SPP 1599:  Caloric Effects in Ferroic Materials: New Concepts for Cooling

• Subject Area: Materials Science and Engineering ; Physics ; Thermal Engineering/Process Engineering
• Term: from 2012 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 198599533

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 utilised. The recent discovery of giant entropy changes associated with first order phase transformations promises higher cooling efficiency. Ferroic transitions enhance the entropy change of magneto-, elasto-, baro- and electro-caloric effects. Furthermore, as the refrigerant is in a solid state, the technology completely eliminates the need for high global-warming potential halo fluorocarbon refrigerants. 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, the requirement of a large magnetic field (> 2 T) hampers wide industrial and commercial applications. It is expected that this obstacle can be overcome by materials with lower hysteresis and by using other types of fields (stress, electric). In order to accelerate research on ferroic cooling this Priority Programme will address the following major challenges for introducing ferroic materials in practical cooling applications: Understanding of the underlying mechanisms, energy efficiency, effect size, hysteresis, fatigue and system integration. It covers the following "ferroic-caloric" material classes and combinations thereof: ferromagnetic, ferroelectric and ferroelastic materials. The complexity of ferroic cooling requires a close collaboration of materials scientists, engineers and physicists. The aim of this Priority Programme is to bring groups from these disciplines together to combine their complementary expertise from basic research to application.

• DFG Programme: Priority Programmes
• International Connection: Switzerland

Projects

• A Elastocaloric Shape Memory Cooling Demonstrator Unit - Design & Fabrication; Modeling; Material Optimization (Applicants Eggeler, Gunther ;  Schütze, Andreas ;  Seelecke, Stefan )
• A high frequency magnetocooling cycle and direct Delta T measurements in ferroic thin films and low volume samples (Applicant Hägele, Daniel )
• Ab initio study on the coupling of lattice and magnetic degrees of freedom and the role of interfaces in magneto-caloric materials (Applicant Hickel, Tilmann )
• Coarse grained models for large scale atomistic simulations of spin and lattice dynamics (Applicant Opahle, Ingo )
• Compositional and Microstructural Optimization and Microstructural, Thermal and Mechanical Assessment of NiTi Shape Memory Alloys for Ferroelastic Cooling (Applicant Eggeler, Gunther )
• Cooling power in lead-free electrocalorics (Applicant Rödel, Jürgen )
• Coordination Funds (Applicant Fähler, Sebastian )
• Coordination of SPP 1599 FerroicCooling (Applicant Fähler, Sebastian )
• Coupling phenomena in magnetocaloric materials: From thin layers to composites (Applicants Hickel, Tilmann ;  Hütten, Andreas ;  Waske, Anja )
• Design of electrocaloric multilayer refrigerators via multi-scale modeling (Applicants Albe, Karsten ;  Xu, Bai-Xiang )
• Development and Validation of a NiTi-Based Ferroelastic Cooling Demonstrator (Applicant Schütze, Andreas )
• Development of perovskite-type ceramics and device structures for electrocaloric applications (Applicant Gebhardt, Sylvia )
• Elastocaloric Ti-Ni based Films and Devices - Materials (Applicant Quandt, Eckhard )
• Elastocaloric TiNi-based Films and Devices (Applicants Kohl, Manfred ;  Quandt, Eckhard )
• Electrocaloric effect in lead-free relaxor ceramics and composites (Applicants Lupascu, Doru Constantin ;  Rödel, Jürgen )
• Electrocaloric multilayer cooling device concepts (Applicant Gerlach, Gerald )
• First-principles simulation of magnetocaloric and electrocaloric effects in nanostructured films (Applicant Grünebohm, Anna )
• In-situ XRD for studying the effects of external fields on the structure of magnetocaloric materials (Applicant Waske, Anja )
• Methodological Development and Design of Electrocaloric Cooling Systems for Electric Vehicle Applications (Applicant Raatz, Annika )
• Novel caloric materials by mastering hysteresis: a material science approach (Applicant Gutfleisch, Oliver )
• Novel Caloric Materials by Mastering Hysteresis: Combinatorial Development of Magnetocaloric Materials (Applicant Ludwig, Alfred )
• Novel caloric materials by mastering hysteresis: from basic mechanisms to applications (Applicants Acet, Mehmet ;  Gruner, Markus ;  Gutfleisch, Oliver ;  Wende, Heiko )
• Novel caloric materials by mastering hysteresis: microscopic understanding by element-specific studies (Applicant Wende, Heiko )
• Understanding magnetocaloric and electrocaloric effects using epitaxial films (Applicants Fähler, Sebastian ;  Hühne, Ruben )

• Spokesperson: Privatdozent Dr. Sebastian Fähler