Effect of aging on the piezoelectric properties of sol-gel derived lead-free BCZT ceramics

Abstract

Aging is well observed in piezoelectric materials and plays a major role in determining the sustainabilityand performance issues of the piezoelectric based devices. Aging behavior is usually defined as the spontaneous decay of the piezoelectric properties with time. In this present study, the effect of aging on the piezoelectric properties of sol-gel derived lead-free BCZT ceramics has been investigated. During the aging process, the ferroelectric hysteresis loop was shifted along the field axis. The results revealed that the piezoelectric and dielectric properties were rapidly decreased linearly with increasing aging time and become stable with further increase in aging time. Piezoelectric (d33, g33 & kp) and dielectric properties (ϵr) were decreased approximately by 18% after 70 days. This could be due to the gradual stabilization of the ferroelectric domain structurewhich originates from the reorientation of the local defect dipoles and the migration of free oxygen vacancies towards the grain boundaries.