Electrical properties, EPR analyses and defect chemistry of Mn-doped 0.675PMN-0.325PT piezoceramics

The morphotropic phase boundary solid solution of 0.675Pb(Mg1/3Nb2/3)O-3 -0.325PbTiO(3) (0.675PMN-0.325PT) were studied. Manganese (Mn) was used as a dopant element in 0.4 mol% and 0.7 mol% ratios because of its multiple oxidation states. Sintering was done either in the air or under an oxygen-rich atmosphere. Both the effect of doping and sintering atmosphere on the electrical properties were reported. The ceramic with 0.4 mol% were exhibited higher properties such as piezoelectric charge coefficient (d(33)), dielectric constant, polarization values compared to undoped and 0.7 mol% Mn-doped ceramics. Electron paramagnetic resonance (EPR) spectroscopy was used to resolve the oxidation state of Mn in the 0.675PMN-0.325PT structure. The electrical properties were discussed and explained using defect chemistry.