Multilayer ceramics for electrocaloric cooling applications

The electrocaloric effect of 0.92 Pb(Mg1/3Nb2/3)O3-0.08 PbTiO3 (PMN-8 PT) bulk ceramics and multilayer ceramic (MLC) structures is reported. The results are compared to lead-free, barium-titanate-based materials. Phase transition temperature and electrocaloric temperature change could be altered by targeted doping and this is discussed with the help of dielectric and electrocaloric measurements. By reduction of single layer thickness in MLCs, electrical loads and thus electrocaloric temperature changes of PMN-8 PT based multilayers could be increased. Simulations that outline the intrinsic cooling performance of electrocaloric MLC components in dependence of the multilayer design and operation frequency for two different modes of heat transfer are presented. The performance of the fabricated MLC layout for a driving frequency of 1 Hz is discussed in detail and an optimum layout by varying of design parameters derived. Additionally, the effect of driving frequency on the electrocaloric cooling power is investigated.