摘要
制备 Pb(Zn_(1/3)Nb_(2/3))O_3(PZN)基陶瓷电容器,最主要的问题是形成有害于介电性质的焦录石相。实验表明,固相反应法很难合成钙钛矿结构的 PZN 陶瓷,于1000经固相反应的产物是含立方焦录石的混合物,在 PZN 中添加0.53mol 的 PFW,试样中的钙钛矿相超过97%。通过对 Pb(Fe_(2/3)W_(1/3))O_3(PFW)结晶化学和烧结机理的分析,证明在 PZN 中添加 PFW 能减少或抑制焦录石的形成。本文报导了 PZN-PFW 二元系陶瓷的相关系和介电性质,探讨了钙钛矿相的形成机理。
The formation of pyrochlore phase,which is harmful to the dielectric properties,is an im- portant problem for the preparation of Pb(Zn_(1/3)NO_(2/3))O_3(PZN) based capasitor ceramics.It is found that the product of solid state reactions at 1000℃ is a mixture containing cubic pyrochlore,and it is difficult to synthesize PZN ceramics with perovskite structure by solid state reactions.The addition of 0.53 mole Pb(Fe_(2/3)W_(1/3))O_3(PFW) to PZN results in specimens with more than 97% of perovskite phase.By the examination of crystal chemistry and sintering mechanism of PFW,it has been shown that the addition of PFW can suppress the formation of pyrochlore.The phase relations in the PZN- PFW binary system and the dielectric properties of ceramics in this system are reported in the paper. The formation mechanism of perovskite phase is discussed.
关键词
介电性
PZN陶瓷
电工陶瓷
PZN-PFW binary system
perovskite phase pyrochlore phase
dielectric properties
tolerance factor
electronegativity difference
