Structural and electrical properties of Nd ion modified lead zirconate titanate nanopowders and ceramics

A modified sol-gel method is used for synthesizing Nd ion doped lead zirconate titanate nanopowders PbPNZT, ferroelectric properties, piezoelectric properties, sol-gel methodProject supported by the National Natural Science Foundation of China (Grant No 50742007), the National High Technology Research and Development Program of China (Grant No 2007AA03Z103), the National Defence Foundation of China (Grant No 401050301), the Key Laboratory Foundation of Sonar Technology of China (Grant No 9140C24KF0901), and the Scientific Project of Heilongjiang Province, China (Grant No E2007-31).7700, 7760, 7780A modified sol-gel method is used for synthesizing Nd ion doped lead zirconate titanate nanopowders Pb$_{1 - 3x / 2}$Nd$_{x}$Zr$_{0.52}$Ti$_{0.48}$O$_{3}$ (PNZT) in an ethylene glycol system with zirconium nitrate as zirconium source. The results show that it is critical to add lead acetate after the reaction of zirconium nitrate with tetrabutyl titanate in the ethylene glycol system for preparing PNZT with an exact fraction of titanium content. It has been observed that the dopant of excess Nd ions can effectively improve the sintered densification and activity of the PNZT ceramics. Piezoelectric, dielectric and ferroelectric properties of the PNZT ceramics are remarkably enhanced as compared with those of monolithic lead zirconate titanate (PZT). Especially, the supreme values of piezoelectric constant ($d_{33})$ and dielectric constant ({\it $\varepsilon $}) for the PNZT are both about two times that of the monolithic PZT and moreover, the remnant polarization ($P_{\rm r})$ also increases by 30{\%}. According to the analysis of the structures and properties, we attribute the improvement in electrical properties to the lead vacancies caused by the doping of Nd ions.