Electron spectroscopic studies of electrically active grain boundaries in ZnO

The non-ohmic behaviour of ZnO-ceramics is based on back-to-back Schottky barriers between adjacent grains. Here grain boundaries of ZnO-varistors are studied by a variety of surface sensitive techniques to try to correlate their macroscopic electrical behaviour with the physico-chemical properties...

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Bibliographic Details
Published inSurface science Vol. 189; pp. 294 - 299
Main Authors Stucki, F., Brüesch, P., Greuter, F.
Format Journal Article
LanguageEnglish
Published Elsevier B.V 01.10.1987
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Summary:The non-ohmic behaviour of ZnO-ceramics is based on back-to-back Schottky barriers between adjacent grains. Here grain boundaries of ZnO-varistors are studied by a variety of surface sensitive techniques to try to correlate their macroscopic electrical behaviour with the physico-chemical properties of the interfaces. Severe electrical degradation causes a large increase in leakage current at low voltages and deformes the Schottky barriers. We show for the first time that electrical ageing of interfacial potential barriers is related to chemical changes on the monolayer scale. The electromigration of oxygen ions perpendicular to the grain boundaries is responsible for the reduction of the barrier height.
ISSN:0039-6028
1879-2758
DOI:10.1016/S0039-6028(87)80445-4