Microstructure and current-voltage characteristics of ZnO-V 2O5-MnO2 varistor system

H. H. Hng; P. L. Chan

doi:10.1016/j.ceramint.2003.12.162

Microstructure and current-voltage characteristics of ZnO-V ₂O₅-MnO₂ varistor system

H. H. Hng^*, P. L. Chan

^*Corresponding author for this work

Nanyang Technological University

Research output: Contribution to journal › Conference article › peer-review

44 Citations (Scopus)

Abstract

The effects of sintering temperature and time on the microstructure and the electrical properties have been studied in a ZnO-0.5mol%V₂O ₅-2mol%MnO₂ system. The microstructure of the samples consists mainly of ZnO grains with Zn₃(VO₄)₂ as the minority secondary phase. This minor secondary phase disappears for samples sintered at 1200°C and above. An increase in sintering temperature also brings about a deleterious effect on the non-linear coefficient and the breakdown electric field. An optimum sintering time of 4h at 900°C gives the best electrical properties, with the non-linear coefficient α attaining a highest value of 31.8. Grain growth process is also investigated in terms of the phenomenological kinetic grain growth expression: Gⁿ=K _otexp(-QRT). The kinetic grain growth exponent n is observed to be 4, while the apparent activation energy Q is 193±19kJ/mol.

Original language	English
Pages (from-to)	1647-1653
Number of pages	7
Journal	Ceramics International
Volume	30
Issue number	7
DOIs	https://doi.org/10.1016/j.ceramint.2003.12.162
Publication status	Published - 2004
Externally published	Yes
Event	3rd Asian Meeting on Electroceramics - Singapore, Singapore Duration: Dec 7 2003 → Dec 11 2003

ASJC Scopus Subject Areas

Electronic, Optical and Magnetic Materials
Ceramics and Composites
Process Chemistry and Technology
Surfaces, Coatings and Films
Materials Chemistry

Keywords

A. Sintering
B. Microstructure-final
C. Electrical properties
D. ZnO
E. Varistors

Access to Document

10.1016/j.ceramint.2003.12.162

Cite this

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title = "Microstructure and current-voltage characteristics of ZnO-V 2O5-MnO2 varistor system",

abstract = "The effects of sintering temperature and time on the microstructure and the electrical properties have been studied in a ZnO-0.5mol%V2O 5-2mol%MnO2 system. The microstructure of the samples consists mainly of ZnO grains with Zn3(VO4)2 as the minority secondary phase. This minor secondary phase disappears for samples sintered at 1200°C and above. An increase in sintering temperature also brings about a deleterious effect on the non-linear coefficient and the breakdown electric field. An optimum sintering time of 4h at 900°C gives the best electrical properties, with the non-linear coefficient α attaining a highest value of 31.8. Grain growth process is also investigated in terms of the phenomenological kinetic grain growth expression: Gn=K otexp(-QRT). The kinetic grain growth exponent n is observed to be 4, while the apparent activation energy Q is 193±19kJ/mol.",

keywords = "A. Sintering, B. Microstructure-final, C. Electrical properties, D. ZnO, E. Varistors",

author = "Hng, {H. H.} and Chan, {P. L.}",

year = "2004",

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note = "3rd Asian Meeting on Electroceramics ; Conference date: 07-12-2003 Through 11-12-2003",

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TY - JOUR

T1 - Microstructure and current-voltage characteristics of ZnO-V 2O5-MnO2 varistor system

AU - Hng, H. H.

AU - Chan, P. L.

PY - 2004

Y1 - 2004

N2 - The effects of sintering temperature and time on the microstructure and the electrical properties have been studied in a ZnO-0.5mol%V2O 5-2mol%MnO2 system. The microstructure of the samples consists mainly of ZnO grains with Zn3(VO4)2 as the minority secondary phase. This minor secondary phase disappears for samples sintered at 1200°C and above. An increase in sintering temperature also brings about a deleterious effect on the non-linear coefficient and the breakdown electric field. An optimum sintering time of 4h at 900°C gives the best electrical properties, with the non-linear coefficient α attaining a highest value of 31.8. Grain growth process is also investigated in terms of the phenomenological kinetic grain growth expression: Gn=K otexp(-QRT). The kinetic grain growth exponent n is observed to be 4, while the apparent activation energy Q is 193±19kJ/mol.

AB - The effects of sintering temperature and time on the microstructure and the electrical properties have been studied in a ZnO-0.5mol%V2O 5-2mol%MnO2 system. The microstructure of the samples consists mainly of ZnO grains with Zn3(VO4)2 as the minority secondary phase. This minor secondary phase disappears for samples sintered at 1200°C and above. An increase in sintering temperature also brings about a deleterious effect on the non-linear coefficient and the breakdown electric field. An optimum sintering time of 4h at 900°C gives the best electrical properties, with the non-linear coefficient α attaining a highest value of 31.8. Grain growth process is also investigated in terms of the phenomenological kinetic grain growth expression: Gn=K otexp(-QRT). The kinetic grain growth exponent n is observed to be 4, while the apparent activation energy Q is 193±19kJ/mol.

KW - A. Sintering

KW - B. Microstructure-final

KW - C. Electrical properties

KW - D. ZnO

KW - E. Varistors

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JO - Ceramics International

JF - Ceramics International

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T2 - 3rd Asian Meeting on Electroceramics

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