Effect of Ga₂O₃on Microstructure and Microwave Dielectric Properties of Ba(Zn_1/3Ta_2/3)O₃Ceramics

Abstract

The effect of Ga2O3 on the microstructure and microwave dielectric properties of Ba(Zn1/3Ta2/3)O3 (BZT) ceramics was investigated. The 1:2 ordered hexagonal structure disappeared with the addition of Ga2O3. The average grain size of BZT increased with the addition of Ga2O3, which was attributed to the liquid phase formation. The liquid phase contains high concentrations of Ba and Ga ions. The relative density of the specimen increased with the addition of a small amount of Ga2O3 but it decreased when the Ga2O3 content was increased. Variation of the dielectric constant with Ga2O3 addition was similar to that of the relative density and ranged between 27 and 29. The temperature coefficient of resonant frequency decreased with increasing Ga2O3. The Q×f value of BZT was about 88,000 GHz and it significantly improved with the addition of Ga2O3. The maximum Q×f value achieved in this investigation was about 161,000 GHz for the BZT with 1.0 mol% Ga2O3 sintered at 1550°C for 10 h.