Electrocaloric response in lanthanum-modified lead zirconate titanate ceramics

Recent findings of a large electrocaloric (EC) effect in polymeric and inorganic ferroelectric materials open a potential possibility of development of solid-state cooling or heating devices of new generation with better energy efficiency that may be less harmful for the environment. We investigate by using direct measurements, the temperature and electric field dependence of the electrocaloric response in Pb_1-xLa_x(Zr_yTi_1-y)_1-x/4O₃ bulk ceramics (PLZT) with x = 0.06 and 0.12. Here, the properties of the EC response were probed in a part of the PLZT composition phase diagram with low y = 0.40 composition, in which the EC effect was not previously studied. Measurement results show the existence of the sizeable EC response in the 12/40/60 PLZT sample with the EC temperature change (ΔT_EC) of 2.92 K at 430 K and 80 kV/cm. This value exceeds previously obtained ΔT_EC values in relaxor ferroelectric x/65/35 PLZT compositions, rivaling the best EC response in lead magnesium niobate-lead titanate ceramics. The electrocaloric responsivity (ΔT/ΔE) value of 0.41 × 10⁻⁶ Km/V determined at a lower electric field of 20 kV/cm and 410 K is comparable to those observed in other perovskite ferroelectrics.