Enhanced thermal energy conversion and dynamic hysteresis behavior of Sr-added Ba0.85Ca0.15Ti0.9Zr0.1O3 ferroelectric ceramics

This paper deals with a study of Ba0.85Ca0.15−xSrxTi0.9Zr0.1O3 (BCT-BZT-Sr) (x = 0%, 5%, 10% and 15%) polycrystalline ceramics for thermal energy conversion applications using the Olsen cycle. A maximum energy conversion density of 108 kJ/m3 was observed in pristine BCT-BZT for cycle operating at 30–90 °C and 0–20 kV/cm. Moreover, the samples with Sr contents (x) of 5%, 10% and 15% display an energy conversion density of 179 kJ/m3, 149 kJ/m3 and 200 kJ/m3, respectively. The Sr addition almost double the energy conversion over the pristine sample under the similar conditions. Also, the temperature (T)-dependent dynamic hysteresis scaling relations for coercive field (EC) and remnant polarization (Pr) were systematically investigated. The power-law scaling exponents are obtained for EC versus T as EC ∝ T−0.65, EC ∝ T−0.61, EC ∝ T−0.56 and EC ∝ T−0.63 for the samples with Sr contents of 0%, 5%, 10% and 15%, respectively. Similarly, the scaling relations for Pr are Pr ∝ T−1.59, Pr ∝ T−1.59, Pr ∝ T−1.36 and Pr ∝ T−1.32 for the samples with Sr contents of 0%, 5%, 10% and 15%, respectively.