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Interference Effect between Electron and Ion Flows in Semiconducting Fe3−δO4

Published online by Cambridge University Press:  18 March 2011

Jeong-Oh Hong
Affiliation:
Solid State Ionics Research Lab., School of Materials Science and Engineering, Seoul National University, Seoul 151-742, Korea
Han-Ill Yoo
Affiliation:
Solid State Ionics Research Lab., School of Materials Science and Engineering, Seoul National University, Seoul 151-742, Korea
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Abstract

The effective valence, zFe–αFe*, of mobile Fe-ions (Fe2+, Fe3+) in semiconducting Fe3O4 was determined at elevated temperatures via the electrotransport experiment in association with the literature data on the cation diffusivity and total electrical conductivity. It has been found that the value for zFe–αFe* varies systematically from below 2 up to 3 with oxygen partial pressure at a fixed temperature. The effective valence is determined not only by the mobility difference of Fe2+ and Fe3+ ions (zFe), but also by the cross effect between the cations and electrons upon their transfer (αFe*). A value of zFe–αFe* between 2 and 3 may be attributed to the mobility difference between Fe2+ and Fe3+ ions even in the absence of the cross effect, but the values of zFe–αFe* < 2 clearly indicate that the cross effect is in play in Fe3O4.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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References

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