Low temperature sintering and dielectric properties of (Zr0.8Sn0.2)TiO4 microwave ceramics using La2O3/BaO additives

The effects of La2O3/BaO additives on the sintering behavior and dielectric properties of (Zr0.8Sn0.2)TiO4 (ZST) microwave ceramics were investigated. With La2O3/BaO additives, the sintering temperatures can be effectively lowered. The dielectric properties of ZST ceramics were strongly dependent on the amount of La2O3/BaO additives. As the amount of La2O3/BaO additives increased from 0.5 to 2.0 wt.%, the dielectric constants εr increased following the trend with density and the τf values of dense sintered ZST ceramics increased from +1.3 to +18.3 ppm °C−1 steadily. The quality values Q first increased, reached a maximum at 1.0 wt.% La2O3/BaO, and then decreased with the further increase of La2O3/BaO amount for all sintering temperatures. The 1.0 wt.% La2O3/BaO-doped ZST ceramics sintered at 1350 °C for 4 h had the optimum dielectric properties: εr=38; τf=+5.6 ppm °C−1; Q=11 575 (1.8 GHz). At the level of 0.5–2.0 wt.% additives, no second phase was observed by the X-ray diffraction (XRD) analysis.