Page 14 - IPCoSME 2021

1 INTERNATIONAL POSTGRADUATE CONFERENCE ON SCIENCE AND MARINE ENVIRONMENT 2021
st
(IPCoSME 2021)
“Environmental Sustainability Enhancement Through the Collaboration of Sciences”

RA-01

INFLUENCE OF COBALT OXIDE ADDITION ON NONLINEARITY OF BARIUM
TITANATE-DOPED ZINC OXIDE-BASED VARISTOR CERAMICS

1
MUHAMAD SYAIZWADI SHAIFUDIN AND MOHD SABRI MOHD GHAZALI 1

1 Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala
Nerus, Terengganu, MALAYSIA

*Corresponding author email: mohdsabri@umt.edu.my

Abstract: The effect of cobalt oxide addition on barium titanate-doped zinc oxide varistors
were prepared by a solid-state reaction method, and the phase composition, microstructure, and

electrical properties were also investigated by SEM, XRD, and a V-I source/measure unit.
Results show that all the samples consist of BaTiO3 and Co3O4 phases coexisting with ZnO

main phase. The optimum nonlinear coefficient of about 4.8 was found in the BaTiO-doped
ZnO varistor. The microstructure analysis shows that the average grain size of the varistor

ceramics increases with increasing Co3O4 content, and it indicates that doping with Co3O4 is a

promising route to obtaining a lower varistor voltage. The highest nonlinearity of 7.2 was
gained at 0.5 wt.% Co3O4 due to the increase in barrier height and lower leakage current.

Because of the high demands for low-voltage electronics with high nonlinearity characteristics

and low leakage current, the application of the ZnO varistor at low voltage has increased
significantly.

Keywords: zinc oxide varistors; barium titanate; cobalt oxide; nonlinearity; microstructure
properties

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