Materials efficiency of electrocaloric lead scandium tantalate multilayer capacitors

Electrocaloric materials in the shape of multilayer capacitors are excellent working bodies to build cooling devices as they can exhibit large changes in temperature triggered by changes in voltage over large range of temperatures. However, high electric fields are required to drive such a large effect and yet, their efficiency has been overlooked. Here we report on the materials efficiency of lead scandium tantalate multilayer capacitors. Hence, we show that they can exchange 25 times more heat than the electrical work required to generate this heat. Besides, we observed that these multilayers capacitors are four times less efficient than lead scandium tantalate bulk ceramics for the same heat exchanged, though they exhibit a large electrocaloric effect on a much larger temperature range. Moreover, their efficiency is comparable to Gd, the prototypical magnetocaloric material. This work ultimately provides an extensive picture of the pros and cons of lead scandium tantalate.