Abstract
Electrical conductivity of thermally grown Cr2O3 has been measured as a function of temperature and over a range of oxygen partial pressures from that of air to that of the Cr/Cr2O3 equilibrium. The conductivity showed p-type behavior over the range of the present investigation. At temperatures above 1000°C, the conductivity values were independent of oxygen partial pressure and indicated intrinsic semiconductor behavior. The mobility of holes, determined by measuring conductivity at fixed compositions (i.e., fixed δ in Cr2-δO3), increased with temperature. This behavior can be attributed to hopping-type conduction. For δ ∼ 10−5, the activation energy for hole hopping was 0.248 eV, and the calculated hole mobilities were 5.4x10−2 and 2.4x10−1 V/cm2 · s at 500 and 1000°C, respectively. The oxidation kinetics of Cr were determined by measuring the electrical conductivity and electromotive force across the oxide layer at 875°C. The result agreed well with the oxidation data obtained in thermogravimetric tests.
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References
P. Kofstad,High Temperature Corrosion (Elsevier Applied Science, England, Essex, 1988);Nonstoichiometry, Diffusion and Electrical Conductivity in Binary Metal Oxides (Wiley Interscience, New York, 1972).
K. Hoshino and N. L. Peterson,J. Am. Ceram. Soc. 66, C202 (1983).
H. C. Graham and H. H. Davis,J. Electrochem. Soc. 54, 89 (1971).
C. Greskovich,J. Am. Ceram. Soc. 67, C112 (1984).
K. P. Lillerud and P. Kofstad,Oxid. Met. 17, 127, 177, 195 (1982).
A. Atkinson and R. I. Taylor,NATO ASI Ser. B129, 285 (1984).
J.-H. Park, W. E. King, and S. J. Rothman,J. Am. Ceram. Soc. 70, 880 (1988).
W. C. Hagel and A. U. Seybolt,J. Electrochem. Soc. 108, 1146 (1961).
T. F. Kassner, L. C. Walter, and R. E. Grace, inProceedings of the Symposium on Thermodynamics: Nuclear Materials and Atomic Transport in Solids (International Atomic Energy Agency, Vienna, 1966), vol. II, p. 357.
W. Hagel,J. Am. Ceram. Soc. 48, 70 (1965).
M. J. Graham, J. I. Eldridge, D. F. Mitchel, and R. J. Hussey, private communication.
W. E. King and J.-H. Park, inProceedings of the 1988 Spring Meeting of the Materials Research Society (Materials Research Society, Pittsburgh, 1989), vol. 122, p. 193.
M.-Y. Su, H.-Y. Chang, and G. Simkovich,NATO ASI Ser. B129, 385 (1984).
T. Matsui and K. Natio,J. Nucl. Mater. 120, 115 (1984).
H. Nagai, T. Fujikawa, and H.-I. Shoji,Trans. Jpn. Inst. Met. 24, 581 (1983).
Y. D. Tretyakov and R. A. Rapp,Trans. Metall. Soc. AIME 245, 1235 (1969).
J.-H. Park,Physica B150, 80 (1988).
K. Natesan, inProceedings of the Symposium on Oxidation of Metals and Associated Mass Transport, M. A. Dayanadaet al, eds. (The Metallurgical Society, Warrendale, Pennsylvania, 1987), p. 161.
Handbook of Chemistry and Physics, 61st ed. (CRC press, 1981).
L. Heyne, J. B. Wachtman, and A. D. Franklin,Mass Transport in Oxides, NBS Special Pub. 296 (National Bureau of Standards, Gaithersburg, Maryland, 1968), p. 149.
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Park, J.H., Natesan, K. Electronic transport in thermally grown Cr2O3 . Oxid Met 33, 31–54 (1990). https://doi.org/10.1007/BF00665668
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DOI: https://doi.org/10.1007/BF00665668