Domain wall contribution to the electrocaloric effect in BaTiO3 nanoparticle: a phase-field investigation

The domain wall contribution to the electrocaloric effect (ECE) in the BaTiO3 (BTO) nanoparticle at room temperature is investigated using a phase-field model combined with thermodynamics analysis. The results show that the domain structure which relates to the size has a significant effect on the ECE in the BTO nanoparticle. When the size of the BTO nanoparticle decreases, the domain structure undergoes a transition from a multidomain structure to a monodomain structure. In the multidomain BTO nanoparticle, the adiabatic temperature change increases with increasing of the domain wall density and domain wall width. In the monodomain BTO nanoparticle, the adiabatic temperature change almost retains constant with the value of 0.95 K which is smaller than that in the multidomain structure. The variation of the adiabatic temperature change at different domain structure is attributed to the domain wall contribution to ECE.