A位替代对Bi_2O_3-ZnO-Nb_2O_5陶瓷介电性能的影响

Effect of A Site Substitution on Dielectric Properties of Bi_2O_3-ZnO-Nb_2O_5 Based Ceramics

研究了A位Nd3+、Dy3+、Y3+、Er3+、Sb3+替代对Bi2O3-ZnO-Nb2O5(BZN)基陶瓷结构和介电性能的影响。在替代量x≤0.4时,替代后的样品均保持单一的单斜焦绿石结构;Y3+替代的样品在960℃致密成瓷,Nd3+、Dy3+、Sb3+替代的样品在1 000℃致密成瓷,而Er3+替代的样品在1 050℃致密成瓷,因此,不同离子替代可有效地降低烧结温度;Nd3+、Dy3+、Y3+、Er3+替代样品的介电常数温度系数先增大后减小,当替代量x=0.4时,Y3+替代的样品的介电常数温度系数突然增大;而Sb3+替代样品的介电常数温度系数由286.842 1×10-6急剧减小到-171×10-6。因此,选择合适的离子替代可以获得性能很好的具有温度补偿特性的陶瓷(NPO)介质材料。

The structure and dielectric properties of BZN-based pyrochlore ceramics with substitution of Nd3＋ , Dy3＋ ,y3＋ ,Er3＋ ,Sh3＋ for A site were investigated. The sample exhibited a single monoclinic pyrochlore phase when Nd3＋ ,Dy3＋ ,y3＋ ,Er3＋ ,Sb3＋ substitutionS0.4; The sintering temperature was 960 ℃ for substitution of y3＋, the sintering temperature was 1 000 ℃ for substitution of Nd3＋ ,Dy3＋ ,Sb3＋ , but the sintering temperature was 1 050 ℃ for substitution of Er3＋ , The sintering temperature decreaseed for the different ions substitution; Temperature coef- ficient （ae） of dielectric constant increased firstly, then it decreased with substitution of Nd3＋ , Dy3＋ , y3＋ , Er3＋ when x= 0.4. The temperature coefficient of dielectric constant increased with substitution of y3＋ ; while the temperature coefficient of dielectric constant decreased rapidly from 286. 842×10^-6 to --171×10^-6 with substitution of Sb3＋. The result of dielectric behaviors indicated that proper ion substation was an effective way to get NPO dielectric materials.