Giant electrocaloric effect of PbTiO3 thin film tuned in a wide temperature range by the anisotropic misfit strain

• A large adiabatic temperature change over a broad temperature range was found.
• A sudden rise of adiabatic temperature change was found.
• Initial electric field narrows temperature range of adiabatic temperature change.
• The anisotropic strain can tune the temperature range of electrocaloric effect.

The influence of anisotropic in-plane strains on the electrocaloric effect (ECE) in PbTiO3 (PT) epitaxial ferroelectric thin films is investigated by using a Landau-Devonshire thermodynamic theory. The calculation results show that the anisotropic strain can tune the ECE of PT ferroelectric thin films to obtain a large adiabatic temperature change in a wide temperature range which is attributed to the shift of c-phase boundary of PT thin films under the anisotropic strains with an external electric field. These results indicate that the anisotropic strain can provide an efficient way to adjust the ECE of ferroelectric thin films to refrigerate in a wide temperature range.