Effect of MnO2 additive on the piezoelectric and dielectric properties of Ba(Zr, Ti)O3 ceramics

Ba(Zr0.06Ti0.94)MnxO3 ceramics were prepared by oxide solid state reaction method. The effects of Mn-doping on the phase structure, piezoelectric and dielectric properties of BZT ceramics were studied. Mn ions preferentially incorporated in the lattice acted as donors when the concentration of Mn ions is below 0.5 mol%, which improves the piezoelectric coefficient and decreases the dielectric loss. When the concentration of MnO2 doping is larger than 0.5 mol%, it accumulated at the grain boundaries and deteriorates the piezoelectric properties of BZT ceramics as a result of domain pinning effect. With the increase of MnO2 contew, the ferroelectric behaves more diffused. The BZT ceramics doped with x=0.3—0.4 mol% MnO2 showed improved properties with d33 value as high as 195—220 pC/N, dielectric permittivity εr of 7500 and loss tanδ of 2%.