Piezoelectric properties of Fe2O3 doped BiYbO3-Pb(Zr,Ti)O3 high Curie temperature ceramics

The phase structure and electrical properties of BiYbO3-Pb(Zr,Ti)O3+x(mol%)Fe2O3 (BY-PZT-xFe) piezoelectric ceramics for applications at higher temperatures than those of PZT were investigated with a special emphasis on the influence of Fe2O3 content. All ceramics have a perovskite main phase with a tetragonal symmetry. The partial substitution of Fe3+ with Zr4+ and Ti4+ in the B-site caused a shrinkage of the perovskite lattice and a decreased tetragonality (c/a) with increasing x up to the solid solubility saturation at x=0.4. A lower tetragonality c/a, better grain morphology, and higher density as well as limited impurity phase were achieved at x=0.4 composition, all of which contribute to improved piezoelectric properties. The BY-PZT-xFe ceramics showed a high Curie temperature Tc up to 390 °C and good piezoelectric properties with d33 reaching 175 pC/N at x=0.4.