PENG Yue, WANG Qun, WU Jianqiang
(School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract: SnO₂ powder adsorbed with nano ZrO₂ (ZrO₂/SnO₂) was prepared with ZrOCl₂•8H₂O and ZrO₂ as raw materials by homogeneous precipitation method. Then, BaSm₂Ti₄O₁₂ ceramics were obtained with ZrO₂/SnO₂ powder, BaCO₃, TiO₂ and Sm₂O₃ as raw materials by solid state reaction method. SEM and EDS analysis proved: ZrO₂/SnO₂ powder was the composite of SnO₂ adsorbed with nano ZrO₂ sized 25 nm. XRD and SEM analysis indicated that the main crystal phase of the doped BTS ceramic was BaSm₂Ti₄O₁₂ of tungsten bronze. The modified ceramics exhibited good grain growth, uniform grain size distribution, and less porosity. Adding ZrO₂/SnO₂ powder could promote the sintering and lower the sintering temperature. The measurements of the dielectric properties showed that adding ZrO₂/SnO₂ powder could improve the microwave dielectric properties. When doped with 1wt.% ZrO₂/SnO₂ powder and sintered at 1220 ℃, the microwave dielectric ceramic with the Q value of 1890 (3 GHz), the εr of 70, and the τf of -3.3 × 10^-6 /℃ was obtained.

Key words: homogeneous precipitation method; SnO₂ adsorbed with nano ZrO₂; BaSm₂Ti₄O₁₂ microwave ceramics; tungsten bronze