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Full Record for Micrograph 171
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- Micrograph no
- 171
- Brief description
- ZnO varistor
- Keywords
- ceramic
, oxygen , varistor, zinc - Categories
- Ceramic
- System
- ZnO
- Composition
- ZnO containing small amounts of oxides such as Sb2O3 and Bi2O3
- Standard codes
- Reaction
- Processing
- Produced using liquid phase sintering: gives rise to a structure consisting of conductive ZnO grains with the additional oxides being preferentially located at grain boundaries.
- Applications
- Used to short-circuit transient high voltage spikes in electronic devices. Incorporated into circuits, in parallel with the device to be protected. Acts as an insulator below a certain breakdown voltage, but as a conductor at higher voltages, due to highly non-linear I-V relationship.
- Sample preparation
- Thin section
- Technique
- Transmitted polarised light microscopy, with sensitive tint plate
- Length bar
- 250 μm
- Further information
- Contributor
- Dr K M Knowles
- Organisation
- Department of Materials Science and Metallurgy, University of Cambridge
- Date
- 09/08/02
- Licence for re-use
Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales- Related micrographs