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Oct 28

Aliovalent Doping of CeO2: DFT study of oxidation state and vacancy effects

Authors: Danny E. P. Vanpoucke, Patrick Bultinck, Stefaan Cottenier, Veronique Van Speybroeck, and Isabel Van Driessche,
Journal: J. Mater. Chem. A 2(33), 13723-13737 (2014)
doi: 10.1039/C4TA02449D
IF(2014): 7.443
export: bibtex
pdf: <JMaterChemA> <arXiv>

Abstract

The modification of CeO2 properties by means of aliovalent doping is investigated within the ab initio density functional theory framework. Lattice parameters, dopant atomic radii, bulk moduli and thermal expansion coefficients of fluorite type Ce1-xMxO2-y (with M = Mg, V, Co, Cu, Zn, Nb, Ba, La, Sm, Gd, Yb, and Bi) are presented for 0.00 ≤ x ≤ 0.25. The relative stability of the doped systems is discussed, and the influence of oxygen vacancies is investigated. It is shown that oxygen vacancies tend to increase the lattice parameter, and strongly decrease the bulk modulus. Defect formation energies are correlated with calculated crystal radii and covalent radii of the dopants, and are shown to present no simple trend. The previously observed inverse relationship between the thermal expansion coefficient and the bulk modulus in group IV doped CeO2 [J. Am. Ceram. Soc. 97(1), 258 (2014)] is shown to persist independent of the inclusion of charge compensating vacancies.

2 pings

  1. 39th ICACC: Day 1 » The Delocalized Physicist

    […] mainly located at the surface of the CeO2 particles, something I also expected from my own work on aliovalent doped CeO2, based on the defect formation energies of Cu and Co doping. Further presentations discussed […]

  2. 39th ICACC: day 3-5 » The Delocalized Physicist

    […] d) plays an important role with regard to stability and mechanical properties. In our second step dopants with an oxidation state different from +IV are considered, without the presence of oxygen vacancies. In this case, the same trends and […]

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