Effect of phase transition on electrocaloric effect in Indium substituted BaTiO3 ceramics

Abstract

In the present work the dense Ba(Ti1-xInx)O3-x/2 ceramics were prepared through a standard solid-state sintering method. Although only a tetragonal phase is detected by the X-ray diffraction in these ceramics, the coexistence of multiphase is observed by the selected area electron diffraction in two substituted ceramics. Moreover, the diffused phase transition is induced by the substitution, and this can be linked to the coexistence of multiphase in these ceramics. The maximal pyroelectric coefficient of Ba(Ti0.99In0.01)O2.995 ceramics is obviously larger than those of the other ceramics, which occurs beside the ferroelectric-ferroelectric transition. While the maximal pyroelectric coefficients of other ceramics locate beside the paraelectric-ferroelectric transition. Ba(Ti0.99In0.01)O2.995 ceramics show the largest adiabatic temperature change of 0.54 K and isothermal entropy change of 0.94 J/kg·K under an electric field of 30 kV/cm among all ceramics, and the largest electrocaloric effect strengths of 0.22 × 10−6 K m/V and 0.39 × 10−6 J m/kg·K·V under an electric field of 10 kV/cm are also obtained in this ceramic. For individual composition, the electrocaloric strength displays different tendencies, which can be linked to the diffusivity of the phase transition. From the present work, the relationship between electrocaloric effect and ferroelectric phase transition is revealed.