Authors contributed to establish the DFG Priority Program SPP 1599. More details on this SPP can be found at www.FerroicCooling.de. We acknowledge fruitful discussions with J. Rödel.
Caloric Effects in Ferroic Materials: New Concepts for Cooling†
Article first published online: 22 NOV 2011
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Volume 14, Issue 1-2, pages 10–19, February 2012
How to Cite
Fähler, S., Rößler, U. K., Kastner, O., Eckert, J., Eggeler, G., Emmerich, H., Entel, P., Müller, S., Quandt, E. and Albe, K. (2012), Caloric Effects in Ferroic Materials: New Concepts for Cooling. Adv. Eng. Mater., 14: 10–19. doi: 10.1002/adem.201100178
- Issue published online: 7 FEB 2012
- Article first published online: 22 NOV 2011
- Manuscript Accepted: 1 SEP 2011
- Manuscript Received: 7 JUL 2011
Refrigeration is one of the main sinks of the German and European electricity consumption and accordingly contributes to worldwide CO2 emissions. High reduction potentials are envisaged if caloric effects in solid materials are used. The recent discovery of giant entropy changes associated with ferroelastic phase transformations promises higher efficiency. Ferroic transitions enhance the entropy change of magneto-, elasto-, baro-, and electro-caloric effects. Furthermore, because the refrigerant is in a solid state, this technology completely eliminates the need for halofluorocarbon refrigerants having a high global-warming potential. The smaller footprint for operation and the scalable mechanism open up further applications such as cooling of microsystems. While the principal feasibility of magnetocaloric refrigeration is already evident, it requires large magnetic fields (>2 T) which hampers wide industrial and commercial application. It is expected that this obstacle can be overcome by materials with lower hysteresis and by using stress- or electric fields. In order to accelerate research on ferroic cooling, the Deutsche Forschungsgemeinschaft (DFG) decided to establish the priority program SPP 1599 in April 2011. In this article we will address the major challenges for introducing ferroic materials in practical cooling applications: energy efficiency, effect size, and fatigue behavior. Solid state cooling in this sense can be based on the following “ferroic-caloric” classes of materials: ferroelastic shape memory alloys, ferromagnetic shape memory alloys, and ferroelectric materials and their possible combinations in materials with “multicaloric” effects. The open questions require the interdisciplinary collaboration of material scientists, engineers, physicists, and mathematicians.