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

Abstract

The effects of grain size on dielectric properties, energy-storage performance and electrocaloric effect (ECE) of Pb0.85Ba0.05La0.10(Zr0.90Ti0.10)O3 (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 ∆T = 19.9 °C at room temperature was achieved in the PBLZT AFE thick film with a grain size of 0.59 µm. However, a huge recoverable energy-storage density of 33.6 J/cm3 and a high efficiency of 73 % were observed in the film with the smallest grain size of 0.19 µm 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/cm2 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.