Novel route for preparation of high voltage varistor powder
- Bhabha Atomic Research Centre, Navi Mumbai (India). Powder Metallurgy Div.
A novel technique for preparing ZnO varistor powder is described. It involves preparation of gel by adding citric acid to nitrate solution of varistor constituents. The gel on subsequent calcination forms submicron reactive varistor powder that exhibits the homogeneity and stoichiometric control associated with the chemical methods of preparation. SEM and BET surface area measurements show the resultant powder to comprise crystallite of submicron size. High field varistors with good nonlinear coefficient result from sintering at 1,150 C for 1 hour. The high value of nonlinear coefficient of the varistor sample can be attributed to the more uniform distribution of dopants and formation of more varistor active grain boundaries. The electrical characteristics of the citrate gel derived varistor are compared to those of a varistor sample prepared through the urea route.
- OSTI ID:
- 561896
- Journal Information:
- Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 11 Vol. 32; ISSN MRBUAC; ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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