Systematic experimental and theoretical investigation of the grain-boundary resistivities of n-doped BaTiO sub 3 ceramics

The electrical resistivities, current-voltage characteristics, and thermopowers of a series of n-doped BaTiO sub 3 ceramics having systematically varying resistivity anomalies (posistor or PTC effect) are analyzed in light of the theoretical description of the grain-boundary resistivity by a Schottk...

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Bibliographic Details
Published in:Journal of applied physics 1977-01, Vol.48 (7), p.3081-3088
Main Authors: Ihrig, H, Puschert, W
Format: Article
Language:English
Online Access:Get full text
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Summary:The electrical resistivities, current-voltage characteristics, and thermopowers of a series of n-doped BaTiO sub 3 ceramics having systematically varying resistivity anomalies (posistor or PTC effect) are analyzed in light of the theoretical description of the grain-boundary resistivity by a Schottky-type potential barrier model. The observed current-voltage dependences agree well with this model over a wide voltage range. An estimate of the surface charge reveals that the resistivity below the Curie point is governed by a residual potential barrier originating from an excess of surface charge which cannot be compensated even by an optimum alignment of the spontaneous polarization.
ISSN:0021-8979