Microstructure-property relationships of a zinc oxide varistor material

Technical Report · Thu Mar 01 04:00:00 EST 1979

OSTI ID:6197931

Williams, P L

Zinc oxide ceramics containing barium, cobalt, and rare earth metal oxides, which exhibit non-ohmic current-voltage characteristics, were studied. A new scanning electron microscopy technique has been developed to measure the voltage drop across grain boundaries. This was found to be approx. 2V. Detailed electron microscopic and spectroscopic observations showed that the barium and rare earth metals concentrate into small particles embedded in the cobalt-doped zinc oxide grains. No intergranular films could be detected, to within 5A resolution. Thus the nonlinear voltage characteristics are attributed to potential barriers arising from charge depletion layers formed adjacent to zinc oxide grain boundaries and two phase boundaries; experimental evidence is given to support this hypothesis.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6197931
• Report Number(s): LBL-8991
• Country of Publication: United States
• Language: English

Related Subjects

200300 -- Electric Power Engineering-- Power Transmission & Distribution-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
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360204 -- Ceramics
Cermets
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ADDITIVES
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANTIMONY COMPOUNDS
ANTIMONY OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COBALT COMPOUNDS
COBALT OXIDES
CRYSTAL STRUCTURE
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRONIC CIRCUITS
EQUIPMENT
GRAIN BOUNDARIES
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MANGANESE COMPOUNDS
MANGANESE OXIDES
MICROSTRUCTURE
NICKEL COMPOUNDS
NICKEL OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWER TRANSMISSION LINES
RESISTORS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR RESISTORS
SILICON COMPOUNDS
SILICON OXIDES
TIN COMPOUNDS
TIN OXIDES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSIENTS
TRANSITION ELEMENT COMPOUNDS
ZINC COMPOUNDS
ZINC OXIDES