Role of Secondary Phase in High Power Piezoelectric PMN‐PZT Ceramics

This study reports the dielectric and piezoelectric properties of 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMN-PZT), 2 mol% MnO2-doped 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (MnO2+PMN-PZT), and 0.06Pb(Mn1/3Nb2/3)O3-0.34Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMnN+PMN-PZT) ceramics. The results show that MnO2 modification results in the formation of MgO secondary phase which promotes grain growth and reduces the electromechanical properties. We conclusively demonstrate that Mn2+ acts as pervoskite stabilizer in Pb-based (1:2) relaxors and leads to the formation of divalent oxide secondary phase. Modification with PMnN avoids the formation of MgO and provides combinatory doping effect with smaller grain sizes.