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 dopedlead zirconate titanate nanopowders PbPNZT, ferroelectric properties,piezoelectric properties, sol-gel methodProject supportedby the National Natural Science Foundation of China (Grant No50742007), the National High Technology Research and DevelopmentProgram of China (Grant No 2007AA03Z103), the National DefenceFoundation of China (Grant No 401050301), the Key LaboratoryFoundation of Sonar Technology of China (Grant No 9140C24KF0901),and the Scientific Project of Heilongjiang Province, China (Grant NoE2007-31).7700, 7760, 7780A modified sol-gel method is used for synthesizing Nd ion dopedlead zirconate titanate nanopowders Pb$_{1 - 3x /2}$Nd$_{x}$Zr$_{0.52}$Ti$_{0.48}$O$_{3}$ (PNZT) in an ethyleneglycol system with zirconium nitrate as zirconium source. Theresults show that it is critical to add lead acetate after thereaction of zirconium nitrate with tetrabutyl titanate in theethylene glycol system for preparing PNZT with an exact fraction oftitanium content. It has been observed that the dopant of excess Ndions can effectively improve the sintered densification and activityof the PNZT ceramics. Piezoelectric, dielectric and ferroelectricproperties of the PNZT ceramics are remarkably enhanced as comparedwith those of monolithic lead zirconate titanate (PZT).Especially, the supreme values of piezoelectric constant ($d_{33})$and dielectric constant ({it $varepsilon $}) for the PNZT are bothabout two times that of the monolithic PZT and moreover, the remnantpolarization ($P_{rm r})$ also increases by 30{%}. According tothe analysis of the structures and properties, we attribute theimprovement in electrical properties to the lead vacancies caused bythe doping of Nd ions.