A giant electrocaloric effect of a Pb0.97La0.02(Zr0.75Sn0.18Ti0.07)O3 antiferroelectric thick film at room temperature

A 2 mu m-Pb0.97La0.02(Zr0.75Sn0.18Ti0.07)O-3 (PLZST) antiferroelectric (AFE) thick film with tetragonal structure was deposited on LaNiO3/Si (100) substrates via a sol-gel technique. The electrocaloric effect (ECE) of the PLZST thick film was investigated under the influences of an external electric field and temperature. Giant ECEs (Delta T = 53.8 degrees C and Delta S = 63.9 J K-1 kg(-1)) were achieved at 5 degrees C, which was attributed to a field-induced AFE to ferroelectric (FE) phase transition. Moreover, a large Delta T of above 30 degrees C was observed in the temperature range of 5 degrees C to 25 degrees C. The maximum electrocaloric coefficient (xi(max) = 0.060 K cm kV(-1)) and refrigeration efficiency (COP = 18) of the film were also obtained at 5 degrees C. At room temperature, the values of Delta T, Delta S, COP and xi(max) were 35.0 degrees C, 39.0 J K-1 kg(-1), 14 and 0.039 K cm kV(-1) at 900 kV cm(-1), respectively. The AFE thick films with giant ECEs are promising candidates for applications in cooling systems at room temperature.