Piezoelectric properties in PMN–PT relaxor ferroelectrics with MnO2 addition

The temperature dependence of piezoelectric properties in the PMN–PT relaxor ferroelectric system with MnO2 addition was studied in the temperature range from −40 to 30°C. Samples were poled at −40°C and the piezoelectric properties were measured by resonance–antiresonance method. Qm increased by increasing the doping contents of Mn. When 0.5 wt.% MnO2 was doped, Qm increased from 95 to 480. From the experimental results, it is predicted that Mn behaves as an acceptor and a domain pinning element. The effects of MnO2 observed in PZT-based normal ferroelectrics were also confirmed in PMN-based relaxor ferroelectrics.