Electrocaloric effect and energy-storage performance in grain-size-engineered PBLZT antiferroelectric thick films

The effects of grain size on dielectric properties, energy-storage performance and electrocaloric effect (ECE) of Pb0.85Ba0.05La0.10(Zr0.90Ti0.10)O-3 (PBLZT) antiferroelectric thick films were systematically studied. As the grain size was increased, dielectric constant of the thick films was increased, while their critical breakdown field was decreased. A giant reversible adiabatic temperature change of a dagger T = 19.9 A degrees C at room temperature was achieved in the PBLZT AFE thick film with a grain size of 0.59 A mu m. However, a huge recoverable energy-storage density of 33.6 J/cm(3) and a high efficiency of 73 % were observed in the film with the smallest grain size of 0.19 A mu m at its breakdown field, because of its excellent electric field endurance. In addition, all the samples had a low leakage current density of below 10(-6) A/cm(2) at room temperature. These results indicated that our PBLZT AFE thick films could be a promising candidate for applications in high energy-storage density capacitors and solid-cooling devices by properly controlling their grain size.