Enhancement of the electrocaloric cooling by electric field reversal: simulation and experiment

An improved thermodynamic cycle is proposed, where the cooling effect of an electrocaloric refrigerant is enhanced by applying a reversed electric field. In contrast to conventional adiabatic heating or cooling by on-off cycles of the external electric field, applying a reversed field is significantly improving the cooling efficiency, since the variation in configurational entropy is increased. By comparing results from computer simulations using Monte-Carlo algorithms and experiments using direct electrocaloric measurements, we show that the electrocaloric cooling efficiency can be enhanced by more than 20\% in standard ferroelectrics and also relaxor ferroelectrics, like Pb(Mg$_{1/3}$/Nb$_{2/3}$)$_{0.71}$Ti$_{0.29}$O$_3$.