 5 eV)b | 5.489 | 1.44 | 1.06 | 0.71 | ||||
| PBEsol+U (UCe 4f = 5 eV)c | 5.431 | 6.55 | 5.53 | –2.76 | ||||
| PBE0d | 5.403 | 4.35 | ||||||
| PBE0e | 5.401 | 1.64 | 1.27 | 0.86 | ||||
| PBEsol0d | 5.368 | 4.40 | ||||||
| HSE06f | 5.40 | 3.50 | ||||||
| GW0g | 3.88 | |||||||
| Experiment | 5.411h | 2.9–3.3k | 5.31q | 1.20 ± 0.2 (averaged)r | ||||
| 5.401i | 4.0l | |||||||
| 5.395j | 3.6–4.11m | |||||||
| 4.0n | ||||||||
| 4.4o | ||||||||
| 4.3–4.4p | ||||||||
Present work.
Reference (121).
Reference (122).
Reference (37).
Reference (38).
Reference (35).
Reference (123).
Low-temperature measurement at 100 K.113
Steady-state and ultrafast transient absorption spectra measurement on stoichiometric CeO2 thin film. A revised optical band gap of 4 eV was proposed for bulk ceria, and the absorption tail below 4 eV was identified as the Urbach tail.117
Optical measurement on polycrystalline CeO2 films with 140–180 nm thicknesses.124
The electron energy loss spectroscopy (EELS) spectrum captured the O2p → Ce4f transition starting at 4 eV on single-crystal thin films, and the intensity between 0 and 3 eV indicates the Ce3+ state.120
High-resolution EELS study on stoichiometric thin films observed a 4.4 eV energy loss from O2p to the empty Ce4f state transition.119
Measurement from the optical absorption spectrum on the CeO2 nanoparticles.118
Transmissivity and reflectivity measurement on CeO2 quasi-single crystal sample.83