Abstract
This study reported the effect of adding excess niobium in higher amount (up to 1.5 mol% Nb2O5) than that reported in any other literature. Increasing in mol% Nb2O5led to a formation of secondary phase. The average grain size decreased with higher Nb2O5addition and it also inhibited grain growth and controlled grain uniformity in the microstructure. The presence of needle-like secondary phase when added >0.3mol% Nb2O5aided grain growth inhibition resulting in finer matrix grain. Addition of Nb2O5more than 0.9 mol% in regardless of sintering time showed two dielectric peaks which could be related to secondary phase in the microstructure.
Keywords:
Acknowledgments
The authors would like to thank the Department of Materials Science and Engineering, Silpakorn University and Metallurgy and Materials Science Research Institute, Chulalongkorn University for financial support.