熔盐法制备Ca0.9La0.2/3Cu3Ti4O12陶瓷粉体及其介电性能研究

以CaCO3,CuO,TiO2,La2O3为反应物,NaCl,KCl为熔盐,通过熔盐法分别在700、750、800、850℃条件下合成Ca0.9La0.2/3Cu3Ti4O12陶瓷粉体。利用XRD和SEM分别对陶瓷粉体的物相结构和微观形貌进行了分析,并对其介电性能进行了测试。实验结果表明,随着合成温度的升高,陶瓷粉体的钙钛矿相含量逐渐增大,与传统固相法相比,熔盐法制备的粉体无团聚现象,耗时少。Ca0.9La0.2/3Cu3Ti4O12粉体制备的陶瓷在1 000℃烧结、测试频率在100 Hz~10 kHz时,获得优良的介电性能:介电常数大大超过104,介电损耗在0.1~0.47之间。

Preparation and Dielectric Properties of Ca0.9La0.2/3Cu3Ti4O12 Ceramic Powders by Molten Salt Methods

The perovskite Ca0.9La0.2/3Cu3Ti4O12 powders were prepared by a molten salt method at 700,750,800,850 ℃,with raw materials of CaCO3,CuO,TiO2 and La2O3 in NaCl and KCl flux salts.The phase structure,microstructure and the dielectric properties of the Ca0.9La0.2/3Cu3Ti4O12 ceramics were investigated.The results show that the perovskite(%) increased with the increasing temperature.Pure perovskite phase Ca0.9La0.2/3Cu3Ti4O12 powders were successfully synthesized by molten-salt method in NaCl-KCl flux at a low temperature of 750 ℃ for 3 h,which is 250 ℃ lower than that of the conventional solid-state reaction.Compared to the solid mixed oxide process,the molten salt synthesis was a better method for obtaining powders without aggregation in less time.At the sintering temperature of 1 000 ℃,the Ca0.9La0.2/3Cu3Ti4O12 ceramics made from powders exhibited giant dielectric constants(>104),accompanied by low dielectric loss between 0.1~0.47 in the range of 100 Hz~10 kHz.