Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-13T04:14:24.916Z Has data issue: false hasContentIssue false

Enthalpy of Formation of Yttria-Doped Ceria

Published online by Cambridge University Press:  03 March 2011

Weiqun Chen
Affiliation:
NEAT ORU and Thermochemistry Facility, University of California at Davis, Davis, California 95646
Theresa A. Lee
Affiliation:
NEAT ORU and Thermochemistry Facility, University of California at Davis, Davis, California 95646
Alexandra Navrotsky
Affiliation:
NEAT ORU and Thermochemistry Facility, University of California at Davis, Davis, California 95646
Get access

Abstract

Solid solutions (1 − x)CeO2 − xYO1.5 (0 ≤ x ≤ 0.36) were prepared by coprecipitation and sol-gel methods. Their enthalpy of formation relative to the end-members, fluorite-type cubic CeO2 and C-type YO1.5 was determined by oxide melt solution calorimetry. The enthalpy of drop solution shows a roughly linear trend with composition. Extrapolation to x = 1 gives the transition enthalpy of C-type to cubic fluorite YO1.5 as 22.2 ± 6.7 kJ/mol. This linear behavior is in contrast to the strong curvature seen in the ZrO2 − YO1.5 and HfO2 − YO1.5 systems. The slightly positive enthalpy of formation of CeO2 − YO1.5 is strikingly different from the strongly negative enthalpies of formation of ZrO2 − YO1.5 and HfO2 − YO1.5. The thermodynamics of CeO2 − YO1.5 is analyzed in terms of defect association and oxygen vacancy distribution. Specifically, the association of oxygen vacancies with the tetravalent cations in the zirconia and hafnia systems, in contrast to the preference of vacancies for nearest neighbor yttrium sites in the ceria systems, may explain the different energetics.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Steele, B.C.H., Lane, J.A., Zheng, K. and Bae, J. Ceramic materials for intermediate temperature solid oxide fuel cells. In Ceramics in Energy Applications (The Institute of Energy, London, U.K., 1994) p. 109.Google Scholar
2Tschope, A., Liu, W., Flytzani-Stephanopoulos, M. and Ying, J.Y.: Redox activity of nonstoichiometric cerium oxide-based nanocrystalline catalysts. J. Catal. 157, 42 (1995).CrossRefGoogle Scholar
3Yao, H.C. and Yao, Y.F. Yu: Ceria in automotive exhaust catalysts. J. Catal. 86, 254 (1984).CrossRefGoogle Scholar
4Mogensen, M., Sammes, N.M. and Tompsett, G.A.: Physical, chemical and electrochemical properties of pure and doped ceria. Solid State Ionics 129, 63 (2000).CrossRefGoogle Scholar
5Inaba, H. and Tagawa, H.: Ceria-based solid electrolytes. Solid State Ionics 83, 1 (1996).CrossRefGoogle Scholar
6Steele, B.C.H. In High Conductivity Solid Ionic Conductors , edited by Takahashi, T. (World Scientific, Singapore, 1989) pp. 402446.CrossRefGoogle Scholar
7Killer, J.A. and Steele, B.C.H.: Mass transport in anion-deficient fluorite oxides. In Nonstoichiometric Oxides, edited by Sorenson, O.T. (Academic Press, New York, NY, 1981) p. 254.Google Scholar
8Wang, D.Y., Park, D.S., Griffith, J. and Nowick, A.S.: Oxygen-ion conductivity and defect interactions in yttria-doped ceria. Solid State Ionics 2, 95 (1981).CrossRefGoogle Scholar
9Longo, V. and Podda, L.: Phase equilibrium diagram of the system ceria-yttria for temperatures between 900 and 1700 °C. J. Mater. Sci. 16, 839 (1981).CrossRefGoogle Scholar
10Lee, T.A., Molodetsky, I. and Navrotsky, A.: Enthalpy of formation of cubic yttria-stabilized zirconia. J. Mater. Res. 18, 908 (2003).CrossRefGoogle Scholar
11Lee, T.A. and Navrotsky, A.: Enthalpy of formation of cubic yttria-stabilized hafnia (c-YSH). J. Mater. Res. 19, 1855 (2004).CrossRefGoogle Scholar
12Navrotsky, A.: Recent progress and new directions in high temperature calorimetry. Phys. Chem. Miner. 2, 89 (1977).CrossRefGoogle Scholar
13Navrotsky, A.: Progress and new directions in high temperature calorimetry revisited. Phys. Chem. Miner. 24, 222 (1997).CrossRefGoogle Scholar
14Helean, K.B. and Navrotsky, A.: Oxide melt solution calorimetry of rare earth oxides: Techniques, problems, cross-checks, successes. J. Therm. Anal. Calorim. 69, 751 (2002).CrossRefGoogle Scholar
15Kim, D.J.: Lattice parameters, ionic conductivities, and solubility limits in fluorite-structure MO2 oxide (M = Hf4+, Zr4+, Th4+, U4+) solid solutions. J. Am. Ceram. Soc. 72, 1415 (1989).CrossRefGoogle Scholar
16Ushakov, S.V., Helean, K.B., Navrotsky, A. and Boatner, L.A.: Thermochemistry of rare-earth orthophosphates. J. Mater. Res. 16, 2623 (2001).CrossRefGoogle Scholar
17Putnam, R.L., Navrotsky, A., Cordfunke, E.H.P. and Huntelaar, M.E.: Thermodynamics of formation of two cerium aluminum oxides, CeAlO3(s) and CeAl12O19.918(s) and cerium sesquioxied, Ce2O3(s) at T =198.15 K. J. Chem. Thermodyn. 32, 911 (2000).CrossRefGoogle Scholar
18Dexpert-Ghys, J., Faucher, M. and Caro, P.: Site selective spectroscopy and structural analysis of yttria-doped zirconias. J. Solid State Chem. 54, 179 (1984).CrossRefGoogle Scholar
19Li, P., Chen, I.W. and Penner-Hahn, J.E.: Effect of dopants on zirconia stabilization—an X-ray absorption study: I, Trivalent dopants. J. Am. Ceram. Soc. 77, 118 (1994).CrossRefGoogle Scholar
20Li, P., Chen, I.W. and Penner-Hahn, J.E.: X-ray-absorption studies of zirconia polymorphs. II. Effect of Y2O3 dopant on ZrO2 structure. Phy. Rev. B 48, 10074 (1993).CrossRefGoogle ScholarPubMed
21Manning, P.S., Sirman, J.D., Desouza, R.A. and Kilner, J.A.: The kinetics of oxygen transport in 9.5 mol% single crystal yttria stabilized zirconia. Solid State Ionics 100, 1 (1997).CrossRefGoogle Scholar
22Khan, M.S., Islam, M.S. and Bates, D.R.: Cation doping and oxygen diffusion in zirconia: A combined atomistic simulation and molecular dynamics study. J. Mater. Chem. 8, 2299 (1998).CrossRefGoogle Scholar
23Islam, M.S. Computer simulation studies of Ceria-bared oxides. In Catalysis by Ceria and Related Material , edited by Trovarelli, A. (Imperial College Press, London, U.K., 2002) pp. 281309.CrossRefGoogle Scholar
24Minervini, L., Zacate, M.O. and Grimes, R.W.: Defect cluster formation in M2O3-doped CeO2. Solid State Ionics 116, 339 (1999).CrossRefGoogle Scholar
25Bogicevic, A., Wolverton, C., Crosbie, G.M. and Stechel, E.B.: Defect ordering in aliovalently doped cubic zirconia from first principles. Phys. Rev. B 64, 14106 (2001).CrossRefGoogle Scholar
26Cillet, R.M., Deportes, C.H., Robert, G. and Vitter, G.: Structural study in the hafnium oxide-yttrium oxide system. Rev. Int. Haut. Temp. Refract. 4, 269 (1967).Google Scholar
27Duclot, M., Vicat, I. and Deportes, C.H.: Ordered phase Y2Hf7O17 in the system hafnium dioxide-yttrium oxide. J. Solid State Chem. 2, 236 (1970).CrossRefGoogle Scholar
28Stacy, D.W. and Wilder, D.R.: The yttria-hafnia system. J. Am. Ceram. Soc. 58, 285 (1975).CrossRefGoogle Scholar
29Hannon, R.: Phase Equilibria in the Hafnia-Yttria System and Refinement of Some Zirconia Binary Systems (M.S. Dissertation, Pennsylvania State University, University Park, PA, 1985).Google Scholar
30Zacate, M.O., Minervini, L., Bradfield, D.J., Grimes, R.W. and Sickafus, K.E.: Defect clustere formation in M2O3-doped cubic ZrO2. Solid State Ionics 128, 243 (2000).CrossRefGoogle Scholar