Processing-structure-dielectric and piezoelectric properties correlation in PbO-based ceramics

Effects of trace impurities and additives on physical properties of piezoelectric ceramics are discussed. Experimental results are presented in the case of ceramics with the composition (Pb,Ca)TiO3 - Pb(Co,W)O3, doped with lithium and manganese ions. The nanostructure of the materials has been evidenced by HRTEM technique. Dielectric and piezoelectric properties have been measured on samples poled under an electric field of 5.5 – 7.5 kV/mm. Electromechanical coupling factors kt up to about 0.7 have been obtained. The dependence on temperature of dielectric, piezoelectric and electromechanical properties was recorded. The presence of anisotropy in the (Pb,Ca)TiO3 - Pb(Co,W)O3 -type materials was evidenced.