PIEZOELECTRIC AND MECHANICAL-PROPERTIES OF CERIA-DOPED LEAD ZIRCONATE TITANATE CERAMICS

Phases, microstructures and properties of lead-zirconate-titanate (PZT) ceramics with the compositions Pb(Zr0.535-delta-Ce-delta-Ti0.465)O3 where delta = 0.0, 0.001, 0.01, 0.02 and 0.05 were studied. Rhombohedral and tetragonal phases were present at delta = O.O. The amount of the rhombohedral phase increased with increasing delta, and only the tetragonal phase was present for delta > 0.001. The c/a ratio of the tetragonal phase also increases with increasing delta. Particles of CeO2 were found to be present in compositions with delta > 0.01, indicating that the solubility of CeO2 is less than 1 a/o on the metals basis. The piezoelectric and electromechanical constants achieved maximum values for delta = 0.001. The hardness increased monotonically with increasing delta. The modulus of rupture and the fracture toughness, however, went through a minimum and both stayed lower than their values for delta = 0.