Abstract
Mechanical properties of acceptor (calcium and strontium)-substituted lanthanum chromites are reported as a function of composition, temperature and environment. The strength dependence on temperature for these perovskite conductors was found to depend on the acceptor type, with the calcium-substituted chromites showing a significant reduction in strength with increasing temperature, while the strength of strontium-substituted chromites was essentially invariant with temperature. The decrease in strength observed upon annealing in highly reducing environments was correlated to changes in lattice structure, stoichiometry and fracture morphology. A significant observation was the decrease in the cohesive strength of the grains relative to grain boundaries, beyond a critical oxygen vacancy concentration in the chromites. The structural changes in the chromite lattice upon reduction also resulted in decreased fracture toughness. © 1998 Chapman & Hall
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
N. Q. Minh and T. Takahashi, in “Science and Technology of Ceramic Fuel Cells” (Elsevier, Amsterdam, 1995).
N. Q. Minh, J. Amer. Ceram. Soc. 76 (1993) 563.
N. M. Sammes, R. Ratnaraj, and M. G. Fee, J. Mater. Sci. 29 (1994) 4319.
M. Mori, H. Itoh, N. Mori and T. Abe, in “Proceedings of the 3rd International Symposium on Solid Oxide Fuel Cells”, edited by S. C. Singhal and H. Iwahara (The Electrochemical Society, Pennington, NJ, 1993) p. 325.
N. M. Sammes, R. Ratnaraj and C. E. Hatchwell, in “Proceedings of the 4th International Symposium on Solid Oxide Fuel Cells (SOFC-IV)”, edited by M. Dokiya, O. Yamamoto, H. Tagawa and S. C. Singhal (The Electrochemical Society, Pennington, NJ, 1995) p. 952.
C. Milliken, S. Elangovan and A. Khandkar, in “Proceedings of the 3rd International Symposium on Solid Oxide Fuel Cells”, edited by S. C. Singhal and H. Iwahara (The Electrochemical Society, Pennington, NJ, 1993) p. 335.
C. S. Montross, H. Yokokawa, M. Dokiya and M. Anzai, in “Extended Abstracts of the 60th Meeting of the Electrochemical Society of Japan”, (1993) p. 263.
N. M. Sammes and R. Ratnaraj, J. Mater. Sci. 30 (1995) 4523.
C. S. Montross, H. Yokokawa, M. Dokiya and L. Bekessy, J. Amer. Ceram. Soc. 78 (1995) 1869.
C. S. Montross, H. Yokokawa and M. Dokiya, Scripta Mater. 34 (1996) 913.
S. W. Paulik and T. R. Armstrong, in “Program and Abstracts of the 1996 Fuel Cell Seminar”, Orlando, FL, November 1996, p. 131.
S. W. Paulik and T. R. Armstrong, in “Proceedings of the 2nd European Symposium on Solid Oxide Fuel Cells”, edited by B. Thorstensen (European Solid Oxide Fuel Cell Forum, Oberrohrdorf, Switzerland, 1996) p. 547.
G. R. Anstis, P. Chantikul, B. R. Lawn and D. B. Marshall, J. Amer. Ceram. Soc. 64 (1981) 533.
E. Schreiber, O. L. Anderson and N. Soga, in “Elastic Constants and Their Measurement” (McGraw-Hill, New York, 1973).
T. R. Armstrong, J. W. Stevenson, D. E. Mccready, S. W. Paulik and P. E. Raney, Solid State Ionics 92 (1996) 213.
E. R. Underwood, in “Quantitative Stereology” (Addison-Wesley, Reading, MA, 1970).
L. A. Chick, J. L. Bates and G. D. Maupin, in “Proceedings of the 2nd International Symposium on Solid Oxide Fuel Cells”, edited by F. Grosz, P. Zegers, S. C. Singhal and O. Yamamoto (Commission of the European Communities, Luxembourg, 1991) p. 621.
J. L. Bates, L. A. Chick and W. J. Weber, Solid State Ionics 52 (1992) 235.
L. A. Chick, J. Liu, J. W. Stevenson, T. R. Armstrong, D. E. Mccready, G. D. Maupin, G. W. Coffey, and C. A. Coyle, J. Amer. Ceram. Soc. (1996).
N. Sakai, T. Kawada, H. Yokokawa, M. Dokiya and I. Kojima, ibid. 76 (1993) 609.
C. P. Khattak and D. E. Cox, Mater. Res. Bull. 12 (1977) 463.
M. Mori, T. Yamamoto, H. Itoh and T. Abe, in “Proceedings of the 4th International Symposium on Solid Oxide Fuel Cells (SOFC-IV)”, edited by M. Dokiya, O. Yamamoto, H. Tagawa and S. C. Singhal (The Electrochemical Society, Pennington, NJ, 1995) p. 905.
E. L. Courtright, H. C. Graham, A. P. Katz and R. J. Kerans, WL-TR–91–4061, Wright Patterson Air Force Base, OH (1992).
S. M. Wiederhorn, in “Mechanical and Thermal Properties of Ceramics”, edited by J. B. Wachtman, Jr., National Bureau of Standards (US) Special Publication 303 (National Bureau of Standards, Washington, DC, 1969) p. 217.
G. Fantozzi, G. Orange, M. Gautier, J. P. Duraud, P. Maire, C. Legrauss and E. Gillet, J. Amer. Ceram. Soc. 72 (1989) 1562.
T. R. Armstrong, J. W. Stevenson, L. R. Pederson, and P. E. Raney, J. Electrochem. Soc. 143 (1996) 2919.
W. B. Hillig, J. Amer. Ceram. Soc. 76 (1993) 129.
R. D. Shannon, Acta Crystallogr. A32 (1976) 751.
R. Rice, J. Mater. Sci. 31 (1996) 4503.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Paulik, S.W., Baskaran, S. & Armstrong, T.R. Mechanical properties of calcium- and strontium-substituted lanthanum chromite. Journal of Materials Science 33, 2397–2404 (1998). https://doi.org/10.1023/A:1004359925766
Issue Date:
DOI: https://doi.org/10.1023/A:1004359925766