Investigation of the Effects of Reduced Sintering Temperature on Dielectric, Ferroelectric and Energy Storage Properties of Microwave-Sintered PLZT 8/60/40 Ceramics
Ajeet Kumar, Sivanagi Reddy Emani, K. C. James Raju, Jungho Ryu, A. R. James
Abstract
In this study, (Pb0.92La0.08) (Zr0.60Ti0.40) O3 (PLZT 8/60/40) ceramics were synthesized using a high-energy ball-milling technique followed by microwave sintering at different temperatures from 900 °C to 1200 °C. The optimal microwave sintering temperature for the PLZT 8/60/40 ceramics was found to be 1150 °C, which is relatively low compared with conventional sintering temperature. The sintered ceramics show the pure perovskite phase, uniform grain microstructure (1.2 µm) and high density (~99.5%). The polarization vs. electric field (P-E) hysteresis curves were used to investigate the ferroelectric and energy storage properties. The switching characteristic in P-E loops and occurrence of domain switching current in current vs. electric field (I-E) loops confirms their ferroelectric nature. The PLZT ceramics, which were sintered at 1150 °C, show the highest remnant polarization (Pr) of ~32.18 μC/cm2 and domain switching current (Imax) of ~0.91 mA with a low coercive field (Ec) of ~10.17 kV/cm. The bipolar and unipolar strain vs. electric field (S-E) hysteresis loops were also measured and the highest unipolar strain was found to be ~0.26% for the PLZT ceramics sintered at 1150 °C. The unipolar S-E curves were used to derive the piezoelectric coefficient (d33~495 pm/V) and a strain hysteresis loss (~5.8%).