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Conductivity Mechanisms in Acceptor Doped KTaO3 Crystals

Published online by Cambridge University Press:  28 February 2011

T. Scherban ,
S.Q. Fu  and
A.S. Nowick
T. Scherban
Affiliation:
Henry Krumb School of Mines, Columbia University, New York, NY 10027
S.Q. Fu
Affiliation:
Henry Krumb School of Mines, Columbia University, New York, NY 10027
A.S. Nowick
Affiliation:
Henry Krumb School of Mines, Columbia University, New York, NY 10027
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Abstract

The electrical conductivity of perovskite—structured KTaO3 crystals acceptor doped with Co, Cu or Fe was investigated after treatments in oxidizing and reducing atmospheres under both wet and dry conditions. Isotope effect measurements (using H2O vs. D2O) show that, after treatments in wet gases of low P(O2), all the crystals are primarily protonic conductors, through a process of proton hopping with an activation energy close to 0.84 eV. Electron hole conduction dominatesat high P(O2) in the case of Fe and Cu doping. For Co—doped crystals, the conductivity is independent of P(O2) up to 1 atm., indicating that ionic conduction predominates. There is no evidence of oxygen vacancy migration, leading to the conclusion that the activation energy for that process Is relatively high.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 210: Symposium L – Solid State Ionics II , 1990 , 663
Copyright
Copyright © Materials Research Society 1991

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