中文摘要：

采用常规陶瓷工艺制备了0.2Pb（Zn1/3Nb2/3）O3-0.8Pb（Zr0.5Ti0.5）O3（0.2PZN-0.8PZT）三元系陶瓷,系统研究了Ag掺杂对体系微观结构及电学性能的影响。结果表明,Ag在钙钛矿中的溶解限约为0.1%（质量分数）。低于溶解限,Ag以离子掺杂形式进入钙钛矿晶格置换A位的Pb2＋,以受主掺杂机制影响体系电学性能;高于溶解限,过量的Ag以单质形式沉积在晶界,弥散分布在0.2PZN-0.8PZT相中。Ag单质使陶瓷体系形成复相结构,在烧结降温阶段产生内应力,改变了材料的电畴结构,并影响陶瓷的直流电阻率和压电性能。

英文摘要：

0.2Pb（Zn1/3Nb2/3）O3-0.8Pb（Zr0.5Ti0.5）O3（0.2PZN-0.8PZT） ceramics were prepared by conventional mixed oxide method,and the effect of Ag doping on the microstructure and electric properties of 0.2PZN-0.8PZT was investigated in detail.The results revealed that the solubility limit of Ag＋ in perovskite lattice was near 0.1%.Below the solubility limit,Ag＋ entered A site of ABO3 structure to replace Pb2＋,and played as doping role to influence the electric properties.While at high doping level above the solubility limit,the excess Ag accumulated at grain boundaries as the form of pure Ag particles,which were homogenously dispersed in the 0.2PZN-0.8PZT matrix.The Ag particles induced the inner stress during the cooling stage after sintering,resulting in the transformation of domain structure and the variation of the resistivity and piezoelectric properties.