Strain assisted electrocaloric effect in PbZr0.95Ti0.05O3 films on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate.

Solid state cooling technologies based on electrocaloric, magnetocaloric and mechanocaloric effects have received much attention during the past decade. To further improve the cooling efficiency and reduce the driving field, it is desirable to combine multiple effects in a single system. Here, we report on the caloric effects induced by both electric field and strain in PbZr0.95Ti0.05O3 films deposited on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate. The isothermal entropy change (ΔS) induced by the antiferroelectric-ferroelectric phase transition of PbZr0.95Ti0.05O3 films is calculated to be 6.78 J K(-1) kg(-1). Furthermore, the strain from 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate can reduce the electric field where ΔS reaches the maximum by as much as 50 kV/cm. The electrocaloric efficiency is also increased from 0.366 to 0.378 by the strain effect. The electrocaloric effect in an antiferroelectric material assisted by strain may lead to more efficient solid state cooling technology.