Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-29T06:57:17.643Z Has data issue: false hasContentIssue false
  • English
  • Français

Coulometric Titration Studies of Nonstoichiometric Nanocrystalline Ceria

Published online by Cambridge University Press:  10 February 2011

O. Porat ,
H. L. Tuller ,
E. B. Lavik  and
Y.-M. Chiang
O. Porat
Affiliation:
Center for Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
H. L. Tuller
Affiliation:
Center for Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
E. B. Lavik
Affiliation:
Center for Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
Y.-M. Chiang
Affiliation:
Center for Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
Get access

Abstract

Oxygen nonstoichiometry measurements in nanocrystalline ceria, x in CeO2-x, were performed using coulometric titration. The measurements reveal large apparent deviations from stoichiometry, of the order of 10−3 − 10−4 at T = 405 − 455 °C and Po2 = 0.21 − 10−5 atm, as compared to levels of ∼10−9 for coarsened materials under the same conditions. The level of nonstoichiometry is, however, larger then expected from previous electrical conductivity data of nanocrystalline ceria. In addition, x ∝ Po2−½ while Σ ∝po2−1/6. The observed dependence of x(Po2, T) can be explained by either the formation of neutral oxygen vacancies at or near the interface, or by surface adsorption.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 457: Symposium V – Nanophase and Nanocomposite Materials II , 1996 , 99
Copyright
Copyright © Materials Research Society 1997

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

[1] Gleiter, H., Progress in Materials Science 33, 1 (1990).Google Scholar
[2] Birringer, R., Herr, U. and Gleiter, H., Trans. Jpn. Inst. Met. 27 suppl., 43 (1986).Google Scholar
[3] Tscoepe, A. and Ying, J.Y., in Nanophase Materials: Synthesis-Properties-Applications, edited by Hadjipanayis, G.C. and Siegel, R.W. (Kluwer Academic Publ., Netherlands, 1994), p. 781.Google Scholar
[4] Chiang, Y.-M., Lavik, E.B., Kosacki, I., Tuller, H.L. and Ying, J.Y., Appl. Phys. Lett. 69, 185 (1996).Google Scholar
[5] Chiang, Y.-M., Lavik, E.B., Kosacki, I., Tuller, H.L. and Ying, J.Y., J. Electroceramics, in press.Google Scholar
[6] Tuller, H.L. and Nowick, A.S., J. Electrochem. Soc. 126, 209 (1979).Google Scholar
[7] Porat, O. and Tuller, H.L., J. Am. Ceram. Soc., in press.Google Scholar
[8] Porat, O. and Riess, I., J. Electrochem. Soc. 141, 1533 (1994).Google Scholar