Hostname: page-component-77c89778f8-9q27g Total loading time: 0 Render date: 2024-07-19T01:49:03.794Z Has data issue: false hasContentIssue false
  • English
  • Français

Calculation of Defect Formation Energy from the Thermal Expansion Data for Lead Fluoride

Published online by Cambridge University Press:  16 February 2011

Brenda J. Schuler ,
T. S. Aurora ,
D. O. Pederson  and
S. M. Day
Brenda J. Schuler
Affiliation:
Philadelphia College of Pharmacy and Science, Philadelphia, PA 19104
T. S. Aurora
Affiliation:
Philadelphia College of Pharmacy and Science, Philadelphia, PA 19104
D. O. Pederson
Affiliation:
University of Arkansas, Fayetteville, AR 72701
S. M. Day
Affiliation:
Miami University, Oxford, OH 45056
Get access

Abstract

Lead fluoride is a superionic conductor with the fluorite structure. Results of the measurement of linear thermal expansion of lead fluoride (reported earlier in literature) showed a large increase in the thermal expansion coefficient near 700 K where the ionic conductivity has been shown to exhibit a sharp increase. It is believed that thermally-generated defects in a crystal lattice affect the thermal expansion coefficient. This idea was applied in the present analysis to calculate the defect formation energy (Ef) by using the literature values of the coefficient of thermal expansion. It was assumed that the thermal expansion in excess of that produced due to the lattice anharmonicity (δ∝) is proportional to the concentration of defects (n). With this assumption, one may write: δ∝ = c nº exp(-Ef/kT), where c is a constant. For lead fluoride, a plot of ln(δ∝) versus (l/T) yielded Ef = 0.56 eV which is lower than the literature values. The assumptions in this analysis and the discrepancy in the result are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 369: Symposium U – Solid State Ionics IV , 1994 , 325
Copyright
Copyright © Materials Research Society 1995

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

1. Crystals with the Fluorite Structure, edited by Hayes, W. (Clarendon, Oxford, 1974), p 111.Google Scholar
2. Harris, R. J., Johnston, G. T., Kepple, G. A., Krok, P. C. and Mukai, H., Appl. Opt. 16, 436 (1977).Google Scholar
3. Boyce, J. B. and Huberman, B. A., Phys. Rep. 51, 189 (1979).Google Scholar
4. Roberts, R. B. and White, G. K., J. Phys. C 19, 7167 (1986).Google Scholar
5. White, G. K., J. Phys. C 13, 4905 (1980).Google Scholar
6. Aurora, T. S., Pederson, D. O. and Day, S. M., Phys. Rev B15 41, 9647 (1990).Google Scholar
7. Manasreh, M. O., Pederson, D. O. and Aurora, T. S., Mat. Res. Soc. Symp. Proc. 135, 309 (1989).Google Scholar
8. Cartz, L., Proc. Phys. Soc. (London) B 68, 957 (1955).Google Scholar
9. Pathak, P. D. and Vasavada, N. G., J. Phys. C 3, L44 (1970).Google Scholar
10. Pathak, P. D. and Vasavada, N. G., J. Phys. C 3, L77 (1970).Google Scholar
11. Oberschmidt, J., Phys. Rev. B 23, 5038 (1981).Google Scholar
12. Aurora, T. S., Ph.D. dissertation, University of Arkansas, 1983.Google Scholar
13. Oberschmidt, J. M. and Lazarus, D., Phys. Rev. B 21, 2952 (1980).Google Scholar
14. Palchoudhuri, S. and Bichlie, G. K., Solid State Comm 69, 271 (1989).Google Scholar
15. Kennedy, J. H., Miles, R., and Hunter, J., J. Electrochem. Soc. 120, 1441 (1973).Google Scholar
16. Azimi, A., Carr, V. M., Chadwick, A. V., Kirkwood, F. G., and Saghafian, R., J. Phys. Chem. Solids 45, 23 (1984).Google Scholar
17. Samara, G. A., J. Phys. Chem. Solids 40, 509 (1979).Google Scholar
18. Boone, R. W. and Schoonman, J., J. Electrochem. Soc. 124, 28 (1977).Google Scholar
19. Benz, R., Z. Phys. Chem. (Frankfurt) 95, 25 (1975).Google Scholar
20. Schoonman, J., Dirksen, G. J., and Blasse, G., J. Solid State Chem. 7, 245 (1973).Google Scholar
21. Samara, G. A., Phys. Rev. B 13, 4529 (1976).Google Scholar
22. Boyce, J. B., Mikkelson, J. C. Jr., and O'Keefe, M., Solid State Comm. 21, 955 (1977).Google Scholar
23. Hwang, T. Y., Englesberg, M., and Lowe, I. J., Chem. Phys. Lett. 30, 303 (1975).Google Scholar
24. Gordon, R. E. and Strange, J. H., J. Phys. C 11, 3212 (1978).Google Scholar