Electrocaloric effect in ferroelectric materials: From phase field to first-principles based effective Hamiltonian modeling

Electrocaloric effect (ECE) of ferroelectrics has attracted considerable interest due to its potential application in environmentally friendly solid-state refrigeration. The discovery of giant ECE in ferroelectric thin films has greatly renewed the research activities and significantly stimulated experimental and theoretical investigations. In this review, the recent progress on the theoretical modeling of ECE in ferroelectric and antiferroelectric materials are introduced, which mainly focuses on the phase field modeling and first-principles based effective Hamiltonian method. We firstly provide the theoretical foundation and technique details for each method. Then a comprehensive review on the progress in the application of two methods and the strategies to tune the ECE are presented. Finally, we outline the practical procedure on the development of multi-scale computational method without experiemtal parameters for the screening of optimized electrocaloric materials.