Structures and enhanced electrocaloric effect in Fe-doped (Ba0.904Ca0.096) (Zr0.136Ti0.864)O-3 thin films

In this study, the electrocaloric (EC) effect was enhanced at room temperature for (Ba0.904Ca0.096) (Zr0.136Ti0.864-xFex)O-3 (BZT-0.32BCT-xFe 0 <= x <= 0.015) thin films prepared on Pt/Ti/SiO2/(100)Si substrates. The existence of an orthorhombic phase in the Fe-doped thin films at room temperature was confirmed by X-ray diffraction and Raman spectra. Tetragonal, orthorhombic, and rhombohedral phases coexist in all the investigated Fe-doped thin films. The relative content of the orthorhombic phase is most prominent at x = 0.0075. The BZT-0.32BCT-xFe thin film exhibits excellent properties with a giant EC effect (Delta T = 22.99 K, E = 1050 kV/cm, and T = 307 K) at x = 0.0075 compared to the undoped thin film, stemming from multiphase coexistence and a larger orthorhombic phase. The results of this study are useful for developing lead-free electrocaloric materials with superior properties. (C) 2021 Elsevier B.V. All rights reserved.