Dielectric, ferroelectric and piezoelectric properties of MnO2-doped Pb(Yb1/2Nb1/2)O3-Pb(Zr,Ti)O3 ceramics

0-0.8 wt% MnO2 doped 0.33Pb(Yb1/2Nb1/2)O-3-0.18PbZrO(3)-0.49PbTiO(3) (PYN-PZT) ceramics were prepared by solid state reaction method and the influence of MnO2 modification on their crystal structure, ferroelectric and piezoelectric properties of PYN-PZT ceramics was investigated. It was found that small amount of MnO2 modification did not change the crystal structure of the PYN-PZT ceramics. Whereas a large internal bias was observed which indicates the existence of defect dipoles. Piezoelectric constant (d(33)) decreased while mechanical quality factor (Q(m)) increased with the increase of MnO2 content due to the domain wall pinning effect. The influence of sintering atmosphere on the properties of Mn doped PYN-PZT ceramics was also investigated. For their high Curie temperature T-c, good piezoelectric properties and high Q(m), MnO2 doped PYN-PZT ceramics may be suggested as good candidates for high power piezoelectric applications.