Dy_2O_3掺杂Ba(Zr_(0.2)Ti_(0.8))O_3陶瓷介电性能及微观结构研究

Investigation on the dielectric properties and microstructure of Dy_2O_3 doped Ba(Zr_(0.2)Ti_(0.8))O_3 ceramics

采用传统固相法制备Dy2O3掺杂Ba(Zr0.2Ti0.8)O3基介电陶瓷,研究了不同掺杂含量对体系微观结构及介电性能的影响.结果表明:适量Dy2O3掺杂可抑制Ba(Zr0.2Ti0.8)O3陶瓷晶粒异常长大,使陶瓷平均粒径显著降低且粒度分布均匀;由X射线衍射分析得知,Dy2O3掺杂Ba(Zr0.2Ti0.8)O3陶瓷仍为钙钛矿结构单相固溶体;Dy2O3通过对Ba(Zr0.2Ti0.8)O3陶瓷的细晶作用以及对体系自发极化能力的消弱,进而在降低Ba(Zr0.2Ti0.8)O3陶瓷室温相对介电常数的同时有效改善了体系室温介电损耗;随着Dy2O3掺杂量的增加,Ba(Zr0.2Ti0.8)O3陶瓷铁电-顺电相变温度向负温方向移动.

The microstructure and dielectric properties of Dy203 doped Ba（ Zro.2Tio. 8 ）O3dielectric ceramics prepared by conventional solid state method were investigated with different DyzO3doping content. It is revealed that Dy203 dopant can inhibit the abnormal grain growth of Ba （Zro. 2 Tio. 8 ）03 ceramics and thus significantly reduces the average grain size of Ba（Zro.zTios） O3ceramics while inducing an uniform grain size distribution. According to the X-ray diffraction analysis, Dy203 doped Ba（ Zro 2Tio 8 ）03 ceramics are found to be single-phase solid solutions with perovskite structure. By refining the grain and weakening the spontaneous polarization in Ba （Zro.2 Tio.8） O3ceramies, DyzO3dopant can decrease the relative dielectric constant of Ba（Zro.zTio.8 ）03 ceramics at room temperature and effectively improve the dielectric loss at the same time. With the increase of DyzO3addition content, the ferroeleetric-paraelectrie phase transition temperature of Ba （Zro.2Tio.8）03 ceramics shifts ＇to lower temperature range.