Ferroelectric aging and recoverable electrostrain in BaTi0.98Ca0.02O2.98 ceramics

BaTi0.98Ca0.02O2.98 (BTC) ceramics where Ca2+ acts as an acceptor dopant show ferroelectric aging, reversible domain switching, and a nonlinear recoverable electrostrain of ∼0.04% at ∼11 kV/cm. This behavior is attributed to the mobility of oxide-ion vacancies created by the acceptor doping mechanism and a tendency for the defect symmetry to align with the crystal symmetry. The recoverable strain in unpoled ceramics is of comparable magnitude to that obtained from the linear piezoelectric effect in poled hard-PZT ceramics at a similar applied field. These preliminary results demonstrate the potential of BTC as a ‘Pb-free’ ceramic to achieve significant recoverable electrostrain.