EFFECTS OF LANTHANUM DOPING ON DIELECTRIC AND ELECTROSTRICTIVE PROPERTIES OF LEAD MAGNESIUM NIOBATE-LEAD TITANATE CERAMICS

Effects of lanthanum doping on dielectric and electrostrictive propert ies of PMN-PT ceramics were investigated. By means of adjusting the am ount of La3+ doping, not only was the emergence of pyrochlore phase de trimental to the dielectric properties effectively avoided, but also L a:PMN-PT ceramics with microstructure of uniform grain size and good e lectrostrictive properties were obtained. The XRD results indicated th ere existed almost pure cubic perovskite phase in La: PMN-PT ceramics. At the same time, the dependence of dielectric and electrostrictive p roperties upon firing conditions was also studied.