Abstract
The perovskite structured material LaGaO3 doped with 10 mol-% strontium and 20 mol-% magnesium was prepared by two different wet-chemical synthesis routes. The total conductivity was measured in air and under an oxygen partial pressure of 10−20 bar. There was a decrease by 10 % in 4 days when the atmosphere was changed from air to 10−20 bar. This process is reversible. Hebb-Wagner measurements resulted in values for the electronic minority charge carrier conductivities in pure oxygen of log σh [S/cm]=−4.02 and log σe [S/cm]=−15.5 for the holes and electrons, respectively, at 600 °C. In the partial pressure range 10−3 bar≤p(O2)≤1 bar, a slope of +1/4 was observed for d(log (σh)) / d(log (p(O2)) at T=600, 650 and 700 °C. That is in agreement with the assumption of a large number of oxygen vacancies. The diffusion coefficient of the holes was evaluated from the relaxation curves to be 1.1*10−7 cm2/s at 600 °C. Degradation effects were observed under highly reducing conditions which are attributed to the formation of gallium-platinum alloys and the loss of gallium oxide if O2 is available in the gas phase.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
7. References
H.L. Tuller and A.W. Nowick, J. Electrochem. Soc.122, 255 (1975).
T. Takahashi and H. Iwahara, Energy Conversion11, 105 (1971).
T. Ishihara, T. Matsuda and Y. Takita, J. Amer. Chem. Soc.116, 3801 (1994).
P. Huang and A. Petric, J. Electrochem. Soc.143, 1644 (1996).
M. Feng and J.B. Goodenough, J. Solid State Inorg. Chem.31, 663 (1994).
T. Ishihara, M. Honda, T. Shibayama, H. Minami, H. Nishiguchi and Y. Takita, J. Electrochem. Soc145, 3177 (1998).
K. Yamaji, T. Horita, M. Ishikawa, N. Sakai, H. Yokokawa and M. Dokiya, Proc. 5th Int. Symp. Solid Oxide Fuel Cells, Electrochem. Soc. Proc.97–40, 1041 (1997).
M. H. Hebb, J. Chem. Phys.20, 185 (1952).
C. Wagner, in: Proc. 7th Meet. Int. Comm. Electrochem. Thermodyn. Kin., Lindau 1955 Butterworth Sci. Publ., p. 361–377.
K. Huang, M. Feng and J.B. Goodenough, Electrochem. Soc. Proc.96–27, 7 (1996).
K. Huang, M. Feng and J.B. Goodenough, J. Amer. Ceram. Soc.79, 1100 (1996).
F. Berckemeyer, Dissertation, Kiel University 1999.
H. Rickert, Einführung in die Elektrochemie fester Stoffe, Springer Verlag (1973) p. 106 ff.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Schmidt, S., Berckemeyer, F. & Weppner, W. Investigations of electronic minority charge carrier conductivity in La0.9Sr0.1Ga0.8Mg0.2O2.85 . Ionics 6, 139–144 (2000). https://doi.org/10.1007/BF02375558
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02375558