Ultra high strain properties of lanthanum substituted PZT electro-ceramics prepared via mechanical activation

• PLZT comparable with PMN–PT and their hot-pressed counterparts synthesized.
• HEM applied for ceramic preparation at reduced sintering temperature.
• Strain value (0.27%) comparable to previous reported values for PLZT 8/60/40.
• The electric field induced (strain) hysteresis loss was also found to be very less.

Substitution of lanthanum at the A sites of perovskite lead zirconate titanate ceramics shows an improvement in the structural and electrical properties. (Pb0.92La0.08)(Zr0.60Ti0.40)O3 (PLZT 8/60/40) was prepared using high energy mechano-chemical milling. The effect of milling on the microstructure and electrical properties of PLZT 8/60/40 has been studied. X-ray diffraction shows the phase formation after milling itself. TEM was used to measure the particle size. The SEM image of the sintered pellet shows a dense microstructure and the average grain size was found to be <1.5 μm. Electrical properties of the ceramics were characterized. Piezoelectric charge coefficient (d33) was found to be 561 pC/N. Resonance studies were performed on poled ceramics and the electromechanical coupling factor was calculated by the resonance method. The PLZT 8/60/40 composition showed a well saturated and uniform P–E hysteresis loop with remanent polarization (Pr) of 33.29 μC/cm2 and a coercive field (Ec) of 10.57 kV/cm. Electric field induced strain (S–E loop) shows a value of ∼0.27% with minimum loss.