Multifunctional response of lanthanum-modified PZT relaxor ferroelectric system with improved electrocaloric effect and energy storage performance

摘要

A systematic investigation of both electrocaloric effect (ECE) and energy storage properties is presented in the Pb0.88La0.08(Zr0.6Ti0.40)O-3 relaxor system. The ECE, studied from direct and indirect methods, revealed an electrocaloric temperature change (Delta T) around 1.6 K, under an applied electric field of 60 kV/cm at room temperature, with a corresponding electrocaloric strength (Delta T/Delta E) around 0.03 K cm/kV. The temperature dependence of Delta T displayed its maximum value (similar to 2.32 K) around the freezing temperature (T-f), which is known as a critical temperature for relaxor ferroelectrics, thus suggesting an important contribution of the polar nanoregions to the electrocaloric properties. This result, together with the observed recoverable energy density (J(r)) value around 0.43 J/cm(3) and a relatively high discharge energy efficiency, reveals the studied system as a promising material for application in multifunctional devices based on high ECE materials combined with excellent energy storage performance. (C) 2020 Elsevier B.V. All rights reserved.