Structural variation and microwave dielectric properties of TiO 2-doped Ba(Zn 1/3Ta 2/3)O 3 ceramics

Abstract

The effect of TiO 2 on microstructure and microwave dielectric properties of Ba(Zn 1/3Ta 2/3)O 3 (BZT) ceramics was investigated. The addition of TiO 2 did not disturb the 1:2 ordering structure of the BZT ceramic. The average grain size significantly increased with the addition of TiO 2, which was attributed to the liquid phase formation. A small amount of TiO 2 increased the relative density. However, relative density decreased with the addition of the large amount of TiO 2 and it might be due to the abnormal grain growth. The Q value of the BZT significantly improved with the addition of the TiO 2 for the specimens sintered at 1580 °C and it could be explained by the increased relative density. However, for the specimens sintered at 1630 °C, Q value decreased with the addition of the TiO 2 which is attributed to the decrease of the relative density. The maximum Q× f value achieved in this investigation was about 135,000 GHz for the BZT with 1.0 mol.% TiO 2 sintered at 1580 °C for 10 h.