Giant room temperature elastocaloric effect of PbTiO3 ferroelectric materials with 90° domain structure

Abstract

The influence of domain structures and domain switching on the elastocaloric effect in PbTiO₃ (PTO) with 90° domain structure under the applied stress field at room temperature has been studied using a phase field model. The calculation results indicate that both positive and negative elastocaloric effects can be obtained depending on the directions of the applied stress. The adiabatic temperature change (ΔT_σ) almost linearly increases with increase of the applied uniaxial stress fields, and the largest value of negative ΔT_σ is about −3.8 K which was obtained at the tensile stress field of about 2 GPa. Moreover, a negative ΔT_σ with the magnitude of −7.2 K can be obtained by controlled polarization switching under the applied stress fields. These results provide an efficient way to obtain a large elastocaloric effect in ferroelectric materials through domain engineering at room temperature.