Electrical properties of Ta2O5-doped TiO2 varistor ceramics sintered at low-temperature

摘要

TiO2-based varistor ceramics doped with 0.25-1.00 mol% Ta2O5 were prepared by the conventional solid state reaction technique at 1300 degrees C and the effects of Ta2O5 substitution on their electrical properties have been studied. The results showed that the Ta2O5 dopant played an important role in the formation of the grain boundary barriers. Good electrical properties with E-1 (mA)=14.9 V/mm, alpha=4.48, epsilon(r)=9.68 x 10(4), tan delta=0.36 were obtained for 0.50 mol% Ta2O5 addition. These results indicate the 99.5 mol% TiO2+0.50 mol% Ta2O5+2 wt% (0.723 mol% Bi2O3+1 mol% B2O3) composition might be a suitable candidate for capacitor varistor functional device. (C) 2015 Published by Elsevier Ltd and Techna Group S.r.l.